Monday, November 12, 2012

Science Week 13: Hoofs, Horns, Antlers...and special stomachs

We did continue along, even though I didn't get the updates posted. It's been a hectic autumn season around here with a few extra incidents needing attention compared to normal. So, here are the updates thru November, and I will get the December weeks posted in a decent time-frame. With the holidays, we won't be 'on-track' for a week by week plan, but we'll make it up again come January. I hope for those following along this doesn't cause too much of an issue.

Although sometimes called antelope, pronghorn are not closely related to the animals of African plains. In fact they are so different from other hoofed animals that they are the only members of the family Antelocapridae. Their head ornaments set them apart from deer and elk whose branched, solid antlers are shed each year, and from goats and cattle whose hollow horns are made from hair and are not shed. Pronghorn have branched, hollow, hairlike horns that are shed annually. They are the only animal with this combination. Read more from U.S. Fish & Wildlife Service

pronghorn buck
photo via San Diego Zoo

Fleet-footed pronghorns are among the speediest animals in North America. They can run at more than 53 miles (86 kilometers) an hour, leaving pursuing coyotes and bobcats in the dust. Pronghorns are also great distance runners that can travel for miles at half that speed. Read more from National Geographic

Mountain Goat Pictures
Mountain Goat

Dalls Sheep Photos
Dall's Sheep

Dall's Sheep Pictures
Dall's Sheep

Desert Bighorn Sheep Photos
Desert Bighorn Sheep

Peninsular Bighorn Sheep Picture
Peninsular Bighorn Sheep

Bighorn Sheep Pictures, Jasper National Park
Bighorn Sheep

American Bison

white-tail deer

Caribou, Muncho Lake Provincial Park, British Columbia Photo

Mule deer

Photo Bull Moose
Bull Moose

Pictures of Elk

Horns and Antlers:
The terms horns and antlers are often used interchangeably, but in reality, they refer to quite different structures. Antlers are a pair of bony, branched structures that protrude from the frontals of the skull of animals and are shed annually; horns are also paired and protrude from the frontals, but they are permanent, unbranched, and made up of a bony core and a keratinized sheath. See more information at Animal Diversity Web
Horns and Antlers from Natural Bridge Wildlife Ranch
Deer Antlers from the Izaak Walton League of America
ZooPax from WhooZoo

Special Stomachs:

The ruminant (digastric) stomach
  Rumen:     "The fermentation vat"  The largest compartment that is key to volatile fatty acid absorption.  Recticulum:  "The honeycomb" It sorts particles by size, this allows for better breakdown of food.  Omasum:  "The folded structure"  It traps particles within the folds, where the particles are squeezed to remove water prior to delivery to the abomasum.  Abomasum:  "The true stomach"  This is where the final breakdown of digestion takes place.

Ruminant digestion.
Cows and other ruminants have a very different digestive system than humans do which work very differently in order to digest the foods they eat. The stomachs that they have all serve different purposes in order to break down these foods properly. Humans eat so many types of foods that our bodies cannot always break down them correctly. This can lead to fatty build ups amongst other issues. This is why we often turn to things like Medifast diets in order to stay in shape. The ruminants use their different stomachs in a series events so that different protozoans and bacteria can properly breakdown the hard to digest foods. Some of us could use four stomachs to help do this but we have different options like a Medifast coupon out there that can help us to produce the proper bacteria we need to maintain our diets. Each phase of the ruminants' digestion helps to provide them with valuable nutritional substances like protein.
The first chamber is the large rumen (or paunch). The next two are the reticulum and the omasum (psalterium or manyplies). These first three chambers are believed to be derived from the esophagus. The last chamber is the abomasum (or reed), which corresponds to the stomach of other mammals.
The combined four-chambered stomach is big. In the domestic ox (Bos taurus) the whole stomach occupies nearly three-quarters of the abdominal cavity. In medium sized cattle, the rumen by itself can hold between 25 to 75 gallons. The rumen grows large in early life after the changeover from a milk diet.
Ruminants eat fast and store large quantities of grass or foliage in the rumen, where it softens. Many species of minute protozoans and bacteria live without free oxygen in the rumen. These little animals and bacteria digest the cellulose in the plant material, thereby releasing the contents of the plant cells for digestion by the cow. Large amounts of saliva get secreted into the rumen to further the digestion.
The action of the various microbes produces various substances, including fatty acids which are absorbed through the rumen wall. In addition, any protein is converted into fatty acids and ammonia; the ammonia and other simple nitrogen-containing substances are used by the micro-organisms for their own cell-protein synthesis.
After the plant material is processed in the rumen, it is later regurgitated. This material is now called cud, and the ruminant chews it again. The additional chewing breaks down the cellulose content, which is difficult to digest, even more. The regurgitation and chewing of the cud is called rumination.
The chewed cud goes directly to the other chambers of the stomach (the reticulum, omasum, and abomasum, in that order). Additional digestion, with the aid of various essential microorganisms, continues in these other chambers. For example, in the omasum, some fatty acids and 60-70 percent of the water are absorbed. In the abomasum gastric juice containing hydrochloric acid is secreted, as in an ordinary mammalian stomach, futher digesting the food. Also, those micro-organisms that used the ammonia and other nitrogen substances from protein in the rumen, actually get digested by the ruminant in the abomasum and small intestine, thereby providing the cow with protein.  via Crazy for Cows
Sites and Notes:
SmithLife Science has an incredible collection of links and YouTubes for mammals of all kinds. Definitely a bookmark worthy site!
Goat lapbook at HomeschoolShare
The Yearling book lapbook, HomeschoolShare
Deer lapbook, from The Adventure Life blog
Fact Sheets from God Did Creations

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