Rates of production of volatile fatty acids in the rumen. V. Evaluation of fodders in terms of volatile fatty acid produced in the rumen of the sheep

Abstract

l(a). Volatile fatty acid (VFA) production (moles/12 hr) by two sheep fed at 2-hourly intervals on a constant ration containing equal parts of wheaten hay and lucerne hay, showed no significant difference between the sheep or between day-time and night-time values. The precision with which production could be measured over a series of 12-hr periods is given. The quantities of VFA produced in the rumen on successive days varied considerably; the extent of this variation was similar to that occurring in the quantities of faeces passed. (b) Production remained much the same whether the sheep were fed at intervals of 1, 2, or 12 hr. (c) The energy of the VFA produced in the rumen was equivalent to about 54% of the digestible energy of the diet. 2. Similar amounts of VFA were produced from two different mixtures of wheaten hay and lucerne hay, and from lucerne hay alone. 3. A modification in the procedure for measuring VFA production was tested and found to be satisfactory. The necessary apparatus could be readily carried on the back of a freely moving sheep.

Parameters of Rumen Fermentation in a Continuously Fed Sheep: Evidence of a Microbial Rumination Pool

“…VFA and ammonia-N concentrations are in good agreement with the estimates in the literature (5,8,23). The zero-time rates of VFA production are similar to the results obtained with a radiotracer technique in sheep fed continuously with approximately the same daily amounts of feed (6,8,23). The ammonia production estimates are within the ranges reported by Pilgrim et al (23).…”

Studies on forage cell walls: 5. Alkali-treated lucerne

“…Group mean values of VFA production/100 g DOMI were not statistically different due to within-treatment variations. However, the molar proportions of individual acids conformed to a normal pattern (Weller et al 1967;Gray et al 1967) with evidence of a trend towards more propionic and valeric acids in the 6K group. Microscopic examination of rumen liquors sampled 4 h after feeding revealed a significant increase in the pro-…”

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

“…The first set consisted of information on 60 over 50% roughage 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).…”