Effects of a blend of chestnut and quebracho tannins on gut health and performance of broiler chickens.

Antimicrobial restrictions prompted the search for cost and biologically effective alternatives to replace antimicrobial growth promoters (AGPs) in food-producing animals. In addition, the efficacy of this alternatives needs to be contrasted in field/commercial trials under different challenge conditions. However only a few studies describing the impact of tannins or others AGP-alternatives in commercial poultry production conditions are actually available. The aim of the present work is to study how the inclusion of a blend of chestnut and quebracho tannins can affect broiler productive performance and health under commercial conditions. Three experiments with different approaches were conducted: (1) a trial comparing the effects of both additives (tannins vs AGP) on different commercial farms at the same time; (2) the follow-up of one farm during an entire productive year; and (3) an experimental trial using a C. perfringens challenge model in broiler chickens. Although productive results from field trials were similar among treatments, evaluations of gut health indicators showed improvements in the tannins treated flocks. Frequency and severity of intestinal gross lesions were reduced in jejunum (42% vs 23%; p<0.05-1.37 vs. 0.73; p<0.01, respectively) and ileum (25% vs. 10%; p<0.0.5-1.05 vs. 0.58; p<0.01) in tannins treated birds. Results from 16S studies, show that cecal microbiota diversity was not differentially affected by AGPs or tannins, but changes in the relative abundance of certain taxa were described, including Lactobacillus and Bifidobacterium groups. Results from experimental C. perfringens necrotic enteritis showed that tannins treated birds had reduced incidence of gross lesions in jejunum (43.75 vs. 74.19%; p<0.01) and ileum (18.75% vs. 45.16%; p<0.05) compared with control. These results suggest that AGPs can be replaced by tannins feed additives, and contribute in the implementation of antimicrobial-free programs in broilers without affecting health or performance.

Impact of Chestnut and Quebracho Tannins on Rumen Microbiota of Bovines.

The use of phytogenic dietary additives is being evaluated as a means to improve animal productivity. The effect of tannins seems to be the influence not only directly on the digestive process through binding of dietary proteins but also indirectly over their effects on gastrointestinal microbiota. High-throughput sequencing of 16S rRNA gene was used to analyze the impact of dietary supplementation with a blend of chestnut and quebracho tannins on the rumen microbiota of Holstein steers. Bacterial richness was lower in tannins treated animals, while the overall population structure of rumen microbiota was not significantly disturbed by tannins. The ratio of the phyla Firmicutes and Bacteroidetes, a parameter associated with energy harvesting function, was increased in tannins supplemented animals, essentially due to the selective growth of Ruminococcaceae over members of genus Prevotella. Fibrolytic, amylolytic, and ureolytic bacterial communities in the rumen were altered by tannins, while methanogenic archaea were reduced. Furthermore, ruminal pH was significantly higher in animals supplemented with tannins than in the control group, while urease activity exhibited the opposite pattern. Further work is necessary to assess the relation between tannins impact on rumen microbiota and alteration of rumen fermentation parameters associated with bovine performance.

Comparison between two methods to record occlusal contacts in habitual maximal intercuspation

This research evaluated two techniques to record the occlusal contacts in habitual maximal intercuspation obtained in models mounted in semi adjustable articulator and in the mouth using an eight-micrometer carbon paper and sensors (T-Scan II). It was selected a sample of twenty five people, male and female, ages between twenty and twenty five years old with natural dentition. The collected data were visually and statistically evaluated by means of the Spearman coefficient. The results showed that the carbon paper as material used for the occlusal contact records enabled to determine exactly the quantity and its locations in the occlusal surface. However, it did not provide the information on the sequence, time and intensity on how these occur. The T-Scan system enabled to determine the quantity, the sequence and the exact time that they occur, however the system did not determine the exact location of the contacts over the teeth occlusal surface. It was observed that in both methods, the quantity of the occlusal contacts recorded in the mouth was higher than the ones obtained in the articulator and that the sensor thickness did not interfere in the reproduction of the quantity of dental contacts in comparison to the carbon paper.