Growth, nutrient digestibility, ileal digesta viscosity, and energy metabolizability of growing turkeys fed diets containing malted sorghum sprouts supplemented with enzyme or yeast
Malted sorghum sprouts (MSP) produced as a result of incomplete germination of sorghum (referred to as malting) is a cheap alternative feedstuff. This malting process is commonly used in breweries and food processing companies for the manufacture of drinks and beverages, etc. (Briggs et al., 1991). Commercial malting of sorghum with an output estimated to the tune of 200 000 metric tons of malted and unmalted extracts per annum was reported by Ikediobi (1989). This has led to the production of large quantities of MSP.
Nutritional evaluation of MSP showed that it contained 226, 224, 33, and 522 g/kg (DM basis) of crude protein, neutral detergent fibre (NDF), ether extract, and nitrogen‐free extract respectively (Aning et al., 1998). Oke (2010) reported crude protein, ether extract, ash, NDF, acid detergent fibre (NDF), and acid detergent lignin (ADL) values of 164, 38, 63, 217, 147, and 10 g/kg, respectively, for MSP. Successful utilization of MSP up to 10% inclusion in growing pullets has been reported in previous studies (Fafiolu et al., 2006). However, the nutritional potentials of MSP as feedstuff for poultry are limited due to the constituent fibre fractions (NDF and ADF), hydrocyanide, and tannin contents (Oduguwa et al., 2001). Residues of tannin and arabinoxylan have been reported to reduce nutrient digestibility and growth of poultry (Balogun et al., 2005). Recent studies have shown that dietary supplementation with fibre‐degrading enzymes improved pre‐caecal nitrogen digestibility, apparent metabolizable energy (AME) (Cowieson et al., 2003), digestion of dietary starch, fibre, protein, and lipid in poultry (Choct et al., 1996). Similarly, yeast and its extracts have been reported to improve growth, nutrient digestibility, and stimulate birds' immune systems (Abel and Czop, 1992). In this study, diets containing 0, 50, or 100 g/kg MSP in which supplements of either enzyme or yeast have been incorporated were fed to growing turkeys. The performance characteristics, nutrient digestibility, viscosity of ileal digesta, and energy metabolizability were used as criteria of response.