Akbar Yaghobfar
Animal Science Research Institute, P.O. Box 31585-1483 Karaj, Islamic Republic of Iran
ABSTRACT
The experiment was performed to study the relationship between apparent and true amino acid digestibility at different levels of feed intake and to compare two procedures, precision feeding and CAM. Rhode Island Red (RIR) adult cockerels were used in the two bioassays, under standard conditions. In the first bioassay (precision feeding) the birds were not fed for 24 h and then various quantities of maize were fed. There were 6 replicates per treatment. Excreta voided during the 48 h of the experimental period were collected; dried and samples were assayed for gross energy, nitrogen and amino acids. In the second bioassay, after a 3-day adaptation period each bird was not fed for 24 h and during the third experimental period maize was fed CAM, in the same rations as those used in the first bioassay. During the 3 days of the experimental period, excreta were collected and frozen for amino acids and chemical analyses. Maize grain was fed at 10 levels (0 to 100 g) to starvation adult cockerels RIR and a group of unfed birds provided metabolic plus endogenous excreta. Birds were fed maize to determine apparent amino acids availability and corrected amino acids availability (true AAA) values. The latter were corrected for the amino acids in maize average 71.93 to 89.30%, respectively. The apparent available amino acids values of the maize, varied between amino acids and between levels of maize input but the true available amino acids values were relatively uniform. The apparent amino acids availability of the maize increase in a curvilinear with maize input. Apparent available amino acids values and dependent on maize intake at lower levels. Finally, the use of available amino acid in practice feed formulation is considered. Because, differences were observed for individual amino acid obtained of maize for birds. The results showed that mean apparent available amino acid values obtained by the precision-feeding procedure, were repeatedly higher than those obtained by CAM. The intercept obtained of regression analysis for precision feeding was higher than that given by CAM method. This may be due to the response of the birds to the methodology applied. It was concluded that procedures of feeding do not influence true available amino acids of maize at different ratio levels.
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How to cite this article
Akbar Yaghobfar, 2005. The Relationship Between Apparent and True Amino Acids Availability in Maize by Comparison of Precision-fed and Conventional Addition Methods. Pakistan Journal of Biological Sciences, 8: 1030-1034.
DOI: 10.3923/pjbs.2005.1030.1034
URL: https://scialert.net/abstract/?doi=pjbs.2005.1030.1034
DOI: 10.3923/pjbs.2005.1030.1034
URL: https://scialert.net/abstract/?doi=pjbs.2005.1030.1034
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