Growth performance and resistance to internal parasitism of small ruminant males from the south-central US in a centralized test

TitleGrowth performance and resistance to internal parasitism of small ruminant males from the south-central US in a centralized test
Publication TypeWeb Article
Year of Publication2015
AuthorsTsukahara, Y, Gipson, TA, Hart, SP, Dawson, LJ, Wang, Z, Puchala, R, Sahlu, T, Goetsch, AL
Series TitleJournal of Animal Science
Edition93
Type of Medium(Supplement s3)
Abstract

Performance of young male sheep and goats from different farms and of various breeds was determined in a centralized test at Langston University (LU), which included artificial infection with Haemonchus contortus. Year 1 included 2 Katahdin flocks (KS-A, n = 17, 3.5 mo of age, 35 kg; KS-B, 18, 4.0 mo, 19 kg), 20 Dorper (DS; 8.2 mo, 45 kg), 13 St. Croix (CS; 4.4 mo, 21 kg), 2 Boer herds (BG-A; 16, 3.8 mo, 21 kg; BG-B, 17, 19 kg) 16 Kiko (KG; 3.1 mo, 20 kg), and 14 Spanish (SG; 4.4 mo, 19 kg). In year 2, animals were progeny from breeding groups classified in year 1 as of high and moderate resistance, with 15 DS (3.8 mo, 29 kg), 14 CS (3.9 mo, 18 kg), 14 KG (4.0 mo, 19 kg), 13 BG-A (3.2 mo, 22 kg), and 17 SG (3.1 mo, 18 kg). Thus, the test included males from 8 flocks/herds, 6 commercial farms in AR, KS, MO, and OK and 2 herds of LU (i.e., B-A and S). There was 2 wk for adaptation and an 8-wk test period, with automated feeders allowing free-choice access to a 50% concentrate pelletized diet. During adaptation, anthelmintic treatment resulted in low fecal egg count (FEC; 0.05) for ADG and ADG:DMI in both years. In conclusion, based on FEC after an artificial challenge with H. contortus larvae in a standardized environment, there was considerable variability among flocks/herds of small ruminants in resistance to internal parasitism due to multiple factors such as species, breed, and genetic differences within breed.