Reproductive hormones, hepatic deiodinase messenger ribonucleic acid, and vasoactive intestinal polypeptide-immunoreactive cells in hypothalamus in the heat stress-induced or chemically induced hypothyroid laying hen.

Heat stress (HS) effects on reproductive and thyroid hormones have been well documented; however, mechanisms of action are not well understood. Two studies were conducted to determine whether HS-induced and hypothyroid-induced effects are similar in the laying hen, with regard to reproductive hormones and vasoactive intestinal polypeptide (VIP)-immunoreactive cells in the hypothalamus. In study 1, thirty 32-wk-old Hy-Line W-36 laying hens, housed at 22 degrees C, were cannulated.

A small variation in diet influences the Lactobacillus strain composition in the crop of broiler chickens.

Feed composition has the potential to influence the activities of bacteria that colonize the digestive tract of broiler chickens with important consequences for animal health, well being, and food safety. In this study, the gut microbiota of two groups of broiler chickens raised in immediate vicinity but fed either a standard corn/soybean meal ration (corn-soy, CS) or a ration high in wheat middlings (high wheat, HW) was characterized. The findings revealed that this small variation in feed composition did not influence the distribution of microbial species present in the microbial community throughout the digestive tract.

The in vivo digestive fate of the Cry3Bb1 protein in laying hens fed diets containing MON 863 corn.

Two trials were conducted to assess the fate of the Cry3Bb1 protein from YieldGard rootworm corn (MON 863) when fed to laying hens. In the first trial, 2 diets, 1 formulated with MON 863 and 1 with conventional corn, were fed to laying hens (12 replicate cages with 4 hens/cage per treatment) for 8 wk. Daily feed intake (FI), egg production (EP), and BW were measured.

The effect of dietary protein level and total sulfur amino acid:lysine ratio on egg production parameters and egg yield in Hy-Line W-98 hens.

A 3 x 3 treatment arrangement varying in dietary protein and TSAA:Lys was used to evaluate the effect of low-protein diets fed to Hy-Line W-98 laying hens. Phase I was 20 to 43 wk of age with 18.9, 17.

Effect of bird cage space and dietary metabolizable energy level on production parameters in laying hens.

A study was conducted to assess the effects of varying cage spaces on a commercial laying hen strain fed differing levels of dietary metabolizable energy (ME) for 15 wk. Four cage space allowances (342, 413, 516, and 690 cm2/hen) were combined with 3 levels of dietary ME (2,800, 2,850, and 2,900 kcal of ME/kg) in a 4 x 3 factorial arrangement. Each treatment was assigned to 6 replicate cages for a total of 72 cages in randomized complete block design.