The purpose of this study was to examine the effect of feeding seaweed (Ascophyllum nodosum) on the activating intestinal immune system of Japanese Black cow. We studied the influence of feeding seaweed on fecal immunoglobulin A (IgA), volatile fatty acid (VFA) concentration, and fecal characteristics of Japanese Black cow. The examination was carried out by a 2×2 cross-over design with arranging two cattle each treatment group (SW ; seaweed fed group, C ; seaweed non-fed group). Measuring items were as follows : fecal score, pH, water content, IgA and VFA concentrations. Difference on day1 to day10 of fecal IgA concentration was significantly higher in the SW group compared with C group (P<0.05). There was no significant difference in fecal pH and VFA concentration between the groups. There was no correlation between fecal IgA and VFA concentrations. These results indicated that intake of seaweed improved intestinal immune system of Japanese Black cow. On the other hand, we considered that the intestinal microbiota does not appear to be involved in this effect.

We examined the effect of the use of polished rice or the combination of polished rice and rice bran in feed on pork quality. Thirty-two Duroc gilts were assigned to 4 treatment groups. The average initial bodyweight of the pigs was 70kg. The treatments were as follows ; 70% corn diet as the control ; a polished rice (PR) treatment replacing corn ; polished rice+10% rice bran (60% PR+10% RB) treatment ; and polished rice+20% rice bran (50%PR+20% RB). All pigs were fed these diets until their live weight reached at 115kg. The L* value of the inner layer of backfat in the PR group was higher than that in the control. There were no differences in the L* value between the control and PR+10% and PR+20% groups. The percentage of oleic acid in the inner layer of backfat of the PR group was higher than that for the control. However, as the ratio of rice bran in diet increased, the percentage of oleic acid decreased to the same level as that in the control. Linoleic acid and α-linoleic acid levels in the PR group were lower than those in the control and increased to a level equivalent to or greater than that in the control as the ratio of rice bran in diet increased. From these results, the 70% polished rice diet increased L* value and oleic acid in the inner layer of backfat, and decreased polyunsaturated fatty acid levels. Higher rice bran with lower polished rice content in the diet reduced the difference in fatty acid composition between the control and PR groups.

In this study, the fatty acid compositions of eight muscles from Japanese Black steers were estimated by measuring impedance with touch type electrodes. Impedance was measured in samples prepared from the eight muscles and from subcutaneous fat found between the 6th and 7th ribs of Japanese Black steer carcasses (n＝11) ; the measurements were made at 1Hz, 120Hz, and 100kHz with an LCR meter equipped with touch type electrodes. Fatty acid compositions of the samples were analyzed by gas chromatography. For M. longissimus thoracis, significant correlations were found between the oleic acid percentage and impedance at all frequencies. This result suggests that it is possible to estimate oleic acid percentage of M. longissimus thoracis by measuring impedance at a range of frequencies. A significant correlation was present between oleic acid percentage of subcutaneous fat and impedance at 1Hz. The oleic acid percentages in M. longissimus thoracis and subcutaneous fat were also significantly correlated. These results suggest that it is possible to indirectly estimate oleic acid percentage of M. longissimus thoracis by measuring impedance of subcutaneous fat at 1Hz.

In order to clarify the calf growth and reproductive performance of the cows in the year-round grazing system for cows with their calves in a cold region, a survey was conducted at K farm, where practiced the year-round grazing system for cows with their calves of Japanese Black in the northern Tohoku region. A total of 24 calves were weighed monthly for two years. The reproductive performance of cows was analyzed by browsing the reproductive records. The pasture was highly dominated by Kentucky bluegrass (Poa pratensis L.). The calves were supplemented with grass silage and concentrate diet in summer as well as corn silage in winter. The average daily gain in calves up to 9 months of age was 1.07kg/day for males and 0.94kg/day for females. For calves born in winter (from December to February), the average daily gain was 1.13kg/day for males and 0.93kg/day for females. The mean and median calving intervals were 410 and 384 days, respectively. In the year-round grazing system for cows with their calves in the northern Tohoku region, the growth performance of calves was enough, and the reproductive performance of cows was not inferior to the national average.