Validation of a novel timed artificial insemination protocol in beef cows with a functional corpus luteum detected by ultrasonography.

This study aimed to clarify the feasibility of a novel timed artificial insemination (TAI) protocol using ultrasonography, and to determine the associations between the ovarian component and fertility. In Experiment 1, 272 Japanese Black cows with a corpus luteum (CL) ≥ 18 mm in diameter were divided randomly into either the TRT group (134 cows that were administered gonadotropin-releasing hormone [GnRH] 56 h [day 2] after prostaglandin F2α [PGF] administration [day 0], followed by TAI 16-20 h later) or the CN-1 group (138 cows that were administered PGF followed by AI after estrus detection). In addition, the CN-2 group was designated for 306 cows given PGF and inseminated after estrus detection in the past two years at the same farms. In Experiment 2, 38 cows had the same treatment as the TRT group, and the sizes of follicles and CL were video-recorded on days 0 and 2. In Experiment 1, the AI and ovulation synchronization rates were higher in the TRT group than those in the CN-1 group (100 vs. 87.0% and 89.2 vs. 33.3%, respectively) (P < 0.01). The pregnancy rate in the TRT group (60.4%) was higher than that in the CN-2 group (45.1%) (P < 0.05). In Experiment 2, cows with a larger CL diameter and greater CL volume on day 0 had a higher pregnancy outcome (P < 0.05). In conclusion, this protocol was effective for improving pregnancy rates in beef herds, and fertility was associated with the CL size at the time of PGF administration.

Evaluation of anti-Müllerian hormone in a dog with a Sertoli cell tumour.

BACKGROUND: Testicular tumours are common in elderly male dogs, and Sertoli cell tumours (SCTs) are among the most common. An increase in blood estradiol concentration is often seen in canine SCTs, but such measurements do not necessarily correlate with the clinical signs. CASE REPORT: A 6-year-old male Pembroke Welsh corgi was referred for nonpruritic alopecia. Clinical examination revealed cryptorchidism of the right testicle, and blood tests showed an increased estradiol concentration. The cryptorchid testis was removed by laparotomy, and SCT was diagnosed histologically. An enzyme-linked immunosorbent assay kit designed to measure human anti-Müllerian hormone (AMH) revealed a very high preoperative serum AMH concentration, which decreased after surgery. The serum AMH concentrations of two intact healthy control male dogs were lower than that of the dog with the SCT before treatment but higher than thoseof two healthy castrated male dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Canine serum AMH concentrations, as measured by a human AMH enzyme-linked immunosorbent assay, may be useful as a marker for canine SCT.

Nectin4 is an epithelial cell receptor for canine distemper virus and involved in neurovirulence.

Canine distemper virus (CDV) uses signaling lymphocyte activation molecule (SLAM), expressed on immune cells, as a receptor. However, epithelial and neural cells are also affected by CDV in vivo. Wild-type CDV strains showed efficient replication with syncytia in Vero cells expressing dog nectin4, and the infection was blocked by an anti-nectin4 antibody. In dogs with distemper, CDV antigen was preferentially detected in nectin4-positive neurons and epithelial cells, suggesting that nectin4 is an epithelial cell receptor for CDV and also involved in its neurovirulence.

Detection of Mycoplasma wenyonii and "Candidatus Mycoplasma haemobos" from Japanese Black breeding cows in Kyushu and Okinawa region, southern part of Japan.

This study aimed to elucidate the epidemiological status of hemoplasma infection and investigate the interaction between Theileria orientalis and hemoplasmas in Japanese Black breeding cows raised in the Kyushu and Okinawa regions. Blood samples were collected from 400 cows from 80 different farms in eight prefectures (five samples per farm and 10 farms per prefecture). Mycoplasma wenyonii (Mw), "Candidatus Mycoplasma haemobos" (CMh), and T. orientalis were examined by polymerase chain reaction (PCR) assay using whole blood samples. PCR results showed that 91.5% (366/400) of cows were positive for bovine hemoplasma: 40.3% were infected with Mw only, 9.5% with CMh only, and 41.8% with both species. T. orientalis was detected in 36% (144/400) of cows. The infection rate of T. orientalis was higher in the grazing group (P<0.001) than in the housed group, while the rate of CMh infection was higher (P<0.05) in the housed group than in the grazing group, suggesting that not only the tick but also other arthropod vectors may contribute to hemoplasma transmission. Although the cows with hemoplasma dual infection showed higher (P<0.05) white blood cell counts compared with hemoplasma-negative cows, there was no difference in hematologic parameters related to the anemia between the hemoplasma-positive and -negative animals. This may indicate that Japanese Black cattle could have resistance to the anemia caused by infection with hemoplasma.

Effect of sugar supplementation on rumen protozoa profile and papillae development in retarded growth calves.

The effect of sugar supplementation with 1 g/kg BW twice a week for eight weeks on rumen protozoa was determined in ten retarded growth calves. Rumen juice was sampled by abdominal paracentesis during the experiment. Papillae development of rumens excised by experimental laparotomy was macro- and micromorphologically determined before and after sugar supplementation in a selected calf. The numbers of Entodinium, Isotricha, Dasytricha and Epidinium protozoa increased by 3 to 12 folds after 1-3 wk of supplementation and subsequently decreased. The heights of the rumen papillae after sugar supplementation showed marked development compared with before supplementation (Post vs. Pre: 4.44 ± 0.43 vs. 1.36 ± 0.24 mm). Sugar supplementation accommodates the rumen protozoa profile and stimulates papillae development in retarded growth calves.

Effects of live yeast supplementation on serum oxidative stress biomarkers and lactation performance in dairy cows during summer.

This study aimed to evaluate the effects of live yeast (Saccharomyces cerevisiae) (LY) supplementation on serum oxidative stress biomarkers, antioxidant vitamin levels, and lactation performance in dairy cows during summer. A total of 16 lactating cows weighing 707.5 ± 13.1 kg (mean ± standard error) were enrolled and randomly assigned to either supplemented (n=8) or control group (n=8). In the supplemented group, the cows were administered with LY product at 10 g/day per cow from mid-July to mid-September for 8 weeks. The serum levels of derivatives of reactive oxygen metabolites in the supplemented group were lower (P<0.05) at week 6. The serum retinol and blood glucose concentrations in the supplemented group were higher (P<0.01) at week 8. LY supplementation did not affect physiological responses, such as rectal temperature, respiratory rate, protein and cholesterol metabolism, and lactation performance. During the study period, daily average milk yield decreased in both groups. The reduction rates of milk yield in the supplemented and control groups were 17.6 and 20.0%, respectively. These results suggest that LY supplementation may reduce oxidative stress and improve carbohydrate metabolism in lactating dairy cows during summer.

Seasonal changes in serum oxidative stress biomarkers in dairy and beef cows in a daytime grazing system.

This study aims to evaluate the oxidative stress during hot summer season using serum oxidative stress biomarkers and elucidate the effects of serum antioxidant vitamin levels in dairy and beef cows in a daytime grazing system. Blood samples were collected once a month from eight Holstein Friesian (HF) and 10 Japanese Black (JB) cows from November 2013 to October 2014. Serum values of derivatives of reactive oxygen metabolites (d-ROMs) tended to be higher in March in both breeds and those in HF cows were kept at higher (P<0.001) levels than those in JB cows during the study period. Serum levels of biological antioxidant potential (BAP) in both breeds were maintained at almost the same values during study period. The OSI [(d-ROMs/BAP) × 100] values in both breeds showed similar seasonal changes, i. e. increase from December to March and decrease from March to August or September. In addition, the OSI values in HF cows were kept at higher (P<0.01) levels than those in JB cows during the study period. Serum concentrations of α-tocopherol, ß-carotene, blood urea nitrogen and total cholesterol showed similar seasonal changes in both breeds, low in the winter and high from spring to summer, which may be attributed to the pasture grass intake. Opposite changes in OSI values and serum concentrations of α-tocopherol and ß-carotene indicated that antioxidant vitamin levels could affect oxidative stress status.

Relationship between plasma vitamin C and serum diagnostic biochemical markers in lactating cows.

We investigated the relationship between plasma vitamin C concentration and serum levels of some diagnostic biochemical markers in 118 lactating Holstein cows. Blood sample was collected once from each cow and we measured the plasma vitamin C concentration and the serum levels of glucose, beta-hydroxybutyrate, free fatty acids, triacylglycerol, total cholesterol, albumin, total bilirubin, alkaline phosphatase, aspartate aminotransferase and gamma-glutamyltransferase. The regression of plasma vitamin C with each serum diagnostic biochemical marker indicated that the vitamin C concentration significantly decreased as glucose, alkaline phosphatase or aspartate aminotransferase level increased and as total cholesterol or albumin concentration decreased. Furthermore, the plasma vitamin C concentration was significantly lower in the cows showing that each of these marker levels was out of its reference interval than in the cows showing that the marker level was within its reference interval. The significant correlations were observed among total cholesterol, albumin, alkaline phosphatase and aspartate aminotransferase levels, to which the glucose concentration was not related. These results showed that the plasma vitamin C concentration was low in the cows that had concurrently low levels of total cholesterol and albumin, and high levels of alkaline phosphatase and aspartate aminotransferase. Therefore, a hepatic malfunction possibly decreases plasma vitamin C concentration through suppressing vitamin C production. On the other hand, the high level of glucose possibly decreases plasma vitamin C concentration through suppressing vitamin C recycling.

In vitro synergistic activities of cefazolin and nisin A against mastitis pathogens.

First-generation cephalosporins such as cefazolin (CEZ) have been widely used for mastitis treatment in dairy cattle. However, the use of antibiotics results in the presence of antibiotic residues in milk, which is used for human consumption. Nisin A, a bacteriocin produced by Lactococcus lactis, has been used as a broad-spectrum food preservative for over 50 years. Therefore, a combination of CEZ and nisin A might provide an extended activity spectrum against mastitis pathogens and reduce the antibiotic dose for mastitis treatment. This study aimed to evaluate the combined effect of CEZ and nisin A against mastitis pathogens using the checkerboard and time-kill assays. In the checkerboard assay, the CEZ-nisin A combination exhibited a synergistic effect against Staphylococcus aureus (n=20/20) and Enterococcus faecalis (n=13/18), and meanwhile exhibited a mostly additive effect against Staphylococcus intermedius (n=12/20), Streptococcus agalactiae (n=10/10), Streptococcus dysgalactiae (n=18/18), and Escherichia coli (n=14/18). There were no indifferent or antagonistic effects between CEZ and nisin A. In the time-kill assay, the CEZ-nisin A combination at 0.5 × or 1 × minimum inhibitory concentration exhibited synergistic reduction of bacterial growth by over 3 log10 colony forming units per ml relative to that observed with either antimicrobial substance alone. These results suggest that the CEZ-nisin A combination can be used for developing an intramammary infusion for mastitis treatment, with lower antibiotic concentrations than normal.

Histopathological changes in the pancreas of cattle with abdominal fat necrosis.

The association between pancreatic disorder and abdominal fat necrosis in cattle remains unclear. The pancreases of 29 slaughtered cattle with or without fat necrosis were collected to investigate pathological changes. Japanese Black (JB) cattle were classified into the FN group (with abdominal fat necrosis; n=9) and N group (without fat necrosis; n=5). The pancreases were also collected from 15 Holstein Friesian (HF) cows. All JB cattle showed high body condition scores. Regarding the pathological findings, fatty pancreas which involves adipocyte infiltration into the pancreas and fat necrosis (saponification) were observed in 25 and 27 cases, respectively. Immunohistochemical staining with anti-Iba-1 antibody showed large numbers of macrophages surrounding the saponified fat in the pancreas. CD3-positive T cells were significantly more common in the pancreas of both the FN and N groups compared with the HF group (P<0.05). Furthermore, fibrosis in the pancreas exhibited a correlative tendency with the formation of necrotic fat mass in the peritoneal cavity (P<0.1). These results indicate that obesity leads to increased severity of pancreatic disorder, including fatty pancreas and pancreatitis. The pathological lesions in the pancreas may play a key role in abdominal fat necrosis through the inflammatory process.

The association of culling and death rate within 30 days after calving with productivity or reproductive performance in dairy herds in Fukuoka, Southern Japan.

The incidence of peripartum disorders in dairy herds negatively influences productivity and reproductive performance. Concrete data from local areas are helpful for explaining the importance of peripartum management to dairy farmers. This study was conducted to clarify the association of culling and death rate within 30 days after calving with productivity or reproductive performance in 179 dairy herds in Fukuoka, Southern Japan. A database was compiled from the records of the Livestock Improvement Association of Japan, the Dairy Cooperative Association and the Federation of Agricultural Mutual Relief Association. In this study, we created a comprehensive database of dairy farm production data for epidemiological analysis and used a general linear mixed model to analyze the association of culling and death rate within 30 days after calving with milk production or reproductive performance. The database can be used to describe, analyze and predict the risk of production. A cross-sectional analysis with contrasts was applied to investigate the association of cows served by AI/all cows, pregnant cows/cows served by AI, days open, milk yield and somatic cell counts with culling and death rate within 30 days after calving. The days open value significantly increased with increasing rate of culling and death within 30 days after calving (P for trend <0.001). No significant differences were found for the other comparisons. Our data suggest that proper feeding and management in the dry period may lead to improved postpartum reproductive performance in this dairy cow cohort.

Effects of ozonated autohemotherapy on the antioxidant capacity of Thoroughbred horses.

The performance of horses undergoing regular intense exercise is adversely affected by oxidative stress. Thus, it is important to increase antioxidant production in horses in order to reduce oxidative stress. Ozonated autohemotherapy (OAHT) reportedly promotes antioxidant production. This study aimed to evaluate the effects of OAHT on antioxidant capacity. Ten Thoroughbred horses were used in this study. After the OAHT, we collected serum samples and measured biological antioxidant potential (BAP). We found that BAP began to increase after the OAHT and was significantly higher in the OAHT group than at 3 (P<0.01) and 7 days (P<0.05) after OAHT than in the control group at 3 and 7 days after starting collection of blood samples. Therefore, it was shown that OAHT improved the antioxidant capacity of the horses.

Surgical management of combined hydrocephalus, syringohydromyelia, and ventricular cyst in a dog.

Combined hydrocephalus, syringohydromyelia, and a ventricular cyst were found by magnetic resonance imaging in a 7-month-old, male miniature dachshund with gait abnormalities and altered mentation. Clinical signs did not improve with prednisone therapy. Ventriculoperitoneal shunting improved the clinical signs and anatomical abnormalities. Repeated operations were needed to replace the ventricular drainage tube at 3 and 31 months after the first surgery. The animal died suddenly with severe tonic-clonic, generalized seizures 3 weeks after the third operation. Ventriculoperitoneal shunting may be a viable treatment for syringohydromyelia associated with hydrocephalus.

Seasonal changes in serum vitamin A, vitamin E and beta-carotene concentrations in Japanese Black breeding cattle in Hyogo prefecture.

The influence of the season on serum vitamin A, E and beta-carotene concentrations was studied in Japanese Black breeding cattle. Blood samples were collected from 13 cows once a month for a year to determine the serum vitamin concentrations. Mean serum concentrations (+/- SE) of retinol, alpha-tocopherol and beta-carotene were 21.3 +/- 0.5 microg/dl (range 9.9 to 44.9), 215.9 +/- 8.0 microg/dl (range 59.7 to 551.6) and 67.3 +/- 5.1 microg/dl (range 10.6 to 425.2), respectively. All these concentrations were lower than the recommended levels. Serum retinol and alpha-tocopherol concentrations in summer were lower than those in winter. These results suggest that the vitamin A, E and beta-carotene status of Japanese Black breeding cows is inadequate, and feeding high quality forages or dietary vitamin supplementation during summer should be recommended.

Accumulation of xanthophylls from the phaffia yeast (Xanthophyllomyces dendrorhrous) in calves.

An investigation into the absorption and accumulation of carotenoids from phaffia yeast in two to three-week-old calves was carried out. Carotenoid contents of the control cattle (n=1) were 615.0 ng/g in the liver, 263.7 ng/g in the duodenum, 218.0 ng/g in the pancreas, 170.0 ng/g in the blood, 140.3 ng/g in the jejunum, 115.0 ng/g in the spleen. Among the accumulated carotenoids, ß-carotene was presented as a major component (86.0 to 94.3%) along with lutein (5.7 to 14.0%) as a minor component. On the other hand, carotenoid contents in phaffia yeast-supplemented (5 g/day for one month) calves (n=3) were 4 to 10 times higher than those of the control calf. Carotenoid contents of phaffia yeast-supplemented calves were 2570.1±782 ng/g in the liver, 1806.6±1064 ng/g in the pancreas, 1648.4±630.2 ng/g in the spleen, and 1255.9±300.2 ng/g in the blood. In addition to ß-carotene, keto-carotenoids from phaffia yeast, echinenone, (3R)-3-hydroxyechinenone, and (3R,3'R)-astaxanthin, were accumulated in all organs of phaffia yeast-supplemented calves. ß-Carotene and (3R)-3-hydroxyechinenone were present as major carotenoids followed by echinenone. However, (3R,3'R)-astaxanthin, which was the major carotenoid in phaffia yeast, was found to be a minor carotenoid in calves. This indicated that calves well absorbed fewer polar xanthophylls, echinenone and (3R)-3-hydroxyechinenone compared to the polar xanthophyll, astaxanthin.

Rumen ciliates from Tanzanian short horn zebu cattle, Bos taurus indicus, and the infraciliature of Entodinium palmare n.sp. and Enoploplastron stokyi (Buisson, 1924).

Rumen ciliates of ten Tanzanian short horn zebu cattle were examined. A total of 15 genera and 46 species were identified, including a new Entodinium species. The ciliate density was 22.2 x 10(4)ml(-1). The number of species per host and the diversity index showed high values, 33.8 and 2.80, respectively. Rumen ciliates had a low percentage composition of the genus Entodinium (7.0-25.0%) and a slightly higher percentage composition of the genera, Eudiplodinium (19.3%), Diplodinium (14.1%), and Ostracodinium (13.1%). Entodinium palmare n.sp., Eudiplodinium kenyensis, and Enoploplastron stokyi were found in all cattle examined. The former two species have been found only in African zebu cattle. Entodinium palmare n. sp. has a characteristic right surface of the body like the "palm of a hand" because of the concave part on the postero-dorsal part of the body, and has the same pattern of infraciliary bands as in other Entodinium species. Enoploplastron stokyi has a characteristic pattern of infraciliary bands analogous to those of Epidinium ecaudatum and Ostracodinium mammosum; with the right side of the adoral polybrachykinety gradually tapering and a slender short vestibular polybrachykinety.