ABSTRACT In the swine intensive farming, one of the biggest problems is to meet the thermal requirements of piglets in heated creeps, which demand high consumption of electricity and increase in production costs. The aim of this study was to evaluate the thermal efficiency and the consumption of electric energy in heated and internal insulated creeps, made of recycled material, when compared to creeps without thermal insulation. The treatments were: control (TCON): creep heated through suspended electric resistance, controlled by thermostat; thermal insulation with recycled material (TPK). The experiment was carried out for 21 days. In the treatments, the temperature (°C) and relative humidity (RH) of the air, consumption of electric energy (kWh), specific consumption (kWh kg-1), specific cost (R$ kg-1), weight gain (kg) and daily weight gain (kg day-1) were measured. The indoor insulation creep kept the upper air temperature (33.05°C) to the control treatment without thermal insulation (32.6°C) and was more efficient in the use of electric energy (2.46 kWh) in comparison to the non-insulated creep (3.48 kWh). The heat-insulated creep shelter consumed the equivalent of 1.02 kWh more than the insulation treatment to maintain the thermal comfort condition of piglets between 30 and 34 ° C. The conclusion is that the use of recycled material as thermal insulation in heated creeps reduces heat losses and economy electricity.

O uso racional de energia elétrica em creches suínas pode ser viabilizado sem afetar o desempenho produtivo dos animais visando à sustentabilidade do setor razão por que o objetivo deste trabalho foi avaliar a eficiência de duas tecnologias de controle de temperatura em sistema de aquecimento resistivo em creche suína, no uso de energia elétrica e no ganho de peso dos leitões. Os sistemas avaliados foram: resistências elétricas suspensas com controle PID (proporcional, integral e derivativo) e resistências elétricas suspensas com termostato. O experimento foi realizado durante o período de inverno, entre maio e setembro de 2013. Os critérios de comparação foram: consumo de energia elétrica (kWh), consumo específico (kWh kg-1), custo específico (R$ kg-1), indicador de eficiência elétrica no aquecimento, ganho de peso (kg) e ganho de peso diário (kg d-1). O sistema de aquecimento com controlador PID, apesar de apresentar maior consumo médio, foi mais eficiente quanto ao uso de energia elétrica para produzir 1 kg de peso vivo (2,88 kWh kg-1), quanto ao custo específico (0,75 R$ kg-1) e quanto ao ganho de peso dos leitões (7,3 kg) em comparação com o sistema com termostato (3,98 kWh kg-1, 1,03 R$ kg-1 e 5,2 kg, respectivamente).

The rational use of energy in swine nurseries can be made possible without affecting the productive performance of animals, aiming the sustainability of the sector. The objective of this study was to evaluate the efficiency of two technologies for temperature control of resistive heating system for swine nursery on the use of electricity by the systems and on the weight gain of the piglets. The evaluated systems were: overhead electric heaters with PID (proportional, integral and derivative) control and suspended electric heaters with thermostat. The experiment was conducted during the winter period between May and September 2013. The comparison criteria were: electricity consumption (kWh), specific consumption (kWh kg-1), specific cost (R$ kg-1), indicator of electrical efficiency in heating, weight gain (kg) and daily weight gain (kg d-1). The heating system with PID controller, although showed a higher average consumption, was more efficient as the electricity used to produce 1 kg of body weight (2,88 kWh kg-1), as the specific cost (0,75 R$ kg-1) and for weight gain of piglets (7,3 kg) compared to the system with thermostat (3,98 kWh kg-1, 1,03 R$ kg-1 and 5,2 kg, respectively).