Effects of catechins on litter size, reproductive performance and antioxidative status in gestating sows

摘要

Abstract This study was conducted to investigate the effects of catechins on reproductive performance, antioxidative capacity and immune function of gestating sows. A total of 60 cross-bred (Landrace?×?Large White) multiparious sows were blocked by body weight, parity and backfact and randomly allocated to 1 of 5 treatments: 0, 100, 200, 300, or 400?mg/kg catechins. Dietary treatments were imposed from mating to d 40 of gestation of sows. At farrowing, litter total born, born alive, dead, and normal-(healthy piglets, ≥0.85?kg) and low-birth weight piglets (2O₂), nitric oxide synthetase (NOS) and nitrogen monoxide (NO). Our results showed that supplementation of catechins at levels of 200 or 300?mg/kg led to improvements in litter born alive ( P ?0.05). Sows received 200?mg catechin per kg diets showed a reduction ( P 2O₂ level compared with sows received the control diet on both d 40 of gestation and farrowing. Our results demonstrated that the catechins may be a potential antioxidant to increase the reproductive performance and antioxidative capacity of sows when it was added into diets during the early gestation. Keywords Antioxidative capacity ; Catechins ; Gestating sows ; Litter size ; Reproductive performance prs.rt("abs_end"); 1. Introduction Rapid fetal development during the gestation led to a catabolic status of pregnant women or dams which is known to contribute to the production of excessive free radicals including superoxide and hydrogen peroxide and the induction of systemic oxidative stress ( Herrera and Ortega-Senovilla, 2010 and Kim et?al., 2013 ). Increased oxidative stress was reported to be an important factor causing decreased availability of antioxidants during late gestation, which could impaired placenta and fetal growth ( Prater et?al., 2008 ) and trigger a disrupted antioxidant system that was involved in a variety of pregnancy complications such as preterm labor, fetal growth restriction, preeclampsia and miscarriage ( Gupta et?al., 2003 and Sugino et?al., 2007 ). This elevated oxidative stress during gestation and lactation was likely to influence not only the litter performance,?but also the well-being and health status of sows including?impaired milk production, reproductive performance, and longevity ( Agarwal et?al., 2003 , Jabbour et?al., 2009 , Zhao et?al., 2011 and Zhao et?al., 2013 ). Therefore, much attention has been paid to how to reduce maternal oxidative stress levels and inflammatory responses of highly prolific sows in late gestation by feed antioxidant additives. In numerous previous studies, antioxidants such as vitamin E, vitamin C, carotenoids, and selenium ( Lykkesfeldt and Svendsen, 2007 ), fish oil and olive oil ( Shen et?al., 2015 ) and soy isoflavones ( Hu et?al., 2015 ) were added into the diet during gestation period in order to compensate for the substantial loss of these feed antioxidant additives. Excessive reactive oxygen and radical were actually produced from placental and maternal metabolism during the early pregnancy of sows. Although oxidative stress in late gestation was more serious than that in early gestation with the course of pregnancy ( Berchieri-Ronchi et?al., 2011 , Casanueva and Viteri, 2003 and Myatt and Cui, 2004 ), indicating that early pregnancy may be a key phase for prevention of oxidative damage. Catechins?are members of the flavonoid family and belong to plant polyphenolic constituents ( Uzun et?al., 2010 ), which are not only existing in a high concentration within tea, but also present in many foods, such as apples, grapes, vine and their processed beverages ( Tichopad et?al., 2005 and Suzuki et?al., 2007 ). Previous studies showed that catechins has a certain degree of hydrophobicity and can capture the OH?1, which protect the DNA from the oxidant damage ( Yoshioka et?al., 1996 ); And catechins also alleviated the damage by up-regulating the expression of genes of some antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) so that increase those enzyme's production and activity ( Mkimura et?al., 2002 ). Previous studies showed that catechins prevented metal ions from participating in peroxidase reactions by binding them and had the potential to scavenge reactive oxygen and nitrogen species, thus?reducing their damage to lipid membranes, proteins, and nucleic acids in cell-free systems ( Wiseman et?al., 1997 ). These findings indicated that catechins prevented metal ions from participating in?peroxidase reactions by binding them and had the potential to?scavenge reactive oxygen and nitrogen species ( Wiseman et?al., 1997 ). It was reported that catechins administration significantly decreased malondialdehyde (MDA) level and noticeably increased?activities of CAT, GSH-Px and SOD, suggesting that catechins?provided effective protection from oxidative damages through their antioxidant properties ( Tarek et?al., 2012 ). Therefore, it is