Search

Animal behaviour is complex and comparing average levels of behavioural activities is sometimes insufficient to pick up on behavioural differences between (groups of) animals. Entropy, a measure of the randomness or regularity of time series, might help us to describe aspects of behaviour better. In this study, we determined daily entropy in individual broiler activity levels over time, based on a time series of observed activity per 15 minutes across a day, to assess individual variation and consistency in entropy of activity. Activity data for calculation of entropy were available for 79 broilers for a maximum of 21 days. We observed individual variation in entropy between broilers, but the level of entropy was not very consistent across days. The individual variation in entropy indicates potential for future research to look into whether and how entropy differences relate to other traits in broilers.

Individual activity is related to the health, welfare and performance of broilers. In previous work using a radio frequency identification system, we were able to collect individual activity data over time, and activity was found to be heritable. The aim of the current study was to estimate genetic parameters for activity while taking into account the effect of age. Therefore, two repeated measurement models were fitted. The model with an intercept and slope for genetic and permanent environmental effect, and a heterogeneous residual variance, yielded the best goodness-of-fit. First results showed that daily heritability varied between 7 and 30%. The heritability was lowest at the start and at the end of the production life. This study shows potential for selection on activity in broilers. Furthermore, this study shows that activity patterns (in time) can be changed, as both the intercept and slope of activity are heritable.

A bibliometric analysis was performed to explore to what degree published animal breeding studies (on cattle, pigs and poultry) explicitly address societal issues and ethics, and what themes were addressed. A combination of search terms in Scopus resulted in about 24,500 publications on farm animal breeding since 1990, of which 673 included a society- or ethics-related term. A two-person manual second (on titles) and third (on the title, key words and abstract) selection step reduced the number to 270 papers that met our criteria, so overall, about 1% of the identified published animal breeding studies explicitly refers to themes being a societal issue in the title, key words or abstract. The number of papers per publication year increased rapidly after the year 2001, and peaked around 2010. Animal welfare and behaviour (AW) was the trait that was addressed most, especially for poultry, and to a lesser extent also for pigs and cattle. Explicit reference to ethics was made in 65 (24%) of the 270 selected papers. In this ‘explicit on ethics’ subset, the themes genetic modification (GM), biotechnology (BT) and AW were dominant. The subset of studies on GM that explicitly mentioned ethics was assessed in more detail, to examine how, and to what extent, the topic of ethics was discussed, and whether specific actions were mentioned. The inclusion of ethics in these publications varied along a broad spectrum, ranging from ethics only being mentioned as being relevant to ethics being the main topic of the paper. Several studies called upon different stakeholders to take action, mainly in terms of actively taking part in discussions. This study concludes that: (1) the human eye/brain seems to be necessary to select on criteria in a bibliometric study like the present – the visual inspection removed about 60% of the ‘hits’ for being false positive; (2) animal breeding work on AW issues seems to be more prone to use wording that is explicit on societal issues compared to breeding work on other sustainability issues; (3) studies on BT, GM and AW are the main categories containing explicit reference to ethics, papers on other themes mention ethics to a considerably lesser extent; and (4) between the studies on GM that explicitly mention ethics, there is substantial variation in how they deal with ethical reasoning.

Individual broiler behaviour could serve as a proxy for an individual’s health, welfare and performance. However, large-scale individual behaviour recording is difficult. Wearable and remote sensors have both been investigated to record individual broiler behaviour. In this study, we validated the use of automated tracking using video or radio frequency identification (RFID) by comparing the total estimated walking distance to ground-truth annotated from video. By using colour-marked birds we simplified the computer vision task of YOLOv5. The estimated walking distances by video pixel-based closely matched ground-truth pixel-based (≤2 cm difference). Overall, the RFID-system also closely matched ground-truth pixel-based, except for one movement event (75 cm underestimation). Over the entire duration of the trial, RFID and video gave similar animal rankings, but RFID seems more error prone due to missing reads. RFID is suitable to track broilers over time, but video could be more accurate and practical for on-farm application.

Societal and ethical issues addressed in animal breeding studies from 1990 onwards were examined by means of a bibliometric analysis. Using a specific set of search terms in Scopus, 673 publications of potential interest for societal aspects of animal breeding were found. Subsequent manual selection resulted in 270 relevant studies. Across the period from 1990 to the present, the number of publications addressing societal or ethical aspects of animal breeding, mainly focussing on animal welfare and behaviour or genetic modification, increased from the year 2000 and peaked around 2010. Of the 270 publications, 24% explicitly mentioned ethics, mainly in relation to genetic modification, biotechnology or animal welfare/behaviour. The minority of the publications (32%) were experimental studies. To conclude, only a minor part of publications on animal breeding explicitly address societal issues and, of these, the minority explicitly addresses ethics.

To track and monitor individual animals in groups, it is possible to use radiofrequency identification (RFID) systems. RFID encompasses all wireless communication systems that use radiofrequency fields [1]. RFID systems consist of tags and readers [2]. The tags contain unique identification data and can be attached to the item or, in the proposed application, to the animal that needs to be tracked [2]. The readers are used to read and identify the tags via radiofrequency fields [2]. The development of RFID technology started in the late 1960s and RFID systems are currently used for a large range of applications, including electronic door locking systems, contactless smart cards, and animal identification [2,3,4]. Further progress in the technology of chip manufacturing now makes RFID suitable for novel applications and available at a lower cost [4,5]. Therefore, the existing RFID technology may be applicable for animal tracking and monitoring as well. Here, different types of RFID systems will first be discussed for their applicability in individual animal tracking and monitoring, after which future work using RFID to track individual animals will be presented.

The resolution of racemates through their diastereomeric salts can be positively affected by the addition of small amounts of suitable nucleation inhibitors. This discovery is a logical extension of "Dutch Resolution", in which equimolar amounts of resolving agents that are members of the same family (i.e., structurally related) are used. We conducted a systematic search for nucleation inhibitors of the resolving agent 1-phenylethylamine. A wide range of amines that bear possible family resemblances to 1-phenylethylamine was investigated. It was found that (R)-1-phenylbutylamine is a good inhibitor of (R)-1-phenylethylamine. Results of turbidity measurements showed that, for the model case of mandelic acid resolution, the chief effect of this inhibitor was to widen the metastable zone for the more soluble diastereomer. This observation is in accordance with previous experience. Further scouting for possible family members revealed a wide variation in the effectiveness of inhibitors, dependent on their structure. By far the most effective inhibitors are bifunctional 1-phenylethylamine and/or 1-phenylbutylamine analogues. The effect of racemic inhibitors was found to approach that of enantiomerically pure inhibitors of the same absolute configuration of the 1-phenylethylamine used for resolution. The most effective inhibitors were tested for the resolution of a structural variety of racemates, and were shown to be broadly applicable.