Correlations among semen quality traits and scrotal circumference of sires of the Gyr breed

[摘要] - Data related with semen characteristics such as volume (VOL), gross motility (TURB), motility (MOT), vigor (VIG), concentration (CONC), major defects (DMA) and minor defects (DME) from 807 semen output (CS) of 105 sires of the Gyr breed selected for milk production, and their measurements of scrotal circumference (CE) were used to study factors that affect these traits and the correlations among them. Uni and bivariate animal models that included the fixed effects of AI company, year and season of CS or CE measurement, age at CS or CE measurement, and random animal (bull) effect were used to evaluate the effects of these source of variation and the correlation between those traits. AI company and sire had a significant effect on all traits. Age affected only CE, TURB and NEMOV (= VOL x CONC x MOT). Repetabilities estimated by univariate model ranged from 0.23 for CONC to 0.70 for TURB. In general, phenotypic correlations, estimated by bivariate model were in a favorable direction. Pearson correlation between CE and all other traits ranged from -0.19 to 0.35. The recorded correlations, in general in a favorable direction, suggested that CE could be used as an elimination trait of sire to be pre-selected as a semen donor.

[学科分类] 兽医学

[关键词] correlations;repeatability;scrotal circumference;semen quality     IntroduçãoA contribuição do touro;seja por monta natural ou pelo uso da inseminação artificial;para a eficiência reprodutiva e a produção de leite e/ou carne;é de grande importância;porque cada touro representa a metade da composição genética de suas progênies