Physiological Responses of Broiler Chickens to Dietary Inclusion of Provitamin A Cassava Leaf Meal as a Protein Substitute for Groundnut Cake
A total of 120 broiler chickens were used to evaluate the physiological response of birds fed diets containing Pro-Vitamin A cassava leaf meal (PVACLM) as a replacement for groundnut cake (GNC) protein. This study aimed to assess the effects of graded levels of PVACLM on hematological and serum indices, as well as the economic implications of using this alternative protein source in broiler nutrition. The research was conducted at the Poultry Unit of the Teaching and Research Farm, Michael Okpara University of Agriculture, Umudike. The birds were weighed at arrival, brooded for two weeks, and randomly assigned to four dietary treatment groups (T1 to T4) with 30 birds per treatment and 3 replicates of 10 birds each. The experimental diets contained 0% (control), 5%, 10%, and 15% PVACLM, formulated to replace groundnut cake either partially or fully. Cassava leaves were harvested from the National Root Crops Research Institute (NRCRI), wilted overnight, air-dried under shade for five days, and milled into meal. Standard poultry management practices, including ad libitum feeding, access to clean water, routine medication, and vaccinations, were followed throughout the 8-week study. At the end of the trial, blood samples were collected for hematological and serum biochemical analysis. The results revealed significant differences (P<0.05) in several hematological parameters. Red blood cell (RBC), packed cell volume (PCV), and hemoglobin (HB) increased with rising levels of PVACLM inclusion, while white blood cell (WBC) counts decreased. The highest values for RBC (3.50 ×10⁶/µL), PCV (29.67%), and HB (11.47 g/dL) were recorded in T3, while T1 (control) had the lowest values of 2.79 ×10⁶/µL, 24.66%, and 9.23 g/dL, respectively. No significant differences (P>0.05) were observed in platelet counts, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), or mean corpuscular hemoglobin concentration (MCHC) across treatments. Serum biochemical indices showed significant variations (P<0.05) in total protein, globulin, cholesterol, and glucose. Total protein and globulin increased with PVACLM inclusion, while cholesterol levels decreased. The highest total protein (3.49 g/dL) and globulin (1.32 g/dL) values were found in T3, whereas the highest cholesterol (85.70 mg/dL) was recorded in T1, with the lowest (74.55 mg/dL) in T4. Serum glucose increased progressively with higher PVACLM levels, with the peak value (172.33 mg/dL) observed in T4. The combination of GNC and PVACLM provided a balanced amino acid profile and enriched the diet with lysine, contributing positively to the health and physiological performance of the birds. The study concludes that Pro-Vitamin A cassava leaf meal is a viable alternative protein source for broiler chickens. Its use can reduce feed costs and enhance sustainability in poultry production without adverse effects on bird health.
