Highly prolific sows were those that gave birth to 12 pigs/litter total, 11 pigs live, and weaned 10. DanBred sows may farrow 13 to 14 live pigs and wean 12 to 13. To raise 12 or 13 pigs, sows must be fed to support milk production without compromising body condition and subsequent reproductive performance. A 400 lb sow needs 6.3 Mcal/d ME for maintenance and 3.15 Mcal ME/lb litter weight gain. If pigs gain 10 lb from birth to weaning, a sow weaning 12 to 13 pigs needs 26 to 28 Mcal/d ME to support milk production as well as maintain body tissue reserves. To meet caloric needs, sows must consume 17 to 18.5 lb/d of a lactation diet that contains 1.5 Mcal/lb ME. The lactation feed should also provide at least 80 g/d of lysine to support this level of milk production.
In the US, sows in highly productive farms producing in excess of 28 P/S/Y are averaging 13 to 14 lb/day or more of lactation feed intake. However, since sows really need to be eating in excess of 17 lb/d, there is a gap between nutrient requirements and intake that may compromise milk production and cause sows to break down body tissue reserves. The challenge for producers is to minimize sow tissue losses during lactation to promote successful breed back within 4 to 7 days postweaning. There are several strategies producers can use to meet this challenge.
Feeder Technology: Ad libitum feeder technologies such as tube feeders, wheel feeders, and ball valve feeders are being used successfully to increase feed intake by sows in lactation. In general, ad libitum feeders will increase lactation intake by 1 to 2 lb/sow/d vs. hand feeding, and potentially more depending on how hand feeding was previously managed.
Diet Formulation: Lactation diet formulation needs to strike a balance between nutrient needs, palatability, feed intake and cost. Nutritionists may be tempted to formulate lactation diets with high levels (>4%) of added fat to help sows achieve targets for energy intake. However, reducing added fat to 2-3% of the diet may result in an increase in daily feed and energy intake if fat quality is suspect. Formulating to high levels of lysine (1.10 to 1.30%), with special attention paid to start up or young herds, is very important and will help support milk production. However, keep in mind that increasing sow feed intake 1 to 2 lb/day can result in more total nutrient intake by sows than increasing formulated nutrient levels.
Mycotoxins: Producers are rightly concerned about mycotoxin levels in corn and corn by-products such as distiller’s dried grains with solubles (DDGS). In certain parts of the US, the 2009 corn crop was heavily contaminated with vomitoxin (DON) and in some cases, zearalenone (ZON). In sows offered feed ad libitum, 1 to 2 ppm DON will result in reduced intake, and at 5 ppm or more, DON will result in outright feed refusal. ZON does not affect feed intake
but mimics the effect of estrogen, and so can have a negative impact on reproductive performance. It is critical that quality controls are put into place at feed mills to monitor DON and ZON levels in incoming ingredients so that sows can receive high quality, palatable feed. Producers also need to ensure that regular cleanouts of feed bins occur on farm so that mold and mycotoxins do not build up in bins and feed systems. Lactation feeders should also be kept clear of moldy, spoiled feed.
Water: Sows must have ready access to good flows of palatable water. If flow rates are low (< 2 cups/min), sows drink less water which results in lower feed intake. If flow rates are too high (>4 cups/min with strong pressure out of the nipple waterer), young sows especially may back away from the nipple waterer, reducing water and feed intake. Low water and feed intake start the downward spiral in body condition, as sows use body reserves to support the demands of milk production.
Environment and Health: Providing sows with a comfortable environment promotes feed intake. Sows maintained in too warm an environment (>72? F) with high levels of humidity (>70%) and gases such as ammonia will eat less feed in lactation. Sick sows with fevers will also have reduced feed intake, so it is important to diagnose and treat sick sows as quickly as possible.
Body Condition: Sows must enter the farrowing house with adequate body reserves to support milk production but should not be over-conditioned or feed intake will suffer. In general, this means 10th rib backfat at farrowing should be between 16 and 19 mm. Most farms accomplish this by feeding to condition up to day 90 of gestation, and then bumping feeding rate 1 to 3 lb/sow/day to day 113 of gestation to accommodate
By Betsy Newton
Danbredna