A Life Worth Living: Assessing Positive Welfare In Cows, Sheep, And Goats
As the concern for animal welfare grows, there’s an increased interest in evaluating not just the absence of suffering, but the presence of positive welfare. Positive well-being is difficult to define, but we can think of it as including being healthy and comfortable, with opportunity to express natural behaviors, and free of persistent pain and fear. But there’s not necessarily agreement about what that means in practice. For example, one could argue that access to pasture is positive, because it’s not strictly necessary for health or survival. Another view would be to consider access to pasture only neutral, because grazing is a natural behavior.
The authors of this article examined the existing literature for ways to measure positive well-being in ruminants – including cows, sheep, and goats. Specifically, they were interested in measures that are based on the animal (rather than management or productivity) and that could be taken on the farm rather than in a lab.
The first area of well-being they looked at was nutrition. It turns out that lack of food choice can induce a stress response in some animals, and many animals will eat different foods at different times of day if given the choice. Synchrony – performing the same behavior at the same time – is associated with positive well-being, because it’s an indicator of social cohesion. Feeding at the same time also benefits less dominant animals because it reduces competition for food. While food choice can be difficult to measure on farms, feed synchronization is easily measured.
Positive welfare related to the animal’s environment is typically related to how the environment allows them to express choice and preference, as well as experience comfort. One measure of comfort is the amount of time spent lying down, which increases with more room and deeper bedding. However, since time spent lying down can also increase with sickness or lameness, this measure isn’t sufficient alone. It can also be difficult to measure based on the observation time needed, and the need to carefully choose the sampling period.
While health or vigor seem like obvious ways to measure positive well-being, in practice, the measures available are limited. One problem is that longevity is not a useful measure, for two reasons: we don’t necessarily observe natural longevity in captivity, and because a long life in poor conditions is of course not an indication of positive welfare. Some measures that could be developed further include vigor – which can be measured by the time it takes to attempt behaviors such as standing and nursing after birth – and coat or fleece quality.
On the other hand, there are a range of behavior-related measures of well-being including play, bonding, foraging, and interactions between parents and their offspring. Play is an unnecessary behavior that is not expressed under stress, although it can also be an expression of relief when conditions improve. Nursing is a necessary behavior but also one that is performed in response to disturbances, showing that it has a value related to comfort as well as nutrition.
Another behavior associated with well-being is allogrooming, or grooming and licking between pairs, particularly around the face and neck. In goats and sheep, this is normally performed by the mother on her lamb or kid, but it occurs in cows into adulthood. The recipient may show a number of signs of increased well-being including lowered heart rate, weight gain, or increased milk production. As we’ve seen before, however, this is a measure that needs to be used with care as it can also be associated with boredom, or can be expressed as a way to relieve tension.
Exploration of a new environment is self-rewarding, and can indicate that the environment is sufficiently complex and stimulating. The animal’s motivation to explore can be measured by presenting a new object in a controlled setting. Animals that are under-stimulated will be more motivated to explore than used to a rich environment.
Finally, there are numerous ways to measure a positive mental state, which can mean calmness, curiosity, or pleasure at the anticipation of a reward. Animals, like humans, respond to ambiguous stimuli with optimism or pessimism depending on their mood, but specific tests of this behavior can be difficult in practice as they require previous training.
Another possible approach is one called qualitative assessment of animal behavior, which describes mental state on two axes: arousal (calm to active) and mood (indifferent to curious). This method can be used on the farm, and is shown to be consistent between different observers and between observations for the same observer, so it can be considered a reliable method.
Body position can be an indicator of mood, but is dependent on the species. For example, rapid ear movements are associated with negative states in sheep, but positive ones in cows. More study would be required to use this as an indicator and to understand the reliability. Likewise, tail wagging is considered positive in cows and sheep, while the tail up is positive in goats.
There are also promising measures which would require automation to be practically useful. For example, measuring the percentage of the white of the eye visible is an indication of calm or satisfaction, but is currently time-intensive to measure by hand. Vocalizations can be used as well, but there hasn’t been enough study done on which vocalizations relate to positive states. This would also be more feasible if there were automated tools to collect and characterize the sounds.
Overall, there are a wealth of methods now available to understand if animals are simply not suffering, or if they are living what could be called a “good life”. However, these techniques are largely concentrated around environment, behavior, and mental state, with a lack of assessments related to health and nutrition. In order to create an effective positive welfare protocol, more work is needed to understand the reliability of these methods. In addition, while many are theoretically feasible on farms, technical advances are required to make them more practical, such as proximity trackers, and automated analysis of video and audio. Furthermore, satisfying positive welfare would require a significant move away from intensive agriculture — something animal advocates have been pushing for for decades.