Testis development and gonadotropin secretion in broiler breeder males

Abstract

One-day-old chicks were used to evaluate testis development and concentrations of luteinizing hormone, follicle-stimulating hormone (FSH), and testosterone during ontogenesis. Males on a conventional breeder program (control) were reared on a 15L:9D photoperiod and ad libitum food and water intake for 2 wk. On the third week, males were placed on a restricted diet and the photoperiod was reduced to 8L:16D. Males on a pedigree breeder program (broilerized) were reared on a 23L:1D photoperiod and unrestricted food and water intake for 6 wk. At 7 wk, males were placed on a restricted diet and the photoperiod was reduced to 8L:16D. On wk 18, both treatment groups were photostimulated (16L:8D) until the end of the experiment (50 wk). After photostimulation, there was an exponential increase in testis weight (TW), FSH, and testosterone concentrations. At 28 wk, TW from broilerized males were significantly heavier than those from control birds, and concentrations of luteinizing hormone, FSH, and testosterone were maximal at that time. After 28 wk, there was a significant decrease in FSH and testosterone concentrations that were associated with reduced TW. No correlation was observed between BW and TW. However, TW was highly correlated with FSH concentrations and daily sperm production. Our data suggest that management and photoperiod had a profound effect on testicular function that was associated with FSH concentrations in male broiler breeders.

Secondary sexual traits and semen characteristic of chicken germline chimeras

“…Contrary to the investigations of McGary, Estevez, and Russek‐Cohen (), who found the positive correlation between comb area and testes weight, and Møller and Erritzoe (), who stated positive relationship between badge size and testes size in house sparrow, our results did not show any relationship between head ornaments measurements and testes size. We also did not find any correlation between body weight and testes weight, which stays in contrary to the results of Pitcher, Dunn, and Whittingham () and Møller and Pomiankowski (), but supports the ones of Vizcarra, Kirby, and Kreider () and Denk and Kempenaers ().…”

Comb, cloaca and feet scores and testis morphometry in male broiler breeders at two different ages

“…It is also observed that heavy roosters were also those who had higher testes weights (Table 1). Vizcarra et al (2010) found a strong correlation between testes weight and FSH, hormone associated with the proliferation of Sertoli cells, important in the development of spermatogenesis. It is speculated that heavy roosters have a higher concentration of circulating gonadotropins, which directly influences the proliferation of spermatogenic germ cell line, leading to increased epithelial height.…”

“…The genetic selection on broiler breeder lineages (Gallus gallus domesticus) has been focused on the production of broiler chickens capable of achieving better slaughter weight ratios, carcass yield, and increased breast and thigh, with reduced feed conversion rate (Vizcarra et al 2010). However, this success seen in the production is contrasted with a sharp drop in fertility after 45 weeks of age, usually related to males (Fragoso et al, 2013).…”

Expression of nerve growth factor and its receptor, tyrosine kinase receptor A, in rooster testes

“…Our results showed that a certain concentration of exogenous FSH increased TrkA mRNA levels in rooster testes, but no changes in NGF mRNA levels were observed. In rooster testes, follicle-stimulating hormone receptor (FSHR) is specifically expressed in Sertoli cells and FSH binds to FSHR in the membranes of Sertoli cells, and then stimulates spermatogenesis (Vizcarra et al, 2010). Therefore, the identification of additional down-stream targets of NGF/TrkA in Sertoli cells and germ cells, as well as factors that interact with NGF directly or indirectly, will help elucidate pathways regulating spermatogenesis in testes (Fig.…”