Avian influenza is an important disease of poultry with the potential to cause major epidemics resulting in significant economic losses. The presence of avian influenza viruses (AIV) in chickens in Iran has not been previously reported. An avian influenza outbreak in broiler, layer and breeder farms occurred during a very hot summer in July 1998. Three AIV isolates designated as 101, 102 and 10...

A study was conducted comparing ovary and oviduct development following photostimulation in two lines of turkey breeder stocks (female line and male line). Birds were euthanatized for assessment of reproductive organ morphology at 3-d intervals following photostimulation (203 d of age) to 245 d and on the day following their first oviposition. The age at first oviposition was similar for both l...

Age-associated lesions were characterized in two outbred stocks of barrier-reared male Sprague-Dawley rats. Seventy-two virgin Hap:(SD) between 6-29 months of age and 113 retired breeder Crl:COBS[R]CD[R]CDR(SD) between 12-38 months of age were evaluated for the presence of lesions in all major organ systems. Rats of both stocks developed a spectrum of neoplastic, inflammatory and degenerative d...

Here, we review recent empirical advances that have improved our understanding of why and when sex change occurs. We show that sex-changing animals use a greater diversity of strategies to increase their reproductive success than was previously recognized: some individuals change sex early, others change sex late, some individuals change sex more than once, and others do not change sex at all. ...

spondylitis is a reemerging epidemic spinal infection in male broiler chickens (5 to 7 weeks of age) as well as broiler breeder roosters (15 to 18 weeks of age). among various causative agents, enterococcus species and in particular e. cecorum, a gram-positive bacterium as a gastrointestinal flora of birds, have mostly been isolated. on late september 2015, a number of 10 weeks old roosters wit...

Among cooperatively breeding species, helpers are hypothesised to increase the survival of breeders by reducingbreederworkload inoffspring care and increasedgroupvigilance against predators. Furthermore, parental nepotism or other benefits of group living may provide a survival benefit to young that delay dispersal to help. We tested these hypotheses in the Karoo Scrub-robin (Cercotrichas coryp...

In capital breeders, individual differences in body size and condition can impact mating effort and success. In addition to the collateral advantages of large body size in competition, large nutrient reserves may offer advantages in endurance rivalry and enable the high rates of energy expenditure associated with mating success. We examined the impacts of body reserves and dominance rank on ene...

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...