COMPETITION FOR FOOD IN THE TROUGH AND THE RELATIONSHIP WITH FEED
EFFICIENCY
Désirée R. Soares1, Karen S. Schwartzkopf-Genswein2, Joslaine N.S.G. Cyrilo3, and
Mateus J.R. Paranhos da Costa4
1Programa de Pós-Graduação em Zootecnia, Faculdade de Ciências Agrárias e
Veterinárias, UNESP, 14.884-900, Jaboticabal-SP, Brazil. CNPq PhD scholarship
2 Agriculture and Agri–Food Canada, Lethbridge Research Centre, Lethbridge, Alberta,
Canada.
3 Centro Avançado de Pesquisa Tecnológica do Agronegócio de Bovinos de Corte,
Instituto de Zootecnia, Sertãozinho-SP, Brazil.
4 Departamento de Zootecnia, Faculdade de Ciências Agrárias e Veterinárias, UNESP,
14.884-900, Jaboticabal-SP, Brazil. Pesquisador CNPq.
Désirée Soares
[email protected]
The aim of this study was to address the association between aggressive behaviour,
feed efficiency and weight gain in feedlot cattle. Sixty-four Nellore heifers (all pregnant)
with 525.5 + 36.7 days of age average, were housed in a pen of feedlot (41m2/animal),
with eight troughs equipped with radio frequency (GrowSafe® System Ltd., Airdrie, AB,
Canada) to calculate the residual feed intake (RFI, kg/d). The diet was offered ad
libitum, three times a day consisting of corn silage, ground corn, soybean meal and
mineral supplement. Heifers were weighed every 28 days to calculate the average daily
weight gains for each individual (ADG, kg/animal). Aggressive behaviour (AGR) was
assessed during 16 d non-consecutive (0700 to 1800) using continuous recording and
behaviour sampling method. The frequencies of displacement (DISP, when there is
physical contact among to animals, and the actor pushes his head, horn or body,
resulting in the displacement of the receptor). The Pearson’s correlation coefficients
were estimated for all variables. There were significant positive correlations (P < 0.05)
between AGR and RFI (r = 0.35), but not (P > 0.05) between ADG with RFI (r = 0.01)
and AGR (r = 0.02). Based on these results we conclude that cattle with greater
aggressive behaviour were less feed efficient, however this did not affect their weight
gain in feedlot. Financial support: CNPq (Process number: 148704/2011-5).
4TH INTERNATIONAL SYMPOSIUM ON BEEF CATTLE WELFARE
Iowa State University ~ Ames, Iowa
July 16-18, 2014