Ruminal and Post-ruminal Digestion of Alfalfa Fed as Pellets or Long Hay

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Abstract
The extent of ruminal and total digestion of the carbohydrate portion of long alfalfa and dehydrated, pelleted alfalfa was com- pared using the lignin-ratio method with four rumen fistulated steers. The apparent digestibility of the fibrous portion (crude fiber, acid detergent fiber, cellulose, and holocellulose) of pelleted al- falfa was only about 70% that observed for long hay. The apparent digestibility of the nitrogen-free extract did not differ significantly. The extent of the nitrogen- free extract digested in the reticulo-rumen was lower on the pelleted alfalfa ration than on the long alfalfa ration. While feeding pelleted alfalfa, less than 60% of the digestible fibrous portion was di- gested in the reticulo-rumen; whereas, more than 90% was digested in the reticulo- rumen when long alfalfa was fed. The proportion of ruminal acetic acid was lower, and the propionic and butyric acids were higher when feeding pellets com- pared to hay. Total volatile fatty acids and ruminal fill were depressed by the pellet ration. Pelleting or fine grinding of forages increases