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Full-Text Articles in Life Sciences

Artificial Insemination And Fetal Programming In Beef Production Systems, Dempster Christenson May 2024

Artificial Insemination And Fetal Programming In Beef Production Systems, Dempster Christenson

Department of Animal Science: Dissertations, Theses, and Student Research

Pregnancy to artificial insemination and late gestation fetal programming of the next calf crop are central to genetic development, reproductive longevity, calf crop productivity, and efficiency of cow/calf ranching. The purposes of this research are to find methods to improve pregnancy rate to artificial insemination, the growth and reproductive health of pregnant heifers, and the productivity of their offspring. In the first of four studies we found that extending the period of progesterone administration in an estrus synchronization protocol did not significantly hasten estrus response or increase pregnancy rate to artificial insemination, but timing of estrus within the melengestrol acetate …


Comparison Of Transcervical Insemination Versus Surgical Insemination Methods In Dogs At A Veterinary Clinic In Lincoln, Nebraska, Lauren Ahlers Mar 2022

Comparison Of Transcervical Insemination Versus Surgical Insemination Methods In Dogs At A Veterinary Clinic In Lincoln, Nebraska, Lauren Ahlers

Honors Theses

Artificial insemination paved the way for many advancements in reproductive technology. Two common artificial insemination methods recommended for use with frozen semen are transcervical insemination and surgical insemination. To better understand the conception rates of dogs for each method, data was collected from Hillcrest Animal Clinic. The data suggested that neither transcervical insemination nor surgical insemination was significantly better than the other. 50% of the dogs conceived when inseminated using the transcervical method, and 54.5% of the dogs conceived when inseminated using the surgical method. Based on the results, more data needs to be collected on both insemination procedures to …


Fertility Of Semen Used In Commercial Production And The Impact Of Sperm Numbers And Bacterial Counts, D. L. Reicks, Donald G. Levis Nov 2008

Fertility Of Semen Used In Commercial Production And The Impact Of Sperm Numbers And Bacterial Counts, D. L. Reicks, Donald G. Levis

Department of Animal Science: Faculty Publications

The objective was to monitor sperm counts and bacterial presence on randomly pooled semen doses over 3 years and to determine effects on the farrowing rate and total born in two large farm systems, each serviced by its own boar stud. Sperm counts were divided into increments of 0.5 × 109 for data analysis. There was no effect of sperm count or the presence of bacteria on farrowing rate (n = 9502 observations). Furthermore, based on 7311 observations, there was no effect of the mere presence of bacteria on total born, but sperm count had a significant effect …


The Effects Of Semen Collection On Fertility In Captive, Naturally Fertile, Sandhill Cranes, Guojun Chen, George F. Gee, Jane M. Nicolich, Joanna A. Taylor Jan 2001

The Effects Of Semen Collection On Fertility In Captive, Naturally Fertile, Sandhill Cranes, Guojun Chen, George F. Gee, Jane M. Nicolich, Joanna A. Taylor

Proceedings of the North American Crane Workshop

We tested to see if semen collection interferes with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile, Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had previously produced fertile eggs. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection had minimal effect on semen quality and semen quantity. Semen volume, sperm density, sperm motility, sperm morphology, sperm viability, sperm number …


Natural Fertility In Whooping Cranes And Mississippi Sandhill Cranes At Patuxent Wildlife Research Center, Jane M. Nicolich, George F. Gee, David H. Ellis, Scott G. Hereford Jan 2001

Natural Fertility In Whooping Cranes And Mississippi Sandhill Cranes At Patuxent Wildlife Research Center, Jane M. Nicolich, George F. Gee, David H. Ellis, Scott G. Hereford

Proceedings of the North American Crane Workshop

The first fertile whooping crane (Grus americana; WC) egg produced through natural breeding at Patuxent Wildlife Research Center (patuxent) was laid in 1991. Prior to that time, all fertile whooping crane eggs were the result of artificial insemination. Since 1991, eight different whooping crane pairs at Patuxent have produced fertile eggs through natural breeding. Mean fertility averages over years for each pair range from 40% to 93 %. Fertility rates for each pair also vary greatly between years, from 0% to 100%, but the causes of the variance are unknown. Experiences with natural fertility in Mississippi sandhill cranes ( …


Recent Advances In Scheduling Strategies And Practical Techniques In Crane Artificial Insemination, Scott R. Swengel, Monica L. Tuite Jan 1997

Recent Advances In Scheduling Strategies And Practical Techniques In Crane Artificial Insemination, Scott R. Swengel, Monica L. Tuite

Proceedings of the North American Crane Workshop

We analyzed fertility patterns of 339 eggs laid 1985-93 at the International Crane Foundation by cranes whose sole means of fertility was artificial insemination (AI). Ten of 15 crane species were studied. Fertility rates increased significantly (P < 0.05) with (I) higher sperm density, (2) greater sperm motility, and (3) 2 vs. 1 vs. 0 inseminations 4-7 days before oviposition. Semen sample size was inversely related to sperm density and had no strong relationship with egg fertility. Inseminations less than 2.5-3.0 days before an egg is laid are probably too late to contribute to fertilizing the egg but may contribute substantially to fertilizing the next egg. We also describe practical knowledge gained during the past 10 years that apply to certain species or situations. Wattled cranes (Bugeranus carunculatus) have a long fertile period post-AI (up to 16 days), but may require more careful methods and special AI scheduling strategies. We also describe techniques for AI just after oviposition that are especially beneficial for Siberian cranes (Grus leucogeranus), and methods for maximizing sample delivery to the female.


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 May 1948

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 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.


Conception Rate In Dairy Cattle By Artificial Insemination At Various Stages Of Estrus, George W. Trimberger, H. P. Davis Apr 1943

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 …