The response of lactating sows and their litters to different dietary energy allowances. 1. Milk yield and composition, reproductive performance of sows and growth rate of litters

Abstract

SUMMARYTwenty-four gilts were used at each of two centres in an experiment designed to examine the effects of dietary energy intake during lactation on yield and composition of sows' milk and the growth of their litters. Gestation feed intake was standardized at 2 kg per day supplying 6·28 Meal digestible energy (DE) and 280 g crude protein. The energy levels fed during lactation ranged from 12·2 to 18·25 Meal DE per day for gilts, 12·9 to 19·6 Meal DE per day for second parity and from 13·2 to 20·25 Meal DE per day for third parity sows. Daily crude protein intake and amino acid balance ofthe protein were kept constant.In the first lactation milk yield and composition and growth of litters were not influenced by dietary energy intake. In the second lactation milk yield was depressed by lower energy intakes and this was reflected in litter weights at 21 though not at 42 days. In the third lactation lower energy intakes seriously depressed milk yield and daily output of milk nutrients. On the lowest level of energy, milk yield was 32% lower at day 24 and 20% lower at day 41 of lactation than on the highest energy level. The corresponding depressions in litter weights were 17·2 and 13·5% at 21 and 42 days respectively.

Influence of Energy Intake during Lactation on Subsequent Gestation, Lactation and Postweaning Performance of Sows

“…These results agree with those of Elsley et al (1968), O'Grady et al (1975) and Reese et al (1982). Average litter size at weaning was not affected by energy intake which also agrees with previous reports (Elslcy et al, 1968;O'Grady et al, 1973;Reese et al, 1982).…”

“…Studies by Elsley et al (1968), O'Grady et al (1973), Adam and Shearer (1975) disagree; however, the pigs in the previous studies received creep feed that may have masked differences in pig weaning weights. Reese et al (1982) reported that the effect of energy intake during lactation on pig weaning weight was variable.…”

“…Elsley et al (1968) and Adam and Shearer (1975) reported that energy intake during the previous lactation had no influence on the number of pigs born and average pig birth weight. Feed intake during lactation also had no influence on litter size at birth Hitchcock et al, 1971;Varley and Cole, 1976) and birth weight O'Grady et al, 1973;Varley and Cole, 1976). O'Grady et al (1973) reported that the number of pigs born alive decreased as energy intake increased during the previous lactation.…”

“…Feed intake during lactation also had no influence on litter size at birth Hitchcock et al, 1971;Varley and Cole, 1976) and birth weight O'Grady et al, 1973;Varley and Cole, 1976). O'Grady et al (1973) reported that the number of pigs born alive decreased as energy intake increased during the previous lactation.…”

“…Elsley et al (1968), O'Grady et al (1973) and Adam and Shearer (1975) determined that the interval from weaning to first estrus was not affected when sows were fed 12 to 20 Meal of digestible energy daily during three or more lactations. Reese et al (1982) reported that energy intake during one lactation had a marked influence on the subsequent interval from weaning to first estrus.…”