Federal University of Technology - Parana (UTFPR), Dois Vizinhos Campus, Estrada para Boa Esperança, km 04, Dois Vizinhos, PR, 85660-000, Brazil.
Federal University of Fronteira Sul (UFFS), Realeza Campus, Realeza, PR, Brazil.
Trop Anim Health Prod. 2021 Mar 19;53(2):213. doi: 10.1007/s11250-021-02648-9.
The aim of this study was to evaluate the physiological response to heat stress and ingestive behavior of Jersey cows in silvopasture and conventional pasture grazing systems. The experiment was carried out during the warm season, spanning spring, summer, and fall seasons in the Brazilian subtropical climate zone. Twelve lactating Jersey cows were observed in rotational grazing on Cynodon nlemfuensis Vanderyst and Panicum maximum Jacq. Treatments were composed of different grazing systems (silvopasture and conventional pasture). The silvopasture grazing system had eucalyptus trees (Eucalyptus grandis Hill ex Maiden) with an average height of ≈ 10 m and row spacing of 20 m. In the conventional pasture grazing system, there were no rows of eucalyptus and no other type of tree or structure to provide shade to the animals. During the summer and fall periods of evaluation, the silvopasture animals presented a lower respiratory rate, whereas during the spring and fall evaluation periods, these animals presented a lower rectal temperature. Cattle in the silvopasture showed longer grazing times at night (+21.65 min) and overall (+36.00 min) and remained lying down (ruminating and resting) for longer (+ 73.07 min) than conventional pasture grazing system animals. In addition, the animals in the silvopasture had a lower water intake (3.12 L/100 kg BW). The silvopasture grazing system improved the welfare of the grazing Jersey cows, as evidenced by the improvement in physiological response to heat stress, increased grazing time and decreased standing time (resting + ruminanting) when compared to cows in the conventional pasture grazing system.
本研究旨在评估热应激下泽西奶牛在林牧和传统放牧系统中的生理反应和摄食行为。实验在巴西亚热带气候区温暖季节进行，跨越春季、夏季和秋季。12 头泌乳泽西奶牛在斑茅和宽叶雀稗轮牧，采用旋转放牧。处理由不同的放牧系统（林牧和传统放牧）组成。林牧放牧系统有桉树（Eucalyptus grandis Hill ex Maiden），平均高度约为 10 米，行距为 20 米。在传统放牧系统中，没有桉树行，也没有其他类型的树木或结构为动物提供遮荫。在夏季和秋季评估期间，林牧动物的呼吸率较低，而在春季和秋季评估期间，这些动物的直肠温度较低。林牧动物的夜间（+21.65 分钟）和整体（+36.00 分钟）放牧时间更长，且躺卧时间（反刍和休息）更长（+73.07 分钟），比传统放牧系统动物更长。此外，林牧动物的饮水量较低（3.12 L/100 kg BW）。与传统放牧系统的奶牛相比，林牧放牧系统改善了放牧泽西奶牛的福利，这体现在对热应激的生理反应改善、放牧时间增加和站立时间（休息+反刍）减少。
