Master of Science (MS)
Animal Science (Animal, Dairy, and Poultry Sciences)
The duration of frozen semen storage had no effect on pregnancy rates (60%, 61% and 61%, respectively) in Angus females inseminated with semen from 25 Angus bulls from Time Frames 1 (1960-1975), 2 (1976-1991) and 3 (1992-2006). Pregnancy rates were not different for beef females inseminated with semen from Time Frames 1, 2 and 3 (55%, 62% and 55%, respectively). There were no differences for total and progressive sperm motility across Time Frames 1 (42% and 29%), Time Frame 2 (51% and 38%) and Time Frame 3 (55% and 41%) and percentage of normal and abnormal sperm from bulls in Time Frames 1 (80% and 19%), Time Frame 2 (76% and 23%) and Time Frame 3 (71% and 28%). No differences were detected between sperm concentrations/breeding unit for bulls within Time Frame 1 and Time Frame 2 or between Time Frame 1 and Time Frame 3. In contrast, a significant difference (P<0.05) was detected for sperm concentration for bulls within Time Frame 2 (59.9 x 106/mL) and Time Frame 3 (37.1 x 106/mL). Within these bulls regardless of Time Frame, no differences were detected in total sperm and progressive sperm motility for bulls categorized as being high (54% and 41%), moderate (51% and 39%) or low (46% and 31%) fertility rates. Brangus F1 females had higher (P<0.05) chute behavior scores when compared with Bons Mara, Romsinuano, Braford, Brangus, Beefmaster and Angus females. Furthermore, Brangus F1, Brangus and Beemaster females had higher (P<0.05) mean chute exit velocities when compared with Angus, Romosinuano, Bons Mara and Braford females Chute behavior scores were not significantly different for pregnant and nonpregnant females. A significantly higher chute exit velocity was noted for nonpregnant females when compared with pregnant females. Significant correlations (r = 0.58, P <0.05) was detected for chute exit velocity on day 0 and day 7. Furthermore, a significant positive correlation (r = 0.28) was detected between mean subjective behavior chute scores and mean chute exit velocity.
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Carwell, David Barry, "Pregnancy Rates in Beef Cattle Artifically Inseminated with Frozen-Thawed Aged Beef Semen" (2010). LSU Master's Theses. 775.
Gentry, Jr., Glen T.