Objective: The primary objective of this study is to examine the metabolic effects of soy-based protein as a replacement for carbohydrate on highly-prolific sows at parturition. The project evaluated the effects of higher levels of SBM and Met as a replacement for corn, the primary carbohydrate source, and crystalline AA, focusing on their impact on markers of sow health during the peri-parturition and lactation periods.
Results and Discussion: The average total born, liveborn, and weaned pigs were 15.7, 14.2, and 12.8 respectively, which are data representative of the current level of prolificacy (Eckberg, 2022). Sows on the high SBM diets had less weight fluctuation throughout the trial period and came out of lactation with an average of 5.8 kg lost while the low soy group lost an average of 12.9 kg (P = 0.1262). The level of Met also improved the change in sow BW through lactation. Sows on high Met lost 4.7 kg while the sows on low Met lost 14.5 kg (P < 0.05). The combined effect of high SBM and high Met produced an average lactation weight change of +1.9 kg while the low SBM and low Met TRT, similar to NRC recommendations (2012), had an average of -18.9 kg (P = 0.0588). The 30% Met group also lost less BF during lactation (P < 0.01). No statistical differences were observed for feed intake, gestation duration, total pigs born, liveborn, or pigs weaned due to TRT. An elevation of blood glucose pre- and post-farrowing in sows fed more starch and synthetic amino acids with a lower methionine level was not beneficial to farrowing performance. To the contrary, sows fed higher levels of intact soy protein had increased pig weaning weight and improved recovery from parturition, as indicated by reduced body weight loss. The use of continuous glucose monitors in sows at farrowing was successfully piloted and revealed dynamic glucose metabolism changes at farrowing. Glucose was slightly elevated in sows post farrowing when fed higher levels of starch, amino acids and the 27% met:lysine. Sows fed higher soy protein levels (30% SBM) appear to be able to utilize protein very efficiently for energy at farrowing compared to 15% SBM.
Conclusion: Peripartum health complications, including farrowing difficulty, contribute to the need for greater care of HPS. The higher inclusion of SBM and Met to sow diets improves sow condition and health outcomes. In HPS, the use of intact soy protein from soybean meal, resulted in better farrowing and lactation performance than starch with synthetic amino acids. Additional commercial research is planned to evaluate a higher plane of nutrition provided by intact soy protein and farrowing ease, nutritional state, and sow mortality. Intact soy protein, balanced with a higher ratio of methionine:lys than NRC recommendations, is recommended for late gestation and lactation diets.