Under conditions of high temperature, humidity, and incidence of solar radiation, dairy cows use behavioral changes as a strategy to decrease the metabolic heat production at pasture. The objective of this study was to evaluate the behavioral and physiological responses of Gyr and Girolando (5/8 Holstein 3/8 Gyr, and ½ Holstein ½ Gyr) dairy cows submitted to environments with and without shade. The experiment was conducted at Embrapa Cerrados (Technology Center for Dairy Zebu breeds—CTZL), Brasilia, Distrito Federal—Brazil, with 48 Gyr and Girolando cows total in the lactation group, with low to medium milk production, in full sun or shade with Eucalyptus urograndis (267 plants/ha⁻¹). The physiological and behavioral characteristics evaluated were panting score, superficial temperature, and time spent grazing, ruminating, and lying down. Other traits included skin and coat thickness, hair diameter, density and length, and predominant coat color. In addition, body measurements, such as body length, the height of withers, chest circumference, and shin circumference, were measured. Shaded cows had 34% longer rumination times than cows in full sun (p = 0.01). With a temperature-humidity index ranging from 79 to 83, the rumination time was 1.7 times higher in cows under shade (p = 0.01) during a 24-h period of observation. There were no significant differences in the grazing time between the environments, but lying time was 23% longer in cows under the sun (p = 0.01). The panting score was not influenced by the environment (p = 0.17). Girolando cows had a 35% higher panting score than Gyr cows (p = 0.01) regardless of the environment. The panting score increased two and a half times during the afternoon compared with the morning (p = 0.01). The surface and rectal core temperatures had significant differences between treatments and time of the day. Body measurements were not different between cows in both environments, but there was a difference between breeds. The use of trees in pastures with a silvopastoral system for dairy zebu cows is indicated to improve grazing behavior, as well as time spent ruminating and lying down.

Este trabalho teve como principal objetivo apresentar um método de zoneamento pedoclimático para o cultivo do milho consorciado com a braquiária que considere os componentes de risco climático, do potencial edáfico e de restrições territoriais. Com o uso de ferramentas de geoprocessamento, foram subtraídas do mapa base do estado, as unidades de conservação, os espelhos d´água, declividades superiores a 45% e as informações de solos não recomendadas para o desenvolvimento agrícola do Estado. O cálculo da reserva útil de água dos solos foi realizado a partir da reclassificação do mapa de solos em função da textura. As datas de semeadura com menor risco climático foram calculadas por meio do balanço hídrico das culturas. Da área total de Cerrado do estado de Goiás (329.581 km²), 50,13%, ou 165.218 km² não são considerados áreas agricultáveis, enquanto que 49,87%, ou 164.363 km², são agricultáveis. Essa abordagem permitiu identificar áreas mais apropriadas para o desenvolvimento agrícola do estado de Goiás e datas de semeadura com menor risco climático para a semeadura do consórcio. Esse estudo pode ajudar no desenvolvimento de políticas públicas que objetivem a sustentabilidade da agricultura a partir da adequação das datas de semeadura com menor risco climático das culturas com a proteção ambiental do Estado.