High producing sows are under catabolic (resulting in tissue loss) and oxidative stress during lactation and this will impair sow reproductive performance. Moreover, reduced feed intake during high ambient temperatures aggravates these conditions. Providing proper nutrition to sows during periods of stress is extremely important in order to maintain productivity. In particular linoleic acid, which is a precursor of eicosanoids that are important in reproduction, has been shown to be required for optimal subsequent reproductive performance of sows. Linoleic acid is an unsaturated fatty acid prone to peroxidation, which may further exacerbate the oxidative stress status of high producing lactating sows. The purpose of the current study was to determine and verify the impact of linoleic acid supplementation on reproductive performance of sows under practical field conditions and evaluate the impact of commercial antioxidants on oxidative stress and sow performance. A total of 605 sows entered the farrowing room and finished lactation in groups of 22 to 24 sows per group. Sows were fed one of 4 treatments, consisting of diets with 2 levels of linoleic acid (LA; 1.4 or 3.3%) and each of these diets were either not supplemented or supplemented with a commercial antioxidant blend (0 or 0.1%). Sow body weight change and feed intake during lactation were not affected by dietary treatments. Sow body weight at the end of lactation tended (P=0.09) to be higher for mature sows consuming 1.4% LA than other treatments. Feed efficiency was improved (P=0.03) in sows consuming 1.4% versus 3.3% LA in their diets. Litter performance, number of pigs weaned and pre-weaning mortality were not affected by dietary treatment or parity group. The impact of diets on oxidative stress markers varied, were some markers (protein carbonyls, indicating protein damage) were higher and others (malondialdehyde, indicating damage to lipids) were lower in sows fed linoleic acid. Total antioxidant capacity in serum and vitamin E concentrations in serum and milk were lower (P=0.02) in sows fed linoleic acid. Antioxidant supplementation tended (P=0.07) to increase serum vitamin E by 13%. For subsequent reproductive performance, no improvements in wean-to-estrus interval, percentage of sows bred, returns, wean-to-farrow interval, farrowing rate, culling rate, or number of pigs born alive were observed. Collectively, these data indicate that supplementation of antioxidants during lactation did not improve oxidative stress status of sows, nor did it affect performance of sows and litters during lactation or subsequent reproductive performance of sows. Furthermore, inclusion of corn oil to achieve a concentration of 3.3% linoleic acid in lactation diets did not improve performance during lactation or subsequent reproductive performance of sows.
• Supplementation of lactating sows with linoleic acid (from corn oil) decreased total antioxidant capacity in serum and vitamin E concentrations in serum and milk
• Supplementation of lactating sows with a commercial antioxidant blend increased serum vitamin E concentrations
• Supplementation of linoleic acid (at 3.3%) to lactating sows did not improve lactation performance or subsequent reproductive performance
• Supplementation of a commercial antioxidant blend to sows during lactation did not improve lactation performance or subsequent reproductive performance.
Eric van Heugten
North Carolina State University
Raleigh, NC 27695-7621
Phone: (919) 513 1116