Testicular morphometry and sperm reserves of local turkey toms fed varying levels of protein in the diet

Abstract

The morphometry and sperm reserves of the testis, epididymis and vas deferens of three groups (n=5/ group) of sexually active adult local turkey toms fed isocaloric diet with varying levels (12 %, 16 %, 20 %) of protein were studied for sixteen weeks. The weights of the toms before treatment were between 3.5 – 4.5 kg, while at the end of the experiment the mean ± SD live weight were 5.29 ± 0.65, 5.39 ± 0.45 and 5.63 ± 0.49 kg for groups 1, 2 and 3 respectively. The mean ± SD weights of the paired tunics, testis, epididymis and vas deferens, respectively, were 0.41 ± 0.11 g, 8.27 ± 2.37 g, 0.28 ± 0. 07 g and 0.36 ± 0.11 g (group 1): 0.43 ± 0.02 g, 8.50 ± 0.65 g, 0.33 ± 0.11 g and 0.40 ± 0.11 g (group 2) and: 0.49 ± 0.16 g, 9.83 ± 3.08 g, 0.40 ± 0.13 g and 0.50 ± 0.18 g, (group 3). The mean ± SD lengths of the testes were: 3.72 ± 0.34 cm, 4.40 ± 0.47 cm and 4.48 ± 1.14 cm; the epididymis: 3.12 ± 0.56 cm, 3.17 ± 0.67cm and 3.48 ± 0.49 cm, and the vas deferens: 17.27 ± 1.10 cm, 17.33 ± 0.93 cm and 17.49 ± 1.10 cm, for groups 1, 2 and 3, respectively. Mostly, the parameters of the left organs were greater than those of the right. The mean ± SD weight of the testes positively correlated with that of the epididymis in all the groups (r = 0.72, 0.65 and 0.87 for groups 1, 2 and 3 respectively) and the vas deferens (r = 0.54, 0.72 and 0.75 for groups 1, 2 and 3 respectively). The gonadal sperm reserves were 0.19 ± 0.00 x 10⁹ cells/ml, 0.21 ± 0.00 x 10⁹ cells/ml and 0.21 ± 0.00 x 10⁹ cells/ml for groups 1, 2 and 3 respectively. The mean ± SD extragonadal sperm reserves were, epididymis: 0.08 ± 0.00 x 10⁹ cells/ml, 0.12 ± 0.01 x 10⁹ cells/ml, 0.18 ± 0.00 x 10⁹ cells/ml, and vas deferens: 2.00 ± 0.13 x 10⁹ cells/ml, 2.82 ± 0.50 x 10⁹ cells/ml and 3.75 ± 0.60 x 10⁹ cells/ml for the three groups respectively. The vas deferens had about 88 %, of the extragonadal sperm reserve in group 1 and 90 % in groups 2 and 3. Sperm reserve was positively correlated to body weight and to the length of the testis. The results suggest, therefore, that morphometry and sperm reserves were better in turkey toms fed 16 % and 20 % than 12 % protein diets.

Keywords: Crude protein, Fertility, Morphometry, Reproduction, Sperm reserves, Turkey tom