| dc.description.abstract | 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. | en |
