Daily oxygen supplementation to the incubator at different stages of embryonic development alters the activity of antioxidant enzymes in the lung tissue of broiler chicks at a high altitude

ABSTRACT

1. Pulmonary hypertension, associated with mitochondrial function in the lung tissue of broilers, can occur at hypoxic high altitudes. The present research examined the impacts of O₂ supplementation at different embryonic stages on broiler organ development and antioxidant enzyme activities.

2. In total, 360 eggs from Ross 308 broiler breeders at sea level were divided into a control group (O₂ non-supplementation group) and three experimental groups daily 1 h 23.5% O₂ supplementation from days 0 to 11 (O_0-11), from days 12 to 21 (O_12-21), and from days 18 to 21 (O_18-21) of embryonic age.

3. The lung, heart, right ventricular (RV), and left ventricular (LV) + septum of newly hatched and seven day old chicks from every group were dissected and weighed. Antioxidant enzyme activities were examined in their lung tissue.

4. The lung weight did not change in any group. At hatching, the heart weight (g and %) was higher in the O_12-21 and O_18-21 groups than in the O_0-11 and control groups, but the relative heart weight was the highest in the O_18-21 group in comparison with the O_12-21 group.

5. Superoxide dismutase (SOD) activity increased in all experimental groups at both ages, but glutathione peroxidase (GPx) activity increased only in seven day old chicks. Catalase (CAT) exhibited high activity in the O_12-21 and O_18-21 groups at hatching. In the seven day old chicks, while the CAT activity did not change in the O_18-21 group, it decreased in the O_0-11 group and increased in the O_12-21 group.

6. Glutathione reductase (GR) activity did not change in the O_18-21 group, but GR exhibited low activity in the O_0-11 group and high activity in the O_18-21 group in newly hatched chicks. The GR activity only decreased in the O_18-21 group of seven day old chicks.

7. The results indicated that oxygen supplementation to the incubator caused alterations in the antioxidant enzyme activities in the lungs of broiler chicks, and this may have been in response to oxidative stress.

KEYWORDS:

• Antioxidant enzymes
• antioxidative defence
• broiler chick
• organ development
• oxygen supplementation

Supplemental data

Supplemental data for this article can be accessed here.

Authors’ contributions

All authors have substantially contributed to the project. The experiments were conceived and designed: E.B and U.G. Broiler chicks were reared and tissues were dissected: E.B Activities of antioxidant enzymes were assayed: U.G. The data were analysed: E.B and U.G. Article was prepared: E.B and U.G. All authors have reviewed and approved the final article before submission.

Disclosure statement

The authors declare no conflicts of interest.

Ethics statement

The study was carried out following the ethical approval obtained from Van YYU University. All animal care and procedures were performed according to the ethical principles of animal use and care (European Community Council Directive 86/609/EEC on the Protection of Animals Used for Experimental and Other Scientific Purposes, 1986).

Software and data repository resources

Data and models utilized in the present research are not deposited in an official repository.

Additional information

Funding

The study was funded by Van Yuzuncu Yil University, Scientific Research Projects Coordinator (Project ID number : 2014-ZF-8222).