Vaccines against sexually transmitted diseases

Human sexually transmitted infections are prevalent throughout the world. Several have been associated with adverse pregnancy outcome and increased susceptibility to HIV infection, in addition to the discomfort of inflammation of the genital tract. Yet vaccines to protect against the infection at the genital mucosa are not available. Hepatitis B is an exception, but this virus becomes systemic and protection may be at the systemic level. Sexually transmitted diseases (STDs) have long been associated with reproductive failure in cattle. These infections cause considerable economic loss, which has been a stimulus to investigation. Consequently, vaccines and mechanisms of immune protection have been studied quite thoroughly. The results obtained with two commercially available vaccines will be used to illustrate principles of protective immunity against STDs. Both Campylobacter fetus subsp. venerealis and Tritrichomonas foetus are only transmitted sexually and both cause reproductive failure in cattle

Effects of Production System on Cow and Calf Performance

Limited traditional forage resources have prompted interest for alternative cow-calf production systems. This study evaluated the effects of two winter cow-calf production systems (cornstalk grazing and dry-lot feeding) on cow-calf performance in a summer-calving, intensively managed cowherd at two locations. Grazing cow-calf pairs on cornstalks resulted in similar or lower ending BW of cows and lower ADG of calves when compared to cow-calf pairs wintered in the dry-lot. A partial budget of incorporating winter cornstalk grazing into an intensive production system suggests that cows wintered on cornstalks may be $137 more profitable compared to cows wintered in the dry-lot

Effects of Production System on Cow and Calf Performance

Limited traditional forage resources have prompted interest for alternative cow-calf production systems. This study evaluated the effects of two winter cow-calf production systems (cornstalk grazing and dry-lot feeding) on cow-calf performance in a summer-calving, intensively managed cowherd at two locations. Grazing cow-calf pairs on cornstalks resulted in similar or lower ending BW of cows and lower ADG of calves when compared to cow-calf pairs wintered in the dry-lot. A partial budget of incorporating winter cornstalk grazing into an intensive production system suggests that cows wintered on cornstalks may be $137 more profitable compared to cows wintered in the dry-lot

Effects of Production System on Cow and Calf Performance

Limited traditional forage resources have prompted interest for alternative cow-calf production systems. This study evaluated the effects of two winter cow-calf production systems (cornstalk grazing and dry-lot feeding) on cow-calf performance in a summer-calving, intensively managed cowherd at two locations. Grazing cow-calf pairs on cornstalks resulted in similar or lower ending BW of cows and lower ADG of calves when compared to cow-calf pairs wintered in the dry-lot. A partial budget of incorporating winter cornstalk grazing into an intensive production system suggests that cows wintered on cornstalks may be $137 more profitable compared to cows wintered in the dry-lot

Effects of Production System on Cow and Calf Performance

Limited traditional forage resources have prompted interest for alternative cow-calf production systems. This study evaluated the effects of two winter cow-calf production systems (cornstalk grazing and dry-lot feeding) on cow-calf performance in a summer-calving, intensively managed cowherd at two locations. Grazing cow-calf pairs on cornstalks resulted in similar or lower ending BW of cows and lower ADG of calves when compared to cow-calf pairs wintered in the dry-lot. A partial budget of incorporating winter cornstalk grazing into an intensive production system suggests that cows wintered on cornstalks may be $137 more profitable compared to cows wintered in the dry-lot

Effects of Production System on Cow and Calf Performance

Limited traditional forage resources have prompted interest for alternative cow-calf production systems. This study evaluated the effects of two winter cow-calf production systems (cornstalk grazing and dry-lot feeding) on cow-calf performance in a summer-calving, intensively managed cowherd at two locations. Grazing cow-calf pairs on cornstalks resulted in similar or lower ending BW of cows and lower ADG of calves when compared to cow-calf pairs wintered in the dry-lot. A partial budget of incorporating winter cornstalk grazing into an intensive production system suggests that cows wintered on cornstalks may be $137 more profitable compared to cows wintered in the dry-lot

Evaluation of Corn Distillers Solubles on Growing Steer Performance

A growing study evaluated increasing inclusions of corn distillers solubles (CDS) at 10, 20, 30, and 40%, or increasing wet distillers grains plus solubles (WDGS) at 10, 20, 30, and 40% compared to a corn control. Corn was replaced by CDS or WDGS in each forage-based diet. Increasing CDS resulted in a quadratic increase for both DMI and F:G. Increasing WDGS linearly increased both DMI and ADG with no effect on F:G. The energy value of CDS is less than that of corn, whereas WDGS had an energy value similar to corn in growing diets with 50% brome hay. A 73.7% TDN value was determined for CDS at 40% inclusion in forage-based diets

Impact of Grazing Spring Rye on Subsequent Crop Yields and Profitability

Steers (729 ± 19 lb BW) grazed in two November-planted cereal rye fields for 22 d in April, either with or without an ionophore in their free choice mineral supplement. Subsequent corn yields were measured to assess impact of planting cereal rye as a cover crop (not grazed) or grazing the rye compared to a no rye control. There was no statistical impact of rye or grazing on subsequent corn yield. Supplying an ionophore in the mineral did not uniformly improve gains across fields. However, gains were high at 3.2 lb/d and were able to offset the cost of planting rye

Optical Propagation and Communication

Contains reports on four research projects.National Science Foundation (Grant ECS81-20637)U.S. Navy - Office of Naval Research (Contract N00014-81-K-0662)U.S. Army Research Office - Durham (Contract DAAG29-80-K-0022)U.S. Navy - Office of Naval Research (Contract N00014-80-C-0941