Effects of supplemental betaine isolated or in combination with soybean hulls on growth performance, body composition, and metabolic status of young growing pigs.

To study the interaction between betaine (BET) and soybean hulls (SBH) on growth performance, body composition, and metabolic status of young growing pigs, 24 barrows with initial body weight (BW) of 29.51 ± 3.24 kg were allotted to one of four dietary treatments in a 2 × 2 factorial arrangement with two levels of BET (0 and 1 g/kg) and SBH (0 and 150 g/kg) for 28 days. Pig BW and feed disappearance were recorded at 14-day intervals. Real-time ultrasonic measurements, as well as jugular blood samples, were obtained initially and on day 28 for all pigs. There was no SBH x BET interaction for growth responses. Pig growth was unaffected by BET supplementation. Dietary SBH addition decreased (P < 0.001) growth rate, as well as feed and energy intakes, which resulted in lighter pigs (P < 0.01) at the end of the study. The inclusion of BET in diets without SBH increased (P < 0.05) loin area and fat-free lean gain, whereas the dietary addition of SBH decreased (P ≤ 0.038) body protein and fat contents. Dietary BET supplementation did not impact the metabolic status of pigs, but feeding SBH increased globulin content (P = 0.039) and decreased albumin-to-globulin ratio (P = 0.023). In conclusion, adding supplemental BET to diets with SBH did not alter nutrient partitioning in young growing pigs, but feeding 150 g/kg SBH lead to slow growth rates and metabolic inefficiency.