Impact of body condition on plasma leptin and insulin-like growth factor-I concentrations in stallions and geldings /

Bibliographic Details
Main Author:	Chancellor, Tommy Neal
Other Authors:	Vogelsang, Martha M. (Thesis advisor)
Format:	Thesis eBook
Language:	English
Published:	[College Station, Tex.] : [Texas A&M University], [2010]
Subjects:	Major animal science. insulin-like I leptin body conition
Online Access:	Link to OAK Trust copy

Description
Abstract:	The objective of this study was to more clearly define the relationship between body condition, plasma leptin and insulin-like growth factor-I (IGF-I) in stallions and geldings in moderate (5.0-5.5) versus fleshy (7.0-7.5) body condition. Data analyses of physical measurements showed that there was a difference for BCS (P<0.001) even though the fat group only achieved a mean BCS of 6.3 [plus or minus] 0.2 as compared with a mean BCS of 5.3 [plus or minus] 0.1 for the moderate group. Differences also existed for rump fat (P<0.05) and percent body fat (P<0.05) between BCS groups. Analysis of physical measurements revealed that there was no sex effect as geldings and stallions within each group were not significantly different. Analysis of plasma leptin concurred with previous reports as a difference (P<0.001) existed between the BCS groups. Mean leptin concentrations were 2.13 [plus or minus] 0.1 ng/ml for the fat group and 1.44 [plus or minus] 0.1 ng/ml for the moderate group. After normalization of the data, changes in leptin concentrations still revealed a significant difference (P<0.05) between BCS groups, yet no difference in leptin concentrations between stallions and geldings was seen. Dexamethasone (DEX) treatment on d 0 caused a subsequent 24 h rise in plasma leptin in both groups. Analysis of plasma IGF-I revealed no difference in IGF-I concentrations between BCS groups. Mean plasma IGF-I was 347.2 [plus or minus] 11.4 ng/ml for the fat group and 344.3 [plus or minus] 10.0 ng/ml for the moderate group. There was however a difference (P<0.05) between geldings and stallions. Geldings exhibited an overall mean plasma IGF-I concentration of 360.6 [plus or minus] 9.1 ng/ml with stallions exhibiting a mean IGF-I concentration of 329.1 [plus or minus] 12.1 ng/ml. The post DEX challenge rise seen with leptin was not evident when analyzing the change in plasma IGF-I concentrations. In conclusion, the data presented herein have provided a more accurate profile of circulating concentrations of leptin and IGF-I in stallions and geldings of moderate and fleshy body condition.
Item Description:	"Major Subject: Animal Science" Title from author supplied metadata (automated record created 2010-03-12 12:08:51). Electronic resource.
Physical Description:	1 online resource.
Bibliography:	Includes bibliographical references.