Effects of Varying Levels of Neem (Azadirachta indica) Leaf Meal in Layer Diets on the Haematological and Serological Indices, and Faecal Bacterial Counts of Layers

Abstract

An experiment was conducted to investigate the effects of varying levels of Neem (Azadirachta indica) leaf meal in the diets of layers on the haematology, serology and faecal bacterial counts of laying pullets. Five layer diets formulated to contain 0%, 2.5%, 5.0%, 7.5% and 10.0% Neem Leaf Meal (NLM) were fed to a total of one hundred and fifty (150) 20-week old Shikka Brown layers. The birds were randomly assigned to 5 treatment groups of 30 birds each made up of 3 replicates of 10 birds per treatment. The diets were formulated to contain approximately 2500kcal/kg ME and 17% crude protein. NLM had no significant (P>0.05) effect on packed cell volume (PVC), red blood cell count (RBC), white blood cell counts (WBC), Haemoglobin, MCV, MCH, MCHC and plasma protein of the layers. NLM produced significant (P<0.05) differences between treatment means in the neutrophils, lymphocytes, basophils and monocytes counts but not in eosinophils. The neutrophil counts of layers fed diets containing 7.5% NLM were significantly (P<0.05) higher than those of the control, 2.5% NLM and 5.0% NLM treatment groups. Lymphocyte counts obtained from layers fed 5.0% NLM were significantly (P<0.05) higher than those of the control and other NLM treatment groups. Inclusion of NLM in the diets of the layers beyond 5% significantly (P<0.05) lowered basophil counts, while monocyte counts increased with increase in dietary NLM up to 5%, and declined thereafter. Serum albumins, cholesterol and total proteins were similar (P>0.05) between treatments, while total bacterial counts from cultures of faecal samples of the layers showed highly significant (P<0.01) progressive decline with increase in dietary level of NLM. It was concluded that as much as 10% dried Neem Leaf Meal could be included in the diets of laying chickens without deleterious effects on their blood constituents, serum biochemistry, and with the benefit of reducing possible risks of infection from pathogenic bacteria.

Keywords: Neem Leaf Meal, Azadirachta indica, haematology, serology, layers, bacterial counts