Our objective was to determine the impact of different habituation protocols on beef cattle behavior, physiology, and temperament in response to human handling. Beef heifers were exposed to three habituation strategies: (1) tactile stimulation (brushing) in the working chute for seven consecutive days (STI; n = 18); (2) passage through the working chute for seven consecutive days (CHU; n = 19) and; (3) no habituation (CON; n = 19). Individual heifer respiratory rate (RR; n/min), internal vaginal temperature (VAGT; °C), and blood cortisol were measured. Further, behavior parameters were observed to generate a behavior score, and heifer interaction with students and their behavioral responses were recorded. Habituation with STI and CHU resulted in improved numerical behavioral scores compared to CON, and greater (p ≤ 0.05) handling latencies. Vaginal temperature was decreased in STI compared to CHU and CONT (p ≤ 0.05). Cortisol concentration did not differ among treatments, but decreased (p ≤ 0.05) from the start of the experiment to 14 days after treatment initiation. Both habituation protocols showed benefits, but heifers that received the positive tactile stimulation in the chute had the greatest behavior improvements. Furthermore, these heifers responded more calmly during student-animal interactions in class, which is beneficial for the students’ and animals’ safety.

The objective of this work was to evaluate the potential benefits of short-duration, high-dose chromium (Cr) supplementation in early postpartum dairy cows during the summer months. Multiparous, early-lactation cows (20.95 ± 0.21 d in milk) were assigned to 1 of 2 treatment groups: (1) control diet (Con; n = 10) or (2) control diet + Cr propionate (CrPro; 12 mg/head per day Cr; n = 12). Measurements of ovarian structures, respiration rates (RR), rectal temperatures (RT), and blood glucose concentrations were recorded every 3 d. Blood was also collected for analysis of plasma progesterone concentrations. Every 6 d, in conjunction with ultrasonography, endometrial cytology samples were collected via cytobrush from each cow to determine the incidences of subclinical endometritis, as determined by polymorphonuclear leukocyte (PMNL)%. No differences were detected in RR, RT, blood glucose, feed intake, milk yield, or change in body weight. The supplementation did, however, improve some reproductive parameters. At cytology sample 6, the PMNL% increased in Con cows, and was greater than the PMNL% in the CrPro group. Chromium consumption did not affect the number or size of most follicles, with the exception being the 6 to 9 mm category where the CrPro group had a greater average diameter and tended to have greater numbers of follicles in this category. While corpus luteum numbers and size did not differ between treatments, the ratio of progesterone to average corpus luteum volume was greater in the CrPro group compared with the Con group. The results from this study indicate that, whereas the short-term, high-dose supplementation strategy did not affect feed intake or milk yield, this Cr supplementation strategy could benefit reproductive performance during periods of stress.

Cattle temperament significantly impacts production traits such as reproduction. The objective of this study was to assess the effects of temperament on pregnancy rates to fixed-timed artificial insemination (TAI) in Bos taurus beef heifers. A total of 297 Angus influenced heifers from 3 different locations were evaluated for temperament based on chute score and exit velocity on the first day of the estrus synchronization protocol (d-9) and classified by temperament type based on temperament score (calm ≤ 3 < excitable). Pregnancy status was determined by transrectal ultrasonography approximately 40 days after TAI. Hair from the tail switch was collected at d-9 and at d0 (TAI) for cumulative cortisol evaluation. A subset of 43 heifers from location 3 had blood samples collected at all handling events and evaluated for cortisol concentrations. Overall, 71% of heifers were classified as calm whereas 29% as excitable. Pregnancy rates to TAI were reduced (P = 0.042) in excitable heifers compared to calm heifers (36% vs. 55%, respectively). Mean concentration of cortisol in the hair was reduced over time (P < 0.001) from d-9 (3.5 ±0.3 pg/mg) to d0 (1.74 ±0.3 pg/mg) in all heifers, regardless of temperament. In addition, excitable heifers had increased circulating concentrations of cortisol when compared to calm heifers in all handling events (P = 0.015). More interestingly, despite of temperament, concentrations of circulating cortisol were reduced as the protocol events progressed, with greater cortisol concentrations on d-9, intermediate on d-3, and lesser on d0 (P = 0.031). Therefore, the present study demonstrates that heifer temperament has negative effects in pregnancy rates to TAI programs. However, according to blood cortisol concentrations, no chronic stress response was detected due to cattle handling for the TAI protocol. In fact, blood cortisol concentration was reduced between the initiation and completion of the protocol, indicating that heifers were acclimated to handing. These results support the adoption of acclimation protocols and proper cattle handling as a strategy to increase fertility of heifers that are exposed to TAI.

The objective of this experiment was to evaluate the impact of a yeast-derived product (Celmanax; Church & Dwight Co., Inc.; Princeton, NJ) supplementation on performance of beef calves during the backgrounding phase. A total of 44 male castrated beef calves [249 ± 31 kg body weight (BW), 296 ±8 days of age], were stratified by BW and randomly assigned to one of two treatments: supplementation of kg^-1calf^-1d of corn gluten feed (Control; n = 22); or supplementation of kg∙animal^-1∙day^-1 of corn gluten feed and 14 g∙animal^-1∙day^-1 (as fed-basis) of a yeast derived product (Treatment, CEL; n = 22). Steer calves received their treatment for 30 days, using an automated feeding system (SmartFeed PRO, C-Lock Inc., Rapid City, SD). Four automated feeders allowed each group to have access to their specific diet, while being managed as a single group during the total duration of the experiment, and daily individual animal supplement intake were recorded. Before the beginning of the experimental period, calves were trained to use the automated feeding system for 30 days. Steer calves also had ad libitum access to a fescue pasture and grass hay. Body weight was measured every 14 days using a livestock scale. At day 30, calves were loaded into a commercial livestock trailer and transported to a feedlot for a total of 6 hours. Feed samples were collected every week, dried to measure dry matter content, and kept for further nutritional composition chemical analyses. Individual daily intake of supplement was similar between treatments (0.82 ± 0.06 and 0.9 ± 0.07 kg/d for CEL and Control, respectively; P = 0.36). Average daily gain (ADG) showed no difference between treatments (0.57 ± 0.05 and 0.61 ± 0.05 kg/d for CEL and Control, respectively; P = 0.59), reaching the same final body weight (256 ± 6.73 kg for CEL and Control; P = 0.98). Body weight loss during transportation (12.6 ± 0.87 kg and 12.4 ± 0.85 kg for CEL and Control, respectively; P = 0.9) was not different between treatments, reaching normal values for that length of transportation. In conclusion, supplementation of a yeast-derived product during 30 days before transportation did not cause any changes in performance of backgrounded beef steer calves.