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New perspectives for metagenomic analysis: Rumen sampling via esophageal tube using a manual vacuum pump.

F. E. Miccoli

Events

06-23-2020

Abstract:

281
New perspectives for metagenomic analysis: Rumen sampling via esophageal tube using a manual vacuum pump.
F. E. Miccoli*1,2, S. Ferreyra1, S. Maresca3, S. L�pez-Valiente3, P. Sueldo3, N. Juliano2, R. A. Palladino1,4, J. L. Danel�n2, R. I. Galarza3. 1Faculta de Ciencias Agrarias - UNLZ Buenos Aires, Argentina, 2Departamento de Produccion Animal, UBA Buenos Aires, Argentina, 3INTA Cuenca del Salado Buenos Aires, Argentina, 4Consejo de investigaciones Cient�ficas, CONICET Buenos Aires, Argentina.

Even though rumen fistulation is the main technique for rumen sampling, similar microbiome can be found between cannula and the intraesophageal tube samples. The main constrains of the tube technique are related to saliva contamination, comparable solid and liquid fractions and the site of extraction which affects the microbial community structure. With the aim to collect adequate samples for metagenomic analysis, a combined device + technique (Rumen Sampler MG) is described after validated with beef heifers (172.3 � 16.17 kg BW) and dairy cows (554.66 � 25.19 kg BW). Device: A manual pump (Professional Hand-held vacuum pump - Eurotech, Germany) is connected to a PVC flexible tube (40mm wide) through a short PVC tube (20 � 80 mm) to ensure the ideal vacuum. The intraesophageal tube is twice wider than other devices and has no holes to avoid obstructions with solid material and is beveled edge for a more rapid flux. Its length depends on animal size (the length to reach the rumen was previously checked using an endoscopic camera). Technique: Intravenous application of neuroleptic dosed at 0.25mL/100 kg BW (Acepromacina 10mg/mL, Acedan — Holliday, Argentina) and wait 3—5 min for the animal to relax and stay still. A rigid PVC tube (6x20cm) is located over the tongue to insert the flexible tube and past the epiglottis. Once inside the rumen, slight vacuum pressure is applied (7—10 bar) to avoid damages on the epithelium. After the sample is obtained, rumen contents are deposited in a 250mL beaker for visual examination of saliva contamination and pH measurement (Hanna HI98128 pHep 5 Waterproof), in addition to evaluate the liquid-solid ratio and total volume. In case the sample quality is not appropriate for metagenomic analysis, the sampling can be immediately repeated due to neuroleptic effect lasts between 15 and 17 min and the procedure takes approximately 8 min. The �Rumen sampler MG� combines a simple and rapid procedure and a more adequate device for obtaining higher quality samples for microbiome studies, in addition of taking care of animal welfare.

Keywords: rumen microbiome, esophageal tube, manual pump.