Chemical composition and sensory evaluation of meat of tswana hens fed different protein sources: mopane worm, bambara groundnut and morama bean

Abstract

This study investigated the chemical composition and sensory evaluation of meat of Tswana hens fed diets containing mopane worm (Imbrasia belina, Westwood) or Bambara groundnut (Vigna subterranea (L) Verde) or morama bean (Tylosema esculentum, Burchell A. Schreiber) as different protein sources under intensive management system. Sixty Tswana hens (25 weeks old) were bought from a local farmer and reared up to 38 weeks of age on diets containing T. esculentum or V. subterranea or I. belina and a commercial layer diet as a control. Experimental diets met the nutritional composition of control diet. Whole thighs, drumsticks obtained from the carcasses at week 28, 33 and 38 were deboned. The thigh, drumstick meat and bone were analysed for phosphorus (P), calcium (Ca) and potassium (K) using AOAC methods. Furthermore, boiled 2 x 5 cm portions of drumsticks, breasts and thighs were organoleptically assessed for flavour, odour, juiciness, tenderness and firmness by untrained panelists (15 males and 15 females) using a 5-point Likert scale. Bone P and Ca were high in all treatment diets at 28 weeks compared to 38 weeks of age. The meat DM, CP, P, Ca and K and bone P, Ca and K contents were not significantly affected by treatment diets. Organoleptic quality from all treatment groups and across different ages received moderate (3.52) to good rating (4.13). In conclusion, Imbrasia belina (Mopane worm) or Vigna subterranea (Bambara groundnut) or Tylosema esculentum (Morama bean) can replace soybean meal in Tswana hens without compromising meat and bone chemical composition and also organoleptic qualities.