Browsing by Subject "Tierhaltung"

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Beurteilung von Geruchsimmissionen aus der Tierhaltung
(2011) Gallmann, Eva; Jungbluth, Thomas
Odours from farm animal production can cause significant problems. It is therefore appropriate to develop suitable procedures for their assessment and limitation in the sense of immission control. The challenge comprises the objectification of the odours, bearing in mind that their effect is very individual, subjective and emotion-based. The resultant work offers a contribution towards the classification and further development of procedures for assessment of odours from farm animal production. The latest knowledge of the various aspects of measurement and evaluation of farm animal production odour immissions will be analysed in detail through ongoing literature assessment and from results of own investigations. The perceived nuisance effect relies on multiple stimulus-based variables associated with context and person. Measuring the associated effect can take place through psychometric surveys. Assessment of a significant nuisance effect within a group is conventionally based on the proportion of subjected persons that can be regarded as tolerable. Odours from farm animal production in particular are considered on the basis of investigations and data concerning odour components and their emission, transmission and immission. The extent of available data including results from own odour emission measurements give a high degree of scatter. This scatter is caused by the multiplicity of influences on emissions and also through the imprecision of measurements based on olfactometry. There are limitations on the extent to which reduction measures can be quantified. Dispersion modelling is an important tool for assessing odour immissions, but is also associated with limitations as shown by validation and sensitivity investigations. Particularly decisive are the appropriate illustration of the transmission and the choice and modification of the model structure and input parameters. The modelling of diffuse and varying sources near the ground surface remains a challenge. The consideration of cold air outflows is essential for immission assessment. The common odour threshold distances from pig and cattle production units determined via odour plume measurements are discussed using numerous trial results as examples. The results of own grid measurements at four locations are detailed, also with regard to the effect of a plausibility control, the variation of the odour hour criterion, and compared with dispersion calculations. Grid measurements help in the differentiated measurement of the immission situation. In the interpretation of absolute values, the imprecision area around the real value must be considered. The effect of immission reduction measures is hardly quantifiable nor able to be generalised. The knowledge is based, above all, on flow simulations and on experience. Main points of influence are the dilution of outflow air, the transmission conditions and the location circumstances. The immission hedonics from farm animal production odours were compared and recorded for own investigations and within the framework of a cooperative project “Odour assessment in agriculture“. The hedonic differences were not, however, nuisance-relevant as shown by evaluation of the exposition effect relationships within the same trial framework. The differences regarding type of farm animal are, however, relevant. The results from various epidemiological studies were thoroughly analysed because these were oriented on the assessment procedure for immissions and their effects. The starting point for assessing odour emissions from farm animal production can differ more through source-oriented distance rules or immission regulations for the limitation of odour hour frequency or odour concentration. Both points provide possibilities for recognition of animal type differences via factor weighting of animal mass, animal numbers or key immission figures. The assessment principle for distance standards that apply to all types of farm animals with factor weighting for source, transmission and immission parameters, or as empirical distance model, are explained and assessed based on examples from Switzerland, Austria and Germany. The methods and the establishment of factors are less well able to be appreciated as the degree of differentiation increases. The determinations within the odour immission guideline are compared with the regulations for odour exposition limits in the Netherlands, and in other countries. The suitability of the assessment bases and procedures for assessment are finally evaluated for assessment in practical conditions and recommendations for further developments suggested.
Functions and selection criteria for a llama population in the Bolivian Andes
(2010) Markemann, André; Valle Zárate, Anne
Bolivia accounts for more than 60% of the llama population worldwide and more than 50,000 smallholder families in marginal areas are dedicated to llama husbandry as part of their livelihood strategy. To this day, llamas substantially contribute to the economic and social life of smallholder Andean communities, providing food and fibre, fuel and transport, and fulfil other cultural, social and capital functions. Although this multi-purpose contribution has been widely recognised, llamas have not yet been subject to systematic breeding activities in the Andean region. For the establishment of sound and sustainable breeding programmes, it is crucial to identify the contribution of the numerous non-market traits and functions of llamas to the breeding objective. The present study was conducted within a long-term collaboration project in the Ayopaya region and aimed at evaluating the important functions, roles and traditional selection criteria of llamas, intending to contribute to formerly missing information for the formalisation of an appropriate breeding objective. Data was collected in seven highland communities of the north-western Ayopaya province in the Cochabamba department, Bolivia. Semi-structured interviews were conducted in 47 households in three communities. Questionnaires contained information on llama herd structure and management, animal selection and selection criteria. In addition, information from llama registers and previous research results were included for comparison and crosschecking. Verbatim noted selection criteria were evaluated by a relative weighting on an ordinal scale. A ranking approach with ten functions of llama keeping presented by illustrations was performed with 75 farmers in six communities. A rank-based t-test was applied for multiple pair-wise comparisons within ranking groups according to gender and community provenance. Between-group comparison was performed by non-parametric Wilcoxon rank-sum test. A choice experiment (CE) was designed on basis of the results of the evaluation of stated selection criteria for llama breeding males. In total, five attributes and a payment vehicle were included in the CE. A total of 32 different llama profiles were selected from the full factorial design. The profiles were further blocked into pairs of two, resulting in eight choice sets with two alternatives and an opt-out alternative, which were presented to 159 farmers in seven communities. Data analysis was performed using LIMDEP 8.0 NLOGIT 3.0 applying a mixed logit model (MXL). According to farmers? rankings, the major functions of llama keeping in the Ayopaya region are herd size as a capital asset and transportation, the latter highlighting the role and value of livestock in a mixed system and their integration into cropping activities, but also the persisting value of animal transport in marginal regions despite infrastructure development and decline of barter trade. The high importance of the transport capability of llamas is reflected in the body conformation as a frequently stated selection criterion. Other precisely defined and highly valued criteria were well-developed testicles, fibre quantity and quality and fleece colour. The high-rated testicle conformation in combination with little or no selection on the female side is promoting the maintenance of a sufficient herd size, which is indirectly assuring a convenient capital investment. Maximum likelihood estimates of the MXL showed the expected signs for all attributes. Highest simulated WTP values were observed for very fine fibre animals. Further, a llama with a single-coloured fleece is valued more than a spotted one and bigger animals are preferred over smaller ones. The body and testicle conformation traits receive a negative value, typically denominated willingness to accept (WTA) compensation. Highest aversion of farmers is expressed towards animals with unequal testicles, followed by small testicles and crooked legs. However, the 25th and 75th percentiles of the WTP estimates point to considerable preference variation within the respondent population that could not be sufficiently captured by the included demographic characteristics in the MXL model. The presented mixed-methodological approach was able to partly describe the complexity and multi-functionality of llamas in marginal highland farming systems in Bolivia. The different approaches allowed yielding more insights in the relative importance of the functions the animals fulfil for their herders and the predominant selection criteria considered for breeding animals. The special importance of marketable and non-marketable benefits of llamas in Bolivia due to smallholder?s multiple objectives has been quantified in monetary terms. With regard to the formalisation of a breeding objective for llamas in the Bolivian highlands, the findings suggest the incorporation of the traditionally important selection criteria of farmers in parallel to the commercially interesting fibre trait. As long as no proper price information from functioning national fibre markets is available, an economic weighting of the fibre quality trait on basis of WTP estimates appears a reasonable alternative. There is need for additional work and research on the genetic correlations, apart from the existent phenotypic calculations, between fibre quality and quantity to identify possible auxiliary traits to facilitate recording and implementation. The derivation of economic weights for traits from choice experiments to be incorporated in animal breeding selection indices remains a challenge. In parallel, the market development for llama products should be sequentially monitored, while shortcomings and constraints on the producer level, the institutional level and the policy level have to be considered.
Zweinutzungshuhn – wie schmeckt das? Sensorische Beurteilung von Hühnerfleisch und Eiern von vier Zweinutzungshuhn-Genetiken
(2023) Gebhardt, Beate; Maute, Jutta; Kiefer, Lukas
Research into the sensory properties of meat and eggs from dual-purpose chickens has so far been a niche from a scientific point of view. In cooperation with the EIP-Agri project "ZweiWert", students at the DHBW Heilbronn therefore tasted, analysed and evaluated several dual-purpose chicken genetics in the integration seminar "Dual-purpose chickens: How to communicate the added value" in summer 2023. The genetics “Coffee" from the Ökologische Tierzucht (ÖTZ), "Sundheimer" from the Öko2Huhn project, "RegioHuhn" and "Lohmann Dual" as well as a control group from a classic laying or fattening line were assessed. The aim was to find out how different dual-purpose chickens taste and whether there are sensory differences or special features in meat and eggs Sensory attributes, including appearance, taste and smell, were recorded using a multi-methods assessment sheet. In short, the results of this explorative study show that dual-purpose chickens taste better. However, according to the testers judgement, there are differences not only between the different genetics, but also between the individual parts - breast, drumstick, wings or broth. The sensory profiles of the four dual-purpose chickens tested are varied and do not allow a clear sensory "ranking". The meat from Lohmann Dual apparently corresponds best to consumer preferences, while their eggs (cooked) are the least appealing. Overall, however, there is a consistent sensory superiority of the dual-purpose chickens over the specialised fattening or laying breed. These results - should they be confirmed in further studies - could contribute to increasing consumer acceptance of dual-purpose chickens and addressed in market communication to their further spread. The EIP project titled "Building Value Chains for Dual-Purpose Chickens in Baden-Württemberg" (ZweiWert) is funded by the Ministry of Food, Rural Areas and Consumer Protection of Baden-Württemberg from 01/2022 to 12/2024. Project partners include the Naturland Association of Baden-Württemberg, several departments of the University of Hohenheim, and many partners from agricultural production and marketing.