Effects of season on the reproductive organs and steroid hormone profiles in guinea hens (Numida meleagris)

Abstract

The study documented gross anatomical and histological differences in the reproductive organs of 28 breeding and non-breeding female guinea fowls. Peripheral progesterone and 17β-oestradiol concentrations were also compared in breeding and non-breeding hens. In non-breeding females, all ovarian and oviducal gross anatomical features had significantly regressed. Histologically, some of the changes in a regressing oviduct include systematic changes in height and size of all epithelial cells in all regions of the duct, absence/sparse ciliation of portions of surface epithelium in the magnum, isthmian and uterine regions, general loss of cytoplasmic mass, reduction in size and degeneration of tubular glands. Mucosal folds in all regions of the oviduct except the infundibular lip were higher in breeding females. No difference was found between the two groups in plasma progesterone concentrations. Breeding females, however, had higher peripheral oestradiol concentrations than non-breeding females. About 2 h prior to oviposition, plasma oestradiol concentrations peaked at 2.4-fold (230 pg/ml) compared with baseline concentration and plasma progesterone concentrations by nearly 9-fold (5.29 ng/ml) of baseline. Significant regression and changes in the histological structure of the ovary and oviduct had occurred in non-breeding females, and lower peripheral oestrogen concentrations may be responsible for this phenomenon.

Age-related changes in the gross anatomy of the reproductive organs, and associated steroid hormone profiles in male and female guinea fowls (Numida meleagris)

“…For instance, while Furr (1969) reported higher values in laying birds about 12–14 h after ovulation, Etches (1990) noted that the peak occurs 6 to 4 h before ovulation. Abdul-Rahman et al. (2016a) also reported a concentration of 5.29 ng/ml about 1–2 h prior to lay and 0.57 ng/ml post-lay in the guinea fowl.…”

“…As with testosterone, 17β-oestradiol assay had also been previously validated for guinea fowl ( Abdul-Rahman et al., 2016a ). Using the Oestradiol Maia kit (RADIM diagnostics, USA), all samples were evaluated in one assay, and intraassay CV was 9.8%.…”

“…A right ovary is present as a rudiment at hatching, but this decreases in size and persists throughout life only as an inconspicuous vestige ( Hodges, 1974 ). In the guinea fowl, Awotwi (1975) reported a steady increase in ovarian weight from 0.04 g at 4 WOA to 30.5 g at sexual maturity (36 WOA); this regressed to 2.7 g in non-breeding-hens ( Abdul-Rahman, Obese, Robinson, Awumbila, & Jeffcoate, 2016a ). The reports of Romanoff and Romanoff (1949) indicated that at day old, the ovary of a chick weighed 0.03 g. This increased to 0.32 g, 2.66 g, 6.55 g and 38.0 g at 3, 4, 5 months and after pullet had laid the first egg, respectively.…”

Guinea fowl (Numida meliagris) value chain: Preferences and constraints of consumers

“…Where demand is not met as occurs during the rainy season, the wholesalers travel far, assembling birds from the few farmers willing to sell to meet the demand of their clients [29]. The seasonal availability of products may be related to the seasonal breeding habit of these birds [30][31], as farmers are usually unwilling to sell their birds during the breeding season, which occurs in the rainy season. X2 (5%) = 44.7, df = 2, p = 0.064…”

Photoperiod induced the pituitary differential regulation of lncRNAs and mRNAs related to reproduction in sheep

“…ADCYAP1R1 was the receptor gene of pituitary adenylate cyclase-activating polypeptide type 1 receptor ( PAC1 ), Mercer et al found that SNP rs2267735 within the ADCYAP1R1 located within a predicted estrogen response element, which regulates gene transcription when bound to estradiol (E 2 ) activated estrogen receptor alpha (ER α ) ( Mercer et al, 2016 ). However, numerous pieces of evidence have confirmed that the concentration of E 2 was strongly affected by seasonal or photoperiodic change ( Lai et al, 2012 ; Abdul-Rahman et al, 2016 ; Carr et al, 2003 ). PER1 is one of the typical clock genes, whose expression is significantly correlated with circadian rhythm ( Albrecht & Eichele, 2003 ; Messager et al, 2001 ).…”