THE EFFECTS ON LITTER SIZE OF PREVIOUS LACTATION LENGTH AND PREVIOUS WEANING-TO-CONCEPTION INTERVAL IN ONTARIO SWINE

被引:34
作者
DEWEY, CE [1 ]
MARTIN, SW [1 ]
FRIENDSHIP, RM [1 ]
WILSON, MR [1 ]
机构
[1] UNIV GUELPH,ONTARIO VET COLL,DEPT POPULAT MED,GUELPH N1G 2W1,ONTARIO,CANADA
关键词
D O I
10.1016/0167-5877(94)90077-9
中图分类号
S85 [动物医学(兽医学)];
学科分类号
0906 ;
摘要
Lactation length and the weaning-to-conception interval are two key features of reproductive efficiency. A retrospective study of 112 Ontario swine farms was conducted to determine the association between litter size and previous lactation lengths up to 40 days and previous weaning-to-conception intervals up to 14 days. Threshold dummy variables were created for lactation lengths between 14 days and 40 days and for weaning-to-conception intervals up to 14 days. The litter size increased progressively at previous lactation lengths of 20, 25, 27 and 33 days (P<0.05). Sows bred on Days 2-4 post weaning had essentially the same litter size. Litter size decreased progressively for sows bred on Days 5, 6, and 7 post weaning and then reached a plateau until it increased again for sows bred on Day 11 or later (P<0.05).
引用
收藏
页码:213 / 223
页数:11
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