The chemical composition, energy and amino acid digestibility of cowpeas used in poultry nutrition
The aim of this study was to determine the chemical composition and digestibility of cowpeas for use in poultry diets. Three cowpea cultivars, Glenda, Agrinawa and Indigenous were evaluated. The cultivars showed a relatively narrow range of protein concentrations (253.5 to 264.3 g/kg). The concentrations of amino acids (AA) varied among the cultivars. Dietary crude fibre levels varied from 51.5 to 58.1 g/kg. The cultivars were almost devoid of lipid and calcium, but were relatively high in phosphorus. The apparent and true metabolisable energy (AMEn and TMEn) values ranged from 9.88 to 10.02 and 10.29 to 10.78 MJ/kg DM, respectively. The mean digestibilities of the AA's ranged from 72.8 to 81.0%, with methionine having the highest digestibility and lysine the lowest. Cowpeas appear to be suitable for use in poultry feeds, their composition being equivalent to plant protein sources such as lupins and field peas, but lower in most nutrients compared with soybeans and canola.