Experienced and inexperienced observers achieved relatively high within-observer agreement on video mobility scoring of dairy cows.

Assessment of lameness prevalence and severity requires visual evaluation of thelocomotion of a cow. Welfare schemes including locomotion assessments are increasingly being adopted, and more farmers and their veterinarians might implement a locomotion-scoring routine together. However, high within-observer agreement is a prerequisite for obtaining valid mobility scorings, and within-observer agreement cannot be estimated in a barn, because the gait of cows is dynamic and may change between 2 occasions. The objective of this study was to estimate the within-observer agreement according to the observers' educational background and experience with cattle, based on video recordings with very diverse types of gait. Groups of farmers, bovine veterinarians, first- and fourth-year veterinary students, researchers, and cattle-inexperienced sensory assessors evaluated mobility using a 5-point mobility score system developed specifically for walking cows (n=102 observers). The evaluation sessions were similar for all groups, lasted 75 min, and were organized as follows: introduction, test A, short training session, break, and test B. In total, video recordings of 22 cows were displayed twice in a random order (11 cows in each test × 2 replicates). Data were analyzed applying kappa coefficient, logistic regression, and testing for random effects of observers. The crude estimates of 95% confidence interval for weighted kappa in test A and B ranged, respectively, from 0.76 to 0.80 and 0.70 to 0.75. When adjusting for the fixed effects of video sample and gait scoring preferences, the probability of assigning the same mobility score twice to the same cow varied from 55% (sensory assessors) to 72% (fourth-year veterinary students). The random effect of the individual observers was negligible. That is, in general observers could categorize the mobility characteristics of cows quite well. Observers who preferred to assess the attributes back arch or the overall mobility score (based on uneven gait) had the highest agreement, respectively, 69 or 68%. The training session seemed insufficient to improve agreement. Nonetheless, even novice observers were able to achieve perfect agreement up to 60% of the 22 scorings with merely the experience obtained during the study (introduction and training session). The relatively small differences between groups, together with a high agreement, demonstrate that the new system is easy to follow compared with previously described scoring systems. The mobility score achieves sufficiently high within-observer repeatability to allow between-observer agreement estimates, which are reliable compared with other more-complex scoring systems. Consequently, the new scoring scale seems feasible for on-farm applications as a tool to monitor mobility within and between cows, for communication between farmers and veterinarians with diverse educational background, and for lamenessbenchmarking of herds.

The effect of breed and feed-type on the sensory profile of breast meat in male broilers reared in an organic free-range system.

1. Studies on the sensory profiling of male broiler breast meat were carried out to evaluate the effect of two very different broiler breeds (JA757 and New Hampshire), two different feed types (broiler and grower feed) and age at slaughter (82 and 110 d). 2. The sensory profiling consisted of a pilot study, 4 training sessions, and finally the assessment. During the training session a panel of 9 assessors defined 17 attributes, which were used to describe the smell, texture and flavour of the breast fillets. Each attribute was evaluated on a 15-cm unstructured line scale. 3. The breast meat became significantly less hard, and more juicy and tender in the New Hampshire at 110 d of age, whereas the opposite was found in JA757, which also acquired a more "sourish" flavour with age. The smell of "sweet/maize" and "bouillon" became weaker with age in JA757, but not in New Hampshire. 4. Several significant differences in relation to the main factors of breed and age were found. The traditional broiler hybrid JA757 did best for most smell and flavour attributes, whereas New Hampshire did best for the texture attributes. Age had a negative effect on the flavours and smell attributes "fresh chicken", "neck of pork" and "sweet maize", but a positive effect on the texture attribute "crumbly". In addition meat was more "stringy" at 110 d of age. 5. The flavours "neck of pork" and "umami" were significantly improved when JA757 was fed on the broiler feed and when New Hampshire was given the grower feed. The meat smelt more "sourish" at 82 d of age and less "sourish" at 110 d of age when the grower feed was consumed. Meat was significantly harder and stringier when JA757 was fed on the grower feed. This was not the case for New Hampshire. In general, the meat was significantly less crumbly and stringier with the grower feed. 6. Overall a very distinct difference in sensory profile was found between the two breeds. In addition different slaughter ages and feeding strategies should be taken into consideration in a niche production based on alternative genotypes.