Effects of tryptophan and probiotic supplementation on growth and behavior in quail.

In laying hens, a diet supplemented with tryptophan (Trp) has been shown to affect their pecking behavior. However, unlike this positive effect, Trp is also involved in negative effects on behavior and stress through indolic pathways. Indole production can be reduced by probiotics (Pro), thus we hypothesized that Pro may prevent negative effects of Trp and increase beneficial effects on behavior in birds.

Dietary methionine deficiency reduces laying performances of female common ducks and impacts traits of interest of their mule ducklings.

The effects of maternal nutrition on offspring phenotypes have been mainly documented over the past years in mammals, and are now studied in poultry as well. In the present study, we investigated the effects of a reduced level of dietary Methionine (Met) on laying performances of common laying ducks and their impacts on the phenotype of their mule ducklings. A total of 60 female laying ducks were divided into 2 dietary treatments at 10 wk of age.

Food restriction but not fish oil increases fertility in hens: role of RARRES2?

Overfed hens selected for their rapid growth become fatter and develop reproductive disorders. Herein, we aimed to demonstrate that food restriction leading to a weight reduction and/or a supplementation with fish oil may be effective in preventing reproductive disorders through the regulation of adipokine expression in broiler hens. This study included four groups of food restricted (Rt) or hens (Ad, feeding at a rate 1.

Effect of different levels of feed restriction and fish oil fatty acid supplementation on fat deposition by using different techniques, plasma levels and mRNA expression of several adipokines in broiler breeder hens.

Background: Reproductive hens are subjected to a restricted diet to limit the decline in fertility associated with change in body mass. However, endocrine and tissue responses to diet restriction need to be documented.

Objective: We evaluated the effect of different levels of feed restriction, with or without fish oil supplementation, on metabolic parameters and adipokine levels in plasma and metabolic tissues of reproductive hens.

Short-term nutritional strategies before slaughter are effective in modulating the final pH and color of broiler breast meat.

The poultry meat industry is faced with various quality issues related to variations in the ultimate pH of breast meat. The aim of this study was to evaluate the possibility to control breast ultimate pH by distributing finishing diets varying in amino acid (AA) and energy content for a short period before slaughter. Experimental diets were distributed to PM3 broilers on the last 3 d before slaughter (36 d of age).

2-Hydroxy-4-methylselenobutanoic acid induces additional tissue selenium enrichment in broiler chickens compared with other selenium sources.

Two experiments were conducted in broiler chickens to compare the effect of different Se sources on Se tissue enrichment: sodium selenite (SS), seleno-yeast (SY), and a new organic Se source (SO) containing 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) as an active substance. For each experiment, treatments differed only in source or dose of Se additive. Relative efficiency was compared by plasma and tissue [muscle (pectoralis major) and liver] total Se concentrations.

Moderate heat challenge increased yolk steroid hormones and shaped offspring growth and behavior in chickens.

Background: Environmental challenges might affect the maternal organism and indirectly affect the later ontogeny of the progeny. We investigated the cross-generation impact of a moderate heat challenge in chickens. We hypothesized that a warm temperature--within the thermotolerance range--would affect the hormonal environment provided to embryos by mothers, and in turn, affect the morphology and behavioral phenotype of offspring.

Effect of 2-hydroxy-4-methylselenobutanoic acid as a dietary selenium supplement to improve the selenium concentration of table eggs.

The aim of this study was to compare the effects of a new organic Se [2-hydroxy-4-methylselenobutanoic acid (HMSeBA)] with routinely used mineral and organic Se sources (sodium selenite and selenized yeast) on chosen performance criteria and Se deposition in egg and muscle of laying hens. A total of 240 laying hens (40 wk of age) were randomly assigned to 6 treatments for 56 d with 8 replicates of 5 hens per replicate. The 6 treatments were as follows: control group received basal diet without Se supplementation; the second, fourth, and sixth experimental groups (SS-0.

Influence of increasing slaughter age of chickens on meat quality, welfare, and technical and economic results.

Because of the increasing demand for raw cuts and processed products, there is a trend to producing very heavy broilers. Breeds that are used for such kinds of production have been intensively selected for growth rate and breast meat yield, and birds are reared for a longer period than standard broilers. This study was to evaluate the effects of increasing slaughter age on technical and economic factors, including production efficiency and environmental costs, bird welfare, and breast meat quality in a modern heavy broiler line.