Processed false yam seed meals in broiler chicken diets: effects on feed preference and apparent nutrient digestibility

Abstract

This study evaluated feed preference and apparent nutrient digestibility of a maize-based diet and modified diets containing treated false yam seed meals (TFYSM). False yam seeds were sun-dried (Un_T), or first soaked in water and treated with one of the following: urea (Urea_T), sodium chloride (NaCl_T), sodium hydroxide (NaOH_T), or potassium hydroxide (KOH_T) and blanched. The TFYSM replaced maize (wt/wt) in experimental diets at 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50%, respectively in a feed preference test (experiment 1). In that study, feed preference test was conducted with 6 × 4 broiler chicks aged 21days in a randomized complete design; each level of each TFYSM was fed for 24h and feed intake recorded. In experiment 2 of the study, apparent nutrient digestibility of TFYSM-based diets was evaluated for 15days with 4-week-old chicks allocated to 5 groups of 20 birds which were further subdivided into 5 treatment groups of 4 birds (replicates) using the inclusion levels of 10, 20, 30, 40, and 50% respectively. The preference test data indicated that feed intake was not compromised when maize was substituted by NaCl_T, NaOH_T, Urea_T, and KOH_T FYSM at all levels, and Un_T FYSM up to 5% inclusion. Dry matter digestibility was generally high (> 75%) in all diets except for Un_T. Control diet and NaOH_T diets had similar CP digestibility, but higher than KOH_T diets, while Un_T diets had reduced CP digestibility. Digestibility of NFE ranged from (77.4%) (Un_T) to (93.8%) (KOH_T). Improving apparent nutrient digestibility of FYSM by sequential use of water-based and chemical treatment methods especially NaOH_T or KOH_T offers the potential to use this alternative feedstuff in broiler diets.