E.A.M. Bokkers

Invited review: Associations between variables of routine herd data and dairy cattle welfare indicators

As farm animal welfare is high on the political and societal agendas of many countries, considerable pressure exists to establish audit programs in which farm animal welfare is routinely monitored. On-farm assessment of animal welfare, however, is time-consuming and costly. A promising strategy to monitor animal welfare more efficiently is to first estimate the level of animal welfare on a farm based on routine herd data that are available in national databases. It is not currently known which variables of routine herd data (VRHD) are associated with dairy cattle welfare indicators (WI). Our aim was to identify VRHD that are associated with WI in a literature review. The 27 VRHD used in this review included the main types of data that are currently collected in national herd databases of developed countries, and related to identification and registration, management, milk production, and reproduction of dairy herds. The 34 WI used in this review were based on the Welfare Quality Assessment Protocol for Cattle. The search yielded associations in 146 studies. Twenty-three VRHD were associated with 16 WI. The VRHD that related to milk yield, culling, and reproduction were associated with the largest number of WI. Few associations were found for WI that referred to behavioral aspects of animal welfare, nonspecific disease symptoms, or resources-based indicators. For 18 WI, associations with VRHD were not significant (n=5 WI) or no studies were found that investigated associations with VRHD (n=13 WI). It was concluded that many VRHD have potential to estimate the level of animal welfare on dairy farms. As strengths of associations were not considered in this review, however, the true value of these VRHD should be further explored. Moreover, associations found at the animal level and in an experimental setting might not appear at the farm level and in common practice and should be investigated. Cross-sectional studies using integrated welfare scores at the farm level are needed to more accurately determine the potential of VRHD to estimate levels of animal welfare on dairy farms.

Activity, oral behaviour and slaughter data as welfare indicators in veal calves: a comparison of three housing systems

Abstract A study was conducted to compare activity, oral behaviour and slaughter data of veal calves kept in three different housing systems: (1) individual housing (IH) where calves are kept in individual crates; (2) group housing (GH) where calves are kept in individual crates during the first 8 weeks and thereafter in groups of five to seven individuals, and (3) Peters Farm ® (PF) a housing system where calves are kept in large groups fed via an automatic feeding station. Six commercial farms with Holstein–Friesian bull calves for each housing system were selected ( n =18). Behavioural observations were done at weeks 2, 3, 6, 12 and 24 after arrival of the calves at the farm to measure time budget in the morning and 30min after feeding, and 24h activity. All farms were assessed by the animal needs index (ANI) at week 12. The 24h activity pattern of calves in IH and in GH showed peaks around feeding time. The activity of calves in PF was distributed equally over the day. Calves in PF were standing less and lying more ( P P P P P P Overall, the measured parameters gave some indication that welfare has improved in PF during the first 6 weeks of life. At a later age, these parameters indicated that in PF a similar welfare existed as in IH and GH. Food but not housing conditions seems to be the determinative factor at that age. IH and GH were not different for many parameters.

Working for food under conditions of varying motivation in broilers

Broiler chickens, Gallus gallus domesticus, have been selected for rapid weight gain and appear to be continously hungry. If this is so, then energy that broilers invest in obtaining food should be insensitive to their level of feed restriction. We tested this hypothesis by measuring the maximum price (i.e. maximum number of key pecks) broilers with different body weights would pay for a food reward under conditions of varying feed restriction. Two groups of 20 broilers were fed on 50 or 75% of the amount of feed a broiler would eat when fed ad libitum. Broilers were able to learn an operant task and were willing to work for food. Birds of the 50%-group paid a higher maximum price for a food reward and responded more quickly to food presentation than the birds of the 75%-group in the first test week and showed a nonsignificant tendency to pay a higher price and to respond more quickly in the second test week. Different levels of long-term feed restriction had an influence on their body weight and on their motivation to work for food. No short-term effect of changing feed restriction was found. Birds showed frustration behaviour after the last food reward had been obtained, indicating that they were still hungry. The results indicate that broilers are still sensitive to different levels of feed restriction and that they can balance their investments and profits to a certain extent.

Methods for uncertainty propagation in life cycle assessment

Life cycle assessment (LCA) calculates the environmental impact of a product over its entire life cycle. Uncertainty analysis is an important aspect in LCA, and is usually performed using Monte Carlo sampling. In this study, Monte Carlo sampling, Latin hypercube sampling, quasi Monte Carlo sampling, analytical uncertainty propagation and fuzzy interval arithmetic were compared based on e.g. convergence rate and output statistics. Each method was tested on three LCA case studies, which differed in size and behaviour. Uncertainty propagation in LCA using a sampling method leads to more (directly) usable information compared to fuzzy interval arithmetic or analytical uncertainty propagation. Latin hypercube and quasi Monte Carlo sampling provide more accuracy in determining the sample mean than Monte Carlo sampling and can even converge faster than Monte Carlo sampling for some of the case studies discussed in this paper. Display Omitted

Inter- and intra-observer reliability of experienced and inexperienced observers for the Qualitative Behaviour Assessment in dairy cattle

Qualitative Behaviour Assessment (QBA) is part of the Welfare Quality® protocol for dairy cattle, although its inter- and intra-observer reliability have not been reported. This study evaluated inter- and intra-observer reliability of the QBA for dairy cattle in experienced and inexperienced observers using videos. Eight experienced observers performed the QBA (20 descriptors) twice for 16 video clips (60 s per clip; series 1) showing 4-17 animals. They assessed another 11 video clips showing herds (4 shots of 30 s per clip; series 2). Ten inexperienced observers performed the QBA on both video series one time. Inter-observer reliability of experienced observers ranged from slight to moderate (both assessments of series 1), and from low to high (series 2) for descriptors, and from slight to moderate for the QBA score. Inter-observer reliability of inexperienced observers ranged from low to moderate (series 1), and from low to high (series 2) for descriptors, and was moderate (both series) for the QBA score. Intra-observer correlations varied largely per descriptor and observer. They were both negative and positive, and ranged from low to very high. High correlations, however, were not necessarily associated with low paired differences. Values of half of the descriptors and the QBA score differed amongst experienced and inexperienced observers. The QBA appears insufficiently reliable as a tool for welfare assessment in dairy cattle.

Economic, ecological, and social performance of conventional and organic broiler production in the Netherlands

1. In this study, we compared a conventional broiler production system keeping fast growing broilers with an organic broiler production system keeping slow growing broilers in the Netherlands, both managed by one person working a full time year (Full Time Equivalent, FTE). This comparison was based on a quantification of economic, ecological and social indicators. Indicators were quantified using scientific literature and national data sets. 2. The organic system performed better for the economic indicator net farm income per FTE than the conventional system. 3. Regarding ecological indicators, calculations showed a higher on-farm emission of ammonia per kg live weight for the organic system. Moreover, an organic system includes a higher risk for eutrophication per ha due to outdoor access. Emission of green house gasses, use of fossil fuels and use of land required for the production of one kg of live weight is higher for an organic than for a conventional system. This is mainly due to a lower feed conversion in organic production and use of organic feed. 4. The organic system performed better than the conventional system for the social indicators related to animal welfare time spent on walking, footpad lesions, mortality, and sound legs. Regarding the social indicator food safety was found that meat from an organic system contained less antibiotic residues and Salmonella contaminations but more Campylobacter contaminations than meat from a conventional system. 5. Changing from a conventional to an organic broiler production system, therefore, not only affects animal welfare, but also affects economic, ecological and other social issues. In this study, we ran into the situation that some information needed was lacking in literature and quantifications had to be based upon several sources. Therefore, an integrated on-farm assessment is needed, which can be used to develop a broiler production system that is economically profitable, ecologically sound, and acceptable for society.

Motivation and ability to walk for a food reward in fast- and slow-growing broilers to 12 weeks of age

Poor physical abilities of broilers may prevent them from performing behaviours for which they are motivated. The aim of this study was to measure the influence of physical ability and motivation on the performance of broilers in short physical tasks. We tested birds from a fast- and a slow-growing broiler strain in a runway to 12 weeks of age. To manipulate motivation, half of the birds of each strain was feed deprived for 3h and the other half for 24h before testing. Each bird was tested in a control and a slalom runway test once a week. With a similar motivation, slow growers had a shorter latency to start walking and walked faster through the runway than fast growers in both tests. In fast growers walking speed decreased faster with age than in slow growers. Slow growers vocalised more in both tests. In the slalom test, 24h deprived birds vocalised more than 3h deprived birds. Although the fast and slow growers have a different genetic background, the results indicated that motivation is the dominant determinative factor for walking in birds with a low body weight, while physical ability is the dominant determinative factor for walking in birds with a high body weight.

Prevalence of gastrointestinal disorders recorded at postmortem inspection in white veal calves and associated risk factors

The study aimed at assessing the prevalence of poor rumen development, presence of rumen plaques, rumen papillae hyperkeratinization, and abomasal lesions in veal calves and to investigate risk factors for their occurrence at the farm level. Within a wide cross-sectional study, a sample of 170 veal farms representative of the European veal meat production systems was considered in the 3 major producing countries (99 in the Netherlands, 47 in France, and 24 in Italy). An average of 59 ± 10 (SD) rumens and abomasa belonging to calves from a single batch per farm were inspected at the abattoir by trained observers to assess the incidence of these gastrointestinal disorders. Potential risk factors for their occurrence related to farm management, housing, and to the feeding plan were obtained by a questionnaire submitted to the stockperson. Prevalence of poor rumen development (almost no papillae present), rumen plaques, and hyperkeratinization were 60.4, 31.4, and 6.1% of rumens, respectively, whereas abomasal lesions in the pyloric area were recorded in 74.1% of abomasa. Independent variables related to the feeding system confirmed to be the main risk factors for the occurrence of gastrointestinal disorders in veal calves. However, additional risk sources for each given problem were identified among housing and management variables. The provision of a low amount of solid feed (≤ 50kg of dry matter/head per cycle) was a relevant risk for rumen underdevelopment. Rumen wall alterations (plaques and hyperkeratinization) and abomasal lesions were instead associated with the administration of large quantities of solids (151-300 kg of dry matter/head per cycle) in calves receiving milk replacer during the entire fattening cycle. Among the types of solid feed, cereal grain acted as a preventive measure for low rumen development, whereas it was a risk factor for the occurrence of rumen plaques, papillae hyperkeratinization, and abomasal lesions. Some housing and management options adopted to improve veal calf welfare (i.e., higher space allowance and use of heating) were associated with lower risk for gastrointestinal disorders.

Prevalence of respiratory disorders in veal calves and potential risk factors

The study aimed to assess the in vivo and postmortem prevalence of respiratory disorders in veal calves and investigate risk factors associated with them. A cross-sectional study was carried out in 174 farms in the 3 major veal meat-producing countries in Europe (50 in France, 100 in the Netherlands, and 24 in Italy). Trained veterinarians visually evaluated individual calves of 1 batch per farm at 3 and 13 wk after arrival and at 2 wk before slaughter to assess the prevalence of hampered respiration, nasal discharge, and coughing. A random sample of lungs belonging to calves of the same batch was monitored at the slaughterhouse for mild to moderate or severe signs of pneumonia, and presence of pleuritis. Data regarding veal calf housing, feeding, and management and specific characteristics of the batch were collected through an interview with the stockperson, and the potential of these as respiratory disease risk factors was assessed. Regardless of the stage of fattening, the prevalence of in vivo signs of respiratory disorders in calves was always <7%. This low prevalence was likely the outcome of the general implementation by veal producers of standardized practices such as prophylaxis, all-in/all-out, and individual daily checks of the calves, which are recognized tools for effective disease prevention and management. However, at postmortem inspection, 13.9% and 7.7% of lungs showed mild to moderate and severe signs of pneumonia, respectively, and 21.4% of the inspected lungs had pleuritis. Thus, even mild clinical signs of respiratory disorder in calves at specific time points during the fattening period may be associated with high prevalence of lungs with lesions at slaughter. Alternatively, clinical symptoms recorded during routine visual inspections of veal calves on-farm may be poor predictors of the true prevalence of respiratory disease in calves. Among all potential risk factors considered, those concerning the characteristics of the batch were predominant but factors related to housing, management and feeding equipment were also relevant. Different risk factors were involved at different stages of the fattening period. Therefore, to overcome respiratory disorders in veal calves, different solutions may apply to different stages of the fattening period.

Manual and automatic locomotion scoring systems in dairy cows: A review

The objective of this review was to describe, compare and evaluate agreement, reliability, and validity of manual and automatic locomotion scoring systems (MLSSs and ALSSs, respectively) used in dairy cattle lameness research. There are many different types of MLSSs and ALSSs. Twenty-five MLSSs were found in 244 articles. MLSSs use different types of scale (ordinal or continuous) and different gait and posture traits need to be observed. The most used MLSS (used in 28% of the references) is based on asymmetric gait, reluctance to bear weight, and arched back, and is scored on a five-level scale. Fifteen ALSSs were found that could be categorized according to three approaches: (a) the kinetic approach measures forces involved in locomotion, (b) the kinematic approach measures time and distance of variables associated to limb movement and some specific posture variables, and (c) the indirect approach uses behavioural variables or production variables as indicators for impaired locomotion. Agreement and reliability estimates were scarcely reported in articles related to MLSSs. When reported, inappropriate statistical methods such as PABAK and Pearson and Spearman correlation coefficients were commonly used. Some of the most frequently used MLSSs were poorly evaluated for agreement and reliability. Agreement and reliability estimates for the original four-, five- or nine-level MLSS, expressed in percentage of agreement, kappa and weighted kappa, showed large ranges among and sometimes also within articles. After the transformation into a two-level scale, agreement and reliability estimates showed acceptable estimates (percentage of agreement ≥ 75%; kappa and weighted kappa ≥ 0.6), but still estimates showed a large variation between articles. Agreement and reliability estimates for ALSSs were not reported in any article. Several ALSSs use MLSSs as a reference for model calibration and validation. However, varying agreement and reliability estimates of MLSSs make a clear definition of a lameness case difficult, and thus affect the validity of ALSSs. MLSSs and ALSSs showed limited validity for hoof lesion detection and pain assessment. The utilization of MLSSs and ALSSs should aim to the prevention and efficient management of conditions that induce impaired locomotion. Long-term studies comparing MLSSs and ALSSs while applying various strategies to detect and control unfavourable conditions leading to impaired locomotion are required to determine the usefulness of MLSSs and ALSSs for securing optimal production and animal welfare in practice.