background: this study was conducted to evaluate the effect of melatonin on semen quality and quantity changes and increase of reproductive efficiency in lori-bakhtiari ram in the non-reproductive season. objectives: the purpose of this study was to investigate the effect of melatonin on testicular size and semen qualitative and quantitative changes in the non-breeding season is lori-bakhtiari ...

introduction lori sheep is one of the most important breeds in iran that is mostly bred in lorestan province, north-east of khuzestan and some areas of ilam provinces. the name of this breed is derived from lori tribe, which is one of the major nomadic groups of zagros mountain in western areas of iran. lori sheep is resistant to mountain conditions and hot and dry plains. this sheep breed has ...

The adrenocortical response to acute stress as measured by increase in plasma levels of corticosterone following capture, handling, and restraint over an hour was estimated in free-living male bush warblers at different times of the breeding season on their breeding ground in Chichibu, Honshu, Japan. Initial plasma levels of corticosterone showed a seasonal change, being moderate in April, high...

--Breeding-season pr ductivity (the per capita number of offspring surviving to the end of the breeding season) is seldom estimated for multibrooded songbirds because of cost and logistical constraints. However, this parameter is critical for predictions of population growth rates and comparisons of seasonal productivity across geographic or temporal scales. We constructed a dynamic, stochastic...

Evaluating breeding soundness of bulls is an often neglected management practice. Producers may incorrectly believe that bulls that have previously proven fertile are of sound breeding value for the rest of their lives. They may also assume that new bulls are reproductively sound simply because of some vague or implied guarantee by the seller. Unfortunately, neither assumption is correct. Bulls...

Red deer stags produce an androgen-dependent mane of long hairs only in the breeding season; in the non-breeding season, when circulating androgen levels are low, the neck hair resembles the rest of the coat. This study was designed to determine whether androgen receptors are present in deer follicles throughout the year or only in the mane (neck) follicles when circulating testosterone levels ...

The objective of study was to determine seasonal changes of leptin, triiodothyronine, and thyroxine and to determine whether an effect of thyroid hormones on leptin levels in Arabian mare. Blood samples were collected via jugular venipuncture from 16 Arabian mares during breeding and non-breeding season. Hormone concentrations were measured by radioimmunoassay. Mean concentrations of leptin wer...

To define ovarian follicular kinetics in the equine ovary during anestrus and the breeding season, the follicular population of pony mares was investigated at mid-anestrus and at the beginning and end of the breeding season. There was a clear effect of season on the exit of reserve (primordial and initiated) follicles since at the beginning of the breeding season we noticed a higher mitotic ind...

Animals have to adjust their physiology to seasonal changes, in response to variation in food availability, social tactics and reproduction. I compared basal corticosterone and testosterone levels in free ranging striped mouse from a desert habitat, comparing between the sexes, breeding and philopatric non-breeding individuals, and between the breeding and the non-breeding season. I expected di...