The effect of xylazine, cisapride, and naloxone on myoelectric activity of the ileum, cecum, and proximal loop of the ascending colon (PLAC) was determined in 4 healthy Jersey cows implanted with 8 pairs of bipolar electrodes. A 4 X 4 Latin square design was used. The treatments included xylazine (0.04 mg/kg of body weight), cisapride (0.08 mg/kg), naloxone (0.05 mg/kg), and 0.9% sodium chloride solution (20 ml). All treatments were administered IV during early phase I of the migrating myoelectric complex in the ileum. Myoelectric activity was recorded for 4 hours after treatment, and data were analyzed for each hour separately. Xylazine significantly (P < 0.05) increased the duration of phase I of the first migrating myoelectric complex in the ileum to 220.72 +/- 26.89 minutes, compared with 30.91 +/- 10.11 minutes after administration of 0.9% sodium chloride solution. The number of cecocolic spikes per minute per electrode and the duration of cecocolic spike activity (percentage of recording time) were significantly (P < 0.05) decreased for the first 3 hours, and the number of propagated spike sequences in the cecum and PLAC was significantly (P < 0.05) decreased for the first 2 hours after administration of xylazine. Significant difference was not found between control and either,cisapride or naloxone treatment of healthy cows. However, during hour 1 after treatment with cisapride, number of spikes per minute, duration of spike activity, and number of propagated spike sequences were highest, compared with the other treatments. It was concluded that naloxone at the dosage used in this study was not suitable for medical treatment of cecal dilatation in cattle, when hypomotility of the cecum and PLAC must be reversed. Xylazine should not be used for relief of signs of pain in cases of cecal dilatation, because it significantly reduced myoelectric activity of the cecum and PLAC for at least 2 hours after treatment. Furthermore, results of this study indicated a trend (P > 0.05) toward increase of cecocolic myoelectric activity after administration of cisapride. It is the authors' opinion that the potential benefit of cisapride for medical treatment of cecal dilatation in cattle needs further evaluation.

Study of peculiar features of protein metabolism of healthy colts in the first three months of life was realized in the conditions of the Republic of Belarus. Research results showed that there was a tendency of increasing of hemoglobin concentration up to 150,270+/- 4,73 g/l, number of total protein of blood serum – up to 60,33 +/- 1,33 g/l, and the decreasing of uric acid up to 97,33 +/- 10,72 micromole /l. Quantity of beta-1 and alpha globulin fractions of serum protein fluctuated a little – from 10,78 +/- 3,69% up to 8,44 +/- 1,24% and from 25,12 +/- 4,84% up to 22,06 +/- 4,93%, respectively. The most essential changes of protein metabolism were stated at two month old colts, which had urea concentration of 5,25 +/- 0,23 micromole/l, alanine aminotransferase activity – 66,92 +/- 3,16 units/l, creatine content increased up to 77,37 +/- 5,83 micromole /l; and there was the lowering of aspartate transaminase level up t159,5 +/- 8,1units/l. There was stated the lowering of albumin quantity up to 32,07 +/- 2,19%, and increasing of alpha-1, alpha2- and beta2- globulin fractions up to 7,52 +/- 1,23%, 14,98 +/- 1,41%, 11,82 +/- 1,04%, respectively. At the age of three months the quantity of urea and creatinine in blood serum of colts remained at the same level, alanine aminotransferase activity decreased on 21,56%, and aspartate transaminase increased up to 204,33 +/- 10,37 units/l. At this period the quantity of albumin fractions was 44,56 +/- 6,59%., concentration of alpha-1, alpha2- and beta2- globulins decreased on 10,64%, 30,04% and 34,52%, respectively