Growth performance and physiological responses of broilers fed Stylosanthes hamata leaf meal in a hot tropical environment

Abstract

Background: Forage plants are considered an essential source of vitamins, protein and energy and could decrease the intake of the conventional diets by up to 10% if young quality forage plants are offered and about 7% of a broiler's daily protein needs and 3% of their daily calorie needs can be met by pasture. However, there is a paucity of data on the quantification of the herbage intake in broiler chickens. Objectives: This trial was designed to determine the performance and physiological response of broilers fed diets containing Stylosanthes hamata leaf meal (SHLM) at 0%, 1%, 5%, 10%, 15% and 20% inclusion (weight for weight) in a basal diet of poultry. Methods: Two hundred and forty-day-old Arbor Acres broiler chicks were used for this trial. They were allocated at random to each of the 6 dietary treatment groups with 4 replicates of 10 chickens each. The study lasted for 35 days, during which data were collected weekly. Results: Results indicated no difference (p > 0.05) in body weight gain, feed consumption and feed conversion ratio of broiler chickens across all ages. Although the plasma triiodothyronine (T3) concentration of the birds was influenced at the sixth week of age, there was no consistency in the trend. At the eighth week of age, chickens on 15% SHLM had significantly (p < 0.05) higher cortisol (3.22 ng/mL) concentrations compared to 10% (3.13 ng/mL) and 20% (3.16 ng/mL) SHLM treatment groups. Treatment groups, regardless of the age of the chickens, had similar (p > 0.05) mean plasma creatinine values. Conclusions: The study concluded that SHLM could be incorporated into broiler feed up to 20% without a deleterious impact on physiology and performance indices.