抗病育种是一个具有挑战性但日益必要的目标,以克服减少抗生素使用和对动物福利日益关注的问题,同时限制经济损失。然而,实施这些策略是一个复杂的过程,因为动物面临许多疾病,选择农场的环境与商业农场的环境不同。我们评估了是否可以基于选择(S)和挑战性(Ch)环境中的单个视觉记录选择对非特异性疾病的抗性。这项研究使用了2012年至2016年出生的23,773只纯种兔子的记录。断奶后(32日龄),在S环境中饲养了17,712只兔子,在Ch环境中饲养了6,061只同胞。在测试结束时记录所有动物的疾病临床体征。在一个时间点,在70或80天的年龄。还记录了在测试结束之前发生的死亡原因。分析了三个疾病特征:呼吸道疾病的体征,消化系统疾病的迹象,以及考虑到消化迹象的复合特征(抵抗),呼吸道和各种传染病。提出后一种复合性状以捕获对疾病的全球抗性。所有疾病特征都是二元的,0表示没有症状。还记录了两个生产特征:活产的试剂盒数量(4,121窝)和断奶重量(13,090只兔子)。用动物阈值模型分析疾病性状,假设特征在两种环境中是不同的。使用线性动物模型进行双变量分析。疾病性状的遗传力范围为0.04±0.01至0.11±0.03。两种环境中疾病性状之间的遗传相关性均低于1(≤0.84),通过环境相互作用指示基因型。大多数疾病和生产性状之间的遗传相关性没有显着差异为零,除了断奶重量和抵抗S之间,具有-0.34±0.12的有利相关性。鉴于这些遗传参数,对于相同水平的兔子暴露于病原体,对选择的预期反应是每代疾病发病率降低4-6%.
Breeding for disease resistance is a challenging but increasingly necessary objective to overcome the issues with the reduced use of antibiotics and growing concern for animal welfare while limiting economic losses. However, implementing such strategies is a complex process because animals face numerous diseases, and the environments on selection farms differ from those on commercial farms. We evaluated whether selection for resistance to non-specific diseases based on a single visual record in selection (S) and challenging (Ch) environments is possible. Records from 23,773 purebred rabbits born between 2012 and 2016 were used in this study. After weaning (at 32 days of age), 17,712 rabbits were raised in the S environment and 6,061 sibs were raised in the Ch environment. Clinical signs of disease were recorded for all animals at the end of the test, at a single time point, at 70 or 80 days of age. The causes of mortality occurring before the end of the test were also recorded. Three disease traits were analyzed: signs of respiratory disease, signs of digestive disease, and a composite trait (Resist) taking into account signs of digestive, respiratory and various infectious diseases. This latter composite trait is proposed to capture the global resistance to disease. All disease traits were binary, with 0 being the absence of symptoms. Two production traits were also recorded: the number of kits born alive (4,121 litters) and the weaning weight (13,090 rabbits). Disease traits were analyzed with animal threshold models, assuming that traits are different in the two environments. Bivariate analyses were carried out using linear animal models. The heritabilities of the disease traits ranged from 0.04 ± 0.01 to 0.11 ± 0.03. The genetic correlations between disease traits in both environments were below unity (≤ 0.84), indicating genotype by environment interactions. Most of the genetic correlations between disease and production traits were not significantly different from zero, except between the weaning weight and Resist_S, with a favorable correlation of -0.34 ± 0.12. Given these genetic parameters, for the same level of exposure of rabbits to pathogens, the expected response to selection is a reduction of disease incidence of 4-6% per generation.