Production performance and egg quality characteristics of pullets and spent layers were compared in this study. Forty birds, each from the flocks of pullets (24 weeks old) and spent layers (76 weeks old) were selected as experimental birds. The birds from each age group were divided into five replicates, each comprising of eight birds. All the experimental birds were fed a commercial layer rati...

Two studies were conducted to compare bioefficacy of liquid DL-methionine hydroxy analogue-free acid (MHA-FA) and DL-methionine (DL-Met). Biological efficacy was determined for egg production, feed consumption, egg mass, and egg weight using linear and nonlinear regression models. In Experiment 1, five levels of DL-Met (0.023, 0.045, 0.068, 0.090 and 0.113%) and MHA-FA (0.026, 0.051, 0.077, 0.1...

OBJECTIVE A study was conducted to test six threonine (Thr) levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64%) to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. METHODS Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. RESULTS...

A study was conducted to compare bioefficacy of liquid DL-methionine hydroxy analogue-free acid (MHA-FA) and DL-methionine (DL-Met) in laying hens. Biological efficacy was determined for egg production, egg mass, and egg weight using five regression models. Four levels of DL-Met (0.012, 0.024, 0.036, and 0.048%) and MHA-FA (0.014, 0.027, 0.041, and 0.054%) were added on an equimolar basis to a ...

White Leghorn hens were fed diets containing 0, 300, 600, or 1200 ppm technical grade DDT for three 28-day periods. The 1200 ppm diet caused tremors and 33% mortality in the final period, but no gross toxicity symptoms were seen in birds fed the other diets. Egg production was decreased during the third period by 600 or 1200 ppm. Egg weight was decreased during the third period by 600 or 1200 p...

This experiment was designed to evaluate the effects of different sources of calcium at different rates and cholecalciferol(Vitamin D3) on the performance and egg quality of Hy-line W-36 Laying hens. In this study a total of 648 hens were managed in a completely randomized design using a factorial arrangement of 3 × 3 × 2 treatments, with three calcium sources (oyster shell, OS; ground limeston...