Gossypol, a natural component of cottonseed meal, exists in positive (+) or negative (-) enantiomeric forms, and their levels and ratio could be altered by developing new genetic strains of cotton. Two experiments were conducted to determine the relative toxicity of the individual gossypol enantiomers in laying and broiler breeder hens. In the first experiment, 25 individually caged Hy-Line W-3...

Effects of low-density broiler breeder diets on offspring performance and mortality were studied using 2,100 female and 210 male Cobb 500 breeders. Breeder treatments involved 4 experimental groups and a control group with normal density diets (ND, 2,600 kcal of AME/kg during rearing and 2,800 kcal of AME/kg during laying). In treatment 2, nutrient densities were decreased by 12% (LD12) and 11%...

Both environmental and genetic factors can dramatically affect reproductive performance in mice. In this study we have focused on the identification of genetic regions, quantitative trait loci (QTL), which affect the breeding capacity of female mice. We have identified polymorphic microsatellite markers for the mouse strains used and performed a genomewide scan on 237 females from a gene-segreg...

The effects of broiler breeder age (26, 28, and 30 wk) and incubator relative humidity (43, 53, and 63% RH) on yolk sac weight and composition in broiler hatching eggs between 16 and 19 d of incubation were evaluated. Percentage yolk sac weight was reduced in eggs from the youngest (26 wk) breeder hens and in eggs incubated at 53% RH. Percentage yolk moisture, in eggs from the youngest hens, wa...

avian reoviruses (arvs) are considered as an important cause of several diseases in poultry, particularlyarthritis and tenosynovitis. tenosynovitis and arthritis, which are among the causes of chronic lameness inbreeder flocks, can result in reduced egg production and culling of breeder hens. in this study, the molecularcharacteristics of arvs in some broiler breeder flocks were investigated in...

We examined the proximate causes of delayed breeding and alloparental behavior in the cooperatively breeding red-cockaded woodpecker by measuring plasma concentrations of testosterone (T) and prolactin (PRL) in female breeders, male breeders, and male helpers during different stages of the reproductive cycle. Male breeders and helpers have low T during the prebreeding period, highest T during c...

The modern broiler and breeder are performing at levels never seen before. In order to multiply by 15x (or more) their bodyweight in just four weeks, they do not have the time to correct the effects of nutritional deficiencies. In a recently published paper coming from the University of Alberta, the effect of genetic selection was studied using unselected strains from 1957, 1978 and a 2005 comm...

Astragalus Polysaccharide (APS) is an important feed additive due to its immunomodulatory functions. Previous studies have proven that miRNAs play important roles in posttranscriptional gene regulation. Our goals were to identify differentially expressed miRNAs in testes in responses to APS dietary supplements and to find the effects of APS on breeder cock testes. We measured several enzymatic ...

Metabolic, immune, and physical status of chicks can impact the incidence of morbidity and mortality of broilers during the first week of production. Assessments of chick quality are made primarily by subjective observations with few quantitative measurements. Given a better understanding of how broiler breeder hen age and nutrient intake may influence progeny physiology, certain actions can be...