Two experiments were conducted to evaluate the effects of male broiler breeder feed intake on broiler progeny performance. In experiment 1, a low cumulative nutrition program supplied 29,580 kcal of ME and 1,470 g of CP, whereas a high cumulative nutrition program supplied 33,500 kcal of ME and 1,730 g of CP to photostimulation at 21 wk of age. Two diets (HiDiet and LoDiet) were formulated, and...

Repeatedly bred male and female rats of many strains develop hyperglycemia, hyperlipidemia, hypertension, and arteriosclerosis spontaneously. The intensity of their arterial disease and related metabolic derangements appear to be related to their reproductive activity. Repeatedly bred spontaneously hypertensive rats (SHR) were found to have severe hypertension, hyperglycemia, hyperlipidemia, el...

a study was conducted to determine the effects of diet formulation on arian broiler breeder performance in their 50 to 64 wks of age. one hundred and sixty eight female and 24 male breeders were employed in 8 treatments of 3 replicates (7 females plus a male) in a completely randomized design (a factorial experience of 2 × 2 × 2). eight experimental diets were formulated based on three factors,...

Reports on the influence of dietary crude protein on male broiler breeder fertility are not consistent, and therefore an experiment was conducted to determine the effect of three isoenergetic diets containing 10.5%, 12.6% and 15% crude protein, respectively, on Ross broiler breeder male fertility from 26 to 41 weeks of age. Feed allocation was the same for each treatment, and was done according...

Biased operational sex ratios (OSRs) can drive sexual selection on members of the over-represented sex via competition for mates, causing higher variance and skew in reproductive success (RS) among them if an individual's quality is a persistent characteristic. Alternatively, costs of reproduction may degrade breeding performance, creating the opportunity for members of the limiting sex to swit...

Reaching tasks are popular tools for investigating the neural mechanisms of motor skill learning and recovery from brain damage in rodents, but there is considerable unexplained variability across studies using these tasks. We investigated whether breeder, batch effects, experimenter, time of year, weight and other factors contribute to differences in the acquisition and performance of a skille...