In order to investigate the effects of electrical stunning on slaughter stress and post-slaughter meat quality in pigeons, meat-type pigeons aged 28 days under the same feeding conditions were chosen and subjected to electrical stunning with different voltages (50–90 V) before slaughter (0 V as control), and blood biochemical indexes and meat quality indexes were determined after slaughter. Results showed that the postmortem blood levels of creatine kinase (CK), adrenocorticotropic hormone (ACTH) and lactate dehydrogenase (LDH) in pigeons with electrical stunning decreased compared with those in the control group without electrical stunning, and reached the lowest value at an electrical voltage of 60 V. The blood corticosterone (CORT) concentration firstly decreased and then increased with the increase in stunning voltage, and was significantly higher at voltages greater than 70 V than in the control group, indicating increased stress levels at slaughter. Electrical stunning had no significant impact on the postmortem pH of breast meat. Compared with the control group, the brightness value (L*) of pigeon breast meat at 24 h after slaughter slightly decreased while the redness value (a*) increased. The drip loss, cooking loss and shear force of pigeon breast meat were relatively low at voltages of 60–70 V, suggesting good water-holding capacity and tenderness. In conclusion, electrical stunning at 60–70 V can effectively reduce the slaughter stress and improve the meat quality of pigeons after slaughter, which is beneficial for the welfare slaughter of meat-type pigeons.

In this research, heme iron from meat-type pigeon blood was extracted by enzymatic hydrolysis using papain, neutral protease, alkaline protease, flavourzyme or protamex. Based on heme iron content, papain and protamex were selected for dual-enzymatic hydrolysis. Employing one-factor-at-a-time (OFAT) method and orthogonal array design (OAD) with heme iron content and hydrolysis degree as evaluation indicators, the optimum extraction conditions were determined as follows: papain-to-protamex ratio 2:1, pH 7.0, temperature 50 ℃ , blood-to-water ratio of 1:2, enzyme dosage 8000 U/g, and hydrolysis time 3 h. Under these conditions, the extraction yield of heme iron was 95.43 μg/mL, which was significantly increased compared with that obtained using single enzymes.