Processing and soaking of sugar beet pulp changes the feeding behavior of horses

Abstract

Sugar beet pulp (SBP) is an interesting alternative to high-starch cereals to provide sufficient energy for athletic horses without compromising their digestive and metabolic health. However, this ingredient has been associated with a risk of esophageal obstruction (EO) in epidemiological studies. The form in which SBP was offered in those studies was not reported, though it could alter ingestion. To support safe feeding of SBP to horses, this study aimed to compare the effect of three products differing by their processing (“SBP shreds”, “IS pellets”: pellets from integral SBP shreds, “GS pellets”: pellets from ground shreds), fed either dry or soaked, on intake and feeding behavior of horses with normal dentition. The hardness and hydration properties of the three products were determined. Each of the six SBP forms was offered [1 kg of dry matter (DM)] on the morning meal] to nine horses with ad libitum access to hay in a change-over design over a period of three consecutive days. On the first two days of each period, SBP meals were given in the horses’ usual boxes. Refusals were collected 90 min after distribution and weighed to determine DM intake. On the third day, feeding behavior of horses was observed during ten minutes in an experimental box. Swelling (P = 0.002) and water retention capacity (P < 0.001) were lower for shreds than for pellets, without difference between IS and GS pellets. GS pellets were softer than IS pellets. No EO were observed along the experimental periods. Horses spent less time masticating (P = 0.005) and more time in prehension (P < 0.001) when receiving shreds, while the time dedicated to mastication (especially away from the feeder, P < 0.001) was longer with the two dry pellets. Higher intake rates were measured with dry IS and GS pellets than dry shreds (P = 0.001). Similar feeding behavior was observed for the two dry pellets, but GS pellets led to a longer drinking duration (P = 0.034), suggesting less intense chewing and saliva production. Soaking did not modify DM intake but altered the feeding behavior. Compared to dry pellets, horses fed soaked SBP pellets increased their chewing intensity (P = 0.005), slowed down their intake rate (P = 0.001), spent less time walking around their box (P = 0.016) and spent more time in front of the feeder in prehension (P < 0.001). The feeding behavior of horses was not different between soaked pellets and shreds. Feeding these voluminous forms of SBP (shreds or soaked products) could be a strategy to reduce intake rate and increase chews/kg DM, providing more benefits to the health and welfare of horses.