Concentrate diets fed sole to rabbits by smallholder farmers in Greater Port Harcourt City, might not satisfy their nutrient requirements

Abstract

Nutritive value of concentrate feeds fed to rabbits by smallholder farmers in Greater Port Harcourt City (GPHC) were assessed in two of its eight Local Governments. Thirty-five rabbit farmers; 20 and 15 from Obio-Akpor and Ikwerre, respectively, were sampled, using snowballing method. Overall, five samples: three commercial poultry (D1, D2, D3), one commercial rabbit-specific (D4), and one on-farm mixed feed (D5), were collected and analyzed for proximate, fiber fractions, minerals and anti-nutritional factors contents. Descriptive statistics, one-way analysis of variance at 0.1% level of significance and Duncan Multiple Range Test in SPSS data analysis software were used to analyze data. Results indicate percent dry matter, crude protein, ether extract, crude fiber, ash, nitrogen free extract, organic matter and metabolizable energy (kcal/kg) ranged from 91.90–90.97, 18.03–16.64, 4.05–3.55, 9.67–5.55, 7.13–5.97, 58.87–54.20, 85.94–84.24, 3014.80–2813.30, respectively. Minerals (mg/kg) ranged from 0.402–0.385 (sodium), 0.626–0.612 (calcium), 0.962–0.947 (potassium), 0.539–0.521 (phosphorus), 0.346–0.321 (magnesium), 48.15–46.75 (iron), 5.53–5.37 (copper), 61.87–60.52 (zinc), 4.86–4.48 (manganese) and 0.089–0.076 (selenium). Percent neutral detergent fiber, acid detergent fiber, acid detergent lignin, hemicellulose and cellulose ranged from 44.87–31.27, 33.05–19.66, 7.13–3.24, 13.0–7.46, 25.92–16.16, respectively. Trypsin inhibitors (mg/g) and percent tannins, phytate, oxalate, saponins and alkaloid ranged from 2.58–2.19, 0.0046–0.0030, 0.409–0.386, 0.292–0.269, 0.402–0.367 and 0.596–0.543, respectively. All feeds may supply enough proximate components to rabbits, except crude fiber. Actively reproducing rabbits fed those feeds may not cover their needs for calcium, phosphorus, iron, zinc, manganese, lysine, potassium, magnesium, copper, acid detergent fiber, neutral detergent fiber, hemicellulose and cellulose. Only acid detergent lignin contents of D5 and D4 were sufficient for rabbit needs. D5 followed by D4 may be fed sole to rabbits, if fortified, especially, with dietary fiber from sources like forages. There is need in Nigeria, needs to produce more commercial rabbit-specific concentrate feeds, that meet rabbit nutrient requirements.