Sperm-egg penetration in laying breeder flocks; a technique for the prediction of fertility

The age-related morphological changes of the testes in light ecotype Nigerian indigenous chicken were evaluated in this study using gross anatomical, histological and histomorphometric techniques. The results showed that the testes of 3- to 9-month-old birds were light pink while testes of sexually mature chicken were creamy white in colour. The left and right testicular weight, length, diameter, circumference and the organosomatic indices increased significantly (p .05) between the left and right testes of all the groups. The one-cell layer thick germinal epithelium of the left testes at 3 to 6 months old showed islands of cell proliferation that contained spermatogonia and spermatocytes. At 6 to 9 months, the left testes exhibited numerous early spermatids with occasional occurrence of late stage spermatids while the right testes showed scanty early stage spermatids. At 12 to 18 months, the germinal epithelia of both left and right testes were characterized by the presence of Sertoli cells, spermatogonia, primary spermatocytes, numerous early and late stage spermatids as well as spermatozoa. In conclusion, the morphological features highlighted in the present study show that at pre-pubertal periods, the left testes may develop faster than the right testes. However, both left and right testes may participate actively in the production of spermatozoa during the post-pubertal life.

Assessment of age-related morphological changes in the testes of post-hatch light ecotype Nigerian indigenous chicken.

This study aims to determine the histological and histomorphometric features of the turkey testes based on age levels. Turkey testes were taken from 21 male turkeys which were grouped into 3 different age groups; 12, 20 and 33 weeks. The testes were then processed into histological preparations with a thickness of 3-5 μm and stained with hematoxylineosin (HE). The result showed that histological structure of the turkey testes has different characteristics in different age group. The spermatocytogenesis phase occurred at 12 weeks of age, while the myogenesis phase and the spermiogenesis phase were occurred at 20 weeks and 33 weeks, respectively. Histomorphometric data were analyzed by ANOVA which showed that there was a significant difference between seminiferous tubule diameter, seminiferous tubular epithelial thickness and seminiferous tubule lumen diameter based on age level (P <0.05). As conclusion, there were different spermatogenesis phases with different age group of turkeys. The development of the spermatogenesis phase at each age group of turkey increases the seminiferous tubule diameter, seminiferous tubule epithelial thickness and seminiferous tubule lumen diameter.

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Histology and Histomorphometry of Testes in Turkeys (Meleagris gallopavo) Based on Age Level

Simple Summary Testes are important male reproductive organs that in chickens have been greatly investigated, from pre-hatch to after sexual maturity. The present study investigated the changes in components that occur during growth, and evaluated morphometry of the seminiferous tubules (ST), as well as gonadosomatic index (GSI) in Gallus domesticus at different age stages. The left and right testes were harvested from 70 chickens, then fixed in alcoholic acetate formalin (AAF) fixative solution, and hematoxylin- and eosin-stained tissues were used for microscopic observations. The results revealed that the left testis (LT) and the right testis (RT) exhibited fuzzy ST features, with apoptotic resorption of many tubules observed in both testes of 1-wk-old chicks only. ST formation was completed at 1 month, with an increase of all morphometric parameters in both testes until sexual maturity (3-mo-old): the age at which we recorded the greatest GSI. This study provides details on ST apoptotic resorption, which is a process not yet reported in existing publications, as well as ST morphometry and GSI, from a juvenile stage of growth towards sexual maturity. This can serve as reference material and also as a data update to better understand the morpho-histological changes that occur in chicken testes during growth. Abstract Unlike in many mammals, poultry testes are found in the abdominal cavity where they develop and perform spermatogenesis at high body temperature. Scarce reports among current publications detail the growth of testes and ST morphometry among juvenile chicks. Therefore, this study aims to investigate changes in components occurring in Gallus domesticus testes, by assessing the GSI and morphologically and histologically evaluating the testes and ST morphometry from 1-wk- to 4-mo-old. Right and left testes were collected from 70 healthy chickens divided into seven age-related groups (n = 10) and then immersed into the alcoholic acetate formalin (AAF) fixative solution. Hematoxylin- and eosin-stained tissues were used for microscopic observations. The findings revealed that both testes exhibited smooth features from 1-wk-old to 1-mo-old, and thereafter showed a consistent increase in vascularization until 4-mo-old. Histologically, both testes exhibited unclear ST, with ST apoptotic resorption observed in the 1-wk-old chicks. Until 1-mo-old, ST formed and few spermatogonia differentiated into primary spermatocytes, with all spermatogenic cells observed at 3-mo-old, i.e., sexual maturity. These findings suggest that both testes develop in analogy, and their sizes including increases in length and diameter are related to the spermatogenic activity in the ST. Subsequently, ST resorption by apoptosis is assumed to participate in the physiological mechanism regulating germ cells (GC). Finally, the GSI tended to increase with growth.

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Morpho-Histology and Morphometry of Chicken Testes and Seminiferous Tubules among Yellow-Feathered Broilers of Different Ages

The Nigerian local turkey has the potential to augment the supply of poultry protein in the country and across the region. However, the fecundity of the breed is low due to neglect and lack of improvement. This work is therefore aimed at shedding some light in some reproductive indices of the local turkey under optimum nutrition. A group of fifteen toms and nine hens were used in this study. The males were grouped into three groups of five and placed on varying levels of protein, 12% CP, 16% CP and 20% CP for groups 1, 2 and 3 respectively. Semen samples were collected and analysed twice weekly for thirteen weeks. Ejaculate volume, semen concentration, semen PH, gross and individual motilities, live and dead sperm and sperm morphology were investigated and recorded. Data were summarized as mean ± SEM (Standard Error of the Mean). The toms in groups 3 had significantly (P < 0.05) higher ejaculate volume 0.29 ± 0.03 mls and semen concentration7.766 ± 0.612 x10 9 than groups 1 and 2. The fertilizing ability, which was assessed through in vivo and in vitro sperm penetration assays revealed significantly higher number of sperm penetration holes (P < 0.05) in Groups 2 and 3, 160.97 ± 8.084 and 172.83 ± 7.647 ( in vivo ); 187.96 ± 8.121 and 189.16 ± 6.446 ( in vitro ) respectively. The local turkey toms could parallel their exotic counterpart under optimum environment, without the need for genetic hybridization and that 20% CP had more positive influence on the semen quality and fertilizing ability of indigenous Nigerian turkey toms followed by 16% CP with 12% CP exerting the least positive influence. Keywords: Artificial Insemination, Crude protein, Reproduction, Semen, Turkey toms

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Optimal nutrition, a key to addressing reproductive performance in Nigerian local turkey toms.

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 10 9 cells/ml, 0.21 ± 0.00 x 10 9 cells/ml and 0.21 ± 0.00 x 10 9 cells/ml for groups 1, 2 and 3 respectively. The mean ± SD extragonadal sperm reserves were, epididymis: 0.08 ± 0.00 x 10 9 cells/ml, 0.12 ± 0.01 x 10 9 cells/ml, 0.18 ± 0.00 x 10 9 cells/ml, and vas deferens: 2.00 ± 0.13 x 10 9 cells/ml, 2.82 ± 0.50 x 10 9 cells/ml and 3.75 ± 0.60 x 10 9 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

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A. I. Nwannenna

Papers

Optimal nutrition, a key to addressing reproductive performance in Nigerian local turkey toms.

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