A two-stage rumen cannulation technique in sheep

This experimental study was carried out to describe and evaluate a modified two-stage technique of rumen cannulation in sheep. Ten healthy, castrated, Makoyee sheep with no previous history of gastrointestinal dysfunction were chosen. The surgical technique was performed in two stages. In the first, a 5-cm vertical incision was made in the mid paralumbar fossa. The incision was continued through the subcutaneous. Then the muscular layers of the abdominal wall were divided in the grid technique. The dorsolateral portion of the dorsal sac of rumen was anchored to the skin by application of four interrupted horizontal mattress suture at 4 points circumferentially using No. I silk. In the second, the exposed rumenal wall was incised longitudinally at the mid part of the stay sutures. A rubber-sheep cannula was inserted into the opening and then fixed with an external elastic washer. To augment the cannula stability, the inner flange was also reinforced with a tough rubber washer. All the sheep had normal behavior and appetite during the experiment. In the follow up period no local inflammation, infection, hemorrhage, tissue flap necrosis, wound dehiscence and suture abscess encountered in the surgical site. Neither evidences of anorexia, toxemia, septicemia and peritonitis were detected. No sign of intra peritoneal infection was observed on inspection of carcasses. The sheep did not lose weight significantly and the cannulas remained permanent fixed in position in 9 cases. This modified ruminal cannulation technique could be considered as a useful alternative with less failure and no more adverse consequences. Furthermore, the technique might be recommended to veterinary scientists who deal with experimental studies on sheep nutrition and husbandry.