Common Feeding Practices Pose A Risk to the Welfare of Horses When Kept on Non-Edible Bedding

Abstract

During the evolution of the horse, an extended period of feed intake, spread over the entire 24-h period, determined the horses' behaviour and physiology. Horses will not interrupt their feed intake for more than 4 hours, if they have a choice. The aim of the present study was to investigate in what way restrictive feeding practices (non ad libitum) affect the horses' natural feed intake behaviour. We observed the feed intake behaviour of 104 horses on edible (n = 30) and non-edible bedding (n = 74) on ten different farms. We assessed the duration of the forced nocturnal feed intake interruption of horses housed on shavings when no additional roughage was available. Furthermore, we comparatively examined the feed intake behaviour of horses housed on edible versus non-edible bedding. The daily restrictive feeding of roughage (2 times a day: n = 8; 3 times a day: n = 2), as it is common in individual housing systems, resulted in a nocturnal feed intake interruption of more than 4 hours for the majority (74.32%, 55/74) of the horses on shavings (8:50 ± 1:25 h, median: 8:45 h, minimum: 6:45 h, maximum: 13:23 h). In comparison to horses on straw, horses on shavings paused their feed intake less frequently and at a later latency. Furthermore, they spent less time on consuming the evening meal than horses on straw. Our results of the comparison of the feed-intake behaviour of horses on edible and non-edible bedding show that the horses' ethological feeding needs are not satisfied on non-edible bedding. If the horses accelerate their feed intake (also defined as "rebound effect"), this might indicate that the horses` welfare is compromised. We conclude that in addition to the body condition score, the longest duration of feed intake interruption (usually in the night) is an important welfare indicator of horses that have limited access to roughage.

Keywords: bedding; feed intake pause; feeding practices; horse behaviour; horse welfare; individual housing system; roughage; welfare indicator.

Figure 1

Total time for finishing the evening meal of horses on straw in comparison to horses on shavings, which finished their evening meal within the observation period (79.69%; n = 51 out of 64 horses; median: 325 min of n = 17 horses on straw; median: 307 min of n = 34 horses on shavings, p = 0.04).

Figure 2

Duration of the nocturnal feed intake interruption of horses on shavings, which had finished their evening meal within the observation period (74.32%; n = 55 horses on shavings out of 74 horses on shaving in total). Green box: period without food supply which is still appropriate in terms of welfare; red line: tolerable maximum duration of feed intake interruptions at 240 min (4 hours) according to the German welfare standard [55]).

Figure 3

Frequency of feed intake pauses during the evening meal of horses on straw compared to horses on shavings (n = 55 horses; median: 4.0 of n = 25 horses on straw; median: 3.0 of n = 30 horses on shavings, p = 0.01)

Figure 4

Duration of feed intake pause during the evening meal of horses on straw compared to horses on shavings (feed of hay or a mix of hay and straw to n = 55 horses; median: 15 min of n = 25 horses on straw; median: 7 min of n = 30 horses on shavings, n.s. with p = 0.36)