Bovine Rumen: Difference between revisions
No edit summary |
|||
| Line 39: | Line 39: | ||
===Nutrition=== | ===Nutrition=== | ||
When a bovine eats, billions of bacteria, protozoa, yeast, and molds in the rumen help the animal to be able to eat and digest the great amount of grasses (protozoa and bacteria doing most of the work). They all live in a symbiotic manner with the cow, helping to breakdown difficult substances while living in a suitable niche. The microbes can aid in the digestion many foods such as hay, grass, grain, corn, and even urea. When microbes breakdown and digest plant fiber they produce volatile fatty acids which are then absorbed into the rumen, supplying about 60 to 80% of the cow’s energy. The microbes also produce essential amino acids from the proteins in which the cow consumes (Hall). | When a bovine eats, billions of bacteria, protozoa, yeast, and molds in the rumen help the animal to be able to eat and digest the great amount of grasses (protozoa and bacteria doing most of the work). They all live in a symbiotic manner with the cow, helping to breakdown difficult substances while living in a suitable niche. The microbes can aid in the digestion many foods such as hay, grass, grain, corn, and even urea. When microbes breakdown and digest plant fiber they produce volatile fatty acids which are then absorbed into the rumen, supplying about 60 to 80% of the cow’s energy. The microbes also produce essential amino acids from the proteins in which the cow consumes (Hall). | ||
A proper nutrition is important for bovine heath, especially for domestic cows raised for their milk or beef. Inadequate or unbalanced nutrition can lead to many problems including poor growth, increased cases of illness, and lower rates of reproduction. As previously described, bovine nutrition consists mostly of grasses, weeds and plants, but proper nutrition is not that simple. For example, the domestic cow requires a strict diet to remain healthy and maintain a well-functioning rumen. Some rules that producers must abide by are that diets should contain no wore than 5% fat, fiber should be kept between 30 to 70% of daily intake, and cattle that graze in fields with high concentration of legumes must be supplied with ionophores or poloxolene. All these rules were created so to promote a health rumen (Hall). | A proper nutrition is important for bovine heath, especially for domestic cows raised for their milk or beef. Inadequate or unbalanced nutrition can lead to many problems including poor growth, increased cases of illness, and lower rates of reproduction. As previously described, bovine nutrition consists mostly of grasses, weeds and plants, but proper nutrition is not that simple. For example, the domestic cow requires a strict diet to remain healthy and maintain a well-functioning rumen. Some rules that producers must abide by are that diets should contain no wore than 5% fat, fiber should be kept between 30 to 70% of daily intake, and cattle that graze in fields with high concentration of legumes must be supplied with ionophores or poloxolene. All these rules were created so to promote a health rumen (Hall). | ||
Revision as of 00:38, 29 August 2008
Biorealm Niche: Bovine Rumen
Description of Niche
What is Bovine Rumen (and other parts of bovine stomach)?
Bovines (of bovinae subfamily) are unique in a way that they have four stomach compartments to digest their food. Those compartments are rumen, reticulum, omasum, and abomasum. Of these, rumen is the largest compartment, and it can hold as much as 50 gallons of food and other ingested substances. The most important part about rumen is that it contains huge amount of different microbes, including bacteria, fungi, and protozoa. Reticulum, or "honeycomb," is the part responsible for rumination (or cud chewing) and trapping hard, indigestible substances like rocks, nails, or wires that may be ingested by accident while the bovine is grazing. If the reticulum gets punctured or injured from metal or other sharp objects, it can lead to traumatic reticuloperitonitis, or "hardware disease," and it is very important that this does not happen (5 Wilson). Omasum, or "many-piles," is a leaf-like folds shaped compartment that acts as a gateway to the abomasum. Its main role is to send back large substances back to rumen and reticulum while allowing smaller, well-broken down substances to pass through into abomasum. Then, abomasum, also called "true stomach," is very similar to human stomach, as it is responsible for producing acids and enzymes to break down proteins, and it sends the chyme to small intestine (2 Hall).
In the rumen, there are billions of microbes living in a symbiotic manner. There are about 25 to 50 billion bacteria and 200 to 500 thousand protozoa. These microbes help the bovine to breakdown ingested food, while the bovine provides them with shelter and nutrients. Without them, bovines would have tough time digesting plant fibers and starches and producing useful fatty acids. Bovines can eat a wide range of feeds because they have many different kinds of microbes to help them digest. They eat and ruminate/regurgitate the incompletely chewed bolus back into the mouth so they can chew again. This process helps the microbes to have access to more finely chewed food in order to make microbial digestion easier. They can even eat urea because the microbes can use non-protein nitrogen to create amino acids. The microbes also produce other essential substances like vitamins B and C (2 Hall).
Although rumen-microbial system is a powerful factory for food consumption, it is also sensitive to sudden changes in feed-types. For example, if the bovine is accustomed to feeding on high levels of fiber and low levels of starch, then the rumen is equipped with more fiber-digesting microbes. Then, if the food content is suddenly changed to high starch and low fiber, the bovine would not be able to properly digest the feeds. This may lead to sudden decrease in pH, as the starch just sits in the rumen and ferments, and can cause harmful illness such as acidosis. Therefore, it is crucial to keep the nutrition of the bovines constant, especially for the domestic cows and oxen (2 Hall).
The bovines are also responsible for producing large amounts of methane gas, due to many methanogens like the strains of Methanobrevibacter, Methanomicrobium, Methanobacterium, and Methanosarcina living in the rumen. About 6% of what they eat gets lost as methane gas. This has been brought up in issues about global warming, and the effects of bovine methane in the environment are currently being researched (4 Whitford).
Physical Conditions
Inside of the bovine rumen tends to have pH at around 6.5 to 7.2. Malnutrition, such as over-feeding of starch, can decrease pH level drastically and can be very harmful for the bovines. 20-35 gallons of saliva produced per day provides sodium bicarbonate to keep the pH consistent for the microbes to grow. Most of water in saliva is not wasted, but recycled in the body (2 Hall).
Since it is inside of bovine body cavity, the oxygen level is low or absent in the rumen, so it is an anaerobic condition. The absorption of the carbohydrates and volatile fatty acids is done by the epithelium of the rumen, which allows the ruminal juices to seep in between the cells. To increase the surface area for absorption, the ruminal mucosa contains numerous conical papillas (5 Wilson).
The temperature of a healthy bovine tends to range from 37.8 °C to 40.0 °C, the core organs being around the high end. Temperature of the bovine depends mainly on body part and time of the day. For body part differential, the closer to the core, the higher the temperature becomes. Thus, temperature of the rumen is around 40.0 °C. Moreover, rumen contents tend to ferment at 40.0 °C, so this works as a central self-heating system. Temperature of the skin can be as much as 10 to 20 °C lower than the core temperature. Furthermore, time of the day makes difference in bovine body temperature. The temperature is usually cooler in the morning after resting and warmer in the night after long day of muscular activity. Recent studies have shown that hormonal interactions after giving birth can affect female cow’s body temperature as well. The range of healthy body temperature is fairly narrow, and thus it is very important to maintain that range in order to carry out normal metabolic and microbial functions (1 Chen).
These conditions show that the microbes in the rumen are obligate anaerobic mesophiles that only grow in non-extreme conditions.
Environment (Bovine Habitat)
The environment in which different bovine live can make a huge difference in the rumen function and physiology. The most well known example of a bovine for Americans is the domestic cow. Since these animals are domesticated, they are found in agriculture areas all over the world. Some are kept in tightly packed farms and others are able to graze across grasslands. These grasslands are not fertilized to produce any source of food for the cattle. Cattle that graze typically eat grass, stems, and other plant material (Dewey). A cow’s rumen has a pretty standard pH of 5.8 to 6.2 and a temperature of 100 to 108°F. The pH is dependent on the number of the microbes found in the rumen which is determined by the type and amount of food being consumed from the environment. The acidic rumen along with the microbes living there help ferment and breakdown the cellulose in the grass. The environment also has an impact on the size of the rumen, which in a domestic cow is 60 to 80 liters. Since cattle eat a lot of grass, a large rumen is needed to accommodate a large volume of food (Woodley).
Another specific example of a bovine is the wild yak. Wild yak live in areas of uplands such as hills, plains, and mountainous regions, all of which lack trees. They are generally found in the mountains regions of Southwest China, as well as Tibetan Plateau (Massicot). Yaks tend to intake less food than other bovines, giving the yak a much smaller rumen. The smaller rumen gives the yak a lower outflow rate of rumen fluid than typical cattle. This rate is just 3.1 to 3.5 liters per hour. This outflow rate is dependent on many factors of the environment, some of these factors being the solidity of the food, air temperature, and size of the food particles. Yaks also produce more volitile fatty acids than other ruminates. These fatty acids can affect the fermenting capacity inside the rumen. This higher production of volitile fatty acids is directly related to the roughage on which yak feed (Ruijun).
Another type of bovine is the water buffalo, also known as the wild Asian buffalo. These buffalo are found where water is easily available, usually in low-lying grasslands, woodlands, or forests adjacent to a body of water (Massicot). Water buffalo feed on a greater range of food than cattle. They tend to eat dry weeds along with aquatic plants, even diving up to 2 meters under the floodwaters just to graze. Just as the yak does, water buffalo make a higher amount of volatile fatty acids and produces it more quickly than does cattle. This is also due to the roughage available in the environment (The Water Buffalo). As compared to cattle, water buffalo have a very similar pH, yet there is a higher population of bacteria inside the rumen. More specifically, water buffalo rumen contained more bacteria and fungus, but lower amounts of protozoa. Since water buffalo have a more diverse feed, they use a higher diversity of organisms in the rumen to digest the food (Wanapat).
The environment is a huge determinant on the physical properties of the rumen among different bovine species. The amount of nutrition a species consumes can determine the size of the rumen. The types of food available in the environment can change the pH as well as the microbes living in the rumen. Some species oven have different rate of outflow coming out of the rumen. All these differences are determined by the environment in which the specific bovine lives.
Nutrition
When a bovine eats, billions of bacteria, protozoa, yeast, and molds in the rumen help the animal to be able to eat and digest the great amount of grasses (protozoa and bacteria doing most of the work). They all live in a symbiotic manner with the cow, helping to breakdown difficult substances while living in a suitable niche. The microbes can aid in the digestion many foods such as hay, grass, grain, corn, and even urea. When microbes breakdown and digest plant fiber they produce volatile fatty acids which are then absorbed into the rumen, supplying about 60 to 80% of the cow’s energy. The microbes also produce essential amino acids from the proteins in which the cow consumes (Hall).
A proper nutrition is important for bovine heath, especially for domestic cows raised for their milk or beef. Inadequate or unbalanced nutrition can lead to many problems including poor growth, increased cases of illness, and lower rates of reproduction. As previously described, bovine nutrition consists mostly of grasses, weeds and plants, but proper nutrition is not that simple. For example, the domestic cow requires a strict diet to remain healthy and maintain a well-functioning rumen. Some rules that producers must abide by are that diets should contain no wore than 5% fat, fiber should be kept between 30 to 70% of daily intake, and cattle that graze in fields with high concentration of legumes must be supplied with ionophores or poloxolene. All these rules were created so to promote a health rumen (Hall).
Nutrition can even be manipulated to manage milk composition. By maximizing the function of the rumen through feeding, milk component percentages and production are also optimized. A producer of milk cows can increase the feed intake of his cattle and cause an increase in milk production. Producers can also manage other factors so to manipulate the protein and fat percentages of the milk. For example, by decreasing the amount of fiber or by increasing the nonfiber carbohydrates, milk fat is decrease and protein is increased. When fiber is rationed, rumen fermentation causes an increase in propionic acid, causing and decrease in the percentage of milk fat. Also, by decreasing the crude proteins intake, a producer can cause a decrease in milk protein. By adjusting the nutrition of the cow, rumen function can me manipulated so to increase or decrease the percentage of milk fat and protein (Looper).
Who lives there?
Which microbes are present?
You may refer to organisms by genus or by genus and species, depending upon how detailed the your information might be. If there is already a microbewiki page describing that organism, make a link to it.
Are there any other non-microbes present?
Plants? Animals? Fungi? etc.
Do the microbes that are present interact with each other?
Describe any negative (competition) or positive (symbiosis) behavior
Do the microbes change their environment?
Do they alter pH, attach to surfaces, secrete anything, etc. etc.
Do the microbes carry out any metabolism that affects their environment?
Do they ferment sugars to produce acid, break down large molecules, fix nitrogen, etc. etc.
Current Research
There is currently much research involving the topic of ruminant animals and the microbes that inhabit the rumen.
It has been proven that an increase in stress which a young calf experiences during its early life correlates to a decrease in food intake. Such a decrease in food intake results in a low growth rate of microbes within the rumen lining of the animal. Research is currently being conducted through AgriLabs by performing tests to create new supplemental feed, known as ruminant stimulants, which encourages the growth of rumen microbes during high times of stress. These microbes are essential in breaking down the high fiber diet of ruminant animals by providing the enzymes necessary to break down the fiber. One supplement in particular, Amaferm, contains “all-natural, direct-fed microbial, plus essential vitamins, minerals, and trace minerals” [Ref#]. The goal of this supplement is to assist the microbe Aspergillus oryzae with fermentation so as to help degrade fiber and stimulate an increase in microbial populations within the rumen. AgriLab researchers assure that “Amaferm stimulates the growth rate of these major types of bacteria and anaerobic fungi. Amaferm is one of the most, if not the most, researched direct-fed microbial” [Ref#].
Further research on the topic of the microbe Aspergillus oryzae has found:
Through the Department of Animal Science and Industry at Kansas State University, studies were performed to further test the nature of microbe Aspergillus oryzae’s fermentation extract to see whether it aids in the fermentation process of food digestion and fiber breakdown of ruminant animals. For the study, Holstein steer were fed a diet consisting of alfalfa and hay, which is high in fiber. Samples of the rumen were then gathered for observations. Within a trial period of 96 hours, substantial degradation of fiber in the rumen was evident, as well as an increase in bacterial microbe activity. Inversely, no increase in fungal or protozoal activity was observed.
The experiment proved that Aspergillus oryzae fermentation extract does promote fiber degradation and specifically targets one subgroup of ruminal microbes, bacterial microbes. In accordance to AgriLab’s study of Amaferm, increase in bacteria in the rumen aids in the fermentation process. Fungal and protozoal microbe activity levels were not noticeably affected and thus are not vital to the fermentation process, in comparison to bacterial microbes. [Ref#]
Researchers at Michigan State University’s crop and soil sciences division have been working on ways to convert cellular waste products from plants into an efficient source of fuel and energy through the study of cow bacteria. Within the rumen of the cow are microbes which contain fiber-degrading enzymes that help the cow break down and digest plant fibers such as cellulose, which cows are incapable of doing on their own. Researchers have developed a technique in which they isolate the gene that codes for the enzyme and then insert it into the DNA of corn plants. After allowing the corn plants to mature, it can be seen that they do obtain the same enzyme as the rumen bacteria. The current corn prototype has been given the title Spartan Corn III.
The enzyme currently only operates within the vacuole, the organelle which gathers and removes cellular waste from the cell. With help from the enzyme, this waste is broken down into simple sugars which can then be easily fermented into ethanol. With time, MSU hopes that the enzyme will be able to distribute throughout the entire plant, providing more areas of ethanol fermentation and ultimately, more sites where fuel can be produced. [Ref#]
References
1. Chen, Pei Jun. "Temperature of a Healthy Cow". Hypertextbook. <http://hypertextbook.com/facts/1998/PeiJunChen.shtml>. 1998.
2. Hall, John B, Silver, Susan. "Nutrition and Feeding of the Cow-Calf Herd: Digestive System of the Cow". Virginia Cooperative Extension. <http://www.ext.vt.edu/pubs/beef/400-010/400-010.html#TOC>. June 2001.
3. McCowan, R.P., Cheng, K.J., Costerton, J.W. "Adherent bacterial populations on the bovine rumen wall: distribution patterns of adherent bacteria". PubMed Central. <http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=291309>. January 1980.
4. Whitford, Marc F, Teather, Ronald M, Forster, Robert J. "Phylogenetic analysis of methanogens from the bovine rumen". PubMed Central. <http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=32158>. May 2001.
5. Wilson, Patrick D. "Bovine forestomachs and stomach". <http://www.vetmed.wsu.edu/van308/bovine.htm>. February 2004.
Dewey, Tanya. “Bos Taurus”. Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Bos_taurus.html . 2001.
Woodly, Bill, Metcalf, John A. “Understanding Rumen Function”. Dairy Digest. http://www.shurgain.com/pdf/Winter_2005_DairyDigest.pdf . Winter, 2005.
Massicot, Paul. “Animal Info- Wild Yak”. http://www.animalinfo.org/species/artiperi/bos_mutu.htm . March 2005.
Ruijun, Long. “14 Yak Nutrition- A Scientific Basis”. FAO Corporate Document Repository. http://www.fao.org/docrep/006/AD347E/ad347e0x.htm . 2003.
Massicot, Paul. “Animal Info- Wild Water Buffalo”. http://www.animalinfo.org/species/artiperi/bubaarne.htm . December 2004.
“The Water Buffalo: New Prospects For An Underutilized Animal”. http://www.dalnet.lib.mi.us/gsdl/cgi-bin/library?e=d-000-00---0demo--00-0-0-0prompt-10---4---Document---0-1l--1-en-50---20-help---001-011-1-0utfZz-8-0&a=d&c=demo&cl=CL2.1&d=HASH01d242dc3e08e1fdcf7343bb.8#HASH01d242dc3e08e1fdcf7343bb.8 . 1984.
Wanapat, M. “Swamp Buffalo Rumen Ecology and its Manipulation”. http://www.mekarn.org/procbuf/wanapat.htm . December 2001.
Hall, John B, Silver, Susan. "Nutrition and Feeding of the Cow-Calf Herd: Digestive System of the Cow". Virginia Cooperative Extension. <http://www.ext.vt.edu/pubs/beef/400-010/400-010.html#TOC>. June 2001.
Looper, Michael R, Stokes, Sandra R, Waldner, Dan N, Jordan, Ellen R, “Managing Milk Composition”. Cooperative Extension Services College of Agriculture and Home Economics. http://www.cahe.nmsu.edu/pubs/_d/d-105.pdf . 2006
"Remember the Rumen." Bovine Health Watch. 2007. <http://www.bovinehealthwatch.com/index.php?option=com_content&task=view&id=20&itemid=41>.
Beharka, A.A., Nagaraja, T.G. "Effect of Aspergillus oryzae Fermentation Extract (Amaferm®) on In Vitro Fiber Degradation." Journal of Dairy Science. 1993. <http://www.dairy-science.org/cgi/content/abstract/76/3/812>.
Swain, Heather C., ed. "Gut reaction: Cow stomach holds key to turning corn into biofuel." MSU Today 2008: 3. <http://news.msu.edu/magazine/media/08summer_research.pdf>.
Edited by students of Rachel Larsen
David Becker , Jin Choi , Sarah Flores , Prema Hampapur , Edmond Ho , Adrianne Kurkciyan , Christopher Park , Brian Sun
![[4]](http://www.goodcleantech.com/images/Spartan%20Corn%20III.jpg){kind=link}