| Abstrakt: |
This study was conducted to investigate the effect of season on histomorphological changes in the testes of two colour types of helmeted guinea fowls. Testes were collected from 192 helmeted guinea cocks (96 each of Pearl and Black strains) from four local poultry abattoirs in Bauchi metropolis, Bauchi State, Nigeria during the rainy (May to September) and dry (October to December) seasons. Records were collected on live weight, paired testes weight, right and left testes weights, volumes, lengths, widths, diameters and gonadal sperm reserves (GSR) and subjected to analysis of variance and simple correlation coefficients. Live weight was similar for the two strains Pearl and Black (1.24 and 1.22 kg). Season and month had significant (P<0.001) effect on all testicular morphometric parameters measured. No significant difference was observed in testicular morphometry between the strains. Correlation among live weight, testicular morphometry, and gonadal sperm reserve were moderate to high, positive and significant (P<0.01). The relationship between gonadal sperm reserve and body weight was low (r = 0.13) but significant (p<0.01) while testicular weight was highly (p<0.01) correlated (r = 0.82) with gonadal sperm reserve. Histologically, it was shown that season had effect on seminiferous tubules diameter and inter tubular tissues indicating lower, larger, medium and regressed diameters for early rainy, mid rainy, late rainy and early dry seasons respectively. The seminiferous tubules show cells in active spermatogenesis with numerous spermatids during mid-rainy season while regressed follicles filled with connective tissues along some blood vessels were observed in dry season. Variations in season and month changed the histomorphology of the testes as well as gonadal sperm reserves. [ABSTRACT FROM AUTHOR] |
