Thorne Jacob W, Bowdridge Scott A, Murdoch Brenda M, Redden R Reid
Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, ID 83844, USA.
Texas A&M AgriLife Research and Extension, San Angelo, TX 76903, USA.
Animals (Basel). 2022 May 6;12(9):1199. doi: 10.3390/ani12091199.
Gastrointestinal nematodes (GIN) threaten the productivity and health of sheep worldwide, prompting the need for genetic selection to reduce GIN susceptibility. Fecal egg count (FEC), packed-cell volume (PCV), and various production traits were examined in parasitized Rambouillet sheep and compared to sire FEC estimated breeding value (EBV). Rambouillet lambs (n = 77) were inoculated with 10,000 H. contortus L3 larvae. Subsequently, FEC, PCV, and body weight (BW) were captured at seven-day intervals for six weeks. Lambs were sired by one of two rams with post-weaning FEC EBV of −9% or +9%. Mean FEC differed (p = 0.0132) with lambs from the lower EBV sire (“Sire L”) being reduced, versus those from the higher EBV sire (“Sire H”), being 2135 ± 211 vs. 2912 ± 207 eggs per gram, respectively. Males and females did not differ for FEC, but females exhibited a higher mean PCV than males, (33.74 vs. 29.65%, p < 0.0001). Lambs were shorn ~120 d post artificial infection and wool measurements were captured. A negative correlation between FEC and grease fleece weight was observed. Our results describe the response of Rambouillet lambs to artificial H. contortus infection and suggest FEC EBV can reduce susceptibility to GIN in this breed.
胃肠道线虫（GIN）威胁着全球绵羊的生产力和健康，这促使人们需要通过基因选择来降低对GIN的易感性。对感染寄生虫的兰布列绵羊的粪便虫卵计数（FEC）、红细胞压积（PCV）以及各种生产性状进行了检测，并与父系FEC估计育种值（EBV）进行了比较。给77只兰布列羔羊接种了10,000条捻转血矛线虫L3幼虫。随后，在六周内每隔七天记录一次FEC、PCV和体重（BW）。这些羔羊由两只公羊之一所生，这两只公羊断奶后的FEC EBV分别为-9%或+9%。平均FEC存在差异（p = 0.0132），来自EBV较低的父系（“父系L”）的羔羊的FEC较低，而来自EBV较高的父系（“父系H”）的羔羊的FEC较高，分别为每克2135±211个虫卵和2912±207个虫卵。FEC在雄性和雌性之间没有差异，但雌性的平均PCV高于雄性（33.74%对29.65%，p < 0.0001）。在人工感染后约120天给羔羊剪毛，并测量羊毛。观察到FEC与含脂羊毛重量之间呈负相关。我们的结果描述了兰布列羔羊对人工感染捻转血矛线虫的反应，并表明FEC EBV可以降低该品种对GIN的易感性。
