Tantasuparuk W, Dalin A, Lundeheim N, Kunavongkrit A, Einarsson S
Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, SE-750 07, Uppsala, Sweden.
Anim Reprod Sci. 2001 Mar 30;65(3-4):273-81. doi: 10.1016/s0378-4320(00)00218-9.
The aim of this study was to investigate the ovulation rate and the weaning-to-service interval (WSI) of sows in relation to their body weight loss during lactation in tropical climatic conditions. Effect of lactation length (LL), number of total born piglets, number of live born piglets, litter birth weight, average piglet birth weight, number of pigs weaned, litter weaning weight and average pig weaned weight on sow weight loss during lactation were also studied. This study was conducted in two commercial purebred sow herds (A, B) in the central part of Thailand from August to December 1997. The herds had both Landrace (L) and Yorkshire (Y) sows. The 123 sows (55 L and 68 Y) in herd A and 153 sows (95 L and 58 Y) in herd B, parity 1-4, were weighed within 4 days after farrowing and at weaning. Lactation length, litter size at birth and at weaning, litter weight at birth and at weaning, and WSI were recorded for each of these sows. In herd A, 52 sows (20 L and 32 Y) were examined once by laparoscopy between days 8 and 14 after AI-service. These sows had farrowed at least seven piglets in the previous parturition. The numbers of corpora lutea (CL) in both ovaries were counted, and were assumed to equal the ovulation rate. L-sows had significantly (P < 0.05) higher relative weight loss during lactation (RWL) than Y-sows. The RWL increased by 0.7% for each extra pig weaned. When LL increased by 1 day, within the interval of 17-34 days, RWL decreased by 0.6%. Sows with a high weight loss had significantly (P < 0.05) longer WSI than sows with medium or low weight loss. Weight loss had a significant (P < 0.05) effect on WSI in parity 1 and 2 sows. Y-sows had more CL than L-sows (15.7 versus 14.0) (P < 0.05). RWL, parity and regression on lactation length had no significant effect on number of CL. In conclusion, sows with higher number of pigs weaned lose more weight. Under the restricted feeding regime applied, high weight loss during lactation prolongs WSI in parity 1 and 2 sows, but has no influence on the ovulation rate at first oestrus after weaning. The ovulation rate is higher in Yorkshire than in Landrace sows. The ovulation rate is independent of parity.
本研究旨在调查热带气候条件下母猪的排卵率以及断奶至配种间隔（WSI）与泌乳期体重损失之间的关系。同时还研究了泌乳期长度（LL）、总产仔数、活产仔数、窝出生体重、平均仔猪出生体重、断奶仔猪数、窝断奶体重和平均断奶仔猪体重对母猪泌乳期体重损失的影响。本研究于1997年8月至12月在泰国中部的两个商业纯种母猪群（A、B）中进行。这些猪群既有长白猪（L）也有大白猪（Y）。A群中的123头母猪（55头L和68头Y）以及B群中的153头母猪（95头L和58头Y），胎次为1至4胎，在分娩后4天内和断奶时称重。记录每头母猪的泌乳期长度、出生时和断奶时的窝仔数、出生时和断奶时的窝体重以及WSI。在A群中，52头母猪（20头L和32头Y）在人工授精配种后第8至14天通过腹腔镜检查一次。这些母猪在前一次分娩时至少产了7头仔猪。统计两侧卵巢中的黄体（CL）数量，并假定其等于排卵率。长白母猪在泌乳期的相对体重损失（RWL）显著高于大白母猪（P < 0.05）。每多断奶一头仔猪，RWL增加0.7%。当LL在17至34天的区间内增加1天时，RWL下降0.6%。体重损失高的母猪的WSI显著长于体重损失中等或低的母猪（P < 0.05）。体重损失对第1和第2胎次母猪的WSI有显著影响（P < 0.05）。大白母猪的CL比长白母猪多（15.7对14.0）（P < 0.05）。RWL、胎次和泌乳期长度回归对CL数量无显著影响。总之，断奶仔猪数较多的母猪体重损失更多。在采用的限饲制度下，泌乳期体重损失高会延长第1和第2胎次母猪的WSI，但对断奶后首次发情时的排卵率没有影响。大白母猪的排卵率高于长白母猪。排卵率与胎次无关。
