Indicators of dairy cow welfare are important for the future assessment and improvement of cow welfare on-farm. The objective of this study was to investigate three categories of non-invasive physiological parameters as potential indicators of welfare in dairy cows, namely cumulation of cortisol in the hair, variability in heart rate (HRV), and variability and composition of milk yield, while taking personality traits into account. These indicators were assessed when cows (all primiparous; n = 48) were housed under reference conditions and when exposed to either improving or worsening housing conditions (weekly changes over the course of six weeks). The worsening housing led to an increase in heart rate and a decrease in milk yield. The housing effects on HRV and other milk-derived indicators, however, were affected by the personality traits of activity, fearfulness and sociability. Less active cows, less fearful cows and less social cows all displayed increases in HRV in the improving housing, but more active cows showed against expectations increased HRV in the worsening housing. More fearful cows showed increases in daily milk fluctuations in the worsening housing. These results point to HRV and milk-derived indicators, the latter of which are often routinely collected and that in addition to being non-invasive are also non-intrusive, as providing interesting physiological indicators of dairy cow welfare which will warrant further research.

The behaviour of an animal is closely linked to its internal state. Various metrics can be calculated from activity data. Complex patterns of activity within or between individuals, such as cyclic patterns and synchrony, can inform on the biological functioning, the health status, or the welfare of an animal. These patterns are now available thanks to sensors that continuously monitor the activity of individual animals over long periods. Data processing and calculations, however, should be clarified and harmonised across studies for the results to be comparable. We present metrics describing activity patterns, we discuss their significance, relevance and limitations for behavioural and welfare studies, and we detail how they can be calculated. Four groups of metrics are distinguished: metrics related to overall activity (e.g., time spent in each activity per unit of time), metrics related to fluctuations around mean activity, metrics related to the cyclicity of activity, and metrics related to the synchrony between animals. Metrics may take statistical approaches (e.g., average and variance) or modelling approaches (e.g., Fourier Transform). Examples are taken essentially from cattle for who individual activity sensors are easily available at present. The calculations, however, can be applied to other species and can be performed on data obtained from sensors as well as visual observations. The present methodological article will help researchers to obtain the most benefit from activity data and will support the decision of which metric can be used to address a given purpose.

VraagstellingIn Nederland worden vleeskalveren doorgaans opgezet op het kalverbedrijf op een leeftijd van ongeveer twee weken.Dit is een leeftijd waarop jonge kalveren qua weerstand kwetsbaar zijn omdat de maternale immuniteit verkregen via antistoffen uit de biest al aan het afnemen is, en de eigen immuniteit nog in opbouw is.Deze kwetsbare periode staat ook wel bekend onder de term 'immunity gap' of immuniteitsgat (Chase et al., 2008; Hulbert en Moisa, 2016).De hypothese bij dit experiment was dat de eigen immuniteit van kalveren die ouder zijn, bijvoorbeeld vier in plaats van twee weken, verder ontwikkeld is waardoor de dieren beter bestand zijn tegen de transitie van het melkveebedrijf naar het kalverbedrijf.Of, met andere

This study aimed to characterize the changes in fecal carriage of Extended-Spectrum β-Lactamase (ESBL) producing Enterobacterales (ESBL-PE) in a single Dutch veal calves. During the rearing period at the Dutch veal farm, a decrease in fecal carriage of cefotaxime-resistant Escherichia coli isolates was observed after 2 weeks at the veal farm, while an increase of cefotaxime-resistant Klebsiella pneumoniae isolates was demonstrated. E. coli and K. pneumoniae were isolated from rectal swabs collected from 110 veal calves in week 2, 6, 10, 18, and 24 after their arrival at the farm. ESBL-PE isolates were selectively cultured and identified by MALDI-TOF. ESBL genes were characterized by RT-PCR, PCRs, and amplicon sequencing. A total of 80 E. coli and 174 K. pneumoniae strains were isolated from 104 out of 110 veal calves. The prevalence of ESBL-E. coli decreased from week 2 (61%) to week 6 (7%), while an unexpected increase in ESBL-K. pneumoniae colonization was detected in week 6 (80%). The predominant ESBL genes detected in E. coli isolates were blaCTX-M-15 and the non-ESBL gene blaTEM-1a, while in K. pneumoniae blaCTX-M-14 gene was detected in all isolates. Four cefotaxime-resistant K. pneumoniae isolates were randomly selected and characterized in deep by transformation, PCR-based replicon typing, and whole-genome sequencing (WGS). The clonal relatedness of a subgroup of nine animals carrying K. pneumoniae ESBL genes was investigated by Multi Locus sequence typing (MLST). In four ESBL-K. pneumoniae isolates, blaCTX-M-14 was located on IncFIIK and IncFIINK plasmid replicons and the isolates were multi-drug resistant (MDR). MLST demonstrated a clonal spread of ESBL-K. pneumoniae ST107. To the best of our knowledge, this is the first study to report a change in fecal carriage of ESBL-PE over time in the same veal calf during the rearing period.

Samenvatting 1 Inleiding 1.1 Aanleiding 1.2 Overwegingen 1.3 Doelstelling 2 Materiaal en methode

The aim of this study was to investigate effects of pre-transport diets, transport durations and transport conditions on immune cell subsets, haptoglobin, cortisol and bilirubin of young calves upon arrival at the veal farm. An experiment was conducted with a 2 × 2 × 2 factorial arrangement with 3 factors: 1) provision of rearing milk or electrolytes at the collection center (CC); 2) transport duration (6 or 18 hours) and 3) transport condition (open truck or conditioned truck). Holstein-Friesian and cross-bred calves were used (N = 368; 18 ± 4 days; 45.3 ± 3.3 kg). Blood samples were collected from calves (N = 128) at the collection center, immediately post-transport (T0) and 4, 24, 48 hours, week 1, 3 and 5 post-transport. Blood was analyzed for cortisol, bilirubin, haptoglobin, IgG and IgM. Moreover, cell counts of neutrophils, lymphocytes, monocytes, basophils and eosinophils were measured in blood samples taken at the collection center and T0. In these same blood samples, different lymphocyte populations were characterized by flow cytometry, including CD14+ cells, NK cells, δγ+ T cells, CD8+ cells, CD4+ cells and CD21+ cells. Calves transported in the conditioned truck had higher amounts of white blood cell count (WBC) (Δ = 1.39 × 109/l; P = 0.01), monocytes (Δ = 0.21 × 109/l; P = 0.04), neutrophils (Δ = 0.93 × 109/l; P = 0.003), than calves transported in the open truck regardless, of pre-transport diet or transport duration. The study showed that transport condition and duration influenced parts of the innate immune system of young veal calves. Cortisol, bilirubin and WBC seemed to be connected by similar underlying mechanisms in relation to transport conditions. However, it is unclear which specific pathways in the immune system of young calves are affected by different transport conditions (e.g. temperature, humidity, draught).

A process of validation assesses the appropriateness and usefulness of a tool for its intended purpose within a specific context. Ideally, the validation of a tool should describe the range of purposes and contexts in which it is appropriate. This generally cannot be done completely. Therefore, when such a wide validation cannot be done, the validation process needs to refer clearly to the purpose of the use of the tool and to which animals it is going to be applied. The technological development has led to an increase in the number of sensors and devices that are available for measuring cattle behaviour. The technical solutions behind the sensors can differ substantially, sensors use accelerometer technology, sound recording or image analysis to mention some, and even within each solution, there is a large amount of factors that can influence the quality of the sensor’s information output or battery capacity. A careful evaluation of the purpose and validation of the outputs from sensors for measuring cattle behaviour is required before use. [...] Many behavioural tests are conducted in different research units. Regardless of the nature and design of the experiment, the basic aspects of a standardised behavioural test must be followed to generate data, which is unambiguous and accurate.

Infectious diseases, particularly bovine respiratory disease (BRD) and neonatal calf diarrhea (NCD), are prevalent in calves. Efficient health-monitoring tools to identify such diseases on time are lacking. Common practice (i.e., health checks) often identifies sick calves at a late stage of disease or not at all. Sensor technology enables the automatic and continuous monitoring of calf physiology or behavior, potentially offering timely and precise detection of sick calves. A systematic overview of automated disease detection in calves is still lacking. The objectives of this literature review were hence: to investigate previously applied sensor validation methods used in the context of calf health, to identify sensors used on calves, the parameters these sensors monitor, and the statistical tools applied to identify diseases, to explore potential research gaps and to point to future research opportunities. To achieve these objectives, systematic literature searches were conducted. We defined four stages in the development of health-monitoring systems: (1) sensor technique, (2) data interpretation, (3) information integration, and (4) decision support. Fifty-four articles were included (stage one: 26; stage two: 19; stage three: 9; and stage four: 0). Common parameters that assess the performance of these systems are sensitivity, specificity, accuracy, precision, and negative predictive value. Gold standards that typically assess these parameters include manual measurement and manual health-assessment protocols. At stage one, automatic feeding stations, accelerometers, infrared thermography cameras, microphones, and 3-D cameras are accurate in screening behavior and physiology in calves. At stage two, changes in feeding behaviors, lying, activity, or body temperature corresponded to changes in health status, and point to health issues earlier than manual health checks. At stage three, accelerometers, thermometers, and automatic feeding stations have been integrated into one system that was shown to be able to successfully detect diseases in calves, including BRD and NCD. We discuss these findings, look into potentials at stage four, and touch upon the topic of resilience, whereby health-monitoring system might be used to detect low resilience (i.e., prone to disease but clinically healthy calves), promoting further improvements in calf health and welfare.

The aim of this study was to investigate effects of different early life transport-related factors on health, behavior, use of medicines and slaughter characteristics of veal calves. An experiment was conducted with a 2 × 2 × 2 factorial arrangement with 3 factors: (1) provision of rearing milk or electrolytes before transport, (2) transport duration (6 or 18 h), and (3) type of vehicle (open truck or conditioned truck). The study included male Holstein-Friesian and cross-bred calves (N = 368; 18 ± 4 days; 45.3 ± 3.3 kg). Data on health status of calves were collected at the collection center and at the veal farm until week 27 post-transport. Behavior of calves was recorded during transport and at the veal farm until week 13 post-transport. Use of herd and individual medical treatments was recorded at the veal farm. The prevalence of loose or liquid manure at the veal farm from day 1 until week 3 post-transport was lower in electrolyte-fed calves transported in the conditioned truck compared to electrolytes-fed calves transported in the open truck or milk-fed calves transported in both the conditioned and open truck (Δ = 11% on average; P = 0.02). In comparison with the open truck, calves transported in the conditioned truck had lower prevalence of navel inflammation in the first 3 weeks post-transport (Δ = 3 %; P = 0.05). More milk-fed calves received individual antibiotic treatments compared to electrolyte-fed calves at the veal farm (P = 0.05). In conclusion, the transport-related factors examined in the present study affected health and behavior of calves in the short-term, but there was no evidence for long-term effects. It remains unknown why no long-term effects were found in this study. Perhaps this absence of transport-related effects was due to multiple use of medical treatments in the first weeks at the veal farm. Alternatively, it might be that the collective effects of the transition from the dairy farm to the veal farm, and of the husbandry conditions during the subsequent rearing period, on the adaptive capacity of calves were so large that effects of individual transport-related factors were overruled.

Due to the increased herd size in the Netherlands, there is need to assess the performance of different grazing systems at high stocking densities. The objective of the current experiment was to assess the effect of two extreme grazing systems, kurzrasen (continuous grazing at 3–5 cm sward height) and strip-grazing at a high stocking rate, on grass production and quality, grass morphology and sward density, root development and load bearing capacity on peat soil. To this end, a two-year grazing trial with four herds of 15 cows on 2 ha each was conducted. Kurzrasen showed 18% lower herbage dry matter production on average compared to strip-grazing. The yield penalty of using a shorter regrowth period under kurzrasen was limited due to the strong response in grass morphology, resulting in a dense and lamina-rich sward. There was a small decline in root density at 10 cm soil depth, but no evidence of a lower root density at 20 cm soil depth for kurzrasen compared to strip-grazing. Sward density was higher for kurzrasen compared to strip-grazing, which had a positive impact on load bearing capacity. This is an important feature on peat soils, where load bearing capacity is often limited.

Goed weiden verlaagt de productiekosten van melk en draagt bij aan het positieve imago van de melkveehouderij. Maar beweiden is wel een vak! Om dit vak beter uit te kunnen oefenen zet het Bouwstenenboek Beweiding nieuwe kennis uit Amazing Grazing op een rij.

In dairy farming, social isolation of cattle is commonly practiced for husbandry procedures such as artificial insemination, claw trimming and at times, for provision of medical treatment. When isolated, cows express physiological and behavioural signs of stress, such as elevated heart rate, hypothalamic-pituitary-adrenocortical activity and increased vocalisation rate. The aim of this study was to examine whether enriching the environment of the isolation pen using both tactile (i.e. an automated grooming brush) and visual (i.e. a mirror) stimulation could alleviate stress induced in socially isolated dairy cows. Eighteen cows (9 lactating and 9 dry cows) were subjected to four isolation conditions of 30 min each; isolation in the presence of a mirror, in the presence of an automated grooming brush, in the presence of both a mirror and an automated grooming brush, and in a non-enriched environment (without brush and mirror) that served as a control condition. Physiological (heart rate and heart rate variability) and behavioural indicators of stress (locomotion, vocalizations, attempts to escape the isolation pen and ear position of the cows) were measured during three phases throughout the isolation period (0-5 min, 10-15 min, 20-25 min). Our results show that, first, the heart rate of cows kept in social isolation, as well as the time cows spent in locomotion and exploration of the pen, decreased throughout the isolation period, regardless of treatment. Second, the presence of an automated grooming brush, a mirror or both an automated grooming brush and mirror in the isolation pen was not associated with reduced indicators of stress (physiological and behavioural measures) compared to the non-enriched environment. The results of our study are not in agreement with the findings of previous studies showing reduced levels of stress among socially isolated heifers/cows kept in the presence of visual enrichment (i.e. mirror/picture of a conspecific), and illustrate the need to further explore practices to reduce stress during social isolation.

In many intensive dairy regions in northwest Europe, a decline in grazing is observed. In the Netherlands, the proportion of dairy cows with access to pasture is declining, as well as the time spent grazing per cow. The decline in grazing is seen as an unwanted trend by many stakeholders and is, thus, under debate amongst dairy farmers, the dairy chain, and society. Therefore, a public–private partnership was initiated to encourage grazing by providing farmers with usable means of improving their grazing systems. The partnership involved stakeholders from the dairy farming community, dairy and feed industry, agrotechnical industries, advisory services, and research. The objective of this partnership was to develop and stimulate technological innovations and management measures that increase fresh grass intake at pasture. The innovation network combined an integrated research approach with farmer working groups and broader stakeholder interactive meetings. The project started with a comprehensive grass intake framework, which was the foundation for exploration of innovations. The framework consisted of six interlinked components: soil, grass growth, grass supply, grass intake, feed supplementation, and cow behavior. In a continuous interactive cycle, strategic choices were made to focus on potentially effective innovations. The use of a public–private partnership to develop usable innovations that encourage grazing practices proven to be a good approach to develop a shared vision among stakeholders. It provided a basis to work together toward innovative practices and to disseminate the outcomes to the foreseen users. The approach succeeded in design concepts for two specific innovations, i.e., weekly grass growth predictions and daily fresh grass intake tracking. We demonstrated that meaningful grazing and fresh grass intake are possible in intensive dairy systems with high stocking rates and high levels of supplementary feeding.

Veal calves undergo many challenges in the early stages of their life. Such challenges, including mixing procedures and transportation of calves to the veal farm, may have a negative influence on growth rate, feed intake, metabolism, immunity and disease susceptibility of calves. As a consequence, many hematological, physiological, metabolic and immunological parameters of stressed calves might be altered on arrival at the veal farm. Some of these response variables might be useful as biomarkers of performance of calves at the veal farm as they might provide information about an ongoing disease process, or may predict future diseases. Biomarkers might be helpful to group and manage calves in different risk categories after arrival. By adopting treatment decisions and protocols on a risk-group or individual basis, it would be possible to improve animal health and reduce both disease incidence and antibiotic use. Moreover, the use of biomarkers might be an economically feasible approach as some of them do not need invasive techniques and others can be measured in blood already taken during routine checks. Previous literature mainly assessed the physiological responses of calves to transportation. However, information on the link between on-farm arrival data and future health and performance of veal calves is limited. This review, therefore, examined a wide range of papers and aimed to identify potential biomarkers of future health and performance.

Inactivity is a vastly understudied behavioural category, which may reflect positive or negative affective states in captive or domesticated animals. Increased inactivity in barren-housed animals, in combination with an increased or decreased interest in stimuli, e.g. novel objects, can indicate boredom or apathy. Another theory is that inactivity is an alternative strategy to stereotypies to cope with sub-optimal conditions. The aim of this study was to further our understanding of inactive behaviours and possible associated negative affective states in intensively raised calves fed different diets. In two separate experiments, Holstein-Friesian veal calves (N = 40 + 160) were fed barren or enriched diets: 1) imposed/restricted diet versus free dietary choice (experiment 1); 2) no additional straw versus ad libitum provision of straw (experiment 2); 3) low versus high solid feed provision (experiment 2); 4) bucket versus automated milk dispenser for milk replacer feeding, with high or low solid feed provision (experiment 2). Inactive behaviours, i.e. experiment 1: lie, idle and sleep; experiment 2: lie idle, stand idle, and sleep, were recorded at two ages (experiment 1: 12 and 26 wk; experiment 2: 15 and 24 wk) using instantaneous scan sampling. In experiment 2, latency to touch two novel objects was recorded at 15 and 24 wk. No differences in inactivity were found between calves with a restricted or free choice diet (experiment 1). However, calves fed the more barren diets in experiment 2 showed more lying idle at 24 wk of age, and calves with no ad libitum straw in particular, showed more standing idle at 24 wk of age (P < 0.05). No differences in latency to touch the novel objects were found. Therefore, although barren diets were generally associated with higher levels of inactivity, we found no support that this inactivity reflected boredom or apathy. Only weak associations were found between inactivity and stereotypies, providing only limited support for the idea that these constitute alternative strategies to cope with sub-optimal conditions.

Deze uitspraak van de Griekse filosoof Heraclites (ca.475 vChr.), vind ik wel passen bij de sector vleeskalveren.De veranderingen in de houderij van vleeskalveren zijn eigenlijk best wel spectaculair.Vandaar deze filosofische uitspraak.Ter illustratie een conclusie uit het rapport van de commissie veehouderijwelzijn dieren (waarin gedragsonderzoekers, de Dierenbescherming en de veehouderijsector vertegenwoordigd waren): "Groepshuisvesting met groepsvoedering lijkt geen goed alternatief voor het huisvesten van vleeskalveren in individuele boxen" (1975).Via discussies over centimeters box breedte in de begin jaren tachtig van de vorige eeuw, waar ik als referendaris vierde klas verslag mocht leggen van het zogenoemde tripartite overleg, is er een transitie geweest naar groepshuisvesting, waarbij ook de voeding met uitsluitend kunstmelk aangevuld is met enig ruwvoer/krachtvoer.Vanuit de voorloperpositie van Nederland is groepshuisvesting nu de norm in de hele Europese Unie.De vleeskalversector moet steeds in het Europese perspectief geplaatst worden.De aanpassingen zijn steeds gevolgd op onderzoek naar plussen en minnen van de beoogde verandering.Groot was dan ook de verbazing in de sector dat de Minister voor landbouw in de Nota Dierenwelzijn ( 2007) aangaf dat kalveren voortaan op een met rubber bedekte bodem moesten worden gehouden.Hiermee was geen ervaring opgedaan en er waren ook geen voorbeelden beschikbaar voor de praktijk.Gelukkig voor de sector kwam de Kamer met een motie die om een grootschalig onderzoek vroeg naar de mogelijkheden en de voor-en nadelen van dergelijke vloeren, alvorens deze voor te schrijven.Met dank aan de financiers, het ministerie van Economische Zaken en het Productschap Vee en Vlees, is een meerjarig onderzoekprogramma opgezet.Met de bereidwillige medewerking van kalverhouders zijn diverse vloersoorten uitgetest in een eerste fase.Met een beperkt aantal vloeruitvoeringen, waaraan de kalveren zelf de voorkeur gaven (methode Welfare Quality), is vervolgens een tweede fase van het onderzoek uitgevoerd

The transition period is a critical phase in the life of dairy cows. Early identification of cows at risk for disease would allow for early intervention and optimization of the transition period. Based on the theory of resilience of biological systems we hypothesize that the level of vulnerability of an individual cow can be quantified by describing dynamical aspects of continuously measured physiological and behavioural variables. To examine the relationship between the risk to develop diseases early in lactation and dynamic patterns of high-resolution, physiological and behavioural data, were continuously recorded in individual cows before calving. Dynamic, quantitative parameters for high-resolution physiological and behavioural measures, continuously acquired during the dry period have predictive value for the risk of cows to develop diseases during the early lactation period. Our results suggest that quantitative parameters derived from sensor data may reflect the level of resilience of individual cows.

Behavioural tests for cattle take time to perform and can be stressful for the animals but are currently the only way of assessing behavioural reactions to fear-causing stimuli in a standardised manner. It may be possible to use behavioural data collected remotely in the home pen environment through the use of activity monitors and robotic milkers to identify fearful cattle without testing. In this study eighty five dairy cows were given a novel arena novel object (NANO) test and 79 of these were also human approach (HAP) tested, both thought to reflect fear. All animals had their activity recorded for 40 days prior to the testing period using a tri-axial accelerometer activity monitor. High numbers of novel object contacts in the test was associated with younger animals with fewer lying bouts per day and were less variable in their lying bout duration (Radj2=0.13, F3,75=4.65, P=0.005). Cows with a higher tolerance for human approach had fewer lying bouts per day, a shorter average standing bout duration and presented themselves to the robot milker more often (Radj2=0.08, F3,69=3.12, P=0.032). Personality traits constructed from a principle components analysis of the observed NANO behaviours were also associated with home pen activity. Cows which scored highly on the first component termed ‘neophobia’ were older, had more lying bouts and a greater variation in the duration of their average lying bout (Radj2=0.15, F3,75=5.32, P=0.002) while cows which scored highly on the second component termed ‘boldness’ were older cows with less variation in their average lying bout duration (Radj2=0.11, F2,75=5.63, P=0.005). To conclude, significant relationships exist between behaviours in short-term personality tests and home pen activity recorded over several weeks. As fearfulness is reflected in spontaneous home pen behaviours, activity databases could be incorporated into models predicting fearfulness and welfare assessment protocols.