Digestion, fecal, and blood variables associated with extensive large colon resection in the horse.

The research evaluates how certain nutritional variables differ in horses before and after extensive large colon resection. The results showed that while these surgeries do affect digestion factors and increase fecal matter and water loss, horses can regain lost body weight and show no overt physical changes post-surgery when fed a suitable diet.

Study Design and Procedures

• The research involved 9 horses split into two groups. Group 1 consisted of 3 horses that underwent a sham operation (a placebo procedure), while Group 2 comprised 6 horses that had extensive large colon resection surgery.
• The study monitored nutritional changes in these animals at four different intervals – before the surgeries, and 3 weeks, 3 months, and 6 months after the operations took place.
• The researchers used feed and fecal analyses to assess the digestion of various substances, including dry matter, organic matter, crude protein, and several minerals. Metabolic and fecal variables such as fecal water and metabolic crude protein were also considered.
• A complete blood count and a standard series of biochemical tests were performed on each horse to monitor blood variables and signs of physical affliction.

Key Findings

• The study found that large colon resection decreased the true digestion of dietary crude protein and cellulose. It also lessened the apparent digestion of phosphorus.
• Despite the reduced digestion rates, the horses showed increased fecal metabolic matter and water loss. Specifically, total fecal output rose 45%, while total fecal water went up by 55%.
• Although phosphorus digestion was compromised in horses that underwent colon resection, no adverse effects of this were discernible in blood variables or during physical examination.

Conclusions and Implications

• While extensive large colon resection can hinder certain aspects of digestion and increase fecal matter and water excretion, the negative effects of the surgery can be mitigated through a proper diet. For instance, horses on an alfalfa pellet diet, which meets higher-than-average nutritional requirements, were able to regain lost body weight post-surgery.
• Despite the elevated excretion of water, no notable physical changes were detected in these horses. However, the study suggests providing these animals with abundant water access, as their daily consumption might be about 2 gallons more than that of a normal horse.