It has been well documented that n-3 polyunsaturated fatty acids (n-3 PUFA) can alleviate inflammation caused by () lipopolysaccharides (LPS), the etiologic agents that causing yellow or white dysentery in young pigs. However, it remains unclear whether the increase in n-3 PUFA availability could enhance the ability of nursery pigs to resist invasion by . LPS. Twenty-four 21-day-old female piglets, each two of them from the same sow fed the beef tallow (BT) or fish oil (FO) diets, were allocated into four treatment groups: BT-CON, piglets from the BT-fed sows and intraperitoneally injected with saline (9 g/L); BT-LPS, piglets from the BT-fed sows and injected with LPS (100 μg/kg body weight); FO-CON, piglets from the FO-fed sows and injected with saline; FO-LPS, piglets from the FO-fed sows and injected with LPS. Following 2 h of LPS challenge, the magnitudes of increase in body temperature approached to a marked ( 0.01) difference between the BT-CON and BT-LPS piglets, whereas the dramatic ( 0.01) difference between the FO-CON and FO-LPS piglets was only observed at 4 h post LPS challenge. The body temperature averaged across the time points evaluated was about 0.2°C lower ( 0.05) in the FO group than in the BT group. The FO group had lower ( 0.05) mean corpuscular hemoglobin concentration, lower increase in serum interleukin (IL)-1β ( < 0.10) and IL-8 ( 0.05) levels, higher ( 0.01) serum albumin concentration, and higher ( = 0.10) ratios of jejunum villus height to crypt depth than the BT group. The FO group had much higher ( 0.0001) ileal content of C20:5n3, C24:0, and C22:6n3, which were 2-4 times the content of the BT group. LPS challenge resulted in decreased ( 0.05) intestinal C20:1 and C20:5n3 content, and the decrease ( 0.05) in intestinal C20:3n6 and C24:1 content was observed in the BT-LPS piglets rather than in the FO-LPS piglets. Taken together, this study indicated that maternal consumption of fish oil protected breast-fed piglets against LPS-induced damage through reshaping of intestinal fatty acids profile, which sheds new light on the development of nutritional strategies to enhance the ability of young pigs to resist invasion.