Postmortem magnetic resonance imaging findings of tricuspid atresia with ventricular and atrial septal defects and subvalvular pulmonic stenosis in a Japanese native Noma horse.

The necropsy of a 2-day-old Noma horse that died of weakness showed an enlarged cardiac base and a narrow cardiac apex, suggesting cardiac malformation. The excised heart underwent imaging to investigate its luminal structure. On three-dimensional magnetic resonance imaging, the right atrium and right ventricle were discontinuous. The right atrium communicated with the left atrium and the left ventricle communicated with the right ventricle. The lumen narrowed near the pulmonary artery valve. Since the same findings were observed on gross examination, the foal was diagnosed with tricuspid atresia with ventricular and atrial septal defects, along with subvalvular pulmonic stenosis.

Relationships between the age and blood test results or body sizes in Noma horses.

The objective of this study is to analyze the relationships between the age and blood test results or body sizes in Noma horses by using the results of periodical health examination. Out of 45 hematological or physical items examined, statistically significant, but loose correlations were observed in 14 items. Red blood cell count, activities of aspartate aminotransferase, alkaline phosphatase, and creatinine kinase, concentrations of calcium and inorganic phosphorus decreased with aging. Conversely, mean corpuscular volume, mean corpuscular hemoglobin, lipase activity, γ-globulin and chloride concentrations, body height, chest circumference and cannon bone circumference increased with aging. The changes in a few items seemed unique to Noma horse. However, most age-related changes found in this study might be considered as a common trend in horse breeds rather than distinctive characteristic in Noma horse.

An anatomical study of the skull, the dorsal and ventral nasal conchal bullae and paranasal sinuses in normal Noma horses: Computed tomographic anatomical and morphometric findings.

Noma horses have the smallest body size among native Japanese horses and are classified as pony breeds by their size. Additionally, the Japanese horse breeds are classified into a single lineage, which includes Mongolian horses. Great intraspecific differences reportedly exist in the head shapes of domesticated horses, which have been investigated in various horse breeds. The present study aimed to evaluate the size of the nasal conchal bullae, and the paranasal sinuses of Noma horses in relation to the skull dimensions using computed tomography. Reconstructed images of the heads of five adult Noma horses were used. Skull and paranasal sinus parameters were measured and analysed in relation to each other and were compared with the data in the literature on the skulls of various horse breeds. In comparison with pony breed, Shetland ponies and donkeys had a shorter nasal length than cranial length, while Noma horses had a longer nasal length than cranial length, similar to the larger breeds. In the nasal conchal bullae, Shetland ponies showed a negative correlation between the head and bullae size, while Noma horses, similar to larger breeds, had a positive correlation. In conclusion, our findings suggest that Noma horses, despite having a body size that belongs to the pony breed, had a distinguishing ratio of the skull and paranasal sinuses similar to that of the larger breeds. Our results provide information on the physiological morphology of the head and comparative anatomy based on genetic diversity in horses.

Effect of seasons and sex on the physical, hematological, and blood biochemical parameters of Noma horses.

This study aimed to evaluate the influence of seasons and sex on body size and hematological and biochemistry parameters of Noma horses, a native Japanese breed. Body size was larger in winter than in summer. Laboratory testing variables, including erythrocytic parameters and urea nitrogen, total cholesterol, and creatinine kinase levels, were higher in winter, while the eosinophil count was higher in summer. These seasonal differences may be related to increased energy consumption of horses due to heat stress. The higher eosinophil counts may have been related to the dermatitis observed in summer. Stallions tended to have smaller bodies compared with mares. Future studies are necessary to investigate the effect of stress in seasonal and sex-based groups.

Forestomach developmental failure in an 11-month-old Japanese Black steer with severely retarded growth and chronic ruminal tympany.

This study reports findings from the pathological examination of the forestomach of an 11-month-old Japanese Black steer with severely retarded growth (41% of expected weight) and chronic ruminal tympany. The ruminal papillae were weakly formed (0.3-0.5 cm long) and unevenly distributed. The cellulae and cristae reticuli were underdeveloped; the cristae were 0.4-0.7 cm in height and milky white. The keratinized layer in the stratified squamous epithelium was thickened. Ruminal pH was 5.25, and ruminal volatile fatty acid concentration was 11.7 mM. The steer's severely retarded growth was considered to be caused by malnutrition due to developmental and functional failure of the forestomach.

Colostral and foal serum immunoglobulin G levels and associations with perinatal abnormalities in heavy draft horses in Japan.

The purpose of this study was to elucidate the colostral and foal serum immunoglobulin G (IgG) concentration values in heavy draft horses in Japan and to examine the effects of peripartum mare condition on colostral immunity. Colostrum was obtained 1 hr after foaling (pre-suckling; n=178). Blood was collected from the jugular vein of the foals (n=147) at 24 to 48 hr after birth. The foaling statuses of 73 mares were recorded. The average colostral IgG concentration was 10,540 ± 3,190 mg/dl (median=10,928; range 1,434-17,514 mg/dl). The average serum IgG concentration obtained from neonatal foals 24 to 48 hr after birth was 1,750 ± 919 mg/dl (median=1,890; range 0-3,510 mg/dl). Although colostral IgG did not differ between the normal foaling mare (n=59) and dystocial mare (n=14), foal serum IgG was lower in foals born in dystocia than in foals in normal foaling (P<0.05). This study demonstrates reference values for colostral and foal serum IgG specific to heavy draft horses in Japan and suggests that dystocia may interfere with the acquisition of colostral immunity in neonatal foals.

Reference values of hematological and blood biochemical parameters for the Noma horse.

The Noma horse is a Japanese breed from the Noma region of Imabari City, Ehime Prefecture. To obtain reference hematological and biochemical values, we performed examinations in 39 clinically healthy, mature Noma horses managed at the Imabari public ranch. Hematological and biochemical results of Noma horses were close to the normal ranges of horses in the U.S.A. The erythrocyte parameters and hepatobiliary enzyme levels in Noma and Kiso horses were lower than those in Japanese racehorses. Noma horses showed higher erythrocyte parameters and triglyceride concentrations and a lower creatinine concentration compared with those in Kiso horses. These data represent the first report of reference values for Noma horses and may be useful to improve their management.

Humeral fracture in a Japanese Black calf repaired by closed approach and two methods of external skeletal fixation.

A healthy 71-day-old female Japanese Black calf was evaluated for fracture of the left humerus. The left humeral fracture was treated by closed repair and unilateral external skeletal fixation (ESF) with an epoxy putty fixator. The calf was active, and eight days after surgery slipped and fell, resulting in breakage of the ESF. The calf underwent repair by transfixation pinning and casting (TPC), which is an alternative to the ESF method. The TPC was removed 37 days after the first surgery, and the calf could bear weight on the left forelimb while walking. This case suggests that recovery after closed repair with TPC for a humeral fracture in an active calf can be successfully managed on the farm.

Experimental assessment of bone mineral density using quantitative computed tomography in holstein dairy cows.

The aim of this study was to assess the measurement of bone mineral density (BMD) by quantitative computed tomography (QCT), comparing the relationships of BMD between QCT and dual-energy X-ray absorptiometry (DXA) and between QCT and radiographic absorptiometry (RA) in the metacarpal bone of Holstein dairy cows (n=27). A significant positive correlation was found between QCT and DXA measurements (r=0.70, P<0.01), and a significant correlation was found between QCT and RA measurements (r=0.50, P<0.01). We conclude that QCT provides quantitative evaluation of BMD in dairy cows, because BMD measured by QCT showed positive correlations with BMD measured by the two conventional methods: DXA and RA.

Relationship between diarrhea and peripheral leukocyte population in neonatal Japanese black calves.

Neonatal Japanese Black (JB) calves show a high incidence of diarrhea. The objective of this study was to analyze the immune cell populations of neonatal JB calves in detail and examine its correlation with the incidence of diarrhea immediately after birth. Understanding the immune cell populations is helpful in clinics in order to determine the condition of the immune system for prevention of diseases. Blood samples were obtained from JB calves on the day of birth. The peripheral leukocyte populations were analyzed separately for calves that had diarrhea within 2 weeks after birth (diarrhea group; n = 26) and for calves without diarrhea (control group; n = 74). The numbers of the peripheral blood CD3(+)TcR1-N12(+) and CD8(+) T cells were significantly lower in the diarrhea group compared with the control group. These findings suggest that the congenital lower peripheral γδ and CD8(+) T cells results in a high risk of diarrhea in neonatal JB calves.

Whole genome characterization of new bovine rotavirus G21P[29] and G24P[33] strains provides evidence for interspecies transmission.

We have reported a novel bovine rotavirus, the AzuK-1 (G21P[29]) strain, isolated from an asymptomatic calf. We isolated another bovine rotavirus, the Dai-10 strain, bearing new G24P[33] genotypes, assigned by the Rotavirus Classification Working Group (RCWG), from an asymptomatic cow in Hyogo Prefecture, Japan in 2007. To gain an insight into the origins and evolution of these strains, we determined the complete ORF sequences of all 11 genes of the two strains. The NSP3 genes of both strains were confirmed to belong to a new NSP3 genotype, T9, by the RCWG. Genotype determination of AzuK-1 and Dai-10 strains revealed that eight gene segments of both strains possessed genotypes typically observed in bovine rotaviruses, with the exception of VP4, VP7 and NSP3 gene segments. Unexpectedly, phylogenetic analyses showed that VP6 and NSP2 gene segments of the AzuK-1 and Dai-10 strains were clustered with those of simian or canine/feline rotaviruses, rather than with those of bovine rotaviruses. These findings indicate the possibility that both strains originated by interspecies transmission and multiple reassortment events involving bovine, simian and canine/feline rotaviruses, resulting in the introduction of some genes into the genetic background of bovine rotaviruses.

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.

Serum free amino acid concentration in hepatic lipidosis of dairy cows in the periparturient period.

Blood samples were taken from eight multiparous cows at a dairy farm on eight occasions between the prepartum period and peak lactation to study the serum concentrations of amino acids and biochemical constituents. The cows were classified as having either severe hepatic lipidosis (HL) or non-hepatic lipidosis (non-HL) according to their clinical condition after calving and changes in serum biochemical parameters. The serum concentrations of beta-hydroxybutyric acid were higher in the HL group than in the non-HL group (ANOVA: p<0.01). The serum concentrations of methionine (Met), phenylalanine, and arginine were significantly different between the two groups (ANOVA: p<0.05). In particular, the Met levels were significantly low for 14 days after calving in the HL group (p<0.05), although Met levels in the HL group tended to be lower than the values in the non-HL group until 30 days after calving, starting 14 days before calving. The results suggest that an insufficiency of Met during the periparturient period is related to the development of hepatic lipidosis.

Plasma vitamin C concentration is not related to the incidence of ketosis in dairy cows during the early lactation period.

Many animals including cattle can synthesize vitamin C from glucose. The objective of this study was to investigate plasma vitamin C concentration in ketotic cows during the early lactation period because glucose supply for vitamin C synthesis might be limited in these cows. We measured plasma beta-hydroxybutyrate (BHBA) concentration in 118 cows within 2 months after parturition. Subclinical/clinical ketosis was quantitatively determined using a plasma BHBA threshold of 1,200 microM. Plasma glucose concentration was lower in the ketotic cows than in the control cows but plasma vitamin C concentration did not differ between the control and the ketotic cows. Then we measured plasma vitamin C, BHBA and glucose levels in 7 cows during the periparturient period. Plasma BHBA increased and plasma glucose decreased after parturition but plasma vitamin C did not change. These results indicate that plasma vitamin C is not related to the incidence of ketosis in the early lactation period. We suggest that ketotic cows have the ability to produce vitamin C to meet its requirement in the early lactation period although glucose supply is not sufficient for milk production. Vitamin C synthesis is possibly given a high metabolic-priority for glucose in lactating cows.

The relationship between changes in serum glycine and alanine concentrations in non-essential amino acid and milk production in the transition period in dairy cows.

The serum concentration of non-essential amino acid (NEAA) was measured in ten Holstein dairy cows grouped as low production (n=5) and high production (n=5) from one month pre-partum through four months post-partum and the relationship between production and amino acid concentrations was studied. The glycine (Gly)/NEAA ratio and the glycine/alanine ratio of the high production group were significantly higher than the low production group (p<0.01). The observed decrease of the alanine (Ala)/NEAA ratio was more remarkable in the high production group than in the low production group. Measurement of Gly/Ala ratio in serum may be useful for evaluating the nutritional status of peri-parturient dairy cow.

Effects of follicle size and electrolytes and glucose in maturation medium on nuclear maturation and developmental competence of bovine oocytes.

The concentrations of electrolytes (Na, K, Cl, Mg and Ca) and glucose in small follicle (SF) follicular fluid (SFF) and large follicle (LF) follicular fluid (LFF) from slaughterhouse-derived ovaries were studied. Oocytes were matured in medium based on synthetic oviductal fluid. The effects of various concentrations of electrolytes (Na, K, Ca and Mg) and glucose in the maturation medium on the progression of nuclear maturation and subsequent development were also studied. K in SFF was significantly greater than that in LFF. The Mg concentration in follicular fluid (FF) is 2.0-2.3 mM, which is greater than the concentration present in medium generally used for culture. The glucose concentration in FF is about 3.5-3.9 mM and rapidly decreases during the preservation of ovaries. LF oocytes resumed nuclear maturation and progressed to the M2 stage significantly faster than those collected from SF oocytes. In addition, more LF oocytes developed to blastocysts than did SF oocytes. Changing the Na/K ratio in the maturation medium from 16 to 24 did not affect either the progression of nuclear maturation or the rate of development. A low concentration of Mg (0.5 mM) combined with a low Ca concentration (0.5 mM) inhibited the rate of development, but did not affect the progression of nuclear maturation. On the other hand, increasing the Mg concentration to 2.0 mM from 0.5 mM hastened the progression of nuclear maturation and improved the rate of blastulation, irrespective of the Ca concentration. The progression of nuclear maturation was faster and the rate of development was greater with 5.56 mM glucose than with 1.5 mM glucose. The difference in time needed to progress to M2 among the experiment was about 2-3 h. Therefore, prolonging the maturation periods from 21 to 24 h did not change the rate of development. Our results show that the concentrations of Mg and glucose in the maturation medium and the follicle size enveloping the oocyte affect the progression of nuclear maturation and subsequent development. The time requirement for oocytes to reach M2 is strongly related to the developmental competence of the oocytes.