Blood chloride abnormalities in diarrheic neonatal calves with metabolic acidosis.

The present study investigated the prevalence of blood chloride (Cl) abnormalities in diarrheic neonatal calves with metabolic acidosis and attempted to identify the most relevant electrolyte abnormality to these abnormalities. A retrospective analysis was conducted on the medical records of 157 diarrheic neonatal calves aged 10.3 ± 4.2 days old with metabolic acidosis. Hypochloremia, normochloremia, and hyperchloremia were observed in 8.9% (14/157), 43.3% (68/157), and 47.8% (68/157), respectively, of diarrheic calves with metabolic acidosis. This distribution remained similar regardless of age (under 8 days or 8 days and older). Furthermore, a multiple logistic regression analysis showed that variations in values for blood sodium [Na (regression coefficients 0.877; 95% confidence interval (CI) 13.977-134.195; P<0.01)], pH (regression coefficients -10.719; 95% CI -19.076- -2.362; P<0.05), and bicarbonate [HCO3- (regression coefficients -0.555; 95% CI -0.820- -0.290; P<0.01)] were associated with blood Cl abnormalities. The present results revealed that blood Na concentrations were more strongly associated with blood Cl concentrations than blood pH and HCO3- values. In the present study, diarrheic calves with hyperchloremia were characterized by normonatremia and extremely severe metabolic acidosis.

Optimal clinical dose of medetomidine for sedation of young cows during dehorning surgery.

The present paper reports on the clinical efficacy and optimal clinical dose of medetomidine for sedation of young cows during dehorning surgery. Medical records of 24 female Holstein cows that underwent dehorning surgery were used in this study. In four groups, the sedation of animals was carried out by one of the four intravenous treatments: 0.1 mg kg-1 xylazine (Xyl group, n = 6), 5.0 µg kg-1 medetomidine (5.0 Med group, n = 6), 10.0 µg kg-1 medetomidine (10.0 Med group, n = 6) or 20.0 µg kg-1 medetomidine (20.0 Med group, n = 6). The clinical sedation score (CSS) and heart rate (HR) were recorded. The CSSs after intravenous administration of each α2-adrenergic receptor agonist increased rapidly and peaked at 12.5 (10.0-16.0) at t = 20 min in the Xyl group, 11.5 (10.0-15.0) at t = 10 min in the 5.0 Med group, 16.0 (14.0-16.0) at t = 20 min in the 10.0 Med group and 16.0 (14.0 - 16.0) at t = 20 min in the 20.0 Med group. A similar degree of bradycardia was observed after every sedative treatment. We conclude that the intravenous administration of 10.0-20.0 µg kg-1 medetomidine is appropriate for sedation of young cows without severe side effects.

Hydrogel particles as a particulate stabilizer for dispersion polymerization.

Hydrogel particles composed of poly(N-isopropylacrylamide) were used as a particulate steric stabilizer for the dispersion polymerization of styrene for the first time. The effects of the size and concentration of the hydrogel particles on the resultant polystyrene particles were investigated. As expected, the hydrogel particles indeed play the role of steric stabilizer for dispersion polymerization. Moreover, some of the resultant polystyrene particles were covered with hydrogel particles, which was confirmed by electron microscopy and X-ray photoelectron spectroscopy.