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INFLUENCE OF ENERGY INTAKE DURING LACTATION ON THE INTERVAL FROM WEANING TO FIRST ESTRUS IN SOWS
Abstract
The research was divided into three phases. The objective of the first phase was to determine the influence of energy intake during lactation on the percentage of sows in estrus by 7, 14, 21 and 70 days postweaning. A total of 191 crossbred sows were used in three experiments Sows received 8 (Lo) or 16 (Hi) Mcal of metabolizable energy (ME)/day (Exp. 1 and 2) and 8 (Lo), 12 (Md) or 16 (Hi) Mcal of ME/d (Exp.3) during a 28-day lactation period. In Exp. 1 sows fed Lo lost more (P < .01) weight and backfat than sows fed Hi. Fewer sows fed Lo exhibited estrus (P (LESSTHEQ) 10) by 7, 14, 21 and 70 d postweaning than those fed Hi. In Exp. 2, similar results were observed, except that energy restriction decreased (P < .01) the percentage of sows in estrus by 7 days postweaning only. In Exp. 3 sow weight and backfat loss decreased (P < .01) linearly as energy intake increased. Fewer sows fed Lo expressed estrus (P (LESSTHEQ) .05) by 7, 14, 21 and 70 days postweaning than those fed Md or Hi. Sows fed Md and Hi did not differ. In the second phase, 44 second parity sows were used to determine the effect of energy intake during their first lactation (Lac 1) on subsequent reproductive performance. Sows from Exp. 1 (above) were mated and fed 5.4 Mcal of ME/day throughout the subsequent gestation period. Sows fed Lo during Lac 1 gained more (P=.10) weight, deposited more (P < .01) backfat during gestation, and farrowed lighter weight (P < .10) pigs than sows fed Hi. In the third phase, 45 primiparous sows were used to determine the relationship of the occurrence of postweaning estrus to (1) body fat (%), (2) lean body mass (LBM) and (3) qualitative characteristics of sow adipose tissue. Sows fed Lo that did not express estrus by day 14 postweaning had a similar fatty acid composition of their adipose tissue and LBM (as determined by urinary creatinine), but less (P < .05) body fat (%) than those fed Lo that did return to estrus by day 14 postweaning. The data indicate that catabolsm of body fat rather than muscle tissue was apparently more deleterious to a rapid return to estrus and that the lack of estrous activity by day 14 postweaning cannot be explained by differences in the fatty acid composition of outer subcutaneous adipose tissue.
Subject Area
Livestock
Recommended Citation
REESE, DUANE EUGENE, "INFLUENCE OF ENERGY INTAKE DURING LACTATION ON THE INTERVAL FROM WEANING TO FIRST ESTRUS IN SOWS" (1983). ETD collection for University of Nebraska-Lincoln. AAI8318675.
https://digitalcommons.unl.edu/dissertations/AAI8318675