ABSTRACT The objective of this study was to evaluate the effects of cocoa meal in feed concentrate on the spermatogenesis in sheep. Twenty-five uncastrated males were divided into four groups and fed concentrated feed, supplemented with 0, 10, 20, and 30% cocoa meal, respectively, for 150 days. At the end of this period, the animals were slaughtered, the testicles were collected for histological slides, and testicular morphometric assessments were conducted, including cell type quantification in the seminiferous epithelium, intrinsic spermatogenesis yield, Sertoli-cell index, total number of Sertoli cells (TNSC), TNSC per testicular gram, daily sperm production (DSP), DSP per testicular gram, testicular sperm reserve (TSR), and TSR per testicular gram. Data were subjected to normality analysis using the Shapiro-Wilk test, followed by the tests for each condition, at a significance level of 5%. The administration of cocoa meal did not alter the germinal epithelial cell population, except for the number of type-A spermatogonia, which was lower in the control group than in the group that received 20% supplementation. A difference was found in the ratio between the number of type-A spermatogonia and primary spermatocytes in pre-leptotene/leptotene, and in the ratio between Sertoli cells and primary spermatocytes in pre-leptotene/leptotene, the control group and the group that received 10% cocoa meal significantly varied from each other, but not in relation to the other evaluated percentages. The TNSC, TNSC/g, DSP, and TSR levels were diminished in the group that consumed 30% cocoa meal. The TNSC, DSP, and TSR exhibited a negative quadratic tendency. Supplementation with 10% cocoa meal improved the TNSC, DSP, and TSR of sheep.

Abstract The objective of this study was to evaluate the testicular biometric, seminal, and plasma testosterone levels in lambs subjected to an anti-GnRH vaccine as a method of castration. Thirty entire, crossbred Santa Inês male lambs were randomly distributed into three treatment (T): T1 was the control group, with the administration of 1 mL of saline solution subcutaneously (SC); 1.0 and 0.5 mL of an anti-GnRH vaccine were administered SC in T2 and T3, respectively. Testicular biometric variables, physical and morphological variables of semen, and plasma testosterone concentrations were evaluated. At D60, there was a reduction in testicular length, width, thickness, and scrotal circumference of the immunocastrated animals regardless of the vaccine dose used (P < 0.05). A reduction in semen physical variables at both dosages (P < 0.05) was observed, with azoospermia, in 80% and 70% of animals in the T2 and T3 groups, respectively. At D60, the immunocastrated animals also showed an increase in spermatozoa defects (P < 0.05), whereas plasma testosterone concentration decreased (P < 0.05). Immunocastration of lambs using the Bopriva vaccine at doses of 1.0 and 0.5 mL is efficient in inducing azoospermia in up to 80% of animals, although two doses in a 30-day interval are necessary for it to be an effective and safe method. Efficacy was demonstrated through a reduction in serum testosterone levels, testicular biometry, and seminal fluid analysis. Considering the efficacy of both doses in this study, we recommend using the lower dose (0.5 mL), which will allow for a 50% reduction in vaccine costs.

RESUMO O objetivo com o estudo foi avaliar o efeito da inclusão de semente de linhaça na dieta de machos caprinos sobre a resistência do sêmen frente ao processo de criopreservação. Foram utilizados 16 machos, os quais foram distribuídos em quatro grupos e receberam dieta suplementada com 0, 4, 8 e 12% de semente de linhaça, durante um período de 60 dias. As coletas de sêmen iniciaram 25 dias após o início do fornecimento das dietas. Apenas os ejaculados que apresentaram motilidade e vigor acima de 70% e 3, respectivamente, foram encaminhados para o processo de criopreservação. Após o descongelamento, o sêmen foi avaliado através dos testes de termorresistência, hiposmótico e de integridade acrossomal. Os dados foram submetidos à análise de variância e regressão a 5% de significância. Houve comportamento quadrático positivo para a motilidade progressiva aos 60, 120 e 180 minutos no teste de termoresistência (TTR), e comportamento quadrático positivo para o vigor espermático pós-descongelamento aos 120 e 180 minutos no TTR (P<0,05). Entretanto, obteve-se comportamento quadrático negativo para a integridade da membrana plasmática pelo Teste Hiposmótico (P<0,05) e houve diferença para o teste de integridade acrossomal, apresentando nível máximo ótimo de 3,25% de semente de linhaça para integridade acrossomal de 65,83% (P<0,05). Os resultados obtidos demonstram que a adição de 12% de semente de linhaça na dieta de reprodutores caprinos melhora a qualidade espermática pós-descongelamento.

ABSTRACT The objective of this study was to evaluate the effects of the inclusion of flaxseed in the diet of male goats on the resistance of semen to the cryopreservation process. Sixteen males were distributed in four groups and fed a diet supplemented with 0, 4, 8, and 12% of flaxseed for a period of 60 days. Only the ejaculates that presented motility and vigor above 70% and 3, respectively, were sent through the cryopreservation process. After thawing, the semen was evaluated through thermo resistance, hypoosmotic, and acrossomal integrity tests. The data were submitted to analysis of variance and regression at 5% of significance. There was positive quadratic behavior for motility after 60, 120, and 180 min in the thermoresistance test (TTR), and positive quadratic behavior for sperm vigor after thawing after 120 and 180 min in the TTR (P < 0.05). However, negative quadratic behavior was obtained for plasma membrane integrity according to the hypoosmotic test (P < 0.05) and there was a difference in the acrosomal integrity test, presenting an optimum maximum level of 3.25% of flaxseed for acrosomal integrity of 65.83% (P < 0.05). The results obtained demonstrated that the addition of as much as 12% of flaxseed to the diet of goat breeders improved post-thawing sperm quality.