Cattle in integrated system with forests seek less water
Cattle in integrated system with forests seek less water
Results of research involving bovine behavior have revealed that animals bred in integrated systems with trees drink from water troughs less often in comparison with conventional systems, in full sun. The reduction nears 19%, according to a study developed at Embrapa Southeastern Livestock. This is one of the advantages of integrated crop-livestock-forestry (ICLF) production systems, which have been gradually adopted in the country, having reached almost 12 million hectares.
This and other advantages of the ICLF production strategy are reported by the researcher Alexandre Rossetto Garcia, who works with animal reproduction biotechnology. He is a member of a multidisciplinary team that has been comparing cattle breeding in integrated and conventional systems.
Rossetto advised Alessandro Giro's Master's dissertation from the Federal University of Pará (UFPA). Giro is a veterinarian who developed the study on the thermal comfort of bovines raised in ICLFS. During the research, the behavior of the animals and the frequency they went to water troughs and mineral salt feeders were also assessed. Water consumption was not directly measured in terms of volume. The fieldwork was conducted from January to June 2017 and the dissertation was defended in July 2018.
The work took place through visual observation in monthly runs of two consecutive days, in the course of eight hours per day. The team stayed at a distance that did not interfere with the animals' behavior. The study showed that, in the afternoon, 87% of the animals that were exposed to the sun went to the water trough. In the shaded area, this indicator dropped to 63% in the same period. The difference was higher in the months from January to March, when temperatures are generally higher.
ICLF systems optimize natural resources
“In the ICLFS area, where there are trees, we also tried to observe if the animals sought the shaded spaces or the sun more. We measured the length of time that they remained in the sun and in the shade in minutes. We had evidence that they prefer the shade, regardless of the time of day”, Alessandro stated. The animals that had the choice between the sun and the shade spent more time grazing, either idly or ruminating under the trees.
Animals that suffer heat stress reduce their food intake. “When they take shelter in the shade, the thermal load on the animals decreases and there is less need to dissipate the heat into the environment. This reduces panting and perspiration, minimizing the demand for water ingestion”, Rossetto explains.
When they need to dissipate heat, the animals spend energy in processes that are not related to the production of milk and meat and to reproduction. According to the Embrapa researcher, ICLFS allows a more intelligent use of natural resources. The shading reduces ambient temperature by up to 5ºC, which is excellent for the animal's thermal comfort and well-being.
Precision in cattle monitoring
Rossetto also explains that the variation of 0.5ºC in the animals' internal temperature is rather expressive. The thermographs used to measure the bovines' surface temperatures are very precise, to the extent of measuring hundredths of degrees. According to him, two factors influence animal welfare: the microclimate (set of information that can be assessed with the help of weather stations) and individuals' thermal conditions in those areas.
In more recent studies, other equipment has helped science with data to monitor cattle. Embrapa Southeastern Cattle can also obtain information on animal behavior thanks to adaptations of techniques available in the market. Researchers have worked in precision cattle-farming projects, using a computerized system that identifies movement, idleness and rumination from collars with connected sensors.
In order to have the equipment work in pasture areas for beef cattle, including in ICLFS, it was necessary to install antennas to broadcast the wireless signals and solar energy panels to feed the system. The solar panels to capture energy were developed by the research center as a way to reduce costs and to make the use of the equipment in the fields possible. Originally, the private company that produced the computerized system aimed the equipment to monitor dairy cattle, which has more predictable daily movements, such as the time for milking.
According to Edilson da Silva Guimarães, supervisor of Information Technology, Embrapa Southeastern Livestock indicated adaptations for the communication and energy systems to the company. “Data transmission takes place from one antenna to the other, as if it was a mesh. We suggested that they changed the type of antenna to improve communication between them”, he affirmed. The data collected by the sensors are centralized and can be accessed from a distance, in computers. Such equipment was purchased with funds from the Ministry of Agriculture, Livestock and Food Supply (Mapa) with a counterpart from Embrapa.
The work assessed the behavior of beef cows in pastures without trees with the wireless monitoring system and was presented at the III International Workshop of Precision Ambiance, in 2017, in Campinas.
Multidisciplinary research
In ICLFS, the multidisciplinary team at Embrapa Southeastern Livestock studies not only animal behavior, but also forage availability and quality, soil fertility, the development of the tree component, agricultural productivity, performance and reproductive efficiency of the animal component, as well as methane emissions and soil microbiota.
According to Rossetto, bovine behavior is very closely related to the interaction between them and their space. Questions like “do the animals benefit from the shade? ” and “at what times of the day do they prefer the shaded areas?” help science better understand the differences between the integrated systems with trees and cattle-raising exclusively in the sun.
Thermal comfort and reproductive capacity
Bovine fertility can also be affected by exposure to high temperatures and to intense solar radiation. Whenever dairy or beef cattle's body temperature increases, a series of negative consequences unfolds. When an animal feels discomfort due to the heat, it starts to produce a higher amount of cortisol, a hormone directly related to stress. According to Rossetto, an increased concentration of this hormone makes the animals feed less, which significantly harms production. In a beef animal, there is less growth and thus less productivity.
From a reproductive point of view, high thermal body indicators represent damages to the farmer. For example, when the body temperature of a bull increases, the internal temperature of the testiculs also goes up. This causes lower semen quality. In the females, the process is similar. When their internal temperature increases, the oocytes produced are of low quality, which often hinders fertilization.
If it occurs, the embryo requires favorable conditions for its development and an ideal temperature is one of them. The fetus is highly sensitive to thermal oscillations and can even die precociously, before the professionals who follow the gestation even notice it. Moreover, in situations when there is stress during the gestational stage, the development and the functionality of the placenta are harmed and the fetus can be malformed.
The research on thermal comfort and reproductive efficiency was made with heifers and female beef adults in a project funded by the São Paulo State Research Support Foundation (Fapesp). Rossetto is planning on continuing this line of research with males at a reproductive age.
Translation: Mariana Medeiros
Ana Maio (MTb 21.928/SP)
Embrapa Southeastern Livestock
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