August 2013
For What It's Worth

After it got sick, the animal never did do right.

 

Some of you with livestock may have occasionally experienced certain animals within your herd that became severely infested with gastrointestinal parasites and never seemed to fully recover. While you feel every effort was made to identify the problem and treat accordingly, endurance and severity of parasite infestation may have damaged certain parts of the digestive system, causing inefficient nutrient absorption and processing, and causing lackluster growth and development. Such situations hold potential for slow growth rates when compared to other animals the same age, ongoing health problems and relevant expense and possibly diminished economic returns or even mortality.

 There is a logical explanation for all this, which can be better understood by gaining knowledge of a ruminant’s digestive system. The following information applies to ruminants of all sizes. A ruminant is a mammal that digests plant-based food by initially softening it within the animal’s first compartment of the stomach principally through bacterial actions, then regurgitates semi-digested mass (cud) and chews it again. The process of rechewing the cud to further break down plant matter and stimulate digestion is called ruminating. There are about 150 species of ruminants including cattle, goats, sheep, giraffes, yaks, deer, camels, llamas and antelope.

 

 The rumination process is defined as regurgitation, rechewing and reswallowing of rumen ingesta. During times of resting, animals frequently repeat this process with forages and feeds. Animals may spend up to eight hours per day ruminating. The more often the process is repeated, the further forages and feeds are broken down allowing nutrients and micronutrients to become more readily accessible.

 The internal parts of the digestive system include the mouth, esophagus, four stomach chambers, small intestine, cecum, large intestine and accessory glands. Each part has a function which is briefly described below:

 – Mouth – Chew and swallow

 – Esophagus – Passage from mouth to stomach

 – Four stomach chambers:

 – Rumen – Micro-organisms (bacteria, protozoa and enzymes) break down fiber and feed

 – Reticulum – Smaller overflow from rumen

 – Omasum – Grinds feed & removes some water

 – Abomasum – True stomach, breaks down feed proteins

 – Small Intestine – Two parts further breaking down nutrients and absorbing compounds

 – Cecum – Further digestion by micro-organisms

 – Large Intestine – Two parts (colon and rectum) further digestion by micro-organisms and removes water

 – Accessory Glands – Salivary glands, liver and pancreas contributing saliva, bile and enzymes that aid with digestion

 To summarize the digestive process let’s review the following occurrences:

 – Digestion in ruminant animals accomplished via microbial breakdown of feed and forages in rumen and reticulum

 – Enzymatic activity takes place in abomasum and small intestine

 – Microbial breakdown in cecum and large intestine

 – Simple compounds derived from digestion of carbohydrates, proteins and fats absorbed mainly in fore stomach and small intestine

 Now that you know more about the function and process within each organ of the digestive system, you can better understand how the four stomach chambers, small and large intestine, and cecum are affected during infestation of gastrointestinal parasites, specifically stomach worms and coccidian. To better comprehend all this helps relate how health and productivity are compromised as the result of extreme and lengthy worm and coccidian infestation.

Barberpole Worm Infestation

What occurs:

 – Worm borrows into internal layer of stomach

 – Ingests red blood cells

 – Leaves scar tissue which does not facilitate ideal processing or absorption of nutrients

Resulting In:

– Lowered growth rates, vigor and reproductive performance

– More vulnerable to illness and mortality

– Potential reduction in profits

Coccidia

What occurs:

– Pathogens ingested via grazing or dirty water and feed vessels

– Oocysts penetrate cells lining the intestines

– Inflammation & destruction of cell lining

– Inner layer of intestine may reveal hemorrhaging or ulceration of intestinal wall

Resulting In:

– Lowered growth rates, vigor and reproductive performance

– More vulnerable to illness and mortality

– Potential reduction in profits

By now you see the potential for damage to the digestive system of ruminants resulting from lengthy and severe infestation of gastrointestinal parasites. You can probably better understand why young, developing animals are more susceptible than fully developed, adult animals. Damage to any parts via internal parasites negatively affects nutrient processing and absorption, and development, which has more significant consequences.

In the future when you suspect internal parasite problems with you animals, try to make quick and thorough diagnosis and appropriate treatment. Take action when you first notice the following: an animal appearing lethargic, head and tail are hanging down, and they have diarrhea, rough coats and poor body-condition. Learn to use: observation, experiences, fecal-egg counts, FAMCHA and a congenial vet-client relationship to ensure accurate and efficient treatment for animals exhibiting symptoms of gastrointestinal parasite infestation. This strategy will decrease the likelihood for substandard development, diminished health and expensive health treatment, and potential for mortality and/or economic losses.

Resources:

– Coccidiosis in Goats and Prevention, UNP-109

– Digestive Anatomy in Ruminants: http://www.vivo.colostate.edu/hbooks/pathphys/digestion/herbivores/rumen_anat.html

– Digestive System of Goats, UNP-60

– Haemonchus contortus(Barber Pole Worm) Infestation in Goats, UNP-78

– Ruminant, Wikipedia: http://en.wikipedia.org/wiki/Ruminant

Robert Spencer is an Urban Regional Extension Specialist with the Alabama Cooperative Extension System.