Quarter- and cow-level risk factors for intramammary infection with coagulase-negative staphylococci species in Swiss dairy cows.

Bacteriological status, evaluation of udder symmetry, udder hygiene, and teat end scores of 92 dairy cows were assessed on 3 Swiss dairy farms in a longitudinal 1-yr study to determine risk factors for intramammary infection (IMI) with coagulase-negative staphylococci (CNS) species. Farm visits were performed monthly including sterile quarter milk sampling and udder evaluation of all lactating cows. Milk samples were evaluated for the presence of staphylococci using selective agar plates. Species identification was performed using MALDI-TOF mass spectrometry. Intramammary infection was defined as milk samples having ≥100 cfu per mL of milk according to culture results. Overall, 3,151 quarter samples were included in the statistical analysis. Staphylococcus chromogenes, Staphylococcus haemolyticus, Staphylococcus xylosus, and a Staphylococcus warneri-like species were the 4 most prevalent CNS species found. Hierarchical multivariable logistic regression models were built to evaluate risk factors for species-specific CNS IMI. Risk factors for Staph. chromogenes IMI were presence in herd B, the period from June 2014 to August 2014 and December 2014 to February 2015, and presence of udder edema. For Staph. haemolyticus, the relevant risk factor included coinfection with Staph. xylosus coinfection with other than the above-mentioned CNS species ("others") and the period from June 2014 to November 2014. Coinfection with Staph. haemolyticus and "others," the periods from June 2014 to August 2014 and December 2014 to February 2015, early phase of lactation (1-60 d in milk), and belonging to herd B were significantly associated with Staph. xylosus IMI. Mid and late lactation, coinfection with Staph. xylosus, and the period September 2014 to May 2015 were identified as significant risk factors for Staph. warneri-like IMI. For Staph. chromogenes, 60.6 and 26% of the variance was observed at the quarter and cow level, respectively, whereas for the other investigated species the highest variance was observed at the sample level. The predominant species within herds differed and was most pronounced for the Staph. warneri-like species.

Relationships between antral follicle count, blood serum concentration of anti-Müllerian hormone and fertility in mares.

INTRODUCTION: The anti-Müllerian hormone (AMH) plays an inhibitory role during folliculogenesis by regulating the number of follicles entering the growing pool. Antral follicle counts (AFC) are highly correlated with serum AMH concentrations and both appear to be related to the ovarian reserve in several species. Few data on AMH and AFC in mares exist, especially with regard to fertility. Therefore, the objective of the current study was to investigate the interrelationship between antral follicle count, serum AMH concentrations and fertility outcome in mares. One hundred and twenty-seven mares were enrolled in the study and grouped according to their reproductive status. Around time of estrus, serum AMH concentrations and AFC before and after ovulation were determined. Mares were artificially inseminated and pregnancy diagnosis was performed 14 to 18 days later. A high inter-individual variability in AFC and AMH concentration and a positive relationship between AMH and AFC for follicles ≤ 30 mm in diameter were observed, with a stronger correlation in mares older than 18 years. A high correlation between AFC measurements before and after ovulation was identified. The AFC after ovulation was higher than AFC before ovulation. AMH concentrations were neither related to the mares' reproductive status nor to age, number of cycles needed for pregnancy and pregnancy outcome. Excepted for a higher AFC in the middle-aged mares (9-18 years) compared to the younger mares (< 9 years), no associations between AFC and age, reproductive status as well as fertility of mares were found. This study confirms the relationship between AFC and AMH and a high degree of reproducibility of AFC measurements. However, based on our findings, neither AFC nor AMH are useful predictors of fertility in mares.

INTRODUCTION: Il existe peu de données sur l'AMH et l'AFC chez les juments, particulièrement en rapport avec la fertilité. L'objectif de cette étude était donc d'examiner la relation entre le compte de follicules antraux, le taux sérique d'AMH et la fécondité chez les juments. Cent vingt-sept juments ont été inclues dans l'étude et groupées selon leur état reproducteur. Les taux sériques d'AMH et l'AFC ont été déterminés pendant l'oestrus avant et après l'ovulation. Les juments ont été inséminées artificiellement et le diagnostic de gestation réalisé 14 à 18 jours plus tard. Une grande variabilité interindividuelle de l'AFC et l'AMH et une corrélation positive entre l'AMH et l'AFC pour les follicules de diamètre ≤ 30 mm ont été observées, cette dernière étant plus forte chez les juments âgées de plus de 18 ans. L'AFC après ovulation était supérieur à l'AFC avant ovulation, et une forte corrélation entre les deux mesures a été constatée. Aucun lien entre les taux sériques d'AMH, l'état reproducteur, l'âge, le nombre de cycles œstraux par gestation et le taux de gestation n'a été observé. Hormis un AFC supérieur chez les juments d'âge moyen (9-18 ans) comparé aux juments plus jeunes (.