Genetic parameters and phenotypic trends in the mean and variability of number of stillborn piglets and changes in their relationships with litter size and gestation length
Genetic parameters and phenotypic trends in the mean and variability of number of stillborn piglets and changes in their relationships with litter size and gestation length
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DOI：
10.1071/an12202
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发表时间：
2013-01-01
影响因子：
1.4
通讯作者：
Hermesch, Susanne
中科院分区：
文献类型：
--
作者：
Lewis, Craig R. G.;Hermesch, Susanne
本研究探讨了影响死胎仔猪（SB）的遗传和表型因素的变化。15年来，从大白色（LW）、长白猪（LR）和杜洛克（DU）母猪中获得了76851窝记录，以调查SB。分析重点是SB随时间的趋势和每窝SB数量的变化，与SB相关的因素和SB的遗传参数。品种差异被确定为DU比白色品种产生更多SB（平均值为1.46 +/- 0.02 vs 1.11 +/- 0.01和1.07 +/- 0.01）。然而，每个因素水平之间的最大差异分别为0.73和0.65 SB的奇偶校验和牛群。在研究的15年中，SB增加了0.2头仔猪，伴随着每窝出生的仔猪总数（TB）增加，接近0.5头仔猪。SB的增加是由单窝中两个以上SB的发生率较高所致。TB对SB的影响随时间变化，1996年和2010年的解决方案分别为0.127 +/- 0.002和0.150 +/- 0.002 SB/TB。对于替代模型和时间段，SB的遗传力估计值范围为0.06 +/- 0.01至0.09 +/- 0.01。基于所有可用数据，SB和TB之间的不利遗传相关性为0.46 +/- 0.03，仅使用前5年的数据（0.38 +/- 0.07）略低于使用最近5年的数据（0.46 +/- 0.06）。然而，随着时间的推移，SB和TB之间的表型和遗传关联的这种增加可能在观察到TB大量增加的人群中更大。
This study examined changes in genetic and phenotypic factors affecting stillborn piglets (SB). Over 15 years, 76 851 litter records were available from Large White (LW), Landrace (LR) and Duroc (DU) sows to investigate SB. The analyses focussed on trends over time in SB and the changes in the number of SB per litter, in factors associated with SB and in genetic parameters for SB. Breed differences were identified with DU producing more SB than the white breeds (mean of 1.46 +/- 0.02 vs 1.11 +/- 0.01 and 1.07 +/- 0.01). However, maximum differences between levels of each factor were 0.73 and 0.65 SB for parity and herd, respectively. Over the 15 years studied, SB had increased by 0.2 piglets accompanied by an increase in the total numbers of piglets born per litter (TB) of similar to 0.5 piglets. This increase in SB was driven by higher occurrence of more than two SB within a single litter. The effect of TB on SB changed over time with solutions of 0.127 +/- 0.002 and 0.150 +/- 0.002 SB/TB in 1996 and 2010, respectively. Heritability estimates for SB ranged from 0.06 +/- 0.01 to 0.09 +/- 0.01 for alternative models and time periods. The unfavourable genetic correlation between SB and TB of 0.46 +/- 0.03 based on all data available was slightly lower using only data from the first 5 years (0.38 +/- 0.07) versus using data from the last 5 years (0.46 +/- 0.06). However, this increase in phenotypic and genetic associations between SB and TB over timemaybe larger in populations that have observed a larger increase in TB.