Lower Nighttime Temperatures Save Nearly $2/Pig

Research conducted at stations across the United States has documented a 29% reduction in the consumption of heating fuel in reduced nocturnal temperature (RNT) nursery rooms without any negative effects on pig performance. Average savings is about $1.71/pig leaving the nursery.

The study used swine nursery production facilities at the University of Minnesota, University of Missouri, Ohio State University and South Dakota State University.

Each location completed at least two replicate trials during winter and spring. Trials lasted 28 to 42 days.

One of two temperature treatments was imposed in two identical nursery rooms at each research station. In the control rooms (CON), temperature controllers were set at 86 °F for the first week, then reduced by 3.5 °F per week throughout the remainder of the trial. Day and night temperature settings were the same in CON rooms.

In the RNT rooms, temperature controllers were set at 86 °F for the first four days after pig placement. At Day 5, daytime temperatures were set to equal temperatures in the CON rooms, but ventilation controllers were set to reduce nighttime temperatures by 15 °F from 7 p.m. to 7 a.m. Daytime temperatures in the RNT rooms were also reduced by 3.5 °F per week during the remainder of the study.

Each room was independently monitored for consumption of heating fuel (propane or natural gas) and electricity. Rooms were assigned randomly to experimental treatments and pigs were assigned randomly to rooms.

As Table 1 shows, neither final pig weight, average daily gain, average daily feed intake nor efficiency of gain was different for pigs housed in CON vs. RNT rooms.

Likewise, pig mortality of 1.5% vs. 1.2% was not substantially different in CON and RNT rooms, respectively.

All four research stations recorded a consistent reduction in the use of heating fuel and electricity in RNT rooms vs. CON rooms. On average, RNT heating fuel use decreased by 29% and electrical use by 19%. Energy savings were valued at $1.71 (propane cost at $1.60/gal.) and $0.02 (electricity cost at $0.10/kwh) per pig leaving the nursery.

The research was supported by funds provided by the Minnesota Pork Board and the Pork Checkoff.

Researchers: Lee Johnston, West Central Research and Outreach Center, University of Minnesota, Morris; Mike Brumm, Brumm Swine Consultancy, North Mankato, MN; Steve Moeller, Ohio State University; Stephen Pohl and Robert Thaler, South Dakota State University; and Marcia Shannon, University of Missouri. For more information, contact Johnston by phone (320) 589-1711, fax (320) 589-4870 or e-mail johnstlj@morris.umn.edu.

Pigs Prefer Drinkers Opposite the Feeder

When given a choice, pigs prefer water bowl-type drinkers located opposite the feeder, according to research at Iowa State University.

The objectives of this study were to estimate aggressive interactions around the water bowl drinkers and to determine preference for a water bowl location when pigs were offered either one, two or three bowl drinkers per pen.

Nine pens of 25 gilts were used in three treatments. Treatment #1 had one water bowl drinker per pen, positioned on the same side as the feeder and close to the back wall (F). Treatment #2 was defined as two water bowl drinkers per pen, one positioned on the same side as the feeder and close to the back wall (F) and another positioned across from the feeder along the back wall (O). Treatment #3 had three water bowl drinkers per pen, two located as F and O and the third bowl positioned across from the feeder next to the alleyway (A). This option provided one water bowl drinker per eight gilts per pen (Figure 1).

Results indicated that total number and length of time engaged in aggressive actions around the water bowl drinker were not different between treatment groups.

Nursery-aged pigs preferred the water bowl drinker positioned across from the feeder along the back wall (O), followed by a preference for the drinker located on the same side as the feeder and close to the back wall (F), with the alley location (A) being the least favored location (Figure 2).

“Additional information on placement of key resources within a pen to enhance the drinking behavior for the pig is a useful tool for the swine industry and stakeholders when designing water delivery systems to enhance pig well-being and overall profitability,” says lead researcher Anna Johnson.

Researchers: Anna Johnson, Kenneth Stalder, DVM and Locke Karriker, DVM, Iowa State University; Roy Edler and J. Tyler Holck, DVM, Boehringer Ingelheim Vetmedica, Inc.; and Paul DuBois, Cargill Pork. For more information, contact Johnson by phone (515) 294-2098, fax (515) 294-9143 or e-mail: johnsona@iastate.edu.

Heat Exchanger, Heat Pump Reduce Energy Consumption

To evaluate their performance against a conventional forced-air convection heater, scientists at the Prairie Swine Centre in Saskatoon, Saskatchewan, Canada fitted grow-finish rooms with a heat exchanger and ground-source heat pump.

Data from one heating season showed that the use of the heat exchanger and heat pump produced a 52% and 39% reduction in energy consumption for heating and ventilation, respectively, compared to the conventional heater.

The goal of this project was to compare the performance of alternate heat sources and conventional heating systems in grow-finish rooms in terms of energy consumption, in-barn environment and animal productivity.

In the study, a heat exchanger combined with a forced-convection heater, a ground source heat pump, and a stand-alone, forced-convection heater were installed in 120-head, grow-finish rooms. Rooms were of similar design, pen configuration and pig capacity. For each grow-finish cycle, 360 pigs were distributed equally into the three rooms. Metering equipment measured electric consumption of the heat pump, heaters, lights, ventilation and recirculation fans, and the natural gas consumption of the forced-convection heaters in the heat exchanger and control rooms.

The heat exchanger installed (pictured) was a 1,500-cfm, aluminum-core heater ventilator, which recovers the heat energy from exhausted air by heat transfer to the incoming air.

The ground source heating system, also known as a geothermal heat pump, was composed of a heat pump and 1,800 ft. of ¾-in. diameter polyethylene pipes buried in 8.5- to 10-ft-deep trenches in the ground beside the finishing barn The buried pipes contained 20% methanol and 80% water solution to absorb heat from the ground for heating and for using the ground as heat sink when cooling is needed.

Data was collected from two grow-finish production cycles for October-December 2010 and January-March 2011 (Table 1). The mild weather during the first cycle didn’t require heating.

For the second cycle, energy consumption for heating and ventilating each of the three grow-finish rooms is presented in Figure 1. The energy consumption for heating included both the electrical and heating fuel consumption for both heat pump and heaters, while electricity for ventilation and recirculation fans comprised ventilation energy use. The energy consumption data were all converted to gigajoules (GJ) to provide a better comparison of the systems.

Average temperature and gas (ammonia and carbon dioxide) observed in all three rooms were
similar.

Of the three heating systems tested, the heat exchanger required the least energy for heating but had the highest consumption for ventilation. The heating requirement was reduced as the heat exchanger pre-heated the incoming cold air with heat from the warm exhaust air, reducing total energy use by 52% compared to the conventional room with the forced-convection heater.

The heat pump required less energy to extract heat from the ground and heat the room air compared to the conventional heater. The heat pump reduced total energy needs for heating and ventilation by 39% compared to the control room.

Pig daily gain compared favorably in all three rooms, while feed intake tended to be lower in the rooms with the heat pump and heat exchanger, compared to the conventional room.

Researchers: L. Dominguez, B. Predicala and A. Alvarado, Prairie Swine Centre. For more information, contact Bernardo Predicala by phone (306) 667-7444, fax (306) 955-2510 or e-mail: bernardo.predicala@usask.ca.