Growth performance, haematological and biochemical parameters in broilers fed diets with varying levels of Vernonia amygdalina leaf meal

Growing concern about the use of antibiotics as growth promoters in animal diets and their health effects on consumers of poultry products has made it necessary to search for suitable alternative growth-promoting agents, in particular medicinal plants. Aim of this study was to determine the effects of dietary supplementation of Vernonia amygdalina leaf meal (VALM) on haematological and biochemical parameters and growth performance of broilers chickens. Four hundred and eighty (480) day-old Cobb chicks were randomly allocated to four dietary treatment diets: a basal diet (V0) (control group with 0% of VALM); basal diets with 1 (V1), 2 (V2) and 3% VALM (V3) having 4 replicates of 30 birds each in a completely randomised design. Birds were managed conventionally on a deep litter system for a period of 6 weeks. Data on body weight, feed intake, feed conversion ratio and blood parameters were collected. In birds of the V2 and V3 groups feed intake was significantly lower (P = 0.012) than in group V0. In chickens of the groups V0 and V1 the feed conversion ratio was similar but significantly higher than in groups V2 and V3. Final body weights and weight gain were significantly (P = 0.008) higher in the birds of the V2 group compared with chickens of the other treatment groups. Also, the weights in groups V0 and V1 were lower than in group V3. Except for packed cell volume and white blood cells, the results showed no differences between the groups in the other haematological parameters measured. Total cholesterol and low-density lipoprotein cholesterol concentration were lower in the birds offered VALM than in the control group. However, there was no difference in total protein but the values of albumin were higher (P = 0.002) with VALM application, especially in birds of the V2 group. It can be concluded that supplementation with VALM at a dose of 2% improved growth performance and haematological and biochemical parameters in broilers.