It has been reported that cashew nut shell liquid（CNSL） inhibits methane production and enhances propionate production in in vitro and experimental cow studies. The object of this field study was to evaluate the effect of pelleted CNSL on rumen fermentation of Holstein dairy cows. Eight cows between 28 and 80 days postpartum were used and evaluated for ruminal volatile fatty acids（VFA）, ruminal pH, hematology and fecal consistency. Four cows were fed 50 g of CNSL pellets（2.5 g as CNSL） per day for 4 weeks, and the other 4 were untreated as the control group. In the CNSL group, although no changes were seen in hematological parameters and fecal consistency, higher total VFA, acetate and butyrate concentrations and lower ruminal pH were noted after 4 weeks of CNSL feeding compared to the baseline values（p<0.05）. The propionate concentration also increased, but the increase was not statistically significant. The molar ratios of ruminal acetate/propionate/butyrate and acetate/propionate were not significantly different between the two groups. These results suggest that feeding of CNSL pellets may enhance the rumen fermentation of dairy cattle without affecting blood components and fecal consistency.

Porcine epidemic diarrhea（PED）is an acute viral disease characterized by watery diarrhea and high mortality in newborn piglets. Immunohistochemical（IHC）detection of PED virus on the intestinal tissue is effective for the diagnosis of PED. However, IHC diagnosis of PED using routine fixation is time-consuming. We therefore investigated the usefulness of a rapid fixation method and frozen sections using a field sample for faster diagnosis of PED. For rapid fixation, the tissues were fixed in 10% neutral buffered formalin for different time periods and at different temperatures and compared for staining pattern and intensity. For frozen sections, tissues were frozen in hexane at -80℃, sectioned and fixed in formalin-methanol. The sections were then processed by microwave heating for antigen retrieval and immunostained for PED antigens. As a result, the rapid fixation at 40 and 60℃ for 1 h was sufficient for the detection of PED virus. By this rapid fixation method, the results of IHC diagnosis can be obtained by the following day. The cryosections also exhibited specific immunostaining and well-preserved morphology. In conclusion, these rapid fixation and frozen section protocols have a potential use for the rapid diagnosis of PED within a day or two of necropsy.

Theileria orientalis（TO）infection may have a negative effect on the reproductive performance of cattle. In the present study, we investigated the effect of a tick control programme for TO infection on the reproductive performance of Holstein heifers. Grazing heifers on two selected pastures with histories of TO infection in the eastern part of Hokkaido were treated with acaricides for four consecutive years. The animals were categorized into three groups based on their TO infection status determined by a diagnostic PCR assay: negative; negative to positive conversion; and positive.

After the introduction of the programme, the number of animals converting to TO-positive started to decrease, while the overall reproductive performance improved every year．Compared to TO-negative animals, TO-positive animals had a significantly lower red blood cell count（RBC）at the beginning of the grazing season, and animals that converted to TO-positive also showed lower RBC after 2 months of grazing. TO-negative animals showed higher insemination and conception rates than TO-positive animals as well as a shorter time to the first insemination and a higher insemination rate than animals that became TO-positive. Taken together, these findings suggest that tick control measures improve the reproductive performance of grazing heifers in TO endemic regions.

The objective of the study was to investigate the applicability of ultrasound imaging as a diagnostic tool for ovarian status in subestrus, breeding Japanese Black cows. Cows were examined either by rectal palpation or ultrasound, and a PGF_2α analog was administered for induction of estrus, if a functional corpus luteum was confirmed and no reproductive abnormalities that might interfere with the estrus or conception were detected. As a result, the conception rate after single administration of a PGF_2α analog and AI was not significantly different between the ultrasound and rectal palpation groups, but the rate of AI and the response rate to PGF_2α（the number of confirmed conceptions/the number administered） were significantly higher in the ultrasound group（p<0.05）. By season, the rate of AI was stable and remained at around 70% throughout the year in the ultrasound group, but the rectal palpation group had lower AI rates from the summer to the autumn with a statistical significance compared to the ultrasound group in the autumn（p<0.05）. By age（<4, 4-6, 6-8, and >8 years）, the AI rate was significantly higher in 4- to 6-year-old cows in the rectal palpation group than in the ultrasound group（p<0.05）, whereas in cows 8 years of age or older, it was significantly high in the ultrasound group（p<0.01）. The conception rate was numerically higher in the ultrasound group in the summer（p=0.1）and in cows aged 8 years or older（p＝0.06） compared to the other group. In conclusion, ultrasound imaging at the time of administration of PGF_2α to induce estrus in subestrus, breeding Japanese Black cows may improve the treatment outcome particularly in the summer and for older cows with reproductive problems.

A 41-month-old Holstein cow was presented with a chief complaint of astasia. It also had a history of nodular cutaneous lesions of 2 months’ duration. Several alopecic spots and nodular cutaneous masses were observed on the head, neck, shoulder and back. Physical examination revealed enlargement of most of the surface lymph nodes. Masses were also palpated in the pelvic cavity by rectal palpation. Histopathological examination of punch biopsy samples from the skin lesions and fineneedle aspiration smear cytology of the iliac lymph node showed large, atypical round cells. Although lymphocytosis was not noted by hematology, activities of serum total lactate dehydrogenase（LDH）, LDH isozymes and thymidine kinase were elevated. Serum antibody against bovine leukemia virus was negative. The cutaneous form of bovine leukosis was strongly suspected from these findings. Necropsy and histopathological findings confirmed the diagnosis of cutaneous T-cell form bovine leukosis.