Nutritional Evaluation of Chinese Nonconventional Protein Feedstuffs for Growing-Finishing Pigs - 1. Linseed Meal

Two experiments were conducted to determine the ileal digestibility of the amino acids contained in linseed meal using the regression technique and then applying the values obtained, in a growth trial, using growing-finishing pigs. For the digestibility trial, four $20{\pm}0.5kg$ crossbred $(Yorkshire{\times}Landrace{\times}Beijing\;Black)$ barrows were fitted with simple T-cannula in the terminal ileum. After recovery, the barrows were fed one of four experimental diets according to a $4{\times}4$ Latin Square design. The pigs were fed corn-soybean meal based diets supplemented with 0, 25, 50 or 75% linseed meal. For the growth trial, 80 crossbred $(Yorkshire{\times}Landrace{\times}Beijing\;Black)$ growing pigs $(20.2{\pm}1.5kg)$ were fed corn-soybean meal diets supplemented with 0, 5, 10 or 15% linseed meal. Five pens (2 gilts and 2 castrates) were assigned to each treatment. With the exception of leucine, the digestibility coefficients for the indispensible amino acids declined as the level of linseed meal in the diet increased. There was a good agreement between the amino acid digestibilities for lysine, methionine, threonine and tryptophan determined using the regression technique and amino acid digestibilities previously published for linseed meal. During both the growing (20-49 kg) and finishing (49-95 kg) periods, the addition of linseed meal decreased average daily gain and feed conversion in a linear manner (p<0.05). Feed intake was not significantly different among treatments. The overall results suggest that linseed meal can be used at levels of between 5 and 10% in diets fed to growing-finishing pigs provided that the diet has been balanced for digestible amino acids.