Contagem celular e rendimento da espermatogênese em ovinos Santa Inês e mestiços Santa Inês e Dorper / Cell count and efficiency of spermatogenesis in ovine Santa Ines and mongrel Santa Inês and Dorper

With the objective to evaluate the efficiency spermatogenesis between sheep breeds, sixteen testicles,eight sheep, four belonging to the race Santa Ines and four of mongrel of Santa Inês and Dorper. After thecastration of animals, we obtained the gonadosomatic index. Generally the average diameter, relative frequencyof the stages in the life cycle of the seminiferous epithelium, yield of spermatogenesis, yield, meioticspermatogenic yield and efficiency of Sertoli cells. There were no significant differences between the races onthe phases of the cycle of the seminiferous epithelium, number of spermatids rounded, Sertoli cells, mitotic rateand effectiveness of Sertoli cells. However, the animals mongrel were higher as the population ofspermatogonia, primary spermatocytes in paquíteno and in pre-leptóteno/leptóteno, yield and meioticspermatogenic yield line. The study showed that animals mongrel of sheep breeds Santa Inês and Dorperpresented higher reproductive potential when compared with pure lambs of Santa Ines.

Histometria dos túbulos seminíferos em testículos de ovinos Santa Inês e mestiços Santa Inês e Dorper / Histometry of seminiferous tubules in testes of ovine Santa Ines and mongrel Santa Inês and Dorper

The morphometric measurements of the testicles is intended to measure the dimensions of constituenttestis parenchyma quantitatively evaluating spermatogenesis. This study aimed to analyze the spermatogenesisof sheep Santa Ines and crossbred Santa Ines and Dorper watching the racial crossing alter testis function. Weused eight sheep, four Santa Ines and four crossbreed of Santa Ines/Dorper. After castration the animals gavethe Gonadosomatic index. Gauged to volume ratio of testis compartments using a reticle. The constituents of thetubular casing were evaluated: Lamina propria, seminiferous epithelium of the lumen and interstitialcompartment constituents: Leydig cells, blood vessels and connective tissue. Only the tubular diameter andheight of the seminiferous epithelium showed significant differences, being higher for sheep Santa Ines. It wasconcluded that there was little difference in testicular morphometry of animals studied and it was found that theracial cross does not induce significant changes in parameters between groups.

Histometria dos túbulos seminíferos em testículos de ovinos Santa Inês e mestiços Santa Inês e Dorper / Histometry of seminiferous tubules in testes of ovine Santa Ines and mongrel Santa Inês and Dorper

The morphometric measurements of the testicles is intended to measure the dimensions of constituenttestis parenchyma quantitatively evaluating spermatogenesis. This study aimed to analyze the spermatogenesisof sheep Santa Ines and crossbred Santa Ines and Dorper watching the racial crossing alter testis function. Weused eight sheep, four Santa Ines and four crossbreed of Santa Ines/Dorper. After castration the animals gavethe Gonadosomatic index. Gauged to volume ratio of testis compartments using a reticle. The constituents of thetubular casing were evaluated: Lamina propria, seminiferous epithelium of the lumen and interstitialcompartment constituents: Leydig cells, blood vessels and connective tissue. Only the tubular diameter andheight of the seminiferous epithelium showed significant differences, being higher for sheep Santa Ines. It wasconcluded that there was little difference in testicular morphometry of animals studied and it was found that theracial cross does not induce significant changes in parameters between groups. (AU)

Contagem celular e rendimento da espermatogênese em ovinos Santa Inês e mestiços Santa Inês e Dorper / Cell count and efficiency of spermatogenesis in ovine Santa Ines and mongrel Santa Inês and Dorper

With the objective to evaluate the efficiency spermatogenesis between sheep breeds, sixteen testicles,eight sheep, four belonging to the race Santa Ines and four of mongrel of Santa Inês and Dorper. After thecastration of animals, we obtained the gonadosomatic index. Generally the average diameter, relative frequencyof the stages in the life cycle of the seminiferous epithelium, yield of spermatogenesis, yield, meioticspermatogenic yield and efficiency of Sertoli cells. There were no significant differences between the races onthe phases of the cycle of the seminiferous epithelium, number of spermatids rounded, Sertoli cells, mitotic rateand effectiveness of Sertoli cells. However, the animals mongrel were higher as the population ofspermatogonia, primary spermatocytes in paquíteno and in pre-leptóteno/leptóteno, yield and meioticspermatogenic yield line. The study showed that animals mongrel of sheep breeds Santa Inês and Dorperpresented higher reproductive potential when compared with pure lambs of Santa Ines.(AU)