Takai Y, Koketsu Y
School of Agriculture, Meiji University, Tama-ku, Kawasaki 214-8571, Japan.
Theriogenology. 2007 Jul 1;68(1):87-92. doi: 10.1016/j.theriogenology.2007.02.014. Epub 2007 May 23.
At-risk female pigs were defined as females having characteristics of at least one of the four subgroups: females with reservices, lactation length (LL) 0-13 days, weaning-to-first-mating interval (WMI) > or = 8 days, and abortion records. These females may have suboptimal reproductive performance. This study examined reproductive performance in at-risk females, and the relationships between at-risk females, parity, season of mating, and the four subgroups. From 117 farms, 102,494 parity records were categorized into at-risk females and non-at-risk females. Statistical mixed models were used to analyze reproductive performance. Of the 102,494 records, 19.6% were at-risk females. At-risk females had at least 11.1% lower farrowing rates than non-at-risk females among all parities and seasons of mating (P<0.05). As parity increased from 1 to > or = 6, farrowing rate in at-risk females decreased from 74.1 to 62.9%, while the farrowing rate in non-at-risk females decreased from 87.3 to 82.0% (P<0.05). There was no difference in the number of pigs born alive between at-risk females and non-at-risk females (P=0.810). Females at Parity 1 and those that mated during summer had the highest proportion of becoming at-risk females (P<0.001). Gilts and sows with abortion records had at least 39.3% lower farrowing rates than those with non-abortion records (P<0.001). Among the LL 0-13 days, the farrowing rate was below 70% regardless of WMI. Monitoring and reducing at-risk females is an opportunity for producers to improve herd productivity.
有再次配种情况的母猪、泌乳期长度（LL）为0 - 13天的母猪、断奶至首次配种间隔（WMI）≥8天的母猪以及有流产记录的母猪。这些母猪的繁殖性能可能欠佳。本研究考察了高危母猪的繁殖性能，以及高危母猪、胎次、配种季节和四个亚组之间的关系。从117个猪场收集的102,494条胎次记录被分为高危母猪和非高危母猪。采用统计混合模型分析繁殖性能。在这102,494条记录中，19.6%为高危母猪。在所有胎次和配种季节中，高危母猪的产仔率比非高危母猪至少低11.1%（P<0.05）。随着胎次从1增加到≥6，高危母猪的产仔率从74.1%降至62.9%，而非高危母猪的产仔率从87.3%降至82.0%（P<0.05）。高危母猪和非高危母猪的活产仔猪数没有差异（P = 0.810）。第1胎的母猪以及在夏季配种的母猪成为高危母猪的比例最高（P<0.001）。有流产记录的后备母猪和经产母猪的产仔率比无流产记录的母猪至少低39.3%（P<0.001）。在泌乳期长度为0 - 13天的情况下，无论断奶至首次配种间隔如何，产仔率均低于70%。监测和减少高危母猪数量是养殖者提高猪群生产力的一个契机。
