Review: extended lactation in dairy cattle.

This paper reviews the effects of extended lactation (EXT) as a strategy in dairy cattle on milk production and persistency, reproduction, milk quality, lifetime performance of the cow and finally the economic effects on herd and farm levels as well as the impact on emission of greenhouse gas at product level. Primiparous cows are able to produce equal or more milk per feeding day during EXT compared with a standard 305-d lactation, whereas results for multiparous cows are inconsistent. Cows managed for EXT can achieve a higher lifetime production while delivering milk with unchanged or improved quality properties. Delaying insemination enhances mounting behaviour and allows insemination after the cow's energy balance has become positive. However, in most cases EXT has no effect or a non-significant positive effect on reproduction. The EXT strategy sets off a cascade of effects at herd and farm level. Thus, the EXT strategy leads to fewer calvings and thereby expected fewer diseases, fewer replacement heifers and fewer dry days per cow per year. The optimal lifetime scenario for milk production was modelled to be an EXT of 16 months for first parity cows followed by an EXT of 10 months for later lactations. Modelling studies of herd dynamics indicate a positive effect of EXT on lifetime efficiency (milk per dry matter intake), mainly originating from benefits of EXT on daily milk yield in primiparous cows and the reduced number of replacement heifers. Consequently, EXT also leads to reduced total meat production at herd level. For the farmer, EXT can give the same economic return as a traditional lactation period. At farm level, EXT can contribute to a reduction in the environmental impact of dairy production, mainly as a consequence of the reduced production of beef. A wider dissemination of the EXT concept will be supported by methods to predict which cows may be most suitable for EXT, and clarification of how milking frequency and feeding strategy through the lactation can be organised to support milk yield and an appropriate body condition at the next calving.

A tailored implementation strategy to reduce the duration of intravenous antibiotic treatment in community-acquired pneumonia: a controlled before-and-after study.

We previously showed that 40 % of clinically stable patients hospitalised for community-acquired pneumonia (CAP) are not switched to oral therapy in a timely fashion because of physicians' barriers. We aimed to decrease this proportion by implementing a novel protocol. In a multi-centre controlled before-and-after study, we evaluated the effect of an implementation strategy tailored to previously identified barriers to an early switch. In three Dutch hospitals, a protocol dictating a timely switch strategy was implemented using educational sessions, pocket reminders and active involvement of nursing staff. Primary outcomes were the proportion of patients switched timely and the duration of intravenous antibiotic therapy. Length of hospital stay (LOS), patient outcome, education effects 6 months after implementation and implementation costs were secondary outcomes. Statistical analysis was performed using mixed-effects models. Prior to implementation, 146 patients were included and, after implementation, 213 patients were included. The case mix was comparable. The implementation did not change the proportion of patients switched on time (66 %). The median duration of intravenous antibiotic administration decreased from 4 days [interquartile range (IQR) 2-5] to 3 days (IQR 2-4), a decrease of 21 % [95 % confidence interval (CI) 11 %; 30 %) in the multi-variable analysis. LOS and patient outcome were comparable before and after implementation. Forty-three percent (56/129) of physicians attended the educational sessions. After 6 months, 24 % (10/42) of the interviewed attendees remembered the protocol's main message. Cumulative implementation costs were 5,798 (20/reduced intravenous treatment day). An implementation strategy tailored to previously identified barriers reduced the duration of intravenous antibiotic administration in hospitalised CAP patients by 1 day, at minimal cost.

A practical approach to estimate resting energy expenditure in frail elderly people.

OBJECTIVES: Some prediction equations of resting energy expenditure (REE) are available and can be used in clinical wards to determine energy requirements of patients. The aim of the present study was to assess the accuracy of those equations in sick elderly patients, using the Bland and Altman methods with our database of 187 REE measurements. DESIGN: The 3 equations tested were Harris and Benedict equation of 1919, WHO/FAO/UNU equation of 1985 and Fredrix et al. equation of 1990. In addition, three models developed from the present data were tested. RESULTS: The present study shows that the Fredrix et al equation gave an accurate prediction of REE without significant bias along the whole range of REE. It also shows that under-weight sick elderly patients (BMI

Bayesian inference of population expansions in domestic bovines.

The past population dynamics of four domestic and one wild species of bovine were estimated using Bayesian skyline plots, a coalescent Markov chain Monte Carlo method that does not require an assumed parametric model of demographic history. Four domestic species share a recent rapid population expansion not visible in the wild African buffalo (Syncerus caffer). The estimated timings of the expansions are consistent with the archaeological records of domestication.

Genetic variability of seven dog breeds based on microsatellite markers.

The present study, compared the genetic variability of seven dog breeds and a test sample from Switzerland by means of 26 microsatellite markers. Five loci were excluded from further analyses because one was monomorphic, one not in Hardy-Weinberg equilibrium in all breeds and three in linkage disequilibrium with linked loci. The proportion of shared alleles at the individual level of the remaining 21 microsatellite markers combined with the neighbour-joining method allowed for the clustering of the large majority of the individuals in accordance to their breed. The results were confirmed by analyses using a Bayesian approach for clustering and a Monte Carlo re-sampling method for individual assignment or exclusion to a given population.

Calf health in cow-calf herds in Switzerland.

In 1993, an observational study was initiated to provide general information on animal health in extensive beef farms, to estimate disease frequency and the economic impact of calf diseases and to identify risk factors related to health and weight gain. The longitudinal study was conducted from fall 1993 until winter 94/95 and included 100 farms in western Switzerland. The basic concept was to follow one generation of calves on these farms and record all events concerning animal health from birth to weaning. The study population included 1270 calves (most were Angus crossbreds). Farm-management data were collected with a questionnaire conducted on the farm. Birth and weaning weights were obtained from the beef cattle breeding association. Clinical diagnoses and treatment costs were provided by the farm veterinarians. Two thirds of the dead calves were submitted to a complete postmortem examination. Fifty-three percent of the farms in the study were primary type income farms while 47% were secondary type income farms. Thirty-eight percent of the farms were situated in the lower areas of Switzerland, 14% in the prealpine foothills, the remaining 48% were located in mountain areas. Preweaning calf mortality was 5%. The main causes of calf deaths were respiratory diseases and digestive disorders. Twenty-two percent of the calves were treated at least once by a veterinarian; 36% of the treatments administered by the veterinarian were applied because of diarrhea, 27% because of respiratory diseases. Disease incidence was highest during the months of November, December and January. The association of disease and potential farm-level risk factors was analysed using chi 2-statistics and multivariable regression methods including generalized estimating equations to adjusted for herd effects. Specific risk factors for disease were not identified. Treatment for disease was not associated with 250-day standardized weight gain.

Indications for antibiotic use in ICU patients: a one-year prospective surveillance.

The high prevalence of nosocomial infections in critically ill ICU patients is associated with high antibiotic consumption. Besides its economic impact, there is the constant threat of selection and induction of antibiotic resistance. Surveillance studies recording the incidence of infections, antibiotic use, and antimicrobial susceptibilities of pathogens supply vital information regarding infection control and prevention of antibiotic resistance. In order to analyse antibiotic consumption we recorded antibiotic use in a general ICU during one year by categorizing the indications for antibiotic use into three groups; (i) prophylaxis; (ii) therapy for a bacteriologically proven infection (BPI); (iii) therapy for a non-bacteriologically proven infection (non-BPI). Bronchoscopic techniques were used to diagnose pneumonia. In practice, BPI must be treated, but a proportion of antibiotics prescribed for non-BPI may be unnecessary. The subdivision in BPI and non-BPI may help to identify these cases. In all, 515 patients were admitted to ICU and 36% of these had at least one infection. Of all infections, 53% were ICU-acquired and 99% of these occurred in intubated patients. Antibiotics were prescribed in 61% of admissions. Of all antibiotics prescribed for therapy, 49% were for respiratory tract infections, 19% for abdominal infections and 13% for sepsis eci. Categorized by indication, 59% of all antibiotic prescriptions were for BPI, 28% for non-BPI and 13% for prophylaxis. A theoretical reduction of 25% in the number of non-BPI prescriptions would result only in a 7% decrease of total antibiotic use. We conclude that almost all antibiotics prescribed were for intubated patients and for BPI. Respiratory infections were the single most common infection and accounted for 49% of all antibiotics used. Therefore, in our setting, prevention of respiratory tract infections is probably the most effective mode to reduce antibiotic use.

Assessment of gastric acidity in intensive care patients: intermittent pH registration cannot replace continuous pH monitoring.

OBJECTIVE: To test the accuracy of colour-scaled indicator papers to measure pH values and to study the correlation between this method of measuring gastric juice pH once daily and 24-h continuous intragastric pH monitoring in intensive care patients. DESIGN: The accuracy of indicator papers was tested in the laboratory using colourless solutions and aspirated gastric juice and was then verified with a laboratory pH meter. Continuous intragastric pH monitoring was performed in mechanically ventilated ICU patients. Percentages of time with a pH value <3.0 and median pH values by 24-h continuous intragastric pH monitoring were compared to pH values measured once daily with indicator paper. SETTING: A mixed ICU. PATIENTS: A total of 150 measurements were taken by continuous pH monitoring in 91 mechanically ventilated ICU patients. MEASUREMENTS AND RESULTS: The correlation between the pH measured with the indicator paper and subsequently verified with a laboratory pH meter in colourless solutions was 0.96 [regression coefficient (RC) 0.98, 95% confidence interval (CI) 0.91-1.05]. Measured in gastric juice it was 0.95 (RC 0.95, 95% CI 0.88-1.01). The correlation between median pH values, determined with 24-h continuous intragastric pH monitoring, and values measured with indicator papers was 0.39 (RC 0.43, 95% CI 0.26-0.59). The mean difference in pH, as determined by the analysis of Bland and Altman], was 0.9 with a SD of 4.7. The correlation between the percentage of time with pH < 3.0, as obtained with continuous registration, and median gastric pH values (also obtained with continuous registration) was -0.94 (RC-0.06, 95% CI-0.06- -0.05); the correlation between the time and gastric pH values (measured with indicator paper) was-0.40 (RC-0.02, 95% CI-0.03- -0.02). CONCLUSION: The colour-scaled indicator paper is an accurate method of measuring pH values, but there is a poor correlation between gastric pH values measured once daily and a total measurement derived from 24-h continuous intragastric pH monitoring. Changes in intragastric pH values cannot be accurately studied when measuring acidity once daily. The influence of various treatment regimens on intragastric acidity in relation to the development of gastric colonization and nosocomial pneumonia should be investigated either with continuous intragastric monitoring or with frequent measurements in aspirated gastric juice.