“The cattle on a thousand hills and all the forest beasts are mine”.
All the creatures of the field are Jehovah’s. He hath created them and He sustains them. Interesting it is indeed, to study his marvelous handiwork and observe specific adaptions of the various specimens in the animal kingdom.
Of all the animals He created, the ruminants have been most useful to man. They have provided food, clothing, and transportation for all people thru-out the ages. In Leviticus 11:3 we read, “Whatsoever parteth the hoof, and is cloven-footed and cheweth the cud, among the beasts, that shall ye eat.” Now by ruminants are meant animals which chew their cud as the cow, sheep, goat, yak, llama, water buffalo, deer, and the camel. Most of the ruminants fulfill the levitical requirements for clean animals – the yak and the water buffalo being related to the cow, while the llama to the sheep. However, the camel (as is mentioned in the Bible) is an exception because its hoof is not divided and hence considered unclean.
Why are these animals called ruminants? All of them possess a peculiar enlargement at the posterior end of the esophagus (the part of the digestive tract connected to the stomach) which is called a rumen. Frequently, this is merely considered a storage chamber, but it is much more than that, for here the food is thoroughly wetted and mixed with saliva. In addition millions of microscopic animals called protozoa and bacteria are constantly at work breaking down the otherwise indigestible cellulose (cell walls) and lignin (woody fibers).
Undoubtedly, most of you are familiar with the ordinary diet of these animals. As the grass, hay, corn, or other types of grain and fodder as much too coarse from immediate digestion, they must pass thru a process of predigestion in the rumen which is particularly adapted for this task. As the food passes down the digestive tract, it stimulates the wall of the lower esophagus to enlarge causing the slit-like opening of the rumen to expand; thus allowing the food to enter. Here the food often remains from twelve to twenty-four hours, as it requires a considerable amount of time for these microscopic creatures to break down the cellulose and lignin.
The average cow secretes approximately eleven gallons of saliva daily, which is used in digesting the contents of the rumen. In the process of breaking down plant materials, saliva plays an extremely important role. While the bacteria are breaking down lignin and cellulose they produce acids which would soon kill themselves, if it were not for the neutralizing effect of the saliva which tends to maintain proper growing conditions for the microbes. About 10% of the contents of the rumen consists of these beneficial bacteria and protozoa. E. G. Hastings has stated, “The transformation of food into microbes is so great that some have been led to say that the ruminant lives not on the material ingested but upon the mass of micro-organisms that have been formed from that material.”
Perhaps, some of you readers have the impression that cud is recently swallowed food. However, it has undergone a lengthy process of pre-digestion. Small quantities are then regurgitated by a reverse process, so that it once again enters the mouth where it is further ground between the molar teeth, which is in the process commonly termed “chewing the cud.” Again it passes down the esophagus but this time without irritation because of the softness of the bolus (cud) and consequently; the rumen is not opened and the food passes directly into the stomach for further digestion. Thus, members of this group can eat large quantities very rapidly for very little time is taken for mastication as it can be temporarily stored in this pouch – the rumen.
However, the finely ground commercial foods or liquids fail to stimulate the esophageal wall; and thus the rumen opening remains closed and the food enters the stomach without special processing. It is now a well known fact that ruminates do now thrive on concentrates. Recent experiments performed at the University of California, Division of Animal Husbandry, show that finely ground alfalfa results in decrease or failure of cud chewing, bloating reduction in food consumption, and a deprived appetite which is manifested in wood chewing. The “control cattle” were fed regular alfalfa hay and showed none of these symptoms.
In mature animals the rumen when filled is estimated to make up one fifth of the total weight of the animal. The capacity of the rumen of a 1000 pound cow is approximately 25 gallons.
It might be of interest to note that although Leviticus 11:5, 6 mentions the hare and the coney (rock badger) as cud chewers (which from all appearances is true due to the peculiar movement of the jaws while chewing), never-the-less, they cannot be classified as true ruminants (cud-chewers) as they lack the rumen and have not the power of regurgitation.
The ruminants have two definite advantages, they can eat coarser foods because of their special process of pre-digestion, and they can go without food for a longer period of time.
What animal offers a more realistic picture of contentment than a ruminant lying in the shade of a tree leisurely “chewing his cud”?