Effect of a preparation of Saccharomyces cerevisiae on microbial profiles and fermentation patterns in the large intestine of horses fed a high fiber or a high starch diet1

Abstract

Eight horses were allotted into pairs consisting of one cecum- and right ventral colon-fistulated animal and one cecum-fistulated animal. They were fed daily at the same level of intake either a high-fiber (HF) or a high-starch (HS) diet without or with 10 g of a Saccharomyces cerevisiae preparation, in a 4 x 4 Latin square design. The HS diet provided a starch overload (i.e., 3.4 g starch x kg(-1) BW x meal(-1)) while maintaining a high amount of fiber intake (i.e., dietary NDF/starch ratio was 1.0). A 21-d period of adaptation to the treatments occurred before cecal and colonic contents were withdrawn 4 h after the morning meal to count total anaerobic, cellulolytic, and lactic acid-utilizing bacteria, lactobacilli, and streptococci. Lactic acid, volatile fatty acids, ammonia concentrations, and pH were measured on cecal and colonic fluid samples collected hourly during the first 12-h postfeeding. When the HS diet was fed, the concentration of total anaerobic and lactic acid-utilizing bacteria increased (P < 0.001), whereas that of cellulolytic bacteria decreased (P < 0.05) in the cecum. The concentration of lactobacilli and streptococci increased (P < 0.001) in the cecal and colonic contents. These alterations of the microbial profiles were associated with decreases (P < 0.001) of pH, (acetate + butyrate)/propionate ratio and with an increase (P < 0.001) of lactic acid concentration. Supplementing the S. cerevisiae preparation increased (P < 0.01) the concentration of viable yeast cells, averaging 4.3 x 10(6) and 4.5 x 10(4) cfu/mL in the cecal and colonic contents, respectively. Yeast supplementation had almost no effect on microbial counts in the cecum and colon. The supplementation of S. cerevisiae appeared to modify (P < 0.05) pH, concentrations of lactic acid and ammonia, molar percentages of acetate and butyrate with the HS diet and [(acetate + butyrate)/propionate] ratio when the HF diet was fed. The effects of the S. cerevisiae preparation were greater in the cecum than in the colon, which coincided with the abundance of yeast cells. When the digestion of starch in the small intestine was saturated, the effect of the addition of a S. cerevisiae preparation appeared to limit the extent of undesirable changes in the intestinal ecosystem of the horse.

Faecal parameters as biomarkers of the equine hindgut microbial ecosystem under dietary change

“…The hay/barley (B) diet was formulated to provide more than the maximum recommendation of 200 g/100 kg BW of starch in the morning meal (Julliand et al, 2006) and less than the minimal recommendation of 1 kg DM/100 kg BW of hay per day (NRC, 2007). As expected the data showed modifications in the hindgut ecosystem in agreement with those observed by other studies testing concentrate diets (Julliand et al, 2001, Medina et al, 2002de Fombelle et al, 2003) whereby caecal and RV colonic functional bacteria group concentrations (cellulolytics, lactate utilizers) varied, and caecal and colonic microbial activity moved towards an amylolytic activity profile (increase in propionate proportions, valerate and D/L-lactate concentrations and decrease in acetate proportion and VFA ratio [(C2 + C4)/C3]). The impact of the change of diet was marked, despite a high inter-horse variability as seen in the large mean standard errors that was found mainly in lactate concentrations in the caecum and colon.…”

“…The impact of the change of diet was marked, despite a high inter-horse variability as seen in the large mean standard errors that was found mainly in lactate concentrations in the caecum and colon. This confirmed the individual susceptibility, seen in horses fed high-starch diets as previously reported by several authors studying the equine hindgut microbial ecosystem (Julliand et al, 2001;Medina et al, 2002;Dougal et al, 2012 andSchoster et al, 2013;Sadet-Bourgeteau et al, 2014;Costa et al, 2015), and confirmed that some horses are more likely to develop digestive dysbiosis and potential intestinal diseases, such as colic. Using PCA the data showed that the two microbial ecosystems of horses clearly differed with the diet, and thus established that the hindgut microbiota was altered with the B diet.…”

Understanding the equine cecum-colon ecosystem: current knowledge and future perspectives

“…In the cecum, total anaerobes range between 1.85 3 10 7 and 2.65 3 10 9 c.f.u./ml, according to the literature (Kern et al, 1973 andMackie and Wilkins, 1988;Julliand et al, 2001;Medina et al, 2002;de Fombelle et al, 2003).…”

<b>Efeito do tratamento odontológico sobre parâmetros digestivos e metabólicos de equinos</b>

“…Williamson et al (2007) avaliaram os efeitos das proporções de fibra na dieta, concluiram que o aumento da quantidade de fibra está associado com aumento no pH fecal, uma vez que forragens ricas em fibra podem ocasionar um tamponamento nos produtos da fermentação do IG de equinos. Concordando com Medina et al (2002) que afirmaram que baixos níveis de fibra dietética na dietas para cavalos pode acarretar em acidose no intestino grosso.…”