Selective Feeding in Horse herds

Why do horses need to be fed at the same time?

Selective feeding – the practice of feeding certain horses while others in the herd are present –

can trigger significant stress reactions and disrupt both the physiological balance and the social

stability of the group. This is why you need to feed them all at once or completely separate them for feeding.

A white mare nose deep in hay with a herd buddy.

Effects of Selective Feeding in the Presence of Other Horses on Behavior and Stress Levels

Horses are strongly social herd animals whose well-being depends heavily

on harmony, predictability, and equitable resource distribution. When this balance is disturbed by

preferential feeding of individual animals, the organism responds through the activation of stress

systems, which manifest in both behavior and neurobiology.

Neurobiological Effects of Selective Feeding

The horse’s brain is highly sensitive to social inequality and resource insecurity. When some

horses receive feed while others are left out, the nervous system of the excluded animals

interprets this as a potential threat. This perception activates several stress mechanisms: -

Increase in cortisol: The affected horse experiences “resource stress.” The perception of being

denied access to food triggers secretion of the stress hormone cortisol.

- Amygdala activation: The brain’s emotional alarm center perceives the situation as

dangerous, leading to increased vigilance or a flight response.

- Dominance of the sympathetic nervous system: Heart rate and muscle tension rise, while

digestion and relaxation processes are inhibited – a classic “fight-or-flight” state.

- Reduced oxytocin: Feelings of social exclusion lower production of the bonding hormone

oxytocin, reducing trust and calmness. Even the horses that receive feed may experience stress

due to competition or the need to guard their food.

Social Dimension: Resource Distribution and Group Dynamics

Within a herd, feeding plays not only a nutritional but also a social role. Horses are adapted to

simultaneous, cooperative grazing. When this harmony is disrupted through selective feeding,

tension within the group can quickly arise. Possible consequences include:

- Aggressive behavior (biting, kicking, chasing) between horses,

- Stress and insecurity in lower-ranking or excluded animals,

- Withdrawal, frustration, or learned helplessness when exclusion occurs repeatedly,

- Reduced social cohesion and overall herd instability. From an ethological perspective,

selective feeding represents a social stressor that can undermine the sense of safety and the

hierarchy within the group.

Conclusion

Feeding individual horses in the presence of others should be avoided from a behavioral and

psychological standpoint. This practice acts as a significant stressor for the excluded horses,

leading to increased cortisol levels, heightened amygdala activity, and reduced levels of calming

hormones such as oxytocin. Over time, this can cause anxiety, restlessness, and social tension

within the herd. Horses, by contrast, thrive under simultaneous, fair, and predictable feeding

routines that align with their natural group behavior. Providing enough feeding spaces,

maintaining consistent feeding times, and avoiding preferential treatment promote calmness,

trust, and hormonal balance. These measures help maintain both physiological stability and

social harmony within the herd.