Energy Savings in Swine Production Through the Use of Energy Efficient Lighting and Heat Lamps

Grant # 94-02-01
Principal Investigator: Hongwei Xin
Co-Principal Investigator: Dwaine S. Bundy
Organization: Iowa State University, Agricultural and Biosystems Engineering
Student Support: One graduate (100% effort) and one undergraduate (part-time)
Project Dates: 7/1/94 – 6/30/97
Technical Area: Energy Efficiency


Background and Significance:
Iowa swine producers use about $24 million worth of electric energy per year in providing supplemental heat to baby pigs. Infrared 250W heat lamps had been the conventional heat source. The first two-year results of our IEC project showed that replacement of the conventional 250W heat lamps with energy-efficient 175W radiant heat lamps could yield the following economic benefits for the producer:

A $36 savings per heat lamp in annual energy use (@ $0.10/kWh), or $5,500 savings for a 1,000-sow farrowing operation. Additional savings may result from reduced peak load demand. A 1.2% absolute reduction in piglet mortality, or 300 extra pigs weaned per 1,000 sows per year. A 45% reduction in heat lamp breakage and thus replacement labor cost. Improved resting pattern of the piglets under the heat lamp. Same rate of body weight gain for the piglets.

The study also revealed that heat lamp use (HLU) of the piglets was highly influenced by the time of the day, piglet age, and ambient temperature. Specifically, higher HLU was associated with daytime, younger pigs, lower-wattage heat lamp or lower ambient temperatures. The HLU behaviors clearly suggest that the piglets have variable thermal needs from birth to weaning. Constant heat sources during this vital period would be counterproductive to not only energy efficiency, but the piglet well- being. In fact, the higher piglet mortality for the 250W heat lamp was speculated to be contributed to its excessive heat and light intensity, which would force the piglets to spend more time huddling around the sow. Consequently, the piglets would be more susceptible to sow crushing. However, data from this study were insufficient to quantify the variable thermal needs of the piglets because (a) the HLU was measured at only 7 and 14 days of age, and (b) only fixed-output heat lamps were used. The data also could not differentiate the effects between light intensity and heat because only clear heat lamps were used.

Objectives of the Continuation Project:
To compare the effects of a variable heat lamp (175W to 100W) versus a fixed heat lamp (175W) on piglet behavior and performance at cool (65°F) and warm (80°F) ambient temperatures. The variable heat lamp is hypothesized to better meet the piglet thermal needs while using 21% less energy.

To evaluate the effects of light intensity/color of the heat lamps on piglet behavior and performance. Red-color heat lamps are hypothesized to be more attractive to piglets than clear-color heat lamps.

To develop and test a heat lamp controller that operates the heat lamps based on piglet age, ambient temperature, and presence of the piglets in the heated zone.

To educate swine producers on proper selection and operation of heat lamps and their controllers to improve energy efficiency and piglet performance.

An experimental farrowing room was set up at the ISU Swine Nutrition and Management Research Center (Fig. 2). It contains four custom-designed individual farrowing crates that allow for continuous measurement of piglet HLU. The electronic instruments for environmental control and measurement and monitoring of piglet behavior were acquired, fabricated, installed, and calibrated (Fig. 1).

As of December 1996, four trials have been conducted. One (summer) trial used the room temperature of 80±2°F and the other three (fall to winter) trials used 65±2°F. Table 1 summarizes the average responses.

A prototype, low-cost, operand heat lamp controller has also been designed and constructed. Evaluation of the on/off cycles of heat lamps on their life span has been in progress since November 1996.

Table 1. Heat lamp use (HLU), average daily gain (ADG), mortality, lamp failure rate, and electricity use as influenced by heat lamp output (variable vs. fixed) and color (clear vs. red). Mean and (SE).

lamp

room

No.

HLU

ADG

Mortality

Lamp

Energy use

Type*

Temp
(°F)

Trials

(%)

(g/day)

(%)

Failure

(kWh/
crt/d)

V-Red

80

1

7(-)

236(-)

16.7(-)

0.0(-)

3.3

65

3

59(4)

271(2)

3.3(3.3)

0.0(0.0)

3.3

V-Clear

80

1

6(-)

235(-)

9.1(-)

0.0(-)

3.3

65

3

58(2)

299(28)

10.4(5.8)

0.0(0.0)

3.3

F-Red

80

1

1(-)

217(-)

9.1(-)

0.0(-)

4.2

65

3

56(4)

269(12)

14(7)

0.3(0.3)

4.2

F-Clear

80

1

2(-)

235(-)

8.3(-)

0.0(-)

4.2

65

3

53(5)

272(16)

11.7(7.3)

0.0(0.0)

4.2

* V = variable output from 175W to 100W during the 21-day birth to wean period. F = fixed at 175W.

A prototype, low-cost, operand heat lamp controller has also been designed and constructed. Evaluation of the on/off cycles of heat lamps on their life span has been in progress since November 1996.

Additional Work:

  • One more trial for the cool temperature regime and 3 more trials for the warm temperature regime.
  • Development of heat lamp controller algorithms that integrate piglet age and ambient temperature.
  • Testing of the operand controller prototype with regard to its longevity, reliability, energy savings, and effects on piglet performance.
  • Integration of the operand controller and the control algorithms.
  • Field evaluation of the new controller. Dissemination of the research findings to swine producers and professionals locally and nationally.