Effect of copper nanoparticles and copper sulphate on metabolic rate and development of broiler embryos

Highlights

• Recently, it has been reported that in ovo injection of copper nanoparticles (Cu-NP) positively influences chicken performance.

• In the present paper we have evaluated effects of Cu-NP and CuSO4 administration on embryo development and metabolic rate.

• The in ovo administration of Cu-NP increased the metabolic rate of embryos, which might be a partial explanation for their long-lasting effects on chicken performance.

• However, Cu-NP did affect body and organ weight and chosen biochemical and molecular parameters.

Abstract

Copper (Cu) is regularly used as a growth promoter in poultry production. However, it has been demonstrated that the content of Cu inside eggs might not be sufficient to support the embryonic development. It is possible to supply the embryo with extra nutrients by in-ovo administration. Recently, it has been shown that in-ovo administration of copper nanoparticles (Cu-NP) and copper sulphate (CuSO₄) remarkably improved the body weights of growing chickens. Thus, the objective of the present experiment was to elucidate the potential effects of Cu-NP and CuSO₄ on the metabolic rate (oxygen consumption — O₂ and energy expenditure — EE) and development during embryogenesis.

Fertilised broiler eggs were divided into six groups: a non-injected control, a placebo injected with demineralised water, two groups injected, at day one of incubation, with CuSO₄ (50 and 100 mg/kg) and two groups injected with Cu-NP (50 and 100 mg/kg). Gaseous exchange was measured in an open-air-circuit respiration unit, and EE was estimated from day 10 to day 19 of embryogenesis. Body weight at 24 h after hatching and the relative organ weights were used as a measure of hatching development. In-ovo injection of 50 mg/kg Cu-NP and CuSO₄ significantly increased O₂ consumption and EE on the 16th and 19th day of incubation compared with the control group; Cu-NP had the largest effect on the metabolic rate. However, organ weights (intestine, heart, liver, and breast) relative to the yolk-free body weight were not affected in the injected groups. In addition, blood parameters did not show any changes among the groups. This result demonstrates that in-ovo injection of Cu-NP affects the metabolic rate of embryos, which might explain their improved performance after hatching.

Keywords: Embryo; Growth promoter; Gene expression; Metabolic rate; Nanoparticles.

Abstract published in Animal Feed Science and Technology, Volume 220, 2016, Pages 151-158, ISSN 0377-8401. https://doi.org/10.1016/j.anifeedsci.2016.08.009.