Dietary Laminar iajaponica polysaccharide regulates systemic defence property of weaned piglets improving growth performance under high temperature condition

This study was conducted to evaluate the effect of dietary LJP supplementation on growth performance, heat stress resistance and immune status of weaned piglets raised in a high-temperature environment (34 ± 3°C).

A total of 72 Barkshire * Licha Black crossbred piglets were weaned at 30 days of age (BW, 5.88 ± 0.16 kg) and fed either without or with 100, 200 or 400 mg/kg LJP in a completely randomized design, with 3 pens per diet (6 pigs per pen). On day 21, a total of 12 piglets were selected to collect blood samples.

The results showed that 200 and 400 mg/kg LJP supplementation decreased the feed conversion ratio (FCR) of piglets compared to the control group (P=0.037) and dietary LJP linearly increased average daily gain and decreased FCR of piglets (P=0.037 and 0.011, respectively). In addition, adding 100, 200 and 400 mg/kg LJP reduced the serum HSP70 content compared to the control group (P=0.019) and dietary LJP linearly and quadratically decreased the serum HSP70 content of piglets (P=0.030 and 0.011, respectively). Moreover, supplementation of 200 mg/kg and 400 mg/kg LJP increased the serum (NO) and nitric oxide acid phosphatase (ACP) content compared to the control group (P=0.019; P=0.003) and dietary LJP linearly increased the serum lysozyme, NO and ACP contents (P=0.039; P=0.005; P=0.001). In conclusion, dietary LJP has potential to regulate systemic defence property of weaned piglets raised in a high temperature condition, accompanied by increased growth performance.