Histologically validated scoring system for the assessment of hock burn in broilers.

The assessment of bird-based welfare indicators plays an important role in the evaluation of bird welfare. The aim of the study was to histologically validate a visual scoring system for hock burn in broilers and to detect threshold values of a visual score to define welfare-relevant alterations in terms of mild lesions or ulcers of the hock. We collected 200 hocks of 39- to 42-day-old Ross 308 broilers after the slaughter process. Each hock was scored visually ("macro scores" 0-4) and evaluated histologically ("micro scores" 0-3), with high scores representing more severe lesions. Although we found a tendency for higher micro scores with increasing macro scores, an exact allocation of macro to micro scores was not possible. For example, macro score 1 could represent micro scores 1, 2 and 3, whereas macro scores 3 and 4 always represented micro score 3 (ulcer). The conditional probability of certain micro scores for given macro scores was estimated using a multinomial logistic regression model. Ulcer showed the highest probability at macro score 1, whereas mild lesions were not found to have an estimated highest probability at any macro score. The depth of inflammation of hock burn lesions increased with increasing macro scores up to macro score 3 with an average depth of 1019 µm. Visually more severe and deeper lesions were also histologically rated with higher scores. Thus, considering limitations, the herein validated macroscopic assessment scheme for hock burn allows an estimation of histological alterations in hocks of broilers.RESEARCH HIGHLIGHTS Histological validation of a visual assessment scheme for hock burn in broilers.Tendency for higher micro scores with increasing macro scores.Estimation of histological score via macro score possible with limitations.Histological depth of inflammation increased with an increasing macro score.

Specific bioactive collagen peptides (PETAGILE® ) as supplement for horses with osteoarthritis: A two-centred study.

The aim of the study was to evaluate the clinical efficacy of specific bioactive collagen peptides (BCP), here administered orally as PETAGILE® , on horses with mild to moderate, naturally occurring osteoarthritis. Data from a two-centred pilot study were used for the meta-analysis. Thirty-eight privately owned horses of various breeds were available. In one centre, 18 of these patients (6 ± 3 years; 519 ± 100 kg BW) received either 25 g (n = 6) or 50 g (n = 12) BCP/day orally for 12 weeks. In the second centre, 20 horses (18 ± 4 years; 413 ± 94 kg BW) received either a placebo (control; n = 10) or 25 g BCP/day. The attending veterinarians performed an orthopaedic examination including flexion tests and evaluated the degree of lameness, rotation pain, step length and arc of foot flight during trot (8 parameters) at the beginning and after 6 and 12 weeks. The horse owners answered a weekly questionnaire about their perception of lameness, mobility and the horses' willingness to run. In the 50 g BCP group, in six of eight parameters, a strong effect (Cohen's r > .5) was detected with two parameters (lameness and flexion pain) significantly improved already after 6 weeks. In the 25 g BCP group, a moderate effect (Cohen's r = .3-0.5) was seen in six parameters, with three parameters improved already after 6 weeks. The owners reported a strong effect for mobility and willingness to run (Cohen's r = .69 and .62, respectively) and a moderate effect (Cohen's r = .49 and 0.41) for the development of lameness in the 50 g and 25 g BCP group in comparison with the placebo treatment. This study revealed promising effects of the safe oral-specific BCP supplementation on symptoms of osteoarthritis in horses already after 3 months. The higher dosage of 50 g BCP/day had superior impact. Further long-term investigations on specific BCP efficacy in horses with osteoarthritis, preferably in blinded and placebo-controlled studies, should be performed to confirm these first positive results.

Development of a prognostic tool for the occurrence of feather pecking and cannibalism in laying hens.

In July 2015, a German voluntary decree stipulated that the keeping of beak-trimmed laying hens after the 1st of January 2017 will no longer be permitted. Simultaneously, the present project was initiated to validate a newly developed prognostic tool for laying hen farmers to forecast, at the beginning of a laying period, the probability of future problems with feather pecking and cannibalism in their flock. For this purpose, we used a computer-based prognostic tool in form of a questionnaire that was easy and quick to complete and facilitated comparisons of different flocks. It contained various possible risk factors that were classified into 3 score categories (1 = "no need for action," 2 = "intermediate need for action," 3 = "instant need for action"). For the validation of this tool, 43 flocks of 41 farms were examined twice, at the beginning of the laying period (around the 20th wk of life) and around the 67th wk of life. At both visits, the designated investigators filled out the questionnaire and assessed the plumage condition and the skin lesions (as indicators of occurrence of feather pecking and cannibalism) of 50 laying hens of each flock. The average prognostic score of the first visit was compared with the existence of feather pecking and cannibalism in each flock at the end of the laying period. The results showed that the prognostic score was negatively correlated with the plumage score (r = -0.32; 95% confidence interval [CI]: [-0.56; -0.02]) and positively correlated with the skin lesion score (r = 0.38; 95% CI: [0.09; 0.61]). These relationships demonstrate that a better prognostic score was associated with a better plumage and skin lesion score. After performing a principal component analysis on the single scores, we found that only 6 components are sufficient to obtain highly sensitive and specific prognostic results. Thus, the data of this analysis should be used for creating applicable software for use on laying hen farms.

Evaluation of welfare parameters in laying hens on the basis of a Bavarian survey.

Health issues like infestation with poultry red mite (Dermanyssus gallinae) and behavioral problems such as feather pecking and cannibalism are reported as current problems on laying hen farms. However, the epidemiological prevalence of these issues in Bavaria, Germany, is not known. The objective of the present survey was to determine the epidemiological prevalence of health and behavioral parameters and the management of hen farms in practice. The survey was sent to all laying hen farmers with more than 1,000 hens in Bavaria, Germany, and contained questions regarding flock management, behavior problems and health issues. The response rate was 40.8% and surveys were answered regarding 293 individual flocks on 147 farms. Three-quarters (77.6%) of the respondents housed their hens under conventional conditions. Farming system had an influence (P ≤ 0.05) on several management measures and the hens' behavior. An infestation of the flocks with poultry red mite was stated in 65.7%, whereby a relationship existed with the farming system (P = 0.001) and the provision of an additional dust bath (P ≤ 0.001). The occurrence of feather pecking (18.5%) was related with the farming system (P = 0.001), the presence of roosters (P = 0.034), the locking of laying hens into the aviary (P = 0.006), not allowing access to the entire litter space after housing (P = 0.044) and nervous (P = 0.002) or chasing behavior (P ≤ 0.001) of laying hens. Similarly, cannibalism (15.0%) was related with locking hens into the aviary system (P ≤ 0.001) and not allowing access to the entire litter space (P = 0.026). According to these results, farmers should avoid locking the hens into the aviary or not allowing access to the entire litter space, because these measures relate to nervous behavior that may result in feather pecking or cannibalism. The provision of an additional dust bath is one of the management measures that can positively influence hens' health and behavior.

Dust-bathing behavior of laying hens in enriched colony housing systems and an aviary system.

The dust-bathing behavior of Lohmann Selected Leghorn hens was compared in 4 enriched colony housing systems and in an aviary system. The enriched colony housing systems differed especially in the alignment and division of the functional areas dust bath, nest, and perches. Forty-eight-hour video recordings were performed at 3 time-points during the laying period, and focal animal sampling and behavior sampling methods were used to analyze the dust-bathing behavior. Focal animal data included the relative fractions of dust-bathing hens overall, of hens bathing in the dust-bath area, and of those bathing on the wire floor throughout the day. Behavior data included the number of dust-bathing bouts within a predefined time range, the duration of 1 bout, the number of and reasons for interruptions, and the number of and reasons for the termination of dust-bathing bouts. Results showed that the average duration of dust bathing varied between the 4 enriched colony housing systems compared with the aviary system. The duration of dust-bathing bouts was shorter than reported under natural conditions. A positive correlation between dust-bathing activity and size of the dust-bath area was observed. Frequently, dust baths were interrupted and terminated by disturbing influences such as pecking by other hens. This was especially observed in the enriched colony housing systems. In none of the observed systems, neither in the enriched colony housing nor in the aviary system, were all of the observed dust baths terminated "normally." Dust bathing behavior on the wire mesh rather than in the provided dust-bath area generally was observed at different frequencies in all enriched colony housing systems during all observation periods, but never in the aviary system. The size and design of the dust-bath area influenced the prevalence of dust-bathing behavior in that small and subdivided dust-bath areas reduced the number of dust-bathing bouts but increased the incidence of sham dust bathing on the wire mesh.