Effect of Gestation Dietary Crude Protein Level on the Gestation and Lactation Performance of Primiparous Sows

Purdue University 1998 Swine Research Report. Gestation is an especially demanding phase of production for the gilt because of the dual energy demands of body maturation (growth of muscle and fat reserves) and growth of the components of pregnancy (Pettigrew and Yang, 1997). Modern sow genotypes have an increased potential for lean gain and large litter size, and this makes an adequate supply of dietary amino acids critical for maximum reproductive efficiency. Currently, it is common to feed one 12 to 13% crude protein (CP) gestation diet, often at the same level of feed intake for the entire duration of gestation. This may prove adequate for gestating sows, but it does not appear to be adequate for gestating gilts to express their reproductive potential. Recent research has confirmed the benefits of dietary CP levels in excess of NRC (1988) recommendations. Gilts fed higher levels of CP during gestation (16 vs. 13%) had increased litter weight gains and litter weaning weights (Mahan, 1998). Increased CP (16 g/day lysine) improved primiparous sow milk production and litter weight gain (Kusina et al., 1995). Dietary protein level during gestation can also affect sow body fat content at term and feed intake during the subsequent lactation. Energy demands are greatest during the last 2 to 3 weeks of gestation, and gilts are often forced to mobilize body reserves at this time to meet their increasing energy demands. The objectives of this study were to 1) determine the effect of a two step increase in CP and a single step increase in CP and energy on gilt growth during gestation and reproductive performance during the subsequent lactation. We also wanted to 2) measure the levels of circulating metabolites and metabolic hormones to determine the impact of our dietary treatments on energy balance and body reserve mobilization during gestation and lactation in the gilt.