Juniper D T, Kliem K E, Lee A, Rymer C
Department of Animal Sciences, School of Agriculture, Policy and Development, University of Reading, Reading RG6 6AR, UK.
Department of Animal Sciences, School of Agriculture, Policy and Development, University of Reading, Reading RG6 6AR, UK.
Animal. 2022 Mar;16(3):100459. doi: 10.1016/j.animal.2022.100459. Epub 2022 Feb 23.
Selenium (Se) plays a crucial role in protecting biological materials from oxidative damage through the action of the selenoprotein glutathione peroxidase (GSH-Px), and the effectiveness of this protection is often dependent upon Se supply. Recent evidence has indicated that GSH-Px mRNA expression can be upregulated in response to potential oxidative damage risk, and that this upregulation is independent of Se supply. The current study aimed to determine the effect of Se supplementation, stocking rate and tissue fatty acid profile on GSH-Px activity in breast and thigh tissue of commercial broilers. A total of 168 Ross 308 broiler chicks were enrolled onto the study. Prior to enrolment, birds were brooded as a single group and received a starter diet containing no additional Se. The study was a 2 × 2 factorial design comprising of two levels of dietary Se (high Se, 0.5 mg/kg total Se, low Se background Se only), and two stocking rates (high, 30 kg/m, and low, 15 kg/m). At 15 days of age, birds were blocked by live weight and randomly allocated to one of the four treatments, with six pen replicates per treatment. At 42 days of age, one bird was randomly selected from each pen replicate, euthanased and breast and thigh tissue harvested. GSH-Px activity, thiobarbituric acid reactive substances (TBARS), and fatty acid (FA) content of these tissues were determined. There was no effect (P > 0.05) of stocking rate on GSH-Px activity or TBARS. GSH-Px activity did not differ between tissue types but was greater in high Se birds (P < 0.001) compared to low Se. TBARS concentrations were greater in thigh tissue (P < 0.001), and these thigh concentrations were greater in high Se birds (P < 0.05). There were marked differences between breast and thigh tissue in most FAs (P < 0.001), with breast generally containing greater proportions of polyunsaturated FA, so that breast tissue had a higher (P < 0.001) peroxidisability index (PI) than thigh. A positive correlation between GSH-Px activity and PI in the thigh tissue of high Se birds (Pearson Correlation 0.668; P = 0.025) may indicate that increasing susceptibility to peroxidisation in lipid-rich tissues may also upregulate GSH-Px activity in Se-replete birds. This study suggests that ensuring adequate dietary selenium could be a useful tool to mitigate adverse effects on meat quality caused by oxidation, particularly in lipid-rich meat.
硒（Se）通过硒蛋白谷胱甘肽过氧化物酶（GSH-Px）的作用，在保护生物材料免受氧化损伤方面发挥着关键作用，这种保护作用的有效性通常取决于硒的供应。最近的证据表明，GSH-Px mRNA表达可因潜在的氧化损伤风险而上调，且这种上调与硒的供应无关。本研究旨在确定补充硒、饲养密度和组织脂肪酸谱对商品肉鸡胸部和大腿组织中GSH-Px活性的影响。共有168只罗斯308肉鸡雏鸡参与了本研究。入组前，将鸡作为一个单组进行育雏，并给予不含额外硒的起始日粮。本研究采用2×2析因设计，包括两个日粮硒水平（高硒，总硒0.5mg/kg，低硒仅为背景硒）和两个饲养密度（高，30kg/m²，低，15kg/m²）。在15日龄时，根据体重对鸡进行分组，并随机分配到四种处理中的一种，每个处理有六个栏重复。在42日龄时，从每个栏重复中随机选取一只鸡，进行安乐死，并采集胸部和大腿组织。测定这些组织的GSH-Px活性、硫代巴比妥酸反应性物质（TBARS）和脂肪酸（FA）含量。饲养密度对GSH-Px活性或TBARS没有影响（P＞0.05）。GSH-Px活性在不同组织类型之间没有差异，但高硒组鸡的GSH-Px活性高于低硒组（P＜0.001）。大腿组织中的TBARS浓度更高（P＜0.001），且高硒组鸡大腿组织中的TBARS浓度更高（P＜0.05）。大多数脂肪酸在胸部和大腿组织之间存在显著差异（P＜）。
