Influence of diets containing barley and corn grain (steam-flaked or cracked), with or without Enterococcus faecium probiotic on digestibility, fecal pH, blood glucose, and pathologic problems of adult horses

The objective of this study was to investigate the effect of two processing methods of barley and corn grains (steam-flaking or cracking) and the addition of a probiotic containing Enterococcus faecium (10 g/d to provide 2.5 × 1011 colony-forming unit) to diet on nutrients digestibility, fecal pH, blood glucose, and pathologic problems of horses. In this experiment, 12 adult Kurdish horses with an average weight of 416± 43 kg were used in a replicated 4×4 Latin Square experiment with a 2×2 factorial design during four periods of 28 days, including 21 days for dietary adaptation and seven days for sampling. Experimental diets (60:40 forage to concentrate ratio) were: 1) Cracked grains based diet without probiotic, 2) Cracked grains based diet with 10 g/d probiotics, 3) Steam-flaked grains based diet without probiotic, 4) Steam-flaked grains based diet with 10 g/d probiotics. Results showed that mean fecal pH was 6.57 in different treatments and was not affected by the type of grain processing, probiotic supplementation, and their interaction (P>0.05). Also, digestibility of dry matter, organic matter, NDF, and ADF, as well as blood glucose, lameness, and colitis incidence were not affected by two types of cereal processing including cracking or steam-flaking, the addition of probiotic, and their interaction. Overall, our results showed that replacing steam-flaked corn for cracked corn and supplementing 10 g per day enterococcus faecium probiotic did not affect digestibility, fecal pH, and blood glucose. However, further research is recommended to investigate the effects of higher enterococcus faecium probiotic doses in high grain diets.