Nutritive effect of cabbage (Brassica oleracea) on growth, obesity, lipidaemia and haematology in broiler and pullet chickens
Efficacy of cabbage (Brassica oleracea) for ameliorating the adverse metabolic syndrome side-effects of genetically improved growth rate in chickens was examined. Sixty-four (64) day-old birds (32 Marshall Broilers and 32 Harco Black Pullets) were randomly assigned to groups of eight genotype-matched birds in a 2-factor layout within a Completely Randomized Design (CRD). Within genotype, each group was randomly assigned one of four diets (basal/control diet containing 0% cabbage, and, basal diet supplemented with 3%, 6% or 12% cabbage) for 4 weeks. All birds were fed an un-supplemented Broiler finisher diet from week 4 - 8. Bodyweight and Body Mass Index (BMI) were determined weekly. Blood Packed Cell Volume (PCV), Haemoglobin (Hb), White Blood Cells (WBC), Red Blood Cells (RBC), neutrophils, lymphocytes, monocytes, basophils and eosinophils), Total serum Cholesterol (TC), High Density Lipoprotein (HDL) and Low Density Lipoprotein (LDL) were determined at age 4 weeks. Irrespective of diet or age, Broilers exhibited significantly greater (p<0.05) body weight, adiposity, and lipidaemia than Pullets, and no interactions between cabbage and genotype were observed for the same traits. Dietary cabbage at 3%, irrespective of genotype significantly (p<0.05) improved body weight beyond week 5 while no significant effect was observed on body fatness as measured by BMI. Cabbage supplementation suppressed broiler eosinophil levels, indicating effects on mediators of innate immune surveillance, but did not influence any other blood haematological parameter, though Broilers exhibited higher (p<0.05) total WBC count and proportion (%) of WBC represented by neutrophils, basophils and eosinophils. In Contrast, Pullets exhibited higher RBC, PCV, and Hb, and lymphocyte and monocyte differential counts. Dietary Cabbage had a nutrigenetic effect on cholesterol: Reduced TC and LDL in Broilers in contrast to its effect in increasing the same lipids in Pullets. Cabbage however lowered HDL Cholesterol (p<0.05) in both genotypes, though the threshold of effect was higher (12%) in Pullets (3%). Thus Cabbage is effective in lowering heart disease risk through lowering of lipidaemia in Broilers, and improves bodyweight at market age (7-8 weeks) at 3% dietary supplementation level.
KEYWORDS: Cabbage, Broiler, Pullet, Nutritive, Metabolic syndrome.