Fig 4. The effect of exogenous lactobacilli addition on the viable number of Group D Gram-positive cocci (GPC) in equine fecal cell suspensions.

Grain types included minimally processed, finely ground (2 mm screen) corn, oats and wheat at 1.6% w/v starch concentration. Treatments included initial (open bars; 0 h), control (black bars; substrate only), and the addition of L. acidophilus (green bars), L. buchneri (blue bars), L. reuteri (red bars) and Mixed (purple bars; all 3 at equal concentrations) at 10⁷ final concentration live or dead (autoclaved; corn only). Samples were taken after 24 h of incubation (37°C) for bacterial enumeration. GPC were enumerated on bile esculin azide agar (BD). The plates were incubated aerobically (37°C, 3 d). Plates with 30 < x < 300 colonies were counted. Black colonies on bile esculin azide agar were counted as GPC. Hatched lines separate individual statistical comparisons. Means lacking a common letter are different between treatments within substrate (P < 0.05); Corn: treatment, P < 0.0001; Oats: treatment, P < 0.0001; Wheat: treatment, P < 0.0001; Pooled SEM Corn: treatment = 0.1190; Oats: treatment = 0.0859; Wheat: treatment = 0.0091 (log₁₀ transformed).