Relationship of residual feed intake with semen parameters and testicular ultrasound of Nellore bulls

The objective of this study was to evaluate characteristics of the testicular parenchyma and vascular parameters of the pampiniform plexus obtained by ultrasound, semen quality parameters, and sperm freezability in Nellore bulls classified based on residual feed intake (RFI). Twenty-seven bulls (21.82±0.88 months of age) evaluated for feed efficiency were sampled for the study, including 15 with low RFI (−0.592±0.09 kg dry matter/day) and 12 with high RFI (0.792±0.10 kg dry matter/day). In ultrasound and Doppler assessment, the most efficient animals (low RFI) showed higher pulsatility and resistive indexes, as well as a tendency towards greater heterogeneity of the testicular parenchyma (0.625±0.032 vs. 0.508±0.032, 1.012±0.072 vs. 0.802±0.072, and 12.9±0.96 vs. 10.2±0.96, respectively, for low vs. high RFI). However, these animals tended to have lower peak diastolic velocity (5.19±0.50 for low RFI vs. 6.54±0.50 for high RFI). Analysis of fresh semen showed a lower percentage of minor defects in low RFI animals (2.67±1.19%) compared with high RFI animals (8.10±1.19%), without differences in the other parameters in fresh or thawed semen and after thermoresistance testing. Evaluation of flow cytometry parameters showed a higher quality of mitochondrial respiration in semen samples of low RFI animals (22.04±2.50%) compared with high RFI animals (12.29±2.71%). Therefore, although RFI exerts an effect on the Doppler parameters of the pampiniform plexus, it is not sufficient to affect the quality of fresh or thawed semen.(AU)

Cinética e integridade de espermatozoides caprinos criopreservados utilizando Red Cushion® como estratégia de proteção espermática durante a centrifugação do sêmen / Kinetics and integrity of cryopreserved goat sperm using Red Cushion® as a strategy to sperm protection during semen centrifugation

Objetivou-se avaliar o efeito do gradiente de Iodixanol (Red Cushion®, RC) como método deproteção espermática durante a centrifugação (CE) do sêmen caprino destinado à criopreservação. Foramrealizadas colheitas de sêmen de cinco reprodutores caprinos da raça Anglo Nubiana (N= cincoejaculados/bode). Os ejaculados foram divididos em três grupos experimentais: GC (Controle); G1 (CEutilizado 1ml de RC) e G2 (foi utilizado 0,5mL de RC, misturado ao pellet espermático após a CE). Asamostras foram centrifugadas, diluídas, envasadas e criopreservadas. A cinética espermática foi avaliada porsistema computadorizado de análise (CASA) após a descongelação e pós-teste de termorresistência (TTR), efoi avaliada a integridade de membrana plasmática e acrossomal (MPAI, %). Não foram observadasdiferenças para a motilidade total (p=0,1849) avaliada pós-descongelação (GC=45,1%, G1=51,86% eG2=55,28%) ou pós-TTR (GC=10,32%, G1=11,44% e G2=13,16%), bem como para nenhum outroparâmetro cinético avaliado. Também não foram encontradas diferenças para a MPAI (GC=43,70% ±16,60; G1=36,68 ± 17,40; G2=41,72 ± 14,76; p=0,2523). Conclui-se que a utilização de Red Cushion®não promove nenhum benefício à manutenção da cinética e integridade de espermatozoides caprinossubmetidos a centrifugação previamente ao processo de criopreservação do sêmen.(AU)

The aim of this study was to evaluate the efficacy of iodixanol gradient centrifugation (RedCushion®, RC) as a method of protection of goat semen submitted to centrifugation previously tocryopreservation process. Semen were collected from five Anglo Nubian goats (n = five ejaculates/goat).The ejaculates were divided into three experimental groups: GC (Control; conventional centrifugation);G1 (centrifugation using 1ml RC) and G2 (centrifugation using 0.5 mL RC, mixed to sperm pellet beforethe cryopreservation). Samples were centrifuged (CE) at 600xg for 10 minutes, diluted, packed andcryopreserved. Sperm kinetics were evaluated using a computer assisted semen analysis (CASA) afterthawing and after thermoresistance test (TTR), and the integrity of the plasma and acrosomal membranewas evaluated (MPAI, %). No differences were observed for total motility (P =0.1849) assessed afterthawing (GC=45.1%, G1=51.86% and G2=55.28%) or post-TTR (GC=10.32%, G1=11.44% andG2=13.16%), as well as for the other kinetic parameters analyzed. Furthermore, no differences for MPAI(CG =43.70% ± 16.60; G1=36.68 ± 17.40; G2=41.72 ± 14.76; P=0.2523) were found comparing thedifferent groups. In conclusion, Red Cushion® was not able to improve the kinetics and integrity of thegoat semen submitted to the cryopreservation process.(AU)

Cinética e integridade de espermatozoides caprinos criopreservados utilizando Red Cushion® como estratégia de proteção espermática durante a centrifugação do sêmen / Kinetics and integrity of cryopreserved goat sperm using Red Cushion® as a strategy to sperm protection during semen centrifugation

Objetivou-se avaliar o efeito do gradiente de Iodixanol (Red Cushion®, RC) como método deproteção espermática durante a centrifugação (CE) do sêmen caprino destinado à criopreservação. Foramrealizadas colheitas de sêmen de cinco reprodutores caprinos da raça Anglo Nubiana (N= cincoejaculados/bode). Os ejaculados foram divididos em três grupos experimentais: GC (Controle); G1 (CEutilizado 1ml de RC) e G2 (foi utilizado 0,5mL de RC, misturado ao pellet espermático após a CE). Asamostras foram centrifugadas, diluídas, envasadas e criopreservadas. A cinética espermática foi avaliada porsistema computadorizado de análise (CASA) após a descongelação e pós-teste de termorresistência (TTR), efoi avaliada a integridade de membrana plasmática e acrossomal (MPAI, %). Não foram observadasdiferenças para a motilidade total (p=0,1849) avaliada pós-descongelação (GC=45,1%, G1=51,86% eG2=55,28%) ou pós-TTR (GC=10,32%, G1=11,44% e G2=13,16%), bem como para nenhum outroparâmetro cinético avaliado. Também não foram encontradas diferenças para a MPAI (GC=43,70% ±16,60; G1=36,68 ± 17,40; G2=41,72 ± 14,76; p=0,2523). Conclui-se que a utilização de Red Cushion®não promove nenhum benefício à manutenção da cinética e integridade de espermatozoides caprinossubmetidos a centrifugação previamente ao processo de criopreservação do sêmen.

The aim of this study was to evaluate the efficacy of iodixanol gradient centrifugation (RedCushion®, RC) as a method of protection of goat semen submitted to centrifugation previously tocryopreservation process. Semen were collected from five Anglo Nubian goats (n = five ejaculates/goat).The ejaculates were divided into three experimental groups: GC (Control; conventional centrifugation);G1 (centrifugation using 1ml RC) and G2 (centrifugation using 0.5 mL RC, mixed to sperm pellet beforethe cryopreservation). Samples were centrifuged (CE) at 600xg for 10 minutes, diluted, packed andcryopreserved. Sperm kinetics were evaluated using a computer assisted semen analysis (CASA) afterthawing and after thermoresistance test (TTR), and the integrity of the plasma and acrosomal membranewas evaluated (MPAI, %). No differences were observed for total motility (P =0.1849) assessed afterthawing (GC=45.1%, G1=51.86% and G2=55.28%) or post-TTR (GC=10.32%, G1=11.44% andG2=13.16%), as well as for the other kinetic parameters analyzed. Furthermore, no differences for MPAI(CG =43.70% ± 16.60; G1=36.68 ± 17.40; G2=41.72 ± 14.76; P=0.2523) were found comparing thedifferent groups. In conclusion, Red Cushion® was not able to improve the kinetics and integrity of thegoat semen submitted to the cryopreservation process.