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A 167-d feedlot study was conducted to evaluate feeding increasing levels of dry distillers grains plus solubles (DDGS) to finishing cattle and the impact on performance and profitability. Crossbred steer calves (n = 240, BW = 306 ± 24.5 kg) were used in 30 pens with dietary treatments of 0, 10, 20, 30, and 40% DDGS dietary inclusion (DM basis). Quadratic(More)
Supplements and growth promotants containing steroid hormones are routinely administered to beef cattle to improve feeding efficiency, reduce behavioral problems, and enhance production. As a result, beef cattle manure will contain both synthetic steroids as well as a range of endogenous steroids including androgens, estrogens, and progestogens. A two-year(More)
The ability to predict the effects of extreme climatic variables on livestock is important in terms of welfare and performance. An index combining temperature and humidity (THI) has been used for more than 4 decades to assess heat stress in cattle. However, the THI does not include important climatic variables such as solar load and wind speed (WS, m/s).(More)
Experiments were conducted to evaluate the heat tolerance of the following breeds: Hereford (H), Brahman (B), H x B, H x Boran (H x Bo), and H x Tuli (H x T). Heat tolerance was evaluated in a climatically controlled room (Exp. 1) and under summer environmental conditions (Exp. 2) by comparing rectal temperatures (RT), respiration rates (RR), and sweating(More)
Ten years of calving records were examined from Bos taurus crossbred cows (mean of 182 cows/yr) to quantify the effects of environmental conditions during the breeding season on pregnancy rate. Estimated breeding dates were determined by subtracting 283 d from the calving date. Relationships were determined between the proportion of cows bred during the(More)
Data from 3 summer feedlot studies were utilized to determine the environmental factors that influence heat stress in cattle and also to determine wind speed (WSPD; m.s(-1)) and solar radiation (RAD; W.m(-2)) adjustments to the temperature-humidity index (THI). Visual assessments of heat stress, based on panting scores (0 = no panting to 4 = severe(More)
Extreme heat and cold events can create deleterious physiological changes in cattle as they attempt to cope. The genetic background of animals can influence their response to these events. The objective of the current study was to determine the impact of myostatin genotype (MG) on body temperature during periods of heat and cold stress. Two groups of(More)
Numerous models and indices exist that attempt to characterize the effect of environmental factors on the comfort of animals and humans. Heat and cold indices have been utilized to adjust ambient temperature (Ta) for the effects of relative humidity (RH) or wind speed (WS) or both for the purposes of obtaining a "feels-like" or apparent temperature.(More)
Heat stress in feedlot cattle causes reduced performance, and in the most severe cases, death of the animals, thus causing the loss of millions of dollars in revenue to the cattle industry. A study was designed to evaluate dynamics of thermoregulation and feeding activities when feeder cattle were exposed to simulated heat waves, in comparison with repeated(More)
Steers were finished in three different sets of outside lots: 1) pens with overhead shelter on the north side; 2) pens south and southeast of a shelterbelt; and 3) pens with no shelter or windbreak. In trials conducted over a 3-yr period with predominantly British and British x Continental crossbred yearlings, performance improvements due to providing(More)