Hiroki Matsuyama

Effect of replacing corn with brown rice grain in a total mixed ration silage on milk production, ruminal fermentation and nitrogen balance in lactating dairy cows

Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design to determine the effects of substituting corn grain with brown rice (BR) grain in total mixed ration (TMR) silage on milk yield, ruminal fermentation and nitrogen (N) balance. The TMR silages were made from the ensiling of TMR containing (dry matter basis) 50.1% forage in rice silage and corn silage combination, and 49.9% concentrate. The grain portion of the diets contained 31.2% steam-flaked corn, 31.2% steam-flaked BR or an equal mixture of corn and BR. Dietary treatments did not affect dry matter intake, milk yield and milk fat, protein and lactose yields. The ruminal pH and total volatile fatty acid concentrations were not affected by dietary treatment. The urinary N excretion decreased linearly (P < 0.01) in response to increased levels of BR, with no dietary effect on N intake, N secretion in milk and fecal N excretion. Our results indicate that steam-flaked BR is a suitable replacement for steam-flaked corn in dairy cow diets, and that it can be included in rations to a level of at least 31.2% of dry matter without adverse effects on milk production, when cows were fed rice silage and corn silage-based diets.

Feeding value of total mixed ration silage with spent mushroom substrate.

Six wethers were used in a digestibility experiment arranged as replicated 3 x 3 Latin square to evaluate the nutritive value of total mixed ration (TMR) silages that were made from ensiling of TMR containing 0, 6.5 and 13.0% (dry matter basis) of spent mushroom substrate (SMS) for 45 days (treatments denoted as CSMS, LSMS and HSMS, respectively). The amount of SMS replaced the same amount of timothy hay in the respective TMR. All TMR were well preserved as indicated by their low pH, low ammonia-N and high lactic acid contents. Increasing levels of SMS in the TMR silage quadratically reduced (P < 0.05) nutrient digestibility with the exception of ether extract. The difference of total digestible nutrients and digestible energy contents between LSMS and CSMS TMR silage were less than those between LSMS and HSMS. Increasing concentration of SMS in the ration tended to decrease content of total volatile fatty acids in rumen fluid but increased the ratio of acetate to propionate and pH. The study suggests that a SMS level of 6.5% in the diet DM can be recommended for silage based TMR.

Effect of anthocyanin-rich corn silage on digestibility, milk production and plasma enzyme activities in lactating dairy cows.

Anthocyanin in purple corn (Zea mays L.) has been reported to show several functional and biological attributes, displaying antioxidant, antiobesity and antidiabetic effects in monogastric animals. The objective of this study was to investigate the effect of feeding anthocyanin-rich corn (Zea mays L., Choko C922) silage on digestibility, milk production and plasma enzyme activities in lactating dairy cows. The cows were fed diets based on the control corn or the anthocyanin-rich corn silage (AR treatment) in a crossover design. The anthocyanin-rich corn silage-based diet had a lower starch content, nutrient digestibility and total digestible nutrients content when compared to the control diet. The milk yield, lactose and solids-not-fat contents in the AR-treatment cows were lower than in the control cows. The feeding of the anthocyanin-rich corn silage led to a reduction in aspartate aminotransferase (AST) activity and an increase in superoxide dismutase (SOD) activity in the plasma. These data suggest that the anthocyanin-rich corn has a lowering effect on AST activity with concomitant enhancement of SOD activity in lactating dairy cows. However, a new variety of anthocyanin-rich corn with good nutritional value is needed for practical use as a ruminant feed.

Digestibility, ruminal fermentation, nitrogen balance and methane production in Holstein steers fed diets containing soy sauce cake at 10 or 20%

Two feeding trials were performed to evaluate the effect of soy sauce cake (SSC) on digestibility, ruminal fermentation and nitrogen (N) balance as well as methane production in Holstein steers. Six animals received a diet without or with the SSC at 10% (Experiment 1) and 20% (Experiment 2) in a 2 × 2 crossover design with a balance trial and respiratory exchange measurement. The SSC feeding showed a strongly inhibitory effect on methane production when its proportion was elevated up to 20%. The digestibility of nutrients with the 10% SSC treatment was similar to that of the control, whereas that for the 20% SSC treatment was significantly decreased in comparison with the control. The 20% SSC treatment also inhibited ruminal fermentation. A lower N partition to urine and a higher N partition to retention were observed in the animals receiving the 20% SSC treatment. These results suggested that SSC feeding at 20% suppressed methane production and changed the N balance; however, the feeding level of 20% caused deterioration in some productive aspects, such as nutrient digestibility and ruminal fermentation. In addition, a feeding level of SSC at 10% of the diet should be considered a reasonable level in cattle.