Eesti piimalehmade praakimine ja eluiga – loomapõhised, karja nakkuslikud ja loomapidajaga seotud riskitegurid

A Thesis for applying for the degree of Doctor of Philosophy in Veterinary Science.Väitekiri filosoofiadoktori kraadi taotlemiseks loomaarstiteaduse erialal.The milk production of the cows increases every year with an accompanying decrease in their lifespan both in Estonia and other countries around the world. These trends are especially apparent in larger production farms. Intensive culling and early exit from the herd reflect poor cow health and decreased welfare but may also be related to the production goals and attitudes of the farmers. The short productive life of the cows is associated with greater environmental impact and also does not meet consumer expectations. In this thesis the effect of different factors on dairy cow culling and lifespan were analyzed. The animal-based risk, herd infectious and farmer-related risk factors of culling were investigated in Estonian large dairy farms. In the current study we found that the culling rate and longevity of cows in Estonian dairy herds are similar to results of other high production countries. The highest culling risk was related to calving problems and early post-partum period. Also, the risk of culling increased with an age of the dairy cow. The four most common reasons for culling in this study were feet and claw disorders, udder disorders, metabolic and digestive disorders, and fertility problems. Estonian large dairy herds were endemically infected with many cattle pathogens having significant impact on culling and longevity by impairing cattle health, fertility, and production. In this research was found that farm managers are generally not satisfied with the culling rate and longevity of cows. Also, the culling rate was the highest and the longevity of the cows was the shortest precisely in those dairy farms where the farm managers prioritized the achievement of high milk production more than the long life of the cows. A better understanding of the economic return of dairy cow longevity and finding the compromise between milk yields and cow health would be important for the sustainability.Nii Eestis kui mujal maailmas suureneb lehmade piimatoodang igal aastal, kuid samaaegselt väheneb nende eluiga. Eriti märgatavad on need trendid suuremates tootmisfarmides. Intensiivne praakimine ja varajane karjast väljaminek kajastavad lehmade habrast tervist ja vähenenud heaolu, samas võib see olla ka seotud loomapidajate tootmiseesmärkide ja suhtumisega. Lehmade lühike produktiivne eluiga on seotud suuremate keskkonnamõjudega ega vasta ka tarbijate ootustele. Käesoleva väitekirja eesmärk oli analüüsida, millised tegurid mõjutavad lehmade praakimist ja eluiga. Uurisime nii praakimise loomapõhiseid ohutegureid Eesti piimaveise populatsioonis, samuti nakkushaiguste leviku ning loomapidajaga seotud riskitegureid peamiselt suurtes tootmisfarmides. Tuvastasime, et Eesti piimakarjades on lehmade praakimiskordaja ja eluea pikkus sarnane teistele kõrgetoodanguliste riikide näitajatele. Lehmade praakimisrisk oli kõige kõrgem poegimisprobleemide korral. Praakimise tõenäosus oli suurim vahetult pärast poegimist, samuti suurenes see oluliselt vanuse kasvades. Peamisteks Eesti lehmade praakimispõhjusteks on sõra- ja jäsemehaigused, udarahaigused, ainevahetus- ja seedeelundkonna haigused ning sigimisprobleemid. Eesti suured piimakarjad on endeemselt nakatunud mitmete oluliste veiste nakkushaigustega, millest mõnedel on märkimisväärne mõju lehmade praakimisriskile ja eluea pikkusele. Uuringus leidsime, et farmijuhatajad ei ole üldiselt rahul lehmade praakimismäära ja eluea pikkusega. Samas oli praakimiskordaja suurim ja lehmade eluea pikkus lühim just neis ettevõtetes, kus loomapidajad tähtsustasid kõrge piimatoodangu saavutamist enam kui lehmade pikka eluiga. Lehmade karjaspüsivuse parendamiseks tuleks enam panustada karja tervise edendamisse, samuti on vajalik selgitada lehmade pikema eluea majanduslikku kasumlikkust ning leida kompromiss lehmade väljalüpsi ja karjaspüsimise vahel.The publication of this dissertation is granted by the Graduate School in Biomedicine and Biotechnology and by the Estonian University of Life Sciences

Culling reasons and risk factors in Estonian dairy cows

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

Multiblock analysis reveals key areas and risk factors for dairy cow losses

Describe the relative contribution of the production areas (thematic blocks) to cow losses characterized by herd on farm mortality risk (MR), culling rates (CR) and mean age of culled cows (MAofCC). Also, the study aimed to identify within each block, the variables mostly contributing to the cow losses.This work was financed by the Estonian Research Council grant (PSG 268).This work was financed by the Estonian Research Council grant (PSG 268

Attitudes and personality of farm managers and association with cow culling rates and longevity in large-scale commercial dairy farms

The farmer has the central role in determining cow culling policies on their farm and thus affecting cow longevity. The present study aimed to examine farm managers´ satisfaction, attitudes, personality traits and analyse the associations with dairy cow culling and longevity in large commercial dairy farms. Farm managers of 116 dairy herds rearing at least 100 cows in freestall barns were included. A questionnaire for the farm managers registered personal background information of respondent and included statements capturing their satisfaction, opinions and attitudes regarding dairy cow culling and longevity, farming in general, and a Ten Item Personality Inventory scoring. For each herd, the last 12 months cow culling rate (CR, excluding dairy sale) and herd mean age of culled cows (MAofCC) was obtained from the Estonian Livestock Performance Recording Ltd. A K-mean clustering algorithm was applied to subgroup farm managers based on their attitudes, opinions and personality traits. The yearly mean herd CR was 33.0% and MAofCC was 60.6 months. Farm managers´ were mostly dissatisfied with cow longevity and culling rates in their farms. Dissatisfaction with culling rates and longevity, priority for producing high milk yields over longevity and production-oriented attitude was associated with high culling rates and poor longevity. Farm managers' personality had an effect on herd culling rates and their attitudes explained one third of the variability of culling rates and longevity.Explaining the economic consequences of high culling rates and decreased longevity, improving the visibility of these parameters together with benchmarking could bring these issues into focus

Attitudes and personality of farm managers and association with cow culling rates and longevity in large-scale commercial dairy farms

The farmer has the central role in determining cow culling policies on their farm and thus affecting cow longevity. The present study aimed to examine farm managers satisfaction, attitudes, personality traits and analyse the associations with dairy cow culling and longevity in large commercial dairy farms.Farm managers of 116 dairy herds rearing at least 100 cows in freestall barns were included. A questionnaire for the farm managers registered personal background information of respondent and included statements capturing their satisfaction, opinions and attitudes regarding dairy cow culling and longevity, farming in general, and a Ten Item Personality Inventory scoring. For each herd, the last 12 months cow culling rate (CR, excluding dairy sale) and herd mean age of culled cows (MAofCC) was obtained from the Estonian Livestock Performance Recording Ltd. A K-mean clustering algorithm was applied to subgroup farm managers based on their attitudes, opinions and personality traits.The yearly mean herd CR was 33.0% and MAofCC was 60.6 months. Farm managers acute accent were mostly dissatisfied with cow longevity and culling rates in their farms. Dissatisfaction with culling rates and longevity, priority for producing high milk yields over longevity and production-oriented attitude was associated with high culling rates and poor longevity. Farm managers' personality had an effect on herd culling rates and their attitudes explained one third of the variability of culling rates and longevity.Explaining the economic consequences of high culling rates and decreased longevity, improving the visibility of these parameters together with benchmarking could bring these issues into focus