Untreated and formaldehyde treated protein concentrate mixture in the feeds of bulls

Twelve bulls within the age period 113—294 days were used in an experiment in which the effect of formaldehyde treatment of protein on the live weight gain and feed utilization was studied. Their rations were a combination of a protein concentrate mixture, barley, mineral and vitamins according to nutrient requirements for a growth rate of 1000 g/animal/day. Oats and barley straw was available ad libitum. In the experimental group the protein concentrate mixture was treated with formaldehyde, 0,88 g/100 g crude protein, whereas in the control group it was untreated. The proportion of treated protein was 45 % of the total protein in the diet. The study involved feeding trials, digestibility and nitrogen balance trials, and rumen fluid investigations. The live weight gain of the bulls in the experimental group was 10 % better than that of the control group. The amount of feed used per kg live weight gain was 8 % less in the former group than in the latter. The differences in both cases were, however, not significant (P > 0,05). The differences in the digestibility and nitrogen balance and in the pH, ammonia and VFA concentrations of the rumen fluid between the groups were small and insignificant (P > 0,05)