Welfare traits of Bos indicus cattle immunologically castrated and fed beta-adrenergic agonists

Martello, Luciane Silva; Antonelo, Daniel Silva; Consolo, Nara Regina Brandao; Pacheco, Verônica Madeiro; Negrão, João Alberto; Rosa, Alessandra Fernandes; Leme, Paulo Roberto; Sousa, Rafael Vieira; Silva, Saulo Luz

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Anim Biosci > Accepted Articles

Article

DOI: https://doi.org/10.5713/ajas.19.0986 [Accepted] Published online April 12, 2020.

Welfare traits of Bos indicus cattle immunologically castrated and fed beta-adrenergic agonists

Luciane Silva Martello^1,*

, Daniel Silva Antonelo¹

, Nara Regina Brandao Consolo¹

, Verônica Madeiro Pacheco¹

, João Alberto Negrão¹

, Alessandra Fernandes Rosa¹

, Paulo Roberto Leme¹

, Rafael Vieira Sousa¹

, Saulo Luz Silva¹

College of Animal Science and Food Engineering, University of São Paulo, Pirassununga 13635900, Brazil

Correspondence: Luciane Silva Martello, Tel: +55-19 3565 6732, Fax: +55-19 3565 6732, Email: martello@usp.br

Received: 27 December 2019 • Revised: 23 January 2020 • Accepted: 17 March 2020

Abstract

Objective
This work was carried out to evaluate the effects of zilpaterol hydrochloride (ZH) and ractopamine hydrochloride (RH) combined with immunocastration on the welfare traits of feedlot Nellore cattle.
Methods
Ninety-six Nellore males (average BW = 409 ± 50 kg; average 20 mo of age) were divided into two groups according to BW; half of the animals in each group received two doses of an immunocastration (ImC) vaccine in a 30 day interval, and the other half did not receive the vaccine (NoC). Afterward, the animals were housed and fed a common diet for 70 days. Then, they were split into three groups and fed one of the following diets for 30 additional days: control (CO) diet, with no β-AA; ZH diet, containing 80 mg/day ZH; and RH diet, containing 300 mg/day RH. Welfare traits were assessed by monitoring body surface temperature using infrared thermography images (IRT) and plasma cortisol and temperament measurements.
Results
There was no interaction between sexual condition and diet for any trait. The ImC and NoC groups did not differ in rectal and ocular temperatures. The ImC animals had higher flight speeds (P=0.022) and tended to have higher cortisol levels (P= 0.059) than the NoC animals. Animals fed ZH and RH did not differ in cortisol levels, respiratory rate, rectal temperature, temperature measured by IRT, or temperament behaviour.
Conclusion
The ImC animals showed a less stable temperament during handling practices than NoC, whereas ZH and RH supplementation had no adverse effects on animal welfare.

Keywords: Cattle Behaviour; Bos indicus Temperament; Infrared Thermography; Ractopamine Hydrochloride; Zilpaterol Hydrochloride