PSXVI-1 The effects of two equine feed supplements on gastrointestinal health as reflected in fecal pH, fecal microbial profiles and digestibility

• Published in: Journal of animal science Vol. 96; no. suppl_3; p. 251
• Main Authors: Johnson, A, Rossow, H
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 07.12.2018
• Subjects: Abstracts; fecal pH; markers
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/sky404.549

Abstract The aims of this study were to investigate the effects of two equine feed digestive aid supplements on hindgut health (HGH) as reflected in fecal pH, fecal microbial profiles and digestibility and to compare and validate DM digestibility measurements through the use of internal and external markers such as chromium oxide (CR),Lignin (Lig), indigestible ADF (iADF), indigestible NDF (iNDF) and indigestible lignin (iLig). Nine mature Quarter horses (6 geldings, 3 mares) were used in a cross over design with three feeding periods of 17 d (51 d total) and using 3 treatments: control, no feed additive (Con), Smartpak (SP), or Platinum Performance (PP). Within the 17 d period, horses were offered orchard grass hay, sweet cob grain, the assigned treatment daily and 4 CR cookies to deliver 8/g/d of CR for the last 7 d of each period. Total feces were collected from 15 to 17 d of the trial. Feed and fecal samples were dried, ground and sent to ANALAB (Fulton, IL) for nutrient analysis. Duplicate samples of feed and feces were placed into ruminally cannulated cows for in situ determination of iADF, iNDF and iLig to estimate digestibility. Estimated CR FO and DM digestibilities were evaluated using the RMSPE, CCC and NSE methods. The best marker was iNDF with the smallest RMSPE (8%), largest CCC (0.55) and an acceptable NSE value (0.17). This study is in agreement with previous studies that iNDF is the best internal marker to estimate apparent digestibility in horses. Treatments PP and SP had no effect on fecal pH or DM digestibility. Since there were large differences in the individual responses of horses to treatments, more subjects may be needed or a lower gut acidosis may need to be induced to detect responses to PP and SP.