Toward standardized amino acid matrices for exogenous phytase and protease in corn–soybean meal–based diets for broilers

Abstract

A total of 468 male Ross 308 broilers were used in a digestibility study to determine the additivity of apparent or standardized amino acid ( AA ) digestibility values for corn, soybean meal ( SBM ), or a mixture of corn and SBM that were supplemented, or not, with either phytase, protease, or a combination of phytase and protease. These treatments generated a total of 12 experimental diets that were arranged in a 3 × 4 design. A nitrogen-free diet was also fed to estimate endogenous AA loss. Apparent and standardized AA digestibility values were assessed on day 28 posthatch. The apparent digestibility of AA in the complete diet was higher ( P < 0.05) than expected based on the digestibility of the corn and SBM individually. However, this overestimation was corrected by the adjustment to standardized values. Importantly, addition of protease or the combination of protease and phytase increased ( P < 0.05) the digestibility of AA in corn and SBM. Furthermore, these effects were arithmetically coherent with respect to the measured effects of the enzymes in the mixture of corn and SBM, even improving the additivity of AA digestibility values when assessed on an apparent basis. This study demonstrates that the effect of exogenous protease and phytase on AA digestibility in complete diets is predictable based on measurements made in individual ingredients. In addition to improving digestibility values per se , exogenous protease and phytase may enhance precision in least cost formulation systems.

Progress in ileal endogenous amino acid flow research in poultry

“… a References: Siriwan et al [ 31 ]; Adedokun et al [ 32 ]; Ravindran et al [ 57 ]; Adedokun et al [ 72 ]; Adedokun et al [ 73 ]; Adedokun et al [ 74 ]; Ravindran et al [ 80 ]; Adedokun et al [ 81 ]; Adedokun et al [ 82 ]; Adedokun et al [ 83 ]; Golian et al [ 84 ]; Ravindran et al [ 85 ]; Woyengo et al [ 86 ]; Soleimani et al [ 87 ]; Kong and Adeola [ 88 ]; Ravindran et al [ 89 ]; Toghyani et al [ 90 ]; Cowieson et al [ 91 ]; Osho et al [ 92 ]; An et al [ 93 ]; Cowieson et al [ 94 ] b Average values and variability were calculated after removal of the following extreme outliers: Adedokun et al [ 32 ]; Adedokun et al [ 73 ]; Kong and Adeola [ 88 ] …”

Standardized ileal amino acid digestibility of protein sources for broiler chickens is influenced by the feed form

“…The standardized ileal digestibility ( SID ) involves a correction for the inevitable basal endogenous AA ( EAA ) losses from the gastrointestinal tract ( Lemme et al., 2004 ). It has been documented that the SID AA values are more additive than the apparent ileal digestibility ( AID ) values in terms of accuracy of feed formulation ( Kong and Adeola, 2013 ; Cowieson et al., 2019 , 2020 ).…”