Effects of dietary supplementation of different amounts of yeast extract on oxidative stress, milk components, and productive performance of sows

•Sows fed with the YE diet increased ADFI, and reduced weight loss during lactation.•Amelioration oxidative stress status of sows and their offspring in YE diet group.•Sows treated with YE increased the concentration of milk nucleotides. This study evaluated the effects of different amounts (0, 2.5, 5, 10 g/kg) of dietary yeast extract (YE, including 102 g/kg nucleotides) on the milk composition, oxidative stress status, and performance of sows and their offspring. A total of 80 multiparous Large White sows (2-3 of parity) were allotted to 1 of the 4 dietary treatments (0, 2.5, 5, 10 g/kg YE, with 0 g/kg YE used as control (CON)) based on body weight at day 85 of gestation (n=20 per treatment), and the experiment lasted from day 85 of gestation to day 21 of lactation. The reproductive performance of sows and growth performance of piglets were measured. Blood samples were collected from sows and weaning piglets for measuring the level of oxidative stress parameters. The general composition and nucleotide concentrations of colostrum and milk were also measured. Results indicated that, with increasing YE amount in the diet, sows had a linear increase (P ≤ 0.05) in average daily feed intake (ADFI) during the first week of lactation, while a linear decrease (P ≤ 0.01) in body weight loss during lactation. Additionally, the 10 g/kg YE treatment tended to increase the number of weaned piglets per litter (P = 0.08). Furthermore, with increasing YE, the milk exhibited a linear increase (P < 0.05) in the concentrations of cytidine 5’monophosphate (5’CMP), uridine 5’monophosphate (5’UMP), guanosine 5’monophosphate (5’GMP), inosine 5’monophosphate (5’IMP) and adenosine 5’monophosphate (5’AMP) and total nucleotides. Interestingly, the 10 g/kg YE treatment was higher than the control in serum levels of total antioxidant capacity (T-AOC) (P < 0.05) and glutathione peroxidase (GSH-Px) at day 109 of gestation of sows (P < 0.01) and also at weaning of piglets (P < 0.01), while lower (P < 0.05) for weaning piglets in the serum level of thiobarbituric acid reactive substances (TBARS). Collectively, the 10 g/kg YE treatment was shown to increase the concentration of nucleotides in milk and alleviate the oxidative stress status of both sows and weaning piglets.