Effects of differents temperatures upon european steers. I. Respiratory frequency and rectal temperatures

Abstract

Twelve crossbred Holstein castrated male steers, with 2 years old, were used in a factorial arrangement 2 x 2, in a change-over design, comparing 4 treatments: A) outdoors plus roughage feed; B) outdoors plus roughage feed plus concentrate meal; C) climatic chamber plus roughage feed; D) climatic chamber plus roughage feed plus concentrate meal. The steers in cand D stayed in the chamber 23h a day at 32°C and 86% relative-humidity. They presented higher rectal temperatures and higher respiratory frequencies than the outdoor-ones. Considering only C and D treatments, D caused higher rectal temperatures than C.