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Full-Text Articles in Animal Sciences
The Influence Of Length Of Storage Of Bovine Semen On Conception Rate Under Field Conditions, A. B. Schultze, H. P. Davis, C. T. Blunn, M. M. Oloufa
The Influence Of Length Of Storage Of Bovine Semen On Conception Rate Under Field Conditions, A. B. Schultze, H. P. Davis, C. T. Blunn, M. M. Oloufa
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
It is the purpose of this study to determine whether under conditions of routine handling in artificial breeding associations there is a decline in semen fertility from day to day and also to determine the magnitude of this decline. Tabulation of such data will not only be of value in determining the effect of frequent semen collection on the over-all artificial breeding results but will also serve as a basis of comparison in investigational work directed toward increasing the efficiency of artificial breeding.
Breeding Efficiency In Dairy Cattle From Artificial Insemination At Various Intervals Before And After Ovulation, George W. Trimberger
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.
Conception Rate In Dairy Cattle By Artificial Insemination At Various Stages Of Estrus, George W. Trimberger, H. P. Davis
Conception Rate In Dairy Cattle By Artificial Insemination At Various Stages Of Estrus, George W. Trimberger, H. P. Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
A breeding experiment with 295 dairy cows and heifers of the Jersey, Guernsey, Ayrshire, and Holstein breeds was conducted in the University of Nebraska dairy herd. The females were given artificial services at various stages of estrus to determine the effect of time of service upon conception. The results obtained indicate the potential benefits in higher percentage of conception in females bred during the middle of estrus, toward the end of estrus, and those bred in full heat and rebred in 24 hours. The latter is usually not very practical, especially in artificial breeding rings, but there are occasions when …
Influence Of Age Of Dairy Cattle And Season Of The Year On The Sex Ratio Of Calves And Services Required For Conception, R. F. Morgan, H. P. Davis
Influence Of Age Of Dairy Cattle And Season Of The Year On The Sex Ratio Of Calves And Services Required For Conception, R. F. Morgan, H. P. Davis
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
The present study was based on records of the dairy herd of the University of Nebraska for the period 1896 to 1934, and covers five breeds, Holsteins, Jerseys, Guernseys, Ayrshires, and milking Shorthorns. In all, 2,090 cows have been included. The purpose was to determine the influence of the age of the bull, the age of the cow, and the season of the year upon the number of services required for conception, and to determine also the influence of these factors upon the sex ratio of calves born, number of twins born, and the percentage of abortion.