In-vivo and In-sacco method for testing dry matter digestibility of Norwegian cold-blooded horses

Abstract

Two types of feeds with different fiber sources were investigated in five caecum cannulated Norwegian cold-blooded horses. This objectives of the experiment was to increase fermentable fiber (Sugar beet pulp) into horse diet thereby reduce starch intake of total ratio by partly substituting hay. At the same time, we aimed to evaluate the In-sacco mobile bag technique and apparent dry matter (DM) digestibility of hay and Sugar beet pulp (SBP) by comparing it to Invivo total feces collection method. In-sacco mobile bag technique examined the apparent hindgut digestibility of hay and SBP in 45 mobile bags respectively and each bag contained 0.5 mg feed samples. In-vivo total feces collection method assessed the DM apparent total tract digestibility (ATTD) of In-vivo diet (Hay +SBP). Two trials were carried out simultaneously and feces were collected in stablemaids (harnesses). Following previous 14 days of adaptation period, feces and mobile bags were collected every 6 hours over four days. In-vivo ATTD of Hay and SBP diet were calculated with observed apparent DM digestibility of each feed stuff based on In-sacco mobile bag technique in various feed ratio and mean retention time (MRT). There were significant apparent DM digestibility differences between SBP and hay and between SBP and In-vivo diet ATTD (Hay +SBP). Apparent DM digestibility of both hay and SBP increased along with bags retention time in hindgut. Calculated value showed that In-vivo diet (Hay + SBP) ATTD of DM increases along with the addition of SBP proportion and increases of MRT.