Rumen Fementation and In Vivo and In Vitro Digestibility of All-in-One Dairy Rations

Abstract

A series of 3 trials using fistulated steers and artificial rumens studied the factors influencing crude fiber and cellulose digestion and rumen fermentation of All-in-One rations. In Trial 1, rumen fluid from steers fed only alfalfa pellets or a mixture of 60% pellets and 40% of either beet pulp or flaked corn was used to measure cellulose disappearance in artificial rumens. The pellets alone produced the least cellulose disappearance, with corn being intermediate and beet pulp highest. In Trial 2, a complete ration low in starch and high in structural carbohydrates was fed as meal, cubes, or pellets. Only pelleting increased (P = < .01) molar concentration of total and individual volatile fatty acids. Cottonseed hulls, rice by-product (feed) and Coastal bermudagrass hay were compared in Trial 3 where they provided 50% of the total crude fiber. The 3 sources of fiber did not produce significantly different patterns of rumen fermentation. The rations in Trials 2 and 3 produced large concentrations of total and individual volatile fatty acids, suggesting a possible factor in several problems asociated with such rations. © 1970, American Dairy Science Association. All rights reserved.