Date of this Version
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 Yijie Xiong and Andrea Watson
Lincoln, Nebraska, December 2023
Efficiency is of high importance to beef cattle producers to ensure that beef cattle are being raised without unnecessary resource use. Two separate experiments were conducted to evaluate potential strategies to improve efficiency in beef cattle production. A metabolism study was conducted to evaluate digestion parameters of individual Sweet Bran components. The objective was to determine the effects of diet components on nutrient digestion and rumen fermentation parameters. The individual components of Sweet Bran (Corn bran, solvent-extracted germ meal, and corn steep liquor) were included at 40% diet dry matter (DM) in a steam-flaked corn (SFC) based diet. A SFC-based finishing diet was also utilized as a control. Digestibility of OM was greatest for steep and SFC control treatments, while least for germ meal and bran treatments (P = 0.02) when using TiO2 as an external marker. Similarly, OM digestibility was greatest for steep, intermediate for SFC control, and least for germ meal and bran when using ADIA as an internal marker (P < 0.01). Another study was conducted to determine the accuracy of a time-of flight depth camera for predicting body weight of beef heifers. Predicting body weight without the need of a walk-over scale presents opportunities to reduce labor needs and provide accurate body weight estimations more frequently than traditional systems. The objective was to determine the accuracy of using a time-of-flight depth camera as a method to predict shrunk BW of yearling beef heifers. Prediction of shrunk BW using image-extracted dorsal projected volume compared to shrunk BW measured using a walk-over scale produced an R2 = 0.89 and SEM = 3.29 kg. The accuracy of this study is comparable to other research using depth cameras, indicating the potential for application. Further research is needed to identify and improve markers for ruminal digesta flow and to further develop methods of predicting BW of beef cattle.
Advisors: Yijie Xiong and Andrea Watson