Energy Values of Wheat Bran Are Additive in Corn-Soybean Meal-Based Swine Diets

The objective of this experiment was to verify the additivity of energy value of wheat bran (WB) in corn-soybean meal (SBM)-based diets fed to pigs. Four experimental diets based on the corn and SBM were formulated to contain 0, 10, 20, or 30% of WB with the constant ratio of corn and SBM at 3.4:1. Eight crossbred barrows with a mean initial BW of 63.1 kg ± 3.4 were individually housed in metabolism crates equipped with a feeder. The animals were allocated to a replicated 4 × 4 Latin square design with 4 diets, 4 periods, and 8 pigs. Each period consisted of a 4-d adaptation period to the experimental diet and a 4-d collection period. Feces were collected using the marker-to-marker procedure and urine was collected from 1400 on d 5 to 1400 on d 9 of each period. The daily fecal output and daily fecal energy output linearly increased (P < 0.001) with WB inclusion rate. The DE:GE linearly decreased (P < 0.001) as WB inclusion rate increased. As dietary WB increased, the DE and ME values of the experimental diets linearly decreased (P< 0.001) without quadratic effect. Based on the linear changes of DE and ME values with WB inclusion rate, we conclude that the DE and ME values of WB are additive up to 30% inclusion rate in corn-SBM-based diets fed to pigs.

Table 1. Energy values of experimental diets fed to pigs, as-fed basis

	Wheat bran, %				SEM	P-values
Item	0	10	20	30		Linear	Quadratic
Diet DE, kcal/kg	3,667	3,592	3,551	3,493	32	< 0.001	0.794
DE:GE	0.919	0.895	0.879	0.861	0.008	< 0.001	0.698
Diet ME, kcal/kg	3,613	3,542	3,494	3,431	34	< 0.001	0.909
ME:DE	0.985	0.986	0.984	0.982	0.001	0.077	0.364