The response to artificial infection with Haemonchus contortus and growth performance of sheep and goat progeny of selected parents in a central performance test

TitleThe response to artificial infection with Haemonchus contortus and growth performance of sheep and goat progeny of selected parents in a central performance test
Publication TypeJournal Article
Year of Publication2016
AuthorsTsukahara, Y, Gipson, TA, Hart, SP, Dawson, LJ, Wang, Z, Puchala, R, Sahlu, T, Goetsch, AL
JournalJournal of Animal Science
Volume94
IssueE-Supplement 5
Start Page817
AbstractFifteen Katahdin (KS-A; 4.0 mo old, 38 kg), 5 Katahdin (KS-B; 3.0 mo, 20 kg), 16 Dorper (DS; 3.4 mo, 25 kg), and 17 St. Croix sheep (CS; 4.2 mo, 18 kg) and 20 Kiko (KG; 3.9 mo, 19 kg), 16 Boer (BG; 4.4 mo, 16 kg), and 18 Spanish goat (SG; 4.3 mo, 18 kg) males from 5 commercial farms in KS, MO, and AR and Langston University (LU) were used to investigate growth performance and response to artificial infection with Haemonchus contortus in year 3 of a central test at LU. Animals tested were progeny of dams (based on on-farm data) and sires classified as Resistant and Moderate in year 2. The test entailed an adjustment period of 2 wk followed by 8 wk of data collection. Animal groups were housed separately in adjacent pens with automated feeders allowing free-choice access to a 15% CP diet. During adaptation, anthelmintic treatment resulted in low fecal egg count (FEC; <600 eggs/g), after which 10,000 larvae were administered orally. Packed cell volume (PCV) was measured weekly and FEC was determined 5 times in wk 5-9. The cubic clustering criterion of SAS® categorized resistance classes. The GLM procedure included animal group and resistance classification, initial BW, PCV, and FEC were covariates, and the logarithmic transformation ln(x+100) was used for mean FEC. Animal group affected (P<0.01) ADG (308, 264, 321, 254, 139, 243, and 147 g; SEM=14.6), DMI (2.34, 1.65, 1.65, 1.32, 0.79, 1.28, and 0.94 kg/d; SEM=0.069), and PCV (25.4, 24.3, 28.6, 29.3, 25.8, 22.9, and 25.7% for KS-A, KS-B, DS, CS, KG, BG, and SG, respectively; SEM = 0.65). The resistant males had highest (P=0.04) ADG (256, 237, and 225 g for Resistant, Moderate, and Susceptible, respectively; SEM=8.8). There was an animal group×resistance classification interaction (P=0.04) on FEC (270, 2,346, and 4,633 with KS-A, 1,088, 5,272, and 8,263 with KS-B, 442, 1,140, and 2,370 with DS, 209, 870, and 2,368 with CS, 248, 994, and 2,431 with KG, 1,182, 2,164, and 4,523 with BG, and 215, 1,203, and 3,132 eggs/g (untransformed) with SG for Resistant, Moderate, and Susceptible classes, respectively; SEM=295.0). The correlation coefficient between sire and progeny FEC was 0.27 (P=0.004) and that of PCV was 0.44 (P<0.001). In conclusion, selection for resistance did not adversely affect performance of males, and there were moderate relationships between indices of parasite infection of sires and progeny.