Evaluation of site-specific management zones on a farm with 124 contiguous small paddy fields in a multiple-cropping system

The identification of homogeneous management zones (MZs) within a field is a basis for site-specific management (SSM). We assessed the method of defining MZs based on the spatio-temporal homogeneity of six soil properties and above-ground biomass data from paddy rice, winter wheat and soybean over 3 years on a farm with 124 contiguous small paddy fields. The soil data were recorded at 372 soil sampling sites on a rectangular grid over the farm. A non-hierarchical cluster analysis was applied to the soil data and the algorithm grouped the sites into three clusters with similar soil properties. These clusters represent soil fertility and soil drainage. The three clusters were not randomly distributed across the fields, but formed contiguous areas associated with landscape position. This was due to the spatial variation of the soil in the study area. We delineated five MZs based on the spatial structure of the soil heterogeneity of the study area. The validity of the MZs was evaluated using the biomass data from paddy rice, winter wheat and soybean in each MZ; this depended mainly on soil fertility when conditions were dry. When the growing season precipitation was greater than the 10-year average, the biomass of winter wheat and soybean depended on soil drainage. This suggested that the delineation of MZs for site-specific management in fields under a paddy-upland crop rotation system should be based on several soil properties. The biomass data from the three crops over 3 years was not effective for delimiting MZs.     

Immunohistochemical analysis of the distribution of classical swine fever (CSF) viral antigen in boar-pig hybrids and pigs four weeks after infection

We detected the classical swine fever virus (CSFV) antigen in three boar-pig hybrids (hybrids) and three pigs. All animals were experimentally infected with CSFV strain JPN/27/2019 to optimize diagnostic sampling and risk assessment of virus dissemination. Two hybrids died 17- and 19-days post-inoculation (dpi). The other animals were euthanized at 28 dpi. The detection of CSFV antigen at 28 dpi in epithelial cells of the apocrine sweat and sebaceous glands in the skin, salivary glands, mucosal epithelial cells in the rectum, and epithelial cells in the kidney and urinary bladder, suggests that CSFV persists in these tissues and spreads via sweat, saliva, feces, and urine for at least 4 weeks. These findings reveal that hybrids and pigs represent a high risk of virus dissemination four weeks after infection with CSFV strain JPN/27/2019. Prominent CSFV antigens were also detected in hair follicles of the skin. These results suggest that postmortem sampling of animal skin may be effective for CSF diagnosis and can be used to develop a rapid and easy diagnostic method using hair follicles.     

Preservation of feline anti-Toxoplasma gondii antibody activity using blood absorbed on filter paper stored under different conditions

The present study deals with the successful long-term preservation of feline anti-Toxoplasma gondii antibody activity on filter paper strips stored with silica gel. When filter paper strips were kept at 25 degrees C with silica gel, antibody activity in blood samples was preserved for at least six months.     

Breeding season in female cats acclimated under a natural photoperiod and interval until puberty

The breeding season was investigated in 174 female cats that were acclimated under a natural photoperiod, and determined the interval between birth and initial estrus (puberty) was determined in 125 cats. Although the breeding season differed noticeably among individual animals, the mean was 180.4 +/- 3.0 (SE) days between the end of January and the end of July. The interval between birth and first estrus ranged from 181 to 560 days, with a mean of 345.0 +/- 0.9 days. With respect to month of birth, the mean interval was 343.0 +/- 9.5 days in cats born between March and June. Among cats that were born between July and October, the mean intervals were 242.0 +/- 6.3 days in cats that exhibited estrus the year after birth and 519.2 +/- 5.8 days in those that exhibited estrus 2 years after birth.     

The first record of sucking louse, Neohaematopinus callosciuri, infesting pallas squirrels in Japan

A species of sucking louse, Neohaematopinus callosciuri, was found for the first time in Japan. The species was found on an invasive species of squirrel, Pallas squirrel, Callosciurus erythraeus, in the Kamakura district, Kanagawa Prefecture, Japan. A total of 52 lice were obtained from 22 of 104 squirrels captured. The lice were about three times more prevalent in male squirrels than in females and were detected most frequently in the winter. As N. callosciuri has never been reported on wild animals in Japan, this species probably was introduced into Japan along with their host, Pallas squirrels.     

Disappearance of the PHA-E lectin binding site on the surface of ejaculated sperm and sperm capacitation in the dog

Ejaculated semen and cross sections of the cauda epididymides collected from 3 normal dogs were smeared or stamped on glass slides, and the sperm on the slides were stained with 7 different FITC-lectins (Con A, DBA, GS-1, PHA-E, PSA, UEA-1, WGA) to examine the relation between sperm-binding glycoprotein derived from the canine prostate and sperm capacitation. The only lectin that stained the ejaculated sperm but not the cauda epididymal sperm was PHA-E. The sperm ejaculated by 5 other dogs were incubated for 4 hr in fluid flushed from the uterine horns or oviducts of estrous bitches, and then the percentages of actively motile sperm and hyperactivated sperm (HA-sperm) were determined. The percentages of PHA-E-labeled sperm and sperm labeled with fluoresceinated Ca indicator to assess the influx of Ca into the sperm were also evaluated. The mean percentages of actively motile sperm, HA-sperm, and Ca-labeled sperm after 4 hr of incubation in the uterine flush fluid and oviductal flush fluid were significantly higher than in control medium (P<0.05, 0.01), but the mean percentages of PHA-E-labeled sperm were lower (both P<0.01). The percentages of PHA-E-unlabeled sperm correlated with the percentages of both HA-sperm and Ca-labeled sperm (r(2)=0.787 and 0.812, respectively). The results indicate that loss of the glycoprotein secreted by the canine prostate on the sperm surface induces the influx of Ca into the sperm, and then hyperactivation of the sperm.     

Formation of detached tail and coiled tail of sperm in a beagle dog

The right testis and epididymis were excised from a Beagle dog that ejaculated high percentages of sperm with detached tails and with coiled tails. Cross sections of the organs were stamped on glass slides and histological examination of the organs was performed to find the portion where sperm with the abnormal tails appear. Many sperm with tails whose axoneme was exposed near the neck region were observed in the testis and they decreased in order from the caput, to the corpus, and the cauda epididymis. Sperm with detached tails and sperm with coiled tails gradually increased in the epididymis. These findings indicate that the tails of sperm with an exposed axoneme detached in the epididymis.     

Influence of a PGF2alpha-analogue, etiproston tromethamine, on the functional corpus luteum of dogs

To induce luteal regression-related abortion/delivery and treat pyometra in dogs, various PGF2alpha-analogues (PGAs) are administered, but a PGA most appropriate for clinical application in dogs, with a low incidence of side effects, is being investigated. In this study, we compared the effects of etiproston tromethamine (PGA-E), which has not been investigated in dogs, with those of cloprostenol (PGA-C), which is routinely used in dogs. A single dose of PGA-E at 100, 200, 400 or 800 microg or PGA-C at 12.5, 25, 50 or 100 microg was administered to beagles (n=5 per group) 25 days after ovulation, when the corpus luteum was in the functional phase. We compared the state of luteal regression by measuring plasma progesterone levels. As side effects, the incidences of salivation, vomiting, tachypnea, diarrhea and the drop in body temperature were investigated. In the 400-microg and 800-microg groups treated with PGA-E, the mean intervals from administration until luteal regression were 18.6 days and 31.2 days, respectively. In the dogs treated with 50 microg or more of PGA-C, luteal regression was noted 2 days after administration. The above side effects were observed for 3 hr after administration of PGA-E/PGA-C. In the dogs treated with 800 microg of PGA-E, the mean body temperature was 36.7 degrees C 4 hr after administration; hypothermia persisted. PGA-E may be less useful than PGA-C for promoting luteal regression in dogs in clinical application.     

Changes in plasma testosterone levels and semen quality after 3 injections of a GnRH analogue in 3 dogs with spermatogenic dysfunction

Three male Beagles with low plasma luteinizing hormone and testosterone levels and spermatogenic dysfunction (SD-dogs) were given 3 weekly subcutaneous injections of a gonadotropin-releasing hormone analogue (Buserelin; GnRH-AB). The plasma T level of all of the SD-dogs increased and peaked at 4-6 weeks after the first injection. The total number of sperm and the sperm motility of the three SD-dogs increased 5-7 weeks after the first injection. Therefore, the authors concluded that 3 weekly injections of GnRH-AB transiently improves semen quality in some cases of canine spermatogenic dysfunction.     

Effects of long-term oral administration of ketoprofen in clinically healthy beagle dogs

To investigate the adverse effects of long-term administration of ketoprofen in dogs, ketoprofen (1 mg/kg) was administered to five clinically healthy beagle dogs (ketoprofen group) and gelatin capsules (control group) were administered to four clinically healthy beagle dogs for 30 days. We monitored the dogs through periodic physical examination, blood analyses, endoscopic examinations, fecal occult blood tests, renal function tests, urinalysis, urinary enzyme indices and cuticle bleeding time analysis. The lesions in the stomach, especially in the pyloric antrum, and fecal occult blood progressively worsened in the ketoprofen group. However, the differences between the ketoprofen group and the control group were not statistically significant. One dog in the ketoprofen group temporarily exhibited a decrease in renal plasma flow and two dogs exhibited enzymuria. However, these changes did not persist and the other examinations showed no significant difference between premedication and postmedication in the ketoprofen group. Therefore, the adverse effects of long-term administration of ketoprofen observed in this study were not clinically important in healthy dogs. Nevertheless, further investigation of adverse renal effects from long-term administration of ketoprofen is necessary in the dogs with subclinical renal disease.