Sow farm managers do not have to accept 45% or higher replacement rates. They need to improve their sow feeding, and therefore, longevity of the sow herd, says University of Minnesota swine nutritionist Sam Baidoo.

“Recognize the animals as individuals, look at each one and feed her as an individual,” he says. “Feeding has to be tailored to condition.”

Baidoo sets two goals for sow units — drop the replacement rate to 20 to 25% and raise the average parity to 4 or 5. The PigCHAMP breeding herd summary for 2000 shows the average replacement rate is 65.4%. The top 25% and 10% of PigCHAMP users have replacement rates of 42.9% and 32.1%, respectively.

Average parity is 2.5 among all PigCHAMP users, 3.0 for the top 25% and 3.5 for the top 10% of producers on the recordkeeping program.

Use Phases in Gestation

As the basis of an individualized feeding program, Baidoo suggests phase feeding in gestation. Divide the period into four phases and increase feed levels based on 3.4 lb. of feed for maintenance. The phases are as follows:

0-30 days — 1.1 × 3.4 lb.;
30-60 days — 1.3 × 3.4 lb.;
60-90 days — 1.5 × 3.4 lb., and
90 days to farrowing — 1.7 × 3.4 lb.

For example, a sow would require 3.7, 4.4, 5.1 and 5.8 lb. of feed for the four periods, respectively.

The goal is to take the sow with 0.48 to 0.56 in. of backfat at breeding to 0.72 to 0.76 in. of backfat at farrowing. Keep in mind there are genetic and environmental differences in each sow herd.

Baidoo suggests the diet should be 13 or 14% protein and 1.45 Mcal ME/lb. of diet (ME=Metabolizable Energy).

Gestation Feeding

Frank Aherne, swine nutritionist at the University of Alberta, sets his gestation feeding goal at attaining 0.72 to 0.80 in. (P2 backfat, at the last rib and 2.5 in. off the midline) by farrowing.

“Measure backfat at the time of breeding and make a guesstimate of sow weight,” he says. Based on that information, feed according to Table 1.

Aherne notes that the feed intakes are based on mid-gestation weights, and therefore, do not need to be adjusted throughout gestation.

Lactation Feeding

Aherne balances his lactation feeding strategy between NRC (National Research Council) requirements and age-old advice.

“On our farms, we try to maximize feed intake, but avoid dips in feed intake in mid-lactation,” he says. “We do this by adopting a feeding strategy based on sow size and litter size.”

Here's the basics of Aherne's system for feeding lactating sows:

  • Feed 1% of the sow's weight in kilograms (2.2 lb.) for maintenance; or

  • If you don't know the sow's weight, feed 3.3 lb. for the sow plus 1.1 lb. for every pig in the litter.



He also suggests this practical feeding system:

  • Day of farrowing (Day 0): feed 3.3 to 4.4. lb.

  • Days 1-2: feed 5.5 lb./day.

  • Days 3-7: increase feed intake gradually to reach a maximum feed intake by Day 8 of lactation. The maximum feeding level for sows based on the above is 3.3 lb. for the sow and 1.1 lb. for each pig in the litter.

  • Days 8-12: Maintain sow at target maximum allowance if she has reached it. This will help to avoid any dips in feed intake, he says.

  • Day 12 to weaning: If possible, gradually increase the feed allowance above the targeted maximum allowance. Aherne suggests feeding three times a day or using a wet feeding system for first and second litter sows and sows with large litters.



Table 1: Feed Requirements for Gestating Sows (Day 0 to Day 100)

Backfat (P2*) at Breeding, in.
Weight at Breeding, lb. 0.40 0.44-0.48 0.52-0.56 0.60-0.64 0.68-0.72
Light 253-330 5.28 5.06 4.84 4.62 4.18
Medium 330-385 5.50 5.28 5.06 4.84 4.62
Heavy 385-440 5.94 5.72 5.50 5.28 5.06
Very Heavy 440-495 6.38 6.16 5.94 5.72 5.28
Diet contains 13.5% protein, 0.55% lysine and 1.36 Mcal ME/lb.
*P2 backfat as measured at the last rib and 2.5 in. off the midline.