Estimation of bioavailability of DL-methionine hydroxy analogue relative to DL-methionine in layers with exponential and slope-ratio models.
An experiment was conducted using molted hens to estimate the bioavailability of DL-methionine hydroxy analogue-free acid (MHA-FA) relative to DL-methionine (DLM). In this experiment, 5 supplemental levels (0.012, 0.024, 0.036, 0.048, and 0.060%) of DLM or equimolar concentrations of MHA-FA were added to a basal diet containing 14.97% protein and 0.27% methionine. The low protein diet was used to increase the sensitivity of laying hens to methionine deficiency. Feed consumption, egg production, egg mass, and egg weight increased (P < 0.05), and feed conversion decreased (P < 0.05) when DLM or MHA-FA was added to the basal diet for some supplemental methionine levels. There was no difference (P > 0.05) in feed consumption between hens fed DLM and hens fed MHA-FA. Regression analysis showed that the bioavailability of MHA-FA relative to DLM on a molar basis was 88.7% (egg production), 88.0% (egg mass), and 84.6% (egg weight) with the exponential model, and was 89.7% (egg production), 89.6% (egg mass), and 86.8% (egg weight) with the slope-ratio model. The average bioavailability of MHA-FA relative to DLM was 88% on a molar basis.
Liu
Z
Z
Department of Poultry Science, Auburn University, Auburn, Alabama 36849 USA.
Bateman
A
A
Bryant
M
M
Abebe
A
A
Roland
D
D
D000821:Animal Feed; D000818:Animals; D001682:Biological Availability; D002645:Chickens / Q000378:metabolism*; D019587:Dietary Supplements; D004435:Eating / Q000502:physiology; D004531:Eggs; D005260:Female; D005544:Forecasting; D008715:Methionine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D008962:Models, Theoretical; D010058:Oviposition / Q000502:physiology; D012044:Regression Analysis
C008391:alpha-hydroxy-gamma-methylmercaptobutyric acid; D008715:Methionine