The use of methane‐utilising bacteria as a source of protein for young chicks1

Abstract

Two strains of continuously‐grown, methane‐utilising bacteria were found to contain 8.96 and 9.95% N and a favourable pattern of essential and non‐essential amino acids, the concentrations of which were generally higher than those previously observed in batch grown organisms (D'Mello, 1972). One of these strains has been evaluated as a protein source for young chicks. Four diets were employed : the first was a control maize‐soybean diet supplemented with methionine; the second was similar to the control diet except that 10% bacterial protein was included largely at the expense of soybean; the third, a low‐protein diet, was identical to the second in all respects except that the bacterial protein source was substituted by an equivalent weight of ground maize ; the fourth consisted mainly of maize and dried whole egg served as an additional control diet. There were no significant differences in growth, efficiency of food conversion or nitrogen retention between the control group and the group receiving the bacterial protein. Furthermore, chicks in these two groups performed significantly better than either those fed on the low‐protein diet or those fed on the whole egg diet. Amino acid and uric acid concentrations in plasma were similar in the control and bacterial protein groups although levels tended to be lower in chicks consuming the low‐protein diet. Activities of glutamic‐oxalacetic and glutamic‐pyruvic transaminases in plasma were similar in all dietary groups. These results suggest that the strain of methane‐oxidising bacteria used in the present study is potentially a useful source of protein for non‐ruminant animals.