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Zebeli Q.,Institute of Animal Nutrition | Zebeli Q.,Research Cluster Animal Gut Health | Metzler-Zebeli B.U.,Research Cluster Animal Gut Health | Ametaj B.N.,University of Alberta
Journal of Dairy Science | Year: 2012

This study examined the extent by which changes in the concentrate level and neutral detergent fiber (NDF) content in the diet as well as the severity of acidotic insult, measured as the duration time of rumen pH below 6.0 and daily mean rumen pH, and the concentration of endotoxin in the rumen fluid are involved in the development of inflammatory conditions in cattle. A meta-analytical approach accounting for inter- and intraexperimental variation was used to generate prediction models, and data from recent studies were used to parameterize these models. A total of 10 recently conducted experiments with 43 different dietary treatments fulfilled the criteria for inclusion in this study. Diets of all of the experiments included in this meta-analysis were based on rapidly degradable grain sources, such as barley and wheat, and the findings of this study apply only to these kinds of diets. Data indicated that greater levels of concentrate in the diet were associated with increased concentrations of rumen endotoxin (R2=0.27), plasma haptoglobin (R2=0.19), and serum amyloid A (SAA) level (R2=0.46). Similar correlations, but in opposite directions, were observed between dietary NDF content and rumen endotoxin (R2=0.39) and plasma SAA concentrations (R2=0.22). The meta-analysis revealed that the relationships between those variables were not linear. Additionally, the breakpoint model fitted to the data of rumen endotoxin, plasma haptoglobin, and SAA indicated the presence of a threshold level of dietary concentrate and NDF, above which those responses became linear to increasing amounts of concentrate or decreasing contents of NDF in the diet. Also, feeding cattle more than 44.1% concentrate or less than 39.2% NDF in the diet was associated with a linear increase in the risk of systemic inflammation. Low daily mean rumen pH (R2=0.38) and duration of rumen pH <6.0 (R2=0.59) were associated with increased concentrations of endotoxin in the rumen fluid; although those events were not always associated with systemic inflammation. Accordingly, only 15 to 21% of the overall variation in the responses of SAA was explained by variables of rumen pH, whereas the concentrate level in the diet accounted for 46% of this variation. In conclusion, data from this study indicated the presence of thresholds of dietary concentrate and NDF levels in the diets based on rapidly fermentable grains beyond which the risk of systemic inflammation in cattle increases linearly. © 2012 American Dairy Science Association. Source


Mann E.,Institute of Milk Hygiene | Mann E.,Research Cluster Animal Gut Health | Schmitz-Esser S.,Institute of Milk Hygiene | Schmitz-Esser S.,Research Cluster Animal Gut Health | And 9 more authors.
PLoS ONE | Year: 2014

Dietary composition largely influences pig's gastrointestinal microbiota and represents a useful prophylactic tool against enteric disturbances in young pigs. Despite the importance for host-microbe interactions and bacterial colonization, dietary responses of the mucosa-associated bacterial communities are less well investigated. In the present study, we characterized the mucosa-associated bacterial communities at the Pars non-glandularis of the stomach, ileum and colon, and identified shifts in these communities in response to different dietary calcium-phosphorus (Ca-P) contents (100% versus 190% of the Ca and P requirements) in combination with two basal diets (wheat-barley- or corn-based) in weaned pigs. Pyrosequencing of 16S rRNA genes from 93 mucosal samples yielded 447,849 sequences, clustering into 997 operational taxonomic units (OTUs) at 97% similarity level. OTUs were assigned to 198 genera belonging to 14 different phyla. Correlation-based networks revealed strong interactions among OTUs at the various gastrointestinal sites. Our data describe a previously not reported high diversity and species richness at the Pars non-glandularis of the stomach in weaned pigs. Moreover, high versus adequate Ca-P content significantly promoted Lactobacillus by 14.9% units (1.4 fold change) at the gastric Pars nonglandularis (P = 0.035). Discriminant analysis revealed dynamic changes in OTU composition in response to dietary cereals and Ca-P contents at all gastrointestinal sites which were less distinguishable at higher taxonomic levels. Overall, this study revealed a distinct mucosa-associated bacterial community at the different gut sites, and a strong effect of high Ca-P diets on the gastric community, thereby markedly expanding our comprehension on mucosa-associated microbiota and their diet-related dynamics in weaned pigs. © 2014 Mann et al. Source


Klevenhusen F.,Institute of Animal Nutrition | Klevenhusen F.,Research Cluster Animal Gut Health | Muro-Reyes A.,Autonomous University of Zacatecas | Khiaosa-ard R.,Institute of Animal Nutrition | And 5 more authors.
Animal Feed Science and Technology | Year: 2012

This study examined the role of supplementation of several bioactive compounds (BC) and the chemical composition of the diet used as substrate for in vitro incubations, on in vitro ruminal fermentation profile and nutrient degradation. A meta-analytical approach was used to weigh the sample size used in each experiment, and account for the random effect of each as well as unequal variance among studies. A total of 20 recently conducted experiments with 354 treatments, each including one control (i.e., no BC supplementation), fulfilled the criteria for inclusion. Doses of BC supplementation varied from 0.03 to 500mg/g dry matter (DM) of incubated diet. Contents of crude protein (CP) and neutral detergent fibre (NDF) of the incubated diets (DM basis) ranged from 139 to 189 g/kg and 160 to 420 g/kg, respectively. Results indicate that supplementation of BC linearly decreased (137.4 versus 116.5mmol/L; P<0.05) concentration of total volatile fatty acids (VFA) and proportion of acetate (P<0.05). Also, the concentration of ammonia in the in vitro rumen fluid was lower with BC supplementation (22.9 versus 15.6mg/dL; P<0.05). Analysis by backward elimination correlation analysis revealed that inclusion of the chemical composition of the incubated diet into the model with BC supplementation improved the accuracy of estimation of responses of fermentation variables. Thus, higher NDF and CP contents of the substrate and higher BC dosage were associated with lower concentrations of total VFA (r 2=0.54), whereas both lower CP contents of the substrate and BC supplementation lowered the concentration of ammonia (r 2=0.32). This analysis showed negative associations between BC supplementation and in vitro disappearance of DM and NDF, and positive correlations with dietary NDF content. In contrast, higher BC inclusion and lowering NDF content in the diet was accompanied with decreased in vitro CH 4 formation (r 2=0.21). Results indicate that BC supplementation and chemical composition of the incubated diet are determining factors which impact responses of in vitro ruminal fermentation and degradation. © 2012 Elsevier B.V. Source

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