Genetic selection procedures applied to improve broiler performance may negatively impact the subsequent reproductive efficiency of breeders, particularly in males. Identification of traits that reliably indicate individual male fertility would facilitate selection for reproduction. We hypothesized that physical traits, such as comb area, relative testicular weight, and testicular weight asymme...

a 3×3 factorial arrangements experiment was conducted to evaluate the effect of fennel extract and vitamin d3 on performance, hatchability, chick quality characteristics and immunity. this experiment was done with using 360 ross 308 broiler breeders after molting (84 - 92 weeks) in a completely randomized design with three levels (0, 50, and 100 mg/kg of diet) of fennel extract and three levels...

an investigation was carried out to evaluate the growth performance of six commercial broiler hybridsavailable in iran (arbor acres, arian, cobb 500, hubbard, lohmann and ross 508). two hundred and fiftyfertile eggs of each hybrid were taken from different breeder farms, all over the country. the similarity offlocks ages and their health conditions were considered. after hatching, the sexed chi...

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...

in this research, buffalo production was studied from view points of housing, feeding, milk production and reproducrion in rural area of shoushtar, khuzestan. the results of this study revealed that in a herd 66.7 , 8.3 and 25 % were breeders (adult females), adult bulls and valves. each breeder female buffalo had 3-17 parturation in whole life. first service was done at 18 month after birth an...

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...