Resumo

LARIOS-CUETO, Silvia et al. Stress indicators in cattle in response to loading, transport and unloading practices. Rev. mex. de cienc. pecuarias [online]. 2019, vol.10, n.4, pp.885-902.  Epub 30-Abr-2020. ISSN 2448-6698.  https://doi.org/10.22319/rmcp.v10i4.4561.

Transporting of cattle can cause multiple physical and psychological stressors that may affect profitability. An evaluation was done of the effects of stress produced by management practices before, during and after cattle transport, based on changes in physiological indicators and weight prior to the finishing stage. Animals were 124 weaned calves transported to the State of Mexico from the states of Veracruz (500 km) and Chiapas (851 km), Mexico, for finishing in feedlots. Four treatments were used: 1) preloading reception management at place of origin (PRE); 2) PRE + preloading application of a β-blocker (PREβ); 3) reception management upon unloading at feedlot (POST); and 4) POST + preloading application of a β-blocker (POSTβ). The data were analyzed with the GLM procedure in the SAS program. The experimental design was a completely random 2 x 4 factorial arrangement (two transport distances and four treatments). Average live weight (LW) decreased 42 kg per animal (11.3 %) at unloading, but 10 days after unloading had recovered by 35 kg. Live weight loss was lower in the PREβ treatment (37.6 kg) than in the PRE (47.5 kg) or POSTβ (44.5 kg) treatments. The PREβ did not differ (P>0.05) from the MD (38.7 kg). The most important stress indicators were changes in live weight, glucose and cortisol, with differences (P<0.05) identified by treatment and transport distance. No differences (P>0.05) were present in the other indicators (free fatty acids, β-hydroxybutyrate, total proteins, and sodium and potassium concentrations). The combination of preloading reception management and a β-blocker produced the least amount of stress in the animals. More attention is needed on the period between loading and unloading cattle for transport to finishing to establish optimum conditions.

Palavras-chave : Cortisol; Carazolol; Finishing; Transport.