Ganho de peso de bovinos confinados em ambiente sombreado: Revisão de Literatura

Abstract

The general consumption of food is directly linked to the world's socioeconomic development. When it comes to bovine production systems, three models are the most cited, extensive, semi-intensive and intensive, or known as confinement. Animal welfare in these systems has been preserved as an important point in animal production. Factors called stressors are those that place the body in situations of danger. Faced with moments of stress, physical and mental responses are activated in order to maintain the body's balance. When stress is generated, direct losses occur, mainly due to a drop in food intake. Living beings can be divided into ectoderms and endotherms. Ruminants are endothermic animals and have some forms of temperature control, which can be evaporative through sweating, respiration and heat loss through excreta (feces and urine) and non-evaporative which are conduction, convection and radiation. In feedlots, heat stress generates a negative result in the degree of carcass finishing due to compromised animal welfare, reducing daily gains due to reduced food consumption. The shading used in beef cattle raising has been studied by several authors. The main advantage of using shading is the reduction of solar radiation on these animals and a higher productivity. Shade can be generated naturally by trees, and it is a great option to be used in properties, because it promotes thermal comfort to the animals. When it comes to artificial shading, the best known is the nylon screen, or the commercial name sombrite, which provides thermal comfort for confined animals. Galvanized steel tiles are also recommended, and white paint is indicated on the outside, promoting better reflection of solar radiation. Zinc and fiber cement roof tiles should only be used as a last resort, and with high ceilings, as they absorb the sun's rays and have little reflectivity, providing the animals with little thermal comfort. Artificial shading acts to protect the sun's rays, reducing thermal stress and increasing the productivity of confined cattle.