Search PubMed⌕ Search

Biomedical subjects

K el-Shazly

Publications and source records attributed to K el-Shazly.

15 recordsLinked to original sources

Evaluation of a method of measuring fermentation rates and net growth of rumen microorganisms.

The method of el-Shazly and Hungate for measuring gas production in rumen contents was slightly modified and used throughout this investigation. The variation in the fermentation rates due to samples collected separately from a sheep fed on hay was less than 2%. When samples obtained through a stomach tube were compared with samples collected through the rumen fistula, the variation was about 3%. The rates of gas and acid production were approximately similar in samples obtained from the rumen at the same time when no sodium bicarbonate was added. During in vitro incubation of whole ruminal contents, there was a highly significant correlation between the net growth rate values (obtained by using fermentation capacity as an index) and the change in concentration of viable rumen bacteria or total ciliate protozoa.

Acids↗

Some factors affecting fermentation capacity and net growth of rumen microorganisms.

The fermentation rate of rumen microorganisms obtained from a sheep fed on hay was determined at different hours after feeding. The highest rate of fermentation was obtained immediately after feeding whereas the lowest rate was always before feeding. The effect of adding glucose, sucrose, and starch alone or in combination with urea, sodium citrate, or succinic acid on the maximal fermentation rate was studied. In no case was the maximal fermentation rate greater than that obtained in the presence of concentrate and straw. An investigation on the effect of C/N ratios, dilution, and substrate concentration on the net growth of rumen microorganisms was undertaken. The highest net growth value was obtained with a C/N ratio of 16.5 to 17.5, which is the ratio found for the ration fed to the animal. It was possible to increase net growth approximately threefold by using the proper dilution and fivefold by using the proper feed concentration.

Animal Feed↗

Method for measuring diaminopimelic acid in total rumen contents and its application to the estimation of bacterial growth.

Diaminopimelic acid (DAP) was measured in rumen samples for which growth rate had previously been estimated from changes in fermentation capacity. The growth measurements by the two methods agreed within the experimental error. Agreement between the rate of bacterial growth (DAP) and total microbial growth (fermentation capacity) suggests that the protozoa also grow at about this rate.

Animal Feed↗