Rice gluten meal as an alternative by-product feed for growing dairy calves.

Abstract

This experiment aimed at studying the nutritional characteristics and feeding value of rice gluten meal (RGM, a wet-milling by-product of rice) in growing dairy calves. RGM contained 464g/kg of crude protein with 821 and 196g/kg nitrogen (N) of borate-phosphate insoluble N and acid detergent insoluble N, respectively, which were higher (P < 0.05) than groundnut cake (GNC). In vitro gas production, organic matter digestibility and energy values were comparable between RGM and GNC. For in vivo trial, 18 Karan-Fries calves (6-12months) were randomly assigned into three groups based on comparable body weight and age. The first group (GP-I) was fed concentrate mixture containing mainly GNC as protein source, whilst it was replaced by RGM up to 50 and 75% on N basis, in second (GP-II) and third (GP-III) groups, respectively. Thus, RGM constituted 140 and 210g/kg of concentrate mixture of GP-II and GP-III, respectively. In addition, all animals were offered chopped green maize and wheat straw for the whole experimental period of 90days. Results revealed that there was no difference in intake and digestibility of nutrients, N balance, average daily gain (ADG) and feed efficiency among three groups. Nevertheless, RGM-based diets produced cost-effective ADG than GP-I. Furthermore, experimental calves did not differ in haematological variables like glucose, blood urea N, plasma proteins and non-esterified fatty acids. This study demonstrated that RGM could be incorporated successfully in the concentrate mixture, replacing 75% of GNC without any discernable compromise in the performance of growing calves.