Report on the Agricultural Experiment Stations, 1952 Page: 85
The following text was automatically extracted from the image on this page using optical character recognition software:
DAIRY PRODUCTION 85
According to the Michigan station, large amounts of antibiotics
inhibit the growth of certain types of rumen flora; however, in in-vitro
trials they found that very low concentrations of penicillin and certain
other antibiotics, except chloromycetin, stimulated the growth of cellulolytic
rumen micro-organisms. The Illinois, Michigan, and Vermont
stations obtained best results when the calf starter contained both
aureomycin and vitamin B12. The substitution of cobalt for vitamin
B12 has not proven successful for young calves, although supplying
cobalt to older ruminants appears to stimulate the synthesis of vitamin
B12 in the rumen (by increasing the growth of certain bacteria).
The feeding of vitamin B12 does not relieve cobalt deficiency symptoms,
according to the Wisconsin station. (Antibotics have not affected milk
production, altered feed consumption, or been transmitted into the
milk of cows, according to the New York (Cornell) station.
Calves fed a vitamin-D-deficient diet at the New Hampshire station
developed the known symptoms of such a diet-rickets, arched back,
large knees, sore joints, and underweight. In addition to these apparent
adverse effects on the digestibility of minerals, the calves
showed a definite tendency to use protein less efficiently, indicating
poor digestion and inefficient absorption.
The Ohio station has previously reported good results from "inoculating"
young calves with the rumen flora of mature animals.
These added micro-organisms are suposed to make it possible for the
calves' rumen to digest roughage quicker than when the animal is
allowed to develop its own flora in the natural course of time, around
2 to 3 months of age. In the Ohio experiments fresh cud material
was used. The Wyoming station now reports that commercially prepared
dry cud sold for this purpose has very little value. Up to
8 weeks of age calves at the Oklahoma station grow equally well,
irrespective of whether they received any hay or not. And up to 16
weeks of age either good quality alfalfa or timothy hay gave comparable
Radioactive Isotopes in Dairy Research
Numerous stations are using radioactive isotopes to unravel the
intricate physiological processes involved in converting roughage and
certain inorganic compounds into meat and milk. The problem of the
digestibility of a feed is sometimes complicated by the fact that certain
fragments may be absorbed into the bloodstream, used by the
body, and then re-excreted into the gut. By means of "tagged"
(radioactive) compounds the California station found that a cow
on a high food intake digested only 12 percent of the phosphorus in
her ration, according to former measurements of digestibility. With
the new method 50 percent of the phosphorus in the feed was shown
to have served the body in one way or another. Another cow on a low
food intake excreted even more phosphorus in her feces than she consumed
in her feed, but when radioactive P32 was given the results
proved she had used 64 percent of the ingested phosphorus before
returning part of it to the gut.
The Florida station, using a slightly different technique, found that
on a high calcium, low phosphorus diet insoluble calcium phosphates
are formed in the lower part of the intestine, thus preventing the
body from utilizing badly needed phosphorus,
Here’s what’s next.
This book can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Book.
United States. Office of Experiment Stations. Report on the Agricultural Experiment Stations, 1952, book, January 1953; Washington D.C.. (digital.library.unt.edu/ark:/67531/metadc5990/m1/87/: accessed September 21, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.