Effects of dietary ramie powder at various levels on growth performance, antioxidative capacity and fatty acid profile of finishing pigs

This study was conducted to evaluate the effects of ramie ( Boehmeria nivea , previously known as a fibre crop and also called “China grass”) included in diets on growth performance, antioxidative capacity and muscular fatty acid profile of finishing pigs. A total of 180 Xiangcun Black pigs (initial body weight =70.71 ± 1.21 kg) were randomly allotted to 1 of 5 dietary treatments with six pens of six pigs per pen. The pigs were provided a basal diet or a diet contained 3%, 6%, 9% or 12% of ramie powder during a 50‐day experiment period. The results showed that the inclusion of ramie increased (quadratic, p  < 0.05) the average daily gain (ADG) and gain:feed ratio (G:F) with the highest value of ADG and G:F in 3% ramie group, but ramie content in the diet up to 9% reduced the growth performance of the pigs compared with that of 3% ramie group. The activity of serum total superoxide dismutase (SOD) was increased (linear, p  < 0.05) by ramie, while content of malondialdehyde was decreased (linear, p  < 0.05). As increasing the dietary ramie level, the mRNA expression level of SOD1 was increased quadratically ( p  < 0.05) in muscle tissues. Moreover, the addition of ramie linearly increased ( p  < 0.05) polyunsaturated fatty acids content, whereas it linearly reduced ( p  < 0.05) the lipid indices of atherogenicity (AI) and thrombogenicity (TI) in muscle tissues, and lower values of AI and TI reflect a “healthier” fat composition. The results indicated that ramie in a diet not more than 9% may improve antioxidative capacity with no detrimental impact on growth performance of Chinese native finishing pigs; meanwhile, it could beneficially change the pork fatty acid pattern which has a positive impact on consumer's health.