Effects of 5-hour wetting of sun-dried cassava tuber meal on the HCN content and dietary value of the meal for young broiler chicks

Résumé

The efficacy of wetting sun-dried cassava tuber meal as a method of reducing its hydrocyanide (HCN) content and improving its nutritive value for broilers was investigated. Cassava tubers were peeled, chopped into pieces, sun dried and then milled. Part of the sun-dried cassava tuber meal was soaked in water at the rate of 5 parts of water to 4 parts of the meal, thinly spread on the floor for 5 hours and then taken out and spread by the side of the tarred road and sun-dried again. The raw cassava tuber meal (RCTM), sun-dried cassava tuber meal (SCTM) and wetted sun-dried cassava tuber meal (WSCTM) were analysed for cyanide conteni. Five diets were made such that dier / (control) contained no cassava tuber meal; in diets 2 and 3, 75% of the maize in diet I was replaced with SCTM and WSCTM, respectively, while in diets 4 and 5, 100% of the maize was replaced with SCTM and WSCTM, respectively. Each diet was fed to a group of 30 one-week old broiler chicks for 4 weeks. Blood was collected from the birds at the end of the feeding trial and haematological constituents determined. RCTM contained 800ppm HCN, SCTM contained 50ppm and WSCTM contained 10ppm. At 100% replacement of dietary maize with SCTM, growth performance of the birds was significantly (P <0.05) depressed. HB, PCV, RBC and WBC were also depressed at that level. Wetting sun-dried cassava tuber meal appeared to be a simple and effective way of processing cassava for use as energy feed for broiler production.