Prediction of clinical mastitis outcomes within and between environments using whole-genome markers.

The objective of this study was to evaluate genome-enabled predictions of daughter yield deviations for clinical mastitis in Norwegian Red cows within and between environments according to mastitis pathogen status. Genome-based predictions of daughter yield deviations for clinical mastitis for 1,126 bulls within and between 5 environments were performed using Bayesian ridge regression. The environments were defined as herd-5-yr classes with the following prevalence of bacteriological milk samples found positive for contagious mastitis pathogens: <50% (L50), ≥ 50% (H50), ≤ 25% (L75), >25% and <75% (M75), and ≥ 75% (H75). In addition, predictions based on all data across environment groups (the full data set, FD) were calculated to provide a benchmark for comparison. Predictive ability was evaluated using a 10-fold cross validation. A bootstrap procedure was used to obtain 95% confidence intervals for the cross-validation distribution of predictive ability for each data set. Predictive ability ranged from 0.04 for L75 to 0.19 for FD. Similar predictions within and between environments showed no evidence of genotype by environment interaction. The 95% confidence interval for all 5 environmental data sets included zero and ranged from 0.02 to 0.35 for FD. The bootstrap distribution showed large variation within each data set and small variation between data sets. Although we found no evidence of genotype by environment interaction, rank correlations of the single nucleotide polymorphism effects between different environments ranged from 0.15 (L75 - H75) to 0.92 (M75 - FD), indicating that single nucleotide polymorphisms may have a differential contribution to predictive ability in environments with distinct pathogen loads.

Genetic associations between somatic cell score and pathogen-specific subclinical mastitis in Norwegian Red cows.

The aim of this study was to estimate heritabilities of and genetic correlations between pathogen-specific subclinical mastitis (SCM) traits and lactation mean somatic cell score (LSCS) in Norwegian Red cattle. Based on data from 130 733 first-lactation cows four binary pathogen-specific SCM traits, Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis and coagulase-negative staphylococci SCM, were analysed together with unspecific SCM and LSCS using a multivariate sire model with threshold models for binary traits and a linear model for LSCS. Posterior means (SD) of heritabilities were 0.17 (0.01) for LSCS, 0.11 (0.01) for liability to unspecific SCM and ranged from 0.04 (Staph. aureus) to 0.14 (Strep. dysgalactiae) for liability to pathogen-specific SCM. Genetic correlations were positive and moderate to high, ranging from 0.37 to 0.98. All genetic correlations except the one between LSCS and unspecific SCM were lower than 1, indicating that SCM caused by different pathogens can be considered as partly different traits.

Genetic analysis of pathogen-specific clinical mastitis in Norwegian Red cows.

The objective of this study was to estimate heritabilities and genetic correlations for pathogen-specific clinical mastitis (CM) in Norwegian Red cows. In Norway, breeding values for mastitis are predicted based on records of veterinary treatments of clinical mastitis. Bacteriological milk sample results from the mastitis laboratories have been recorded routinely into the Norwegian Dairy Herd Recording System since 2000, but have so far not been used in genetic analyses. This additional source of data may provide valuable information on pathogen-specific CM. Records from 234,088 first-lactation Norwegian Red cows, daughters of 1,656 sires, were used for genetic analyses of unspecific, Staphylococcus aureus, Streptococcus dysgalactiae, and Escherichia coli CM. The 4 CM traits were defined as binary and scored as 1 if the cow had at least 1 case of the CM in question and 0 otherwise. A Bayesian approach using Gibbs sampling was applied, and a multivariate threshold liability model was used for the analyses. The posterior mean (SD ≤ 0.01) of the heritabilities were 0.06 for liability of unspecific CM, 0.04 for Staph. aureus CM, 0.02 for Strep. dysgalactiae CM, and 0.03 for E. coli CM. The posterior mean (SD) of the genetic correlations were all high, ranging from 0.75 (0.14) to 0.87 (0.07). The highest genetic correlation was found between unspecific CM and Strep. dysgalactiae CM, whereas the lowest was found for E. coli CM and Staph. aureus CM. Genetic correlations lower than 1 indicate that mastitis caused by different pathogens can be considered as partly different traits. In spite of high rank correlations (0.95-0.98), some re-ranking of sires was observed.

[Results after surgery of incisional hernias]. / Resultater efter operation for hernia incisionalis.

The purpose of this paper is to describe the subjective results after operation for ventral hernia. Patients operated for ventral hernia in the period from January 1, 1988 to December 31, 1992 were sent a questionnaire with a response rate of 87%. Forty-five percent had lasting discomfort, 30% were absent due to illness more than eight weeks after the operation and 22% were not able to go to work. These factors increase with the number of hernia operations. Regardless of the number of operations, about 70% of the patients wanted a new operation should the hernia recur. It is therefore important to give the patient an objective and detailed information to prevent from unrealistic expectations of the results of ventral hernia operation.

[Incisional hernia. A study of morbidity, mortality and bed utilization in a Danish county]. / Hernia incisionalis. En opgørelse af morbiditet, mortalitet og sengedagsforbrug i et dansk amt.

Four hundred and four patients operated for ventral hernia during a five year period were reviewed with special emphasis on morbidity, mortality and number of days in hospital. The patients were divided into 357 patients who had been operated for ventral hernia only once (A) and 47 patients who had been operated more than once for ventral hernia (B). There were no significant differences between the two groups regarding to ages or preoperative condition. The postoperative complications were 21% in group A and 12% in group B, although this was not statistically significant. Of those who suffered a complication after the operation, 76% had a competing illness prior to the operation. The overall mortality was 0.5%. The patients were hospitalized for a total of 4846 days. In view of the results of this material and of the high recurrence rate demonstrated in the literature, a restrictive attitude towards operations for ventral hernia is recommended.