1 research outputs found
Reactivity of Nellore steers in two feedlot housing systems and its relationship with plasmatic cortisol
To evaluate reactivity to assess the temperament of Nellore steers in two feedlot housing
systems (group pen or individual pen) and its relationship with plasmatic cortisol, 36
experimental units were observed five times at 28-day intervals of weight management during
a 112-day feedlot confinement. A reactivity score scale ranging from 1 to 5 was applied when
an animal was in the chute system. To the calmest animal, a reactivity score of 1 was ascribed
and to the most agitated, 5. Blood samples were collected for cortisol analysis. No differences
were found in reactivity and feedlot system. There was a relationship noted between reactivity
and feedlot time in both housing systems (Pb0.01). There was a relation between reactivity
and cortisol levels for group animals (P=0.0616) and for individual ones (Pb0.01). Cortisol
levels varied among housing systems (Pb0.01). Feedlot time influenced the cortisol levels
(Pb0.09 individual; Pb0.01 group) and when variable time was included, these levels changed,
decreasing in the group pen and increasing in individual pens. The continuous handling
reduces reactivity and plasmatic cortisol, and group pen system seems to be less stressfully
than individual pens