Further Observations on the Effect of Physical Preparation of the Ration on Volatile Fatty Acid Production

The nutritive value of ground and pelleted barley straw. I. Ground and pelleted v. long straw for growing Ayrshire heifers

“…Grinding generally reduces the digestibility of a roughage (Forbes, Fries & Braman, 1925;Mead & Goss, 1935;Weir et al 1959;Heaney, Pigden, Minson & Pritchard, 1959). The reduction in digestibility mainly affects the crude fibre or cellulose fractions (Alexander & Hentges, 1962;Woods & Rhodes, 1962;Campling, Freer & Balch, 1963;Reynolds & Lindahl, 1960), and appears to be related to increased rate of passage through the gut, allowing less time for microbial digestion of fibrous material in the rumen (Blaxter, Graham & Wainman 1956;King, O'Dell, Cooke & Moore, 1963). Campling et al (1963) reported similar retention times for ad lib.…”

“…Rations containing ground and pelleted roughage reduce rumen pH compared with the same materials fed in the long state, due in part at least to reduced saliva flow, and there is often a reduction in the proportion of acetic acid and increase in the proportions of propionic and/or butyric acids in the rumen liquor (Balch & Rowland, 1957;Wright, Pope & Phillips, 1963;Alexander & Hentges, 1962;Rhodes & Woods, 1962;Woods & Luther, 1962).…”

“…Pelleting lucerne meal or regrinding the pellets did not affect digestibility (Lindahl & Reynolds, 1959;Church, McArthur & Fox, 1961), nor did pelleting a finely ground hay (Wright et al 1963). However, Rhodes & Woods (1962) claimed, that pelleting a finely ground hay reduced the proportion of acetate to propionate in rumen liquor, but obtained a similar effect when the hay was fed unground. Woods & Luther (1962) reported a similar effect of pelleting and also reported that increased fineness of grinding increased the ratio acetate:propionate when the roughage was fed with concentrate, but not when fed alone.…”

Estimation of Stoichiometric Parameters for Rumen Fermentation of Roughage and Concentrate Diets

“…The data represented results on 137 animals from 20 studies (Stewart et al, 1958;Leng andLeonard, 1965;Gray et al, 1967;Weston, 1967, 1969;Hogan, 1967, 1971;Corbett et al, 1969;Beever et al, 1971;Thomson et al, 1972;Chaturvedi et al., 1973 a, b;Punj et al, 1974;Egan et al, 1975;Harrison et al, 1975;Walker et al, 1975;Besecke and Mohme, ~976;.Van Der Walt and Briel, 1976;Hume, 1977;Van Der Walt, 1977). The second group represented data on 48, mostly concentrate diets fed to 374 experimental animals and reported in 18 papers (Balch and Rowland, 1957;Woods and Luther, 1962;Oltjen and Davis, 1965;Oltjen et al, 1965;Thompson et al, 1965;Clanton and Woods, 1966;Weiss et al, 1967;Sutton, 1969;Sutton and Johnson, 1969;Franks et al, 1972;McCormick, 1972, 1975;De Vuyst et al, 1974;Stanley et al, 1975;White et al, 1975;Besecke and Mohme, 1976;Barry et al, 1977;Oshio et al, 1977).…”

Effect of sodium bicarbonate supplementation on feed intake, digestibility, digesta kinetics, nitrogen balance and ruminal fermentation in young fattening lambs

“…It is noteworthy that these low ratios (<1.5) fell into the range (from 0.9 to 4) previously reported by other authors (Woods and Luther, 1962). A negative effect of sodium bicarbonate on propionate production would have been very advantageous in fattening lambs because when in excess, propionate might be a precursor for the synthesis of oddnumbered and methyl branched chain fatty acids, whose proportions are high in soft adipose tissues (Normand et al, 2001).…”