Effects of housing, perches, genetics, and 25-hydroxycholecalciferol on keel bone deformities in laying hens

Several studies have shown a high prevalence of keel bone deformities in commercial laying hens. The aim of this project was to assess the effects of perch material, a vitamin D feed additive (25-hydroxyvitamin D3; HyD, DSM Nutritional Products, Basel, Switzerland), and genetics on keel bone pathology. The study consisted of 2 experiments. In the first experiment, 4,000 Lohmann Selected Leghorn hens were raised in aviary systems until 18 wk of age. Two factors were investigated: perch material (plastic or rubber-coated metal) and feed (with and without HyD). Afterward, the hens were moved to a layer house with 8 pens with 2 aviary systems. Daily feed consumption, egg production, mortality, and feather condition were evaluated. Every 6 wk, the keel bones of 10 randomly selected birds per pen were palpated and scored. In the second experiment, 2,000 Lohmann Brown (LB) hens and 2,000 Lohmann Brown parent stock (LBPS) hens were raised in a manner identical to the first experiment. During the laying period, the hens were kept in 24 identical floor pens but equipped with different perch material (plastic or rubber-coated metal). The same variables were investigated as in the first experiment. No keel bone deformities were found during the rearing period in either experiment. During the laying period, deformities gradually appeared and reached a prevalence of 35% in the first experiment and 43.8% in the second experiment at the age of 65 and 62 wk, respectively. In the first experiment, neither HyD nor the aviary system had any significant effect on the prevalence of keel bone deformities. In the second experiment, LBPS had significantly fewer moderate and severe deformities than LB, and rubber-coated metal perches were associated with a higher prevalence of keel bone deformities compared with plastic perches. The LBPS laid more but smaller eggs than the LB. Again, HyD did not affect the prevalence of keel bone deformities. However, the significant effect of breed affiliation strongly indicates a sizeable genetic component that may provide a basis for targeted selectio

Tourism and water inequity in Bali: A social-ecological systems analysis

This paper is a social-ecological systems (SES) analysis of tourism and water inequity in Bali. It uses Elinor Ostrom’s SES model to look at the particular niche of Bali’s tourism and water nexus. Re-analysis of previous qualitative research revealed that the vulnerability of the SES was due to numerous characteristics. In particular, user groups are highly diverse, transient and stratified, thereby inhibiting communication and knowledge sharing. This, in combination with weak governance systems and the economic power of the tourism industry, interact to affect declining water resources and the iniquitous impact of this. Whilst there are obvious indications that Bali’s water resources are over stretched, there is no feedback loop to the institutional structures that would help enable appropriate responses from the user groups or governance system

Winter habitat selection and conservation of Hazel Grouse(Bonasa bonasia) in mountain forests

The Hazel Grouse (Bonasa bonasia) has suffered from habitat loss due to changes in forestry practices in many regions of Europe. The widespread conversion of structurally heterogeneous to uniform, single-layered stands has caused many of its populations to decline. The trend in multi-functional forestry towards more dynamic processes and natural rejuvenation offers a unique opportunity to restore many habitats of Hazel Grouse in core areas of its actual distribution. As the Alps represent a stronghold of Hazel Grouse distribution in Central Europe, we aimed to determine the species–habitat relationship in mountain forests. We assessed the distribution and characteristics of Hazel Grouse habitat in a forest reserve of the Swiss Alps. Abiotic, structural and vegetation characteristics were investigated at the small scale, and abiotic and forest inventory data at the large scale. We compared the habitat characteristics of used and unused forest stands with a raster system consisting of bird presence and absence cells by applying a logistic regression. Hazel Grouse preferred stands with high proportions of tall rowans, forest edges, and a dense shrub layer at the small scale. Rowans had the strongest influence on Hazel Grouse occurrence. At the large scale, Hazel Grouse preferred forests with large proportions of alder and a diverse mosaic of canopy closure and stand structure. For 44% of the study area, the large-scale model predicted a probability of Hazel Grouse occurrence of more than 0.5. Our data supports the recommendation that the availability of suitable habitat for Hazel Grouse can be increased by natural reforestation of tree-fall gaps and stands with bark beetle infestation, as well as by enhancing the proportion of old-growth stands. Both measures will augment the shrub cover and number of rowan trees, two essential habitat and food resources for Hazel Grouse in mountain forests