Determination of the apparent ileal digestibility of protein and amino acids in feedstuffs and mixed diets for growing-finishing pigs with the mobile nylon bag technique
Yin, Y.L.; Zhong, H.Y.; Huang, R.L.
Asian-Australasian Journal of Animal Sciences 8(5): 433-441
A series of experiments was conducted to determine the influence of various pepsin-HCL pretreatment factor, hereby the factors of duration of washing for the retrieved bags, inherent to the mobile nylon bag technique (MNBT), on apparent ileal digestibility of crude protein (AIDCP) and apparent ileal digestibility of dry matter (AIDDM). At last, the AIDCP and apparent ileal digestibility of amino acids (AIDAA) in maize, barley, wheat, rapeseed meal, cottonseed meal and three mixed diets were determined with the MNBT and ileo-rectal anastomis pigs (IRAT). For the MNBT techniques, bag measuring 25 times 40 MM and containing 0.75 g feedstuff samples, after pre-digestion in vitro, were introduced into the ileo-rectal anastomis pigs (IRAT) gastrointestinal tract through a duodenal cannula and recovered in the ileal digesta between 6 and 12 h. later. 1. The apparent ileal digestibility of dry matter (AIDDM) and crude protein (AIDCP) of the tested samples, with the exception of fish meal, determined by MNBT were not affected by the different pepsin-HCL pretreatment times in vitro between 2.5 h. and 4 h 2. There was no significant (p gt 0.05) difference of the AIDCP and AIDDM of maize determined by the MNBT among different pepsin concentration (0.03%, 0.07% and 0.1%) treatment in vitro. 3. The AIDCP determined with the NNBT was affected by the washed and unwashed recovered bags from the ileal digesta. 4. The AIDCP and AID amino acids (AIDAA) of maize, barley, wheat, rapeseed meal, soya-bean meal, cottonseed meal and three mixed diets from the MNBT, with a solution of 0.01 N HCL (PH 2) and 0.1% of pepsin concentration, a pepsin-HCL pretreatment time in vitro or 4 h. and a washing time of the recovered bag from the ileal digesta compared well with those from the IRAT. The linear regression analysis showed a significant correlation (p lt 0.01) of AIDCP and AIDDA between the IRAT and MNBT.