Bem-estar e comportamento de fêmeas bubalinas da raça Murrah, em sistemas tradicional e silvipastoril, em Belém, Pará

Abstract

This study aims to assess the welfare and behavior of Murrah buffalo heifers reared on pasture Brachiariahumidicola in Traditional and Silvopastoral systems, in Belem, Para State, Brazil, to develop environmental management strategies, based on the thermal comfort of this species. The experiment was conducted at Embrapa Eastern Amazon, in its Research Unit Animal "Senator Alvaro Adolfo" in Afi type climate, according Köppen. The animals were placed in the Traditional System (TS, n = 10), composed of three paddocks, without access to water for bathing and shading and SilvopastoralSystem (SPS, n = 10), shading the forest species Racospermamangium. The experimental period for the collection of physiological parameters and meteorological indices were calculated, the farming systems was twelve months, divided into three experimental periods: Rainier (January-April), transition (from May to July) and less rainy (August to December), in two shifts (morning and afternoon). For the evaluation of animal behavior experiment was conducted for four months in the less rainy season, between August and November 2009. To perform the evaluation activities, were considered three different periods of the day: Period of the morning - between 6: 00 am and 9:55 am, Intermediate Period - 10:00 am and 1:55 pm, and Afternoon - 2:00 pm and5:55 pm, were also measured meteorological variables temperature and relative humidity. In animal behavior, grazing, ruminating and resting time, in both standing up and lying, and the SSP in non-shaded and shaded. Data were compared by t test (P <0.05). The average air temperature during the year were, respectively, 28.72ºC and 27.71ºC in TS and SPS. The values of relative humidity in the experimental period of twelve months was between 73.08% and 99.09%. The RT (38.15 ± 0.19°C to 38.84 ± 0.39°C) and CF (54.59 ± 7.73 beats/minuteto 73,86±8,49 beats/minute) were above the range of variation normal buffaloes. The RF in the afternoon for two systems were above the levels considered normal for buffalo, with an amplitude of 32.63 ± 6.21 movements/minute to 34.60 ± 7.39 movements/minute. The THI values were elevated in both farming systems, and were between 76.27 and 86.73, above the comfort level of buffaloes. The BCI, in TS, were in the range of 2.25 ± 0.18 to 2.50 ± 0.32 and the SPS were between 2.22 ± 0.19 to 2.41 ± 0.27 (P> 0.05) . In both systems, the activities of animal behavior were reduced in the intermediate period, except idling. Grazing and ruminating time in the morning, and idling activity, standing up, during the intermediate period, were higher in TS. The heifers remained longer period of time (P <0.05), standing up in the TS. In SPS, air temperatures were higher in the shade effect, all activities were reduced in the intermediate period, except idling. Grazing and ruminating time, in the morning, were higher in unshaded areas of the SPS and idling, standing up, during the intermediate period, in the shaded areas. Under the experimental conditions the buffalo heifers spent more time grazing in milder hours of the day as a way to avoid the damaging effects of the high incidence of solar radiation and high air temperatures, on the humid tropics of the Amazon. Thus, SPS can contribute to animal welfare and increase their productive behavior.