Effect Of Source And Level Of Fiber On Feed Intake Digestibility And Digesta Kinetics In Growing Lambs

Author : Clarence Melross Grieve
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (142 download)

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Download or read book Pelleted Rations for Sheep written by Clarence Melross Grieve and published by . This book was released on 1962 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were conducted to study the effects of pelleting of lowland hay rations on rate of gain and efficiency of feed utilization of lambs, rate of rumen fermentation, relative production and proportions of volatile fatty acids in rumen fluid, and cellulose digestion in the rumen. The results of feeding trials with group-fed and individually- fed lambs, showed that pelleted lowland hay rations resulted in marked increases in feed consumption and rate of gain, and improved efficiency of feed utilization, as compared to similar non-pelleted rations. Lowland hay was improved in feeding value as a result of pelleting and gave excellent results in fattening lambs at levels as high as 84 per cent of pelleted rations. Digestibility of dry matter, crude protein and gross energy was lower in rations containing lowland hay than in one composed of alfalfa and barley; digestibility decreased with increasing levels of lowland hay in the ration. The effect of pelleting on digestibility depended on the level of lowland hay in the ration; digestibility was decreased at low levels of lowland hay, but increased at high levels of lowland hay in the ration. An _in vitro study of fermentation rates in rumen samples indicated that rate of fermentation decreased with increasing levels of lowland hay in the ration, but was not affected by pelleting of the rations. Differences in rate of fermentation, as measured by production of gas and acid in manometric fermentations, did not reflect differences noted in feed intake or digestibility when lambs were fed similar pelleted and non-pelleted rations. Concentrations of volatile fatty acids in rumen fluid decreased as the level of lowland hay in the ration was increased. The proportion of acetic acid increased and the proportions of propionic and/or butyric acids decreased with higher levels of lowland hay in the ration. Pelleting of the rations increased the concentrations of volatile fatty acids with rations containing low levels of lowland hay, but had no effect with rations containing high levels of lowland hay; the proportions of volatile fatty acids in rumen fluid were not affected by pelleting of the rations. Concentrations and proportions of volatile fatty acids in rumen samples did not reflect differences in feed intake or rate of gain of lambs. Cellulose digestion in the rumen was measured by an _in vivo technique. A higher percentage of cellulose was digested when lambs were fed non-pelleted lowland hay rations than when lambs were fed an alfalfa- barley ration. Pelleting of a ration containing 60 per cent of lowland hay decreased cellulose digestion, whereas pelleting of a ration containing 90 per cent of lowland hay increased cellulose digestion. The effect of increased energy and available nitrogen on utilization of lowland hay was tested in feeding trials. The addition of stabilized animal fat increased the energy content of pelleted and non- pelleted rations, but did not improve rate of gain or efficiency of feed utilization. Supplementation of rations containing high levels of lowland hay with urea and amino acids did not improve feed intake or rate of gain of lambs.