Salivation Salivation occurs when feed is in the mouth and - ANSI - 3543E
View Full Document
Salivation: Salivation occurs when feed is in the mouth and when it is not. There are many similarities in salivation between a cow and a pig. This is when secretion and mixing of saliva with food occurs. The parotid, submaxillary, and sublingual glands produce saliva. Both cows and pigs use saliva for moistening and lubricating food to help with chewing and swallowing. Another similarity is that it stimulates taste nerves. Also the washing action of saliva cleanses the mouth and prevents decay of leftover food particles. But the amount of saliva produced varies with species, diet, and health. In cows and other ruminants, saliva production is abundant and relatively continuous, although greater quantities are produced when eating and ruminating than while resting. Saliva produces N, P, and Na, which are utilized by rumen microorganisms and not by nonruminant species. Another difference between cows and pigs is that the ruminant relies on saliva for its buffering action. Saliva contains bicarbonates that buffer rumen acids, especially the volatile fatty acids. Another contrast is that the pig is the only farm mammal in which any amount of the enzyme ptyalin (amylase) is secreted by saliva. It is weak and only starts to break down the starch in food. Swallowing or deglutition: Swallowing is the reflex of passing food, water, or anything else from the mouth to the stomach via esophagus. This process is similar in both cows and
This preview has intentionally blurred sections. Sign up to view the full version.
View Full                                                         Document
ANSI 3543 E Submitted via email 3/30/13 Writing Assignment #4 pigs. The swallowing reflex is under neural control and is triggered by the presence of a material in the back of the mouth. Food is moved to the stomach by muscle contractions. The cardiac valve is at the end of the esophagus and it prevents food from coming back into the esophagus. The difference is that cows regurgitate so food is not being prevented from coming back into the esophagus. The Stomach’s Role in Digestion: After passing through the esophagus, the feed travels to the animal’s stomach. The stomach is used for mechanical and chemical digestion of feed but it also functions in storing food. The stomach is the major difference between a cow (ruminant) and a pig (nonruminant). A cow’s stomach is composed of the following four compartments: rumen, reticulum, omasum, and abomasum. In contrast, a pig has a simple monogastric stomach. The main function of the cow’s complex stomach is to allow the animal to use roughages (cellulose) as a source of energy. Microorganisms that are present in the first three stomachs ferment material and provide nutrients otherwise unavailable to the animal. The first of the cow’s four stomach compartments is the rumen. The rumen is the site of anaerobic bacterial fermentation. The bacteria in the rumen digest carbohydrates and other plant materials in the mixed feed and produce volatile fatty acids as an excretory byproduct. These volatile fatty acids are absorbed through the rumen wall and give about 50 percent of the energy required for the ruminant. The next compartment is the reticulum. It also functions as a site of microbial action. The reticulum is a pacemaker of rumen contractions, mixing and moving contents through the
This is the end of the preview. Sign up to                                     access the rest of the document.
TERM
Courtney Pritchett ANSI 3543E 1. Define nutrition in your own words.  The process by
Assignment #1.docx