What Is the Rumen?

The rumen is the first stomach of a ruminant. The rumen is by far the natural fermenter with the strongest ability to degrade fibrous substances. The internal chyme is divided into three layers (air layer, dense layer and liquid layer). When ruminating, the chyme regurgitates to the mouth and chews again.

The rumen is a cystic digestive organ. The volume of an adult cow is about 56.9L. It is slightly flattened to the left and right and stretched back and forth. Most of them are in the left half of the abdominal cavity, and a few are in the right half of the abdominal cavity. The rumen is long before and after, and is slightly flat on the left and right. There is an obvious horizontal groove on the front and back, called anterior groove and posterior groove. These two grooves extend left and right to form left and right longitudinal grooves. The upper part of the rucksack is the rumen vestibule,

temperature

After the rumen contents reached a relatively stable state, the temperature was 38 to 41 ° C, with an average of 39 ° C. Affected by the type of feed and the temperature of drinking water, it affects the digestion of feed.

pH value

The rumen content pH is the result of the interaction of volatile fatty acids in the chyme with buffer salts in saliva, and the absorption of volatile fatty acids by the rumen epithelium and efflux with the chyme. As a result, the pH range is generally 6 ~ 7. It is mainly affected by the time of feeding and rumination, the ratio of dietary to coarse ratio and the size of dietary particles. The effect on rumen digestion and metabolism is mainly manifested in the degradation of fibrous matter and the absorption of volatile fatty acids.

Redox potential

The rumen content is generally low in oxygen and is commonly used

Rumen is unique as a ruminant

Rumen contents include chyme that enters through the mouth, rumen secretions, and shed tissue.

Rumen microorganisms

Rumen microorganisms include bacteria, methanogens, fungi and protozoa, as well as a few phages. The fermentation of feed by rumen microorganisms is the root cause of the differences in digestion and metabolism of ruminants and non-ruminants. This is the result of mutual selection between the rumen and the microorganism.

Bacteria include: fiber-degrading bacteria, starch-degrading bacteria, semi-fiber-degrading bacteria, protein-degrading bacteria, fat-degrading bacteria, acid-utilizing bacteria, lactic acid-producing bacteria, and other bacteria. Each gram of rumen content contains 10 ⁹ to 10 ¹⁰ bacteria,

Protozoa are mainly ciliates and flagellates. Each gram of rumen content contains 105 to 106 protozoa.

The number of rumen microorganisms varies between different breeds of ruminants. According to Han Zhengkang's research, the number of protozoa and bacteria in the rumen of buffalo is much higher than that of yellow cattle. Mehtiev et al. (1963) found that under the same conditions, buffalo contained 2134 00 protozoa per milliliter of rumen fluid, compared with only 94600 cattle. Devendra (19 85) reported that swamp buffalo has a higher nitrogen utilization rate than Malaysian local cattle (yellow cattle). Although the reason for this phenomenon has not been clearly stated, it is speculated that it is probably due to fermentation caused by different microbial communities in the rumen. It is caused by different types and final fermentation products. Any difference in bacteria, fungi, and protozoa in the rumen of swamp buffalo and local cattle will cause different final fermentation products, which will lead to different digestibility and affect the absorption and utilization of rumen. Devendra (1987) and Wanapat (1989) also reported that swamp buffaloes have a better ability to use nitrogen than cattle, the number of fibrinolytic bacteria in the rumen of buffalo is also greater than that of cattle, and buffalo has a higher ability to break down cellulose ; Sommar t (1993) reported that swamp buffalo have higher numbers of rumen microorganisms than cattle; Wanapat (1999) compared the numbers of rumen bacteria, fungi, and protozoa in swamp buffalo and cattle in the valleys of southeastern Thailand, and found that swamps The number of bacteria in the rumen of buffalo is higher than that of yellow cattle (1.6 × 10 and 1.36 × 10 / ml respectively), and there are more cocci, bacilli and ovum; the number of protozoa in buffalo rumen is lower than that of yellow cattle, Especially the number of ciliates; while the number of fungi in buffalo is significantly higher than that of yellow cattle (7.30 × 10 and 3. 78 × 10 respectively). Observing the fungus anaer omyces sp in the rumen of buffalo under microscope, these results are Previous reports are consistent and provide a basis for finding why swamp buffalo are more adaptable to long-term dry season environments than cattle ^[2] .