Sow and piglet eating patterns could have an impact on their performance in later parities and in finishing, respectively.

Creating more creep feed “eaters” in a litter of baby pigs may help improve postweaning performance and offer additional benefits for smaller pigs, according to a recent Kansas State University (KSU) study.

Feeding highly digestible dry feed to baby pigs while still nursing the sow has been increasing in U.S. pork production operations the past few years. KSU researchers say this increase in creep feeding may be driven by a trend toward older weaning ages. However, evidence that creep feeding is beneficial is somewhat limited, especially when pigs are weaned at less than four weeks of age.

A number of studies have shown a positive relationship between preweaning growth and postweaning performance. Increasing nutrient availability for suckling piglets is considered a major contributor to improving birth-to-weaning growth rate.

Producers can make sure the baby pigs get the necessary nutrients in two ways — by feeding high, nutrient-dense lactation diets to improve sow milk output, or by providing highly digestible creep feed to piglets while suckling.

Previous studies have looked at the independent effects lactation feed intake and creep feeding can have on pre- and postweaning performance. However, no single study has focused on the joint effect of these two nutritional regimens.

It has been suggested that creep feeding reduces the nutritional load on lactating sows. Creep feeding may be especially beneficial to sows with large litters by helping to reduce lactation weight loss and wean-to-estrus interval.

KSU researchers set out to evaluate the effect lactation feed intake and creep feeding might have on sow body weight loss, sow backfat thickness and wean-to-estrus intervals. They also studied how creep feeding impacted preweaning and postweaning piglet performance.

Study Parameters

Twenty-eight sows from three batches farrowed in the fall of 2006 accounted for the 84 sows blocked according to parity and date of farrowing, and allotted to four experimental treatments. Treatments included ad lib vs. restricted lactation feed intake and no creep feeding vs. creep-fed litters.

Piglets were crossfostered within each block to standardize litter weights and litter size to more than 11 pigs. The creep-fed experiments offered pellets using a rotary creep feeder with a hopper. Pigs were weaned at 21 days of age.

Ad lib sows were allowed free access to a common lactation diet from the third day of lactation. Restricted sows were fed 25% less than those fed ad lib. Weekly sow feed intake was recorded to calculate total and average daily feed intake.

Sows were weighed and P2 backfat thickness (2.5 in. off midline at 10th rib) was measured postfarrowing and at weaning. Estrous detection, using a back pressure test, was performed twice a day from weaning until Day 13 after weaning to determine days to estrus and percentage of sows returning to estrus within 14 days.

At weaning, 624 out of 819 pigs were blocked according to initial weight and whether or not they had been creep fed. These pigs were used in three, 28-day nursery trials. Extra pigs were also housed in the nursery facility and fed a common diet. Pigs and feeders were weighed weekly until Day 28 postweaning to calculate average daily gain, average daily feed intake and feed-to-gain ratio.

Creating ‘Eaters’

A significant part of the research focused on testing the importance of creating “eaters” — the piglets within the litter that actually ate creep feed.

Chromic oxide was added to the creep feed to serve as a dye marker to indicate which pigs had eaten the feed. By taking anal swabs and analyzing fecal samples, researchers were able to determine the eaters in each litter. Non-eaters in the creep-fed litters were those pigs that never showed green-colored feces.

Pigs that were not provided with creep feed were designated as “no-creep” pigs. “The most interesting finding was that pigs that actually consumed creep feed, which were the eaters, grew faster and were heavier after weaning than pigs that had not consumed creep feed,” says Rommel Sulabo, KSU graduate student.

Creating more creep feed eaters in whole litters may be beneficial in improving postweaning performance. Therefore, Sulabo says there is a need to investigate methods by which feeding behavior can be encouraged. There is some indication that smaller pigs at birth have a higher probability of becoming creep feed eaters, while heavier pigs are more likely to become non-eaters. This suggests larger pigs have greater ability to compete for prime suckling positions on the udder, and given the choice, seemed to prefer milk over the creep feed, say the researchers. Creep feed, then, provides an alternative nutritional source for the smaller, less competitive pigs.

Lactation, Creep Feeding Interactions

The researchers also wanted to test the value of creep feeding when the nursing piglets' nutrient intake was compromised. To do this, sows fed on an ad lib basis were compared to sows fed at 75% of the level of the ad lib sows.

Although litters of restricted-fed sows had 33% greater creep feed intake than litters of ad lib fed sows from Days 3 to 7, no differences were observed in other periods (Figure 1).

Figure 2 indicates creep feed intakes greater than 0.1 lb./litter were attained from Days 13 and after.

About 59% of the creep-fed piglets were categorized as eaters, while 41% were categorized as non-eaters (Figure 3). Of pigs identified as eaters, 23%, 20% and 57% were positive for creep feed consumption on Days 7, 14 and 21, respectively (Figure 4).

Total creep feed intake did not differ between ad lib and restricted-fed sows, which suggests that a limited nutrient supply to both sows and litters did not drive piglets to consume more creep feed. About 72% and 77% of the total creep feed intake of litters of restricted and ad lib-fed sows, respectively, was consumed in the last week prior to weaning.

The researchers found there was no interaction between lactation feed intake and creep feeding. Creep feeding for 18 days did not affect sow body weight and backfat loss, but increased days to estrus. The researchers say the amount of litter creep feed intake observed in this study was too small to generate any appreciable, nutritional savings to lactating sows that would reduce using body reserves. The impact of creep feeding on reducing nutrition requirements of the sow may be greater with older weaning ages, but does not appear to be beneficial in a 21-day lactation period. The effects of lactation feeding level and creep feeding on sow performance are shown in Tables 1 and 2.

The effects of lactation feeding level and creep feeding on pig and litter performance are shown in Tables 3 and 4. Lactation feeding level had no effect on litter size at weaning and preweaning mortality rate. Ad lib sow feeding improved total and daily gains of litters and tended to increase litter weaning weights compared to limit-fed sows. Likewise, total gain, daily gain and weaning weights of individual pigs were higher with ad lib-fed sows. These results agree with other studies that demonstrate the benefits of high lactation feed intake on preweaning growth rate.

More to Come

This was the first in a series of three creep feeding experiments conducted by KSU researchers. Results of the other two experiments will be featured in an upcoming issue of National Hog Farmer.

KSU researchers involved in these projects included Rommel C. Sulabo; Mike D. Tokach; J.Y. Jacela; E.J. Wiedemann; Jim L. Nelssen; Steve S. Dritz, DVM; Joel M. DeRouchey and Robert D. Goodband. For additional information, contact Sulabo at (785)532-1270.

Table 1. Effects of Lactation Feeding Level and Creep Feeding on Sow Performance (Interactive Effects)ab
Lactation feeding level×creep feeding
Restricted Ad lib
Item No Yes No Yes
Number of sows 19 19 20 20
Lactation length, days 21.0 21.1 20.9 21.1
Average parity 1.5 1.6 1.5 1.6
Lactation feed intake, lb.
Total, Day 0 - 21 151.1 148.1 221.3 217.1
Average daily feed intake 8.0 7.9 10.9 10.6
Sow weight, lb.
Postfarrowing 475.6 487.0 463.8 478.2
Weaning 422.4 428.3 433.8 443.1
Change -53.9 -51.8 -30.8 -35.3
Backfat, in.
Postfarrowing 0.70 0.622 0.673 0.637
Weaning 0.496 0.476 0.528 0.484
Change -0.200 -0.146 -0.145 -0.153
Days to estrusg 4.7 5.7 5.1 5.2
Return to estrus, %h 73.7 68.4 90.0 90.0
aThree groups of sows (total = 78, PIC Line 1050) were blocked according to day of farrowing and parity and allotted to four treatments in a 2×2 factorial with lactation feeding level (Restricted vs. Ad lib) and creep feeding (No vs. Yes) as factors.
bThere was no significant interaction (P>0.10) between lactation feeding level and creep feeding on any parameter measured.
cSows on the restricted feeding program were fed 25% less than those fed ad lib.
dCreep feed with 1.0% chromium oxide was offered ad lib from Day 3 to weaning (21 ± 0.1 d).
e,fMeans in the same row with different superscript differ (P<0.05).
gFor sows returning to estrus within 14 days postweaning.
hPercentage of sows returning to estrus within 14 days postweaning.
Table 2. Effects of Lactation Feeding Level and Creep Feeding on Sow Performance (Main Effects)ab
Lactation feedingc Creep feedingc
Restricted Ad lib No Yes
Number of sows 38 40 39 39
Lactation length, days 21.1 21.0 21.0 21.1
Average parity 1.6 1.5 1.5 1.6
Lactation feed intake, lb.
Total, Day 0 - 21 149.6f 219.2f 185.9 182.9
Average daily feed intake 8.0f 10.8f 9.4 9.3
Sow weight, lb.
Postfarrowing 481.3 471.0 469.7 482.6
Weaning 425.4 438.5 428.1 435.7
Change -52.9e -33.0f -42.4 -43.5
Backfat, in.
Postfarrowing 0.661 0.653 0.689 0.630
Weaning 0.488 0.508 0.511 0.480
Change -0.173 -0.145 -0.178 -0.150
Days to estrusg 5.2 5.1 4.9e 5.4f
Return to estrus, %h 71.0e 90.0f 82.1 79.5
aThree groups of sows (total = 78, PIC Line 1050) were blocked according to day of farrowing and parity and allotted to four treatments in a 2×2 factorial with lactation feeding level (Restricted vs. Ad lib) and creep feeding (No vs. Yes) as factors.
bThere was no significant interaction (P>0.10) between lactation feeding level and creep feeding on any parameter measured; means of main effects are reported.
cSows on the restricted feeding program were fed 25% less than those fed ad lib.
dCreep feed with 1.0% chromium oxide was offered ad lib from Day 3 to weaning (21 ± 0.1 d).
e,fMeans in the same row with different superscript differ (P<0.05).
gFor sows returning to estrus within 14 days postweaning.
hPercentage of sows returning to estrus within 14 days postweaning.
Table 3. Effects of Lactation Feeding Level and Creep Feeding on Litter and Pig Performance (Interactive Effects)ab
Item Lactation feeding level × creep feeding
Restricted Ad lib
No Yes No Yes
No. of litters 19 19 20 20
Pigs/litter
Day 3 (start creep) 11.1 10.9 10.8 11.1
Day 21 10.3 10.5 10.1 10.7
Mortality, % 7.5 4.3 7.1 3.6
Litter weight, lb.
Day 3 (start creep) 38.2 40.3 36.5 40.2
Day 21 123.9 126.2 126.0 139.2
Litter weight gain, lb.
Total 94.6 94.8 97.6 108.2
Average daily gain 5.20 5.20 5.34 5.94
Pig weight, lb.
Day 3 (start creep) 3.8 3.8 3.7 3.8
Day 21 12.1 12.0 12.5 13.1
Pig weight gain, lb.
Total 9.2 9.0 9.6 10.2
Average daily gain 0.52 0.51 0.54 0.58
aThree groups of sows (total = 78, PIC Line 1050) were blocked according to day of farrowing and parity and allotted to four treatments in a 2 × 2 factorial with lactation feeding level (Restricted vs. Ad lib) and creep feeding (No vs. Yes) as factors.
bThere was no significant interaction (P>0.10) between lactation feeding level and creep feeding on any parameter measured.
cSows on the restricted feeding program were fed 25% less than those fed ad lib.
dCreep feed with 1.0% chromium oxide was offered ad lib from Day 3 to weaning (21 ± 0.1 d).
e,fMeans in the same row with different superscript differ (P<0.05).
Table 4. Effects of Lactation Feeding Level and Creep Feeding on Litter and Pig Performance (Main Effects)ab
Item Lactation feedingc Creep feedingd
Restricted Ad lib No Yes
No. of litters 38 40 39 39
Pigs/litter
Day 3 (start creep) 11.0 10.9 11.0 11.0
Day 21 10.4 10.4 10.2 10.6
Mortality, % 5.9 5.3 7.3e 3.9f
Litter weight, lb.
Day 3 (start creep) 39.3 38.6 37.4e 40.3f
Day 21 125.1e 132.6f 124.9e 132.7f
Litter weight gain, lb.
Total 94.7e 102.9f 96.1 101.5
Average daily gain 5.20e 5.64f 5.27 5.57
Pig weight, lb.
Day 3 (start creep) 3.8 3.8 3.7 3.8
Day 21 12.0e 12.8f 12.3 12.5
Pig weight gain, lb.
Total 9.1e 9.9f 9.4 9.6
Average daily gain 0.52e 0.56f 0.53 0.55
aThree groups of sows (total = 78, PIC Line 1050) were blocked according to day of farrowing and parity and allotted to four treatments in a 2×2 factorial with lactation feeding level (Restricted vs. Ad lib) and creep feeding (No vs. Yes) as factors.
bThere was no significant interaction (P>0.10) between lactation feeding level and creep feeding on any parameter measured; means of main effects are reported.
cSows on the restricted feeding program were fed 25% less than those fed ad lib.
dCreep feed with 1.0% chromium oxide was offered ad lib from d 3 to weaning (21 ± 0.1 d).
e,fMeans in the same row with different superscript differ (P<0.05)