a
Please use this identifier to cite or link to this item:
http://hdl.handle.net/123456789/7396
Title: | Comparative assessment of the adaptive capacity of different indigenous breed goats to summer heat stress based on changes in phenotypic traits |
Authors: | Sejian, V Aleena Joy |
Keywords: | Adaptation Osmanabadi goats Climate change Heat stress Cortisol Livestock production Indigenous breed Drinking frequency Goat Aspartate aminotransferase |
Issue Date: | 2017 |
Publisher: | Academy of Climate Change Education and Research Vellanikkara |
Abstract: | A study was conducted to evaluate the differences in the thermo-tolerant abilities of three indigenous goat breeds (Osmanabadi, Malabari and Salem Black) to heat stress challenges. The primary objective of the study was to compare the adaptive ability of two indigenous goat breeds (Malabari and Salem Black) when they were shifted from their native tract to a new agro-ecological zone with the local breed (Osmanabadi) during heat stress exposure. The adaptive capabilities of these breeds were assessed based on the changes in their behavioral, physiological, blood biochemical and endocrine responses and peripheral blood mononuclear cell heat shock protein 70 (PBMC HSP70) gene expression patterns. Thirty six 10 months to one year old female goats were randomly allocated into six groups of six animals each as OCON (n=6; Osmanabadi control), OHS (n=6; Osmanabadi heat stress), MCON (n=6; Malabari control), MHS (n=6; Malabari heat stress), SCON (n=6; Salem Black control) and SHS (n=6; Salem black heat stress). The OCON, MCON and SCON animals were maintained in the shed while OHS, MHS and SHS animals were exposed to summer heat stress between 10:00 h to 16:00 h. All the animals had access to ad-libitum feed and water. The duration of the study was 45 days. Results indicated that among the behavioural variables studied, both drinking frequency (DF) and water intake (WI) were significantly higher (P<0.01) in heat stress groups of all the three breeds as compared to their respective control groups. Further, significantly lower (P<0.05) urinating frequency (UF) and higher (P<0.05) rumination time (RuT) was recorded in MHS as compared to other stress groups. The heat stress treatment significantly (P<0.05) lowered the respiration rate (RR) and rectal temperature (RT) in the morning while significantly (P<0.01) increased all the physiological variables such as RR, pulse rate (PR) and RT in all the three breeds during afternoon. Further, the results indicated that only breed differences (P<0.01) were established for different biochemical variables in the study while the heat stress did not alter these parameters. However, heat stress significantly (P<0.05) increased the plasma cholesterol in MHS group while significantly lowered (P<0.05) plasma triglyceride in both OHS and SHS groups. Further, aspartate aminotransferase (AST) showed significant variation for both breed (P<0.05) as well as treatment (P<0.05) effect. In addition, heat stress significantly increased (P<0.01) plasma cortisol and significantly decreased (P<0.05) plasma aldosterone in only MHS group. Furthermore, heat stress induced PBMC HSP70 expression was significantly higher (P<0.05) in OHS and MHS as compared to SHS group. Thus, it can be concluded from the results that although Malabari breed which is well known for its survival in harsh environment in its native tract could not adapt well to the new locality with much lower magnitude of heat stress. The less severe influence of heat stress on the various biological functions of Salem Black breed as compared to other two breeds clearly indicated the superior adaptability of this breed to survive in different agro-ecological zones. Further, the study also identified RR, RT, plasma cortisol and PBMC HSP70 to be the reliable biological markers for evaluating the thermo-tolerant capacity of indigenous goat breeds. |
URI: | http://hdl.handle.net/123456789/7396 |
Appears in Collections: | PG Thesis |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
174254.pdf | 22.39 MB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.