The Influence Of Seasons On Semem Quality In Beef Bulls

The effects of four seasons on semen quality and quantity in four breeds beef bulls were studied. The solstices and equinoxes (December, March, June and September) defined the beginning of each season (Winter, Spring, Summer and Autumn) and the four beef breed were Semmental, Charolais, Linmousin and Piedmont. The study demonstrated the results as follow:(1) The seasonal effects of semen valume was no signaficant differencefor Semmental, Charolais, Linmousin and Piedmont bull(P>0.05).(2) The mean spermatozoa progressive motility (SPM)of four breeds bull were 0.70±0.00, 0.57±0.08 ,0.64±0.03 and 0.69±0.01 in spring, summer,autumn and winter respectively. SPM in summer was obviously lower than spring, autumn and winter(P<0.01). For different breeds, summer had more great negative effect on Charolais than other breeds in the view of the mean spermatozoa progressive motility .(3) The post-thaw progressive motility(PTPM)of the frozen semen for four breeds bull were 0.38±0.02, 0.28±0.05, 0.33±0.03 and 0.38±0.01 in spring, summer,autumn and winter respectively. PTPM in summer was obviously lower than spring, autumn and winter(P<0.01). For different breeds, summer had more great negative effect on Charolais l than other breeds in this view.(4) The semen concentration of four breeds bull in summer was 10.59±3.18 which were signaficantly lower than spring (17.33±1.55; P<0.01), winter(16.08±2.24; P<0.01) and autumn( 12.94±2.92; P<0.05).(5)The percentage of malformation frozen sperm for four breeds bull were 8.35±4.19, 21.89±3.89, 18.43±3.26 and 14.01±0.69 in spring, summer,autumn and winter respectively. The percentage of malformation frozen sperm in summer was greatest high than spring, autumn and winte(rP<0.01). For different breeds, summer had more great negative effect on Charolais than other breeds for the percentage of malformation sperm. (6) The percentages of sperms with intact acrosomes of four breeds bull were 69.78±1.69, 47.49±4.99, 55.36±4.75 and 66.78±1.68 in spring, summer,autumn and winter, respectively. It was obviously lower in summer than spring and winter(P<0.01),and also lower than autumn(P<0.05). For different breeds, summer had more great negative effect on Charolais than other breeds in the view of the percentages of sperms with intact acrosomes.