ABSTRACT
Despite being the most important form of biotechnology in animal reproduction, artificial insemination was used in about 23% of Brazilian bovine herds in 2021. This is due to the variability of results caused by varying bull fertility and body condition of the cows. This study aimed to correlate the fertility indices of bulls with qualitative attributes of the semen. Semen samples from 28 bulls (Nellore and Angus) were used to evaluate postthaw sperm morphology and kinetics using conventional analysis, image-based flow cytometry (IBFC) and computer-assisted semen analysis (CASA). The fertility index was effective in separating bulls into 4 different fertility classes (P < 0.001), and fertility rates in timed artificial insemination (TAI) remained constant between the cows' fertility categories (P < 0.001) and in the different grades of female body condition (P < 0.005). After partial least squares regression (PLS) analysis, four models were proposed with different variables. The coefficients of determination for the conventional analysis, CASA, and IBCFC models were 0.154, 0.380, and 0.259, respectively. The composite model, including select IBFC and CASA parameters, showed a greater R2 (0.481) with progressive motility, average speed (VAP, µm/s), membrane integrity, and mitochondrial potential, showing a positive effect. Linear speed (VSL, µm/s) and acrosomal integrity had a negative effect on bull fertility indices. Bulls classified by the fertility index attained dispersed pregnancy rates in different cow body condition score (BCS) classes, and the sperm quality pattern was consistent with this classification. In conclusion, this novel composite model including CASA and IBFC parameters improves the prediction of bull fertility used in TAI.
ABSTRACT
The aim of the present study was to evaluate the effect of two doses of acetonide triamcinolone (TRI) at two distinct moments of gestation in the pre induction of parturition. Embryo recipients pregnant of the in vitro produced embryo were utilized as experimental model. A total of 175 pregnant embryo recipients were assigned into one of the four groups according to gestational period (280 or 285 days) and utilized dose of the TRI (1mg/60Kg or 1mg/100kg of body weight). The synchronization and assistance rates of the calving, the viability and body weight of calves at calving as well as retained placenta rate were evaluated. The TRI dose did not effect any variables responses (p>0.05). Least spread of the calving moment was observed in the recipients treated at the 280 days of gestation (p?0.05). The cow calving calf with ?42kg needed more assistance to calving (p?0.05) and these calves had lower viability than calves with
Este estudo teve como objetivo avaliar o efeito de diferentes doses e momentos da gestação para a administração do acetato de triancinolona (TRI) na pré-indução de partos. Utilizaram-se como modelo experimental receptoras de embriôes Nelore produzidos in vitro (PIV). Cento e setenta e cinco receptoras gestantes foram distribuídas em quatro grupos experimentais de acordo com o tempo gestacional (280 ou 285 dias) e a dose de TRI (1mg/60 Kg ou 1mg/100 Kg de Peso Vivo). Avaliaram-se o momento da gestação, as taxas de sincronização e de assistência aos partos, a viabilidade e o peso dos bezerros e ainda a taxa de retenção de placenta. A dose de TRI não alterou os parâmetros avaliados (p>0,05). Houve maior sincronização dos partos (p
ABSTRACT
The aim of the present study was to evaluate the effect of two doses of acetonide triamcinolone (TRI) at two distinct moments of gestation in the pre induction of parturition. Embryo recipients pregnant of the in vitro produced embryo were utilized as experimental model. A total of 175 pregnant embryo recipients were assigned into one of the four groups according to gestational period (280 or 285 days) and utilized dose of the TRI (1mg/60Kg or 1mg/100kg of body weight). The synchronization and assistance rates of the calving, the viability and body weight of calves at calving as well as retained placenta rate were evaluated. The TRI dose did not effect any variables responses (p>0.05). Least spread of the calving moment was observed in the recipients treated at the 280 days of gestation (p?0.05). The cow calving calf with ?42kg needed more assistance to calving (p?0.05) and these calves had lower viability than calves with
Este estudo teve como objetivo avaliar o efeito de diferentes doses e momentos da gestação para a administração do acetato de triancinolona (TRI) na pré-indução de partos. Utilizaram-se como modelo experimental receptoras de embriôes Nelore produzidos in vitro (PIV). Cento e setenta e cinco receptoras gestantes foram distribuídas em quatro grupos experimentais de acordo com o tempo gestacional (280 ou 285 dias) e a dose de TRI (1mg/60 Kg ou 1mg/100 Kg de Peso Vivo). Avaliaram-se o momento da gestação, as taxas de sincronização e de assistência aos partos, a viabilidade e o peso dos bezerros e ainda a taxa de retenção de placenta. A dose de TRI não alterou os parâmetros avaliados (p>0,05). Houve maior sincronização dos partos (p
ABSTRACT
At in vitro embryo production sperm selection techniques are used, one of them is Percoll® density-gradient. The aim with this study was to evaluate the plasmatic membrane (eosin-nigrosin), acrosomal (trypan blue-Giemsa; fluorescein isothiocyanate conjugated peanut agglutinin lecitin/propidium iodide (FITC-PNA/PI) and chromatin (toluidine blue) integrity, in frozen bovine spermatozoa. Twenty nine samples were analysed at post-thaw (PD) and post-Percoll® moments. Variable expressed in percentage were submitted to ANOVA and used Tuckeys test for mean comparison. The association between variables was made by Pearsons correlation. There were significant differences (p
Na produção in vitro de embriões, técnicas de seleção espermática são usadas, dentre elas, o gradiente descontínuo de Percoll®. O objetivo foi avaliar a integridade da membrana plasmática (eosina-nigrosina), do acrossomo (trypan blue- Giemsa TBG, lecitina do amendoim conjugada ao isotiocianato de fluoresceína associado ao iodeto de propídeo - Fitc-PNA/PI) e da cromatina (azul de toluidina), em espermatozóide bovino congelado. Vinte e nove amostras foram analisadas nos momentos pós-descongelação (PD) e pós-Percoll® (PP). As variáveis expressas em porcentagem foram submetidas à análise de variância e foi empregado o teste de Tuckey para a comparação entre médias. O estudo da associação entre variáveis foi feito pelo teste de correlação de Pearson. Constataram-se, entre os momentos PD e PP, diferenças significativas (p
ABSTRACT
At in vitro embryo production sperm selection techniques are used, one of them is Percoll® density-gradient. The aim with this study was to evaluate the plasmatic membrane (eosin-nigrosin), acrosomal (trypan blue-Giemsa; fluorescein isothiocyanate conjugated peanut agglutinin lecitin/propidium iodide (FITC-PNA/PI) and chromatin (toluidine blue) integrity, in frozen bovine spermatozoa. Twenty nine samples were analysed at post-thaw (PD) and post-Percoll® moments. Variable expressed in percentage were submitted to ANOVA and used Tuckeys test for mean comparison. The association between variables was made by Pearsons correlation. There were significant differences (p
Na produção in vitro de embriões, técnicas de seleção espermática são usadas, dentre elas, o gradiente descontínuo de Percoll®. O objetivo foi avaliar a integridade da membrana plasmática (eosina-nigrosina), do acrossomo (trypan blue- Giemsa TBG, lecitina do amendoim conjugada ao isotiocianato de fluoresceína associado ao iodeto de propídeo - Fitc-PNA/PI) e da cromatina (azul de toluidina), em espermatozóide bovino congelado. Vinte e nove amostras foram analisadas nos momentos pós-descongelação (PD) e pós-Percoll® (PP). As variáveis expressas em porcentagem foram submetidas à análise de variância e foi empregado o teste de Tuckey para a comparação entre médias. O estudo da associação entre variáveis foi feito pelo teste de correlação de Pearson. Constataram-se, entre os momentos PD e PP, diferenças significativas (p