Influence of hay feeding method, supplement moisture, or access time on intake and waste by beef cows.

Experiments were performed to determine the effects of feeding method and hay processing (Experiment 1), energy supplement moisture content and feeding method (Experiment 2), and access time to hay (Experiment 3) on cow body weight (), dry matter intake (), and hay or energy supplement intake and waste. Experiment 1 was designed as a 4 × 4 Latin Square using 48 multiparous, late-gestating, Angus cows (626 kg initial BW). Cows were stratified by age and BW into four treatment groups ( = 12 cows/group); treatment groups were then initially assigned randomly to treatments in a sequence of preset Latin Square periods.

Comparative studies on bull and stallion seminal DNase activity and interaction with semen extender and spermatozoa.

We performed a series of comparative studies of bull and stallion seminal plasma (SP) and its role on sperm-neutrophil binding as well as the interaction between semen extender and seminal DNase. Because of contrasting roles of SP on sperm-neutrophil binding between horses and cattle, it was suspected there were some species-specific differences on sperm interaction with SP proteins due to the variations in the natural location of semen deposition (uterus compared to vagina). Bull frozen-thawed sperm removed from egg yolk extender showed similar results to fresh sperm, but this also caused extensive sperm agglutination unless SP or egg yolk was included.

Species-specific interaction of seminal plasma on sperm-neutrophil binding.

Bovine semen is naturally deposited in the vagina and spermatozoa migrate through the cervix into the uterus leaving the bulk of seminal plasma (SP) behind. In equine, both spermatozoa and SP are deposited directly in the uterus and SP reduces sperm binding to neutrophils and prevents the formation of DNA-based neutrophil extracellular traps (NETs). We investigated the role of bovine SP on sperm-neutrophil binding using the four most common bovine semen extenders.