Behavior and thermal comfort of light and dark coat dairy cows in the Eastern Amazon

Welligton Conceição da Silva; Éder Bruno Rebelo da Silva; Maria Roseane Pereira Dos Santos; Raimundo Nonato Colares Camargo Junior; Antônio Vinicius Corrêa Barbosa; Jamile Andréa Rodrigues da Silva; Juliana Amaral Vinhote; Eudilene Dalet Vitor de Sousa; José de Brito Lourenço Júnior

doi:10.3389/fvets.2022.1006093

Behavior and thermal comfort of light and dark coat dairy cows in the Eastern Amazon

Front Vet Sci. 2022 Sep 14:9:1006093. doi: 10.3389/fvets.2022.1006093. eCollection 2022.

Authors

Welligton Conceição da Silva¹, Éder Bruno Rebelo da Silva², Maria Roseane Pereira Dos Santos³, Raimundo Nonato Colares Camargo Junior⁴, Antônio Vinicius Corrêa Barbosa⁵, Jamile Andréa Rodrigues da Silva¹, Juliana Amaral Vinhote⁶, Eudilene Dalet Vitor de Sousa¹, José de Brito Lourenço Júnior⁷

Affiliations

¹ Institute of Animal Health and Production, Federal Rural University of the Amazon, Belem, Pará, Brazil.
² Institute of Agronomy, Federal Rural University of the Amazon, Capanema, Pará, Brazil.
³ Institute of Engineering and Geosciences, Federal University of Western Pará, Belem, Pará, Brazil.
⁴ Institute of Animal Science, Federal Institute of Education, Science and Technology of Pará, Santarém, Pará, Brazil.
⁵ Cyberspace Institute, Federal Rural University of the Amazon, Belem, Pará, Brazil.
⁶ Institute of Agronomy, Lutheran University Center of Santarém, Santarém, Pará, Brazil.
⁷ Institute of Veterinary Medicine, Federal University of Pará, Belém, Pará, Brazil.

Abstract

This study aimed to evaluate the behavior and thermal comfort of 20 Girolando cows (5/8-H/G), with light and dark coats, in the wettest period of the year, in Santarém, Pará, Brazil, in pasture with access to shade, and plenty of drinking water and mineral salt. Animal behavior categories were computed for 12 h a day, on 3 days in a row, by trained observers. Three day shifts were considered: Morning (6:00 a.m. to 9:55 a.m.), Intermediate (10:00 a.m. to 01:55 p.m.) and Afternoon (2:00 p.m. to 05:55 p.m.). The Temperature Index (TI), the Black Globe Humidity Index (BGHI) and the Comfort Index (CI) were calculated to measure thermal comfort. At all times studied, BGHI pointed that the environment was outside the thermal comfort zone. Dark-coated animals spent more 34.26% of the time in activities in the shade. The light-coated animals remained more 11.88% of the time in the sun, performing their natural behaviors. Both light and dark coat animals remained more 77 and 74.44% of the time in the sun, respectively. The behavior "in the sun while grazing" was the most evident, in both coats, in the studied shifts. The behaviors "in the shade while walking" and "in the shade while standing idle" were more evident (p < 0.01) in dark-coated cattle. The grazing behavior was higher in animals with dark coat (p < 0.05). In all evaluated shifts, there was a positive correlation between the behavior "in the sun while grazing" with the CI (r = 0.44211; p < 0.0305). Behaviors performed in the shade, such as "idleness while lying down," "ruminating while lying down and standing up," and behaviors "in the sun," "idleness while lying down" and "ruminating while lying down," were negatively correlated with CI. It is concluded that, even in the wettest period of the year, in the Eastern Amazon, Girolando dairy cows are exposed to hot environments, which causes thermal discomfort and changes in their natural behavior, as they spend more time standing in shaded areas, usually in rumination. Also, light-coated cows spend more time in the sun, while dark-coated cows spend more time in the shade. Thus, light-coated cows tend to have health and zootechnical performance negatively affected.

Keywords: Girolando; bioclimatology; ethology; heat; stress.