Apparent Ruminal Digestibility of Forage Soybean Silage Utilized in Developing Heifer Diets

Author

Karra Beth Herron, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2015

Degree Name

Master of Science

Department

Animal Science

First Advisor

Atkinson, Rebecca

Abstract

Apparent digestibility of forage soybean silage was evaluated utilizing a dual continuous flow apparatus in a Latin Square design. The fermenters were inoculated with a mixture of rumen fluid from two ruminally cannulated Angus cows. Fermenters were randomly assigned to one of the following treatments: 1) 76.1% alfalfa silage, 16.1% corn stover, 6.7% dry distiller’s grains (CON); 2) 75.1% soybean silage, 6.5% corn stover, 17.3 % soyhulls (SB); 3) 63.5% soybean pearl millet mixed silage, 15.2% corn stover, 20.2 % soyhulls (SBPM);4) 61.4 % rye grass, 14.8% corn stover, 4.8% dried distiller’s grains, 18.0 % soyhulls (RYE). All diets contained 1.1 % Purdue Heifer developer and were balanced to meet or exceed NRC requirements for a developing heifer and to contain 13.9% crude protein. Treatment had no effect (P ≥ 0.43) on the apparent ruminal digestibility of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF) or crude protein (CP). The SB forage source had the greatest (P = 0.03) fat digestibility compared to SBPM but similar to CON and RYE. Data suggests that the digestibility of forage soybean silage is similar to the digestibility of alfalfa silage. Additionally, if a producer is interested in planting a mixture of forage soybeans and pearl millet silage it too is similar in digestibility when compared to forage soybean alone and alfalfa silage.