Effect of a Low-Protein Diet during Mid-to-late Gestation on Reproductive Performance and Serum Amino Acid Profiles in Sows

Lay Summary The development of the pig industry has led to an increase in protein feed consumption and nitrogen excretion. The aim of this study is to figure out whether an appropriate low-protein diet in pregnant sows could impair their reproductive performance and decrease nitrogen excretion. Sows were divided into two groups, and were fed with normal gestational diet (crude protein = 13.65%) or a low-protein gestational diet (crude protein = 11.30%, and supplemented with limiting amino acids) from day 30 of gestation to the day before parturition. Results showed that the number and body weight of born alive piglets were similar between the two groups. Besides, the low-protein diet decreased nitrogen excretion and serum concentrations of some amino acids, such as valine, arginine, lysine, and methionine, without changing the deposition rate of nitrogen in pregnant sows. The findings indicate that implementing a low-protein diet supplemented with limiting amino acids during mid-to-late gestation is a viable nutritional strategy for reducing both protein feed consumption and nitrogen excretion in sows, while maintaining reproductive performance.