Dietary supplementation with a high dose of daidzein enhances the antioxidant capacity in swine muscle but experts pro-oxidant function in liver and fat tissues

Background： Although isoflavones are natural dietary antioxidants, they may have toxicological effects. This study aimed to evaluate the redox system in tissues of finishing pigs by supplementation with high dose of daidzein（640 mg/kg）.Results： The supplementation of high dose of daidzein for 64 d increased the activity of superoxide dismutase and total antioxidant capacity in longissimus muscle but down-regulated the expression of reactive oxygen species（ROS）-producing enzyme NADPH oxidase-2 and cyclooxygenase-2. In contrast, high-level supplementation with daidzein exerted pro-oxidant changes in back fat, abdominal fat, liver, and plasma, as reflected by increased contents of malondialdehyde, a lipid peroxidation product, in these tissues. Furthermore, daidzein supplementation resulted in higher expression of ROS-producing enzymes, including NADPH oxidase-1 and cyclooxygenase-1in liver, 5-lipoxygenase（5-LOX） in backfat and NADPH oxidase-2 both in abdominal fat and backfat. The supplementation of daidzein did not affect meat quality parameters in longissimus muscle, including marbling score,eye muscle areas, intramuscular fat, shear force, drip loss, p H and meat color.Conclusions： This experiment suggests that dietary supplementation of finishing pigs with daidzein at a high dose level improves redox status in muscle but exerts pro-oxidant effect in liver and fat tissues.

Organic practices and gender are effective strategies to provide healthy pork loin

This study evaluated the influence of husbandry（organic feed and management but not free-ranging vs. conventional） and sex（barrows vs. gilts） on pork meat quality. A total of 60 Longissimus thoracis pork muscle samples from different 3-way crossbred genotypes were chosen from 3 conventional and 2 organic pig farms. Technological meat quality was measured at 24 h post-mortem and muscle fatty acid content and composition was analysed by gas chromatography. The loin from organic pigs at 24 h of retail display had lower pH, but it had no detrimental effects on drip loss. All the International Commission on Illumination colour attributes except meat lightness differed between husbandry systems. Moisture and crude protein content were lower whereas intramuscular fat content was greater in organic than in conventional pork. Total saturated fatty acid（SFA）, monounsaturated fatty acid（MUFA）, polyunsaturated fatty acid（PUFA） and PUFA n-6 contents did not differ between husbandry systems, but total PUFA n-3（mainly C18：3 n-3） were greater in organic than in conventional pork. Sex did not affect ultimate p H or meat colour attributes but barrows showed lower moisture and greater intramuscular fat than gilts. Total SFA and MUFA content were similar but all the PUFA（both n-6 and n-3） were lower in barrows than in gilts. These results suggest that some bioactive compounds from dietary origin, i.e., linolenic acid（C18：3 n-3） content from dietary vegetable oils（soybean or olive olein）, might be used to highlight the nutritive value of（not free-ranging） organic pork meat. In addition, gilts were leaner than barrows and showed a more favourable PUFA/SFA ratio.

CRISPR/Cas9 mediated gene editing helps pig fight cold and fat

Supported by the National Natural Science Foundation of China,a research team led by Prof.Zhao Jianguo(赵建国)and Jin Wanzhu(金万洙)from the State Key Laboratory of Stem Cell and Reproductive Biology,Institute of Zoology,Chinese Academy of Sciences and Prof.Wang Yanfang(王彦芳)from