Feeding Strategies for Beef x Dairy Cattle

Abstract

The overall objective of this thesis was to investigate the effects of nutrition on growth, development, meat quality, and sensory characteristics of beef x dairy crossbred cattle. Large advances in dairy cattle reproduction have led to an influx of dairy replacement heifers on dairy farms and the subsequent drop in the price producers receive for these animals. Producers have turned to breeding their lowest genetic potential cows to beef breeds to increase the value of the resulting calf when it is no longer needed in the herd. Due to the increasing popularity of these crossbred animals and the minimal information available on how to feed them, this thesis seeks to encompass a few main questions that producers, packers, and consumers have about this topic. Chapter one reviews literature pertaining to the topics to be investigated further in the thesis, including feed efficiency, performance of dairy cattle raised in feedlots, carcass quality of crossbred cattle and a comparison of meat sensory characteristics between dairy and beef animals. With a stark difference in feeding programs on dairy and beef operations, the review explores which practices have the greatest effect on growth. When introducing finishing diets to Holstein-influenced cattle, feedlots can run into issues with increased days on feed and liver abscess prevalence, among other carcass and meat quality issues. We explore the idea that diet plays a large role in these issues. Chapter two discusses how milk replacer feeding program and weight at onset of the finishing diet impacts growth, development, and carcass quality in Angus x Holstein steers and heifers. We investigated how length of the liquid feeding program and differences in milk replacer protein and fat levels affect calf gains, muscle and skeletal development, and gain efficiency in calves under 7 weeks of age. This was followed by initiating the finishing diet at differing weights with half of the cattle receiving the finishing diet starting at 226 kg bodyweight, and the other half starting the at 317 kg bodyweight in an effort to shorten days on feed without compromising carcass quality. Overall, there was no significant effect on BW, ADG or body measurements based on MR feeding regimen. At harvest, cattle from both the LIGHT and MEDIUM finishing diets saw favorable quality and yield grade characteristics that would qualify the carcasses for branded beef programs. This was done without significant liver abscess prevalence. However, differences in BW were seen between male and female calves. In the experiment detailed in chapter three, we further follow the cattle from studies conducted in chapter two and evaluate the effects of feeding treatment and calf sex on meat quality and sensory characteristics. With the increased production of these crossbred animals from the dairy industry, it is up to the industry to ensure that quality and sensory characteristics are not compromised. Color and tenderness are perhaps of most interest to the average consumer, though shape of the steak also has an effect on willingness to purchase and the price consumers are willing to pay. We evaluated both cooked and raw samples of ribeye and loin steak from crossbred animals, comparing them to samples from Holstein and Angus cattle. Overall, we found some differences in meat quality between feeding regimens and calf sex. Feeding regimen and calf sex had no significant effects on fresh meat color across days 1, 3 and 7 post-fabrication. The LIGHT feeding regimen had significantly more fat in the muscle when evaluated for proximate composition. Male calves also tended to have bigger carcasses, with significantly larger rib primals.