The effect on nitrogen utilization in the sow of variation in dietary protein concentration and pattern of feeding in pregnancy

Publisher Website
Google Scholar
Abstract
SUMMARY: In a factorial experiment, two protein concentrations and three patterns of feeding were administered to eighteen Large White × Wessex sows (three per treatment) in their second pregnancy. Treatments were repeated in their third pregnancy, when balance trials were conducted. The high protein diet (HP) (19·5% crude protein) contained 15% white-fish meal. The low protein diet (LP) (10·5% crude protein) contained protein of vegetable origin only. The pattern treatments involved intakes of 1·8 kg (L) 2·7 kg (C) and 3·6 kg (H) per day, the three pregnancy feeding patterns being HL, C and LH. Parturition results and lactation performance in the third reproductive cycle were similar to those recorded in the previous reproductive cycle (Pike & Boaz, 1969) reported earlier. Nitrogen retention in the third pregnancy was significantly higher in the HP sows(1606 g N)thaninthe LP sows(1082 g N) (P < 0·001). Intra-uterine nitrogen deposition in pregnancy was not affected by any of the treatments. Extra-uterine nitrogen deposition was significantly greater in the HP than the LP sows (P < 0·001). Dietary protein differences influenced extra-uterine rather than intra-uterine deposition of nitrogen in the pregnant sow, greater extra-uterine nitrogen deposition appearing to enhance subsequent lactation in this and the previous (Pike & Boaz, 1969) experiment. Protein utilization was more efficient in late than early pregnancy, suggesting that the feeding of higher levels of protein in late pregnancy should lead to greater efficiency over the whole pregnancy, provided energy intake is sufficient to promote optimum protein utilization.
Keywords