Effects of diet and feeding on postprandial serum gastrin and insulin concentrations in adult horses

Abstract

Summary Gastrin is the only hormone known to stimulate secretion of hydrochloric acid. It also has trophic effects on specific parts of the mucosa of the gastrointestinal tract. Using radioimmunoassay techniques, postprandial serum gastrin and insulin concentrations were measured in six adult horses to establish effects of different diets on gastrin concentrations. Insulin concentrations were measured to provide support to the patterns of gastrin secretion because patterns of insulin secretion were already known. The horses were fed coastal bermuda hay, or twice daily 5 kg of a complete pelleted ration, 5 kg of commercial sweet feed or 5 kg of the sweet feed together with hay. There was little change in serum gastrin or insulin concentrations after feeding hay alone. Rations containing more readily available nutrients (pellets, sweet feed) produced significant increases in postprandial serum gastrin and insulin concentrations. Gastrin concentrations also varied according to the duration of feeding each diet, but this was not seen with insulin. These results indicated that gastrin secretion, and therefore possibly gastric acid secretion, were markedly influenced by dietary composition and duration of feeding a diet. There appeared to be some adaptation of the stomach (gastrin secretion) to changes in diet, but this was not accompanied by indications of adaptation in the endocrine pancreas (insulin secretion).

The influence of low versus high fibre haylage diets in combination with training or pasture rest on equine gastric ulceration syndrome (EGUS)

“…It is believed that salivary bicarbonate and the buffering effect of roughage (structural fibre) is responsible for an increased pH in cases of constant hay feeding, compared to withholding feed (Smyth et al 1998). Constant access to good quality hay or alfalfa also helps to raise the pH in the stomach (Murray and Eichorn 1996b).…”

Assessment of Gastric Ulceration and Gastrin Response in Horses with History of Crib-Biting

“…Gastric acid secretion is stimulated by gastrin, a peptide hormone secreted by G cells located in the glandular portion of the stomach in response to gastric distension, dietary protein, and increased luminal pH [15]. Gastrin concentration in horses increases following feeding [16,17,18], with greater and more prolonged gastrin secretion occurring in response to pelleted and sweet feed diets than roughage [19]. Concentrate feeding is also associated with an increased risk of CB behavior [20,21], with increase in CB frequency observed in periods following concentrate feeding [22,23].…”

Gastric Ulceration, Appetite and Feeding Practices in Standardbred Racehorses in the Czech Republic

“…Racehorses are usually fed a high concentration diet which is associated with gastric ulceration (Hammond et al 1986). The horses fed with a concentrated feed show lower gastric pH (Murray and Schusser 1992; Murray 1994b) and higher serum gastrin concentration (Smyth et al 1988). We did not obtain exact data on feed composition, gastric pH or gastrin concentration in our study.…”