| Abstract: | Digestive activities were studied in test calves (n = 12) in relation to age and feed intake. The calves were isolated after birth from adult cows. Since the 14th day of age, milk replacers were fed with concentrate feed mixture TG and alfalfa hay, i.e. the calves were in the period of plant feeding. The investigation lasted from the end of milk feeding (50th day) to the age of six months. Overall health condition was studied clinically. The characteristics of digestive activities studied in rumen fluid at weekly--monthly intervals were pH, ammonia content, total content of volatile fatty acids, content of particular volatile fatty acids, incidence and number of infusoria. At the age of 50 days, actual pH of rumen fluid was on the average 6.07 and it ranged from 5.84 to 6.76 in the next period. Ammonia content was the highest at the age of 50 days (21.49 mmol/l rumen fluid), then it dropped to 9.83 mmol/l rumen fluid at the age of 180 days. The average total concentration of volatile fatty acids (C2-C5) made 117.00 mmol/l during the first examination, it increased to 132.98 mmol/l at the age of 84 days, and it dropped to 94.16 mmol/l rumen fluid at the age of six months. A similar tendency was found in the volatile fatty acids. The infusoria were found out only at the age of 120 days--their numbers were 155 000 per ml; at the age of 180 days their numbers rose to 368 000 per ml rumen fluid. No disorders of health condition were recorded during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS) |
