Effects of maternal dietary manganese and incubation temperature on hatchability, antioxidant status, and expression of heat shock proteins in chick embryos1

Abstract

To investigate whether supplementing manganese (Mn) to the maternal diet could reduce the deleterious effect of heat stress on the developing embryo, the hatchability, antioxidant status, and expression of heat shock proteins (HSP) were evaluated in chick embryos under normal and high incubation temperatures. A completely randomized design ( = 6) with 2 maternal dietary Mn treatments (unsupplemented control basal diet versus the basal diet + 120 mg Mn/kg as inorganic Mn) × 2 incubation temperatures (normal, 37.8°C, versus high, 39.0°C) was used. High incubation temperature did not affect ( > 0.19) hatchability and embryo mortality and development but did increase ( < 0.05) activities of heart manganese superoxide dismutase (MnSOD) and liver copper zinc superoxide dismutase and liver MnSOD mRNA and protein levels in embryos. High incubation temperature also decreased ( < 0.003) HSP70 protein level in the heart but had no effects ( > 0.07) in the liver of embryos. Maternal diet with Mn supplementation not only increased ( < 0.05) the hatchability and Mn content ( < 0.001) in the yolk and embryonic tissues and the activity of MnSOD in the heart ( < 0.004) as well as relative liver weight ( < 0.05) under normal incubation temperature but also decreased ( ≤ 0.05) embryo mortality and HSP90 mRNA level in the liver and heart of embryos. Furthermore, under high incubation temperature, maternal diet Mn supplementation increased ( < 0.002) MnSOD protein expression in the liver of embryos but had no effect ( > 0.43) under normal incubation temperature. These results indicated that high incubation temperature induced self-protective responses of chick embryos with a modification of antioxidant status and a depression of HSP70 protein level. Maternal dietary supplementation of Mn could improve the hatchability as well as antioxidant ability to protect against heat challenge in embryos during incubation.

The chemical characteristics of organic iron sources and their relative bioavailabilities for broilers fed a conventional corn–soybean meal diet1

“…The birds were subsequently killed; samples of their liver, kidney, and heart were taken; and a subsample was frozen at −20°C for the analyses of Fe content and catalase (cAT) and succinate dehydrogenase (sDH) activities and another sample was frozen in liquid N for CAT and SDH gene expression assays. The samples of the liver, kidney, and heart were homogenized with a tissue grinder (T 18 D S25; IKA Group, Staufen, Germany) in ice-cold 10% (wt/vol) physiological saline for 1 min and then treated with an ultrasonic wave cell grinder (JY92-11; Ningbo Scientz Biotechnology Co., Ltd., Ningbo, Jiangsu, P. R. China) for 1 min (1 s, with 2-s interval) as described by Zhu et al (2015). Then, the homogenates were centrifuged at 1,000 × g for 15 min at 4°C to harvest the supernatants for immediately analyzing total protein content and CAT and SDH activities.…”

“…The primers for CAT, SDH, β-actin (housekeeping gene), and glyceraldehyde3phosphate dehydrogenase (GAPDH) gene (housekeeping gene) were chosen with Primer Express software (Applied Biosystems Inc., Foster, CA) and their information is summarized in Table 3. The β-actin and GAPDH genes were used to normalize the expressions of targeted genes CAT and SDH mRNA using the 2 −ΔΔCT method (Livak and Schmittgen, 2001;Zhu et al, 2015).…”

Maternal dietary manganese protects chick embryos against maternal heat stress via epigenetic-activated antioxidant and anti-apoptotic abilities

“…To address the roles of the maternal dietary inorganic and organic Mn sources in the development of offspring embryos from the heat stressed broiler breeders as well as the deep mechanisms involved, the related data (see the captions in Figures 1 – 4 and Supplementary Figure 1 ) collected from chick embryos delivered from the control broiler breeders in our previous published study [ 31 ] were used for statistical analyses in the present study. The previous study [ 31 ] was conducted at the same time and facility as this study, and the broiler breeders raised at the normal temperature with a Mn-unsupplemented diet or the basal diet supplemented with the inorganic Mn were treated as the control maternal groups for the present study in accordance with the requirements of the Animal Welfare Committee of the Institute of Animal Science, Chinese Academy of Agricultural Sciences.…”

“…Yolk ( D ) and liver ( E ) Mn contents were measured based on fresh basis. The data of Mn contents in yolk and liver from the M-CON and M-iMn groups under M-NT as the control groups in the present study have been published in our previous study [ 31 ]. Based on the 2-way ANOVA analyses, “ * ” means significant differences at P < 0.05 between M-NT ( n = 18) and M-HT ( n = 18) as determined by a main effect of maternal environmental temperature; lacking common letters (a, b or c) means significant differences at P < 0.05 between grouped bars (maternal dietary Mn sources, n = 12) or between single bars (individual treatments, n = 6) as determined by a main effect of maternal dietary Mn or their interaction.…”

Manganese enhances the expression of the manganese superoxide dismutase in cultured primary chick embryonic myocardial cells

“…Gallup and Norris (1939) reported that Mn deficiency in laying hens caused decreased hatchability and increased mortality of embryos. The recent study from our laboratory has demonstrated that maternal dietary supplementation with Mn could improve hatchability as well as antioxidant ability to protect offspring chick embryos against heat challenge during incubation from the 10th to 18th days of incubation (Zhu et al 2015b). Therefore, supplementation with Mn in laying hen diets can be an alternative way to protect cells from oxidative stress during the chick embryonic development.…”