نویسندگان
1 گروه پرورش و تولید طیور،دانشگاه تربیت مدرس
2 واحد تحقیق و توسعه شرکت زربال
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Poultry requirments for vitamins and minerals are met from two sources feed ingredients and
premixes.In practical poultry nutrition, the role of feed ingredients is over looked. This experiment
was conducted to evaluate the effects of the time of vitamin and mineral premixes withdrawal on
growth and economic performance of broilers. Four hundred and fifty, one day-old male broiler
chickens (Ross 308) were used in a completely randomized design with 6 treatments of 5 replicates.
Chicks were fed on a common starter diet formulated based on corn and soybean meal, with common
vitamin and mineral premix (VMP) levels (0. 25 % each) for the first week. Then, the treatments 1 to
6 were constructed, on the basis of withdrawal time of VMP, in a way that treatment numbers were
represented the number of weeks fed on VMP supplemented diet. The results showed that VMP
withdrawal from 7, 14 and 21 days of age decreased daily weight gain and feed intake significantly
(p<0. 01), and impaired feed efficiency (p<0. 01). While VMPwithdrawal from day 28 and day 35, did
not influence weight gain, feed intake and feed efficiency. Relative weights of abdominal fat, bursa of
fabricius and spleen, and carcass yields were not influenced by VMPwithdrawal. The overall results
of the present study, considering economical aspects showed that the removal of vitamin and trace
mineral supplements from 7 days prior to slaughter can reduce production costs without negative
consequences on growth performance of broiler chickens
کلیدواژهها [English]
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