Programmed Feed Intake of High Energy Diets Influences Digestibility and Maintenance Requirements of Beef Cattle

Four studies were conducted to determine the effects of programmed feed intake of high-energy diets and how it influences digestibility and maintenance requirements of beef cattle. In the first experiment, 32 cows were used in a lactation study to determine the effects of program fed soyhulls on cow lactation and performance. Program feeding of corn or soyhull based diets outperformed (P < 0.05), higher weight gains, ADG, and BCS, the ad libitum forage diet. No differences were observed for calf performance, or lactation parameters. In the cull cow study, programmed feeding increased diet digestibility (P 0.05) on carcass or visceral organ parameters. In the second experiment, feeding a programmed intake of high-energy diet will allow heifers to exhibit estrus at an adequate age to first calve at 24 months of age. A minimum of 97.5% of the heifers fed on a program fed regime were cyclic for at least one month prior to artificial insemination (P < 0.05). In the third experiment, a metabolism study was used to determine the digestibility estimates of ad libitum and program fed corn and soyhull diets as well as a forage diet. Feeding a soyhull based diet increased acetate and butyrate proportions in the rumen in comparison to the corn based diet (P < 0.05). Programmed feeding of either the corn or soyhull based diet increased rumen pH (P < 0.05). An increase of total nitrogen flow to the small intestine was observed (P < 0.05) for the ad libitum and program fed soyhull based diets. Liquid dilution rates were reduced with both the program fed corn and soyhull diets. A tendency (P < 0.20) of increased ruminal NDF digestibility was observed for program fed soyhull diet when compared to the program fed corn diet. In the fourth experiment, steers were serially harvested to determine the effects of early weaning and restricted intake on gastrointestinal tract and visceral organ mass. Programmed feeding of early-weaned steers was not effective for improving carcass or performance parameters (P > 0.05).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Animal Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Wells, Robert Sean

Contributors dc:contributor

• Faulkner, Dan B.

• Agriculture, Animal Culture and Nutrition

Language dc:language

eng

Identifier

(MiAaPQ)AAI3131051

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83570