Mulberry leaf powder regulates antioxidative capacity and lipid metabolism in finishing pigs

Yingying Liu; Yinghui Li; Yi Xiao; Yinglin Peng; Jianhua He; Chen Chen; Dingfu Xiao; Yulong Yin; Fengna Li

doi:10.1016/j.aninu.2020.08.005

Mulberry leaf powder regulates antioxidative capacity and lipid metabolism in finishing pigs

Anim Nutr. 2021 Jun;7(2):421-429. doi: 10.1016/j.aninu.2020.08.005. Epub 2020 Dec 18.

Authors

Yingying Liu^{1

2

3}, Yinghui Li¹, Yi Xiao¹, Yinglin Peng³, Jianhua He¹, Chen Chen³, Dingfu Xiao¹, Yulong Yin^{2

4}, Fengna Li²

Affiliations

¹ College of Animal Science and Technology, Hunan Agricultural University, Changsha, 410128, China.
² Key Laboratory of Agro-ecological Processes in Subtropical Region, Hunan Provincial Engineering Research Center of Healthy Livestock and Poultry, and Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China.
³ Hunan Institute of Animal and Veterinary Science, Changsha, 410131, China.
⁴ Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, China.

Abstract

This study evaluated the potential of mulberry leaf powder as an unconventional feed material for finishing pigs by assessing the growth performance, antioxidative properties, fatty acid profile, and lipid metabolism in 180 Xiangcun black pigs. Pigs with an initial body weight (BW) of 71.64 ± 1.46 kg were randomly assigned to 5 treatment groups, including the control diet and 4 experimental diets. The corn, soybean meal, and wheat bran in the control diet were partly replaced by 3%, 6%, 9%, or 12% mulberry leaf powder in experimental diets. There were 6 replicates (pens) of 6 pigs per replicate in each treatment. Blood and muscle samples were collected after the 50-day feed experiment. Compared with the control group, the 3%, 6%, and 9% mulberry diets had no adverse effect (P > 0.05) on the growth performance of pigs. The serum glutathione peroxidase activity and glutathione concentration increased linearly (P < 0.05) with the increase in dietary mulberry inclusion. There was no significant difference in the relative expression levels of antioxidant-related genes in muscle tissue between the control and mulberry groups. Inclusion of dietary mulberry powder increased (P < 0.05) the content of polyunsaturated fatty acids, especially in the longissimus dorsi (LD) muscle, up-regulated (P < 0.05) the relative mRNA expression level of uncoupling protein-3 in muscle tissue, but down-regulated (P < 0.05) the relative mRNA expression levels of hormone-sensitive lipase, acetyl CoA carboxylase α, lipoprotein lipase, and peroxisome proliferator-activated receptor γ in LD in a linear pattern. The nuclear respiratory factor 2 expression level in the LD muscle of pigs fed the 9% mulberry diet was higher (P < 0.01) than that in the other mulberry groups and control group. The inclusion of less than 12% dietary mulberry did not detrimentally affect the growth performance of Xiangcun black pigs, but enhanced the serum antioxidant property, increased the polyunsaturated fatty acid content, and inhibited lipid oxidation by regulating gene expression levels of lipid metabolism and mitochondrial uncoupling protein in muscle tissue. Mulberry leaves can be utilized as a forage crop in the diet of finishing pigs.

Keywords: Antioxidative capacity; Fatty acid; Lipid metabolism; Mulberry; Xiangcun black pig.