分娩与断奶背膘厚度对猪繁殖性能的影响研究

为研究母猪分娩与断奶时背膘厚度对繁殖性能的影响，使用A超测定母猪分娩及断奶时的背膘厚度，根据分娩时背膘厚度将试验动物分为1组（X＜10 mm）、2 组（10 mm≤X≤14 mm）、3 组（X＞14 mm）,根据断奶时背膘厚度将试验动物分为A组（X＜7 mm）、B组（7 mm≤X＜10 mm）、C组（10 mm≤X＜13 mm）、D组（13 mm≤X＜16 mm）、E组（X≥16 mm），又根据母猪哺乳期间损失的背膘厚度分为Ⅰ组（X＜3 mm）、Ⅱ组（3 mm≤X≤6 mm）、Ⅲ组（X＞6 mm），用方差分析比较各组繁殖表现，并建立了发情间隔对背膘厚度的回归方程。结果表明，分娩时产死胎母猪的比例2组是10.5%，在3组中最小；断奶后平均发情间隔C组显著低于其他各组(P＜0.05)；哺乳期间背膘损失最大的Ⅲ组母猪平均发情间隔为8 d,显著高于Ⅰ组、Ⅱ组(P＜0.05)。表明分娩与断奶背膘厚对母猪繁殖性能有显著影响，膘情适中的母猪有最好的繁殖表现，并建立了回归方程Y=31.787－6.169X +0.440X²－0.009X³，用于预测母猪发情配种日期。

Study on Influence of Sows’ Backfat Thickness at Farrowing and Weaning on Reproductive Performance

This experiment was aimed to reveal the effects of sows’ backfat thickness at farrowing and at weaning on reproductive performance. The backfat thickness at farrowing and at weaning was determined by type-A ultrasonic device. According to the backfat thickness at farrowing, sows were divided into group 1 （<10 mm）, group 2 （10～14 mm）,group 3 （>14 mm）;According to the backfat thickness at weaning, sows were divided into group A （<7 mm）, group B （7～10 mm）, group C （10～13 mm）,group D （13～16 mm）,group E （>16 mm）；According to the loss of backfat thickness during the lactation period, sows were divided into group Ⅰ（<3 mm），group Ⅱ（3～6 mm） and group Ⅲ（>6 mm）. The results showed that the rate of sows producing stillbirth was 10.5% in group 2, which was the least in the three groups, and the average weaning-estrus interval of group C was significantly shorter than other groups （P<0.05）. During the lactation period, the loss of back fat thickness in group Ⅲ was higher than groupⅠand groupⅡevidently, and the average estrus interval of group C was also markedly higher than groupⅠand groupⅡ （P<0.05）. The study indicated that sows with medium backfat thickness at farrowing and weaning shown the best reproduction performance. And an regression equation was established to forecast estrus date based on backfat thickness at weaning: Y=31.787－6.169X＋0.440X²－0.009X³.