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Dairy Science

University of Nebraska - Lincoln

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Cows

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Full-Text Articles in Life Sciences

Breeding Efficiency In Dairy Cattle From Artificial Insemination At Various Intervals Before And After Ovulation, George W. Trimberger Jan 1948

Breeding Efficiency In Dairy Cattle From Artificial Insemination At Various Intervals Before And After Ovulation, George W. Trimberger

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The length of estrus and the time of ovulation were determined for 46 heifers and 86 cows of the Ayrshire, Guernsey, Jersey, and Holstein breeds by testing for end of estrus and ovulation at 2-hour intervals. Services were given by artificial insemination at various intervals before and after ovulation to determine the influence of this factor on the rate of conception. No significant breed or seasonal differences were found for length of estrus and ovulation time after end of estrus among the four dairy breeds represented in the experiment.


The Vitamin A Content Of Soybean Silage And Of A.I.V., Molasses, And Common Corn Silages, And The Effect Of Feeding These Materials Upon The Vitamin A Content Of Milk, I. L. Hathaway, H. P. Davis, J. C. Brauer Jun 1938

The Vitamin A Content Of Soybean Silage And Of A.I.V., Molasses, And Common Corn Silages, And The Effect Of Feeding These Materials Upon The Vitamin A Content Of Milk, I. L. Hathaway, H. P. Davis, J. C. Brauer

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

A study was made of the vitamin A content of soybean silage, and of A.l.V., molasses, and common corn silage. The silages were fed to groups of cows and the vitamin A content of their milk determined. The vitamin A determinations were made by feeding the silage or the milk to groups of rats whose body stores of this vitamin had been depleted by being fed a vitamin-A-deficient ration. Approximately 780 rats were used in these experiments. There were no apparent ill effects of feeding as much as 3.2 grams of the A.l.V. silage per rat per day for eight …


The Vitamin A Content Of Skimmilk, Standardized Milk, And Cream From Different Breeds Of Cows, I. L. Hathaway, H. P. Davis Dec 1933

The Vitamin A Content Of Skimmilk, Standardized Milk, And Cream From Different Breeds Of Cows, I. L. Hathaway, H. P. Davis

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

A study was made of the vitamin A content of skimmilk, of milk standardized by the addition of separated milk, and of cream. Rats whose body stores of vitamin A had been depleted by being fed a vitamin A deficient ration were fed either skimmilk, standardized milk, or cream as a source of vitamin A. Approximately 750 rats were used in nine experiments. From the results of these experiments the following conclusions were drawn: (1) that the vitamin A content of milk is associated largely with the butterfat and that separated milk containing a small quantity of fat contains only …


The Vitamin A Content Of The Milk Of Holstein, Ayrshire, Jersey, And Guernsey Cows, H. P. Davis, I. L. Hathaway Feb 1931

The Vitamin A Content Of The Milk Of Holstein, Ayrshire, Jersey, And Guernsey Cows, H. P. Davis, I. L. Hathaway

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

A comparative study of the vitamin A content of milk produced by Holstein, Ayrshire, Jersey, and Guernsey cows was made by comparing the growth produced by 560 rats receiving milk from these breeds as their only source of vitamin A. The results showed some slight irregular differences in the gains produced by the milk from the different breeds. When these differences were considered in view of the individual variation of the experimental animals, they appeared negligible. This conclusion was substantiated by a statistical examination of the data. From the results of this study in which the experiments were duplicated, it …