Abstract
Feeding of cedar raw sawdust as main roughage to breeding Japanese Black cattle is gradually spreading in Miyazaki prefecture, Japan. In general, this feeding method has been done by a mixture of sawdust and concentrate. In addition, a small amount of forage usually offers to animals in the afternoon. We investigated the feeding effect of particle size of sawdust on eating and ruminating patterns, Roughage Value Index (RVI), rumen fluid characteristics and blood serum composition. Cattle were given 2 different rations, (1) a mixture of normal size sawdust (without sieving) with concentrate, and a small amount (448 g DM/head) of rhodesgrass hay (control), (2) a mixture of small size sawdust (through a 5 mm sieve) with concentrate, and a small amount (448 g DM/head) of rhodesgrass hay (treatment).
Results showed that total rumination time, number of rumination, average ruminating time, elapsed time (from the end of eating time to the beginning of rumination) and RVI were not affected (P>0.05) by the feeding of rations. In rumen fluid characteristics, pH value was more than 6.5 in both control and treatment rations. The protozoa numbers of feeding of both control and treatment rations were lower than the normal level (10-100×104/dl of ruminal fluid). In blood composition, the values of some parameters were not within the standard level, but did not get off remarkably.
In conclusion, particle size of sawdust may not be a matter of concern, if animals are introduced to the sawdust with concentrate and a small amount of forage.
