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The Center held its third Sheep and Goat Field Day on September 30 and October 1, 2005. On the afternoon of September 30, Center staff hosted an informal tour of the facilities followed by a dinner. Presentations by sheep and goat researchers and technology transfer specialists were made during the morning of October 1. The afternoon program featured more hands-on workshops. Center field days are not possible without support from the local community. Therefore, we want to thank the following for their support of the 3rd Sheep and Goat Field Day: Booneville Industrial Development Corporation, Booneville Development Corporation/Chamber of Commerce, Coffman Foods, Arkansas Meat Goat Association, Booneville’s CV’s Grocery and the South Logan County Fair board. Special thanks to Dr. Joan Burke for organizing the field day.
Presentations from the field day are available on the internet at ------. If you do not have internet access and would like a copy of these presentations, please contact the Center. The following are my notes of items that I thought are of interest from these presentations.
Presentations: Novel approaches to GI parasite control by Drs. Burke (ARS, Booneville AR) and Miller (Louisiana State University)
An examination of the life cycle of H. contortus indicates that only a small percentage of the parasites in a pasture ecosystem reside in the animal at any one time. Therefore, when farmers treat animals they are only affecting a small percentage of the parasites in the environment. So animals are going to be re-infected and there is an increased likelihood that resistance to chemical dewormers will occur. H. contortus tends to persist in pastures. The life cycle of H. contortus is relatively short (3 weeks), the transmission season in the SE United States is long and the ability of the parasite to survive in the soil during the winter is high. These characteristics of H. contortus life cycle also may indicate that rotational grazing may have only minimal effects on the parasite. Rotational grazing schemes that maintain at least 2 to 3 inches of forage, however, should reduce the effects of the parasite by decreasing the ingestation of the larva by sheep and goats.
Spanish goats appear to have a greater resistance to H. contortus than Boer goats.
A 5 g dose of oxidized copper wire particle bolus or a trace element bolus (3.7 g copper) is adequate for goats but may be too high of a dose for sheep. The copper wire particle bolus appears to be effective means of treating H. contortus in kids and lambs but not mature sheep. The interest in tanning rich forages as a means of controlling H. contortus appears to be related to the ability of tannins to disrupt egg production and/or female maturation of the parasite.
FAMACHA (eye score for anemia) is a tool to determine which animals to treat with chemical dewormers. FAMACHA can also be used to identify animals that are most susceptible to parasites. Thus, farmers hopefully can decrease the effects of internal parasites by genetic improvement by culling most susceptible animals.
Liver flukes are an infrequent problem in sheep and goats. Problems with liver flukes tend to be limited to very wet areas. The parasite affects several species including sheep, goats, humans and horses. The vaccines for liver flukes works well in sheep and is currently being tested for goats.
Presentation: Reproduction Management by Dr. Stephan Wildeus (Virginia State University)
Dr. Wildeus presented a fact filled seminar regarding sheep and goat reproduction. Dr. Wildeus indicated that estrus synchronization and thus artificial insemination systems for sheep and goats are not well developed. This has been an area of a collaborative study between Dr. Looper (ARS, Booneville AR) and scientists at Langston University in Oklahoma. A summary of that research to date is below.
Presentation: Langston Nutrition Calculator by Dr. Steve Hart (Langston University)
Dr. Hart presented information about an internet based tool that producers can used to create rations for sheep and goats and determine if supplements need to be added to the diet of grazing animals. This tool can be found at www.luresext.edu/goats/research/nutreqgoats.html.
Presentation: Organic Livestock Production by Ms. Linda Coffey (National Center for Appropriate Technology, NCAT)
The term organic production can mean different things when producing livestock. Livestock can be raised on organic grown pastures. Such a designation does not imply that the animal husbandry methods are organic. For livestock to be designated organically grown, the production methods must adhere to the organic standards from two-thirds of the way through gestation to slaughter. Ms. Coffey indicated that NCAT has many publications related to organic farming and sustainable livestock production. These publications can be accessed via the internet at www.ncat.org.
Research Update: Use of an intravaginal progesterone insert (CIDR) to enhance reproduction in Alpine does. Dr. Mike Looper
An increase in the popularity of goat production within the last decade for meat and milk products has generated increased interest in reliable methods to synchronize estrus in goats. In collaboration with Langston University in Oklahoma, Dr. Mike Looper recently completed an experiment investigating the use of two hormones, progesterone, via a CIDR, and prostaglandin F2α (PGF2α), on synchronization and pregnancy rates of non-lactating Alpine does. Approximately one-half of the does received a CIDR for 12 d while the other one-half did not receive CIDRs. Does with a CIDR were administered PGF2α 15 hours prior to CIDR removal. A second goal of this experiment was to compare visual estrous detection with a novel radiotelemetry system. This system monitors estrous activity 24 hours/day with a pressure sensor and battery-operated radio transmitter attached to the rump of the doe. All does were fitted with a transmitter and visually observed twice daily (7 a.m. and 5 p.m.; 20 minutes at each observation) to confirm behavioral estrus. Does were exposed to bucks (1 buck/5 does) with marking harnesses, and ultrasound of the reproductive tract was performed to determine pregnancy of does at approximately 57 days after breeding. Visual observation verified that 50% of does exhibited behavioral estrus within 24 hours after CIDR removal, and 93% of does within 48 hours after CIDR removal suggesting these two hormones can efficiently synchronize estrus in does. Pregnancy rate was not affected by treatment of does with a CIDR and PGF2α. Interestingly, visual observation was more accurate at detecting does in estrus than the radiotelemetry system. The radiotelemetry system detected only 50% of does identified by visual observation as exhibiting estrus. The failure of the radiotelemetry system to accurately detect estrus in goats may be due to the sloping rump of most goats. The use of hormones to synchronize estrus will allow does to produce offspring during a more concise period of time resulting in less labor inputs and a more uniform group of kids.
Recent scientific articles from the Center regarding goat and sheep production
Burke, J.M., Miller, J.E. Brauer, D.K. 2005. The effectiveness of copper oxide wire particles as an anthelmintic in pregnant ewes and safety to offspring. Veterinary Parasitology 131:291-297.
Widespread resistance of gastrointestinal worms to chemical dewormers has led to the need for alternative parasite control, especially around the time of lambing. Copper oxide wire particles (COWP), used as an alternative control for gastrointestinal parasites in sheep, has not been examined during late pregnancy. COWP decreased parasite infection in pregnant Katahdin ewes, but newborn lambs from ewes receiving the highest does of COWP may have been more susceptible to copper toxicity. These results indicate that low level of COWP may be suitable for parasite control.
Kaplan, R.M, Burke, J.M., Terrill, T.H., Miller, J.E., Getz, W.R., Mobini, S., Valencia, E., Williams, M.J., Williamson, L.H., Larsen, M., Vatta, A.F. 2004. Validation of the famacha eye color chart for detecting clinical anemia in sheep and goats on farm in the southern United States. Veterinary Parasitology 123:105-120.
Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. The objective was to validate a system of identifying animals for treatment of H. contortus infection using eye color scores. Results indicate that the FAMACHA© method is an extremely useful tool for identifying anemic sheep and goats in the southern U.S. and U.S. Virgin Islands. This information is important to small ruminant producers throughout the U.S. and Virgin Islands to manage internal parasites.
Looper, M.L., Edrington, T.S., Rosenkrans, Jr., C.F., Burke, J.M., Flores, R., Callaway, T.R., Aiken, G.E. 2005. Effects of feeding endophyte-infected tall fescue seed to sheep experimentally infected with Escherichia coli O157:H7. Western Section of Animal Science Proceedings. 56:213-216.
Escherichia coli O157:H7 causes foodborne illness in humans. Data investigating the effects of endophyte-infected tall fescue on E. coli O157:H7 were fed diets containing endophyte-infected (E+) or endophyte-free (E-) tall fescue seed for 7 d. Fecal shedding of E. coli O157:H7 was decreased in E- ewes compared with E+ ewes. This information is of interest to livestock producers, extension personnel, and agricultural professionals who advise producers on livestock and food safety management practices.
Burke, Joan M., Parker C.F. Effect of breed on response to foot rot treatment in sheep. Submitted to Small Ruminant Research.
Virulent foot rot is a contagious disease of small ruminants resulting in reduced weight gains, wool production, and increased culling rate. Response to eradication treatment, which will decrease culling rate, has not been examined in hair breeds of sheep. Treatment included hoof paring, foot bathing with 10% zinc sulfate with surfactant, allowing the zinc sulfate to dry on the foot and moving to a small paddock that had not been exposed to small ruminants for more than 14 d. Foot bathing was repeated every 7 d for a maximum of five treatments. In this study, there may have been more initial signs of foot rot in the Dorper sheep, but response to treatment was similar among wool breeds (Dorset and Gulf Coast Native) and hair breeds (Dorper, Katahdin, and St. Croix); growing lambs responded better than mature sheep. These results indicate all breeds examined were susceptible to foot rot and responded well to an eradication program.
Burke, J.M., Bishop, Cecily, Stormshak, Fredrick, Thatcher, William W., Smith, Michael F. Ovarian characteristics of endophyte-infected tall fescue fed ewes. Submitted to Biology of Reproduction.
Pregnancy rates are often reduced in female ruminants grazing endophyte-infected tall fescue and costs the beef industry millions of dollars annually. Changes in reproductive function that lead to decreased pregnancy rate are unclear and cost-effective supplements to increase pregnancy rates have not been found. The current study determined that there was a decrease in oxytocin-induced prostaglandin F2alpha, which indicates a change in uterine function, and asynchrony in reproductive tissue function, but supplementary fish meal did not alleviate these problems. These results provide an insight into mechanisms for reproductive failure in females grazing endophyte-infected tall fescue, information that is important to producers, extension agents, and scientists.
Burke, Joan M. Lamb production of Dorper, Katahdin, and St. Croix bred in summer, winter, or spring in the southeastern U.S. Submitted to Sheep and Goat Research Journal.
The use of hair breeds for lamb production has increased significantly over the past few years because of ease of management. Little has been reported about out-of-season breeding and ewe lamb performance in the U.S. Data presented in this publication indicates Dorper, Katahdin, and St. Croix ewes were all capable of breeding out-of-season; however summer heat stress increased pregnancy and lamb losses in Dorper ewes. These results indicate which breeds are suitable for seasonal breeding schemes in the southeastern U.S.
Burke, J.M., Miller, J.E., Larsen, M., Terrill, T.H. Interaction between copper oxide wire particles and Duddingtonia flagrans in lambs. Veterinary Parasitology 134:141-146.
Widespread resistance of gastrointestinal worms to chemical dewormers has led to the need for alternative parasite control. Copper oxide wire particles (COW)) and the nematode-trapping fungus Duddingtonia flagrans have been used as alternative controls for gastrointestinal parasites in sheep, but not concurrently. There was no adverse effect of COWP on the ability of the fungus to trap residual larvae after COWP treatment and a beneficial effect to lambs receiving both treatments. These results indicate that COWP and D. flagrans are a sustainable means of controlling parasites on pasture.
  
  
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