Barbara Sturm

Using machine vision for investigation of changes in pig group lying patterns

Group pig lying change detection using Delaunay triangulation is presented.Ellipse fitting algorithms were used to localize each pig body in the image.Delaunay triangulations were changed as the room temperature increased.Pig lying location is determined through ellipse centroids in the pen. Pig lying patterns can provide information on environmental factors affecting production efficiency, health and welfare. The aim of this study was to investigate the feasibility of using image processing and the Delaunay triangulation method to detect change in group lying behaviour of pigs under commercial farm conditions and relate this to changing environmental temperature. Two pens of 22 growing pigs were monitored during 15days using top view CCD cameras. Animals were extracted from their background using image processing algorithms, and the x-y coordinates of each binary image were used for ellipse fitting algorithms to localize each pig. By means of the region properties and perimeter of each Delaunay Triangulation, it was possible with high accuracy to automatically find the changes in lying posture and location within the pen of grouped pigs caused by temperature changes.

Automatic detection of mounting behaviours among pigs using image analysis

Automatic mounting events detection among pigs is presented.Ellipse fitting algorithms were used to localize each pig in the image.The Euclidean distances between head, tail and sides of pigs were obtained.Major and minor axis lengths were altered during mounting events. Excessive mounting behaviours amongst pigs cause a high risk of poor welfare, arising from skin lesions, lameness and stress, and economic losses from reduced performance. The aim of this study was to develop a method for automatic detection of mounting events amongst pigs under commercial farm conditions by means of image processing. Two pens were selected for the study and were monitored for 20days by means of top view cameras. The recorded video was then visually analysed for selecting mounting behaviours, and extracted images from the video files were subsequently used for image processing. An ellipse fitting technique was applied to localize pigs in the image. The intersection points between the major and minor axis of each fitted ellipse and the ellipse shape were used for defining the head, tail and sides of each pig. The Euclidean distances between head and tail, head and sides, the major and minor axis length of the fitted ellipse during the mounting were utilized for development of an algorithm to automatically identify a mounting event. The proposed method could detect mounting events with high level of sensitivity, specificity and accuracy, 94.5%, 88.6% and 92.7%, respectively. The results show that it is possible to use machine vision techniques in order to automatically detect mounting behaviours among pigs under commercial farm conditions.

Effect of maturation and freezing on quality and drying kinetics of beef

ABSTRACT The quality of dried meat products and their drying kinetics significantly depends on the status of the raw material going into the drying process. The aim of this study was to determine the impact of meat status (fresh, mature, frozen–thawed) on the drying kinetics and the resulting quality in terms of color changes and spectrally deductible information. Drying tests were conducted using meat from organically raised bulls. In the fresh meat, freezing leads to a decrease in the drying rate, while for matured meat, the opposite is true. Aging and freezing have little effect on the end product quality in terms of final product color. However, water content can be detected hyperspectrally and resolved spatially for all stages of the process. With regard to water content prediction, the Monte-Carlo uninformative variable elimination-partial least square method performs best for the fresh and fresh frozen–thawed version with seven wavelengths, an r2 of 0.97 and 0.88, and RMSE (Root mean squared error) of 0.15 and 0.17 for the test set, respectively.

Drying behavior and quality parameters of dried beef (biltong) subjected to different pre-treatments and maturation stages

ABSTRACT The drying behavior of fresh, matured, and frozen beef, marinated with 0.5% salt, 1% salt, salt and vinegar, and blind samples, dried at 70°C, was investigated. Weight and color (CIELAB) were measured and images of the samples were created with a hyperspectral imaging camera. Results show that the marinade and the type of beef influences the drying behavior of beef, but not the final color. Results from the hyperspectral imaging show that it is possible to build good fitting prediction models resulting in high R2 (min. 0.81, max. 0.98) and low RMSE (min. 0.08, max. 2.35) for moisture content, a* and b* values.

Strategies and Technologies for Camel Milk Preservation and Utilization of Non-Marketed Milk in Arid and Semi-Arid Areas

ABSTRACT This study determined the seasonal fluctuations in camel milk yield, consumption, spoilage and spillages, and explored its forms of consumption and the acceptability of camel milk powder in Isiolo County, Kenya. In addition, the utilization of non-marketed milk, preservation technologies, and strategies for milk loss reduction employed along the camel milk supply chain were examined. Quantitative data was collected from 216 respondents (producers, traders and transporters) using a structured questionnaire while qualitative data was collected through participant observations, key informant interviews and focus group discussions involving the camel milk supply chain participants. For quantitative data, descriptive and inferential analyses were conducted whereas for qualitative data thematic analyses were utilized. Camel milk yield, consumption, spoilages and spillages increased by 45.5%, 40%, 81.0% and 79.1% respectively in the wet season. Camel milk was often consumed in smoked and boiled forms or as tea but never in pasteurized or powder form. Transportability, affordability and shelf life were mentioned as important attributes for camel milk powder acceptability. For non-marketed milk, 28.8% and 9.0% was discarded in the wet and dry seasons respectively while 11.2% and 22.4% was processed. The main strategies employed for milk loss reduction were: maintenance of hygienic practices (88% producers, 61% traders), smoking of the milk handling equipment (68% producers, 10% traders), and simple cooling (13% producers). High cost and limited technical feasibility restricted the utilization of preservation technologies (chilling and refrigeration). These findings show the need for appropriate milk preservation technologies for longer shelf life of milk products in arid and semi-arid areas.