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Helcococcus ovis ( H. ovis ) can cause disease in a broad range of animal hosts, including humans, and has been described as an emerging bacterial pathogen in bovine metritis, mastitis, and endocarditis. In this study, we developed an infection model that showed H. ovis can proliferate in the hemolymph and induce dose-dependent mortality in the invertebrate model organism Galleria mellonella ( G. mellonella ). We applied the model and identified H. ovis isolates with attenuated virulence originating from the uterus of a healthy post-partum dairy cow (KG38) and hypervirulent isolates (KG37, KG106) originating from the uterus of cows with metritis. Medium virulence isolates were also isolated (KG36, KG104) from the uterus of cows with metritis. A major advantage of this model is that a clear differentiation in induced mortality between H. ovis isolates was detected in just 48 h, resulting in an effective infection model able to identify virulence differences between H. ovis isolates with a short turnaround time. Histopathology showed G. mellonella employs hemocyte-mediated immune responses to H. ovis infection, which are analogous to the innate immune response in cows. In summary, G. mellonella can be used as an invertebrate infection model for the emerging multi-host pathogen Helcococcus ovis.

The objective of this study was to compare accuracies of different Bayesian regression models in predicting molecular breeding values for health traits in Holstein cattle. The dataset was composed of 2505 records reporting the occurrence of retained fetal membranes (RFM), metritis (MET), mastitis (MAST), displaced abomasum (DA), lameness (LS), clinical endometritis (CE), respiratory disease (RD), dystocia (DYST) and subclinical ketosis (SCK) in Holstein cows, collected between 2012 and 2014 in 16 dairies located across the US. Cows were genotyped with the Illumina BovineHD (HD, 777K). The quality controls for SNP genotypes were HWE P-value of at least 1 × 10 -10 ; MAF greater than 0.01 and call rate greater than 0.95. The FImpute program was used for imputation of missing SNP markers. The effect of each SNP was estimated using the Bayesian Ridge Regression (BRR), Bayes A, Bayes B and Bayes Cπ methods. The prediction quality was assessed by the area under the curve, the prediction mean square error and the correlation between genomic breeding value and the observed phenotype, using a leave-one-out cross-validation technique that avoids iterative cross-validation. The highest accuracies of predictions achieved were: RFM [Bayes B (0.34)], MET [BRR (0.36)], MAST [Bayes B (0.55), DA [Bayes Cπ (0.26)], LS [Bayes A (0.12)], CE [Bayes A (0.32)], RD [Bayes Cπ (0.23)], DYST [Bayes A (0.35)] and SCK [Bayes Cπ (0.38)] models. Except for DA, LS and RD, the predictive abilities were similar between the methods. A strong relationship between the predictive ability and the heritability of the trait was observed, where traits with higher heritability achieved higher accuracy and lower bias when compared with those with low heritability. Overall, it has been shown that a high-density SNP panel can be used successfully to predict genomic breeding values of health traits in Holstein cattle and that the model of choice will depend mostly on the genetic architecture of the trait., (© 2020 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.)

Klebsiella pneumoniae is a leading cause of severe infections in humans and dairy cows, and these infections are rapidly becoming untreatable due to the emergence of multidrug-resistant (MDR) strains. However, little is known about the relationship between bovine and human K. pneumoniae isolates at the genome population level. Here, we investigated the genomic structures, pangenomic profiles, virulence determinants, and resistomes of 308  K. pneumoniae isolates from humans and dairy cows, including 96 newly sequenced cow isolates. We identified 177 functional protein families that were significantly different across human and bovine isolates; genes expressing proteins related to metal ion (iron, zinc, and calcium) metabolism were significantly more prevalent among the bovine isolates. Siderophore systems were found to be prevalent in both the bovine and the human isolates. In addition, we found that the Klebsiella ferric uptake operon kfuABC was significantly more prevalent in clinical mastitis cases than in healthy cows. Furthermore, on two dairy farms, we identified a unique IncN-type plasmid, pC5, coharboring bla CTX-M-1 and mph (A) genes, which confer resistance to cephalosporins and macrolides, respectively. We provide here the complete annotated sequence of this plasmid. IMPORTANCE We demonstrate here the genetic diversity of K. pneumoniae isolates from dairy cows and the mixed phylogenetic lineages between bovine and human isolates. The ferric uptake operon kfuABC genes were more prevalent in strains from clinical mastitis cows. Furthermore, we report the emergence of an IncN-type plasmid carrying the bla CTX-M-1 and mph (A) genes among dairy farms in the United States. Our study evaluated the genomic diversity of the bovine and human isolates, and the findings uncovered different profiles of virulence determinants among bovine and human K. pneumoniae isolates at the genome population level., (Copyright © 2019 American Society for Microbiology.)

The main objective of the study reported here was to examine the association between pregnancy loss (PL) and previous exposure to clinical or subclinical mastitis before breeding or during gestation in primiparous Holstein cows. A secondary objective was to estimate the cost of clinical mastitis during gestation, including that of PL attributable to mastitis in study cows. A total of 687 primiparous Holstein cows from 1 dairy farm were included in a matched case-control study. Study cows were declared pregnant via ultrasound on d 33 after timed artificial insemination (TAI). Case cows (n = 78) were those diagnosed as nonpregnant by rectal palpation on d 47 or 75 after TAI. Control cows were those confirmed as pregnant by rectal palpation on d 47 and 75 after TAI. Case cows were matched with eligible controls according to year of calving and calving-to-conception interval ±3 d. Cows were assigned to 1 of 3 groups: (1) cows not affected with clinical or subclinical mastitis; (2) cows affected with subclinical mastitis (Dairy Herd Improvement Association somatic cell score >4.5); and (3) cows affected with clinical mastitis during 2 exposure periods, 1 to 42 d before breeding or during gestation (1 to PL diagnosis day for case cows, and 1 to 75 d for control cows). Conditional logistic regression was used to model the odds of PL as a function of previous exposure to mastitis in study cows. Mastitis before breeding was not associated with PL. The odds of PL were 2.21 times greater in cows affected with clinical mastitis during gestation (95% confidence interval = 1.01, 4.83), compared with cows without mastitis, after controlling for breeding type and lameness. The cost of clinical mastitis during gestation was $149, which includes the cost ($27) of PL attributable to mastitis. In conclusion, this study provides evidence that clinical mastitis during gestation can cause PL in primiparous dairy cows leading to economic losses., (Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The objective of this study was to conduct a systematic review to identify and assess evidence and knowledge gaps in published observational studies that have investigated the relationship between mastitis and pregnancy loss (PL) in dairy cows. PubMed and ScienceDirect were used to search pertinent peer-reviewed research reports of interest. Screening of research reports was conducted at 3 levels: titles, abstracts, and full-text articles. The search identified 651 records for initial screening. The final screening process identified 8 qualified articles for review after removing 10 duplicate records, 582 titles, 31 abstracts, and 20 full-text articles. Two studies produced strong epidemiologic evidence indicating that (1) exposure to clinical mastitis during early gestation (first 45 d of gestation) is associated with subsequent PL during the following 90 d; and (2) subclinical mastitis 1 to 30 d before artificial insemination (AI) is associated with subsequent PL at 35 to 41 d of gestation. An additional study showed that exposure to clinical mastitis during early lactation in combination with low body condition can increase the risk of PL in dairy cows; however, the interaction effect between clinical mastitis and low body condition on PL was considered weak. Four other studies produced inconclusive evidence indicating that mastitis is a predisposing factor for PL in dairy cows, as the exposure risk period for mastitis overlapped with the follow-up period for diagnosis of PL in dairy cows. Finally, one study failed to identify a relationship between mastitis and PL in dairy cows. Further research is needed to (1) support the hypothesis that mastitis in combination with low body condition score (or other exposure factors) can increase the risk of PL, (2) compare the effect of clinical versus subclinical mastitis on PL, (3) compare the effect of mastitis before breeding and during gestation on PL, and (4) compare the effect of mastitis on PL in dairy cows during different lactations., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The main objective was to evaluate the association between vulvovaginal laceration and uterine diseases in dairy cows. The secondary objectives were to evaluate the association between vulvovaginal laceration and cyclicity, and reproductive performance. The vulvovaginal region of 660 Holstein cows from a 5,000 lactating-cows herd was inspected at 4d in milk (DIM) for the presence of lacerations, and scored (VLS) as follows: 0=no laceration; 1=laceration <2cm at the dorsal commissure of the vulva or lateral walls of the vulva/vagina; 2=laceration ≥2cm at the dorsal commissure of the vulva or at the lateral walls of the vulva/vagina, or both. Vaginal discharge was scored at 4, 6, and 8 DIM for diagnosis of metritis, and then at 32 DIM for diagnosis of purulent vaginal discharge (PVD). Data were analyzed using LOGISTIC and PHREG procedures of SAS. Cows with VLS 2 had greater incidence of metritis than cows with VLS 0 (69.1 vs. 42.4%), and cows with VLS 1 tended to have greater incidence of metritis than cows with VLS 0 (52.0 vs. 42.4%). Cows with VLS 2 had greater incidence of PVD than cows with VLS 0 (56.5 vs. 43.1%). A lower proportion of cows with VLS 2 than VLS 0 were cyclic by 64 DIM (70.0 vs. 86.8%). A lower proportion of cows with VLS 2 than VLS 0 were pregnant at 60 d after first AI (28.7 vs. 33.6%). Proportion of pregnant cows at 60d after AI tended to be lower for VLS 1 than VLS 0 (28.4 vs. 33.6%). Hazard of pregnancy by 300 DIM was not affected by VLS. Hazard of pregnancy was decreased for cows with metritis, PVD, and anovular cows. In summary, vulvovaginal laceration was associated with uterine disease and cyclicity, which were negatively associated with reproductive performance. Vulvovaginal laceration was recognized as a risk factor for postpartum uterine disease., (Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

We present here the genome sequence ofEscherichia coliO8:H19 strain KCJ852, belonging to multilocus sequence type (MLST) 708, isolated from the uterus of a cow with a bovine postpartum uterine infection known as metritis. Genomic investigation of KCJ852 will help us understand its virulence potential., (Copyright © 2016 Ginn et al.)

The objective was to compare the reproductive efficacy of Ultrasynch, a synchronization program based on functionality of the corpus luteum as determined by ultrasonography, with an Ovsynch protocol. A randomized field trial was conducted on a commercial dairy in Cayuga County, New York, during scheduled weekly pregnancy examinations. Cows (n=745) determined nonpregnant 28 to 34 d after artificial insemination (AI) were randomly assigned to Ultrasynch or Ovsynch protocols. Cows assigned to the Ultrasynch management program (n=366) were treated based on corpus luteum (CL) diameter: cows with a CL > 23 mm received an injection of PGF(2alpha) and were bred via AI following detection of estrus (Ultra-PGF), whereas cows with a CL < or = 23 mm received injections and were bred on an Ovsynch protocol. Cows assigned to the Ovsynch management program (n=379) were placed on an Ovsynch protocol regardless of CL diameter. Pregnancy status was rechecked 28 to 34 d after AI; cows determined nonpregnant after initial enrollment were maintained in their assigned management group and received treatments based on CL diameter if in the Ultrasynch group and Ovsynch treatments if in the Ovsynch group. Hazard of pregnancy was similar between Ultrasynch and Ovsynch (hazard ratio=1.10, 95% confidence interval=0.88-1.36). Median days to conception were 98 and 87 for Ultrasynch and Ovsynch, respectively. The detection of estrus rate of cows in the Ultra-PGF group was 49%; better performance of an Ultrasynch management program may be achievable in a herd with a higher rate of estrus detection., (2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)