S.M. Ward

Development of a DNA-based assay for species identification in meat and bone meal

Abstract Restrictions on the use of meat and bone meal (MBM) as a feed ingredient were introduced by the European Commission as a result of the BSE crisis. This paper describes the development of species specific PCR assays to detect bovine, ovine, porcine and poultry species content in MBM. A simple lysis based extraction procedure and a commercial DNA extraction kit were evaluated using simulated samples of rendered material for performance in terms of yielding DNA that is amenable to PCR amplification. From a small cohort of commercially produced samples (n=7) the application of species specific PCR assays was used to determine the species content of these samples returning an accuracy of 72.5 and 60% for the two selected extraction procedures. Using the simple lysis method, with single species rendered material, a inclusion rate of 0.3% for the bovine and ovine primers and 1% for the porcine primers in MBM containing another reference species was detectable.

Behaviour of meat and bonemeal/peat pellets in a bench scale fluidised bed combustor

As a result of the recent Bovine Spongiform Encephalopathy crisis in the European beef industry, safe animal by-product disposal is currently being addressed. One such disposal option is the combustion of by-product material such as meat and bone meal (MBM) in a fluidised bed combustor (FBC) for the purpose of energy recovery. Two short series of combustion tests were conducted on a FBC (10 cm diameter) at the University of Twente, the Netherlands. In the first series, pellets (10 mm in diameter and approximately 10 mm in length) were made from a mixture of MBM and milled peat, at MBM inclusion rates of 0%, 30%, 50%, 70% and 100%. In the second series of tests, the pellets were commercially made and were 4.8 mm in diameter and between 12 and 15 mm long. These pellets had a weight of about 0.3 g and contained 0%, 25%, 35%, 50% and 100% MBM inclusion with the peat. Both sets of pellets were combusted at 880°C. The residence times in the FBC varied from 300 s (25% MBM inclusion) to 120 s (100% MBM inclusion) for the first series of pellets. Increasing compaction pressure increased the residence time. For the second series of pellets, the residence time varied from about 300 s (25% MBM inclusion) to 100 s (100% MBM inclusion). MBM was found to be a volatile product (about 65%) and co-firing it with milled peat in a pelleted feed format reduces its volatile intensity. Pellets made from 100% bone based meal remained intact within the bed and are thought to have undergone a process of calcination during combustion. A maximum MBM inclusion rate of 35% with milled peat in a pellet is recommended from this work.

RESULTS OF ENGINE AND VEHICLE TESTING OF SEMIREFINED RAPESEED OIL

The renewed interest in environmentally compatible fuels has led to the choice of rapeseed oil as the main alternative to diesel fuel in Europe. Transesterified rapeseed oil (viz. rape methyl ester) has been the predominant vegetable oil fuel used because its characteristics are quite similar to diesel. However, it is an expensive product due to high feedstock costs. The objective of this research was to produce and test an economic and high quality nonesterified rapeseed oil suitable for use as a diesel fuel extender. This was achieved by acidified hot water degumming combined with filtration to five microns. This rapeseed oil, designated as a Semi Refined Oil (SRO), has a high viscosity in comparison with diesel (589 mPa·s vs 22 mPa·s at –12°C). Hence, SRO fuel can be used only as a diesel fuel extender at inclusion rates up to 25%, the resultant blend having a viscosity of 55 mPa·s at –12°C. When used with direct injection (DI) engines, power output (at 540 rpm at the power take-off shaft) was reduced by c. 0.06% for every 1% increase in SRO inclusion rate, and brake specific fuel consumption (BSFC) increased by c. 0.14%/1% increase in SRO inclusion rate (viz. a 25% SRO/diesel blend had a 1.5% decrease in power and a 3.5% increase in BSFC compared with diesel). These values are in accordance with the lower energy density of rapeseed oil fuels compared with diesel. Chemical and viscosity analyses of engine lubrication oil using both diesel and a 15% SRO inclusion rate (after c. 170 h/fuel tested), including metal contamination as an indicator of engine wear, showed that there was no measurable effect on engine lubricating oil due to SRO inclusion in diesel oil. However, the injector fouling results showed that shorter injector service intervals are required. In contrast to the DI results, above, when SRO was used to fuel indirect injection (IDI) engines, power was considerably reduced mainly due to inadequate air/fuel mixing. As most agricultural tractors are DI, SRO has a potential as a diesel fuel extender for agricultural equipment.

The radiometric normalization of multitemporal Thematic Mapper imagery of the midlands of Ireland: a case study

Two Landsat Thematic Mapper (TM) scenes of the same area of the midlands of Ireland were required to be radiometrically normalized. Standard techniques were reviewed and considered unsuitable. A hybrid approach was adopted that used linear transformation functions. As part of this approach, a novel thresholding-based method for extracting reference data from a land cover class with sub-pixel scale elements was developed. This method was shown to be robust with a consistency of ca - 1 digital number (DN) being achievable in the extracted reference data. A procedure for removing pixels influenced by thin cloud and associated shadow was included. The radiometric normalization approach produced acceptable Root Mean Square Errors in the range 0.8-2.5 DN. Whereas the strategies and methodologies developed were appropriate to the particular environment, the developmental process may serve as a template for analysts working in similar environments elsewhere.

Using Muzzle Pattern Recognition as a Biometric Approach for Cattle Identification

Arising from the current need for positive identification for cattle traceability, the objective of this work was to investigate the feasibility of using muzzle pattern as a biometric-based identifier for cattle by acquiring muzzle patterns through lifted ink prints and through digital images. A three-stage matching algorithm was evaluated for scanned muzzle ink prints and performed successfully in all cases. Digital imaging of muzzles was far simpler than the ink print lifting method. For these digital images, the techniques of principal component analysis and Euclidean distance classifier were used. The algorithm training was performed independently on a different number of normalized muzzle images from 29 cattle (sets of 2, 4, 6, 8, and 10 training images per animal). The performance of this technique was assessed on a separate set of images (3 normalized muzzle images per animal). Results showed that when using 230 eigenvectors (out of 290), the recognition rate was 98.85%, and that additional eigenvectors did not improve the recognition rate. As expected, fewer principal components (less than 230) reduced the recognition rate, while a higher number of training images per animal improved it. Although the results have demonstrated the potential of muzzle pattern recognition as a non-invasive, inexpensive, and accurate biometric identifier of cattle, further research towards automation is necessitated.

Repair Costs of 2 and 4 WD Tractors

ABSTRACT FIELD data on the repair costs of both two and four wheel drive tractors is presented. The tractors were used for general purpose forestry work (viz. trailer transportation, hedge trimming, grass mowing and some miscellaneous tasks); and the repair costs obtained were higher than previous literature estimates. For example, after 6 000 h of work, a two wheel drive tractor has an accumulated repair cost equivalent to 70% of the original purchase price, while the nearest estimate from other sources is 46%. In addition, four wheel drive tractors were found to have marginally higher repair costs than two wheel drive tractors - this is in direct contrast to other sources. It was concluded that the inclusion of this data in system cost models would result in a reduction in the recommended tractor replacement age and an increase in overall system costs.

A preliminary investigation on face recognition as a biometric identifier of sheep

The suitability of face recognition was investigated as a biometric-based identifier for sheep using a holistic analysis of face images by the independent components technique. Algorithm training was performed independently on several normalized face images from 50 sheep (sets of two, three, and four training images per sheep). The performance of this technique was assessed on a separate set of images (three normalized face images per sheep) using the cosine distance classifier. When 180 to 200 components were extracted, the recognition rate was as high as 95.3% to 96%. As expected, fewer independent components reduced the recognition rate, while a higher number of training images per sheep improved it. Although our results have demonstrated the potential of face recognition as a non-invasive, inexpensive, and accurate novel biometric identifier of sheep, further work should aim at improving recognition rates on a larger set of sheep faces.

A Method For Relating GPS Performance To Forest Canopy

Abstract This paper describes the development of a quantitative method of classifying forest canopy that can be related to degradation in Differential GPS (DGPS) performance. Using digital images taken vertically skywards at 20 sites within a forest on the east coast of Ireland, canopy cover was described using percentage sky obstruction (Op ), largest hole (DTmax ), and the fragmentation of sky view (DTp ) using pixel count and distance transform data. Statistical methods were used to produce three clusters which related to canopy cover in stands of Picea sitkensis and Picea contorta. DGPS data were then collected on 10 separate dates at the 20 sites, every two seconds for five minutes, and the two–dimensional standard deviation of the position fix was used to represent DGPS precision. The standard deviations ranged from 0.5 m to 9.7 m (compared to the manufacturer’s specification of approximately 1 m in the horizontal). Precision was found to be related to the total obstruction, the size of the largest hole in the canopy, and the fragmentation of the sky view. Where there was little obstruction (<20%) or fragmentation, the DGPS performance was effectively the same as outside the forest, open canopy caused a 2–3 fold degradation in precision, and closed canopy a 5–7 fold degradation. It is suggested that the methods presented could be used to rapidly relate DGPS performance to forest canopy, and therefore may be useful in pre–planning inventory mapping and future machine operations using guidance systems.

Predictive modelling and risk assessment of BSE: a review

Predictive models have been used to monitor and analyse the future course of bovine spongiform encephalopathy (BSE) and provide estimates of biological parameters to assess the risks to both animal and human health. Risk assessment models have illustrated that oral transmission is the primary cause of BSE (90% of cases) and have shown that horizontal transmission of infection may be responsible for the persistence and clustering of the disease. Best-fit risk assessment models have shown that maternal transmission occurs at a rate of 9.6% with 95% confidence limits of 5.1–14.2. There is an age-dependent susceptibility to infection. Risk models have estimated that bovine susceptibility to BSE, and hence risk of infection, peaks at 1.31 years of age and rapidly decreases in subsequent years. An animals infectiousness (and hence risk to cause disease) is mainly confined to the end of the incubation period with a peak when clinical signs appear. BSE models have shown that the optimal culling policy to minimize BSE cases is a combination of herd targeting plus a policy that targets bovines potentially exposed through the maternal transmission route. Back calculation methods have concentrated primarily on epidemiological parameter estimation while other risk assessment modelling techniques have focused on predictive studies and on the evaluation of different BSE control strategies. Predictive modelling and risk assessments have enabled a more accurate description of the underlying parameters effecting BSE disease incidence and the associated risks.

Productivity and Cost of Mechanized Whole-Tree Harvesting of Fast-Growing Eucalypt Stands

Abstract The performance of alternative equipment for the whole-tree harvesting of eucalypt stands was evaluated, using data from five different commercial operations. The study covered three machines for felling and bunching, two for extraction (skidding), and two for combined delimbing, debarking and chipping. Productivity and operating cost models were evaluated for each of the machines, in order to estimate the net harvesting costs under varying forest stand and site conditions. It was found that under easy terrain conditions (flat terrain, dry ground), trees should be felled by threewheeled feller-bunchers and extracted by front-end loaders, as this combination had the lowest harvesting costs. Due to mobility limitations, this equipment may have to be replaced by tracked feller-bunchers and conventional skidders in steep terrain and/or soft ground. It was estimated that the cost of using the wheeled feller-buncher and the front-end loader system ranged between 16–22