Mikaela Mughal

Evaluation of the confusion matrix method in the validation of an automated system for measuring feeding behaviour of cattle

The aim of the present study was to evaluate empirically confusion matrices in device validation. We compared the confusion matrix method to linear regression and error indices in the validation of a device measuring feeding behaviour of dairy cattle. In addition, we studied how to extract additional information on classification errors with confusion probabilities. The data consisted of 12 h behaviour measurements from five dairy cows; feeding and other behaviour were detected simultaneously with a device and from video recordings. The resulting 216 000 pairs of classifications were used to construct confusion matrices and calculate performance measures. In addition, hourly durations of each behaviour were calculated and the accuracy of measurements was evaluated with linear regression and error indices. All three validation methods agreed when the behaviour was detected very accurately or inaccurately. Otherwise, in the intermediate cases, the confusion matrix method and error indices produced relatively concordant results, but the linear regression method often disagreed with them. Our study supports the use of confusion matrix analysis in validation since it is robust to any data distribution and type of relationship, it makes a stringent evaluation of validity, and it offers extra information on the type and sources of errors.

Inter-observer reliability of animal based measures in the Welfare Quality protocol for dairy cows

Antibiotic (AB) resistance is a major concern worldwide. Knowledge about potential drivers of AB use and prescribing practices in the pig industry is required to address problems of mis and over use. We hypothesised that pig farmers attitudes towards the treatment and care of injured or sick pigs may influence their use of AB. Semi-structured face-to-face interviews were conducted with 30 producers who managed integrated pig units in Ireland and which supplied records to the Teagasc PigSys database. Ethical approval was obtained and pig producers were invited for interview by their Teagasc pig advisor. Consent was obtained at the time of the interview. Interviews with participants were recorded and transcribed using random numbers from 1 to 30, one per participant to ensure anonymity. Themes were then identified from the data. The importance of comfort and care in the rehabilitation of animals following injury was only expressed in relation to sows. Here the importance of straw bedding and a solid floor in ensuring recuperation from lameness/injury was mentioned by several producers (n=7). The relevance of analgesics to recovery from illness or injury was only mentioned by 2 producers who used pain relief for sows that were ‘sick after farrowing’. Injectable ABs were the most common method of treating illness or injury (n=12), followed by euthanasia (n=7). The practice of euthanising pigs was driven by economic (n=6) or humane grounds (n=9). The latter also expressed the belief that it was more humane to euthanise than to hospitalise sick or injured pigs. However, there was a general dislike for the practice of euthanasia. Many producers mentioned that it is too expensive to call a vet to treat or to euthanise sick or injured pigs. Only one producer used a vet to euthanise pigs. Several producers did not agree with the use of hospital pens (n=7) either because they believed that pigs are usually abandoned/forgotten in such pens (n=2) or because hospital pens are places where diseases are harbored and recirculated through the herd. Almost half of the producers expressed the view that medications (in-feed and/or injections) were the only solution to deal with pig health problems and to ensure good welfare. A 3rd of producers believed that the only solution to serious diseases challenges was to de-stock the herd. Low profit margins and lack of awareness of the role which husbandry and the environment have to play in the prevention of diseases as well as the role which comfort and care of pigs play in the recovery process are major barriers to reducing the reliance on medication in the pig industry