A note on the utilization of the energy of the short-chain fatty acids in the fattening sheep

Abstract

SUMMARY: Complete C, N and energy balances were carried out on two mature sheep receiving a basal diet of pelleted hay plus continuous intraruminal infusions of either water or 400 kcal/day of propionic acid, butyric acid or a mixture of acetic acid and sodium acetate, for periods of 1 to 5 weeks. The efficiency of utilization for maintenance plus fattening of the basal diet and the basal diet supplemented with acetate, propionate or butyrate was 20·7 ± 1·0%, 28·3 ± 1·5%, 30·2 ± 0·5% and 31·3 ± 0·2%, respectively. The calculated efficiency of utilization for fattening (k_f) of the infused energy sources was 69·9 ± 8·4%, 84·0 ± 3·4% and 86·0±2·0% for acetate, propionate and butyrate, respectively. In most instances k_f did not vary with the length of the period of infusion but in one sheep there was an adverse response to the infusion of the acetate mixture, and during the first week of infusion k_t was only 29·3%. During the third and fifth weeks of the infusion the corresponding values were 76±3% and 72±5%.