Animal Science Department


First Advisor

J. Travis Mulliniks

Second Advisor

James C. MacDonald

Third Advisor

Kacie McCarthy

Date of this Version



Ziegler, R.Z. 2020. Impact of cow size and validation of an electronic feeder to optimize resources in beef production systems. M.S. Thesis. University of Nebraska, Lincoln.


A THESIS Presented to The Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Animal Science, Under the Supervision of Professors J. Travis Mulliniks & James C. MacDonald. Lincoln Nebraska: May, 2020

Copyright 2020 Robert L. Ziegler


Optimizing beef production systems is critical in the longevity of an enterprise. In a time of rapid change and innovation, there are increasingly more opportunities to improve efficiency of livestock production by taking advantage of new technologies. Furthermore, production environments vary drastically in all segments of the beef industry, which influence feed resource availability. Therefore, it is critical to realize the cow type that excels in a given production environment according to management objectives. To gain a better understanding of the optimal cow type in the Nebraska Sandhills, a retrospective analysis was conducted to evaluate increasing cow body weight (BW) on cow performance, steer progeny performance, and heifer progeny performance. As cow BW increased, the ability to maintain BW and body condition score (BCS) from pre-calving to weaning increased. Pregnancy rates were improved in larger-sized cows. As cow BW increased, steer progeny had increased BW at weaning, at feedlot entry, and greater hot carcass weights with minimal impact on carcass quality. Increasing cow BW also increased heifer progeny weaning weights, post-weaning BW, pre-breeding BW and BW pre-calving; however, heifer progeny reproductive performance was not influenced by dam BW. In a hypothetical scenario using regression data, smaller-sized cow herds may have increase total production output of calf BW at weaning and cull cow BW. Innovative electronic feeding systems may provide an advantage to monitor cattle and deliver supplement more consistently increasing beef production efficiency. Two validation studies were conducted to quantify the acclimation period associated with the introduction of an electronic feeder to naïve cattle. In experiment one, (13%) of the cows did not use the feeder over a 23 d test period. In experiment 2, (7%) of heifers did not use the feeder over a 14 d period. In both experiments, as ambient temperature decreased, supplement intake tended to decrease. Cows most frequently visited the feeder early in the morning after sunrise. A better understanding of the cow type and supplement delivery technology that optimizes resources and animal behavior could improve efficiency in livestock production.

Advisor: J. Travis Mulliniks and James C. MacDonald