Effects of feeding dry or modified wet distillers grains with solubles with or without supplemental calcium oxide on ruminal metabolism and microbial enzymatic activity of beef cattle.

The objectives of this study were to determine the interaction of feeding dry (DDGS) or modified wet (MDGS) distillers grains with solubles (DGS) with or without supplemental CaO on in situ DM and NDF disappearance; ruminal pH, VFA, and methane concentration; and cellulase and xylanase activity. Fistulated steers (n = 8; average initial BW = 540 ± 250 kg) were used in a replicated 4 × 4 Latin square design. Treatments were arranged in a 2 × 2 factorial, and steers were randomly allotted to 1 of 4 dietary treatments: 1) 50% DDGS with 0% CaO, 2) 48.8% DDGS supplemented with 1.2% CaO, 3) 50% MDGS with 0% CaO, or 4) 48.8% MDGS supplemented with 1.2% CaO (DM basis). The remainder of the diet was husklage, dry-rolled corn, and vitamin and mineral supplement. There were no interactions (P ≥ 0.12) of DGS type and CaO addition on any parameters measured. Steers fed DDGS had a 17% increase (P < 0.01) in DMI compared to steers fed MDGS; however, CaO supplementation reduced (P = 0.03) DMI by 12%, regardless of DGS type. As expected, addition of CaO increased the pH of the diet by 1.82 pH units. This caused a time by CaO interaction (P = 0.05) for ruminal pH. Regardless of DGS type, steers supplemented with CaO tended to have increased (P = 0.09) ruminal pH at 1.5 h and had increased (P = 0.03) ruminal pH at 3 h postfeeding; however, ruminal pH did not differ (P ≥ 0.24) for the remainder of the day. There was no difference (P = 0.46) in ruminal cellulase activity when comparing type of DGS fed. However, there was a time by CaO interaction (P < 0.01); cattle fed 1.2% CaO diets had 28% greater ruminal cellulase activity only at 0 h postfeeding when compared to cattle fed 0% CaO. Furthermore, feeding supplemental CaO increased (P = 0.04) acetate to propionate ratio (A:P) regardless of type of DGS fed. Increased initial ruminal pH and cellulase activity from supplemental CaO did not increase (P = 0.48) in situ NDF disappearance. No differences (P ≥ 0.48) in ruminal methane concentration were found when comparing DGS type or supplemental CaO. In conclusion, the type of DGS fed had little effect on ruminal metabolism. Even though CaO increased ruminal pH and cellulase activity at some times postfeeding, it was not enough to affect in situ fiber disappearance.

Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium.

Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively affect immune status and prevent colonization and shedding in Salmonella typhimurium-infected chicks. Using a completely randomized design, 1-d-old commercial broiler chicks (n = 240 chicks; 4 replications/treatment; 5 chicks/replication) were assigned to 1 of 6 dietary treatments differing in concentration of GGMO-AX (0, 1, 2, or 4%) or containing 2% Safmannan or 2% short-chain fructooligosaccharides. Cellulose was used to make diets iso-total dietary fiber. On d 10 posthatch, an equal number of chicks on each diet were inoculated with either phosphate-buffered saline (sham control) or Salmonella typhimurium (1 × 10(8) cfu). All birds were euthanized on d 10 postinoculation (PI) for collection of intestinal contents and select tissues. Body weight gain and feed intake of chicks were greater (P < 0.05) in infected chicks PI for all time periods, except for weight gain on d 0 to 3 PI. Gain:feed was affected (P < 0.05) by diet, with Safmannan-fed chicks having the highest G:F and 1% GGMO-AX-fed chicks having the lowest. The GGMO-AX substrate demonstrated effects similar to a prebiotic substrate as indicated by increased cecal short-chain fatty acid concentrations, decreased cecal pH, and increased populations of Lactobacillus spp. and Bifidobacteria spp. as dietary GGMO-AX concentration increased. Excreta Salmonella typhimurium populations on d 5 and 10 PI, and ileal and cecal Salmonella typhimurium populations, tended to be affected (P < 0.10) by the main effect of diet. Messenger RNA expression of IFN-γ in the cecal tonsils was the only cytokine independently affected by infection and diet (P < 0.01). Chicks fed 2 and 4% GGMO-AX had similar expressions of IFN-γ and IL-1ß, regardless of infection, suggesting that Salmonella typhimurium virulence was suppressed. Dietary supplementation with GGMO-AX resulted in prebiotic-like effects but did not limit Salmonella typhimurium intestinal colonization or shedding, but possibly decreased the virulence of Salmonella typhimurium within the digestive tract.