Call number: LD2668 .T4 1934 K61

Call number: LD2668 .T4 1958 M64

Call number: LD2668 .T4 1955 M85 / Master of Science

No description available.

No description available.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: William W. Saylor, Dept. of Animal and Food Sciences. Includes bibliographical references.

Endemic populations of pandora moths (Co/oradia pandora Blake), a defoliator of western pine forests, proliferated to epidemic levels in central Oregon in 1986 and increased dramatically through 1 994. Golden-mantled ground squirrels (Spermophilus lateralis Say) consume adult pandora moths, but reject nutritionally valuable eggs from gravid females. Feeding trials with captive S. lateralis were conducted to identify the mode of egg protection. Chemical constituents of fertilized eggs were separated through a polarity gradient of solvent extractions. Consumption of the resulting hexane, dichloromethane, and water egg fractions, and the extracted egg tissue residue, was evaluated by randomized 2-choice feeding tests. Consumption of four physically distinct egg fractions (whole eggs, "whole" egg shells, ground egg shells, and egg contents) also was evaluated. These bioassays indicated that C. pandora eggs are not protected chemically, however, the egg shell does inhibit S. lateralis consumption. Egg protection is one mechanism that enables C. pandora to persist within the forest food web. Spermophilus lateralis, a common and often abundant rodent of central Oregon pine forests, is a natural enemy of C. pandora moths and pupae, but not eggs. / Graduation date: 1995

Induced molting is process used by commercial producers to extend the reproductive life of a laying hen. Typically, producers deprive hens of feed for a period of 7-14 days while reducing the amount of light exposure to the hens. This allows for regression of the reproductive tract and for a second cycle of egg production to occur. However, induced molting by feed deprivation has been shown to increase the hen's risk of becoming infected with pathogenic bacteria, such as Salmonella. This increased risk could mean an increase in contaminated eggs or egg products, which causes concerns for public health. This combined with increasing pressure on egg producers from animal welfare organizations has prompted the investigation of diets that would provide available energy for the hens, while still inducing a molt that is economically advantageous to producers. Alfalfa, provided in meal or pelleted form, provides only 1/2 the metabolizable energy and 1/4 of the calcium required of a laying hen that is reproductively active. Due to the decrease in nutrients, alfalfa was investigated as an alternative to feed deprivation. Studies were conducted to assess egg quality, egg production, consumer acceptance, and hen physiology.

Induced molting is process used by commercial producers to extend the reproductive life of a laying hen. Typically, producers deprive hens of feed for a period of 7-14 days while reducing the amount of light exposure to the hens. This allows for regression of the reproductive tract and for a second cycle of egg production to occur. However, induced molting by feed deprivation has been shown to increase the hen's risk of becoming infected with pathogenic bacteria, such as Salmonella. This increased risk could mean an increase in contaminated eggs or egg products, which causes concerns for public health. This combined with increasing pressure on egg producers from animal welfare organizations has prompted the investigation of diets that would provide available energy for the hens, while still inducing a molt that is economically advantageous to producers. Alfalfa, provided in meal or pelleted form, provides only 1/2 the metabolizable energy and 1/4 of the calcium required of a laying hen that is reproductively active. Due to the decrease in nutrients, alfalfa was investigated as an alternative to feed deprivation. Studies were conducted to assess egg quality, egg production, consumer acceptance, and hen physiology.