Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle

Persistent Link:
http://hdl.handle.net/10150/193620
Title:
Effects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattle
Author:
Bailey, Clayton R.
Issue Date:
2006
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Two trials were conducted to evaluate the effects of gender on optimal CP concentrations (TRIAL 1) and gender and anabolic implants on the somatotropic axis in feedlot cattle (TRIAL 2). More specifically, the objective of TRIAL 1 was to examine the effects of 3 dietary CP concentrations on performance, carcass characteristics, and serum urea nitrogen (SUN) in finishing steers and heifers and the objective of TRIAL 2 was to evaluate the effects of ovariectomy (OVX) and implantantation (200 mg of trenbolone acetate and 28 mg of estradiol benzoate; Synovex-Plus) on performance, serum urea nitrogen (SUN), serum IGF-1, and mRNA expression of hepatic IGF-1, GH receptor, and E receptor-α as well as pituitary GH, E receptor-α and GHRH receptor in feedlot heifers. TRIAL 1 results indicated that ADG was optimized when both steers and heifers were fed 12.5% CP and G:F was optimized for steers fed 12.5% CP but heifer G:F was optimal at 14.0% CP. Feeding diets containing 11.0% CP appears to cause a protein deficiency in both steers and heifers. TRIAL 2 data indicated that gender had no influence on performance or SUN in feedlot heifers. Serum IGF-1 is increased more in OVX heifers than intact heifers due to a greater response to implantation from the OVX heifers. However, the reason for the extra increase in serum IGF-1 is not clear, although trends in gene expression analysis suggest the possibility that the increased serum IGF-1 may be controlled outside of the somatotropic axis. Further research is warranted to examine the effects of OVX and anabolic implants on the somatotropic axis.
Type:
text; Electronic Dissertation
Keywords:
Crude Protein; Beef Cattle; Somatotropic Axis; Anabolic Implants; Gene Expression
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Animal Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Duff, Glenn C.
Committee Chair:
Duff, Glenn C.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleEffects of Gender on Protein Requirements and the Somatotropic Axis in Feedlot Cattleen_US
dc.creatorBailey, Clayton R.en_US
dc.contributor.authorBailey, Clayton R.en_US
dc.date.issued2006en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractTwo trials were conducted to evaluate the effects of gender on optimal CP concentrations (TRIAL 1) and gender and anabolic implants on the somatotropic axis in feedlot cattle (TRIAL 2). More specifically, the objective of TRIAL 1 was to examine the effects of 3 dietary CP concentrations on performance, carcass characteristics, and serum urea nitrogen (SUN) in finishing steers and heifers and the objective of TRIAL 2 was to evaluate the effects of ovariectomy (OVX) and implantantation (200 mg of trenbolone acetate and 28 mg of estradiol benzoate; Synovex-Plus) on performance, serum urea nitrogen (SUN), serum IGF-1, and mRNA expression of hepatic IGF-1, GH receptor, and E receptor-α as well as pituitary GH, E receptor-α and GHRH receptor in feedlot heifers. TRIAL 1 results indicated that ADG was optimized when both steers and heifers were fed 12.5% CP and G:F was optimized for steers fed 12.5% CP but heifer G:F was optimal at 14.0% CP. Feeding diets containing 11.0% CP appears to cause a protein deficiency in both steers and heifers. TRIAL 2 data indicated that gender had no influence on performance or SUN in feedlot heifers. Serum IGF-1 is increased more in OVX heifers than intact heifers due to a greater response to implantation from the OVX heifers. However, the reason for the extra increase in serum IGF-1 is not clear, although trends in gene expression analysis suggest the possibility that the increased serum IGF-1 may be controlled outside of the somatotropic axis. Further research is warranted to examine the effects of OVX and anabolic implants on the somatotropic axis.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectCrude Proteinen_US
dc.subjectBeef Cattleen_US
dc.subjectSomatotropic Axisen_US
dc.subjectAnabolic Implantsen_US
dc.subjectGene Expressionen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAnimal Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorDuff, Glenn C.en_US
dc.contributor.chairDuff, Glenn C.en_US
dc.contributor.committeememberAllen, Ronald E.en_US
dc.contributor.committeememberCuneo, S. Pederen_US
dc.contributor.committeememberMarchello, John A.en_US
dc.identifier.proquest1979en_US
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