Skip to main content
European Commission logo print header

The potential of behavioral play markers to improve welfare in farm animals through selection

Final Report Summary - SELECTIONFORWELFARE (The potential of behavioral play markers to improve welfare in farm animals through selection)

In livestock species, breeding goals are aimed primarily at improvement of production traits. However, there are a number of examples where selection for high production efficiency has resulted in reduced welfare through unfavorable outcomes in health and fitness characteristics. This has raised questions about what is ethically acceptable in animal breeding. As a result, there is a growing interest in the potential practical, economic and ethical issues of genetic selection for behavior in addition to that for production traits.
In farm animals, heritabilities have been estimated for a number of behavioral traits, such as aggression, sociality, stereotypy, fear and maternal behavior. Play behavior has been proposed as a new and promising potential indicator of animal welfare. Animals play only if they are healthy, safe, well-fed and in a relaxed state, but not if they are under a stressful condition. Therefore, play behavior can be used as an indicator of animal welfare. To date, very little information is available on play behavior in animal production systems.
The goal of the study is a multi-disciplinary investigation into the phenotypic expression and the genetic background of play behavior in piglets, to investigate the possibility to include a measure of play behavior in the breeding goal, and to investigate the phenotypic and genetic relationship between play behavior, and animal production traits and welfare. The multidisciplinary project integrates animal behavior and welfare with genetics, nutrition, reproduction and physiology.
Breeding for behavior presents a number of serious challenges, and breeding for welfare even more. It is difficult and time-consuming to directly measure behavior in a consistent and reliable manner which is necessary to evaluate the large numbers of animals that are necessary for a breeding program. In addition, the major obstacle to overcome before genetic solutions can be implemented is determining which trait(s) to select for in order to truly improve animal wellbeing, either through direct measurements or through indirect measurements that are strongly correlated. Therefore, the major challenge of this research is the acquisition of photographic and film images that are analyzed with special programs to provide objective measurements on play behavior in different contexts. Play behavior is categorized as social, object or locomotor play. Social play involves two or more animals and allows animals to develop social skills and to facilitate their integration into groups. Object play involves activity devoted to an inanimate object and is related to the development of motor skills. Locomotor play involves jumping, running and performing other motor activities in a sudden, persistent and frenetic manner and is related to physical development. All three situations are investigated in this study.
Several experiments have been performed in order to address the objectives of this study. A first study was aimed at investigating the ability of the video recording material and handling of the litter during the process which included individual recognition. In a following experiment, piglets were followed between birth and weaning at 42 days of age. Piglets were weighed approximately twice a week and body weight gain was estimated over this period. Animals were marked and recorded twice a day with an overhead video recording system. Data is analyzed visually for play behavior; in addition, behavior will be analyzed with video tracking software for activity. After weaning, piglets were introduced to a novel object, object play behavior was recorded and animals were introduced individually into an open-field test. After weaning, individuals where housed individually and feed intake and body weight were recorded bi-weekly for one month. Data have been partly analyzed, however, the growth, feed intake and additional behavioral elements need to be related to the elements of activity and play behavior recorded in the home pen. This part of the experiment has proven to be extremely time and resource consuming.
In a following experiment, piglets were filmed in a runway where they display locomotor play behavior, involving jumping, running and other persistent and frenetic behaviors. Repeatability of a play marker was investigated at 37, 41, 44, and 48 days of age. Since the animals had never been out of their pen before, the first test was considered as an adjustment period and was not included in the analysis. In the second to the fourth test, joyful brusque movements (jumping, turning and running) where recorded with a camera and number of movements and total time were estimated individually. In addition, body weight was recorded. Body weight was not significantly related to the number or time of joyful movements in any of the three tests. Since dominant pre-weaned piglets generally have higher growth rates than subordinates this may indicate that the joyful movements investigated in this study are relatively unrelated to their social position. Females had higher scores than males. Results indicate that the measurements were litter specific and day dependent. The play marker investigated in this experiment is promising and will be used in following experiments.
In a following experiment, a total of five litters were investigated one week after birth. Litters were video recorded during two hours in the morning to investigate play behaviour in piglets. Teat order was recorded during this period. At the end of the two-hour period, animals were confronted with a novel object in the home pen and their response towards this novel object was recorded on video. In the second part of the experiment, each individual piglet was subjected to a labyrinth test for three consecutive days. The test consisted of a start box followed by three doors that each had three choices to pass to the next box. Only one door could be opened. Learning ability was tested in this experiment and will be related to teat order and play behavior in the home pen and towards the novel object. In the second phase of the experiment, animals were mixed after weaning and group behaviour was recorded on video in the following three days after weaning. The ability to adapt to this novel, stressful environment after mixing will be related to the aforementioned traits. The data are currently being analyzed.
The farm animal of the future is described as ‘robust, adapted and healthy’. Robustness is “the ability to combine a high production potential (growing or reproductive) with resilience to stressors,
allowing for unproblematic expression of a high production potential in a wide variety of environmental conditions”. The expectation of project SelectionForWelfare is to provide further insights into the need for considering behavior and welfare traits in the breeding objective in farm animals. The benefits of this insight will affect breeding companies where the findings of this research can be applied to breeding strategies, to farmers where higher levels of animal welfare are expected to result in higher levels of production, to the livestock industry, where higher levels of animal welfare will improve the image of livestock production, and to the pigs, who will be raised with a higher level of animal welfare.

Contact details: Wendy Rauw, INIA, Crta de la Coruña km 7.5 28040 Madrid, Spain, tel: +34 913473591, email:
Web address:!about/c20r9