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...

Badgers were sampled once during the sexually inactive season (July-November) and during the breeding season (February-April) and testosterone and dihydrotestosterone (DHT) concentrations were measured by radioimmunoassay after separation by chromatography. Concentrations of both hormones were higher in the breeding than non-breeding season, but the mean ratio of testosterone to DHT was greater...

Yearly, testosterone (T) levels fluctuate as many vertebrates cycle through reproductive and non-reproductive periods. Among many temperate birds, it is well established that levels of T peak as gonads recrudesce for breeding and then fall as gonads regress prior to the non-breeding season. While the tissues producing breeding season T are well studied, the tissues responsible for non-breeding ...

July September 2017 1326 JCPS Volume 10 Issue 3 Haematological and Biochemical Alterations in Sub Clinically Affected Dromedary Camels with Trypanosoma evansi During Breeding Season in Egypt Faten A.M Abo-Aziza*, Heba M. Ashry and Somia A. Nassar Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Center, Giza, Egypt.
 *Corresponding author: E-Mail: f...

Testosterone (T) and its metabolites are important in the regulation of reproductive behavior in males of a variety of vertebrate species. Aromatase converts T to estradiol and 5alpha-reductase converts T to 5alpha-dihydrotestosterone (DHT). Male green anole reproduction depends on androgens, yet 5alpha-reductase in the brain is not sexually dimorphic and does not vary with season. In contrast,...

Effects of Body Condition Recent University of Arkansas research determined the interactive effects of forage environment and body condition on the calving rate of beef cows. multiparous beef cows (1/4 to 3/8 Brahman) were managed to achieve marginal (4.7) or good (6.6) body condition scores (BCS) over approximately 5 months before the initiation of the breeding season. growth, endophyte acres ...

Kisspeptin signaling in the hypothalamus appears critical for the onset of puberty and driving the reproductive axis. In sheep, reproduction is seasonal, being activated by short days and inhibited by long days. During the non-breeding (anestrous) season, gonadotropin-releasing hormone (GnRH) and gonadotropin secretion is reduced, as is the expression of Kiss1 mRNA in the brain. Conversely, the...

The aim of this study was to investigate the seasonal expression of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) mRNA and protein by real-time PCR and immunohistochemistry in the wild ground squirrel (WGS) testes. Histologically, all types of spermatogenic cells including mature spermatozoa were identified in the breeding season (Apri...

In anurans, circulating levels of androgens influence certain secondary sexual characteristics that are expressed only during the breeding season. We studied the contractile properties of external oblique muscles (used to power sound production) in a species of North American gray tree frog, Hyla chrysoscelis, during the breeding season and also in testosterone-treated captive males and females...

The aim of this study was to elucidate the regulatory role of androgen in the follicular development of wild female ground squirrels. Immunohistochemical staining of FSHR, LHR, P450c17, P450arom, androgen receptor (AR), estrogen receptors (ERa and ERb) were executed in ovaries of female ground squirrels from both breeding and nonbreeding seasons. In addition, total ovarian proteins were extract...