Breed and Seasonal Variations in the Testicular Morphometry, Gonadal and Extragonadal Sperm Reserves of the Barred Plymouth Rock and Nigerian Indigenous Breeds of the Domestic Fowl

Abstract

Breed and seasonal influence on testicular morphometry, Gonadal Sperm Reserves (GSR), Extragonadal Sperm Reserves (ESR) was investigated in the barred Plymouth rock and the Nigerian indigenous breeds of the domestic fowl. Twenty sexually matured birds per breed were studied in the four seasons of the year. Breed significantly (p<0.01) influenced the body weight (2.11 +/- 0.05 vs. 1.58 +/- 0.02), paired testes weight (21.92 +/- 1.46 vs. 12.43 +/- 0.91) and all other morphometric parameters with the barred Plymouth Rock showing superiority over the Nigerian indigenous breed. The GSR, ESR and their efficiencies (GSR/g, ESR/g) were highly and significantly (p<0.01) higher in the barred Plymouth rock. Season neither significantly (P>0.05) influenced the testicular morphometric parameters, GSR, ESR nor gonadal sperm reserve/gram testis (GSR/g). The higher numerical differences observed in morphometric parameters, GSR and ESR during the early and late dry seasons suggested that the dry season favors sperm production, hence sperm reserve potentials. The testicular weight was significantly (p<0.001) correlated not only to the body weight (r = 0.63) but to paired Tunica albuginea (= 0.98, p<0.001) and paired epididymal weight (r = 0.69, p<0.001). There was also a significant (p<0.001) and positive correlation between the testicular weight and GSR (r = 0.84, p<0.001). The GSR/g (r = 0.77; p<0.001) ESR (r = 0.86; p<0.001) and ESR/g (r = 0.50, p<0.001). Based on these observations it is concluded that genetic improvement of the Nigerian indigenous breed of the domestic fowl can be carried out by increasing their body weight, hence, testicular weight through crossbreeding with the heavier barred Plymouth rock to achieve improved sperm production and reserve for year round artificial insemination.

Effect of human menopausal gonadotropin on testicular morphometry, gonadal and extragonadal sperm reserves of rabbit bucks

“…This deduction is supported by Adeyemo et al (2007) and Gbore and Egbunike (2008), who observed high correlations between testis weight, body weight, sperm production and testis sperm reserve potential. In line with this, Orlu and Egbunike (2010) also propounded that because testis weight is highly significantly (P<0.01) related to gonadal and extragonadal sperm reserves, daily sperm production, gonadal and extragonadal sperm reserves could be calculated from testicular weight. On the contrary, Orgebin-Crist (1968), Weisgold and Almquist (1979), and Wildeus and Entwistle (1982) reported no correlation between gonadal sperm reserves and body weight in rabbits.…”

Reproductive Parameters of the West African Dwarf Bucks Raised in the Guinea Savannah Zone of Nigeria

“…al., 2005). The growth and development of testicular organs in various species of farm animals has been well documented (Orlu and Egbunike, 2010;Osinowo et. al., 1981;Bitto and Egbunike, 2010).…”

Biometric Study of the Reproductive Organs of Three Breeds of Sheep in Nigeria

“…However, the growth and development of testicular organs in various species of farm animals has been well documented (Osinowo et al, 1981;Rekwot et al, 1987;Etches, 1996;Oyeyemi & Ubiogoro, 2005;Bitto & Egbunike, 2006;Togun & Egbunike, 2006;Obidi et al, 2008;Ugwu, 2009;Orlu & Egbunike, 2010). Osinowo et al (1981) and Togun & Egbunike reported that testes size is a good indicator of the present and future sperm production in animals.…”