Sheep spermatogenesis is affected by the nutritional levels of cocoa meal, a byproduct of cocoa butter manufacturing rich in theobromine and caffeine

Abstract

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.

Keywords

• Sertoli cells
• spermatogonia
• testicular morphometry