How to Get More Small Pigs to Market

Young Animal : Management

Dan McManus, DVM

Young Animal Swine, Technical Sales Specialist

A real dilemma in today’s production world is that 5-10 percent of pigs delivered to a finisher never make it to an acceptable market weight and are sold discounted, off the market.
To help light-born and light-weaned pigs excel to market weight, we first must understand the reason we may have small pigs and then outline an action strategy.

Understanding the cause

Small birthweights: Many of the lightweight pigs delivered to finishing systems are small at birth. 

Pigs may be born small due to: 
  1. Large litter sizes: Sows that have large litters (>15 pigs) tend to have small birthweight pigs. The uterus does not have space and the ability to supply enough nutrients to every pig in a large litter.
  2. Older parity sows: As sows age and go through the farrowing process, their uterus becomes damaged and they lose the ability to maintain an even litter size. Older sows have more variation in their litter birthweight and therefore, more small pigs.
  3. Thin sows: Under-conditioned sows are more likely to have small birthweight pigs. Feed sows to ensure a body condition score of 3 on a 5-point scale to promote performance.
  4. Early farrowing sows: Sows farrowing less than 114 days of gestation will have greater potential for reduced birthweight litters. Be especially careful not to induce farrowing prior to day 115 of gestation. 

Farrowing house management
A variety of problems can occur in farrowing rooms that result in small, lightweight pigs at weaning. 

Pigs may have lower weaning weights due to:
  1. Poor cross-fostering: All pigs need a good supply of milk. Pigs falling out should be moved to nurse sows to ensure good intake of milk.
  2. Health problems: Diarrhea or any other health problem can reduce weaning weights and increase variation among litters.
  3. Decrease in sow lactation intake: Summer heat can cause sows to consume less feed. Off-feed sows can be less able to provide for pigs resulting in more small pigs at weaning.
  4. Decrease in weaning age: Weaning pigs early can result in lighter pigs at weaning. 
To prevent small birthweights or end of nursery weights, work with the sow facility manager and employees to prevent as many of these problems at the sow farm before the pigs enter nurseries and wean-to-finish barns. 

Creating an action plan
Regardless of management strategies, fallout or lightweight pigs are to be expected. 

When pigs enter today’s nursery facilities, most small pigs are fed a standard feed budget on the average weight of the pigs placed in a barn, as shown in this table.

Table 1. Standard budget for 12-pound weaned pig delivered from a sow farm
A table with 5 columns with one product per column showing number of pounds for 12 pound weaned pigs delivered from a sow farm. UltraCare 100=0, UltraCare 200=4, UltraCare 300=7, UltraCare 400=14, UltraCare 500=Balance
However, when pigs are fed to an average, the lighter pigs most often do not receive the nutrients they require to catch up to their counterparts. This is shown in the following table, which outlines a difference in consumption versus feeding to an average

Table 2. Actual and needed feed consumed by small, lightweight pigs
A table with 5 columns with one product per column showing number of pounds by actual and needed feed consumed by small, lightweight pigs. UltraCare 100 Actual=0 Needed=3, UltraCare 200 Actual=3 Needed=5, UltraCare 300 Actual=5.7 Needed=7, UltraCare 400 Actual=11 Needed=14, UltraCare 500 Actual=Balance Needed=Balance
In this example, the small pigs needed 8 pounds of the first 2 diets to meet their biological needs. However, since the farm only uses a single feed budget, these smaller, light weight pigs only received 3 pounds of UltraCare® 200 starter feed because of their small size and lower intake.
To solve this problem, implement a small, lightweight pig budget as follows:
  1. Sort the smallest 10-20% of the pigs into designated small pens.
  2. Place a feed card on their feeder with the desired amount of feed per diet to be fed.
  3. Use bags or a separate bin to feed the small pigs. 
NOTE: Small pigs will lag about 1 week behind the rest of the group in diet changes. 

Monitoring the results
Research trials show that feeding the small pigs differently can result in a 4-5 pound heavier pigs as they exit the nursery phase. In farm trials, the smallest pigs in an average group of 50 pound pigs weighed 40 pounds rather than 35 pounds.

The results also translated into the finishing barn. Let’s look at what happens 125 days later to pigs in the finishing barn, as shown below.

Table 3. Initial and market weights of average and small pigs fed the standard budget or feeding the small pigs a separate feed budget. 
A table with three columns showing the initial and market weights of average and small pigs fed the standard budget or feeding the small pigs a separate feed budget. Average pigs Initial Weight to Finisher=50 pounds and Market Weight=265 pounds, Small pigs Initial Weight to Finisher=35 pounds and Market Weight=195 pounds, Small Pigs Fed Right initial weight to finisher=40 pounds and Market Weight=230 pounds

An area to highlight is: the 5-pound spread at end of nursery translated into a 35-pound difference at finishing.
This added market weight resulted in financial returns for the producer, as shown here.

Table 4. Value per head of feeding small pigs the standard budget or on a separate feed budget. 
A four column table showing value per head of feeding small pigs the standard budget or on a separate feed budget in pounds. Small pigs Market Weight=195, Market $/cwt=$32 Value/head=$62.40. Small Fed Right Market Weight=230, Market $/cwt $44, Value/head=$101.20
In this case, for every pig pushed into a desirable weight category, producers gained $38.80 per head.

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