The proportions of starch, sugar and protein eaten by horses appear to be a factor in the presence of free faecal liquid, research suggests.
Free faecal liquid is characterised by the excretion of faeces in two phases — one solid and one liquid — which may cause dermatitis on the hindlegs. The liquids and solids may be passed together or separately.
The cause of the condition is not known, but results from previous studies indicate that feed ration composition and management factors may play important roles in its occurrence.
Researchers Katrin Lindroth, Jan-Erik Lindberg, Astrid Johansen and Cecilia Müller performed a study in which data on feed rations, feeding practices and management factors were compared between horses with free faecal liquid and those without it.
The researchers had one case and one control horse on each of 50 private farms in Sweden and Norway. The forage on each farm was sampled three times for analysis.
The comparisons showed that, collectively, the horses were reported to be fed similar average amounts of wrapped forage and were subject to similar management practices.
However, the horses with free faecal liquid were fed higher proportions of concentrates in their diet and lower average amounts of straw and lucerne compared to the control horses, who did not discharge free faecal liquid.
“Case horses were reported to be fed twice as much concentrate per 100 kilograms of bodyweight a day as control horses and had a higher daily intake of starch and water-soluble carbohydrates,” the authors reported in the journal Animals.
The horses affected by the condition also tended to have a lower daily intake of digestible crude protein and neutral detergent fibre compared to the control horses.
Overall, these differences were small but are of interest for further studies of factors causing free faecal liquid, the researchers said.
Discussing their work, the researchers noted that most of the case horses were reported to have an ideal body condition score.
A higher proportion of case horses compared to control horses tended to be kept as companion animals. In a previous study, the majority of horses with free faecal liquid (62%) were not ridden.
“It is not possible to draw any conclusions on the cause-and-effect relationship between exercise and the presence of free faecal liquid,” they said. “But as fewer horses with free faecal liquid than control horses were in any training, it is possible that the presence of free faecal liquid is perceived by the horse owner as a hindrance to training.”
Overall, feeding practices and management factors, without factoring in the feed itself, were similar for horses with and without the condition.
“Case and control horses in each horse pair were kept on the same farm and subjected to the same general management and feeding practices, with only minor variations in these variables between case and control horses.”
Turning to the feed itself, the authors noted that, in a previous case study, increasing the number of feedings per day contributed to resolving the condition.
The authors noted that all horses in the study were fed wrapped forage. “There are, however, many other factors that may differ between different forage, such as plant maturity at harvest, harvest number and botanical composition, among others.”
Turning to concentrates, the authors said case horses were fed a higher amount and proportion (per 100kg of body weight) of concentrates compared to control horses.
The difference in the proportion of concentrates in the total feed ration was small (9.7% in the case horses, 9.1% in the control horses) but it influenced the total daily intake of water-soluble carbohydrates and starch, which was higher for case horses compared to control horses.
In conclusion, they said that feed ration composition differed between horses with and without free faecal water, while feeding practices and management factors did not.
“Case horses were reported to be fed more sugar and starch and less neutral detergent fibre and digestible crude protein compared to control horses.
“These variables are of interest for further studies on the causes of free faecal liquid. In several case horses, the signs of free faecal liquid were reported to be eliminated or diminished after changes in the forage batch.
“More detailed studies on forages, such as harvest number, plant maturity at harvest, botanical composition and chemical composition, and their impact on the signs of free faecal liquid are of interest to further investigate.”
Lindroth, Lindberg and Müller are with the Swedish University of Agricultural Sciences; Johansen is with the Norwegian Institute for Bioeconomy Research.
Lindroth, K.M.; Lindberg, J.-E.; Johansen, A.; Müller, C.E. Feeding and Management of Horses with and without Free Faecal Liquid: A Case-Control Study. Animals 2021, 11, 2552. https://doi.org/10.3390/ani11092552