Effects of serial withdrawal of dietary vitamin mineral premixes on performance, carcass characteristics and organs weight of broiler chickens

Abstract

Effects of serial withdrawal of dietary vitamin mineral premixes (VMP) on performance, carcass characteristics and organs weight of broiler chickens was investigated in an experiment lasting 42 days. A total of 224, one-day old Arbor acre broilers chicks were randomly allotted to seven dietary treatments of 32 chicks each comprising quadruplicate of eight birds per replicate. Basal starter and finishers diets had VMP withdrawn for 6, 5, 4, 3, 2, 1 and 0 weeks to obtain  T1, T2, T3, T4, T5, T6 and T7 dietary treatments respectively. Birds were offered feeds and water ad libitum. The design of the experiment was completely randomized design. Only chicks body weight gain was significantly reduced (P<0.05) at week 1 by VMP withdrawal while other indices of performance were statistically similar (P>0.05). Disparity of performance indices increased (P<0.05) as weeks of VMP withdrawal increased. Dressing percentages were 68.64, 75.41, 73.36, 79.34, 84.24 and 76.84% for birds on T2, T3, T4, T5, T6 and T7 respectively, and were highest for birds on T6. Prima cuts, external offal, organs weight excepting thigh, bile, liver, spleen and abdominal fat deposition were all significantly reduced (P<0.05) by VMP withdrawal. Study revealed that vitamin-mineral premixes could be successfully withdrawn from broilers diets from day 35 of production without any effect on performance and carcass indices of birds.