Effects of Malt Extract on Nutritional and Functional Aspects in Healthy Adult Dogs

Abstract

The co-product malt extract has prebiotic constituents, such as sugar and beta-glucans. Therefore, the aim of this study was to evaluate how the malt extract inclusion in healthy dogs’ diet effects digestibility, fecal microbiota, fermentative metabolites, and immunity. Twelve healthy two-year-old dogs were used, randomly divided into two groups according to food consumed: control treatment (CT), without the addition of malt extract, and malt treatment (MT), with 1.0% malt extract inclusion (natural matter) during two experimental periods. The results obtained were analyzed by the computer software Statistical Analysis System (SAS, version 9.4). Values of p < 0.05 were considered significant. No differences were observed in the apparent digestibility of nutrients and fermentation metabolites. However, a reduction was observed for metabolizable energy (p = 0.0004) in the malt diet. The predominant phylum for both treatments was Firmicutes (p < 0.0001), the mean of which was higher in MT dogs. The bacterial groups belonging to the cluster Clostridium XIVa and genus Faecalibacterium, which are responsible for producing short-chain fatty acids, were higher after MT consumption (p < 0.0001). On the other hand, MT dogs presented a reduction in the genus Bifidobacterium (p < 0.0001), which is responsible for producing lactic acid. There was also an increase in lymphocyte proliferation index (p = 0.0071) and rate (p = 0.0025) and in CD4+:CD8+ lymphocyte ratio (p = 0.0098) after MT consumption. Thus, the inclusion of 1.0% of malt extract in the diet had a prebiotic effect in healthy adult dogs.