A dynamic programming model for optimising feeding and slaughter decisions regarding fattening pigs

Costs of purchasing new piglets and of feeding them until slaughter are the main variable expenditures in pig fattening. They both depend on slaughter intensity, the nature of feeding patterns and the technological constraints of pig fattening, such as genotype. Therefore, it is of interest to examine the effect of production technology and changes in input and output prices on feeding and slaughter decisions. This study examines the problem by using a dynamic programming model that links genetic characteristics of a pig to feeding decisions and the timing of slaughter and takes into account how these jointly affect the quality-adjusted value of a carcass. The model simulates the growth mechanism of a pig under optional feeding and slaughter patterns and then solves the optimal feeding and slaughter decisions recursively. The state of nature and the genotype of a pig are known in the analysis. The main contribution of this study is the dynamic approach that explicitly takes into account carcass quality while simultaneously optimising feeding and slaughter decisions. The method maximises the internal rate of return to the capacity unit. Hence, the results can have vital impact on competitiveness of pig production, which is known to be quite capital-intensive. The results suggest that producer can significantly benefit from improvements in the pig's genotype, because they improve efficiency of pig production. The annual benefits from obtaining pigs of improved genotype can be more than €20 per capacity unit. The annual net benefits of animal breeding to pig farms can also be considerable. Animals of improved genotype can reach optimal slaughter maturity quicker and produce leaner meat than animals of poor genotype. In order to fully utilise the benefits of animal breeding, the producer must adjust feeding and slaughter patterns on the basis of genotype. The results suggest that the producer can benefit from flexible feeding technology. The flexible feeding technology segregates pigs into groups according to their weight, carcass leanness, genotype and sex and thereafter optimises feeding and slaughter decisions separately for these groups. Typically, such a technology provides incentives to feed piglets with protein-rich feed such that the genetic potential to produce leaner meat is fully utilised. When the pig approaches slaughter maturity, the share of protein-rich feed in the diet gradually decreases and the amount of energy-rich feed increases. Generally, the optimal slaughter weight is within the weight range that pays the highest price per kilogram of pig meat. The optimal feeding pattern and the optimal timing of slaughter depend on price ratios. Particularly, an increase in the price of pig meat provides incentives to increase the growth rates up to the pig's biological maximum by increasing the amount of energy in the feed. Price changes and changes in slaughter premium can also have large income effects. Key words: barley, carcass composition, dynamic programming, feeding, genotypes, lean, pig fattening, precision agriculture, productivity, slaughter weight, soybeans

High global diversity of cycloviruses amongst dragonflies

Members of the family Circoviridae, specifically the genus Circovirus, were thought to infect only vertebrates; however, members of a sister group under the same family, the proposed genusCyclovirus, have been detected recently in insects. In an effort to explore the diversity of cycloviruses and better understand the evolution of these novel ssDNA viruses, here we present five cycloviruses isolated from three dragonfly species (Orthetrum sabina, Xanthocnemis zealandica and Rhionaeschna multicolor) collected in Australia, New Zealand and the USA, respectively. The genomes of these five viruses share similar genome structure to other cycloviruses, with a circular ~1.7 kb genome and two major bidirectionally transcribed ORFs. The genomic sequence data gathered during this study were combined with all cyclovirus genomes available in public databases to identify conserved motifs and regulatory elements in the intergenic regions, as well as determine diversity and recombinant regions within their genomes. The genomes reported here represent four different cyclovirus species, three of which are novel. Our results confirm that cycloviruses circulate widely in winged-insect populations; in eight different cyclovirus species identified in dragonflies to date, some of these exhibit a broad geographical distribution. Recombination analysis revealed both intra-and inter-species recombination events amongst cycloviruses, including genomes recovered from disparate sources (e.g. goat meat and human faeces). Similar to other well-characterized circular ssDNA viruses, recombination may play an important role in cyclovirus evolution. © 2013 SGM.

The success of the diversified farm : resource-based view

Farms and rural areas have many specific valuable resources that can be used to create non-agricultural products and services. Most of the research regarding on-farm diversification has hitherto concentrated on business start-up or farm survival strategies. Resource allocation and also financial success have not been the primary focus of investigations as yet. In this study these specific topics were investigated i.e. resource allocation and also the financial success of diversified farms from a farm management perspective. The key question addressed in this dissertation, is how tangible and intangible resources of the diversified farm affect the financial success. This study’s theoretical background deals with resource-based theory, and also certain themes of the theory of learning organisation and other decision-making theories. Two datasets were utilised in this study. First, data were collected by postal survey in 2001 (n = 663). Second, data were collected in a follow-up survey in 2006 (n = 439). Data were analysed using multivariate data analyses and path analyses. The study results reveal that, diversified farms performed differently. Success and resources were linked. Professional and management skills affected other resources, and hence directly or indirectly influenced success per se. In the light of empirical analyses of this study, tangible and intangible resources owned by the diversified farm impacted on its financial success. The findings of this study underline the importance of skills and networks for entrepreneur(s). Practically speaking all respondents of this study used either agricultural resources for non-farm businesses or non-farm resources for agricultural enterprises. To share resources in this way was seen as a pragmatic opportunity recognised by farmers. One of the downsides of diversification might be the phenomenon of over-diversification, which can be defined as the situation in which a farm diversifies beyond its optimal limit. The empirical findings of this study reveal that capital and labour resource constrains did have adverse effects on financial success. The evidence indicates that farms that were capital and labour resource constrained in 2001 were still less profitable than their ‘no problems’ counterparts five years later.

Determinants of farmer retirement and farm succession in Finland

In the past decade, the Finnish agricultural sector has undergone rapid structural changes. The number of farms has decreased and the average farm size has increased when the number of farms transferred to new entrants has decreased. Part of the structural change in agriculture is manifested in early retirement programmes. In studying farmers exit behaviour in different countries, institutional differences, incentive programmes and constraints are found to matter. In Finland, farmers early retirement programmes were first introduced in 1974 and, during the last ten years, they have been carried out within the European Union framework for these programmes. The early retirement benefits are farmer specific and de-pend on the level of pension insurance the farmer has paid over his active farming years. In order to predict the future development of the agricultural sector, farmers have been frequently asked about their future plans and their plans for succession. However, the plans the farmers made for succession have been found to be time inconsistent. This study estimates the value of farmers stated succession plans in predicting revealed succession decisions. A stated succession plan exists when a farmer answers in a survey questionnaire that the farm is going to be transferred to a new entrant within a five-year period. The succession is revealed when the farm is transferred to a suc-cessor. Stated and revealed behaviour was estimated as a recursive Binomial Probit Model, which accounts for the censoring of the decision variables and controls for a potential correlation between the two equations. The results suggest that the succession plans, as stated by elderly farmers in the questionnaires, do not provide information that is significant and valuable in predicting true, com-pleted successions. Therefore, farmer exit should be analysed based on observed behaviour rather than on stated plans and intentions. As farm retirement plays a crucial role in determining the characteristics of structural change in agriculture, it is important to establish the factors which determine an exit from farming among eld-erly farmers and how off-farm income and income losses affect their exit choices. In this study, the observed choice of pension scheme by elderly farmers was analysed by a bivariate probit model. Despite some variations in significance and the effects of each factor, the ages of the farmer and spouse, the age and number of potential successors, farm size, income loss when retiring and the location of the farm together with the production line were found to be the most important determi-nants of early retirement and the transfer or closure of farms. Recently, the labour status of the spouse has been found to contribute significantly to individual retirement decisions. In this study, the effect of spousal retirement and economic incentives related to the timing of a farming couple s early retirement decision were analysed with a duration model. The results suggest that an expected pension in particular advances farm transfers. It was found that on farms operated by a couple, both early retirement and farm succession took place more often than on farms operated by a single person. However, the existence of a spouse delayed the timing of early retirement. Farming couples were found to co-ordinate their early retirement decisions when they both exit through agricultural retirement programmes, but such a co-ordination did not exist when one of the spouses retired under other pension schemes. Besides changes in the agricultural structure, the share and amount of off-farm income of a farm family s total income has also increased. In the study, the effect of off-farm income on farmers retirement decisions, in addition to other financial factors, was analysed. The unknown parameters were first estimated by a switching-type multivariate probit model and then by the simulated maxi-mum likelihood (SML) method, controlling for farmer specific fixed effects and serial correlation of the errors. The results suggest that elderly farmers off-farm income is a significant determinant in a farmer s choice to exit and close down the farm. However, off-farm income only has a short term effect on structural changes in agriculture since it does not significantly contribute to the timing of farm successions.

Liikennepolttoaineeksi tarkoitettu ohraetanoli, Suomen ohramarkkinat ja ilmastonmuutos

The aim of the thesis was to analyze the use of barley as an input for bioethanol production and the impacts the use has on the Finnish barley markets. Two main research questions were formulated. First, privately and socially optimal bioethanol production levels were examined. In the social optimum, the climate benefits of bioethanol production were considered. It was calculated that the production and use of bioethanol created smaller CO2 -emissions when compared with the production and use of gasoline. Second, the impacts of bioethanol production on farmland allocation and agricultural production were analyzed. In more detail, the second aim was to analyze the farmland allocation between wheat and barley cultivation and green set aside in the private and social optimum. An analytical model was produced to analyze the barley markets in Finland. To provide an empirical counterpart to this model, existing research data on bioethanol production and barley cultivation was used. The aim of the model was to analyze the supply and the demand as well as market equilibrium of barley. Furthermore, the model provided a framework for analyzing the differences between the private optimum and social optimum of bioethanol production in Finland. The demand for barley consists of animal feed demand and bioethanol demand. On the supply side, a heterogeneous model of farmland quality was used. With this framework, it is possible to analyze farmland allocation between barley and wheat cultivation and green set aside and how the climate benefits of bioethanol production affects the allocation. Moreover, the relative changes in barley price between the private and social optimum were analyzed. Based on the empirical analysis, the private optimum for barley based bioethanol production is 58 691 metric tons. However, the social optimum for barley based bioethanol production is 72 736 metric tons. The portion of farmland that is allocated to barley cultivation is increased if the climate benefits of bioethanol production are considered. In the private optimum, 1/19 of the total farmland is allocated to barley cultivation whereas in social optimum the share increases to 7/19. Furthermore, the increase in barley price between private and social optimum is rather modest. Total increase in price is only about 1,8 percent.

Biochemical effects of the porphyrinogenic drug allylisopropylacetamide. A comparative study with phenobarbital

Successive administrations of allylisopropylacetamide, a potent porphyrinogenic drug, increase liver weight, microsomal protein and phospholipid contents. There is an increase in the rate of microsomal protein synthesis in vivo and in vitro. The drug decreases microsomal ribonuclease activity and increases NADPH–cytochrome c reductase activity. Phenobarbital, which has been reported to exhibit all these changes mentioned, is a weaker inducer of δ-aminolaevulinate synthetase and increases the rate of haem synthesis only after a considerable time-lag in fed female rats, when compared with the effects observed with allylisopropylacetamide. Again, phenobarbital does not share the property of allylisopropylacetamide in causing an initial decrease in cytochrome P-450 content. Haematin does not counteract most of the biochemical effects caused by allylisopropylacetamide, although it is quite effective in the case of phenobarbital. Haematin does not inhibit the uptake of [2-14C]allylisopropylacetamide by any of the liver subcellular fractions.

Monitoring healing progression and characterizing the mechanical environment in preclinical models for bone tissue engineering

The treatment of large segmental bone defects remains a significant clinical challenge. Due to limitations surrounding the use of bone grafts, tissue-engineered constructs for the repair of large bone defects could offer an alternative. Before translation of any newly developed tissue engineering (TE) approach to the clinic, efficacy of the treatment must be shown in a validated preclinical large animal model. Currently, biomechanical testing, histology, and microcomputed tomography are performed to assess the quality and quantity of the regenerated bone. However, in vivo monitoring of the progression of healing is seldom performed, which could reveal important information regarding time to restoration of mechanical function and acceleration of regeneration. Furthermore, since the mechanical environment is known to influence bone regeneration, and limb loading of the animals can poorly be controlled, characterizing activity and load history could provide the ability to explain variability in the acquired data sets and potentially outliers based on abnormal loading. Many approaches have been devised to monitor the progression of healing and characterize the mechanical environment in fracture healing studies. In this article, we review previous methods and share results of recent work of our group toward developing and implementing a comprehensive biomechanical monitoring system to study bone regeneration in preclinical TE studies.

Methodological issues with older users as research participants

Researching with older participants presents many unique methodological challenges. One of the reasons for this is the greater variability in abilities among older than among younger people. Thus, the standard practice in user research of assuming homogeneity in a certain demographic group may not work with older adults. Designing experiments for users with diverse capabilities is challenging and calls for re-examination of existing experimental design methods. In this paper we will share our experience in researching with people with diverse capabilities and present its implications and possible way to address them.

Get ready for a fruit fight: the fallout from Coles' price war on produce

Amid tough trading conditions and intense competition, Coles has fired the latest salvo in its ongoing supermarket war with Woolworths, announcing it will reduce the price of some fruit and vegetables by 50%. The move is the latest in a battle between the supermarket giants to wrest market share and follows previous cuts to staples such as milk and bread, beer and chicken. However, Australia’s peak industry body of vegetable growers, Ausveg, is concerned about the impact the price decision will have on growers' livelihoods.

Is pharmacy the final frontier for supermarkets?

Australia’s two major supermarket retailers, Coles and Woolworths, already have vested interests in fuel, convenience, liquor, hardware, hotels, apparel, general merchandise and technology. While they continue to battle each other for a share of the household food shopping dollar, pharmacy appears the final opportunity to grow their business.

FactCheck: is our grocery market one of the most concentrated in the world?

With one of the most concentrated food retail sectors in the world dominated by the supermarket duopoly, the barriers to making it easy to buy local food in Australia are significant. It is time for Australia to learn from the example of other countries and provide assistance to rebuild local food systems.” – The Australian Greens. However, the percentage of market share controlled by the two major supermarkets, Coles and Woolworths, depends on which groceries you include.

Who is the South African retail giant behind the David Jones bid?

Yesterday morning came the news South African retailer Woolworths had offered $4 a share to acquire David Jones, a proposal that has the approval of the department store’s board. This offer, worth an estimated A$2.15 billion, represents a 25% premium over the current share price value. An earlier offer, from rival Myer, was rejected earlier this year. But who is Woolworths? Not to be confused with Australia’s largest supermarket, Woolworths SA is one of South Africa’s largest retailers.

Woolies' new loyalty program offers a glimpse into the future

Woolworths is set to launch its new loyalty program, Woolworths Rewards, claiming that the new scheme will enable shoppers to redeem cash discounts off their shopping basket, much faster than ever before. It is estimated shoppers will acquire the necessary points to save $10 automatically of their grocery bill within seven weeks. Resembling the model used by UK retailer Morrisons, the new Woolworths Rewards program is a smart move for the retailer hoping to claw back some market share and curtail operational costs. However, there is no such thing as a free lunch.