A model for estimating how variability of biological parameters affects economic factors in an integrated turkey farm

Turkeys, as well as other poultry meat, are marketed as a healthier alternative to red meat. At the same time, the necessary investment in integrated turkey projects is 65% higher than for similar broiler projects. This explains the importance of rigorous evaluation of new turkey farms, including their sensitivity to biological parameters. We present a method of evaluating poultry projects that takes simultaneous variability of several biological parameters into account, using a bio-economic model, stochastic simulation, and an integrated turkey farm in Russia as a real-life example. The algorithm based on the Cholesky decomposition of the covariance matrix was used to generate a multivariate normal random vector of biological parameters. The bio-economic model takes into account simultaneous variability of major input biological parameters related to all stages of an integrated poultry farm: survival, hatchability, ratio of carcass weight to live weight, and number of eggs per layer. The highest variability of the output economic indices was estimated for internal rate of return: the coefficient of variation (CV) of this major economic index was approximately 240% of the CV of the input biological parameters. Such estimation can be used to analyze a project's economic risks, i.e., variability in production cost and profitability.     

Evaluating innovative technologies for multistage fish growth processes: Case study of an eel (Anguilla anguilla L.) farm

A new method for evaluating innovative technologies for multistage fish growth processes was developed. An earlier economic model was adapted to meet the real-world requirements of a commercial eel (Anguilla anguilla L.) farm. The economic benefits of different innovative technologies at the farm level were evaluated where the technology included multiple production alternatives at various intensities and several growth stages. Data were gathered into “bio-economic” tables that take into account the biological parameters of each production alternative and the costs related to its development and implementation. The adjusted data were then divided into groups of production alternatives and feasible combinations of alternatives for each of three growth stages were evaluated to determine the best technology for the overall growth process. A computer program enabled us to enumerate all potential innovative technologies, collect information on biological parameters and costs by growth stage, and compare additional profit expected after implementation of each innovation. Results reveal the most profitable innovative technologies by growth stage for the 5-year eel culture. Comparison of the 10 best technologies shows that combining the alternatives with the best biological parameters for each growth stage does not necessarily result in the maximum additional profit for the farm.     

黄芪种衣剂对2年生黄芪生物量的影响

通过黄芪进行种衣剂包衣处理,以ND牌种衣剂包衣和空白种子为双对照,比较研究在不同处理条件下,黄芪种衣剂对2年生膜荚黄芪植物生物性状以及生物量的影响.结果表明:黄芪种衣剂包衣处理后,在生物产量方面,黄芪种衣剂处理组在第2年的生物量增长好于对照,表明黄芪种衣剂在第2年时仍然对植株生物量的增长发挥作用.     

Evaluation of aggregate stability of Haplic Stagnosols using dynamic light scattering,phase analysis light scattering and color coordinates

Dynamic light scattering and phase analysis light scattering have been used to study organo-clay complexes and aggregate stability of Haplic Stagnosols depending on land use. The study of agricultural soils afforested for 45 years showed that the value of the effective diameter of organo-clay complexes slightly decreased compared to that in arable soil but remains still higher than that in the forest soil. Multiple linear regression statistical models were developed to predict the effective diameter of the particles. The best model (r = 0.95), where all parameters were significant (P < 0.05), included the clay content, clay carbon concentration, total iron (Fe_t) and soil color coordinates (L*, a*, b*). In the upper horizons, the effective diameter depends on the organic matter content, whereas iron oxides with surfaced position play the main role in the underlying horizons. Intensive tillage moves the colloidal system to coagulation and after withdrawal of arable Haplic Stagnosol from the agricultural production, the colloidal system tends to restore its peptization stability. However, it should be noted that the afforestation period (45 years) of arable Haplic Stagnosols is not enough for a full recovery of organo-clay complexes peptization stability.     

Distribution of the larch brown rust caused byTriphragmiopsis laricinum (Uredinales) in Russian Far East

The larch brown rust caused byTriphragmiopsis laricinum was found onLarix cajandri in Primorsky Territory, Russia. This was a new host and locality record for the pathogen. Preliminary survey of the disease incidence in several localities in East and Northeast Russia and Yakutia-Sakha Republic indicated the restricted distribution of the rust in a few localities in Primorsky Territory. As previously reported in China,T. laricinum was proved to form uredinia in nature and to be able to propagate vegetatively by urediniospores. This suggests the fungus could become a devastating pathogen threatening a large-scale larch plantation in Far East of Russia. Field observations and the failure of basidiospore inoculation onto larch needles suggest the heteroecious life cycle ofT. laricinum.     

Control of carbohydrate utilization by soil microflora

The control mechanisms regulating the utilization of carbohydrates by soil populations were examined. Glucose, fructose, galactose, lactose, cellobiose and xylose were added to the soil either separately or in combination with glucose and the formation and activity of enzymes catabolizing the individual carbohydrates were studied. No specific repression of the formation of carbohydrate-degrading enzyme by glucose was observed in the soil. The activity of galactose-degrading enzymes was inhibited in the presence of glucose, resulting in a sequential utilization of the two sugars. Similarly, the rate of utilization of lactose and, in part, of cellobiose was inhibited in the presence of glucose. The activity, rather than the synthesis, of the enzymes was thus inhibited by glucose; the inhibition was reversible.