Alternatives to formulate laying hen diets beyond the traditional least-cost model

Owing to the high cost of feed for poultry, there is continuous pressure to formulate 'least-cost' diets that meet nutritional requirements. However, the main aim of any commercial enterprise is usually to maximize profits with the resources or inputs available, and the conventional or historic tool of least-cost ration formulation has limitations in a more demanding economic environment. The layer industry may experience particularly volatile changes in egg price, principally owing to changes in supply rather than demand, and in the past, it has been reported to possess less production and financial data reporting than other industries. Thus, increased flexibility during these uncertain times may give the layer industry greater opportunity and capacity to cope with market fluctuations. A practical example of how a laying hen operation may benefit from these approaches demonstrates that the maximum-profit solution does not always match the least-cost solution and that stochastic feed formulation may be used to accurately assign safety margins and define the level of certainty this safety margin will provide. Finally, as producers better understand how their hens respond to different dietary specifications, the opportunity arises to choose the set of specifications that result in maximum profits for their unique situations, rather than relying on least-cost diets formulated to nutrient requirements alone

Raw material nutrient variability has substantial impact on the potential profitability of chicken meat production

Feed accounts for more than 65% of live production costs of poultry production; thus, accurate feed formulation is vital to ensure poultry are receiving an optimal diet and nutrients are not in undersupply or oversupply. However, this is difficult when the nutrient compositions of feed ingredient batches are highly variable. To help reduce the variability in the specified finished feeds, appropriate sampling methodology is critical. Nevertheless, recommended methodology and depth of detail within technical articles varies greatly and does not always reflect the recommendations of the Association of Official Analytical Chemists, a nonprofit scientific association that publishes standardized analytical methods. It is often understood that increased variability in ingredients due to poor sampling technique is detrimental to industry, but the potential economic cost of poor sampling is often not appreciated. Thus, the extent that variation in protein in feed ingredients affects expected performance and profits for the poultry industry was modeled. It was demonstrated that it is possible to incur a 63% reduction in gross margin or a difference of up to $19,053 (USD) in gross margin from one cycle of 30,000 broilers by simply overestimating the nutrient content of feedstuffs. Assuming a poultry company may produce approximately 1,000 broiler cycles per year, this equates to a loss of up to$19 million (USD). Hence, it is clear that identifying the most accurate way to sample, and improving the understanding and implementation of proper sampling methodology, should be a priority

Individual determinants of social fairness assessments : the case of Germany

In this contribution we study the determinants of how individuals assess the social fairness of a given income distribution. We propose an analytical framework distinguishing between potential impact factors related to the following fields: first fairness preferences, second beliefs on the sources of economic success and the functioning of democracy and third selfinterest. We test this framework on representative survey data for Germany for the years 1991, 2000 and 2004. Our results indicate that self-interest, beliefs and fairness preferences jointly shape fairness assessments. In addition, a number of personal characteristics are found to be important: Compared to their western fellow citizens, people born in GDR have a more critical view at social fairness. A particularly strong impact is related to the belief on the functioning of the democratic system. This points an important role of procedural fairness for the acceptance of a given distribution

Don't tax me? : Determinants of individual attitudes toward progressive taxation

This contribution empirically analyses the individual determinants of tax rate preferences. For that purpose we make use of the representative German General Social Survey (ALLBUS) that offers data on the individual attitudes toward progressive, proportional, and regressive taxation. Our theoretical considerations suggest that beyond self-interest, information, fairness considerations, economic beliefs and several other individual factors drive individual preferences for tax rate structures. Our empirical results indicate that the self-interest view does not offer the sole explanation for the heterogeneity in attitudes toward progressive taxation. Rather, we show that the choice of the favoured tax rate is also driven by fairness considerations

The early bee catches the flower - circadian rhythmicity influences learning performance in honey bees, Apis mellifera

Circadian rhythmicity plays an important role for many aspects of honey bees’ lives. However, the question whether it also affects learning and memory remained unanswered. To address this question, we studied the effect of circadian timing on olfactory learning and memory in honey bees Apis mellifera using the olfactory conditioning of the proboscis extension reflex paradigm. Bees were differentially conditioned to odours and tested for their odour learning at four different “Zeitgeber” time points. We show that learning behaviour is influenced by circadian timing. Honey bees perform best in the morning compared to the other times of day. Additionally, we found influences of the light condition bees were trained at on the olfactory learning. This circadian-mediated learning is independent from feeding times bees were entrained to, indicating an inherited and not acquired mechanism. We hypothesise that a co-evolutionary mechanism between the honey bee as a pollinator and plants might be the driving force for the evolution of the time-dependent learning abilities of bees

Teaching the principles of least-cost poultry feed formulation utilizing the Solver function within a computer software workbook

A Microsoft Excel workbook, User-Friendly Feed Formulation with Data from Australia (UffdAu.xlsm), has been developed for teaching feed formulation techniques to tertiary level, university students. It runs under both Microsoft Windows and Apple iOS operating systems. The example ingredient composition matrix is based on the Australian Feed Ingredient Database to illustrate the biological and econometric principles of least-cost feed formulation. The nutrient data are based roughly on recent primary breeder company recommendations. The workbook is easily adapted to appropriate ingredients, nutrients, and prices most relevant to the students, wherever it is used. The workbook uses the linear routines of Excel's Solver add-in under the Data heading in the header Ribbon. There is a worksheet illustrating how to adapt non-linear responses such as exogenous enzymes to typical linear models using a step function. Additional worksheets illustrate how proximate analysis can be interpreted in modern analytical chemistry terms and, how various feed energy measures are related to feed composition