The Use Of Fibre Degrading Enzyme Supplementation In Corn Cob Based Diets For Broilers: Effects On Growth, Blood And Carcass Parameters

ABSTRACT This research was carried out to determine the growth performance, carcass characteristics and selected blood parameters of broilers fed increasing levels of corn cobs (CC) as a replacement (50% or 100%) for wheat bran (WB), with or without fibre degrading enzymes (E). A total of 175 day-old chicks were used in this trial which lasted 42 days. Birds were randomly allotted to five dietary treatments in a completely randomised design. Treatments were labelled as T1 (0% CC), T2 (3% CC), T3 (3% CC + E), T4 (6% CC) and T5 (6% CC + E). Each treatment was replicated 5 times with 7 birds per replicate summing up to 35 birds per treatment. Water was offered ad-lib. Also feed was offered as weighed ad-lib with waybacks to determine feed intake. Data was analysed using the GLM procedure of SAS and significant differences separated by means of SNK test at 5% probability level. Growth performance variables were not significantly different (P > 0.05). For carcass characteristics T4 and T5 had significantly heavier (P < 0.05) full and empty gizzard weight than other treatments. Birds fed T1andT5 had heavier (P < 0.05) full and empty intestines than T2, T3 andT4. All blood parameters analysed were not significantly different (P < 0.05) with the exception of serum globulin and uric acid. TI recorded 199.0 µmol/L for uric acid which was similar (P > 0.05) to T2 and T3 but had a lower value (P < 0.05) compared to T4 (439.38 µmol/L) and T5 (367.26 µmol/L). Regarding globulins, the value observed (6.86 g/dL) among T1 birds was significantly lower (P < 0.05) than birds in T4 (21.63 g/dL). All the biochemical and haematological parameters were within the normal reference range apart from haemoglobin among birds in T3. It can be concluded from the experiment that feeding broilers with a diet containing up to 6% corn cobs with or without dietary enzyme had no negative effects on the growth performance, health status, carcass quality and weight. It was also found that corn cobs can replace wheat bran partially or totally up to 6% in poultry diets without affecting the growth, carcass and blood profiles. From the results, the cost of feed/kg progressively reduced as level of corn cob and fibre in the diets increased such that it was 12% cheaper to raise broilers on T5 than the control.