Methodical considerations when estimating nutrient digestibility in horses using the mobile bag technique

Abstract Total collection of faeces is considered the golden standard for estimating apparent total tract digestibility (ATTD) in horses. However, evaluation individual feedstuffs limited and determination nutrient different segments gastrointestinal (GIT) excluded. The rationale performing this study was that mobile bag technique (MBT) can provide information on feedstuffs' degradation, use fistulated animals does additionally regarding degradation GIT. Recommendations using MBT ruminants are well established, but methodical studies have been published with objective to evaluate by comparing ATTD disappearance kinetics hay It hypothesised DM as estimated equal DM. Furthermore, we size has no effect increasing feed surface area (FSA) decreases disappearance. Five caecum cannulated horses were fed a hay-only diet (6.7 kg DM/day) 14 days adaptation followed four consecutive days collection. Three sizes (height × length side, cm; 1.2 × 10 × 2, 3 × 4 × 2, 1 × 6 × 2) three FSAs (10.4, 20.8 41.7 mg/cm2) administrated at each meal (3 meals/day) 1 2 Faeces checked bags every 6th h, time noted together transit (TT) type estimated. Dry matter from fitted profiles, effective degradability (ED) (Dt) determined. results showed DM, organic (OM), NDF ADF be predicted based their bags, ash CP overestimated comparison ATTD. TT 29.2 h, when mean retention 30 h predict ED Dt, it clear underestimated, whereas Dt reflected In conclusion, used estimate OM fibre these nutrients resemble did not affect disappearance, FSA should kept below 20 mg/cm2 higher levels might limit kinetics.