Hematological and biochemical features of postpartum fever in the heavy draft mare.

Heavy draft mares potentially have a higher risk of suffering from postpartum fever (PF) than light breed mares. The purpose of this study was to compare hematological and biochemical features between clinically healthy mares (n=40) and PF-affected mares (n=16). Mares were classified as having PF when their rectal temperature rose to >38.5°C within 96 hr of foaling. The numbers of leukocytes, lymphocytes, and neutrophils and the serum magnesium level were significantly lower in PF-affected mares. The serum SAA and NEFA levels were significantly higher in PF-affected mares. Strong inflammation responses, fat mobilization associated with negative energy balance and possibly endotoxin participate in hematological and biochemical features of PF in heavy draft mares.

Pilot study of bovine interdigital cassetteless computed radiography.

Twenty-one limbs of bovine cadavers (42 digits) were exposed to interdigital cassetteless imaging plate using computed radiography. The radiographic findings included exostosis, a rough planta surface, osteolysis of the apex of the distal phalanx and widening of the laminar zone between the distal phalanx and the hoof wall. All these findings were confirmed by computed tomography. The hindlimbs (19 digits) showed more changes than the forelimbs (10 digits), particularly in the lateral distal phalanx. The cassetteless computed radiography technique is expected to be an easily applicable method for the distal phalanx rather than a conventional cassette-plate and/or the film-screen cassetteless methods.

Effect of chronic hemoplasma infection on cattle productivity.

The present study evaluated the effect of hemoplasmosis on cattle productivity. Prevalence of bovine hemoplasma was examined by polymerase chain reaction (PCR) using whole blood samples collected from 93 breeding cows and their 71 calves in Hokkaido, Japan. Monthly milk production records and other clinical data were compared between Mycoplasma wenyonii (Mw)-infected, "Candidatus Mycoplasma haemobos" (CMh)-infected, co-infected and PCR-negative groups. Blood chemical parameters were obtained from the 93 cows and 64 calves. PCR results showed that 89.2% (83/93) of cows and 14.1% (10/71) of calves were positive for bovine hemoplasma. Based on productivity data obtained from the 93 cows, Mw-infected, CMh-infected and co-infected cows had significantly lower monthly milk yield compared to PCR-negative cows. Furthermore, decline in milk yield was prolonged in CMh-infected and co-infected groups. No significant differences were found for other clinical findings among the four groups. Calf birth weight tended to be lower for Mw-infected, CMh-infected and co-infected groups compared to the PCR-negative group. There were no significant differences in all blood parameters of cows and calves among the four groups. In addition, no significant differences were found in any parameter between hemoplasma-infected and PCR-negative calves.

Effects of exogenous oxytocin on uterine blood flow in puerperal dairy cows: the impact of days after parturition and retained fetal membranes.

The objective of this study was to examine whether an oxytocin challenge test (OCT), evaluated by measuring the changes in uterine blood flow using transrectal colour Doppler ultrasonography, is a suitable non-invasive method to determine uterine contractility in puerperal dairy cows. The changes in uterine blood flow during uterine contractions induced by oxytocin were evaluated on days 2 and 5 postpartum (pp). Twelve clinically healthy Holstein cows were randomly assigned into two groups: (1) oxytocin group (n=7), 50 IU oxytocin injected IM and (2) control group (n=5), 5 mL saline injected IM. Blood flow volume (BFV) and pulsatility index (PI) in the uterine arteries were determined before and after injection for 120 min on days 2 and 5 pp. BFV declined and PI increased rapidly after oxytocin injection on day 2 (P<0.05), whereas oxytocin on day 5 pp did not cause changes in blood flow parameters. The result confirmed that uterine responsiveness to oxytocin decreases with time postpartum in healthy cows. The same OCT was applied in cows with retained fetal membranes (n=6) on day 2 pp, however uterine blood flow showed no change after oxytocin injection. The results showed that an OCT on day 2 pp may be a useful method for investigating the uterine contractile response to oxytocin (reflected as the decrease of uterine blood flow) and the potential pathophysiology of uterine involution in cows.

Relationship between the Placental Retention Time and the Reproductive Performance at the Foal Heat in Thoroughbred and a Comparison with Heavy Draft.

The aim of this study was to clarify the relationship between the placental retention time (PRT) and the reproductive performance following mating at the foal heat in Thoroughbreds. For this purpose, we interviewed 292 farmers over a period of 3 years with questionnaires evaluating foaling, expulsion of placenta and reproductive performance at the foal heat in 1,432 mares. The obtained data were later compared with a previous study of heavy draft mares. The average of the PRT of the 1,432 Thoroughbred mares was 58 ± 88 min (mean ± SD). The mean PRT of Thoroughbreds was significantly shorter than that of the148 min of heavy draft mares. The incidences of retained placenta (RP) occurring in the Thoroughbred mares were 5.2 and 4.0%, for over 3 and 4 hr after foaling, respectively. The incidence of RP over 4 hr was significantly lower than that of 25% in heavy draft mares. The pregnancy rate at foal heat of the mares in which PRT was less than 3 hr was 37%, and it significantly decreased to 11% for those with PRT of more than 3 hr. In the comparison of the reproductive performance between Thoroughbred and heavy draft mares, the pregnancy rate of Thoroughbreds dropped drastically to 10% when PRT exceeded 40, and in consequence, the pregnancy rate of Thoroughbreds was significantly lower than the 30% of heavy draft mares, which had a PRT of over 4 hr. In conclusion, the Thoroughbred mares had a low incidence of RP, however, a PRT exceeding 3 hr severely affected the reproductive performance at the foal heat.

Peripartum back fat thickness of multiparous Holstein-Friesian cows with displacement of the abomasum or ketosis.

To establish a method to predict postpartum diseases using prepartum back fat thickness (BFT), the peripartum BFTs of 54 healthy multiparous cows before calving, which were diagnosed with postpartum displacement of the abomasum (DA), clinical ketosis or subclinical ketosis were compared with those of healthy cows from 8 weeks before the expected calving date to 8 weeks after calving. The peripartum BFTs of the cows with DA or clinical ketosis were significantly higher than those of healthy cows. The peripartum BFTs of the cows with subclinical ketosis were not significantly higher than those of the healthy cows.

Relationship between indocyanine green clearance test and feed intake and impaired hepatic function in dairy cows.

The purposes of this study were 1) to examine changes in the indocyanine green (ICG) clearance by feeding and 4-day fasting in dry cows, and (2) to investigate the relationship between ICG clearance and blood chemistry profile in postpartum cows. In 3 dry cows, post-feeding ICG half-life (T(1/2)) was shorter than the pre-feeding value, and post-fasting T(1/2) was longer than pre-feeding and post-feeding values. In 16 lactating cows, T(1/2) value at 2 weeks postpartum showed positive correlations with AST, T-Bil and γ-GTP. These results suggested that ICG clearance correlated with T-Bil and liver enzymes can be sensitive and accurate diagnostic marker for impaired liver function in dairy cows. In addition, ICG clearance is greatly affected by feeding and fasting.

Effect of short-term fasting on hepatic steroid hormone metabolism in cows.

In the present study, the effect of 4-day fasting on steroid hormone metabolism in the liver and secretion of LH was examined in cows. Six non pregnant, dry Holstein cows were used. The estrous cycle was synchronized in all cows using CIDR-Ovsynch. Cows were allocated to a control group (n=3) and a fasting group (n=3). In the fasting group, cows were fasted for four days from day -4 to day -1 (day 0=day of 2nd GnRH injection) but otherwise were fed ad libitum. The experiment was repeated in a crossover design after an interval of about one month. The peripheral progesterone (P(4)) concentration in the fasting group was significantly higher than in the control group on day -1 and 0. The peripheral estradiol-17ß concentration in the fasting group was also significantly higher than in the control group on day -1 and 0. The portal vein P(4) concentration in the fasting group was significantly higher than in the control group. On day 0, there was no difference in LH secretion between groups. The mean percentages of lipid droplets in liver cells in the fasting group were significantly higher than in the control group on day 0. These results suggest that short-term fasting leads to reduced hepatic steroid hormone metabolism by accumulation of fat in the liver, which causes high peripheral steroid hormone concentrations.

Use of contrast-enhanced CT in the diagnosis of abscesses in cattle.

We report here the non-contrast and contrast-enhanced computed tomography performed in two calves with brain abscess and multiple pulmonary abscesses with pharyngeal abscess, respectively. Contrast-enhanced computed tomography was useful in the diagnosis of these diseases in both calves. The diseases were confirmed by histopathological examination.

Purulent necrotic dislocation of the hip joint associated with umbilical infection in a foal.

A 42-day-old heavy draft horse fell into sudden astasia. Significant swelling and heat sensation of the left femoral region were observed. Because of a friction sound in the left hip, we supposed that the hip joint was dislocated or the hip bone was fractured. Computed Tomography (CT) examination showed that the left hip joint was dislocated and the left femoral head was disjunct. We carried out a pathological autopsy, and made a diagnosis of the foal as fracture of the hip bone and femoral head with suppurative umbilical arteritis. Pathologic changes in the umbilical artery and hind leg were completely unilateral, suggesting that left umbilical arteritis spread to the blood circulation, causing arthritis and dislocation of the hip bone.

Risk factors of infestation by Psoroptes spp. mites in buffalo (Bubalus bubalis) at smallholder farms in the Nile Delta region, Egypt.

The aim of the present study was to explore the prevalence and potential risk factors associated with infestation by Psoroptes spp. mites in buffalo at smallholder farms in the Nile Delta region, Egypt. A total of 318 out of 1234 buffalo in 77 small scale herds were examined. The age of buffalo varied from three months to seven years. In all, 53 (16.66%) buffalo were recorded to be infested; 51 (16.35%) with Psoroptes spp. mites and two cases (0.31%) with Chorioptes spp. mites. Multivariate logistic regression was performed for significant risk factors at univariate analysis on both animal and herd level. The results of multivariate analysis showed that, on the animal level, the prevalence was affected by animal age (P < 0.01; OR: 0.71; CI 95%: 0.441-1.11), season (P < 0.01; OR: 1.20; CI 95%:0.541-1.15), indoor management (P < 0.001; OR: 6.625; CI 95%:2.489 -17.631) and rearing with other animals (P < 0.01; OR: 2.22; CI 95%:1.340 -7.132). However, on the herd level, the prevalence was affected by indoor rearing (P < 0.05; OR: 22.4; CI 95%:2.75-16.431), mixed rearing with other animal species (P < 0.05; OR: 4.5; CI 95%:1.66-7.941), and season (P < 0.01; OR: 2.3; CI 95%:0.575-2.426). Clinically, mild skin lesions with mild pruritus were significantly prevalent in buffalo with the infestation by Psoroptes spp. mites (P < 0.001), where 33/51 cases showed mild lesions. Also, psoroptic mites had significant association with inappitence (P < 0.001). The result of the present study indicates that Psoroptes spp. mites are the most prevalent in buffalo in the Nile Delta Region, Egypt. Moreover, recognition of risk factors associated with mange mites in buffalo may enable the practitioner to establish the most appropriate control measures.

Rhabdomyosarcoma with posterior paresis and megaesophagus in a Holstein heifer.

A 7-month-old Holstein heifer presented with posterior paresis and megaesophagus. At post mortem examination, a nodular tumor was found attached to the thoracic wall and the eighth to eleventh thoracic vertebrae, adjacent to the left posterior pulmonary lobe. The tumor was diagnosed as rhabdomyosarcoma by histology. This is a very rare case of spinal infiltration of rhabdomyosarcoma in cattle.

Effective oxytocin treatment on placental expulsion after foaling in heavy draft mares.

The aim of this study was to establish the effectiveness of administration of oxytocin (OT) on placental expulsion after foaling. Four foaling mares with the placentas retained for up 1 hr after foaling received OT (50 IU) administration at 1 hr intervals before expulsion of the placenta. The changes in the plasma concentrations of OT and the PGF2alpha metabolite (PGFM) were investigated, and the influence of OT administration was considered. The results were as follows. The placenta was expelled after one to three OT administrations in all four mares that received OT. In two mares, which expelled the placenta within 30 min after OT administration, the OT concentration increased and remained high. Expulsion of the placenta was delayed in two mares, and one of these mares, which received three doses of OT beginning 1 hr after foaling, showed only a small increase in the OT concentration after the first administration; the other mare did not receive OT until 3 hr after foaling. The OT concentration was increased before placental expulsion in all the mares, and the PGFM concentration also increased in the two mares with retained placentas. In conclusion, we suggest that intramuscular administration of 50 IU of OT at 1-hr intervals beginning 1 hr after foaling is effective for inducing placental expulsion.

Brain abscess in a Japanese black calf: utility of computed tomography (CT).

Computed tomography (CT) was used for diagnosis of brain abscess in a 6-month-old, Japanese black calf presented with neurological dysfunction, compulsive circling and vision disturbance. CT images showed asymmetric lateral ventricles, and presence of intra-cranial multiple low absorption lesions surrounded by capsule suggestive of abscess in the right cerebral hemisphere. Postmortem examination revealed marked swelling of right cerebral hemisphere and olfactory bulb. Multilocular large abscess containing creamy pus was found to occupy most area of periventricular and lateral ventricle. Fusobacterium necrophrum was isolated from the abscess contents as the causative agent. These results demonstrate that CT is useful tool for tentative diagnosis of bovine brain abscess.

Relationship between peripartal plasma oxytocin and prostaglandin F(2alpha) metabolite and placental expulsion time in heavy draft mares.

The aim of this study was to clarify the relationship between circulating oxytocin (OT) and PGF(2alpha) metabolite (PGFM) in mares at the third stage of labor and placental expulsion time in order to investigate a cause of retained placenta of which the incidence increase in a heavy draft mare. Blood was sampled every 5 min from foaling to expulsion of the placenta in 18 heavy draft mares to evaluate circulating OT and PGFM. The relationships between OT and PGFM concentration and recorded placental expulsion times were investigated. The results were as follows (1) The highest level of OT concentration was observed close to foaling in 15 mares. (2) The OT concentrations close to foaling were variable with a large difference from the lowest concentration, 22.1 pg/ml, to the highest concentration, 209.3 pg/ml. (3) The highest level of PGFM was observed close to foaling in 17 mares. (4) During the 60 min following foaling, the OT concentrations of the mares (n=11) that had a shorter placental expulsion time (i.e., <1 h), were significantly higher than those of the mares (n=7) that had a longer placental expulsion time (i.e., >1 h; P<0.05). Collectively, the OT concentration immediately after foaling is negatively related to the placental expulsion time. Deficiency of OT secretion at foaling have should be considered as one of the causes of retained placenta in heavy draft mares.

Effect of suckling on the reproductive performance and metabolic status of obese Japanese black cattle during the early postpartum period.

The aim of our study was to investigate the effects of suckling on reproductive performance and metabolic status of obese (mean body condition score of more than 4.0 on a scale of 1-5) maternal Japanese Black cows during early postpartum period. We used 7 postpartum Japanese Black cattle. Four cows were suckled ad libitum (suckled) until completion of their first artificial insemination (AI), while 3 cows were not suckled at all because they were separated from their calves immediately after parturition (non-suckled). Body weight and plasma concentrations of metabolites and hormones were measured from wk 1 to 9 postpartum. Ovarian activity was detected using plasma progesterone concentration, and all cows received their first AI after application of the Ovsynch protocol at approximately 4 months postpartum. Although body weights of non-suckled cows increased during experimental period (P<0.05), those of suckled cows remained unchanged. Plasma concentrations of glucose of non-suckled cows were higher at wk 2 postpartum (P<0.05) and their levels of non-esterified fatty acid tended to be lower at wk 1 and 2 postpartum compared with suckled cows (P<0.1); however, these differences between groups were not observed with progression of postpartum period. In addition, plasma insulin concentrations of non-suckled cows were higher than those of suckled cows during experimental period (P<0.05). During sampling period (wk 0 to 9 postpartum), onset of normal ovarian cycle was observed in all non-suckled and 2 of 4 suckled cows, and it was delayed in other 2 suckled cows compared with non-suckled cows; however, 3 suckled cows conceived at the first AI after application of the Ovsynch protocol; none of non-suckled cows conceived at this time. Overall, we suggest that suckling seems to reduce increase of body weight after parturition, although it does not improve obesity, and influences conception despite delay in resumption of normal ovarian cyclicity in obese Japanese Black cows.

Pancytopenia with bleeding tendency associated with bone marrow aplasia in a Holstein calf.

An 11-day-old Holstein calf presented with a high rectal temperature and tachypnea. Treatment with antibiotics and non-steroidal anti-inflammatory drugs did not improve the clinical signs. Bleeding tendency, with several hemorrhage spots on the body surface, appeared five days after admission. Severe pancytopenia was observed in the blood examination. The calf died on the 11th day after admission with severe bleeding from an injection site. Necropsy findings revealed that the pancytopenia had resulted from severe bone marrow aplasia. A congenital disorder was suspected to be the cause of pancytopenia associated with bone marrow aplasia.

Relationship between the first ovulation within three weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cows.

The aim of this study was to investigate the relationship between the first ovulation within 3 weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cattle in Hokkaido, Japan. In Experiment 1, 110 cows (44 primiparous and 66 multiparous) were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent ovarian cycles. Milk samples were collected twice weekly from 7 to 100 days postpartum. The first ovulation was identified by an increase in milk progesterone (P4) to more than 1 ng/ml within 3 weeks postpartum. The numbers of cows showing ovulation and anovulation within 3 weeks postpartum were 31 (70.5%) and 13 (29.5%) in the primiparous cows and 35 (53.0%) and 31 (47.0%) in the multiparous cows, respectively. The patterns of ovarian resumption after calving were classified into two types (normal ovarian cycles and abnormal ovarian cycles) on the basis of milk P4 concentrations. Initiation of normal ovarian function in cows ovulated within 3 weeks postpartum occurred earlier than in anovulated cows regardless of the number of calvings (primiparous, 27.8 days vs. 44.4 days; multiparous, 30.6 days vs. 55.7 days; P<0.01). Out of the multiparous cows that ovulated within 3 weeks postpartum, initiation of normal ovarian function followed by a normal luteal phase was earlier than when it was followed by an abnormal luteal phase (25.5 days vs. 40.4 days; P<0.05). Milk P4 concentrations after the first ovulation were lower than those after the second ovulation in both the primiparous and multiparous cows (P<0.05). In Experiment 2, 22 multiparous cows were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent fertility. Blood samples were collected once a week from 0 to 3 weeks postpartum. The interval from parturition to first service in ovulated cows was shorter than in anovulated cows (68.4 days vs. 94.8 days; P<0.05). The conception rate by 100 days after calving tended to be higher in ovulated cows than in anovulated cows (50.0% vs. 16.7%, P=0.09). In conclusion, our data strongly suggests that ovulation within 3 weeks postpartum is a crucial phenomenon for subsequent resumption of ovarian function and conception, and thus it can be used as an index of subsequent reproductive performance.