The effect of ortho, meta, pyro, and phytin phosphates upon cellulose digestion by rumen microorganisms in vitro

Microorganisms have long been known to play an integral part in the nutrition of ruminant animals. The requirement of rumen microbes for specific nutrients has become an important area of investigation. In recent years considerable research has been conducted concerning minerals that would increase microbial activity in the rumen. Through increased rumen microbial activity, cattle and sheep can be expected to better utilize roughages and thus male more economical gains.

Extensive studies have shown that phosphorus is particularly important from the standpoint of efficient feed utilization by ruminants. It is believed that phosphorus stimulates rumen microbial activity which in turn enhances feed utilization. Insufficient data are available, however, to give a clear understanding of the influence of the phosphorus-microorganism relationship upon feed utilization.

The introduction of suitable artificial rumen techniques has enabled a deeper understanding of the mineral requirements of rumen microorganisms. In addition, it has presented an excellent method for the study of the requirements of phosphorus by rumen microorganisms. Although one can not extrapolate laboratory data to apply to the live animal, the artificial rumen technique is valuable as a preliminary method to explore rumen nutritional problems.

Several reports compare the effect of phosphorus from various phosphorus sources of ruminants. In many cases these sources were various compounds of the same chemical form of phosphorus. No data are available comparing the ortho, meta, pyro, and phytate forms of phosphorus, which are the common chemical forms of this element. More complete knowledge of the availability of phosphorus from these chemical forms to rumen microorganisms would be of basic interest and would, in all probability, be of practical importance.

There were three objectives of the present investigation: (1) to determine if rumen microorganisms were critical in their requirement of phosphorus as to amount and source; (2) to determine if the ortho, meta, pyro, and phytate forms were utilized by rumen microorganisms; and (3) to determine the relative availability of the above forms.