Influence of Energy Intake during Lactation on the Interval from Weaning to Firts Estrus in Sows

Abstract

A total of 191 crossbred sows were used to determine the effect of energy intake during one lactation on (1) sow and pig performance and (2) the percentage of sows in estrus by 7, 14, 21 and 70 d postweaning. Sows received 8 (Lo) or 16 (Hi) Mcal of metabolizable energy (ME)/d (Exp. 1 and 2) and 8 (Lo), 12 (Md) or 16 (Hi) Mcal of Me/d (Exp. 3) during a 28-d lactation period. All sows were fed an equal amount of crude protein, vitamins and minerals that met or exceeded the recommendations of the National Research Council. Each day after weaning, sows were fed 1.8 kg of a 14% crude protein diet and checked for estrus using boars. Serum samples were obtained weekly from sows not detected in estrus by 15 d postweaning for progesterone analysis. In Exp. 1 sows fed Lo lost more (P less than .01) weight and backfat, and weaned lighter weight (P less than .01) pigs than sows fed Hi. Fewer sows fed Lo exhibited estrus (P less than .01) by 7, 14, 12 and 70 d postweaning than sows fed Hi. In Exp. 2, sows fed Lo lost more (P less than .01) weight and backfat than sows fed Hi, but pig weaning weights did not differ. Fewer sows fed Lo expressed estrus by 7 d (P less than .01) postweaning than those fed Hi. In Exp. 3 sow weight and backfat loss decreased (P less than .01) linearly as energy intake increased. Pig weaning weights were not affected by energy intake. Fewer sows fed Lo expressed estrus (P less than or equal to .05) by 7, 14, 21 and 70 d postweaning than those fed Md and Hi. There was no difference in the percentage of sows fed Md or Hi that exhibited estrus by these time periods. Blood samples collected on d 110 of gestation and d 14 and 26 of lactation, indicated that energy intake did not influence hematocrit values, total serum protein or albumin concentrations. A significant energy intake by time interaction was observed for serum blood urea N. Three of the 25 sows bled for progesterone analysis had luteal tissue activity suggesting ovulation had occurred even in the absence of a detected behavioral estrus.

Feeding lactating primiparous sows to establish three divergent metabolic states: I. Associated endocrine changes and postweaning reproductive performance.

“…Hence, almost all of the additional nutrients available to the sows were directed toward tissue anabolism (see Clowes et al, 1998 for further discussion) and could have potentially ameliorated any inhibitory effects of lactational catabolism on reproductive performance. Consistent with the data reported by Nelssen et al (1985), Mullan and Williams (1989), and Koketsu et al (1996), restriction of feed intake during lactation seemed to decrease litter weight at weaning and extended the weaning-to-estrus interval (Reese et al, 1982;Mullan and Williams, 1989). Despite the increase in body weight and backfat during lactation, the fertility of SA sows was not different from that of Table 3.…”

“…In contrast, although the weaning-toestrus interval was not different between AL and SA sows, when estrus occurred SA sows were in a negative energy balance. If the situation between weaning and estrus was analogous to that of lactation, a sow approaching a more catabolic state would be expected to exhibit an extended weaning-to-estrus interval (Reese et al, 1982;Armstrong et al, 1986;Koketsu et al, 1996). However, data from King and Williams (1984) have shown that the weaning-toestrus interval cannot be reduced by additional feed consumption after weaning, and conversely, restriction of feed intake after weaning in sows that were fed 6 kg during lactation did not extend the time to return to estrus (Baidoo et al, 1992).…”

Effects of dietary energy and lysine intake during late gestation and lactation on blood metabolites, hormones, milk compositions and reproductive performance in primiparous sows

“…In the present study, the intake of nutrients had a significant effect on WEI. Sows supplied with 71 MJ DE daily had a significantly shorter wean-to-estrus period than sows provided with 35 MJ DE daily (Reese et al 1982). x E 0energy main effect, L 0lysine main effect, E )L 0energy)lysine interaction.…”

Effect of Sows’ Condition on Morphological and Biochemical Blood Indicators

“…Reese et al [15] did not find any effect of energy intake together with the feed on haematocrit value but they observed its differentiation between pregnancy and lactation.…”