Temperature, thermal comfort, and animal ingestion behavior in a silvopastoral system

Abstract

Thermal discomfort is one of the main causes of production losses in animals fully exposed to solar radiation under extensive livestock farming. The inclusion of trees in this farming system is the most efficient strategy to decrease the temperature and increase animal productivity without the need to explore new areas. In this context, the objective of this study was to characterize the microclimate in a silvopastoral system (SPS), a refuge area, and an open pasture, and evaluate thermal comfort and the ingestive behavior of animals under shade. The study was conducted at the Agronomic Institute of Paraná (IAPAR), located in Ibiporã, Paraná state, Brazil, in three areas with distinct management systems: a SPS of Eucalyptus grandis with Tifton 85 (Cynodon spp.), a woodland of Leucena leucocephala that provided shade to cattle, and a pasture in full sun (PFS). Automatic meteorological stations were installed in the SPS (one station beside the tree lines and the other in an average distance perpendicular to the rows), one in the refuge area, and one in the PFS. The measured variables were air temperature and relative humidity. The mean temperatures of the shaded treatments were compared to those of the PFS using a t-test. The mean values of the temperature and humidity index (THI) were calculated for each season of the year. The animal ingestion behavior in the SPS was analyzed in three typical days in different seasons of the year. Significant differences were observed between shade treatments and full-sun pasture, with a temperature decrease ranging from 0.4 to 1.6 °C in the shaded systems. The comparison of animal thermal comfort between the study areas in different seasons of the year indicated that there were no significant differences in thermal comfort between the SPS and refuge area relative to the PFS, suggesting a need to monitor the animals’ body temperature to better estimate thermal comfort. The evaluation of the ingestive behavior evidenced the animals’ preference to perform activities under tree shade and that the SPS led to changes in their food habits, optimizing grazing time. Therefore, the trees directly affected the microclimate of the studied environments, attenuating the temperature, protecting the animals against direct solar radiation, and providing better thermal comfort.

Could cattle ranching and soybean cultivation be sustainable? A systematic review and a meta-analysis for the Amazon

“…This result suggests that herbage biomass is not always a good predictor, as for example the thermal comfort (shade) provided by trees, or food production provided by woody species, may be relevant Could cattle ranching and soybean cultivation be sustainable? for livestock productivity (Junior et al 2019). A similar trend was found in the European meta-analysis, with a negative relationship detected for biomass production, while food production was positively affected by agroforestry (Torralba et al 2016).…”

Characterization of Thermal Patterns Using Infrared Thermography and Thermolytic Responses of Cattle Reared in Three Different Systems during the Transition Period in the Eastern Amazon, Brazil

“…These results are in line with the scientific literature that highlights the importance of shading in silvopastoral systems to reduce heat stress in cattle. The presence of trees in silvopastoral systems provides shading, which reduces direct exposure to solar radiation and helps to reduce the accumulation of heat in the environment [51,[54][55][56][57][58][59]. In addition, the presence of bathing areas, as in the integrated system, can also contribute to heat dissipation by the animals.…”

Characterization of the Temperament and Reactivity of Nelore Cattle (Bos indicus) Associated with Behavior Scores during Corral Management in the Humid Tropics

“…RR values are reported above the basal rate at 60 respiratory incursions per minute, for each degree above the temperature of 21.3 °C [ 54 , 55 , 56 ]. On the other hand, in the evaluation of BST, it was evidenced that the head region presented a higher temperature when compared to other regions of the body, due to the greater blood supply in this region [ 57 , 58 , 59 ].…”