Structuring Broiler Barns: How a Perforated Flooring System Affects Animal Behavior.

Broiler chickens in Europe are usually raised in a barren environment. Elevated perforated platforms address this problem and can positively influence animal health and welfare. To evaluate the effect of an elevated perforated floor on the behavior of broiler chickens, one of two barns was equipped with a perforated flooring system under the food and water supply. The second barn was used as a control. In total, three fattening periods were observed, with 500 broiler chickens (Ross 308 breed) kept in each barn. To compare the behavior of the birds in these groups, cameras were installed in the two barns. The videos were analyzed by counting the number of birds and observing focal animals while recording their behavior. More animals were observed on the perforated floor than in the littered control area (p < 0.001), but focal animals spent less time on the perforated floor compared to the observed littered area in the control barn (p < 0.05). There were no differences in the length of the recorded behaviors between the treatments. These findings suggest that, in general, the elevated perforated floor is attractive for the animals. However, it does not promote one of the recorded behavior patterns. Our results show that an elevated perforated floor could be an option for structuring broiler barns.

Effects of a Partially Perforated Flooring System on Ammonia Emissions in Broiler Housing-Conflict of Objectives between Animal Welfare and Environment?

A partially (50%) perforated flooring system showed positive effects on health- and behavior-based welfare indicators without affecting production performance. Ammonia (NH3) is the most common air pollutant in poultry production, with effects on animal welfare and the environment. The objectives of animal welfare and environmental protection are often incompatible. Therefore, this study addresses the question of how a partially perforated flooring system affects NH3 emissions. According to German regulations, three fattening periods were carried out with 500 Ross 308 broilers per barn (final stocking density: 39 kg m-2). The experimental barn was equipped with an elevated perforated area in the supply section, accessible by perforated ramps. The remaining area in the experimental barn and the control barn were equipped with wood shavings (600 g m-2). Besides the different floor types, management was identical. Air temperature (Temp), relative air humidity (RH), NH3 concentration, and ventilation rate (VR) were measured continuously. Furthermore, dry matter (DM) content, pH, and litter quality were assessed. Towards the end of the fattening periods, the NH3 emission rate (ER) of the partially perforated flooring system was higher compared with that of the littered control barn (all p < 0.001). This effect is mainly caused by the higher NH3 concentrations, which are promoted by the lack of compaction underneath the elevated perforated area and the increase in pH value under aerobic conditions. Nevertheless, the partially perforated flooring system offers different approaches for NH3 reduction that were previously not feasible, potentially contributing equally to animal welfare and environmental protection.

Effects of a slatted floor on bacteria and physical parameters in litter in broiler houses.

In this study, a new housing system for broiler was tested. This system consisted of a slatted floor area and a littered area with the aim of improving litter quality. Two experimental broiler houses were provided. In house 1, a slatted floor was installed below the drinker and feedlines. Littered areas flanked the slatted floor. Broiler house 2 reflected conditions in commercial systems, consisting of a full littered area. Litter samples were taken at day 11 and at day 32 of the fattening period. Manure samples were taken at day 32. The total bacteria count (TBC), coliforms, Escherichia coli (E. coli) and ESBL-producing bacteria were determined. Furthermore, physical parameters (dry matter, water activity, pH) of litter and manure were measured. For statistical analyzes, a generalized linear mixed model (GLIMMIX procedure) was calculated. The floor did not show any significant effect on the bacteria content of the litter. Regarding TBC in litter, the floor showed a tendency for an effect (F = 5.42, p<0.1) with lower contents in house 1. Regarding the manure under the slatted floor, a tendency for a difference between house 1 and house 2 was found for the content of E. coli (F = 5.55, p<0.1) with higher contents in house 1. The floor did not show any significant effect on the physical parameters of litter and manure. The results of this experimental study showed no positive effects on the selected litter parameters, but further studies, especially on-farm experiments are necessary to confirm these results.

First approach validating a scoring system for foot-pad dermatitis in broiler chickens developed for application in practice.

Measuring the severity of foot-pad dermatitis is an accepted tool monitoring the quality of animal husbandry and welfare. Up to now, a variety of scoring schemes have been used, most of them based on visual evaluation. However, a standardisation and validation of scoring systems is beneficial, not only to compare different studies, but to provide objective indicators in poultry welfare. In this study, we validated one visual scoring system, widely used in Northern Germany, by using additional information of histological measurements. Therefore, feet of broiler chickens (ROSS 308) from one flock were visually scored at the slaughter plant (4-point score). Ten feet per score level (n = 40) were sampled and analysed macroscopically and microscopically. Data were analysed using cluster analysis, providing a classification based on these histopathological findings. Validity of the visual scoring system was analysed by (1) testing the interobserver reliability between different observers and (2) by comparing both, visual and cluster classification types using the McNemar's test. In a last step Kendall tau correlations were calculated in order to find suitable parameters to judge the severity in a visual score more reliably. Results could show that most agreement was found for the score levels 1 and 2, whereas results for score levels 3 and 4 were more divergent. These results were found in both, interobserver reliability and comparison of classification types (visual vs. cluster). Results revealed interaction effects of classification type and scoring level for the width of ulcers (p = 0.0044) and the size of the lesion (p = 0.0081). In the cluster classification, higher values in both, width of ulcer and size of lesion could be found in score level 3. Furthermore, a positive correlation of the size of lesion with the depth of the ulcer was found (0.73). In conclusion, we found that histological findings coincided well with the less severe visual scores (1; 2), whereas the differentiation between the severe scores (3; 4) seemed to be less valid. For practical purposes we therefore recommend keeping visual scoring systems simple. Furthermore, as the correlation coefficient between both was quite high, the size of the lesion might serve as an indirect indicator of the depth.