Related Experiment Video
Updated: May 27, 2026

Protocol for Assessing the Relative Effects of Environment and Genetics on Antler and Body Growth for a Long-lived Cervid
Published on: August 8, 2017
Effect of a nutritional reconditioning program for thin dairy cattle on body weight, carcass quality, and fecal
Gabriele U Maier1, Bruce R Hoar, Carolyn L Stull
1Department of Medicine, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
Objective:
To assess changes in body weight, carcass quality, and fecal pathogen shedding in cull dairy cows fed a high-energy ration for 28 or 56 days prior to slaughter.
Design:
Randomized clinical trial.
Animals:
31 adult Holstein dairy cows.
Procedures:
Cows were randomly assigned to a control (immediate slaughter) group or a 28-day or 56-day feeding group. Cows in the feeding groups received a high-energy feed and were weighed every 7 days. Carcasses were evaluated by USDA employees. Fecal and blood samples were collected at the start and end of the feeding periods.
Results:
Body condition score and adjusted preliminary yield grade were significantly increased in both feeding groups, compared with values for the control group; body weight, hot carcass weight, dressing percentage, and ribeye area were significantly increased after 56 days, but not after 28 days, compared with values for the control group. Average daily gain and marbling score were significantly lower after feeding for 28 days versus after 56 days. Prevalence of Escherichia coli O157:H7 shedding in feces decreased from 14% to 5.6%, but this difference was not significant. Cows seropositive for antibodies against bovine leukemia virus that had signs of lymphoma and lame cows had a low average daily gain. Net loss was $71.32/cow and $112.80/cow for the 28-day and 56-day feeding groups, respectively.
Conclusions And Clinical Relevance:
Feeding market dairy cows improved body condition and carcass quality. Cows seropositive for antibodies against bovine leukemia virus that have signs of lymphoma and lame cows might be poor candidates for reconditioning.
