Date of Award
Master of Science
George Merriman, W. R. Backus
The purpose of this experiment was to determine the effects on feedlot performance and carcass characteristics of slaughtet heifers when grown and fattened on a urea-limestone treated corn silage ration in which the average daily crude protein intake per head was 0.8, 0.9, and 1.0 kg. (1.7-1.8, 1.9-2.0, and 2.1-2.2 lbs.) and to test for any difference between cottonseed meal and urea as an additional supple-mental protein source. In addition to corn silage ad libitum, each animal received 2.7 kg. (6.0 lbs.) of concentrate per day during a 140 and 110 day roughage phase for Trial I and II, respectively, to provide three different levels of protein. The concentrate portion of ration 1 consisted of corn only and provided 0.8 kg. (1.7-1.8 lbs.) of crude protein per head per day. Concentrate in rations 2 and 4 consisted of corn plus cottonseed meal and provided 0.9 kg. and 1.0 kg. (1.9-2.0 and 2.1-2.2 lbs.) of crude protein per head per day, respectively. Rations 3 and 5 consisted of corn plus urea and provided 0.9 kg. and 1.0 kg. (1.9-2.0 and 2.1-2.2 lbs.) of crude protein per head per day, respectively. The heifers were full fed a concentrate ration of eight parts cracked shelled corn to one part cottonseed meal following the roughage phase. Animals were finished to a predetermined, ultrasonically measured fat thickness. There were a few significant (P < 1.05) differences in feedlot performance and carcass characteristics between treatments. However, the significances were not found in traits of economic importance in either trial.
Kaufman, Dwight Allan, "Effect of different sources and levels of protein on the performance of feeder heifers. " Master's Thesis, University of Tennessee, 1974.