Counts of ruminal bacteria collected by nasal tube or ruminal fistula in Somali sheep

GRILLI, D.; PAEZ, S.; EGEA, V.; DEGARBO, S.; LAUSI, O.; GONZÁLEZ, J.; SOSA ESCUDERO, M.; ARENAS, N.

BIOCELL

Año: 2008

0327-9545

Studies of ruminal microbial ecosystem traditionally require the use of animals with surgical fistulae. Limitations of this model are the cost of fistula surgery, need of special care after surgery and animal welfare (an important issue in animal investigation). An alternative to the conventional fistula technique is collecting ruminal bacteria using a nasal tube. The aim of study was to compare the counts of cellulolytic (CB) and total bacteria (TB) collected by nasal tube and ruminal fistula. Samples were collected from one fistulated Somali sheep fed with alfalfa hay. The ruminal fluid was obtained 18 h after feeding, three times each fifteen days. The samples were drawn with a nasal tube (length 1250 mm, inner diameter 4 mm) and immediately thereafter through the ruminal fistula. TB counts were performed by the roll tube method. Most-probable-number procedure using basal medium with cellulose (filter paper) was used to estimate numbers of CB. TB and CB numbers were lower in the samples obtained through nasal tube that in those obtained through fistula. CB are usually attached to plant fiber. Samples taken through nasal tube contained smaller quantities of fiber. Therefore, the number of bacteria is lower in the samples obtained by this technique. In conclusion, samples of rumen fluid for determining TB and CB should not be obtained using the technique of nasal tube.