Seasonal variation in polyunsaturated fatty acid content of retail whole milk, g/100 g, 18 monthly averages ± SE.

<p>A: Linoleic acid (LA, ω-6). B: α-linolenic acid (ALA, ω-3). C: Conjugated linoleic acid (CLA). The number of monthly samples in all panels is 10 to 13 for organic and 7 to 10 for conventional milk, except 5 conventional in October 2011. For LA and ALA, all differences between organic and conventional contents are statistically significant by Mann-Whitney test (<i>P</i><0.02).