Fleckscore system of exterior evaluation as a more accurate indirect predictor of longevity in Slovak Simmental dairy cows

The goal of the work was to discover the influence of conformation traits evaluated by the Fleckscore system on the length of productive life of Slovak Simmental dairy cows. Evaluation of body conformation traits according to the Fleckscore system was performed on 3 452 cows. The relationship of individual traits to longevity was analysed using the Weibull proportional hazard model. The results confirmed that smaller and longer cows, which were well muscular and with a deeper body, had a lower risk of early culling than cows in the reference group. Hock angularity, pastern and hoof height scored with low or high marks were associated with an early culling of cows. In terms of the length of productive life, a slightly more elastic pattern is required. Cows with a deeper udder and a stronger and tighter fore udder attachment, which were also average in notching and height central ligament and centrally placed teats, reached a longer productive life.

Determinants of the Age at First Marriage among the University Teachers in Algeria: A mix Methodology Approach

This study examines the determinants of age at first marriage among the university teachers in Algeria. A Weibull proportional hazard and multivariable logistic regressions models were used on data set from a survey covering a sample of 682 teachers. The findings revealed that: The median ages at first marriage are: 36 and 39.4 years for men and women, respectively, with a gap of 3.1 and 8 years from the general population. For: birth order, teacher specialty, study place and working before joining the academic staff all together explain a very small percent of the variation of the age at marriage; in contrast, Housing, salaries’ level, and a suitable partner were the hidden factors determining the age at marriage. As policy implications, policy-makers have to focus on these factors in order to help teachers to satisfy this biological and sociological need. JEL Classification: C4; J12

Cardiovascular mortality and cardiovascular event rates in patients with inflammatory rheumatic diseases in the CARdiovascular in rheuMAtology (CARMA) prospective study—results at 5 years of follow-up

Objectives To determine cardiovascular (CV) mortality and incidence of the first CV event (CVE) in patients with chronic inflammatory rheumatic diseases (CIRD) after 5 years of follow-up. Methods This is an analysis of the CARdiovascular in rheMAatology (CARMA) study after 5 years of follow-up. It includes patients with RA (n = 775), AS (n = 738) and PsA (n = 721), and individuals without CIRD (n = 677) attending outpatient rheumatology clinics from 67 public hospitals in Spain. Descriptive analyses were performed for the CV mortality at 5 years. The Systematic COronary Risk Evaluation (SCORE) function at 5 years was calculated to determine the expected risk of CV mortality. Poisson models were used to estimate the incidence rates of the first CVE. Hazard ratios of the risk factors involved in the development of the first CVE were evaluated using the Weibull proportional hazard model. Results Overall, 2382 subjects completed the follow-up visit at 5 years. Fifteen patients died due to CVE. CV deaths observed in the CIRD cohort were lower than that predicted by SCORE risk charts. The highest incidence rate of CVE [7.39 cases per 1000 person-years (95% CI 4.63, 11.18)] was found in PsA patients. However, after adjusting for age, sex and CV risk factors, AS was the inflammatory disease more commonly associated with CVE at 5 years [hazard ratio 4.60 (P =0.02)], compared with those without CIRD. Conclusions Cardiovascular mortality in patients with CIRD at 5 years of follow-up is lower than estimated. Patients with AS have a higher risk of developing a first CVE after 5 years of follow-up.

Dairy Cow Culling - Reasons and Risk Factors

Background Culling is a major cost for dairy farms but also an essential part in managing herd productivity. This study aimed to identify the culling rates of Estonian dairy cows, identify the farmers’ stated reasons and risk factors for culling. This observational study used registry data of all cows from herds with ≥20 cow-years in 2013-2015. Cow lactation-level analyses included data of 86,373 primiparous cows from 409 herds and 177,561 lactations of 109,295 multiparous cows from 410 herds. Weibull proportional hazard regression models were used to identify risk factors for culling due to slaughter or death. Results The overall culling rate of Estonian dairy cows was 26.24 (95% CI 26.02; 26.46) per 100 cow-years. The most common reasons farmers stated for culling were feet/claw disorders (26.4%), udder disorders (22.6%), metabolic and digestive disorders (18.1%) and fertility problems (12.5%). Animal-level risk factors for culling were Holstein breed, older parity, lower milk yield breeding value, older age at first calving, longer previous calving interval, having assisted calving, stillbirth and birth of twins/triplets. Lower milk yield, somatic cell count over 200,000 cells/ml and fat/protein ratio over 1.5 at first test-milking after calving were associated with greater culling hazard during the lactation. Cows from larger herds, herds with decreasing size and higher milk yields had a higher culling probability. Conclusions This study emphasises the need for improved management of hoof health and prevention of mastitis and metabolic diseases. It is essential to ensure easy calving and good health of cows around calving in order to lower the culling hazard.

Dairy Cow Culling - Reasons And Risk Factors

Background Culling is a major cost for dairy farms but also an essential part in managing herd productivity. The study aimed to identify the culling rates of Estonian dairy cows, identify the farmers´ stated reasons and risk factors for culling. This observational study used registry data of all cows from herds with ≥20 cow-years in 2013-2015. Cow lactation-level analyses included data of 86,373 primiparous cows from 409 herds and 177,561 lactations of 109,295 multiparous cows from 410 herds. Weibull proportional hazard regression models were used to identify risk factors for culling due to slaughter or death.Results The overall culling rate of Estonian dairy cows was 26.24 (95% CI 26.02; 26.46) per 100 cow-years. The most common farmers´ stated reasons for culling were feet/claw disorders (26.4%), udder disorders (22.6%), metabolic and digestive disorders (18.1%) and fertility problems (12.5%). Animal-level risk factors for culling were Holstein breed, older parity, lower milk yield breeding value, older age at first calving, longer previous calving interval, having assisted calving, stillbirth and birth of twins/triplets. Lower milk yield, somatic cell count over 200,000 cells/ml and fat/protein ratio over 1.5 at first test-milking after calving were associated with greater culling hazard during the lactation. Cows from larger herds, herds with decreasing size and higher milk yields had higher culling probability.Conclusions This study emphasises the need for improved management of hoof health and prevention of mastitis and metabolic diseases. It is essential to ensure easy calving and good health of cows around calving in order to lower the culling hazard.

A Front-Line and Cost-Effective Model for the Assessment of Service Life of Network Pipes

In any water utility, a reliable assessment of the service life of the network pipes is a key piece within the big puzzle of assets management. This paper presents a new statistical model (basic pipes life assessment, BPLA) to assess the service life of pipes, to locate the pipes on the failures bath curve and to forecast the expected failures in future years. Its main novelties are the processing of pipe information (is that information what is adapted to the classical maintenance engineering and not the other way back) and the definition of two different time variables that can be analyzed in parallel. The first novelty makes the model less demanding in terms of data and software tools than others currently available, and the second one allows to get all the results after one single stage of calculation. To show its usability, the BPLA has been applied to a pipe network that supplies water to 500,000 citizens for which two years of failure records are available. Procedures and results have been compared to the well-known Weibull proportional hazard model (WPHM), with final relative errors lower than 10% and 15% on each particular result.

Dairy Cow Culling - Reasons And Risk Factors

Background Culling is a major cost for dairy farms but also an essential part in managing herd productivity. The study aimed to identify the culling rates of Estonian dairy cows, identify the farmers´ stated reasons and risk factors for culling. This observational study used registry data of all cows from herds with ≥20 cow-years in 2013-2015. Cow lactation-level analyses included data of 86,373 primiparous cows and 177,561 lactations of 109,295 multiparous cows. Weibull proportional hazard regression models were used to identify risk factors for culling due to slaughter or death. Results The overall culling rate of Estonian dairy cows was 26.24 (95% CI 26.02; 26.46) per 100 cow-years. The most common farmers´ stated reasons for culling were feet/claw disorders (26.4%), udder disorders (22.6%), metabolic and digestive disorders (18.1%) and fertility problems (12.5%). Animal-level risk factors for culling were Holstein breed, older parity, lower milk yield breeding value, older age at first calving, longer previous calving interval, having assisted calving, stillbirth and birth of twins/triplets. Lower milk yield, somatic cell count over 200,000 cells/ml and fat/protein ratio over 1.5 at first test-milking after calving were associated with greater culling hazard during the lactation. Cows from larger herds, herds with decreasing size and higher milk yields had higher culling probability. Conclusions This study emphasises the need for improved management of hoof health and prevention of mastitis and metabolic diseases. It is essential to ensure easy calving and good health of cows around calving in order to lower the culling hazard.

Relationship between somatic cell score and longevity of Holstein cows in Brazil using a piecewise Weibull proportional-hazard model

The objective of the present work was to evaluate the effect of somatic cell score on the longevity of Holstein cows raised all over Brazil, using a piecewise Weibull proportional-hazard model. The following two longevity traits were defined: true longevity, number of days from first calving to culling; and functional longevity, approximated by correcting true longevity to within-herd-year production. Records on productive life of 131330 cows were used. The model included the time-independent effect of age at first calving. The other effects were time-dependent, and included the following: region by year of calving, variation in herd-size class, milk-production class by year of calving within herd, within-herd milk-production class by number of lactations, within-herd fat content, within-herd protein content, and somatic cell score (SCS). The overall mean of the somatic cell counts (SCC) was 322000 cells/mL. The highest SCC mean was found between 130 to 290 days of lactation. The SCC mean decreased over the years. Cows from Region 5 (Rio Grande do Sul) showed higher SCC means. The risk of culling was slightly higher for functional longevity than for true longevity. The impact of longevity was high in cows from first to fourth lactation with a high SCS, with the risk of culling varying from 0.90 (true longevity: second lactation and Class 2) to 1.2 (functional longevity: fourth lactation and Class 5). Cows at the fifth lactation with a lower SCS had a higher risk of culling (1.4). Including the effect of SCS class by stage of lactation in the models was not beneficial. The decrease in SCS, especially from the first to fourth lactation, can be used for indirect selection to improve the longevity of Holstein cows in Brazil.