Pulling the Lever: Should You Slow Down Pig Growth?

02:05PM Apr 07, 2020
Finishing hogs
( National Pork Board and the Pork Checkoff )

By Omarh Mendoza and Caleb Shull, The Maschhoffs

With the recent market dynamics, it has become evident that having the ability to slow down pig growth would be beneficial. While we are typically striving to increase pig growth rates, certain conditions do exist where it would pay dividends to restrict pig growth rates. Such conditions include extreme situations like restricted harvest capacity. However, other situations do exist where it may be beneficial to control or reduce the rate of pig gain. Below are some options for slowing down pig growth worth considering. When considering these options, animal care standards must be a priority and not compromised. 

1.    Reduce feed intake through increased dietary bulk density.
Use of high levels of dietary fiber (using corn coproducts such as DDGS or corn germ meal) will reduce average daily gain (ADG) ranging from 4% to 8%. Research has shown that you have to push neutral detergent fiber (NDF) levels to at least 18% to 20% to achieve sustained reductions in ADG as pigs will adjust intake with only moderate levels of dietary fiber. Cost and availability of high fiber corn coproducts does vary and may affect the feasibility of this option.

2.    Remove all growth-promoting technologies from diets.
This is easy to implement, but the negative consequences of losing the other benefits (e.g., feed conversion, carcass yield, etc.) these products offer must be considered.

3.    Reduce amino acid levels in diets.
Lowering the lysine-to-calorie ratio will effectively reduce ADG by 10% or more, depending on the level and timing. However, this will also make your pigs less efficient and could increase carcass backfat if done in late finishing. A qualified nutritionist may also be able to adjust amino acid ratios slightly to further reduce ADG.

4.    Tighten feeder adjustments.
Reducing feeder adjustment can reduce ADG by up to 8%. This should done with oversight to avoid plugging feeders and may require switching to meal feed.

5.    Use other feed additives.
Feed additives such as calcium chloride (CaCl) or intake-suppressing flavors do offer some potential for reducing intake and ADG and warrant further investigation.

6.    Restrict floor space.
Tightening up pigs during the grow-finish period has shown to reduce ADG by 10% or more.  

7.    Restrict feed access.
Reducing ADG through physical feed restriction is certainly effective but can be difficult to manage. Severe restrictions will negatively affect feed conversion and increase weight variation and may reduce the number of pigs reaching full market value.

8.    Increase barn temperature.
Reducing the ventilation rate will increase the temperature and humidity in the barn, which can reduce ADG by 10% or more in late finishing pigs, depending on the level of temperature and humidity increase. Any changes to ventilation rates obviously requires close oversight by trained personnel.

Again, animal welfare should always be a priority when making management decisions and consult with a qualified nutritionist. Multiple “levers” exist to decrease pig growth to varying degrees. Regardless of the lever, there most always will be a cost to incur, whether that be product cost, poorer feed conversion or increased yardage cost. The key is to know when to pull which lever to ensure the revenue opportunity justifies the added cost.

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