Unless you provide adequate nutrition, improvements in reproductive efficiency through selection will not be seen. Feed management is often a major limitation to reproduction in gilts and sows. Feeding the gilt is important not only for her first litter, but for her entire life. A good feeding program for sows will reduce the number culled for breeding, health, or soundness problems. Good nutrition management includes a program for gilts from selection to breeding and for sows and gilts during gestation, farrowing, and lactation.
Sows and gilts | |||
Nutrient |
Gestation |
Lactation (1) |
Boars |
| Metabolizable energy, kcal | 1,400 |
1,400 |
1,400 |
| Protein, % | 13 |
14 |
14 |
| Lysine, % | 0.50 |
0.60 |
0.60 |
| Methionine + cystine, % | 0.32 |
0.36 |
0.36 |
| Trypotophan, % | 0.09 |
0.12 |
0.12 |
| Threonine, % | 0.35 |
0.44 |
0.44 |
| Calcium, % | 0.90 |
0.75 |
0.90 |
| Phosphorus, % | 0.75 |
0.60 |
0.75 |
| Salt, % | 0.40 |
0.50 |
0.35 |
| Iron, mg | 36 |
36 |
36 |
| Copper, mg | 2.7 |
2.7 |
2.7 |
| Manganese, mg | 14 |
14 |
14 |
| Zinc, mg | 30 |
30 |
30 |
| Iodine, mg | 0.1 |
0.1 |
0.1 |
| Selenium, mg | 0.14 |
0.14 |
0.136 |
| Vitamin A, IU | 3,000 |
3,000 |
3,000 |
| Vitamin D, IU | 300 |
300 |
300 |
| Vitamin E, IU | 12.5 |
12.5 |
12.5 |
| Vitamin K, mg | 1 |
1 |
1 |
| Riboflavin, mg | 2 |
2 |
2 |
| Niacin, mg | 12 |
12 |
12 |
| Pantothenic acid, mg | 10 |
10 |
10 |
| Choline, mg | 400 |
400 |
400 |
| Vitamin B12, mcg | 10 |
10 |
10 |
| Biotin, mg | 0.06 |
0.06 |
0.06 |
| Folic acid, mg | 0.45 |
0.45 |
0.45 |
| Feed required, lb | 4 |
12 |
5 |
(1) The nutrient requirement of lactating sows increases as feed intake decreases. The nutrient content should be increased 8.3 percent for each pound below 12. (If sows will only consume 10 pounds per day, the levels of required nutrients should be increased 16.6 percent.)
A sound nutrition program begins at the time of selection (200 to 220 pounds). Keeping gilts on full feed until breeding can result in over-finishing. On the other hand, extreme reductions in feed intake will not allow for adequate growth or structural development.
Producing over-finished and exceptionally lean gilts can lead to reproductive problems. Feeding gilts 5 to 6 pounds of a good gestation diet per day (see table) will provide adequate nutrition for normal growth but will limit excessive fat deposition. Gilts from extremely lean lines may require full feeding to maintain acceptable body condition.
A typical grower diet (16 percent protein, 0.80 percent lysine) will come closer to meeting the amino acid needs of the developing gilt. However, it will not supply the gilt with adequate calcium and phosphorus. During the developmental stages, replacement gilts should be fed diets containing higher calcium and phosphorus levels than those for fed market hogs. This practice provides stores of these minerals in the bones that may be used later in life.
The ideal diet for a developing gilt contains 16 percent protein, 0.80 percent lysine, 0.90 percent calcium, 0.75 percent phosphorus, and the vitamin and trace mineral fortification of a gestation diet.
Proper feeding before and after breeding is important for maximum litter size and conception rate. Before a sow or gilt can farrow a large litter, she must produce enough eggs (ovulation rate). Supplying extra feed (2 pounds per day) 1 week before breeding (flushing) can increase the ovulation rate. This increase means more eggs for fertilization, and, with normal embryo survival, increases the number of pigs born. Immediately after breeding, feed intake should be reduced to 4 or 5 pounds per day. Over-feeding after breeding decreases embryonic survival, decreasing litter size.
During the first 80 to 90 days of gestation, the amount of feed fed depends on age, condition, and feed management. On average, sows should receive 4 to 5 pounds of a good gestation diet each day. Gilts and sows in poor condition at weaning need an extra 1 to 2 pounds a day. Sows and gilts in individual stalls require less feed energy than those in open pens.
The best way to decide how much to feed is observing body condition. Gilts and thin sows (less than 0.60 inches of backfat) need more feed (1 to 2 pounds per day), while fat sows and gilts (over 0.75 inches of backfat) need less. It is best to feed gilts and sows individually during gestation. If individual feeding is not possible, group sows and gilts by body condition into groups of no more than eight and feed accordingly.
From 20 to 35 days before farrowing, sows and gilts may benefit from extra energy intake. If pig survival during the first week of lactation is a problem, increase intake by 1 to 2 pounds or add 5 to 10 percent fat. This provides extra nutrients during maximum fetal growth, which can increase birth weights and pig survivability. This level of intake should be maintained until farrowing.
Once the sow has farrowed, she needs proper nutrition to provide milk for the survival and growth of her litter. Sows need more feed as their pigs grow. The day after farrowing, feed 5 to 6 pounds of a farrowing-lactation diet containing a laxative to prevent constipation. Gradually increase the feed so that a sow with eight or more pigs is on full feed when her pigs are 10 days old.
Sows need to eat 12 pounds of feed or more per day at this time. Many cannot or will not consume enough feed. Inadequate nutrient intake will have dramatic effects on reproductive efficiency. Low intake results in excessive weight loss, which leads to delayed cycling, no heat cycle, or poor conception.
Nutrient intake must be maintained by increasing the nutrient level of the lactation diet or stimulating appetite. Increase the level of all nutrients in the lactation diet 8.3 percent per pound of intake below 12 pounds. Start multiple feedings to increase intake. Feed 4 to 5 pounds three times a day rather than 12 to 15 pounds once a day. Also, place feed in trough or bowl-type feeders to increase intake.
For more information on feeding the sow an gilt, see "Swine
Diet Recommendations For Alabama," Extension Circular ANR-639.