Mixed parity sows (n=3,451; PIC, Hendersonville, TN) and their litters were used to evaluate the effects of essential fatty acid (EFA) intake on sow reproductive performance, piglet growth and survivability, and colostrum and milk composition. At approximately d 112 of gestation, sows were randomly assigned to 1 of 4 corn-soybean meal-wheat-based lactation diets with 0.5 (Control) or 3% choice white grease (CWG), 3% soybean oil (SO), or a combination of 3% soybean oil and 2% choice white grease (Combination). Thus, sows were provided diets with low EFA (linoleic acid [LA] and α-linolenic acid [ALA]) in diets with CWG or high EFA in diets with SO. Lactation ADFI increased (P< 0.05) for sows fed the Combination and CWG diets compared to sows fed the Control or SO diet. Daily LA and ALA intake of sows fed the Combination and SO diets were greater (P< 0.05) than sows fed 0.5 or 3% CWG. Overall, sows consuming high EFA from the Combination or SO diets produced litters with heavier (P< 0.05) piglet weaning weights and greater (P< 0.05) litter ADG when compared to litters from sows fed diets with low EFA provided through CWG. There was no effect of sow EFA intake on piglet survivability (P>0.10). Lactation diet EFA concentration did not influence colostrum or milk dry matter, crude protein, or crude fat content (P>0.10). However, LA and ALA content in colostrum and milk at weaning increased (P< 0.05) in response to elevated dietary EFA from SO. There was no evidence for differences (P>0.10) in subsequent sow reproductive or litter performance due to previous lactation EFA intake.
In conclusion, increased LA and ALA intake provided by SO during lactation increased overall litter growth and pig weaning weights but did not affect piglet survivability or subsequent performance.