Effects of dried rice distillersʹ and grain supplementation on the performance of lactating cows

The aim of this study was to evaluate the nutritive value of dried rice distillersʹ grain (DRDG) as part of the feed concentrate for lactating cows. Twenty-four lactating Holstein cows that were in early lactation, with an average live-weight of 650 kg and producing 29 kg milk daily, were selected. The cows were then divided into three different groups according to milk yield and number of lactations. The treatment involved various levels of DRDG in the diets. The experimental diets were formulated into three iso-nitrogens and iso-energetic diets that included 0, 10, or 20% DRDG in the diet, respectively. After one week of adaptation, the experimental feeding period began, lasting three weeks. For the purpose of promoting palatability, molasses were added to all diets after the first four weeks of feeding. Three cannulated cows were examined in order to investigate the effects of DRDG supplementation on ruminal fermentation. sults indicated that milk yield and 4% fat-corrected milk for the control and the 10% DRDG groups were higher than the 20% DRDG group (p<0.05). Daily dry matter intake also showed a similar trend (p<0.05) except during the first month of feeding, when the daily dry matter intake of the 10% DRDG group was higher than the 20% groups (p<0.05) (without the molasses addition). With respect to milk composition (milk fat and nonfat solid), the 20% DRDG group demonstrated with lower milk fat and nonfat solids than the other two groups (p<0.05). The 20% DRDG group was lower in milk protein than the 10% DRDG group, but was no different from the control group (p>0.05). During the experimental period, body weight change and serum urea-nitrogen concentration were no different among the treatment groups (p>0.05). The milk urea nitrogen concentration for the 20% DRDG group was higher than the other two groups (p<0.05). Ruminal pH value and concentration of ruminal ammonia nitrogen were not significantly influenced by the inclusion of DRDG. Total volatile fatty acids and the acetic-to-propionic acid ratio, however, were significantly lower for the cows treated with 20% DRDG than the other two groups (p<0.05).