Research: Effect of Shade on Finishing Cattle in a Commercial Feedlot

For the research feature this month, we have included an abstract from Phi Zeta Day held on Tuesday, March 4, 2014. This presentation was made by BCI graduate student, Jacob Hagenmaier. The purpose of the K-State Phi Zeta Research Day is to promote research pertaining to the welfare and diseases of animals through the graduate student poster and oral presentations. These presentations are scored and the top three presentations in several areas recognized with awards. Watch for additional abstracts to be featured in upcoming newsletters!

Effect of Shade on Performance, Carcass Quality, and Welfare in Finishing Cattle in a Commercial Feedlot.

Author(s): Jacob A. Hagenmaier; Chris

D. Reinhardt, PhD.; Steven J. Bartle, PhD.;

Daniel U. Thomson, DVM, PhD (Lab leader).Jacob Hagenmaier

Feedlot cattle (n=1,395; BW=568 Å} 43 kg) were used to measure the effects of shade on performance, carcass quality, and welfare of finishing cattle fed a beta adrenergic agonist during the summer in a Kansas commercial feedlot. Cattle were randomly assigned to receive either: 1) No Shade (control) or 2) Shade. Seven groups of predominately black steers and heifers

(4 and 3, respectively, n=7 replications per treatment) were randomly divided and allocated to shaded and non‐shaded pens. Pen served as the experimental unit.

Duration of trial (Mean=38.4 d, range=26 to 53 d) and shade area per animal within shaded pens (Mean=1.46 m2/animal, range=1.13 m2 to 1.78 m2/animal) varied among replicates.

No difference in ADG was observed between shaded and nonshaded treatments (1.94 vs 1.97 Å} 0.17 kg; P=0.27). Shaded cattle had greater DMI than non‐shaded cattle (10.77 vs. 10.52

Å} 0.78 kg; P=0.01). Shaded cattle tended to be less feed efficient

(5.64 vs. 5.37 Å} 0.25 kg; P=0.09). No difference in hot carcass weight was noted between treatments (404 vs. 402 Å} 30 kg;

P=0.30). Percentage of cattle grading choice or better tended to be greater for the shade treatment (72 vs. 67 Å} 8%; P=0.12).

Shade‐treatment cattle had a greater dressing percentage than

nonshaded cattle (65.4 vs. 65.05 Å} 0.3%; P=0.01). Shade reduced the number of cattle open‐mouth panting on observation days (P<0.001). Providing shade for finishing cattle during the final

26 to 53 d on feed in the summer resulted in improved animal comfort, increased DMI and dressing percentage, and tended to increase quality grade; however, non‐shaded cattle tended to be more feed efficient and no difference in daily gain was observed between treatments.

Phi Zeta Day Awards

Congratulations to the BCI Graduate Students who received awards in recognition of their work on Phi Zeta Day!

Clinical Science/ Applied Research Food Animal Presentations:

2nd Place: Aaron Schaffer

Other special awards

Mahlon Vorhies Production Animal Award – Shane Terrell

About Phi Zeta

Phi Zeta is the only honor society of veterinary medicine in the United States The purpose of Phi Zeta is to promote, acknowledge, and reward scholarship in the profession of veterinary medicine. Third-year students ranking in the top

10% of the class and fourth-year students ranking in the top 25% of the class are invited to become members. Honorary membership may also be bestowed upon interns, residents, faculty and non-veterinary field related persons who have made significant contributions to veterinary medicine.