Physiologic responses of heat-stressed broiler chickens (Gallus gallus domesticus L.) subjected to early thermal conditioning and feed restriction / Hyde Duran Nadela ; Severino S. Capitan, chair, advisory committee.

Date

10-2011

Abstract

Three experiments were conducted to evaluate the physiologic consequences of early thermal conditioning (ETC) and early feed restrictions (EFR) in broiler chickens. In study 1, chicks were exposed to ETC (ambient temperature of 36±1°C) for 24 h at d 3; 12 h at d 3 and 5; 8 h at d 3, 5 and 7; and control (no exposure). In study 2, chicks were subjected to 60% feed restriction (EFR)( at d 4, 5 and 6; d 7, 8 and 9; d9, 10 and 11; and control (ad libitum feeding) A combination of ETC (38°C for 8 h at d 3, 5 and 7) and EFR (70% feed restriction at d 4, 6 and 8) using a 2x2 factorial design was employed in study 3. Growth, body temperature, respiratory rate, total RBC, carcass and bone ash were not affected regardless of the previous exposures to the two methods. Both ETC and EFR significantly reduced abdominal fat individually but not their combination. Free fatty acid levels significantly different in EFR and ETX+EFR but not in ETC birds. Differential leukocyte count and H/L ratio did not vary except in study 3, where in a higher heterophil and lower lymphocyte count in ETC birds resulted to a higher H/L ratio while monocyte values were highest in ETC and EFR birds and lowest in the untreated groups. No significant difference was observed in mortality rate.

Document Type

Dissertation

Degree

Doctor of Philosophy in Animal Science

College

Graduate School (GS)

Adviser/Committee Chair

Severino S. Capitan

Committee Member

Severino S. Capitan, Carmelita M. Rebancos, Cesar C. Sevilla, Renato SA. Vega

Language

English

LC Subject

Broilers (Chickens), Chickens, Animal science Animal and Dairy Science Cluster

Call Number

LG 996 2011 A5 N33

This document is currently not available here.

Share

COinS