Getting to the stomach' of the matter

WARRENSBURG Several 4-H animal science youth gathered to learn about the digestive system of three common farm animals. In this case the animals were horses, cows, and swine. The program covered how each animal processes food and compared the proportion of the stomach and intestines in each of these animals. For example, cows and other ruminants (sheep & goats) have four stomachs: rumen, reticulum, omasum, and abomassum. The rumen uses microorganisms to ferment the fiber rich materials. The stomachs of cattle can be as large as 200 quarts in combined capacity. The cows also have the small intestine, a small cecum, and the large intestine to assist with processing the large amounts of grain, silage, or hay they consume. Why, because they evolved to process grasses and other plant material and the stomachs and intestines allow them to harvest the greatest amount of nutrients from fibrous plants. Even the tongue is designed to reach out, wrap up grass, and rip it up for eating. Source: Cornell Cooperative Extension 4-H Horse Specialist-Jeannie Griffiths and the text, Stockmans Handbook by E. M. Ensminger (1992). The horse on the other hand is referred to in some texts as a pseudo-ruminant or nonruminants. In other words, they eat similarly to cows but they do not ruminate, instead the large intestine is where the horse ferments the food using bacteria. They have only one stomach of about twelve quarts capacity. Horses though have substantially larger capacity in their small and large intestines and they have a large, working cecum, or first segment of the large intestine. Source: UCDavis Book of Horses 1996. Swine, very much like humans, are omnivores. Meaning they eat both plant and animal matter in their natural diets. Their stomach capacity is the smallest and the intestines are drastically smaller than that of either the horse or the cow. Omnivores would of course be able draw some of its nutrients from meat tissue. Source: Stockmans Handbook by E. M. Ensminger (1992). The program involved mathematics by converting the quart capacity into gallons to use various buckets and containers to represent stomach size(s). Yarn of different colors was then used to show proportional relationships of small intestine, cecum, and large intestine in the different species. While the display was not to scale, as typical floor tiles were used to represent a quart of capacity, the dramatic difference in how each of these species is built was self-evident. Would you like to know more about the 4-H Animal Science program or about other programs 4-H programs 4-H has to offer, please call John Bowe at 668-4881 or jfb32@cornell.edu.

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