Protein Supplementation and Grazing Behavior for Cows on Differing Late-Season Rangeland Grazing Systems.

The objective was to determine if low- or high-residual feed intake (LRFI or HRFI, = 24 for each) Hereford × Angus cows on continuously or rotationally grazed rangeland altered their grazing behavior when provided a protein supplement in late autumn. Treatments included continuously grazed, control (CCON, = 12); continuously grazed, supplemented (CTRT, = 12); rotationally grazed, control (RCON, = 12); and rotationally grazed, supplemented pastures (RTRT, = 12). Cows in each treatment had grazing time (GT), resting time (RT), and walking time (WLK) measured for 2 years with accelerometers.

Variation in type two taste receptor genes is associated with bitter tasting phenylthiocarbamide consumption in mature Targhee and Rambouillet rams.

Bitter taste perception in sheep can lead to avoidance of specific types of forage, such as sagebrush, which is present on many rangeland grazing systems in the Intermountain West. In humans, bitter taste perception is influenced by variation in several TAS2R genes, including more extensively studied and . We hypothesize that variation in taste receptor genes in sheep is associated with bitter taste.

Grazing behavior and production for lactating cows differing in residual feed intake while grazing spring and summer rangeland.

The objectives were to determine if previously classified, efficient (LRFI, low-residual-feed intake, = 12 × 2 yr) vs. inefficient (HRFI, high-residual-feed intake, = 12 × 2 yr) lactating 2-yr-old Hereford × Angus cows differed in grazing behavior, body weight (BW), body condition score (BCS), and calf weaning weight while grazing rugged rangeland pastures. Cows were fitted with grazing halters containing both an accelerometer and a global positioning system (GPS) data logger during June 14 to July 4, 2016, August 2 to 25, 2016, May 23 to June 12, 2017, and August 5 to 28, 2017.

Avoidance of phenylthiocarbamide in mature Targhee and Rambouillet rams.

Shrub encroachment on grasslands is a worldwide issue and sheep are a potential tool for mitigating shrub encroachment. Many shrubs, however, contain bitter-tasting compounds that may deter grazers. Cattle and sheep commonly graze rangelands, but of the two, sheep have a greater tolerance for bitter compounds and would be expected to consume more bitter-tasting vegetation.

Intake behaviors of yearling steers grazing irrigated pasture and receiving either a free-choice salt-based mineral or a low-moisture molasses-based tub mineral.

Mineral intake in grazing cattle is highly variable and research evaluating behavioral aspects of intake are minimal. Development of the GrowSafe System to monitor feed intake allows researchers to record individual feeding behaviors of cattle 24 h per day. In the current experiment conducted during June and July, the GrowSafe System was utilized to evaluate intake behaviors of grazing steers during a short-term free-choice supplementation of either salt-based loose minerals (; = 24; 408 ± 57 kg) or low-moisture molasses-based tub minerals (; = 24; 396 ± 64 kg).

Effect of increased inclusion of dried distillers grain supplement on adaptation, intake, digestibility, and rumen parameters in steers consuming bermudagrass round bale silage.

Eight ruminally cannulated beef steers were used to evaluate forage intake and physiological response during adaptation to a diet consisting of bermudagrass round bale silage (RBS) and dried distillers grains (DDG) and in a second experiment the effect of level of DDG supplementation on RBS forage intake, digestibility, and rumen parameters. The adaptation experiment was designed to simulate a 14-d step-up process. Initially steers received ad libitum RBS, on d 4 steers were offered 1.

Select Synch and Co-Synch protocols using a CIDR yield similar pregnancy rates after a fixed-time insemination in suckled Bos indicus × Bos taurus cows.

Primiparous and multiparous suckled Bos indicus × Bos taurus cows were used to compare a Select Synch + controlled internal drug release (CIDR) and timed artificial insemination (AI) protocol (SSC) to a modified CO-Synch + CIDR protocol (COS). Five separate groups of cows were utilized (n = 659) and within a group, cows were allotted to two treatments on the basis of body condition score (BCS) taken 10 days before and days postpartum at CIDR insertion (Day 0). Blood samples were collected on Day -10 and 0 for assessment of circulating concentrations of progesterone to determine estrous cycling status.

Response to GnRH on day 6 of the estrous cycle is diminished as the percentage of Bos indicus breeding increases in Angus, Brangus, and Brahman x Angus heifers.

Angus (n=6), Brangus (5/8 Angus x 3/8 Brahman, n=6), and Brahman x Angus (3/8 Angus x 5/8 Brahman, n=6) heifers exhibiting estrous cycles at regular intervals were used to determine if the percentage of Bos indicus breeding influenced the secretory patterns of LH in response to a GnRH treatment on Day 6 of the estrous cycle. Heifers were pre-synchronized with a two-injection PGF(2 alpha) protocol (25 mg i.m.

Efficacy of either a single or split treatment of PGF2alpha after a 14 day melengestrol acetate treatment to synchronize estrus and induce luteolysis in Bos indicus x Bos taurus heifers.

Two experiments evaluated a modified delivery of prostaglandin F2alpha (PGF2alpha) after a melengestrol acetate (MGA) treatment in Angus and Bos indicus x Bos taurus (BI) heifers. Experiment 1 was replicated three times with yearling BI heifers (n = 695). Heifers received MGA (0.

Environmental, genetic and social factors affecting the expression of estrus in beef cows.

Genetic, social and environmental factors affecting behavioral estrus were evaluated in Angus (n = 10), Brahman (n = 10) and Senepol (n = 10) cows during a PGF2alpha synchronized estrus and subsequent spontaneous estrus. Cows were equally stratified by breed to two groups of 15. Both groups were pre-synchronized with a modified two-injection PGF2alpha protocol.