Inference in disease transmission experiments by using stochastic epidemic models

Posted in: Welfare by admin on January 1, 2005 | No Comments

The paper extends the susceptible–exposed–infective–removed model to handle
heterogeneity introduced by spatially arranged populations, biologically plausible distributional
assumptions and incorporation of observations from additional diagnostic tests. These extensions
are motivated by a desire to analyse disease transmission experiments in a more detailed
fashion than before. Such experiments are performed by veterinarians to gain knowledge about
the dynamics of an infectious disease. By fitting our spatial susceptible–exposed–infective–
removed with diagnostic testing model to data for a specific disease and production environment
a valuable decision support tool is obtained, e.g. when evaluating on-farm control measures.
Partial observability of the epidemic process is an inherent problem when trying to estimate
model parameters from experimental data.We therefore extend existing work on Markov chain
Monte Carlo estimation in partially observable epidemics to the multitype epidemic set-up of
our model. Throughout the paper, data from a Belgian classical swine fever virus transmission
experiment are used as a motivating example.

ECONOMIC CONSEQUENCES OF BIOLOGICAL VARIATION: THE CASE OF MYCOPLASMA IN SWINE HERDS

Posted in: Production by admin on | No Comments

Problem Solving Feed Outages: Do we really know how often they occur and what impact they have?

Posted in: Production by admin on | No Comments

One of the problems with feed processing today is that small particles do not flow through feed mills, while larger particles reduce feed conversion efficiency. In order to assess the impact of feed outages, Kurt Stoess of Hytek analyzed the problem and determined to move the proximity switch and attach a binwhacker to whack the boot of the bin as the auger runs. This worked for a week until alarm calls began again. Plans of action need to be done for each individual farm. The first step is to record data in order to have a quantitative evaluation of the problem. From here, you can investigate problem areas, and implement strategies to overcome (or at least reduce!) the amount of problems.

Management interventions to help keep piglets alive in large litters

Posted in: Production by admin on | No Comments

The bulk of pre-weaning piglet deaths occur in the first 48 hours after birth. Therefore, close supervision and provision of optimum environmental conditions at this time can be very rewarding. Birth weight has a major influence on piglet survival and this can be maximized by optimizing parity profile and increasing feed levels to sows in late gestation. Overlying and crushings are major contributors to pre-weaning mortality. Closing piglets into the creep area for an hour each time the sow is fed in the first two days of life can help. When the rearing capacity of the sow cannot cope with excessively large litters, cross fostering should be carried out, where possible. Quality colostrum and a high milk yield by the sow are essential for piglet survival. Sow feeding during gestation and in lactation can influence the yield and quality of sows’ milk.

Equipment Considerations for On-Farm Feed Milling

Posted in: Production by admin on | No Comments

In the past 35 years, on-farm feed processing technology has progressed from portable mixer grinders and proportioner mills to very sophisticated, computerized, weight-based batching systems controlled by automation that rivals anything available on the commercial market. However, regardless of the type of mill you use for particle reduction, or the type of mixer or distribution system you incorporate, the results will reflect the level of management that is applied to the feed milling system. Proper maintenance, monitoring, and record keeping are critical. An on-farm feed mill, properly sized to your operation and feed demands, could be key in your ability to survive and remain competitive in the hog industry in the 21st century.

Statistical Evaluation of Classical Swine Fever Surveillance Plans in Italy (1995–2003)

Posted in: Production by admin on | No Comments

Surveillance plans were carried out in Italy from 1995 to 2003, with the main aim of controlling the possible circulation of low-virulence classical swine fever viral strains. The repetition
of a serological monitoring programme over several years, with constantly negative results, can prove the absence of the infection while increasing the degree of confidence. In our case, in 2003, after eight repetitions of the surveillance plan, the probability that there was at least one infected farm reached 0.006%. Therefore, on the basis of the results of the sampling carried out from 1995 to 2003, we may state that there is no endemic infection, even because of a low virulence virus, in
continental Italy.

Product quality attributes associated with outdoor pig production

Posted in: Production by admin on | No Comments

Inhibition of ovulation in the postpartum cow and the lactating sow

Posted in: Production by admin on | No Comments

Learn About Manure Management from MWPS

Posted in: Environment by admin on | No Comments

MidWest Plan Service now offers a set of educational materials geared toward helping farmers handle scrutiny of environmental practices in livestock production. The new curriculum provides answers, on-farm assessment tools, and optional record keeping forms for a wide range of manure management topics. It is available printed and gathered in a three-ring binder or as a searchable CD. The Livestock and Poultry Environmental Stewardship, or LPES, curriculum is made up of 26 lessons addressing how to achieve high environmental standards through nutrient management, animal dietary strategies, manure storage and treatment, land application, and outdoor air quality.The LPES team also has recently released a series of 24 fact sheets on the new Environmental Protection Agency regulations for Concentrated Animal Feeding Operations (CAFOs). Each addresses a common producer question with a non-technical review of the regulations and recommendations for compliance. Copies of the LPES CD and notebook, as well as the CAFO fact sheets can be purchased from MidWest Plan Service. You can order online through the catalog section of the MWPS Web site at www.mwpshq.org

The effect of socioeconomic factors on the adoption of best management practices in beef cattle production

Posted in: Environment by admin on | No Comments