A comparison of methods to determine amino acid availability of feedstuffs in cecectomized ganders.
Experiments were conducted to compare endogenous amino acid losses and the true amino acid availability (TAAA) of 3 feedstuffs by using methods involving a short-term fasting and an N-free diet with cecectomized ganders. Diets were formulated to contain soybean meal, fish meal, and cottonseed meal as the sole source of protein. A precision-fed assay was used in which each feed sample was precise-fed (60 g) to geese and excreta were collected for 48 h. A N-free diet and fasting methods were used to evaluate the endogenous amino acid losses. Endogenous losses of 3 amino acids were significantly different (P < 0.01) with the N-free diet and fasting methods. The TAAA of soybean meal, fish meal, and cottonseed meal determined by N-free diet method ranged from 84.49 to 97.09%, 89.18 to 98.16%, and 77.09 to 98.32%, respectively. The TAAA of these 3 diets determined by the fasting method ranged from 83.50 to 97.77%, 88.08 to 99.60%, and 76.09 to 98.09%, respectively. However, there were only a few small differences (P > 0.05) between methods in each amino acid. In conclusion, there was no difference in determination of the amino acid availability of these feedstuffs using cecectomized ganders between the N-free diet and fasting methods.
Wang
Z Y
ZY
College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu Province, PR China. dkwzy@263.net
Shi
S R
SR
Shi
Y J
YJ
Zhang
J
J
Zhou
Q Y
QY
D000596:Amino Acids / Q000378:metabolism* / Q000493:pharmacokinetics; D000818:Animals; D003369:Cottonseed Oil / Q000378:metabolism; D004044:Dietary Proteins / Q000378:metabolism* / Q000493:pharmacokinetics; D005396:Fish Products; D005766:Gastrointestinal Contents / Q000737:chemistry*; D005777:Geese / Q000378:metabolism*; D008297:Male; D011897:Random Allocation; D030262:Soybean Proteins / Q000378:metabolism / Q000493:pharmacokinetics
D000596:Amino Acids; D003369:Cottonseed Oil; D004044:Dietary Proteins; D030262:Soybean Proteins