The study investigated midpiece defects in sperm from a 5-year-old Brangus bull with a high rate of semen batch rejection, due to morphologically abnormal sperm, with no reduction in sperm kinematics. A comprehensive evaluation was conducted over a 16-month period, involving 28 ejaculates. Notably, despite the high proportion of midpiece defects (average 37.73%, from 3% to 58%), the study revealed stable sperm production, with no discernible differences in the kinematic data before and after cryopreservation. Electron microscopy identified discontinuities in the mitochondrial sheath, characteristic of midpiece aplasia (MPA). The anomalies were attributed to be of genetic origin, as other predisposing factors were absent. Additionally, the electron microscopy unveiled plasma membrane defects, vacuoles and chromatin decondensation, consistent with previous findings linking acrosome abnormalities with midpiece defects. The findings underscored the necessity of conducting thorough laboratory evaluations before releasing cryopreserved semen for commercialization. Despite substantial morphological alterations, the initial semen evaluation data indicated acceptable levels of sperm kinematics, emphasizing the resilience of sperm production to severe morphological changes. This case report serves as a contribution to the understanding of midpiece defects in bull sperm, emphasizing the need for meticulous evaluation and quality control in semen processing and commercialization.
Cryopreservation , Semen Analysis , Semen Preservation , Spermatozoa , Male , Animals , Cryopreservation/veterinary , Cattle , Semen Preservation/veterinary , Semen Analysis/veterinary , Spermatozoa/abnormalities , Spermatozoa/physiology , Biomechanical Phenomena , Sperm Midpiece , Sperm Motility , Acrosome
O objetivo deste estudo foi avaliar o efeito da somatotropina recombinante bovina (rbST) sobre os marcadores do metabolismoenergético, proteico, mineral e hepático de touros mantidos em semiconfinamento. Foram utilizados 20 touros de raçasAberdeen Angus e Brangus, sendo divididos aleatoriamente em dois grupos (Placebo e rbST), para que no Placebo fosseadministrado via subcutânea duas doses de NaCl, 0,9% e no rbST fosse administrado o rbST (Lactotropin®). Foram realizadascinco coletas de sangue, com intervalo de 14 dias, para avaliação da concentração de triacilgliceróis e colesterol comomarcadores energéticos, ureia, como indicador proteico, fosfatase alcalina e fósforo como marcadores minerais e asenzimas aspartato aminotransferase (AST) e a gama glutamiltransferase (GGT) como indicadoras da função hepática. Aaplicação de rbST não influenciou os marcadores energéticos, minerais, e proteico, exceto a enzima hepática GGT (P 0,05).Estes resultados indicam que a utilização do rbST em touros não alterou o metabolismo, pois os parâmetros avaliadosmantiveram-se dentro dos padrões considerados fisiológicos para a espécie.
The aim of this study was to evaluate the effect of recombinant bovine somatotropin (rbST) on metabolic markers for energy, protein, mineral and hepatic metabolism of sires kept grazing and receiving concentrate. Twenty sires Aberdeen Angus and Brangus used for this experiment were divided in two groups (Placebo and rbST). The group Placebo received subcutaneous administration of NaCl, 0.9% and rbST receive rbST twice. Five blood collections with 14 days of interval were made for evaluation of triglyceride and cholesterol as energetic metabolism markers, urea, as proteic marker, alkaline phosphatase and phosphorus as minerals markers and aspartate aminotransferase (AST) and gamma glutamyltransferase (GGT) as indicators of the hepatic function. The rbST did not influence the energetic, mineral and proteic markers, except the hepatic enzyme GGT (P<0,05). These results indicated that the use of rbST in sires did not affect metabolism, therefore evaluated parameters remaining in the physiological range for the specie.
Animals , Cattle , Cattle/abnormalities , Cattle/metabolism , Growth Hormone/analysis , Growth Hormone/adverse effects
Os touros compõem uma importante categoria animal nos sistemas de produção ligados à pecuária, sendo responsáveis por uma considerável parcela do melhoramento genético de um rebanho. Porém, poucos estudos relacionados às condições metabólicas desta categoria vêm sendo conduzidos. O objetivo deste estudo foi avaliar o perfil metabólico de touros em três períodos distintos do ciclo reprodutivo, sendo antes da estação reprodutiva, durante e após a estação reprodutiva. Este experimento foi conduzido em uma propriedade da região Sul do Rio Grande do Sul com 23 touros. Os marcadores bioquímicos utilizados para avaliar o perfil metabólico foram os seguintes: glicose, colesterol, para determinar o perfil energético; albumina, uréia, como marcadores protéicos e a enzima aspartato aminotransferase (AST) como indicador da função hepática. Os resultados demonstraram que houve diferença (p < 0,05) de todos marcadores metabólicos avaliados durante os diferentes períodos do ciclo produtivo, indicando que houve variação na disponibilidade de alimento, possivelmente capaz de gerar perdas produtivas e reprodutivas que podem ser solucionadas com suplementação protéica ou melhoramento do campo nativo.
Bulls are an important category in cattle production systems, being responsible for a considerable part of genetic improvement in a herd. However, few studies about the metabolic conditions of this category have been done. The objective of this study was to evaluate the metabolic profile of bulls in three different phases of the reproductive cycle, that are, before, during and after the breeding season. This study was conducted with 23 bulls, in a farm in southern Rio Grande do Sul. The biochemical markers used for the evaluations were: glicose and cholesterol, to determine energetic profile; albumin and urea to determine protein profile and enzyme aspartate aminotransferase (AST) as an indicator of liver functionality. There was a difference (p < 0,05) in all metabolic markers evaluated during the different phases of the productive cycle, showing that there was a variation in food availability, which could lead to productive and reproductive losses. This could be improved by protein supplementation and pasture improvement.
Animals , Adult , Reproductive Behavior , Biomarkers/analysis , Metabolism , Analysis of Variance , Animal Feed , Cattle
