Abstract
Four lactating Holstein cows were used in a 2×2 cross over design to determine the effects of feeding total mixed ration (TMR) silage containing 25% of corn grain or 25% of cracked brown rice on dry matter intake (DMI) and milk production (Experiment 1). Then, four lactating Holstein cows were used in a 2×2 cross over design to determine the effects of particle size of brown rice (ground and cracked rice) in TMR silage on DMI and milk production (Experiment 2). In experiment 1, DMI of cows fed TMR silage containing brown rice was tended to increase (P < 0.10) compared with that of corn. Dietary treatment did not affect the milk yield, milk fat, protein and lactose content. Treatment did not affect the apparent dry matter (DM) and crude protein (CP) digestibility. In experiment 2, DMI of experimental cows was not different between treatments. Milk yield of cows fed ground rice was significantly higher (P < 0.05) than that of cows fed cracked rice. The dietary treatment did not affect milk composition. The apparent DM (P < 0.10) and CP (P < 0.05) digestibility of cows fed ground rice was higher than that of cows fed cracked rice. These results indicated that cracked brown rice can be used for lactating dairy cows as substitute for corn grain. The particle size of brown rice has effects on nutrient digestibility and milk yield.
