Turner S P, Roehe R, Mekkawy W, Farnworth M J, Knap P W, Lawrence A B
Scottish Agricultural College, Sir Stephen Watson Building, Bush Estate, Penicuik, Midlothian EH26 0PH, UK.
Behav Genet. 2008 Jan;38(1):67-75. doi: 10.1007/s10519-007-9171-2. Epub 2007 Nov 7.
There is increasing interest in genetic selection against behavioural traits that impact negatively on welfare and productivity in commercial livestock production. Post-mixing aggressiveness in pigs shows wide phenotypic variation, affects health, welfare and growth performance and is a routine feature of production. A Bayesian approach was used to estimate the heritability of three traits associated with aggressiveness in pigs during the 24 h post-mixing; duration in reciprocal aggression, and in receipt of, or delivery of non-reciprocal aggression (NRA). For the purposes of genetic selection, recording aggressive behaviour is excessively labour intensive. The genetic correlations were quantified between the behavioural traits and an easily measurable indicator trait; the number of skin lesions following mixing (lesion score, LS). The heritabilities for the three behavioural traits ranged from 0.17 to 0.46 (receipt of NRA and reciprocal aggression respectively). The duration in reciprocal aggression and in delivery of NRA showed a strong genetic correlation (r g = 0.79 with 95% Bayesian credibility interval of 0.62-0.94). The genetic correlation between LS and these two behaviours indicated that selection on breeding values of LS could be used to reduce aggressiveness. The duration in receipt of NRA appeared to be regulated by different genes or genomic effects compared with the other behavioural traits and LS. Although duration in receipt of NRA was not genetically associated with LS, it was lowly but significantly environmentally associated with the residuals of central and caudal LS (r e = 0.28-0.32), indicating that pigs that received NRA also received bites on the central and caudal third of the body. The pen that the animals were mixed into was found to be a very important factor for the analysed traits, in particular those representing behavioural characteristics. Based on the estimated genetic parameters, it is concluded that selection on breeding values for reduced LS (especially central LS) is expected to reduce reciprocal aggression and the delivery of NRA but will not change the receipt of NRA directly.
在商业家畜生产中，针对那些对福利和生产力产生负面影响的行为特征进行基因选择，人们的兴趣日益浓厚。猪混群后的攻击性表现出广泛的表型变异，会影响健康、福利和生长性能，并且是生产中的常见特征。采用贝叶斯方法估计了猪混群后24小时内与攻击性相关的三个性状的遗传力；相互攻击的持续时间，以及遭受或实施非相互攻击（NRA）的持续时间。出于基因选择的目的，记录攻击行为的劳动强度过大。对行为性状与一个易于测量的指示性状——混群后皮肤损伤的数量（损伤评分，LS）之间的遗传相关性进行了量化。这三个行为性状的遗传力范围为0.17至0.46（分别为遭受NRA和相互攻击的遗传力）。相互攻击的持续时间和实施NRA的持续时间显示出很强的遗传相关性（rg = 0.79，95%贝叶斯可信区间为0.62 - 0.94）。LS与这两种行为之间的遗传相关性表明，对LS育种值进行选择可用于降低攻击性。与其他行为性状和LS相比，遭受NRA的持续时间似乎受不同基因或基因组效应的调控。尽管遭受NRA的持续时间与LS没有遗传关联，但它与躯干中部和尾部LS的残差存在低度但显著的环境关联（re = 0.28 - 0.32），这表明遭受NRA的猪在身体的躯干中部和尾部也受到了咬伤。发现动物被混群进入的围栏对于所分析的性状，特别是那些代表行为特征的性状来说是一个非常重要的因素。基于估计的遗传参数，得出结论：对降低LS（尤其是躯干中部LS）的育种值进行选择，有望减少相互攻击和NRA的实施，但不会直接改变遭受NRA的情况。
