The Influence of Monensin on Calf Performance and Selected Biochemical and Hematological Parameters of Blood

Veterinarni Medicina 37, 1992, 501-507

The aim of this study was to find out the influence of monensin, a ionophore antibiotic, on calf performance and selected physiological parameters. Monensin is a product of Streptomyces cinnamonensis. It has effects on all Gram-negative microbes, such as Escherichia coli, salmonellas, pseudomonads and vibria. It has a small effect on Gram-positive microbes. At the beginning of the experiment eight young crossbred bulls [C X N] at the age of three weeks were weighed and divided into two groups, experimental and control ones. Calves were kept in individual boxes and fed acidified whole milk [2 ml of 85 % formic acid per 1 litre of milk]. They had a free access to concentrates [COT], hay and drinking water. The calves received 3 lt. of whole milk twice a day until the age of eight weeks. 0.5 mg of monensin per 1 kg live weight were served orally to calves of the experimental group every day. Monensin was made by the Spofa Corporation, Prague. Daily intake of feed was recorded and the calves were weighed once a week. Blood samples were taken from the jugular vein before the beginning of the experiment, and in the period from the fifth to the tenth week of age, always before morning feeding. The average daily live weight gain was 0.452 kg and 0.471 kg for the control and experimental group, respectively, during the milk feeding period, the index being 104.2 (Tab. I). Tab. II shows the average feed intake per 1 kg live weight gain. The concentrate consumption rate per 1 kg live weight gain was 0.812 for the control group and 0.676 for the experimental group (83.25 %). Hay consumption rate was 0.360 and 0.397 for the control and experimental group, respectively [110.28 %]. The results of selected haematological and biochemical observations are shown in Tabs. III, IV and V. During the metabolism trials both groups showed blood haemoconcentration accompanied by neutrophilia as a result of dysentry. A slight decrease in serum iron levels was detected in both groups in the last days of the experiment. In comparison with the control group, the levels of serum cholesterol and calcium were higher in the experimental calves while the activity of aminotransferases was depressed. Calves on monensin had the significantly higher counts of leucocytes in the 10th week of age. Even though there were minor differences among the blood parameters, no further important effect of monensin on blood characteristics was recorded

FULL PAPER on request
« back