Effect of Partial Replacement of Maize with Full-Fat Soya Bean or Soya Bean Oil on the Growth Performance, Gut Ph, Carcass and Bone Traits of Ross 308 Broiler Chickens.

Abstract

Soya bean (SB) products are valuable protein and energy source commonly used in poultry diets. Thus, this study was designed to investigate the effect of partial replacement of maize with full-fat soya beans or soya bean oil on growth performance, gut pH, carcass traits and bone characteristics of Ross 308 broiler chickens. A total of 200 broiler chickens were randomly assigned to four dietary treatments T1(regular soya bean diet), T2(full fat soya bean diet), T3(soya bean oil diet) and T4 (regular soya bean diet plus full fat soya bean diet) in a completely randomized design (CRD), with five replicate, ten birds per pen and fifty birds per treatment. Growth performance indicators such as body weight, body weight gain, feed intake, livability, and feed conversion ratio were assessed every two weeks. Gut pH, carcass traits, bone characteristics were also measured. Results showed that on d 14 there was no significant (P > 0.05) effect of the treatment on all the growth parameters measured, numerically, all the growth parameters increased but on d 28 of the study, dietary treatment had a significant (P < 0.05) influence on feed intake which increased with birds on T3 recording the highest feed intake but statistically was similar to T4 and T1 (P < 0.05). Also, from d 42 to 56 there was an increase with a significant difference on dietary treatments on body weight, body weight gain and feed intake of the birds (P < 0.05). Dietary treatments had no significant effect (P > 0.05) on gut pH across all segments. Gizzard and fat pad were significantly (P < 0.05) influenced by the dietary treatment. Regarding bone traits, significant differences (P < 0.05) were observed only in tibia length, with birds on T1, T2, and T4 showing longer tibiae than those on T3. In terms of cost benefits, there was significant difference (P<0.05) between the treatment means. Birds on soya bean oil diet (T3) and conventional plus full-fat soya bean diets (T4) resulted in increased (p<0.05) price per bird, profit, and Performance Efficiency Index (PEI) compared to the birds fed full-fat soya bean diet. In conclusion, using soya bean oil or full-fat soya bean as an alternative energy source by reducing the maize in a diet had positive impact on the growth performance especially at the early stage, carcass traits and tibia length of the birds were optimal.