THE EFFECT OF OXYTETRACYCLINE ON THE PERFORMANCE AND SERUM MINERAL LEVELS OF KIDS REARED WITH OR WITHOUT THEIR DAMS

Abstract

Investigations were conducted to assess the effect of supplemental oxytetracycline-HC1 at various levels on performance and serum mineral levels of kids reared on two different systems of management, namely, kids reared with their dams and those reared artificially on cow's milk, with a view to determine the optimal level at which the best performance could be achieved. Forty-eight three-day-old goat kids weighing between 1.25 and 2.05kg with a mean weight of 1.79kg were used in this study. A group of animals assigned to a specific rearing method were randomly allotted to four treatment groups (0, 13.2, 19.8 and 26.4mg of oxytetracycline-HC1 daily). The experiment lasted for 84 days. The results on performance showed that the voluntary milk intake and liveweight gain of kids reared with their dams were comparable with their counterparts on cow's milk for the first two weeks of the experiment. Thereafter, the milk intake of kids reared with their dams diminished due to fall in dam's milk yield, resulting in lower weekly liveweight gain. At the end of the experiment, the mean weekly liveweight gain of kids reared on cow's milk were higher (241.90 vs 295.20g). However, kids reared with their dams exhibited better feed efficiency than their counterparts on cow's milk, indicating that the observed higher weekly liveweight gain was as a result of the higher milk intake. Oxytetracycline-HC1 supplement enhanced weekly liveweight gain of kids reared with their dams. The overall mean weekly liveweight gain for kids on treatment levels (0, 13.2, 19.8, and 26.4mg of oxytetracyclne-HC1 daily) were 171.70, 216.56, 216.39 and 333.80g, respectively, for kids reared with their dams. The corresponding values for kids reared on cow's milk were 330.56, -315.31, 289.59 and 246.34g, respectively. Oxytetracycline-HCl supplement did not depress the serum levels of Ca, Na, K, Cu, and Fe, particularly when fed between 13.2 and 19.8mg/day. Slight decrease in the serum levels of P and Mn compared to the control were observed, although the differences were not significant. However, oxytetracycline significantly depressed the serum Mg levels, particularly in kids reared with their dams. Results obtained with the two systems of management suggested that oxytetracycline-HC1 was capable of improving the performance of kids reared with their dams. Oxytetracycline-HC1 fed as supplement to kids already adequate in milk intake was not encouraging, since no apparent improvement in performance over the unsupplemented kids was produced. Oxytetracycline- HC1 supplement at level of 26.4mg/day is recommended for adequate liveweight gain and optimal feed efficiency without adverse effect on the serum mineral status of the pre-weaned kids.