This is a paper I wrote covering the effects of grazing tall fescue on cattle. I learned a lot on the topic and I hope you will too! Enjoy!
Performance of cattle grazing endophyte infected tall fescue compared novel endophyte or endophyte free tall fescue
ABSTRACT
Tall fescue (Festuca arudinacea) is a cool-season forage used by many cattle producers for grazing cattle. Unfortunately, a large proportion of tall fescue stands in the United States are infected with an endophyte fungus that produces toxins called ergot alkaloids. Consumption of these ergot alkaloids provides negative side effects in cattle and other livestock species, collectively referred to as “fescue toxicosis.” A review of recent literature compared the impacts of growing cattle grazing endophyte-infected fescues to novel endophyte and non-infected tall fescue stands. The results from this show that cattle performance is reduced from grazing endophyte-infected tall fescue stands with results being reduced body weight gains, serum prolactin levels, DMI, and an increase in rectal temperatures. These side effects can be avoided by grazing stockpiled forages during the late fall and winter, when ergot alkaloid concentrations are at the lowest levels, or by replacing endophyte-infected tall fescue stands with novel endophyte or non-infected tall fescues stands.
INTRODUCTION
Tall fescue (Festuca arudinacea) is one of the leading perennial cool-season forages for a large portion of the United States. This cool-season forage is optimal for cattle production because of its stand persistence. The plant is very tolerant of minor flooding, moderate drought, intensive grazing, poor fertility, and heavy traffic. The majority of the plant’s growth occurs during the spring season and often comes close to dormancy during summer months (Curtis, 2007). As optimal as this forage may appear, cattle usually exhibit lower productivity when grazing tall fescue due to toxins found in the mature plant.
A small fungus, known as an endophyte (Neotyphodium coenophialum), grows between the cells of the plant and produces a toxin. This toxin is the cause of lowered productivity for cattle grazing endophyte infected (E+) tall fescue. The toxins, ergot alkaloids, are present in the seed when planted. After germination of the plant, the endophyte lives at the base of the plant, but does not grow into the leaves. During the reproductive stages, the endophyte grows between the cells of the stem and the toxins become concentrated in the seeds of the plant (Bacon, 1993). Collectively, the symptoms from consumption of the ergot alkaloids are known as “fescue toxicosis.” Previous research has shown that cattle with fescue toxicosis often exhibit rough hair coat, reduced feed intake, high respiration rate, elevated body temperature, reduced milk production because of lowered prolactin levels, reduced body weight gain, lower conception rates, excessive salivation, and an overall unthrifty appearance (Brown, 2009; Curtis, 2007). Recent research has focused on the development of tall fescue stands that are endophyte-free (E-) or stands that contain a novel endophyte (NE). This lower level is less toxic to cattle grazing tall fescue. The reviewed studies compare cattle performance and stand persistence of E- and NE tall fescue stands to that of E+ tall fescue stands. The purpose of this paper is to review the findings of recent studies to understand the effects of grazing E+ tall fescue compared to E- and NE tall fescue stands on beef cattle productivity.
RESULTS
Animal Performance
The four studies included in this review examined the performance of beef cattle grazing tall fescue with varying levels of endophyte infection. Performance data collected include measurements on body weight gain, serum prolactin levels, pasture utilization, and rectal temperature. The studies also measured differences in performance during grazing between seasonal changes.
Body Weight Gain. The given studies evaluated difference in body weight gain between cattle grazing tall fescue forages with varying endophyte status. Cattle grazing E+ tall fescue stands generally had lowered body weight gains than those of cattle grazing E- and NE tall fescue forages (Drewnoski, 2009). Hopkins stated that during the spring grazing season, cattle grazing E+ tall fescue stands consistently had decreased body weight gains up to half of that from cattle grazing E- or NE tall fescue stands (2006). In a study evaluating the performance of lactating cows and their calves on varying levels of endophyte infection, Curtis found that lactating cows on the low treatment (0% endophyte infection) had less loss of BW and greater BCS than cows on medium (51%) or high (89%) treatments (2007). There were no residual effects on body weight gain in the nursing calves in this study. Beck found that during warm growing seasons for every percent increase in endophyte infection there was a corresponding decrease in ADG by five grams (2008). The general consensus from these studies is that endophyte infection does decrease body weight gain during the warm seasons, but has little to no effect on body weight gain during the late fall to winter season.
Serum Prolactin Levels. Endophyte infection has been correlated with decreased serum prolactin levels in cattle grazing E+ tall fescue stands. Drewnoski found that growing heifers grazing tall fescue stands had depressed levels of prolactin despite lowered levels of ergot alkaloids during the fall and winter seasons (2009). However, Hopkins found that there were no significant differences in prolactin levels for cattle grazing fall stockpiled tall fescue stands (2006). During the spring grazing season when forages are in the growing stages, ergot alkaloid levels are rising and seem to have a greater effect on prolactin levels. Hopkins found that cattle on E+ stands consistently showed lower serum prolactin levels than those grazing E- or NE tall fescue stands (2006).
Rectal Temperatures. Only one study in this review observed measurements of rectal temperatures in cattle grazing different tall fescue stands. These observations showed that rectal temperatures did not vary between treatments during the fall season. However, temperatures observed were elevated in the spring with cattle grazing E+ tall fescue stands corresponding to increased ergot alkaloid concentrations (Hopkins, 2006).
Pasture Utilization. Cattle grazing during the spring season grazed more heavily on E- or NE stands than E+ stands, showing preference for tall fescue stands with lower levels of endophyte infection (Hopkins, 2006). However, during the fall season there seemed to be no difference in pasture utilization between treatments (Curtis, 2007). During the fall grazing season, cattle did not exhibit any differences in DMI between treatments (Drewnoski, 2009; Hopkins, 2006). Hopkins did observe that due to elevated rectal temperatures and increased water consumption during the spring season, cattle did have lower DMI levels on E+ tall fescue stands (2006).
Seasonal Grazing. Overall, the review of these studies finds that cattle perform better with E+ tall fescue stands when grazing stockpiled forage during the late fall and winter season versus grazing these E+ stands during the spring season. Beck showed that cattle grazing E+ tall fescue stands had greater ADG during the fall compared to the spring season (0.62 vs. 0.31, kg, 2008) Gains were lower for cattle grazing E+ than NE, but gains for NE (0.85) did not differ between seasons (Beck, 2008). Beck also found that net returns were greater for cattle grazing NE compared to E+ tall fescue stands (219.09 vs. -170.14, $/ha; 2008).
Tall Fescue Forage
Measurements in forage composition for the four studies included varying levels of wild-type endophyte infection (E+), novel endophyte infection (NE), and endophyte free (E-) tall fescue stands. These studies also evaluated differences in endophyte characteristics during seasonal changes.
Endophyte Levels. Several previous studies have shown that animal performance with varying endophyte status in tall fescue differs. In addition, stand persistence becomes a factor with increase grazing pressure, drought, and harsh environmental conditions. Beck found that E- tall fescue stands had decreased stand persistence and do not tolerate drought or intensive grazing well; resulting in a stand loss within four years (2008). NE tall fescue stands have the attributes of stronger persistence than E+ tall fescue stands without the decrease in animal performance (Beck, 2008). Hopkins found that there is a greater ratio of forage cover to bare soil with E+ tall fescue stands (2006).
Seasonal Changes. Endophyte levels change with the growing seasons. There tends to be greater ergot alkaloid concentrations in tall fescue stands during the spring, summer, and fall growing seasons as compared to levels during the late fall and winter seasons (Drewnoski, 2009; Hopkins, 2006). Drewnoski noted that ergot alkaloid levels dropped as much as 80% during late fall to winter seasons (2009). This would suggest that grazing stockpiled E+ tall fescue stands is most beneficial for animal performance from mid-December thru mid-March (Drewnoski, 2009).
DISCUSSION AND CONCLUSION
This review of recent literature on the topic of endophyte infection of tall fescue stands concludes that endophyte infection levels do affect animal performance. These negative effects are greatly reduced by grazing stockpiled forage during the late fall and winter seasons or by replacing E+ tall fescue stands with either E- or NE tall fescue. Performance of cattle is greater, and health problems can be minimized when grazing stockpiled tall fescue stands in the fall compared to grazing during the spring growing season (Hopkins, 2006). The negative impacts of ergot alkaloids can be avoided by using E- or NE tall fescue stands for grazing and are more beneficial to use in seasons with warmer ambient temperatures (Drewnoski, 2009; Beck, 2008; Hopkins, 2006).
Cattle grazing E+ tall fescue will exhibit decreased performance due to the presence of ergot alkaloids. Effects on cattle performance include reduced body weight gains, decreased serum prolactin levels, increased rectal temperatures, and decreased DMI and pasture utilization. Cattle exhibit these symptoms most during warmer growing seasons with higher ambient temperatures and an increased presence of ergot alkaloids. Effects are not as significant, even negligible, during cool seasons when ambient temperatures are cooler, and there is a decreased presence of ergot alkaloids.
There are a few considerations to make when replacing a native E+ tall fescue stand. E+ tall fescue stands exhibit the greatest stand persistence of the three types of endophyte status. Performance of cattle grazing NE tall fescue is comparable to that on E- tall fescue, and NE takes advantage of the stand persistence from a non-toxic endophyte (Beck, 2008). Beck found that a period of three to seven years is required to recover the costs of replacing an E+ tall fescue stand with a NE tall fescue (2008).
There is value in replacing E+ tall fescue stands with NE tall fescue for grazing during warmer growing seasons; however, animal performance is not greatly impacted by ergot alkaloids when grazing stockpiled tall fescue forages during the late fall and winter seasons. NE tall fescue stands offer greater animal performance, longer growing seasons, and a decreased risk of stand persistence when utilized as a forage source for grazing cattle (Hopkins, 2009). Hopkins recognizes that NE tall fescue stands with greater stand persistence will be needed for successful application in cattle grazing programs. Although, it may be more economical for producers to utilize stockpiled E+ tall fescue forages for late fall and winter grazing to avoid the negative impacts of ergot alkaloids found in the forage.
Literature Cited
Bacon, C.W. 1993. Abiotic stress tolerances (moisture, nutrients) and photosynthesis in endophyte-infected tall fescue. Agric., Ecosystems, and Environ. 44:123-141.
Beck, P.A., S.A. Gunter, K.S. Lusby, C.P. West, K.B. Watkins, and D.S. Hubbell, III. 2008. Animal performance and economic comparison of novel and toxic endophyte tall fescues to cool-season annuals. J. Anim. Sci. 86:2043-2055.
Brown, K.R., G.A. Anderson, K. Son, G. Rentfrow, L.P. Bush, J.L. Klotz, J.R. Strickland, J.A. Boling, and J.C. Matthews. 2009. Growing steers grazing high versus low endophyte (Neotyphodium coenophialum)-infected tall fescue have reduced serum enzymes, increased hepatic glucogenic enzymes, and reduced liver and carcass mass. J. Anim. Sci. 87:748-760.
Curtis, L.E., and R.L. Kallenbach. 2007. Endophyte infection level of tall fescue stockpiled for winter grazing does not alter gain of calves nursing lactating beef cows. J. Anim. Sci. 85:2346-2353.
Drewnoski, M.E., E.J. Oliphant, B.T. Marshall, M.H. Poore, J.T. Green, and M.E. Hockett. 2009. Performance of growing cattle grazing stockpiled Jesup tall fescue with varying endophyte status. J. Anim. Sci. 87:1034-1041.
Hopkins, A.A., and M.W. Alison. 2006. Stand persistence and animal performance for tall fescue endophyte combinations in the south central USA. Agron. J. 98:1221-1226.
Thursday, December 10, 2009
Animal Identification
This is a group paper written over the pros and cons of animal identification. This topic has been a constant controversy between producers with recent legislation proposals in congress. Everyone has their own opinion on the issue, as for me I have mine but I will keep them to myself till later. Enjoy!
Animal Identification
Records show that humans have been using individual animal identification methods for more than 3,800 years. Early records show hot iron branding was used as a means of identification on valuable animals like horses of the Greek, Chinese, and Teutonic nights. As early as the seventeenth century identification was important to disease monitoring by means of ink tattoos. Even as far back as the fourteenth century certificates of safety and origin accompanied animal products during outbreaks of disease. Animal identification, no matter its medium, can be defined as “the combination and linking of the identification and registration of an animal individually, with a unique identifier, or collectively by its epidemiological unit or group, with a unique group identifier” (Bowling, 2008).
Over the centuries, animal identification has used several mediums. Animal identification began in the United States with cattle ranchers during the late 1800’s and early 1900’s. Ranchers often used hot iron branding to indicate ownership. Beginning in the 1960’s, government agencies began using other methods to monitor movements and diseases. These mediums include ear tags, back tags, tattoos, and face brands. Recent methods of identification remain the same with some additional mediums; neck chains, tail tags, freeze brands, paint marks, and leg brands (APHIS, 2009a). One of the most pressing introductions to animal identification is electronic mediums, including injectable transponders, ear tags, and internal boluses (Rossing, 1999). These electronic identifications are changing the scope of animal identification in the 21st century. Despite the changes in types of identification mediums, the reasons for livestock identification remain the same: disease control, bio-security protection, identification for vaccinations and tests in disease eradication programs, official identification in commerce, identification of blood and tissue specimens, improvement of laboratory capabilities, health status certification, risk assessment, promoting marketability, and monitoring animal movement (APHIS, 2009a).
Virtually all livestock species and sectors of livestock industries use some sort of animal identification. Owners of livestock, both large and small operations, use identification methods for information management. Marketing agents use identification to track animals into and out of their possession. Animal breeders and breed associations, to track lineage and genetic information within breeds, use animal identification extensively. Industry feeders and finishers use lot identifications to track feed information, health records, and marketing information for cattle, hogs, and poultry. Harvesting and processing facilities use group identification to record marketing information for the industry and for the USDA records. Surprisingly, with all of these sectors using identification, there is no uniform system used within individual species.
Individual animal identification has taken front stage in the United States livestock industry with the introduction of the National Animal Identification System (NAIS). The objective of NAIS is to have the ability to trace an animal or a group of animals to their source within forty-eight hours in the event of a disease outbreak. The ultimate goal of the program is to be able to track all premises and all animals that may have had contact with the affected animal (Gray, 2004). Components of the NAIS program include producer registration for premises identification numbers (PIN) and animal identification numbers (AIN). A set requirement for animal identification has not been established for the program. The Country of Origin Labeling (COOL) provision from the 2002 Farm Bill is a program that will likely be complementary to NAIS. This program requires country of origin labeling of animal and food products. The aim of this program is aide in assurance of food safety and consumer information (Umberger, 2004). COOL became mandatory for processors and includes certain products effective September 30, 2008, although NAIS has not become a mandatory program for producers as of late.
There are also current regulations and identification systems within the livestock industries. Brucellosis in cattle has caused the industry to take actions in identifying animals with this disease and tracing them back to their owners in order to test the entire herd. Market Cattle Identification (MCI) is a system in which back tags are placed on the shoulders of all cattle and bison 2 years of age or older that are being marketed. Blood samples are taken and tested for brucellosis. If the animal tests positive for brucellosis, the back tag number traces it back to the herd of origin and the herd owner is then contacted by a State or Federal animal health official and the herd is tested. This system of identification is effective in locating infected herds and preventing the spread of this disease. However, this system does not suffice for an overall effective identification system because it is only limited to adult breeding animals that are being marketed (APHIS, 2007).
Within the swine industry, PIC Traq is one of the leading genetic databases, where individual swine identification is the primary incentive. PIC Traq is utilized to identify individual performance including carcass and meat quality characteristics, genetic markers, and commercial performance (PIC TRAQ, 2009). Data are collected daily through genetic nuclei from multiplier farms on every continent and are downloaded to a primary database. From statistical methodology or a program called BLUP (Best Linear Unbiased Prediction), PIC individuals can calculate EBV’s (Estimated Breeding Values), which in turn benefit genetic nuclei to increase genetic improvement within their sow herds. Electronically PIC Traq uses advanced technology benefits in extreme to identify optimal mating selections, quality AI semen collection, minimization of line breeding, and optimize genetic markers in each individual hog. Additionally, foreign markets and international trades are opened due to the advancement of the farrow to finish identification concept, which gives a history of the animal from producer to consumer. This history background of the animal identifies what the animal was fed, when and where vaccinations where given, and how and where the animal was housed. (PIC TRAQ, 2009)
The National Animal Identification System (NAIS) has many beneficial aspects and will affect structural changes in many livestock industries. However, the exact extent will not be certain until final plans are made to implement the program and the participation of the program is determined. Nevertheless, the effects of the NAIS on the market structure are great in areas of seedstock producers, stocker operations, and feeding operations. Seedstock producers will have the most beneficial gain from the identification system. The improved traceability and assurance provided by this system could help to strengthen the value of genetic lines that consumers are willing to pay extra to acquire. Stocker operations will benefit from the identification system once it has been in place for a period by lowering the costs of tagging cattle (Mark, 2004).
Along with market structural changes, a national animal identification system will encourage communication across all sectors of the livestock industries. A controlled animal identification system will enhance the efficacy of traceability of livestock during events that require shared information, such as an occurrence of a disease outbreak. Information about animal origins, movements, transfer of ownership, and health records must be accessible quickly. This will require a uniform identification method within each species and enhance communication among producers. This increased level of communication will lead to sharing of management practices, treatment methods, and marketing options. Sharing information will require government interaction with producers that will increase effectiveness of government policies that affect livestock industries. This increased communication among industry sectors will eventually benefit the efficiency of the livestock industry. Together these preceding issues show the positive aspects of a controlled animal identification system.
A controlled animal identification system would bring along negative impacts to the industries. Producers would face massive challenges if forced to implement animal identification in the cattle and sheep industries in western production systems. The topographical and geographical changes pose a big threat to a controlled identification system. With the changes in terrain in common grazing grounds, comes high installation and monitoring costs for boundary fences. Estimated costs to build a fence in mountain ranges of the west is close to $9,000 per mile compared to only $3,500 per mile in the southeastern part of the country. There is increased transmission of disease among livestock herds in these areas, not only from comingling herds from lack of boundary fences, but also from wild elk, horse, and cattle migration. There is frequent movement of livestock herds in this region. Between seasonal grazing grounds, herds may move 4,000 feet in elevation and several miles to forage supplies. Weather changes, such as drought, cause movement of herds from one ranch location to other locations that may be as far as 100 miles. Cooperative grazing practices are also common in western regions. These grazing co-ops often involve several members who commingle their herds for summer grazing periods. If enforced controlled identification in these systems must include provisions for multiple premise IDs per animal, multiple owners per animal, and multiple owners per premise. Because of the movement of these animals, “isolating disease outbreaks could become quite complex for some areas of the west” (Tronstad, 2004).
Another major concern with the National Animal Identification System is the cost and how it will affect the producers of all species. Cattle producers will suffer the greatest from the incorporation of this system. This identification system requires the purchasing of not only the ear tags, but also the technology that comes with it such as the panels and wand electronic readers as well as computers and software. At this point and time, the premise identification number registration is free; however, there is a possibility of costs that are related to time, mileage, and paperwork requirements. This possible fee could be a total up to $20 to register, yet many producers will need to renew their registration information as their operations change, which will increase the costs. (APHIS, 2009b) In every species there will have to be a different type of identification system implemented due to the diverse ways livestock are marketed.
The Nebraska Department of Agriculture (1992) implemented laws that take precautionary actions against swine brucellosis. One of the steps under this law requires that all animals be tested for this disease and upon testing animals need identification of some manner. Identifications for this test can include indication by ear notch, tattoos, or ear tags. The Nebraska Bureau suggests using ear tags. This identification system is beneficial in identifying which animals have been tested for this particular disease; however, this disease does not have any type of precautionary vaccination. So therefore, the mandatory identification system is not completely beneficial, nor cost efficient. With different types of identification systems present, there is no way to utilize this identification system effectively.
Program participation will be difficult for a controlled animal identification system. American ranchers tend to have a sense on independence from government agencies in how they manage their operations (Tronstad, 2004). Many producers are reluctant to participate in mandatory programs unless there is an obvious, direct guaranteed benefit for participation. “Participation in active disease programs has decreased as diseases have been eradicated” (USDA, 2007). For example, the cattle brucellosis eradication program requires that cattle be vaccinated and tagged with an official program tag and the information about these cattle be recorded. Because the disease is becoming less common and as more states become classified as brucellosis-free, annually less than 12% of cattle are vaccinated for brucellosis (USDA, 2007). A controlled animal identification system must include producer incentives to maintain participation in the program.
In the beef and dairy cattle industry, traceability can be difficult due to the widespread diversification and different sectors of the marketing chain. (USDA, 2007) Although, this can be argued as a reason to incorporate a national identification system, the costs outweigh the benefits in this situation. The costs estimated for RFID tags range from $2.00 to $2.60 per tag. (APHIS, 2009b) As stated earlier, other technologies will need to be purchased, also, facilities must be established in order to work these animals. Producers that already have tagging implemented in their programs will have fewer costs when it comes to facilities and labor. Many small producers (1-49 head of cattle) will be paying more for the RFID than larger producers will (5,000 head plus). This will greatly affect these small producers and possibly put them out of business. The information shown in Table 1 is the breakdown of the costs in the cattle industry for 100% participation (APHIS, 2009).
In the swine industry, costs are much lower for the identification system. Majority of swine move through the production chain as a group and are identified using a group identification number. This reduces the cost of ear tagging in swine. In addition, electronic reading will not be required in swine due to visual tag usage; however, there are still costs with reading and recording data. The information shown in Table 2 explains the cost of a national identification system for swine with 100% participation (APHIS, 2009b).
Sheep producers already have an identification system implemented due to the scrapie programs. This allows a high degree of traceability in the sheep industry. (USDA, 2007) The costs associated with a national identification system are for the reading and recording of tag information. The total cost would total $3,663,961 (APHIS, 2009b).
The poultry industry would have the least amount of cost when it comes to tagging; however, there are still costs with recording, reporting, and sorting data. With 100% participation from the producers, the total cost would total $9,112,856.
The horse industry will be even more complex in terms of longer life spans, higher values, and more frequent movement. (APHIS, 2009b) When in other species ear tags are used, the injection of microchips in horses will greatly increase the cost of implementing this system in the equine industry. The information shown in Table 3 explains the costs associated with identifying horses with microchips (APHIS, 2009b).
The costs associated with the implementation of large animal identification systems will force small operations to sell-out due to large industrial operations meeting consumer demands by identification systems more efficiently while gaining the premiums. This in turn leaves small operations with the ability to not feasibly turn a profit, and in conclusion will be required to shut down their operations.
A controlled animal identification system has its positive and negative aspects on livestock industries. Different methods of animal identification have existed for centuries, although the mediums used for identification have changed. In progressing livestock industries that are receiving more pressure for production information, producers and industry members can find reasons to support and argue against government regulated animal identification.
Literature Cited
APHIS. 2007. Questions and answers about brucellosis. http://www.aphis.usda.gov/ publications/animal_health/content/printable_version/faq_brucellosis.pdf Accessed Sept. 15, 2009.
APHIS. 2009a. Animal identification information. http://www.aphis.usda.gov/animal_health /animal_diseases/animal_id/ Accessed Aug. 16, 2009.
APHIS. 2009b. Overview report of the benefit-cost analysis of the National Animal Identification System.
Bowling, M.B., D.L. Pendell, D.L. Morris, Y. Yoon, K. Katoh, K.E. Belk and G.C. Smith. 2008. Identification and traceability of cattle in selected countries outside of North America. The Professional Animal Scientist. 24:287-294.
Farmers Legal Action Group Inc. 2009. The country of origin labeling program: a snapshot of how the program affects farmers. http://www.flaginc.org/topics/pubs/arts/ COOL_FactSheet20090423.pdf Accessed Oct. 19, 2009.
Gray, C.W. January 2004. The national animal identification system: basics, blueprint, timelines, and processes. Western Extension Marketing Committee. WEMC FS#1-04.
Nebraska Department of Agriculture.1992. Nebraska swine brucellosis act. http://www.agr.state.ne.us/ regulate/bai/actaj.htm Accessed Oct. 19, 2009.
Mark, D.R. 2004. Effects of animal identification on cattle market structure. Western Extension Marketing Committee. WEMC FS# 9-04.
PIC Traq. 2009. PIC. www.Pic.com/cms/usa/797.htm Accessed Oct. 19, 2009.
Rossing, W. 1999. Animal identification: Introduction and history. Computers and Electronics in Agriculture. 24:1-4.
Tronstad, R. October 2004. Challenges of animal identification in the West. Western Extension Marketing Committee. WEMC FS#10-04.
Umberger, W.J. April 2004. Animal Identification: The National Animal Identification System and Country-of-Origin Labeling: How are they related. Colorado State University Cooperative Extension Service. Western Extension Marketing Committee. WEMC FS#4-04.
USDA. 2007. Advancing animal disease traceability overview synopsis. http://animalid.aphis.usda.gov/nais/naislibrary/documents/plans_reports/traceability_overview.pdf Accessed Sept. 15, 2009.
USDA. 2007. The facts about traceability National animal ID system. http://animalid.aphis. usda.gov/nais/naislibrary/documents/factsheets_brochures/TraceabilityFactsheet.pdf Accessed Sept. 15, 2009.
USDA. 2008. Animal identification. http://animalid.aphis.usda.gov/nais/audience/vets/printable /animal_identification.pdf Accessed Sept. 15, 2009.
Ward, S. Mar. 13, 2008. Wisconsin leads the way in identification. http://www.agriview .com/articles/2008/03/17/livestock_news/livestock01.txt Accessed Aug. 16, 2009.
Animal Identification
Records show that humans have been using individual animal identification methods for more than 3,800 years. Early records show hot iron branding was used as a means of identification on valuable animals like horses of the Greek, Chinese, and Teutonic nights. As early as the seventeenth century identification was important to disease monitoring by means of ink tattoos. Even as far back as the fourteenth century certificates of safety and origin accompanied animal products during outbreaks of disease. Animal identification, no matter its medium, can be defined as “the combination and linking of the identification and registration of an animal individually, with a unique identifier, or collectively by its epidemiological unit or group, with a unique group identifier” (Bowling, 2008).
Over the centuries, animal identification has used several mediums. Animal identification began in the United States with cattle ranchers during the late 1800’s and early 1900’s. Ranchers often used hot iron branding to indicate ownership. Beginning in the 1960’s, government agencies began using other methods to monitor movements and diseases. These mediums include ear tags, back tags, tattoos, and face brands. Recent methods of identification remain the same with some additional mediums; neck chains, tail tags, freeze brands, paint marks, and leg brands (APHIS, 2009a). One of the most pressing introductions to animal identification is electronic mediums, including injectable transponders, ear tags, and internal boluses (Rossing, 1999). These electronic identifications are changing the scope of animal identification in the 21st century. Despite the changes in types of identification mediums, the reasons for livestock identification remain the same: disease control, bio-security protection, identification for vaccinations and tests in disease eradication programs, official identification in commerce, identification of blood and tissue specimens, improvement of laboratory capabilities, health status certification, risk assessment, promoting marketability, and monitoring animal movement (APHIS, 2009a).
Virtually all livestock species and sectors of livestock industries use some sort of animal identification. Owners of livestock, both large and small operations, use identification methods for information management. Marketing agents use identification to track animals into and out of their possession. Animal breeders and breed associations, to track lineage and genetic information within breeds, use animal identification extensively. Industry feeders and finishers use lot identifications to track feed information, health records, and marketing information for cattle, hogs, and poultry. Harvesting and processing facilities use group identification to record marketing information for the industry and for the USDA records. Surprisingly, with all of these sectors using identification, there is no uniform system used within individual species.
Individual animal identification has taken front stage in the United States livestock industry with the introduction of the National Animal Identification System (NAIS). The objective of NAIS is to have the ability to trace an animal or a group of animals to their source within forty-eight hours in the event of a disease outbreak. The ultimate goal of the program is to be able to track all premises and all animals that may have had contact with the affected animal (Gray, 2004). Components of the NAIS program include producer registration for premises identification numbers (PIN) and animal identification numbers (AIN). A set requirement for animal identification has not been established for the program. The Country of Origin Labeling (COOL) provision from the 2002 Farm Bill is a program that will likely be complementary to NAIS. This program requires country of origin labeling of animal and food products. The aim of this program is aide in assurance of food safety and consumer information (Umberger, 2004). COOL became mandatory for processors and includes certain products effective September 30, 2008, although NAIS has not become a mandatory program for producers as of late.
There are also current regulations and identification systems within the livestock industries. Brucellosis in cattle has caused the industry to take actions in identifying animals with this disease and tracing them back to their owners in order to test the entire herd. Market Cattle Identification (MCI) is a system in which back tags are placed on the shoulders of all cattle and bison 2 years of age or older that are being marketed. Blood samples are taken and tested for brucellosis. If the animal tests positive for brucellosis, the back tag number traces it back to the herd of origin and the herd owner is then contacted by a State or Federal animal health official and the herd is tested. This system of identification is effective in locating infected herds and preventing the spread of this disease. However, this system does not suffice for an overall effective identification system because it is only limited to adult breeding animals that are being marketed (APHIS, 2007).
Within the swine industry, PIC Traq is one of the leading genetic databases, where individual swine identification is the primary incentive. PIC Traq is utilized to identify individual performance including carcass and meat quality characteristics, genetic markers, and commercial performance (PIC TRAQ, 2009). Data are collected daily through genetic nuclei from multiplier farms on every continent and are downloaded to a primary database. From statistical methodology or a program called BLUP (Best Linear Unbiased Prediction), PIC individuals can calculate EBV’s (Estimated Breeding Values), which in turn benefit genetic nuclei to increase genetic improvement within their sow herds. Electronically PIC Traq uses advanced technology benefits in extreme to identify optimal mating selections, quality AI semen collection, minimization of line breeding, and optimize genetic markers in each individual hog. Additionally, foreign markets and international trades are opened due to the advancement of the farrow to finish identification concept, which gives a history of the animal from producer to consumer. This history background of the animal identifies what the animal was fed, when and where vaccinations where given, and how and where the animal was housed. (PIC TRAQ, 2009)
The National Animal Identification System (NAIS) has many beneficial aspects and will affect structural changes in many livestock industries. However, the exact extent will not be certain until final plans are made to implement the program and the participation of the program is determined. Nevertheless, the effects of the NAIS on the market structure are great in areas of seedstock producers, stocker operations, and feeding operations. Seedstock producers will have the most beneficial gain from the identification system. The improved traceability and assurance provided by this system could help to strengthen the value of genetic lines that consumers are willing to pay extra to acquire. Stocker operations will benefit from the identification system once it has been in place for a period by lowering the costs of tagging cattle (Mark, 2004).
Along with market structural changes, a national animal identification system will encourage communication across all sectors of the livestock industries. A controlled animal identification system will enhance the efficacy of traceability of livestock during events that require shared information, such as an occurrence of a disease outbreak. Information about animal origins, movements, transfer of ownership, and health records must be accessible quickly. This will require a uniform identification method within each species and enhance communication among producers. This increased level of communication will lead to sharing of management practices, treatment methods, and marketing options. Sharing information will require government interaction with producers that will increase effectiveness of government policies that affect livestock industries. This increased communication among industry sectors will eventually benefit the efficiency of the livestock industry. Together these preceding issues show the positive aspects of a controlled animal identification system.
A controlled animal identification system would bring along negative impacts to the industries. Producers would face massive challenges if forced to implement animal identification in the cattle and sheep industries in western production systems. The topographical and geographical changes pose a big threat to a controlled identification system. With the changes in terrain in common grazing grounds, comes high installation and monitoring costs for boundary fences. Estimated costs to build a fence in mountain ranges of the west is close to $9,000 per mile compared to only $3,500 per mile in the southeastern part of the country. There is increased transmission of disease among livestock herds in these areas, not only from comingling herds from lack of boundary fences, but also from wild elk, horse, and cattle migration. There is frequent movement of livestock herds in this region. Between seasonal grazing grounds, herds may move 4,000 feet in elevation and several miles to forage supplies. Weather changes, such as drought, cause movement of herds from one ranch location to other locations that may be as far as 100 miles. Cooperative grazing practices are also common in western regions. These grazing co-ops often involve several members who commingle their herds for summer grazing periods. If enforced controlled identification in these systems must include provisions for multiple premise IDs per animal, multiple owners per animal, and multiple owners per premise. Because of the movement of these animals, “isolating disease outbreaks could become quite complex for some areas of the west” (Tronstad, 2004).
Another major concern with the National Animal Identification System is the cost and how it will affect the producers of all species. Cattle producers will suffer the greatest from the incorporation of this system. This identification system requires the purchasing of not only the ear tags, but also the technology that comes with it such as the panels and wand electronic readers as well as computers and software. At this point and time, the premise identification number registration is free; however, there is a possibility of costs that are related to time, mileage, and paperwork requirements. This possible fee could be a total up to $20 to register, yet many producers will need to renew their registration information as their operations change, which will increase the costs. (APHIS, 2009b) In every species there will have to be a different type of identification system implemented due to the diverse ways livestock are marketed.
The Nebraska Department of Agriculture (1992) implemented laws that take precautionary actions against swine brucellosis. One of the steps under this law requires that all animals be tested for this disease and upon testing animals need identification of some manner. Identifications for this test can include indication by ear notch, tattoos, or ear tags. The Nebraska Bureau suggests using ear tags. This identification system is beneficial in identifying which animals have been tested for this particular disease; however, this disease does not have any type of precautionary vaccination. So therefore, the mandatory identification system is not completely beneficial, nor cost efficient. With different types of identification systems present, there is no way to utilize this identification system effectively.
Program participation will be difficult for a controlled animal identification system. American ranchers tend to have a sense on independence from government agencies in how they manage their operations (Tronstad, 2004). Many producers are reluctant to participate in mandatory programs unless there is an obvious, direct guaranteed benefit for participation. “Participation in active disease programs has decreased as diseases have been eradicated” (USDA, 2007). For example, the cattle brucellosis eradication program requires that cattle be vaccinated and tagged with an official program tag and the information about these cattle be recorded. Because the disease is becoming less common and as more states become classified as brucellosis-free, annually less than 12% of cattle are vaccinated for brucellosis (USDA, 2007). A controlled animal identification system must include producer incentives to maintain participation in the program.
In the beef and dairy cattle industry, traceability can be difficult due to the widespread diversification and different sectors of the marketing chain. (USDA, 2007) Although, this can be argued as a reason to incorporate a national identification system, the costs outweigh the benefits in this situation. The costs estimated for RFID tags range from $2.00 to $2.60 per tag. (APHIS, 2009b) As stated earlier, other technologies will need to be purchased, also, facilities must be established in order to work these animals. Producers that already have tagging implemented in their programs will have fewer costs when it comes to facilities and labor. Many small producers (1-49 head of cattle) will be paying more for the RFID than larger producers will (5,000 head plus). This will greatly affect these small producers and possibly put them out of business. The information shown in Table 1 is the breakdown of the costs in the cattle industry for 100% participation (APHIS, 2009).
In the swine industry, costs are much lower for the identification system. Majority of swine move through the production chain as a group and are identified using a group identification number. This reduces the cost of ear tagging in swine. In addition, electronic reading will not be required in swine due to visual tag usage; however, there are still costs with reading and recording data. The information shown in Table 2 explains the cost of a national identification system for swine with 100% participation (APHIS, 2009b).
Sheep producers already have an identification system implemented due to the scrapie programs. This allows a high degree of traceability in the sheep industry. (USDA, 2007) The costs associated with a national identification system are for the reading and recording of tag information. The total cost would total $3,663,961 (APHIS, 2009b).
The poultry industry would have the least amount of cost when it comes to tagging; however, there are still costs with recording, reporting, and sorting data. With 100% participation from the producers, the total cost would total $9,112,856.
The horse industry will be even more complex in terms of longer life spans, higher values, and more frequent movement. (APHIS, 2009b) When in other species ear tags are used, the injection of microchips in horses will greatly increase the cost of implementing this system in the equine industry. The information shown in Table 3 explains the costs associated with identifying horses with microchips (APHIS, 2009b).
The costs associated with the implementation of large animal identification systems will force small operations to sell-out due to large industrial operations meeting consumer demands by identification systems more efficiently while gaining the premiums. This in turn leaves small operations with the ability to not feasibly turn a profit, and in conclusion will be required to shut down their operations.
A controlled animal identification system has its positive and negative aspects on livestock industries. Different methods of animal identification have existed for centuries, although the mediums used for identification have changed. In progressing livestock industries that are receiving more pressure for production information, producers and industry members can find reasons to support and argue against government regulated animal identification.
Literature Cited
APHIS. 2007. Questions and answers about brucellosis. http://www.aphis.usda.gov/ publications/animal_health/content/printable_version/faq_brucellosis.pdf Accessed Sept. 15, 2009.
APHIS. 2009a. Animal identification information. http://www.aphis.usda.gov/animal_health /animal_diseases/animal_id/ Accessed Aug. 16, 2009.
APHIS. 2009b. Overview report of the benefit-cost analysis of the National Animal Identification System.
Bowling, M.B., D.L. Pendell, D.L. Morris, Y. Yoon, K. Katoh, K.E. Belk and G.C. Smith. 2008. Identification and traceability of cattle in selected countries outside of North America. The Professional Animal Scientist. 24:287-294.
Farmers Legal Action Group Inc. 2009. The country of origin labeling program: a snapshot of how the program affects farmers. http://www.flaginc.org/topics/pubs/arts/ COOL_FactSheet20090423.pdf Accessed Oct. 19, 2009.
Gray, C.W. January 2004. The national animal identification system: basics, blueprint, timelines, and processes. Western Extension Marketing Committee. WEMC FS#1-04.
Nebraska Department of Agriculture.1992. Nebraska swine brucellosis act. http://www.agr.state.ne.us/ regulate/bai/actaj.htm Accessed Oct. 19, 2009.
Mark, D.R. 2004. Effects of animal identification on cattle market structure. Western Extension Marketing Committee. WEMC FS# 9-04.
PIC Traq. 2009. PIC. www.Pic.com/cms/usa/797.htm Accessed Oct. 19, 2009.
Rossing, W. 1999. Animal identification: Introduction and history. Computers and Electronics in Agriculture. 24:1-4.
Tronstad, R. October 2004. Challenges of animal identification in the West. Western Extension Marketing Committee. WEMC FS#10-04.
Umberger, W.J. April 2004. Animal Identification: The National Animal Identification System and Country-of-Origin Labeling: How are they related. Colorado State University Cooperative Extension Service. Western Extension Marketing Committee. WEMC FS#4-04.
USDA. 2007. Advancing animal disease traceability overview synopsis. http://animalid.aphis.usda.gov/nais/naislibrary/documents/plans_reports/traceability_overview.pdf Accessed Sept. 15, 2009.
USDA. 2007. The facts about traceability National animal ID system. http://animalid.aphis. usda.gov/nais/naislibrary/documents/factsheets_brochures/TraceabilityFactsheet.pdf Accessed Sept. 15, 2009.
USDA. 2008. Animal identification. http://animalid.aphis.usda.gov/nais/audience/vets/printable /animal_identification.pdf Accessed Sept. 15, 2009.
Ward, S. Mar. 13, 2008. Wisconsin leads the way in identification. http://www.agriview .com/articles/2008/03/17/livestock_news/livestock01.txt Accessed Aug. 16, 2009.
Prevention and Treatment for Bovine Respiratory Disease in High Risk, Newly Received Stocker Calves
This is a paper written for one of my classes this semester covering the advantages of using MLV treatments for BRD in stocker calves. I learned a lot by writing this, hope you will too. Enjoy!
Prevention and Treatment for Bovine Respiratory Disease in High Risk, Newly Received Stocker Calves
Bovine Respiratory Disease (BRD) is one of the leading causes of morbidity and mortality in stocker and feedlot operations. Cattle in these operations are highly susceptible to contracting the disease and are classified as high or low risk based on a number of factors; “commingling with other animals, transportation stress, immune status, nutritional condition, environment conditions, and the skill level of management to diagnose cattle displaying symptoms of BRD” (Richeson, 2008). Cattle entering stocker and/or feedlot operations are normally classified as high risk if originating from livestock auctions for reasons including “unknown origin, commingling with numerous other animals, and being recently weaned from small cow-calf operations that seldom use vaccination or other BRD prevention strategies” (Richeson, 2009). Because the number of cattle classified as high risk is relatively high in the stocker and feedlot industry, it is important to find the most effective methods of prevention and treatment for BRD. Although there have been many research trials conducted showing the impact of BRD on cattle, this focus of this paper will be on the methods of prevention and treatment for BRD including 14-day delayed modified live virus vaccination and the efficacy of treatment with different medications.
BRD does have a major impact on health, efficiency, and performance of stocker and feeder calves. According to research from Snowder et al. (2006), BRD has a large impact on both stocker and feeder calves, with 13% and 17%, respectively, of calves being affected by the disease. Snowder’s research shows results of an average economic loss of $15.57 per sick animal. This figure only includes treatment costs and losses from decreased average daily gain (ADG). Similar research conducted by Brooks et al. (2009) shows that BRD has a major effect of costs associated with production. Cattle in this research trial had a decreased ADG of two and a half pounds per day, increased treatment costs of thirty-five dollars per head, and decreased net returns of one hundred fourteen dollars per head, compared to cattle not affected by BRD. These figures show a decrease in economic gains and performance of cattle diagnosed with BRD.
Stress levels at time of initial vaccination can influence the efficacy of modified live virus (MLV) vaccines and health and performance of newly received stocker calves. Richeson et al. (2008) conducted research to evaluate the health, performance, and serum infectious bovine rhinotracheitis (IBR) titers in newly received calves. In this research, stocker calves were tested in two treatments; on arrival vaccination with a MLV vaccine (AMLV) or 14-day delayed MLV vaccination (DMLV). The cattle on the delayed treatment performed better than AMLV cattle with increased body weight (BW) on days fourteen and forty-two (212.7 vs. 208.6kg, p=0.007; 228.1 vs. 224.4kg, p=0.07 (approaching significance), respectively) and greater ADG in periods day-0 thru day-14 and day-0 thru day-42 (1.16 vs. 0.88kg/day, p=0.007; 0.75 vs. 0.65kg/day, p=0.05, respectively). Measurements for effect of vaccination timing on morbidity, mortality, and treatment cost suggest no advantage between the two treatments (AMLV vs. DMLV). Factors involved in these measurements include rectal temperature on day-0 (39.6 vs. 39.6°C, p=0.83), initial BRD treatment (71.5 vs. 63.5%, p=0.12), retreat BRD treatment (25.1 vs. 30.8%, p=0.17), days to first treatment (7.2 vs. 7.7, p=0.72), death loss (2.3 vs. 0.8%, p<0.16), and BRD treatment cost (9.00 vs. $8.75, p=0.76). Morbidity rates were high for both treatments in the trial and did not differ (71.5 vs. 63.5%, p=0.12). Ninety three percent of the BRD cases occurred during the first fourteen days of the trial, suggesting there is no advantage to AMLV treatment to reduce morbidity rates.
Seroconversion rates for IBR titers were measured in the study from Richeson et al. (2008). These measurements show substantially greater amounts of IBR antibodies in the blood system of the calves in the DMLV treatment on day-28 and day-42 after initial vaccination as well as at the end of the trial (p=0.03, p=0.01, p=0.01, respectively). These data suggest an increased vaccine efficacy, likely due to lower stress levels at time of initial vaccination. Later research from Richeson et al. (2009) shows different results. Initially greater (p<0.01) titer levels were present in calves with on-arrival vaccination, but total white blood cell counts were greater for the delayed treatment group. Collectively, the data from these studies suggest an economic advantage to delaying initial MLV vaccination until fourteen days after receiving to improve body weight, average daily gain, and vaccine efficacy.
Research conducted by Wildman et al. (2008) has shown that the type of vaccination given to cattle has an impact on response and number of cases for BRD. In this study, cattle were given MLV vaccines with one or two types of bovine viral diarrhea (BVD) virus. The vaccine type had an effect on the treatment for BRD (p<0.001), mortality rate (p=0.002), and ADG (p=0.008). The rate of BRD cases correlated with the number of yield grade three carcasses, suggesting an economic loss for cattle affected by BRD through the entire cycle, from weaning to harvest. This study enforced the findings of Richeson et al. (2008, 2009) that there is an economic advantage to a well-managed vaccination program as a means of prevention of BRD.
There are several products on the market for treatment of BRD including tilmicosin phosphate (Micotil, Elanco Animal Health), tulathromycin (Draxxin, Pfizer Animal Health), florfenicol (Nuflor, Schering-Plough Animal Health), and enroflaxacin (Baytril, Bayer Animal Health). Use of these medications is for treatment in cases of BRD sickness and mass treatment in high risk newly received calves. Gaylean et al. (1995) conducted a study on the use of tilmicosin phosphate as an arrival medication for mass treatment. Three trials were included in this study to test the effectiveness of tilmicosin phosphate. Trial one involved calves given Micotil on-arrival as a mass treatment and calves were fed a receiving supplement for the duration of the study. Weight gains were greater (p<0.10) for calves receiving on-arrival mass medication than control calves during the first half of the trial but did not differ (p=0.17) over the 28-day period. Dry matter intake (p<0.22) and feed to gain ratio (p<0.81) did not differ between treatments. 46.4% of the control calves were treated for BRD, but none of the mass treatment calves was treated for BRD. The second trial involved mass treatment calves grazing winter wheat pasture. BW and ADG did not differ (p<0.51, p=0.06) between treatments. There was fewer (12.1%) mass control calves treated for BRD than control calves (32.8%). Trial three in this study included three treatments: control, mass treatment with Micotil, and treatment with Micotil when body temperature was greater than 39.7°C (104°F). Calves in this trial were fed a 65% concentrate diet. Calves in this trial receiving Micotil, both mass treatment and treatment by temperature, gained more than control calves (p<0.01). Dry matter intake and feed to gain ratio were lower for calves in the medicated groups than control (p<0.09, p<0.03). No differences were shown between medicated groups. This study has shown that Micotil is highly effective as a mass treatment to increase gains and dry matter intakes. Treated calves had a lower rate of treatment for BRD symptoms. The third trial in this study showed that treatment with Micotil based on body temperature was as effective as mass treatment and reduced the number of calves treated; lowering arrival medication costs.
Studies have been conducted to evaluate the effectiveness of Draxxin. Nutsch et al. (2005), Skogerboe et al. (2005), and Rooney et al. (2005) have all shown that Draxxin is more effective as a treatment than Nuflor or Micotil. Nutsch’s and Skogerboe’s studies resulted in greater weight and performance, and lower retreatment and chronic rates in treatments using Draxxin over Nuflor or Micotil. Rooney’s study showed that when used as a mass treatment, Draxxin decreases morbidity rates and performance of cattle. Collectively these studies show the advantage of Draxxin over other drugs for the treatment and prevention of BRD in newly received stocker calves.
BRD is a major factor in the performance of newly received beef calves in the stocker industry with 13% and 17% of stocker and feeder calves being affected (Snowder, 2006). Cattle affected by BRD often have lower performance with decreased body weights, average daily gains, feed to gain ratios, and dry matter intakes. Morbidity and mortality rates increase cost of gain and decrease net returns for producers by up to $114 per head (Brooks, 2009), making it important to find the most effective means of treatment and prevention for BRD. Richeson et al. (2008, 2009) and Wildman et al. (2008) have shown that delaying treatment with MLV vaccinations by 14 days will increase performance and gains of cattle, increase days to first treatment, as well as decrease morbidity, mortality, and chronic rates and treatment costs in stocker cattle. Vaccine efficacy and calves’ immune response to MLV vaccines is greater when MLV treatment is delayed by 14 days. Several studies have shown that mass medication by Micotil or Draxxin are effective as a means of mass treatment to prevent BRD and reduce the number of retreats and chronics in stocker calves Richeson, 2008; Nutsch 2005).
In conclusion, every situation is different depending on environment and diseases present in the animal herd, so treatment efficacy may differ between operations. Research has shown that delaying MLV vaccination treatment by 14-days combined with mass treatment or treatment by temperature with tilmicosin phosphate or tulathromycin will increase performance and returns in newly received stocker calves at high risk for bovine respiratory disease. With this information, producers will be able to make more informed decisions when creating vaccination and treatment protocols.
Literature Cited
Brooks, K., K.C. Raper, C.E. Ward, B.P. Holland, and C. Krehbiel. 2009. Economic effects of bovine respiratory disease on feedlot cattle during backgrounding and finishing phases. Southern Agricultural Economics Association Annual Meeting.
Galyean, M.L., S.A. Gunter, and K.J. Malcolm-Callis. 1995. Effects of arrival medication with tilmicosin phosphate on health and performance of newly received beef cattle. Journal of Animal Science. 73:1219-1226.
Nutsch, R.G., T.L. Skogerboe, K.A. Rooney, D.J. Weigel, K. Gajewski, and K.F. Lechtenberg. January 2005. Comparative efficacy of tulathromycin, tilmicosin, and florfenicol in the treatment of bovine respiratory disease in stocker cattle. Veterinary Therapeutics. 6:167-179.
Richeson, J.T., E.B. Kegley, M.S. Gadberry, P.A. Beck, J.G. Powell, and C.A. Jones. July 2009. Effects of on-arrival versus delayed clostridial or modified live respiratory vaccinations on health, performance, bovine viral diarrhea virus type I titers, and stress and immune measures of newly received beef calves. Journal of Animal Science. 87:2409-2418.
Richeson, J.T., P.A. Beck, M.S. Gadberry, S.A. Gunter, T.W. Hess, D.S. Hubbell, III, and C. Jones. 2008. Effects of on-arrival versus delayed modified live virus vaccination on health, performance, and serum infectious bovine rhinotracheitis titers of newly received beef calves. Journal of Animal Science. 86:999-1005.
Rooney, K.A., R.G. Nutsch, T.L. Skogerboe, D.J. Weigel, K. Gajewski, and W.R. Kilgore. January 2005. Efficacy of tulathromycin compared with tilmicosin and florfenicol for the control of repiratory disease in cattle at high risk of developing bovine respiratory disease. Veterinary Therapeutics. 6:154-166.
Skogerboe, T.L., K.A. Rooney, R.G. Nutsch, D.J. Weigel, K. Gajewski, and W.R. Kilgore. January 2005. Comparative efficacy of tulathromycin versus florfenicol and tilmicosin against undifferentiated bovine respiratory disease in feedlot cattle. Veterinary Therapeutics. 6:180-196.
Snowder, G.D., LD. Van Vleck, L.V. Cundiff, and G.L. Bennett. 2006. Bovine respiratory disease in feedlot cattle: Environmental, genetic, and environmental factors. Journal of Animal Science. 84:1999-2008.
Wildman, B.K., T. Perrett, S.M. Abutarbush, P.T. Guichon, T.J. Pittman, C.W. Booker, O.C. Schunicht, R.K. Fenton, and G.K. Jim. 2008. A comparison of two vaccination programs in feedlot calves at ultra-high risk of developing undifferentiated fever/bovine respiratory disease. Canadian Veterinary Journal. 49:463-472.
Prevention and Treatment for Bovine Respiratory Disease in High Risk, Newly Received Stocker Calves
Bovine Respiratory Disease (BRD) is one of the leading causes of morbidity and mortality in stocker and feedlot operations. Cattle in these operations are highly susceptible to contracting the disease and are classified as high or low risk based on a number of factors; “commingling with other animals, transportation stress, immune status, nutritional condition, environment conditions, and the skill level of management to diagnose cattle displaying symptoms of BRD” (Richeson, 2008). Cattle entering stocker and/or feedlot operations are normally classified as high risk if originating from livestock auctions for reasons including “unknown origin, commingling with numerous other animals, and being recently weaned from small cow-calf operations that seldom use vaccination or other BRD prevention strategies” (Richeson, 2009). Because the number of cattle classified as high risk is relatively high in the stocker and feedlot industry, it is important to find the most effective methods of prevention and treatment for BRD. Although there have been many research trials conducted showing the impact of BRD on cattle, this focus of this paper will be on the methods of prevention and treatment for BRD including 14-day delayed modified live virus vaccination and the efficacy of treatment with different medications.
BRD does have a major impact on health, efficiency, and performance of stocker and feeder calves. According to research from Snowder et al. (2006), BRD has a large impact on both stocker and feeder calves, with 13% and 17%, respectively, of calves being affected by the disease. Snowder’s research shows results of an average economic loss of $15.57 per sick animal. This figure only includes treatment costs and losses from decreased average daily gain (ADG). Similar research conducted by Brooks et al. (2009) shows that BRD has a major effect of costs associated with production. Cattle in this research trial had a decreased ADG of two and a half pounds per day, increased treatment costs of thirty-five dollars per head, and decreased net returns of one hundred fourteen dollars per head, compared to cattle not affected by BRD. These figures show a decrease in economic gains and performance of cattle diagnosed with BRD.
Stress levels at time of initial vaccination can influence the efficacy of modified live virus (MLV) vaccines and health and performance of newly received stocker calves. Richeson et al. (2008) conducted research to evaluate the health, performance, and serum infectious bovine rhinotracheitis (IBR) titers in newly received calves. In this research, stocker calves were tested in two treatments; on arrival vaccination with a MLV vaccine (AMLV) or 14-day delayed MLV vaccination (DMLV). The cattle on the delayed treatment performed better than AMLV cattle with increased body weight (BW) on days fourteen and forty-two (212.7 vs. 208.6kg, p=0.007; 228.1 vs. 224.4kg, p=0.07 (approaching significance), respectively) and greater ADG in periods day-0 thru day-14 and day-0 thru day-42 (1.16 vs. 0.88kg/day, p=0.007; 0.75 vs. 0.65kg/day, p=0.05, respectively). Measurements for effect of vaccination timing on morbidity, mortality, and treatment cost suggest no advantage between the two treatments (AMLV vs. DMLV). Factors involved in these measurements include rectal temperature on day-0 (39.6 vs. 39.6°C, p=0.83), initial BRD treatment (71.5 vs. 63.5%, p=0.12), retreat BRD treatment (25.1 vs. 30.8%, p=0.17), days to first treatment (7.2 vs. 7.7, p=0.72), death loss (2.3 vs. 0.8%, p<0.16), and BRD treatment cost (9.00 vs. $8.75, p=0.76). Morbidity rates were high for both treatments in the trial and did not differ (71.5 vs. 63.5%, p=0.12). Ninety three percent of the BRD cases occurred during the first fourteen days of the trial, suggesting there is no advantage to AMLV treatment to reduce morbidity rates.
Seroconversion rates for IBR titers were measured in the study from Richeson et al. (2008). These measurements show substantially greater amounts of IBR antibodies in the blood system of the calves in the DMLV treatment on day-28 and day-42 after initial vaccination as well as at the end of the trial (p=0.03, p=0.01, p=0.01, respectively). These data suggest an increased vaccine efficacy, likely due to lower stress levels at time of initial vaccination. Later research from Richeson et al. (2009) shows different results. Initially greater (p<0.01) titer levels were present in calves with on-arrival vaccination, but total white blood cell counts were greater for the delayed treatment group. Collectively, the data from these studies suggest an economic advantage to delaying initial MLV vaccination until fourteen days after receiving to improve body weight, average daily gain, and vaccine efficacy.
Research conducted by Wildman et al. (2008) has shown that the type of vaccination given to cattle has an impact on response and number of cases for BRD. In this study, cattle were given MLV vaccines with one or two types of bovine viral diarrhea (BVD) virus. The vaccine type had an effect on the treatment for BRD (p<0.001), mortality rate (p=0.002), and ADG (p=0.008). The rate of BRD cases correlated with the number of yield grade three carcasses, suggesting an economic loss for cattle affected by BRD through the entire cycle, from weaning to harvest. This study enforced the findings of Richeson et al. (2008, 2009) that there is an economic advantage to a well-managed vaccination program as a means of prevention of BRD.
There are several products on the market for treatment of BRD including tilmicosin phosphate (Micotil, Elanco Animal Health), tulathromycin (Draxxin, Pfizer Animal Health), florfenicol (Nuflor, Schering-Plough Animal Health), and enroflaxacin (Baytril, Bayer Animal Health). Use of these medications is for treatment in cases of BRD sickness and mass treatment in high risk newly received calves. Gaylean et al. (1995) conducted a study on the use of tilmicosin phosphate as an arrival medication for mass treatment. Three trials were included in this study to test the effectiveness of tilmicosin phosphate. Trial one involved calves given Micotil on-arrival as a mass treatment and calves were fed a receiving supplement for the duration of the study. Weight gains were greater (p<0.10) for calves receiving on-arrival mass medication than control calves during the first half of the trial but did not differ (p=0.17) over the 28-day period. Dry matter intake (p<0.22) and feed to gain ratio (p<0.81) did not differ between treatments. 46.4% of the control calves were treated for BRD, but none of the mass treatment calves was treated for BRD. The second trial involved mass treatment calves grazing winter wheat pasture. BW and ADG did not differ (p<0.51, p=0.06) between treatments. There was fewer (12.1%) mass control calves treated for BRD than control calves (32.8%). Trial three in this study included three treatments: control, mass treatment with Micotil, and treatment with Micotil when body temperature was greater than 39.7°C (104°F). Calves in this trial were fed a 65% concentrate diet. Calves in this trial receiving Micotil, both mass treatment and treatment by temperature, gained more than control calves (p<0.01). Dry matter intake and feed to gain ratio were lower for calves in the medicated groups than control (p<0.09, p<0.03). No differences were shown between medicated groups. This study has shown that Micotil is highly effective as a mass treatment to increase gains and dry matter intakes. Treated calves had a lower rate of treatment for BRD symptoms. The third trial in this study showed that treatment with Micotil based on body temperature was as effective as mass treatment and reduced the number of calves treated; lowering arrival medication costs.
Studies have been conducted to evaluate the effectiveness of Draxxin. Nutsch et al. (2005), Skogerboe et al. (2005), and Rooney et al. (2005) have all shown that Draxxin is more effective as a treatment than Nuflor or Micotil. Nutsch’s and Skogerboe’s studies resulted in greater weight and performance, and lower retreatment and chronic rates in treatments using Draxxin over Nuflor or Micotil. Rooney’s study showed that when used as a mass treatment, Draxxin decreases morbidity rates and performance of cattle. Collectively these studies show the advantage of Draxxin over other drugs for the treatment and prevention of BRD in newly received stocker calves.
BRD is a major factor in the performance of newly received beef calves in the stocker industry with 13% and 17% of stocker and feeder calves being affected (Snowder, 2006). Cattle affected by BRD often have lower performance with decreased body weights, average daily gains, feed to gain ratios, and dry matter intakes. Morbidity and mortality rates increase cost of gain and decrease net returns for producers by up to $114 per head (Brooks, 2009), making it important to find the most effective means of treatment and prevention for BRD. Richeson et al. (2008, 2009) and Wildman et al. (2008) have shown that delaying treatment with MLV vaccinations by 14 days will increase performance and gains of cattle, increase days to first treatment, as well as decrease morbidity, mortality, and chronic rates and treatment costs in stocker cattle. Vaccine efficacy and calves’ immune response to MLV vaccines is greater when MLV treatment is delayed by 14 days. Several studies have shown that mass medication by Micotil or Draxxin are effective as a means of mass treatment to prevent BRD and reduce the number of retreats and chronics in stocker calves Richeson, 2008; Nutsch 2005).
In conclusion, every situation is different depending on environment and diseases present in the animal herd, so treatment efficacy may differ between operations. Research has shown that delaying MLV vaccination treatment by 14-days combined with mass treatment or treatment by temperature with tilmicosin phosphate or tulathromycin will increase performance and returns in newly received stocker calves at high risk for bovine respiratory disease. With this information, producers will be able to make more informed decisions when creating vaccination and treatment protocols.
Literature Cited
Brooks, K., K.C. Raper, C.E. Ward, B.P. Holland, and C. Krehbiel. 2009. Economic effects of bovine respiratory disease on feedlot cattle during backgrounding and finishing phases. Southern Agricultural Economics Association Annual Meeting.
Galyean, M.L., S.A. Gunter, and K.J. Malcolm-Callis. 1995. Effects of arrival medication with tilmicosin phosphate on health and performance of newly received beef cattle. Journal of Animal Science. 73:1219-1226.
Nutsch, R.G., T.L. Skogerboe, K.A. Rooney, D.J. Weigel, K. Gajewski, and K.F. Lechtenberg. January 2005. Comparative efficacy of tulathromycin, tilmicosin, and florfenicol in the treatment of bovine respiratory disease in stocker cattle. Veterinary Therapeutics. 6:167-179.
Richeson, J.T., E.B. Kegley, M.S. Gadberry, P.A. Beck, J.G. Powell, and C.A. Jones. July 2009. Effects of on-arrival versus delayed clostridial or modified live respiratory vaccinations on health, performance, bovine viral diarrhea virus type I titers, and stress and immune measures of newly received beef calves. Journal of Animal Science. 87:2409-2418.
Richeson, J.T., P.A. Beck, M.S. Gadberry, S.A. Gunter, T.W. Hess, D.S. Hubbell, III, and C. Jones. 2008. Effects of on-arrival versus delayed modified live virus vaccination on health, performance, and serum infectious bovine rhinotracheitis titers of newly received beef calves. Journal of Animal Science. 86:999-1005.
Rooney, K.A., R.G. Nutsch, T.L. Skogerboe, D.J. Weigel, K. Gajewski, and W.R. Kilgore. January 2005. Efficacy of tulathromycin compared with tilmicosin and florfenicol for the control of repiratory disease in cattle at high risk of developing bovine respiratory disease. Veterinary Therapeutics. 6:154-166.
Skogerboe, T.L., K.A. Rooney, R.G. Nutsch, D.J. Weigel, K. Gajewski, and W.R. Kilgore. January 2005. Comparative efficacy of tulathromycin versus florfenicol and tilmicosin against undifferentiated bovine respiratory disease in feedlot cattle. Veterinary Therapeutics. 6:180-196.
Snowder, G.D., LD. Van Vleck, L.V. Cundiff, and G.L. Bennett. 2006. Bovine respiratory disease in feedlot cattle: Environmental, genetic, and environmental factors. Journal of Animal Science. 84:1999-2008.
Wildman, B.K., T. Perrett, S.M. Abutarbush, P.T. Guichon, T.J. Pittman, C.W. Booker, O.C. Schunicht, R.K. Fenton, and G.K. Jim. 2008. A comparison of two vaccination programs in feedlot calves at ultra-high risk of developing undifferentiated fever/bovine respiratory disease. Canadian Veterinary Journal. 49:463-472.
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