Effect of biotin supplementation on performance of chicken broilers
Three experiments were carried out to evaluate the effect of biotin supplementation on performance of broiler chicken. Rovimix H2 was the source of available biotin. Experiment One basal diet was formulated to provide 3152 Kcal of metabolisable energy (ME) and 230 g of crude protein (CP) per kg. The supplementary available biotin in the four experimental diets was O. 80. 160 and 320 J.lg/kg of the diet. Experiment Two basal diet contained 2900 Kcal of ME and 196 g of CP per kg. which was supplemented with biotin at the rate of 0, 50, 150 and 300 J,lg/kg of the diet, to produce four experimental diets. In Experiment Three, a low and a high protein basal diets were formulated. To each of the basal diet, biotin was supplemented at the rate of 0, 100 and 200 J.lg/kg of diet, to produce six experimental diets. The low protein diets provided 2869 Kcal of ME and 216 g of CP per Kg. The corresponding values for the high protein diets were 3282 Kcal of 260 g. In the three experiments, each diet was given to a group of ten chicks, replicated four times, with equal replication for male and female chicks. Experiment One and Two basal diets provided 142 and 355 J,lg/kg of total biotin while the available biotin was 108 and 166 J,lg/kg of the diet, respectively. In Experiment Three total biotin in the low and high protein diets were 171 and 175 J,lg/kg. while available biotin was 88 and 132 J.lg/kg, respectively. Available biotin in basal diets and supplementary biotin was 51 t T mr d up to obtain total available biotin in each diet. Experiment One results showed that biotin supplementation had no effect (P<O.01) on growth rate, feed intake, feed efficiency, mortality or (FKLS), although it tended to improve growth rate up to 268 ug/kg. In Experiment Two, supplementation had a quadratic effect on weight gain. At 21 days of age, supplementation had a significant effect (P<O.05) on weight gain wit.h t.he highest response obtained at a level of 266 Il.g:lkg of the diet. At. 42 days of age supplementation failed to attain statistical significance, although the best performance was obtained at an intake of 166 ~lg/kg of the diet. Supplementation had no effect on feed intake, feed efficiency, mortality or FKLS. In Experiment. Three, response to supplementation varied with sex and dietary protein. Male chicks on high protein diet showed a linear response to supplementation. However, female chicks on the high protein diets and both male and female chicks on the low protein diets showed no response to biotin supplementation. Available biotin in fish meal and soybean meal was unusually high at 512 and 315 Jlg/kg of the diet respectively, while the content in wheat and white sorghum was o and 168 ~lg/kg respectively. Results from this study showed that biotin supplementation improved growth rate in sorghum based diets but this improvement became less clear with age. A level of 266 ~lg/kg and 166 Jlg/kg of diet, were found desirable in the early and late stages of growth. In wheat based diets, biotin supplementation did not elicit any significant response probably due to under-estimation of available biotin in wheat. Under field conditions, the conventional raw materials are likely to provide between 59 and 88 pg/kg of the diet. making supplementation to 166 ~g/kg, particularly in the high protein diets, desirable. A better understanding of total and available biotin in Kenya feeds stuffs is desirable.