Lower nursery temp at night cuts fuel use

Lower nursery temp at night cuts fuel use

*John H. Goihl is president of Agri-Nutrition Services Inc., Shakopee, Minn. To expedite answers to questions concerning this article, please direct inquiries to Feedstuffs, Bottom Line of Nutrition, 5810 W. 78th St., Suite 200, Bloomington, Minn. 55439, or email [email protected]

THE swine industry continues to evaluate the production of greenhouse gases (GHGs) from today's production systems.

One approach to reduce GHGs is to reduce the consumption of fossil fuels used in pork production systems. One way to reduce the amount of fossil fuels used is to reduce the ambient temperature within the buildings that require supplemental heat. This approach may not be dramatic, but it will contribute to incremental improvements in reducing GHGs.

Previous research conducted 20 years ago demonstrated that reducing room temperature during nighttime hours — reduced nocturnal temperature (RNT) — significantly reduced consumption of heating oil but had variable effects on nursery pig performance.

The RNT concept hasn't been adopted in the swine industry because of changes in production facilities, equipment and the genetic potential of pigs since this original research was done.

With an increased focus on the environmental sensitivity of pork production facilities and reducing production costs, however, a re-evaluation of the RNT regimen in modern facilities and genetics needed to be done.

Swine researchers L.J. Johnston of the University of Minnesota, M.C. Brumm of the University of Nebraska, S.J. Moeller of The Ohio State University, S. Pohl and R.C. Thaler of South Dakota State University and M.C. Shannon of the University of Missouri conducted two studies to determine the effects of an RNT regimen on consumption of fossil fuels and pig performance using current genetic lines of pigs in today's modern swine production facilities.

 

Experiment 1

The first experiment was a collaborative effort among three of the participating universities.

At each station, two nursery rooms in the same building were used simultaneously for each replicate of the experiment. Pigs were weaned at 16-22 days of age and assigned randomly to the rooms. Each room was assigned one of two temperatures.

A total of 820 pigs were on treatment 1, and 818 pigs were on treatment 2.

In treatment/room 1 (control), the temperature was set at 30 degrees C for the first seven days and then was reduced 2 degrees C per week through the remainder of the experiment.

In treatment/room 2, the temperature initially was set at 30 degrees C for the first seven days. Beginning on the night of day 7, the room temperature setting was reduced 6 degrees C from the daytime temperature between 7 p.m. and 7 a.m., when the room temperature setting was returned to the same as room 1.

Each station conducted two replicate trials, with room temperatures switched between rooms for the second trial. All pigs were provided ad libitum access to feed and water throughout the experiment, which lasted for 35 days in Nebraska and 42 days in Missouri and Minnesota.

Total weight and number of pigs at the beginning and end of the experiment were recorded, along with feed consumed.

Heating fuel consumption was measured directly with independent gas meters for each room or calculated from the recorded operation time for each furnace. The electricity used was recorded for each room.

The experiment was conducted twice at three locations. Nebraska did the experiment from December 2004 to January 2005 with 118 head and again from November 2005 to January 2006 with 120 total head. Missouri did its trials from February 2006 to March 2006 with 240 head and from March 2006 to April 2006 with 240 head. Minnesota trials ran from June 2007 to July 2007 with 415 head and from February 2008 to March 2008 with 505 head.

Table 1 summarizes the performance of pigs and energy used.

The researchers provided the following interpretations of these results from experiment 1:

* No significant station-by-treatment interactions were observed for any of the response criteria.

* The room temperature treatments had no influence on the various performance criteria measured.

* The RNT room reduced consumption of heating fuel by 18% and electricity by 9%. These differences were not statistically different.

 

Experiment 2

Experiment 2 was a collaborative effort among researchers at the University of Minnesota, University of Missouri, Ohio State University and South Dakota State University. Each station completed two replicate trials similar to experiment 1. The pigs were weaned between 16 and 22 days of age and were on trial for 28-42 days.

The two room temperature treatments were as follows:

* Room/treatment 1 (control) was the same as for experiment 1.

* Room 2 (RNT) had the temperature set at 30 degrees C for the first four days. Beginning on day 5, daytime temperatures were set to equal room 1, but temperature controllers were set to reduce the nighttime temperature by 8.3 degrees C from the daytime temperatures between 7 p.m. and 7 a.m. Daytime temperatures were reduced 2 degrees C per week — the same as room 1 for the remainder of the experiment.

The heating fuel and electricity used were recorded in the same way as experiment 1. Room temperature treatments were switched between rooms for the second replication. The same performance data were collected as for experiment 1.

The time periods of experiment 2 were: in Ohio from January to February 2010 with 700 pigs and from March to May 2010 with 720 pigs; in South Dakota from January to February 2010 with 50 pigs and from February to March 2011 with 100 pigs; in Missouri from March to April 2010 with 180 pigs and from December 2010 to January 2011 with 180 pigs, and in Minnesota from December 2009 to January 2010 with 536 head, February to March 2010 with 595 pigs, November to December 2010 with 607 pigs and January to February 2011 with 630 head.

Table 2 summarizes the pig performance and energy used.

The researchers provided the following interpretations of the results from experiment 2:

* No significant treatment-by-station interactions existed.

* Pig performance over the entire experimental period was nearly identical between rooms.

* The heating fuel and electricity used in the RNT room were decreased 30% and 20%, respectively.

In both studies and at every station, pig performance and overall health status were unaffected by the RNT regimen used. Previous research has imposed 6-10 degrees C reductions in nighttime temperature and reported no differences in pig performance or health.

In previous studies where nighttime temperature was decreased immediately upon pigs' entry into the nursery, feed intake increased, but so did the occurrence of pig removals due to death and unthriftiness.

This observation, along with the results of this study, suggest that newly weaned pigs may benefit from a brief acclimation period of four to seven days in the nursery to recover from weaning and transportation stress and to establish consistent feed intake before an RNT regimen can be imposed successfully.

Other researchers have also reported that nursery pigs prefer cooler room temperatures at night compared to daytime temperatures.

In these two studies, the magnitude of difference in room temperatures between rooms was difficult to maintain after the first 10 days. This decreased differential is the result of the increasing bodyweight of the pigs.

Researchers have reported that sensible heat production increases from about 65 Btu per hour when pigs weigh 7 kg to 240 Btu per hour when pigs weigh 22 kg. This four-fold increase in heat production as pigs grew contributed to the heat supply in the room and explains the difficulty of maintaining the temperature differential between the two rooms at night.

The reduction in energy consumption not only reduces production costs but also results in environmental benefits of reduced emissions of GHGs and carbon dioxide.

 

The Bottom Line

This study demonstrated that imposing an RNT regimen from 7 p.m. to 7 a.m. does not have any detrimental effects on pig performance and health, provided that pigs are allowed a brief acclimation period to establish a normal feed intake pattern and consumption. The reduction in fossil fuel consumption reduces production costs.

 

Reference

J. Anim. Sci. Vol. 91. No. 7.

 

1. Performance of pigs and energy used

Criteria

-Room-

 

1

2

Number of rooms

6

6

Initial pig weight, kg

6.2

6.2

Final pig weight, kg

23.7

23.7

Avg. daily gain, kg

0.43

0.43

Avg. daily feed intake, kg

0.62

0.62

Gain:feed

0.69

0.69

Heating fuel used, Btu/pig/day

9,658

7,958

Electricity used, kWh/pig/day

0.138

0.125

Mortality, %

1.1

1.0

 

2. Pig performance and energy used

Criteria

-Room-

 

1

2

Number of rooms

9

10

Initial pig weight, kg

6.2

6.2

Final pig weight, kg

21.8

21.5

Avg. daily gain, kg

0.45

0.44

Avg. daily feed intake, kg

0.61

0.60

Gain:feed

0.75

0.75

Heating fuel used, Btu/pig/day

10,019

7,061

Electricity used, kWh/pig/day

0.026

0.021

Mortality, %

1.5

1.2

 

 

Volume:85 Issue:44

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