Performance of broiler finishers fed graded levels of processed castor oil bean (Ricinus communis L) meal supplemented with DL-methionine

Résumé

A feeding trial was conducted to determine the effect of graded levels of dehulled and cooked castor oil bean (Ricinus communis L) meal (CBM) and supplementary DL-methionine on growth performance and certain blood parameters of broiler finishers. One hundred and eighty 6-week old broiler birds (Anak strain) were randomly divided into 12 groups of 15 birds each. The groups were randomly assigned to 12 isocaloric (2.90 Mcal/kgME) and isonitrogenous (21.00%CP) diets in a 4 x 3 factorial arrangement involving a control (0%), three cooked castor oil bean meal levels (10,15 and 20%) and three DL-methionine levels (0,0.25 and 0.5%). Each treaiment was replicated thrice with 5 birds each. Feed and water were supplied ad libitum from 42 to 70d of age. The results showed that above 15% CBM inclusion level, average daily feed intake (ADFI) and average daily weight gain (ADWG) were significantly (P<0.05) decreased. There were also significant reductions (P<0.05) in efficiencies of feed and protein utilization, and in apparent retention of dry matter (DM), nitrogen, ether extract (EE) and nitrogen-free extract (NFE). While packed cell volume was not significantly (P>0.05) affected by CBM or DL-methionine, haemoglobin concentration (Hb) was significantly (P<0.05) increased at 20% CBM level. Supplementation with DL-methionine improved (P<0.05) weight gain at the 15 and 20% levels of CBM inclusion; improved Hb and efficiencies of feed and protein utilization at the 20% level of CBM inclusion, improved nitrogen retention at the 0% level of CBM inclusion; improved EE retention at the O and 20% levels of CBM inclusion, and improved NFE retention at the 15% level of CBM inclusion. The results of this study indicate that processed CBM can be included in broiler finisher diet at 15% level with DL-methionine supplementation to obtain normal growth in broiler birds.