关键词: 公猪, 睾丸参数, 精液质量, 日龄

Abstract: In order to clarify the significance of boar testicles in selection, the developmental rule of testicular and semen quality parameters and their correlation between them were studied. In this experiment, 936 boars distributed in the age of 280～1 409 d were selected as materials including 589 Duroc, 233  Landrace and 114 Yorkshire. Multivariate analysis of testicular  and semen quality parameters was performed by using a general linear model with fixed factors of variety and day-age grouping. Time-development curve fitting of total testicular volume and effective sperm count was carried out separately using a quadratic model depending on the variety. Partial correlation analysis between testicular  and semen quality parameters was performed by controlling age variables. Comparison of testicular size parameters showed Duroc> Yorkshire > Landrace, in which Duroc and Yorkshire were not significantly different (P>0.05), but both were extremely significant (P<0.01) higher than Landrace. In terms of semen quality, Landrace was better than Duroc, and Duroc was better than Yorkshire, but the difference was not significant (P>0.05). However, in the volume, density, vigor and deformity rate, the differences were significant (P>0.05) or extremely significant (P<001) among the three breeds of boars. The testicles increased first and then atrophied with aging, and the overall quality of semen decreased with aging. The size parameters of the testes in three boar breeds were positively correlated with the amount of semen and the number of effective sperm, and most of them were significant (P<0.05) or extremely significant (P<0.01). At the same age, the testicular size of the three breeds of boars was Duroc> Landrace> Yorkshire, in which the fact that Landrace was  universally greater than Yorkshire. Taken together, the results of the semen quality comparison of the three varieties showed Landrace was better than Duroc, Duroc was better than Yorkshire, and Landrace was superior to Yorkshire which was universal.  The age when boar testicular atrophy begins could be used to establish a boar elimination time. When selecting a boar, one with the larger testicl should be focused on.

Key words: boar, testicular, semen quality, age of day