Oat beta-glucan as a dietary supplement for dogs.

The aim of this study was to evaluate the effects of oat beta-glucan supplementation on metabolic, physiological, immunological and nutritional variables in adult dogs. Fourteen dogs were fed a control diet or a diet supplemented with 1% beta-glucan during 71 days. Serum concentrations of glucose, total cholesterol and lipoprotein fractions, as well as plasma concentrations of peptide YY and ghrelin, were determined. In addition, coefficient of total tract apparent macronutrient digestibility (CTTAD), food intake and fecal output, score, and pH were evaluated. For evaluation of immunological variables, serum concentrations of interleukin-4 and interferon gamma were determined on days 0, 57 and 71, which corresponded to blood collection prior to beta-glucan supplementation, and at 7 and 14 days post first and second dose of vaccination (Pneumodog®, Merial, Campinas, Brazil), respectively. Animals fed the supplemented diet showed (P<0.05) lower serum concentrations of total cholesterol and low and very low density lipoproteins, lower coefficients of total tract apparent digestibility of dry matter, organic matter, mineral matter and ether extract, higher fecal output and lower fecal consistency, as well as a tendency (P = 0.07) of decreasing the coefficient of total tract apparent digestibility of crude protein. Moreover, the supplemented diet resulted in lower number of red blood cells, hematocrit percentage and hemoglobin concentration 21 days post-vaccination as well as lower serum concentration of interleukin-4 seven days post-vaccination (P<0.05). It is concluded that oat beta-glucan extract can be used as a dietary supplement for dogs at a dose of 10 g/kg of food, being effective in reducing blood concentrations of total cholesterol, LDL-c and VLDL-c as well as CTTAD of nutrients, demonstrating a potential to be used in the feeding of obese animals. In addition, by reducing the predominance of a Th2 response, oat beta-glucan can positively modulate the vaccine response of animals

Timeline of experimental period and sample collection.

<p>TC: total cholesterol, LDL-c: cholesterol in low density lipoprotein, VLDL-c: cholesterol in very low density lipoprotein, HDL-c: cholesterol in high density lipoprotein, TG: triacylglycerols, INFɣ: interferon ɣ, IL-4: interleukin-4.</p

Chemical composition of the commercial diet supplemented or not with beta-glucan and of the beta-glucan commercial preparation used.

<p>Chemical composition of the commercial diet supplemented or not with beta-glucan and of the beta-glucan commercial preparation used.</p

Interleukin-4 serum concentrations of dogs fed control or supplemented diet with beta-glucan.

<p>Values determined before vaccination (time 0), seven days after the first dose of vaccine (time 7) and 21 days after the first dose of vaccine (time 21). IL-4: interleukin-4. * Means differ by the Friedman test (P<0.05).</p

Oat beta-glucan as a dietary supplement for dogs - Fig 4

<p>(a) Plasma concentrations of PYY (ng/mL) and (b) ghrelin (ng/mL) and (c) glycemia (mg/mL) of dogs fed the control or supplemented diet with beta-glucan. Values determined before feeding (time 0), 60 minutes after feeding (time 60) and 120 minutes after feeding (time 120). No significant differences by the Friedman test (P<0.05).</p

Leukogram (± standard error mean) of dogs fed the control or supplemented diet with beta-glucan evaluated before and after vaccination^a.

<p>Leukogram (± standard error mean) of dogs fed the control or supplemented diet with beta-glucan evaluated before and after vaccination<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0201133#t005fn001" target="_blank">^a</a>.</p

Coefficient of total tract apparent digestibility of nutrients (± standard error mean) of the control or supplemented diet with beta-glucan.

<p>Coefficient of total tract apparent digestibility of nutrients (± standard error mean) of the control or supplemented diet with beta-glucan.</p

Oat beta-glucan as a dietary supplement for dogs - Fig 2

<p>(a) Average body weight variation (g) at 28 and 56 days of the study and (b) Average food intake (g/kg BW) performed between days 35 and 45 of dogs fed the control or supplemented diet with beta-glucan. BW: body weight. No significant differences by the Friedman test (P>0.05).</p

Fecal characteristics of dogs fed the control or supplemented diet with beta-glucan, evaluated between days 24 and 28 of the study.

<p>(a) Fecal output (g/kg BW). (b) Fecal score determined according to the following system [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0201133#pone.0201133.ref020" target="_blank">20</a>]: 1 –hard, dry pellets; small, hard mass; 2 –hard, formed, dry stool; remains firm and soft; 3 –soft, formed, and moist stool; 4 –soft, unformed stool; assumes shape of container; 5 –watery; liquid that can be poured. (c) Fecal pH. BW: body weight. *Means differ by the F test (P<0.05). **Means differ by the Friedman test (P<0.05).</p

Serum lipid fractions of fasted dogs fed the control or supplemented diet with beta-glucan for 28 days.

<p>TC: total cholesterol; TG: triacylglycerols; HDL-c: cholesterol in high density lipoprotein; LDL-c: cholesterol in low density lipoprotein; VLDL-c: cholesterol in very low density lipoprotein.* Means differ by the F test (P<0.05).</p