Utilization of volatile fatty acids and glucose for protein deposition in lambs

Abstract

I . Glucose, and acetic, propionic and butyric acids, the major energy sources available to ruminants, have been comparatively evaluated as energy sources for growth in lambs. The energy sources wcrc administered intravenously at 2.092 and 2 . j 10 MJ metabolizable energy per 24 h for periods of 9-12 d. Nitrogen was given in excess of requirement so that growth rate was limited by energy, as indicated by the increased N retention after intravenous administration of energy.2. The N-balance results from the trials showed that propionic acid promoted a significantly ( P < 0.01) higher N retention than acetic acid. In some of the experiments there were no significant difYerences between propionic and butyric acids, and in others, no significant differences between acetic and butyric acids. Compared with isoenergetic glucose infusion, all volatile fatty acids were less efficiently utilized than glucose. The mean values for N balznce (gjd) were 2.37 during control infusion, 6.53, 571, 5.48 and 4 5 9 during glucose, propionate, butyrate and acetate infusions, respectively.3. All energy sources reduced the faecal N excretion significantly. The greatest reduction was observed during butyrate treatment. The mean values for faccal N excretion (gjd) w-ere 4.24 €or control, 4.00 for acetate, 3.89 for propionate, 3.83 for glucose, and 3.76 for butyrate infusion. The reduced faecal N excretion after hutyrate infusion partly accounts for the increased N retention with that treatment.

Effect of Dehydrated Pig Faeces in the Diet on Microbial Protein Synthesis and Fermentation Balance in the Rumen of Holstein Steers

“…5 , t h e efficiency of energy utilization decreases (Urskov cf a / . , 1968) as well as N retention (Eskeland et al, 1973); NGR was always above 5.0 across treatments. In the present work, yielding ATP (,A4TP) did not show any effect of t r e a t m e n t ; h o w e v e r , it w a s possible t o appreciate a numerical trend which indicates a linear increment with the level of inclusion of DPF (Table 3).…”

Intravenous energy infusion in lambs: effects on nitrogen retentin, plasma free amino acids and plasma urea nitrogen

“…The specific effects of the intravenously administered energy sources upon excretion of urinary N and faecal N and on N balance found in earlier experiments are discussed elsewhere (Eskeland et al 1973). The N balance results of the two experiments described here will be used to relate these values to plasma concentrations of free amino acids and PUN.…”

The effect of level of feeding on the carbohydrate of duodenal digesta in cattle given a high grain diet

“…There was, however, no increase during the hour after the second feeding for an unknown reason. A comparison of hours 1, 3, 5 and 7, at the beginning of which the steers were fed, with hours 2, 4, 6 and 8 when the animals were not fed, showed a significant influence (P>0.05) The average dry matter content of 4.80 and 5.80 for the low and high levels of intake, respectively, was in close agreement with valsas obtained for sheep (Phillipson and Ash, 1965;Thompson and Lamming, 1972;Thompson, 1973) (Armstrong, Blaxter and Graham, 1960;Armstrong and Blaxter, 1957;Eskeland et al, 1973;Black, 1971). 2.…”