Effect of Clenbuterol on Ammonia and Urea Content in Blood Plasma and Ruminal Fluid of Fattening Lambs

V. BANSKALIEVA and S. ALEXANDROV

Institute of Animal Science, BG-2232 Kostinbrod, Bulgaria

Abstract

BANSKALIEVA, V. and S. ALEXANDROV, 2000. Effect of clenbuterol on ammonia and urea content in blood plasma and ruminal fluid of fattening lambs. Bulg. J. Agric. Sci., 6: 687-690

Two experiments, of three groups of 6 lambs each (i.e. control and two experimental) were conducted. In the course of 6 weeks all the animals were fed with diets containing 4.3 and 6.0 MJ energy and 140 and 200 g of protein per kg/diet, for the first and second experiment respectively. Besides, the daily diet of the experimental groups was supplemented with 10 mg clenbuterol. Samples of blood and ruminal fluid for analysis of ammonia and urea contents were taken at the end of the treatment from the control and one of the experimental groups, and from the second experimental groups a week later. In the meantime the animals of the last groups were not given clenbuterol.
It was established that clenbuterol decreased urea content in the ruminal fluid and blood plasma of lambs from both experiments, but better manifested in the ruminal fluid of animals reared under conditions of higher protein and energy level. The content of ammonia sharply decreased in animals from the first experiment, but was elevated more than twice in the blood plasma of lambs from the second experiment. After 7 days pause, the levels of some of the examined parameters changed and reached the values of control groups. It is concluded that the effect of clenbuterol depends on the protein/energy level of diet.

Key words: lambs, clenbuterol, ammonia, urea, plasma, ruminal fluid