Effects Of Pre-slaughter Treatment On Stress And Meat Quality Of Yellow Chickens

In order to prevent the emergence of large-scale and a wide range of flu epidemic,the government is implementing scale and standardized slaughter of yellow chickens.Therefore,it is helpful to improve the market acceptance of chilled chicken in discussioning on the improvement of yellow chickens stress and chicken quality during the slaughter of yellow chicken.In this paper,the effects of acute showering time,hanging time and the illumination intensity of hanging room on the stress physiological and biochemical indexes and meat quality of yellow chickens were studied.The mechanism was discussed in order to study the mechanism of yellow chickens,improve animal welfare and chicken quality,and for the yellow chickens concentrated slaughtering process to provide improvement measures and theoretical support.The main result are as follows:1,In summer,in Southern C hina,acute shower was used to clean and cool the yellow chickens before slaughter.During acute showering,in this experiment,the stress response of yellow chickens was increasing from 0 to 10 min,15 ~ 20 min into the fatigue period,the best quality of chicken was showered to 15 min.There was no significant difference to the control groupin the leaching time(35 ± 4 s)and the levitation amount(36.01 ± 3.11 g)at 15 min(p > 0.05),but significantly higher than that of the other experimental group(p<0.05);the broken bone was the lowest(4.2 ± 0.1)% at 15 min;45 minutes after slaughter,the muscle glycogen content of breast(3.54 ± 0.11 mg / g tissue)and leg(2.93 ± 0.06 mg / g)were significantly lower than showered to 5 min and 10 min;and p H 24h(6.08 ± 0.05)was significantly larger than that in showered to 20 min;24 h breast drop loss rate(4.54 ± 0.11)and cooking loss rate(15.89 ± 0.24)was no significant difference to the control group,showered at 15 min,breast elasticity(0.83±0.05)and leg elasticity(0.69 ± 0.04)was significantly higher than that in the control group a nd other experimental groups(p<0.05).That was,the optimal time for the acute shower before slaughter is 15 min,the yellow chickens is the least stress,the chicken quality is the best.2,In commercial processing,stunned before the hanging is inevitable,but there is no uniform time hanging standard.In this experiment,it was found that during the period of 120 s hanging,the initial stress was the strongest,and then entered into the relaxation period,after 60 s,it entered the fatigue period.Hanging to 60 s,Adrenocorticotropichormone ACTH content in plasma was(171.53 ng / L),and plasma corticosterone hormone CORT content was(5.47 ng / mL)were significantly lower than those in the control group and other experimental groups(p<0.05).The muscle glycogen content of breast muscle(3.76 ± 0.07 mg / g tissue)was significantly lower control group;breast elasticity(0.67 ± 0.04)and hardness(143.24 ± 24.26 g)were lower than the other experimental group.That is,the best hanging time is 60 s.3,Yellow chickens is more sensitive to light,the current concentration of slaughtering production line the illuminance value of the hanging room has no uniform standard.In this experiment,the light intensity was in the range of 10 ~ 210 lx,stress response is more slow in low illumination value,and the high illumination value was not easy to gentle.The self-regulation time of the broiler was long and the quality of the chicken was deteriorated.When the illumination value is 60 lx,the alert latenc y(1.1 ± 0.1 s)was significantly higher than that other experimental groups;the shear stress(50.90 ± 1.89 N)of brest muscle at 24 h after slaughterwas significantly higher than the other experimental groups.Therefore,useing less than 60 lx of the illumination value can reduce the chicken stress,improve the quality of chicken.The main way of feed ing is free in the process of yellow broilers,tolerance to environmental stress is better than feeding in the cage broilers.The results showed that the acute shower time of the yellow chickens was 15 min and the hanging time was 60 s,hanging room light illumination value of less than 60 lx.