Fistulated animals today serve an invaluable role for their own species. Using fistulation and cannulation techniques, we as researchers have the unique opportunity to prolong the cow’s life and longevity in a dairy herd. In the past we were able to test the feed that was fed to a cow in macroscopic experiments; attaining samples from the feed fed, and that which was excreted, but now we are able to test the digestibility and absorption of different feed commodities in the rumen through the miraculous porthole in the cow’s digestive system, the fistula. This middle point sampling location is vital due to the many enzymatic and digestion activities which occur in the rumen, affecting the animal’s utilization of feed. The nutritional needs of a dairy cow do not primarily consist of alfalfa or other forages, but the forage (inclusive of all different hays) and concentrate (all grains including corn, barley, cottonseed, etc.) ratio is dependent on how much milk she is producing. In the Holstein breed, the cows that are black and white in color, produce milk for approximately three-hundred days, during which time she can produce up to 100 to 140lbs in any one day. For animals producing this much milk, they will need to eat more than those who produce only 30-60lbs per day. Imagine a child that continuously plays outside for four hours a day, biking, running, and playing with his/her friends, and another who only plays outside for one hour, who will come to the dinner table the hungriest? Of course the one who exerts more energy. Similarly, cows which produce more will exert more energy and will consume more feed. Like the children, we want our cows to eat as healthy as possible, but we are incapable of asking them how they feel so we must perform tests to ensure their nutritional requirements are being met. Such tests require samplings from the rumen; if the fistula was not present we would have to look at how the feed affects the cow via changes in her milk production, reproductiveness, and her general body conditioning. Even by looking at all these external cues, we would still not know which one of the foodstuffs in the diet lead to the change, was it the corn, hay, barley? To find out we can easily and painlessly perform experiments using the fistulated cows. An example of such an experiment, includes inserting different foodstuffs into a small semi-permeable bags and placing these bags altogether into the rumen via the fistula. After twenty-four hours the bags are taken out and the digestibility and absorption can be ascertained.
The above experiment is just one in many, and is an example of how the fistulated cows are able to help the members of their own species. She is a partner in our attempt to maintaining the healthiest animals possible. She is not harmed by these studies, and as the tracheostomy tubes enable people breathe, ruminal cannulas and the experimental results attained from such research help dairy producers feed the correct blend of commodities to maximize milk production while ensuring their cow’s health and longevity.
