The Influence of Casein upon Roughage Digestion in Cattle with Rumen Bacteriological Studies

The effect of quality and quantity of carbohydrate and protein in the ration of the sheep on the digestibility of cellulose and other constituents of the ration, with a note on the effect of adding vitamins of the B-complex on the digestibility and retention of the nutrients of a hay ration

“…This result differs from that reported by previous workers (Hoflund et al 1948;Louw et al 1948;Burroughs, Gall, Gerlaugh & Bethke, 1950). The reason for this discrepancy may be that the numbers and activity of the cellulose-digesting organisms is independent of supplementary feed nitrogen when their substrate contains about 1 % nitrogen as in this series of trials, but not when it contains only about 0-3 % as in the veldt hay and maize stover substrates used by the other workers.…”

“…Previously it has been shown that the digestibility of crude fibre, a fraction containing part of the (Norman-Jenkins) cellulose, is depressed by the addition of maize starch to the ration (Zuntz, 1891;Kuhn, 1894;Kellner, 1907;Zuntz, 1913;Markoff, 1911Markoff, , 1913Ewing & Wells, 1915;Armsby & Fries, 1918;Swift et al 1947). It has also been shown that the dry matter of the roughage portion of a mixed ration is depressed under similar circumstances (Burroughs et al 19496;Burroughs, Gall, Gerlaugh & Bethke, 1950).…”

“…The simultaneous addition of protein and maize starch does not depress the digestibility of cellulose as much as maize starch alone (Hoflund, Quin & Clark, 1948;Louw et al 1948;Burroughs, Gall, Gerlaugh & Bethke, 1950). Recent work in South Africa suggests that the addition of nitrate with molasses may effect an improvement in the digestibility by the ruminant of the fibre of veldt hay (Ann.…”

The inter-relationships of individual proteins and carbohydrates during fermentation in the rumen of the sheep. I. The fermentation of casein in the presence of starch or other carbohydrate materials

“…There are numerous observations of this type measuring the effects of various supplements. Thus Burroughs et al (1950) showed that under the conditions of their experiments starch supplements reduced the roughage digestion and casein appeared to increase it; the effect of casein was, however, found only when starch was also present. Head (1953) also showed that starch depressed and protein had no influence on cellulose digestion in the sheep: he concluded that provided a roughage had a N-content of above 1 %, cellulose digestion was independent of supplementary feed-N.…”

“…Wicke & Weiske, 1896;Fontenot, Gallup & Nelson, 1955), and it is often reported that as the protein intake is increased there is a more rapid attack upon the fibrous components of the ration (e.g. Burroughs, Gall, Gerlaugh & Bethke, 1950). The value of increasing the protein intake from the low level may be related to the requirement for branch-chained volatile fatty acids in cellulose digestion (Bentley, Lehmkuhl, Johnson, Hershberger & Moxon, 1954;Bryant & Doetsch, 1954); these acids can be obtained during the breakdown of protein (Shazly, 1952;Annison, 1954).…”