a total of 448 ross 308 male broiler chickens were assigned to seven treatments with four replicates, each containing 16 chicks. the birds were reared from d 21 to 42 and effects of physical sizes (ad libitum by a basal commercial broiler diet with 3050 kcal/kg me and 19.06% cp/kg from 21 to 42 d. the chickens which received clinoptilolite (1.5% with particle size of 0.4-0.8 mm) showed a signif...

the objective of the present study was to detect polymorphism in follicle stimulating hormone receptor (fshr) and beta subunit of follicle stimulating hormone (fshβ) genes and their relation to litter size and body weight trait in baluchi, iran black and arman sheep breeds. pcr-rflp technique using acci and hinfi enzyme treatments employed to detection of polymorphism in fshβ marker site but de...

Natal features (e.g. Julian birth date and birth mass) often have fitness consequences and can be influenced by endogenous responses by the mother to seasonal fluctuations in nutritional quality and photoperiodic cues. We sought to further understand the biological and environmental factors that influence the natal features of a polytocous species in an environment with constant nutritional res...

this study was carried out at sakha animal production research station, during the period from oct., 2009 to sept., 2010. forty rahmani ewes were divided into three treatment groups: the 1st, 2nd and 3rd treatment groups were intramuscularly injected (day 0) with 1 ml gnrh analogue followed by an intramuscular injection with 0.7 ml pgf2α5 (g1), 6 (g2) or 7 (g3) days later. a second dose of 1 ml...

We examined the effects of environmental and genetic factors on the weaning-to-estrus interval (WEI) in sows. In order to perform the analyses of the environmental factors, 8104 observations of the 1st to the 6th WEI were carried out, while 6548 observations of the 1st to the 3rd WEI were carried out for the analyses of genetic factors. The environmental model included as fixed effects, he...

A retrospective study was performed to evaluate the relationships between BW at first insemination and subsequent body development, feed intake, reproductive performance, and culling rate of rabbit does. Young rabbit does are vulnerable to body energy deficit in first lactation, resulting in decreased reproductive performance and high replacement rate. Heavy does at first insemination might be ...

Introduction As an industry, our success in selecting for increased litter size is coming back to haunt us. Data from breeders’ herds in Ontario and reports from elsewhere show that there is a non-linear relationship between litter size and piglet survival, especially peri-natal survival (e.g. Robinson and Quinton, 2002, Lecour. 2000). Data from Robinson and Quinton (2002) reproduced below as F...

Substantial interaction was observed in 3 inbred strains of mice maintained on 5 normal commercial pelleted diets. Strain 0 to.OR was most sensitive to the unknown dietary factor, and the ranking of 0 tO.BR and A2G was reversed across the array of diets, There was no apparent relationship between the 'biological' value of the diet and 21 dietary ingredients determined chemically, The study show...

Predicting the ecological impacts of climate warming is critical for species conservation. Incorporating future warming into population models, however, is challenging because reproduction and survival cannot be measured for yet unobserved environmental conditions. In this study, we use mechanistic energy budget models and data obtainable under current conditions to predict polar bear litter si...