Rumen cannulation of sheep by Hecker method - a case study

Abstract

to surgery, and preparation of the left flank region for surgery. Immediately prior to the surgery parenteral analgesic injection was administered and left para-vertebral nerve block was performed. The rumen wall was exteriorized through a laparotomy incision and a metal clamp was applied. Simple interrupted sutures were placed using nylon through the skin, rumen wall and the clamp. After 7-9 days the exteriorized rumen wall sloughed off leaving a fistula. A tight rubber cannula was inserted through the fistula and the cannula was closed with a ring and stopper. The antibiotic and analgesic were repeated post-operatively for three days. The cannulated animals were used for a one-year research project and the animals were clinically normal throughout the project. Evaluation of the digestible components of the diets of grazing animals has been emphasized by various nutritionists, physiologists and pathologists (Phillipson and Innes, 1939). As the quality and the quantity of the ruminal fluid obtained via a stomach tube are inadequate, an alternative method for collecting the ruminal fluid was preferred (Harmon and Richards, 1997). Rumen cannulation is a minimally invasive technique which allows access to the rumen for in vitro and in vivo studies (Sedeek and Suliman, 2007). The first successful ruminal fistulation was performed by Colin in 1886 in an ox, but the fistula was not closed by mechanical means (Phillipson and Innes, 1939). The same procedure was followed by Schalk and Amadon in 1928 in cattle and an attempt was made to close the fistula using a block of wood (Phillipson and Innes, 1939). Over the years modifications and new evolutions of these methods have taken place (Phillipson and Innes, 1939). Open fistulae have been used in ruminants for digestibility trials for a long period of time, but it has shown some disadvantages, including unsightly appearance and unsatisfactory carrying out of physiological work after fistulation (Grovum, 1988). Open ruminal fistulae also allow loss of water, electrolytes, nitrogen and organic matter, which is another main drawback, leading to loss of weight and body condition of the animals (Grovum, 1988;