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Physiology And Ecology Of Dispersal Polymorphism In Insects, Anthony J. Zera, Robert F. Denno
Physiology And Ecology Of Dispersal Polymorphism In Insects, Anthony J. Zera, Robert F. Denno
Anthony Zera Publications
Studies of dispersal polymorphism in insects have played a pivotal role in advancing our understanding of population dynamics, life history evolution, and the physiological basis of adaptation. Comparative data on wing-dimorphic insects provide the most definitive evidence to date that habitat persistence selects for reduced dispersal capability. The increased fecundity of flightless females documents that a fitness tradeoff exists between flight capability and reproduction. However, only recently have studies of nutrient consumption and allocation provided unequivocal evidence that this fitness trade-off results from a trade-off of internal resources. Recent studies involving wing-dimorphic insects document that flight capability imposes reproductive penalties …
Development Of Gilts And Boars For Efficient Reproduction, Donald G. Levis, Vernon D. Leibbrandt, Dale W. Rozeboom
Development Of Gilts And Boars For Efficient Reproduction, Donald G. Levis, Vernon D. Leibbrandt, Dale W. Rozeboom
Department of Animal Science: Faculty Publications
Successful introduction of replacement gilts and boars into the breeding herd is an important aspect of breeding herd efficiency. To attain herd efficiency, females must ovulate adequate numbers of viable ova, express estrus, show willingness to mate, and conceive in a regular manner. Males must produce adequate numbers of fertile spermatozoa, possess ability and show willingness to mate, and produce high-conception rates. If these qualities are properly developed, pregnancy rate and litter size will be maximized.
The Effect Of Disturbance On The Reproduction And Management Of Captive Cranes, Claire M. Mirande, James W. Carpenter, Ann M. Burke
The Effect Of Disturbance On The Reproduction And Management Of Captive Cranes, Claire M. Mirande, James W. Carpenter, Ann M. Burke
Proceedings of the North American Crane Workshop
A retrospective analysis of egg laying histories and observations of crane pairs at the International Crane Foundation and the Patuxent Wildlife Research Center indicates that disturbance associated with captivity has adverse impacts on captive breeding. Females on public display laid significantly fewer eggs than those off display (P < 0.05). Crane pairs moved to other pens (other than adjacent pens) or hetween facilities laid slightly fewer eggs than those birds which were not moved. although the results were not statistically significant (P = 0.188). Pen design and construction also appeared to have adverse impacts on breeding. In addition, human activities, intraspecific interactions, and rearing methods influence a bird's response to disturbance, and, therefore, these factors must also be considered in an effective crane management program. Modifying procedures to minimize disturbance, timing necessary disturbances after the breeding and molt seasons, and carefully monitoring birds for signs of stress can result in increased reproductive potential for captive, endangered cranes.
Ec97-219 1997 Nebraska Swine Report, Duane Reese
Ec97-219 1997 Nebraska Swine Report, Duane Reese
University of Nebraska-Lincoln Extension: Historical Materials
The 1997 Nebraska Swine Report was prepared by the staff in Animal Science and cooperating Departments for use in Extension, Teaching and Research programs. This publications deals with research on swine reproduction, breeding, health, nutrition, economics, and housing.
G97-1324 Beef Cattle Implant Update, Dicky D. Griffin, Terry L. Mader
G97-1324 Beef Cattle Implant Update, Dicky D. Griffin, Terry L. Mader
University of Nebraska-Lincoln Extension: Historical Materials
This NebGuide discusses the mechanism of action and use strategies for growth promoting implants, including expected responses and cost analysis.
Introduction
Growth promoting implants have been used extensively in beef production for over 30 years. Significant changes in implants and implanting strategies have occurred. Prior to 1987, available implants were estrogenic agents which metabolically enhanced nutrient use to enhance growth. These products improved feed efficiency 5-10 percent and daily gains from 5-15 percent. In 1987, the androgenic (tissue building) agent, trenbolone acetate, was approved for use in growth promoting implants. This compound had an additive effect with existing estrogenic implants. …
Mp68 1996-98 Dairy Report
University of Nebraska-Lincoln Extension: Historical Materials
Annual Report of University of Nebraska-Lincoln Dairy Research for 1997-1998. Topics include:
Time of Initiating Dietary Fat Supplementaion on Lactation and Reproduction
A Soyhull:Soy Lecithin Soapstock Mixture for Early Lactation Dairy Cows
Nonenzymatically Browned Soybeans for Dairy Cattle
Feather and Blood Meal Combination for Lactating Dairy Cows
Impact of Nonfiber Carbohydrate Concentration on Forage Fiber Digestion
Sulfite Liquor-Treated Meat and Bone Meal for Dairy Cows
The OTHER Causes of Infectious Diseases
Test Day Genetic Evaluations
Income and Herdlife
Maternal Genetic and Cytoplasmic Effects in Dairy Cattle
Financial and Management Survey of Nebraska Dairy Producers
Free-Stall Design and Maintenance
Horizontal Silos …
Ec97-274 Management Of Replacement Gilts For Efficient Reproduction, Donald G. Levis
Ec97-274 Management Of Replacement Gilts For Efficient Reproduction, Donald G. Levis
University of Nebraska-Lincoln Extension: Historical Materials
Successfully introducing replacement gilts into the breeding herd is an important aspect of breeding herd efficiency. To attain herd efficiency, females must ovulate adequate numbers of viable ova, express estrus, show willingness to mate and conceive in a regular manner. If these qualities are properly developed, pregnancy rate and litter size will be maximized. A gilt development and management program needs to be designed for gilts from birth to farrowing their first litter.
1997 Nebraska Swine Report, Duane E. Reese
1997 Nebraska Swine Report, Duane E. Reese
University of Nebraska-Lincoln Extension: Historical Materials
This publication was prepared by the staff in Animal Science and cooperating Departments for use in Extension, Teaching and Research programs. It deals with the results that were done in reproduction, breeding, health, nutrition, seconomics and housing of swine.