Avaliação do comportamento e do bem-estar de vacas criadas em sistema compost barn em condições tropicais

Abstract

The behavior of dairy cattle can be affected by the type of housing system in which they are raised. The compost barn system for dairy cattle was developed to improve animal comfort, health and longevity, as well as to facilitate handling practices. The aim of this study was to characterize the behavior of cows in a compost barn in tropical climate. Thirty-three lactating cows were monitored in the winter period and 31 in the summer period. In a second property, the behaviors of 40 lactating cows (20 primiparous and 20 multiparous) during the winter period were monitored. . Records of behaviors were taken every 15 minutes for a total 48 hours, with interruptions in the milking periods and at stirring up bed. The recorded behaviors were: standing up ruminating, standing in idleness, standing up eating, lying down in idleness or lying down ruminating. During the summer period, the animals' average resting time was similar to the one expected for high production cows. In addition to evaluating the behavior of the animals, we recorded the locomotion score, dirt score, and temperature/relative humidity of the air inside the barn for further calculation of the temperature and humidity index (THI). Simple and multiple linear regression analyzes were performed to evaluate the relationship between each of the behavioral responses and the possible explanatory variables. Subsequently, the variables were submitted to analysis of variance, with a comparison of the means Tukey test and SNK at a significance level of 5%. Descriptive analyzes were used to characterize the direct visual observations of the behaviors providing averages in hours/ day. The bioclimatological data of the environment (temperature, relative humidity and temperature and THI) were expressed in averages, as well as the bed surface temperature of CB. Locomotion, dirt and body condition scores were presented as percentages, in the first two of which were quantitatively by chi-square distribution. The bioclimate within the CB system on the farm 1 was close to the external environment. The mean THI on the days of the survey did’t exceed 74, and in a large part of the evaluation period the animals were submitted to an environment without thermal stress. The predominant locomotion score in both farms was score 0 (normal) and score 2 (mild claudication), there were no animals with score 3 (severe claudication). Similarly in both properties the behavior of the animals was influenced by the management of the property and mainly by the feeding. The animals were fee d from 3 to 6 h / day, the rumination activity was from 6 to 8 h / day and the behavior of lying down was from 10 to 12 h / day. These are the main behaviors that indicate the degree of comfort in which the animals are submitted. In view of these results, we can infer that lactating cows housed in a CB system in tropical climate presented a natural behavior consistent with a s tate of comfort. The animals' soiling score was high, indicating the need for producers to pay greater attention to the correct management of the compound to further improve the comfort and welfare of the animals raised in this system.