Elevated platforms with integrated weighing beams allow automatic monitoring of usage and activity in broiler chickens
Elevated platforms are a suitable possibility to enrich the environment of broiler chicken and, thus, improving their welfare. Early detection of health problems additionally contributes to an improved welfare of chickens and, at the same time, helps the farmer to optimize production efficiency. A prototype combined elevated platforms with weighing beams and an algorithm was developed to estimate number of chickens on the platform as well as their activity. To validate the prototype, during two consecutive trials, 1200 mixed-sex broiler chickens were kept for 35 days in 6 pens in total. In each pen, an elevated platform (height x length x width: 0.5 m x 4 m x 0.6 m), consisting of two rectangular steel frames and four load cells, was offered. Overall weight of broilers on the elevated platform was recorded continuously during the entire fattening period by the automatic weighing system. Algorithms were developed and implemented to estimate (i) daily mean weight of a single animal, (ii) number of animals on the platform, and two activity measures: (iii) movement on platform and (iv) number of platform changes from the weight recordings. To validate estimations, weight was recorded manually on 5 days throughout the trial and usage of elevated platforms was analysed via video records with scan sampling. From days 4 to 34, daily mean weight could be estimated using the proposed algorithm. Compared to manual weighing of a sample group at five days per pen, Spearman correlation coefficient was given by 0.9868 (p < 0.0001), and estimation error (RAE) was 11 % on average. The number of chickens on the elevated platform could be approximated with deviations of about +19 % and Spearman correlation of 0.97 (p < 0.0001) compared to video observations. An explanation for overestimation of animal number are occasional recalibration problems of the weighing system that resulted in measured weights being larger than actual weights. Furthermore, results of automatic approximation of usage behaviour and animal activity based on continuous recordings of the weighing system throughout days 4 to 34 of fattening are shown. In addition to providing an enrichment tool that could help farmers to control weight development of their livestock automatically and continually, first promising observations of anomalies due to heat and illness show that the proposed system could be used for early detection of animal welfare problems.