Profiles of serum amino acids to screen for catabolic and inflammation status in calves with Mycoplasma bronchopneumonia.

The aim of the present study was to investigate the relationships between serum amino acid profiles in normal and calves with Mycoplasma bronchopneumonia. Serum free amino acid concentrations in serum obtained from 34 calves with or without Mycoplasma bronchopneumonia were determined by high-performance liquid chromatography. The calves with Mycoplasma were characterized by significantly lower total amino acid and total essential amino acid concentrations and molar ratios of branched-chain amino acid (BCAA) to aromatic amino acid (BCAA/AAA) and BCAA to tyrosine (BTR), and by a significantly higher molar ratio of serine phosphorylation (SPR). The proposed diagnostic cutoffs for BCAA/AAA, BTR and SPR in serum based on ROC analysis for detection of catabolic states associated with Mycoplasma bronchopneumonia were set at <1.75, <2.86 and >0.85, respectively. Our results suggest that determining the profiles of amino acids, especially BTR and SPR, could provide useful diagnostic information in terms of predicting protein catabolism in Mycoplasma bronchopneumonia.

Changes in leukocyte populations of cows with milk fever or displaced abomasum after calving.

Most of the metabolic diseases of dairy cows occur within the first 2 wk after calving, and cows with a metabolic disease are prone to infectious diseases. Although metabolic diseases are generally recognized as a risk factor for infectious diseases owing to the associated decrease in immune function, the difference in immune status between cows with milk fever (MF) or displaced abomasum (DA) during the lactation period has not been clarified. Therefore, the peripheral blood leukocyte populations in 38 multiparous Holstein cows from 1 herd were analyzed after calving. The cows were divided into 3 groups according to health: 21 cows that remained clinically healthy throughout the experimental period (control group), 9 cows that had MF on the day of calving, and 8 cows with an onset of DA within 4 wk after calving. The T- and B-cell numbers were lowest at week 0, and they increased gradually after calving. There was no significant difference between the 3 groups in the number of each subset of leukocytes on the day of calving, but the number of CD8⁺ T-cells was significantly lower in the MF and DA groups than in the control group at week 1. The numbers of CD4⁺, CD8⁺, and WC1⁺ T-cells tended to be lower in the DA group than in control group from weeks 4 to 12, a tendency not observed in the MF group. These data suggest that when cows have DA around the time of calving, their lymphocyte numbers remain lower until 12 wk after calving.

La plupart des maladies métaboliques des vaches laitières se produisent à l'intérieur des 2 premières semaines après le vêlage, et les vaches avec une maladie métabolique sont sujettes aux maladies infectieuses. Bien que les maladies métaboliques soient généralement reconnues comme un facteur de risque pour les maladies infectieuses à cause de la diminution de la fonction immunitaire qui y est associée, la différence dans le statut immunitaire entre des vaches avec une fièvre du lait (MF) ou un déplacement de caillette (DA) durant la période de lactation n'a pas été clarifiée. Ainsi, les populations des leucocytes du sang périphérique de 38 vaches Holstein multipares provenant de un troupeau ont été analysées après le vêlage. Les vaches ont été divisées en trois groupes selon leur état de santé : 21 vaches qui sont demeurées cliniquement saines durant toute la durée de la période expérimentale (groupe témoin), 9 vaches qui ont eu une MF le jour du vêlage, et 8 vaches avec un début de DA dans les 4 sem après le vêlage. Le nombre de cellules T et B étaient à son plus bas la semaine 0, et il a augmenté graduellement après le vêlage. Il n'y avait pas de différence significative entre les trois groupes dans le nombre de chaque sous-groupe de leucocytes le jour du vêlage, mais le nombre de cellules T CD8+ était significativement plus faible dans les groupes MF et DA que dans le groupe témoin à la semaine 1. Le nombre de cellules T CD4+, CD8+ et WC1+ avaient tendance à être plus faible dans le groupe DA que dans le groupe témoin à partir de la semaine 4 jusqu'à la semaine 12, une tendance non observée dans le groupe MF. Ces données suggèrent que lorsque les vaches ont un DA durant la période du vêlage, leurs dénombrements lymphocytaires demeurent faibles jusqu'à 12 sem après la mise-bas.(Traduit par Docteur Serge Messier).

Molecular-based identification of yeasts isolated from bovine clinical mastitis in Japan.

This study analyzed molecular-based identification of yeasts that associated with bovine clinical mastitis in Japan. Over 3,200 quarter milk samples from Holstein dairy cows collected in 2011 on Hokkaido and Honshu islands were examined. Yeast isolates were characterized by polymerase chain reaction amplification and sequencing of the D1/D2 region of the 26S rDNA. Molecular characterization confirmed that Candida spp. and Pichia spp. were most frequently isolated species. Our molecular analysis of mastitic milk samples demonstrated the prevalence of Pichia kudriavzevii(22/58) and Candida tropicalis(14/58). In addition, we demonstrated that molecular analysis of the D1/D2 region of the 26S rDNA is a rapid and reliable method for identifying clinically significant yeasts in dairy hygiene, including potentially new or emerging pathogenic species.