The influence of different protein and energy levels and ratios in the diet of the reproducing sow:
A total of 64 Landrace gilts, initially between seven and eight months old, were used to study the effect of two dietary energy levels (each at two protein intake levels) in pregnancy, and a single energy level (at two protein intake levels) in lactation, on the productivity of the sow measured over three consecutive reproduction cycles. The reproductive ability of the sow was not affected by the protein or energy levels fed in this study. An increase in energy (feed) intake resulted in increased gains in live mass and body fat deposition in the sow. Increased intakes of both energy and protein did however have a disadvantageous effect on the efficiency with which ingested feed and protein was utilized for weaner production (kg mass at weaning). The results achieved therefore suggest that feed and protein levels for reproducing sows need not exceed the minimum levels fed used in this experiment.