Digestibility of by-product feeds by sheep

Graduation date: 1978Two digestibility trials using sheep were conducted to determine\ud the digestibility coefficients of a commercially processed NaOH treated\ud annual ryegrass straw cube. Comparisons were made with loose, chopped\ud ryegrass straw and a ryegrass straw cube processed with molasses as a\ud binder.\ud The NaOH cubed straw was produced by spraying a solution of 30%\ud NaOH evenly over the straw and processing through a cuber. The resulting product averages 4% NaOH by weight. This treatment resulted\ud in significant (P < .05) increase in the digestibility of dry matter,\ud acid detergent fiber, and nitrogen-free-extract when calculated by\ud difference using chopped alfalfa. A trend toward increased digestible\ud protein and digestible energy was shown. Cubing with molasses did not\ud improve (P < .05) the digestibility of ryegrass straw when calculated\ud by difference. Digestibility of loose ryegrass straw was significantly\ud (P < .05) improved by the NaOH treatment with regard to dry matter,\ud crude protein, and acid detergent fiber when calculated "directly"\ud using urea and molasses.\ud The TDN (Total Digestible Nutrients) for the NaOH treated rye\ud grass straw cubes was 45.3% when calculated by difference and 44.4% when figured "directly". The TON values for the molasses cubes by\ud difference, plain straw by difference and plain straw "directly" were\ud 39.7%, 41.3%, and 44.7% respectively.\ud The conclusion was made that this type of Na0H treatment of rye\ud grass straw resulted in significant improvement in its digestibility\ud when fed to sheep.\ud A third digestibility trial was run to determine digestibility and\ud nutrient composition of a dried bakery product (DBP). This product is\ud produced from nonsaleable bakery products which are mixed, dried, and\ud ground. DBP is primarily fed to dairy cows when used in the Northwest.\ud Digestibility was calculated by difference using "typical" dairy ration\ud components. Nutrient composition (%) of the DBP for crude protein (CP),\ud ether extract (EE), ash, acid detergent fiber (ADF), nitrogenfree\ud extract (NFE), organic matter (OG), calcium, and phosphorous were, respectively, 10.4, 8.5, 3.8, 1.8, 75.5, 96.2, .036, and .088. The gross\ud energy was 4.29 Kcal/g. The digestibility of these components when fed\ud at 20% and 40% of the diet, respectively, was (%) DM, 94.5, 93.4; CP,\ud 82.4, 80.1; EE, 84.7, 84.4; OG, 64.5, 88.9; ADF, 99.7, 89.7; NFE, 97.7,\ud 94.3; and GE, 95.8, 90.6. The digestibility coefficients were not sig\ud nificantly (P < .05) different when fed at the two levels, but a trend\ud was noted of lowered digestibility when fed at the higher level. TDN\ud values at the 20% and 40% levels were 93.1% and 88.0%, respectively.\ud It was apparent that the possibility exists that the DBP could be\ud increasing the digestibility of other ration components