ABSTRACT
A 30-week experiment was conducted to investigate the effect of dietary supplementation of 2 varieties of cassava root meal (CRM) with various additives on performance characteristics of laying birds and the quality of eggs laid. Two hundred and forty 21-week-old (Isa Brown®â³ strain) laying birds were allotted to 8 dietary treatments in a 2 × 4 factorial arrangement of white (TME 419) and yellow (ITA/IBD/1368) CRM supplemented with no additive, amino acids (methionine and lysine), enzyme, and amino acids + enzyme (AA + Enz). The experiment was partitioned in 3 phases: 0-10 weeks, 11-20 weeks, and 21-30 weeks in lay. Variety effect showed improved (p < 0.05) egg production in layers fed with yellow cassava than those fed the white variety. Supplementing yellow cassava root meal (YCRM) and white cassava root meal (WCRM) with AA + Enz from 0 to 10weeks in lay and 11 to 30weeks in lay, respectively, resulted in superior egg production performance at a reduced cost. Feeding the layers with diets containing the two varieties of cassava, with or without additives at the three phases of lay, did not compromise the quality of eggs produced and YCRM did not improve the egg yolk colour. It was concluded that egg production was improved by diets containing YCRM at the 3 phases of lay, and WCRM supplemented with AA + Enz improved egg production only from 11 weeks in lay. The 2 varieties of cassava root meal and the various additives used did not affect the quality of the eggs laid by the layers.
Subject(s)
Manihot , Animal Feed/analysis , Animals , Chickens , Color , Diet/veterinary , Dietary Supplements , Eggs , Oviposition , OvumABSTRACT
Yam (Dioscorea spp) is an essential tuber crop for hundreds of millions of people in many African, Asian and South American countries. Considering in particular Southwest Nigeria, chips, flakes and flours are amongst the most common shelf-stable traditionally-processed yam products. This paper reports a systematic study on the proximate (moisture, protein, carbohydrate, fibre, fat, ash and gross energy) and mineral composition of these three food commodities sold in Nigerian markets. Results showed no significant differences in the moisture, crude protein and fibre content of all samples (10.0-12.3, 2.7-4.3 and 1.3-2.0 wt%, respectively). Gross energy was also comparable for all yam derived food items (between 3300 and 3507 kcal/kg), contradicting the common belief that yam flakes have lower nutritional value than chips and flours. Considering the mineral composition, Ca, Mg, P and K were the predominant macronutrients. Micronutrients such as Zn, Co, Mn and Cu were also detected. Significant differences existed between products, and their various sources (markets). Principal component analysis showed a direct correlation between ash content of the samples and the assessed macronutrients, irrespective of the market, or the seller of the commodities. This study confirmed that yam derived food stuffs have an adequate nutritional composition, irrespective of their form and/or origin.
ABSTRACT
Benniseed and bambara groundnut seeds were roasted at 80 and 120°C for 10-60min. For both flours, the effects of roasting temperature and time on selected functional properties and chemical composition were determined, as were the effects of pH on the emulsification capacity and nitrogen solubility. The chemical constituents of the raw flours were present at higher concentrations than those of the roasted flours except for fat and ash. Protein concentrates of both flours contained 80.5-81.5% crude protein as the major constituent. Nitrogen solubility was lowest at pH 4.0 for raw and roasted benniseed flour and pH 5.0 for raw and roasted bambara groundnut flour. Roasting generally lowered the nitrogen solubility and increased the water and oil absorption capacities while decreasing the foaming capacity and emulsification capacity of both flours.
ABSTRACT
The potential of activated charcoal in the purification of fungal glucoamylase was investigated. Various concentrations of activated charcoal (1-4% w/v) were used to concentrate crude glucoamylase from Rhizopus oligosporus at different temperature values (30-50°C). Effects of pH (3.0-6.0) and contact time (0-60 min) on enzyme purification were also monitored. Activated charcoal (3% w/v) gave a 16-fold purification in a single-step purification at 50°C for 20 min and pH 5.5. The result of SDS-PAGE analysis of purified glucoamylase showed two major protein bands with corresponding molecular weight of 36 kDa and 50 kDa. The method is inexpensive, rapid, and simple which could facilitate downstream processing of industrial enzyme.