Characterization, mode of action, and efficacy of twelve silica-based acaricides against poultry red mite (Dermanyssus gallinae) in vitro.

Poultry red mite infestation still is an unsolved problem in poultry farms. Legal regulations, residue risks, and resistances limit chemical control of mites. Alternatives to chemical acaricides for control of poultry red mite are silica-based products, which have as a main constituent silicon dioxide. The acaricidal effect is attributed to sorptive properties of the particles, which result in the mite's death by desiccation. In the present study, the acaricidal efficacy of 12 products containing natural or synthetic silica, 9 in powder form, and 3 for liquid application was tested under laboratory conditions. Mite mortality was measured at several intervals and the mean lethal time (LT50) determined by Probit analysis after Abbott's correction. The LT50 values of the products significantly differed (Tukey's HSD p < 0.05). LT50 values of powdery formulations ranged from 5.1 to 18.7 h and overlapped with those of the fluid ones which ranged from 5.5 to 12.7 h. In order to explain the differences in efficacy of the tested silica products, further characterizations were carried out. X-ray fluorescence, specific surface, cation exchange capacity (CEC), and water absorption capacity (WAC) were measured. Furthermore, electron microscopy was conducted and different products compared. Silicon dioxide content (ranging from 65 to 89% for powders and 57 to 80% for fluids) had no significant impact on efficacy, while specific surface and CEC (2.4-23.2 mEq 100(-1) g(-1) for powders and 18-30.8 mEq 100(-1) g(-1)) were positively and WAC (1.3-4.4 wt% for powders and 3.3-4.8 wt% for fluids) negatively related to the acaricidal efficacy. Influence of these parameters on acaricidal efficacy was significant according to the results of a stepwise regression analysis (p < 0.01).

The Relationships between Damaging Behaviours and Health in Laying Hens.

Since the ban in January 2012 of conventional cages for egg production in the European Union (Council Directive 1999/74/EC), alternative systems such as floor, aviary, free-range, and organic systems have become increasingly common, reaching 50% of housing for hens in 2019. Despite the many advantages associated with non-cage systems, the shift to a housing system where laying hens are kept in larger groups and more complex environments has given rise to new challenges related to management, health, and welfare. This review examines the close relationships between damaging behaviours and health in modern husbandry systems for laying hens. These new housing conditions increase social interactions between animals. In cases of suboptimal rearing and/or housing and management conditions, damaging behaviour or infectious diseases are likely to spread to the whole flock. Additionally, health issues, and therefore stimulation of the immune system, may lead to the development of damaging behaviours, which in turn may result in impaired body conditions, leading to health and welfare issues. This raises the need to monitor both behaviour and health of laying hens in order to intervene as quickly as possible to preserve both the welfare and health of the animals.

Effects of Elevated Grids on Growing Male Chickens Differing in Growth Performance.

Pullets, i. e., chickens of layer lines are often raised in housings equipped with perches. In contrast, broiler chickens most often are raised in a barren environment that lacks any three-dimensional structures, even though broilers also are motivated to use elevated structures. In addition, environmental enrichment may improve welfare problems in broiler chickens, such as skeletal disorders or contact dermatitis. Due to ethical reasons, currently there are attempts to fatten the male chickens of layer strains or to use dual purpose strains. However, there is only limited knowledge on the behavior of these chickens until now. The aim of this study was to test the use of elevated grids and their effect on animal-based indicators (e.g., physical condition). In two successive trials, we kept a total of 1,217 male chickens from three strains (Lohmann Dual, Lohmann Brown Plus, Ross 308) that show differences in growth performance in 24 pens (two trials × three strains × eight pens). In half of the pens, grids were offered at three different heights (enriched groups); in the other half of the pens, no elevated structures were installed (control groups). We recorded the number of birds using the grids at the different heights as well as locomotor activity, walking ability, plumage cleanliness, and the footpad health of chickens. Chickens with low and medium growth performance preferred the highest grids during both the light and dark periods. In contrast, fast-growing chickens used the lowest grid more frequently. Fast-growing chickens kept in the enriched pens tended to have a higher level of locomotor activity and reduced chest cleanliness. Chickens from the medium growth performance strain showed better walking ability when kept in the enriched pens. Enrichment did not affect any of the welfare measures in the slow-growing chickens. These findings suggest that elevated structures may improve chicken welfare, particularly for medium growing chickens. For fast-growing chickens we found evidence for an improvement of animal-based indicators although they used the elevated structures less. However, regardless of growth performance, elevated grids offer the birds an opportunity to rest in a species-specific manner.

[Influence of litter moisture around drinkers and feeders on foot pad health status of fattening turkeys during the early rearing period]. / Einfluss der Einstreufeuchte im Futter- und Tränkebereich auf die Fussballengesundheit von Mastputen in der Aufzuchtphase.

The present study demonstrates the influence of increased litter moisture (LM) around drinkers and feeders on the foot pad health status of fattening turkeys during the rearing period. Therefore 154 day-old British United Turkeys (B.U.T.) 6 turkey poults (77 males, 77 females) were kept on softwood shavings with different moisture contents for a time period of 29 days. Separated by gender the poults were randomly allotted to two test groups and one control group. Birds in test groups were kept on defined litter moisture contents of 30% or 50% around drinkers and feeders. Additionally, birds of each group had access to an area which was maintained as dry as possible (LM around 10%). Birds in control groups were completely kept on dry litter (LM 10 %). Foot pads of all birds were examined according to the external scoring system of Mayne et al. (2007a). Cross-sex comparisons showed a significant difference of prevalence and severity of foot pad dermatitis between turkeys of the test groups and those of the control groups. At the end of this experiment female turkeys had no higher severity of foot pad dermatitis than male turkeys.Thus, the present results indicate that already areas of wet litter within a dry stable may lead to an increase of the prevalence and severity of foot pad dermatitis during the early rearing period.

[Examination of the prevalence of skin injuries in debeaked fattened turkeys]. / Untersuchungen zur Prävalenz von Hautverletzungen bei schnabelkupierten Mastputen.

Within the framework of a cooperative research project, turkey health as well as numerous aspects of animal welfare were examined in various intensive commercial farms with varying rearing forms. The present study demonstrates the prevalence of skin injuries concerning living animals as well as carcasses of slaughtered turkeys of both sexes. Although all turkeys were debeaked, prevalences of skin injuries at a value of 12.8% with male turkeys and 13.8% with female turkeys could be found at the age of 16 weeks. Within the scope of medically inspections skin injuries were mainly established in the head region, especially the snood as well as in the region of the back. By means of their clinical picture pecking wounds and scratch injuries could be distinguished. Skin lesion produced primary as a result of scratching the skin surface, could be enlarged by the animal itself or by conspecifics by beak pecking, especially after bleeding, in spite of debeaked upper beak. Injuries in the head region, especially of the snood, could be explained mainly as a result of pecking by conspecifics by reason of their clinical picture and were found mainly in male turkeys. Skin injuries in the region of the back, especially at the coxal tuberosity, were identified primarily as scratch marks. They were found mainly in female turkeys. A statistically significant correlation of the injury prevalence to particular husbandry parameters discussed in the literature as "predisposing" or "limiting" factors (e.g., population density, light regime or offer of employment material) could not be established in this study. At the meat inspection fresh scratching injuries at the chest and the hind legs were diagnosed most often. Especially fresh injuries of the carcass point to a misguided behaviour of the staff concerning animal handling during loading and transport which is not conform to animal welfare.

[Effect of litter type on prevalence and severity of pododermatitis in male broilers]. / Einfluss der Einstreuart auf Prävalenz und Schweregrad von Pododermatitis bei männlichen Broilern.

During the course of two trial periods on broilers (Ross 308), the effects of 5 different types of litter (chopped straw, wood shavings, spelt glumes, Pelletinos, HygieneWood-Shavings) on the development of pododermatitis and animal performance (body weight, feed conversion, mortality) were investigated. Pelletinos are for sale under the name Pelletino Strohstreugranulat G. HygieneWood-Shavings are a special product that currently is not available on the market. Male broilers were kept under practical conditions (feeding, light program) for 35 days. Foot pad lesions could already be observed at the first assessment on their 7th day after hatching. Broilers kept on chopped straw showed in both trials the highest score (trial 1: 1.50; trial 2: 1.58). Animals reared on Pelletinos (trial 1: 0.59; trial 2: 0.17) followed by HygieneWood-Shavings (trial 1: 0.63; trial 2: 0.47), wood shavings (trial 1: 1.30; trial 2: 0.71) and spelt glumes (trial 1: 1.13, trial 2:0.93) showed significant lower lesions. During the second trial, the average body weights were significantly higher while feed conversion was lower.The mortality on the other hand showed no significant differences between the trials. Groups kept on Pelletinos showed the best foot pads and the highest body weights in both trials at the end of experiments. The investigation showed that the prevalence and the severity of pododermatitis as well as the performance could be influenced by various types of litter. Chopped straw which is standard for the broiler industry in Germany, seems to be the least suitable variant in our study.

[Examination of rearing standards and health status in turkeys in Germany]. / Erhebungen zur Haltung und Gesundheit bei Mastputen in Deutschland.

Within the framework of a cooperative research project, sponsored by the Federal Ministry of Food, Agriculture and Consumer Protection in Germany (BMELV), turkey health as well as numerous aspects of animal welfare in various intensive commercial farms with varying rearing forms were examined. For this purpose extensive documentation of flock management and health status information was conducted over the past two years at the farms. Additional information was ascertained from the carcasses at the slaughterhouse. The first results of this study, which look at flock management, will be presented here. Upon reviewing the questionnaires, it is clear that on one hand almost all farmers orientate there stocking rate upon the allowed limits, on the other hand, however, when considering national general requirements, which are very important parameters thatargely influence animal health (i. e. litter quality and care of sick/injured animals) farmer compliance lacks. Especially the litter quality, which, among other parameters, plays a very important role in food pad health, proved to be unsatisfactory. Unfortunately, no instruments are available that measure the litter quality, yet. The status of footpad health was a major problem in all the rearing systems. However, the prevalence of epithelial necrosis and deep skin lesions varied immensely among different flocks of the same age.