Recap of the 2016 Buck Test
2016 was the 11th year of the Western Maryland Pasture-Based Meat Goat Performance Test, which is conducted at the University of Maryland's Western Maryland Research & Education Center in Keedysville. The purpose of the test is to evaluate the post-weaning performance of meat goat bucklings consuming a pasture-based diet, with natural exposure to gastro-intestinal parasites, primarily the barber pole worm (Haemonchus contortus).
2016 was the biggest year ever, as 142 bucks were consigned to the test. The mostly Kiko bucks were consigned by 38 breeders from 17 states (Alabama, Delaware, Georgia, Illinois, Indiana, Kansas, Kentucky, Maryland, North Carolina, Oklahoma Pennsylvania, South Carolina, Tennessee, Vermont, Virginia, and West Virginia). Fourteen were first-time consignors. Twenty-four had consigned to one or more prior tests. Consignments were reduced to 100 goats. Ninety-seven bucks were delivered to the test site on June 23-24. Ninety-six (96) started the test on July 7-8. Eighty-three (83) finished the test on September 15. Four died and nine were removed from the test, due to their inability to adapt to test conditions.
Upon arrival, the bucks were sequentially dosed with anthelmintics from all three anthelmintic classes: albendazole (Valbazen® @ 2 ml/11 lbs), moxidectin (Cydectin® @ 2 ml/11 lbs.) and levamisole (Prohibit® @ 3 ml/50 lbs.). The reason for the sequential deworming was to make sure all the bucks started the test equally and "free" from worms. Fecal egg counts from June 23-24 and July 8 were compared to determine the efficacy of the sequential dosing. For the fifteen goats that had fecal egg counts >1000 epg, the sequential dosing reduced egg counts by an average of 84 percent. If the odd data point is eliminated (one goat had only a 1% reduction in FEC), the average fecal egg count reduction in these goats was 90%. Several goats with low initial fecal egg counts experienced substantial increases in fecal egg counts after the sequential dosing, indicating a resistant population of immature worms upon arrival.
While on test, the bucks were evaluated for growth performance (ADG), parasite resistance (FECs), and parasite resilience. They were handled every two weeks to determine body weights, FAMACHA©, body condition, coat condition, dag, and fecal consistency scores. FAMACHA© scores and the Five Point Check© were used to make deworming decisions. Weight gain and fecal egg counts were also factored into deworming decisions for goats with FAMACHA© scores of 3. It was often necessary to administer at least two dewormers to alleviate the symptoms of clinically-parasitized goats. Fecal samples were collected from each buck every two weeks to determine individual fecal egg counts. Pooled samples were collected twice for larvae ID and the DrenchRite® test.
While on test, the bucks were managed as a single group on pasture. They were rotationally grazed among six paddocks, with continous access to a central laneway, containing port-a-hut shelters, mineral feeders, water troughs, environmental enrichment, and a handling system. The pasture system consists of five, 2-acre paddocks, along with a 2.5 acre silvopasture (walnut and mixed hardwood trees). Half of the pasture is planted in perennial cool season grasses: MaxQ™ tall fescue and orchardgrass. Half of the pasture is planted in warm season annual grasses and legumes. This year's annual plantings included dwarf pearl millet and Sunn Hemp.
There was a 13-day adjustment period, followed by an 70-day test period. The test was stopped at 70 days, due to an outbreak of respiratory disease. The first 42 days of the test served as a "growth challenge." The bucks grazed "clean" warm season forages. The second half of the test served as a "parasite challenge." The bucks grazed cool season grass paddocks that had been previously infected with worm larvae by grazing sheep.
During the test period, the goats were supplemented daily with whole barley. Previous data had shown the test goats' pasture-only diet to be deficient in energy. Barley was introduced to the diet slowly and gradually increased according to appetite. The maximum consumpion of barley was approximately 1 lb. per head per day. Depending upon the weight of the goats, this ranged from 1.25 to 2.5 percent of body weight.
Delivery weights ranged from from 32.4 to 79.2 lbs, and averaged 47.6 ± 9.2 lbs. The median delivery weight was 45.6 lbs. Nineteen bucks failed to meet the minimum weight requirement of 40 lbs. Four bucks exceeded the maximum weight requirement of 70 lbs. Starting (on-test) weights were determined by weighing the goats on consecutive days (July 7-8) and averaging the two weights. Starting weights ranged from 32.4 to 78.8 lbs. and averaged 50.1 ± 8.9 lbs. The median starting weight was 49.6 lbs. During the 13-day adjustment period, the goats gained an average of 2.1 ± 3.4 lbs. The median gain was 2.5 lbs. ADG during the adjustment period ranged from -0.592 to 0.693 lbs. per day and averaged 0.149 ± 0.245 lbs. per day. The median ADG was 0.179 lbs. per day.
For the first 42 days, ADG ranged from -0.150 to 0.317 lbs. per day and averaged 0.116 ± 0.097 lbs. per day. The median ADG was 0.118 lbs. per day. The top-gaining goat was a buck consigned by P.J. Murphy (New Jersey). Ending weights were determined on September 15. Ending (off-test) weights ranged from 40.4 to 84.0 lbs. and averaged 57.0 ± 10.1 lbs. The median ending weight was 55.4 lbs. For the 70 day duration of the test (and for the 84 goats that finished the test), ADG ranged from -0.093 to 0.294 lbs. per day and averaged 0.108 ± 0.084 lbs. per day. The median ADG was 0.108 lbs. per day. The top-gainer was a buck consigned by Jarred Dennison. Two other bucks gained more than 0.25 lbs. per day: Loos (Illinois) and Gamby (Ohio). Thirteen bucks gained 0.20 lbs. per day or more. Angie Loos had two goats ranked in the top 10 for gain. Twelve goats lost weight during the test period.
Upon arrival, fecal egg counts ranged from 0 to 21550 epg and averaged 1070 ± 3024 epg. The standard deviation was nearly three times the mean indicating a wide variation in initial fecal egg counts. The median was 125 epg, indicating that most goats started the test with a very low level of parasite infection. Four weeks after the initial dewormings, fecal egg counts began to increase. They continued to increase (substantially) as the test progressed. The number of goats that required deworming also increased as the test progressed. Each goat was dewormed an average of 0.8 times. Forty-three (44%) goats did not require deworming during the test. On September 15 (due to high and rising egg counts), all of the bucks were given a 1 g dose of copper oxide wire particles (COWPs).
Pooled fecal samples were collected twice for larvae ID and a DrenchRite® test. The initial worm load carried by the goats was 70 percent Haemonchus contortus (barber pole worm). On August 3, the proportion of Haemonchus had increased to 90 percent. The DrenchRite® test showed that the worm population was resistant to all four dewormer groups: benzimidazoles (SafeGuard® and Valbazen®), avermectins (Ivomec®, Dectomax®, and Eprinex®), moxidectin (Cydectin®), and levamisole (Prohibit® and LevaMed®).
On the last day of the test, the bucks were evaluated for reproductive soundness and structural correctness. Scrotal circumference was measured. Measurements ranged from 17.5 to 27.0 cm and averaged 22.6± 2.1 cm. Teats were counted and characterized. Only two bucks had supernumerary teats or teat defects. The bite of each buck was checked. No buck displayed a significant over- or underbite. The bucks were evaluated for structure and movement. No abnormalities were noted. Hooves were examined for growth and abnormalities. Only one buck had abnormal hoof growth (abnormal heel growth).
John Weber from Illinois had the top-performing buck in this year’s test. His buck excelled in all performance categories. Other top-5 performing bucks were consigned by Steven Yutzy (Ohio), P.J. Murphy (New Jersey), David Peters (North Carolina), and Thomas Davis (Missouri). Davis and Yutzy were first-time consigners to the test. Murphy, Peters, and Weber have consigned to the test for 5, 4, and 3 years, respectively. Weber was the top-consigner (tied) in 2013 and has had top-performing bucks in other tests.
The second five in the top-10 included bucks consigned by P.J. Murphy, Jarred Dennson (Kentucky), Patricia Larr (Indiana), Richard Gamby (Ohio), and Angie Loos (Illinois). Richard Gamby was a first time consigner. All other consigners had previously consigned bucks to the Maryland test. The top consigner award went to the consigner with the three best bucks. This year’s top consigner was Jarred Dennison from Kentucky. Dennison had two bucks in the top-10. He also had the top-gaining buck. It was the 7th year Dennison consigned bucks to the test. He has had top-performing bucks in the prior tests.
Only five bucks met the traditional Gold, Silver, and Bronze standards of performance for parasite resistance (Avg. FEC<1000 EPG and High FEC<2000 EPG). Only one buck met the Gold standard (Avg. FEC<500 EPG and High FEC<1000 EPG).
The most resistant buck in this year's test was a buck consigned by David Peters from North Carolina. Its average fecal egg count was 364 epg. It's highest egg count (September 15) was 920 epg. Peters also had the most resistant buck in 2015. In September, this buck brought $4000 at the Bluegrass Performance Invitational Sale in Frankfort, Kentucky. Some of this year's top-performing bucks may be sold at next year's BPI sale in Kentucky.
The progress reports and summary reports from the 2016 year's test can be downloaded from the blog or http://www.sheepandgoat.com/goattest. Reports from previous tests are available at the same web site.
No Test in 2017
The Western Maryland Pasture-Based Meat Goat Performance Test will not be held in 2017. After 11 years of the test and 13 years of small ruminant grazing, the test site will be rested. All of the vegetation has been killed, and the site will be planted in row crops in 2017. It will be replanted in forages next fall.
The present test has run its course. High levels of parasite infection, coupled with lack of efficacy of the anthelmintics (dewormers) has resulted in too many goats being unable to adapt to test conditions. A new test will be considered for 2018. Many changes would be necessary, including 1) lower stocking rates (fewer goats); 2) selection of out-of-state goats based on a lottery system; 3) strict enforcement of minimum weight requirement (40 lbs); 4) grass-free laneway; 5) different supplementation strategy; and 6) removal of sheep from the grazing system.
Dealing with the high level of anthelmintic resistance is a more difficult challenge to overcome. Requiring a fecal egg count reduction of 95% or more after the sequential deworming (the research standard) would result in few goats remaining in the test. Goats with zero or low egg counts would also have to be eliminated if their egg counts went up significantly after the sequential deworming, as this is indicative of resistant immature warms.
The dewormer resistance doesn't mean a goat can't be effectively treated, as combination treatments usually alleviate clinical symptoms (anemia and bottle jaw), but resistance makes it difficult to get valid fecal egg count (resistance) data.
Parasite resistance has always been the trademark of the Maryland test.
Comments and suggestions pertaining to the test are always welcome. Send to firstname.lastname@example.org.