| Transportation is an important link in animal husbandry,but in the process of transportation,animals often suffer from stress reaction,resulting in direct or indirect economic losses.Adding vitamin C in drinking water and fasting after transportation are commonly used methods to alleviate transport stress in rabbit breeding.At present,there are few studies on the anti-transport stress mechanism of vitamin C and fasting.Therefore,our study aims to explore the effects of adding vitamin C in drinking water and fasting on serum biochemical indicators,hormone levels and inflammatory factors in rabbits after transportation,as well as the meat quality,expression of apoptotic genes in liver and behavior,provide theoretical reference for these two anti-stress methods.Experiment 1:80 male rabbits weighing about 2.5 kg were randomly divided into 8groups:control group,0 h after transportation group,6 h fasting group,24 h fasting group,6 h non-fasting group,24 h non-fasting group,fasting behavior observation group and non-fasting behavior observation group,with 10 rabbits in each group.The rabbits were fed adaptively for 7 days after being transported to the farm.On the eighth day,except the control group,the rabbits in the other groups were loaded in transport cages and then returned to the rabbit farm after being transported by truck for 2 hours.After transportation,the fasting group fasted and drank water freely,the non-fasting group ate and drank water freely,slaughtered the corresponding group of meat rabbits at 6 and 24hours respectively,while the behavior observation group did not slaughter.Serum,liver and muscle tissues were collected after slaughter,and the behavioral changes of the rabbits were recorded by camera.The results showed that:(1)Compared with the control group,the concentration of cortisol in serum of rabbits in 0 h after transportation group increased significantly(P<0.05).(2)Compared with the control group,the concentration of IL-1beta in serum of rabbits after transportation was significantly lower(P<0.05),while the concentration of TNF-?in serum of 6 h fasting group was significantly lower than that of other groups(P<0.05).(3)The concentration of CK in the 24 h fasting group was significantly higher than that in the other groups(P<0.05),and LDH in the 6 h fasting group was significantly higher than that in the other five groups(P<0.01).(4)Compared with the control group,the pH value of the longissimus lumborum muscle of the rabbits in each group increased significantly after transportation(P<0.05).The L~*value of the longissimus lumborum muscle of rabbits in the 0 h after transportation group,6 h group and 24 h fasting group decreased significantly(P<0.05).The muscle a~*values of 6 h fasting group,6 h non-fasting group and 24 h fasting group were significantly lower than those of control group(P<0.05),while the muscle a~*values of 0 h after transportation group were significantly lower than those of other groups(P<0.01).The b~*value of muscle in 6 h fasting group,6 h non-fasting group and 24 h fasting group was significantly lower than that in control group(P<0.05).(5)The relative expression of JNK in liver of control group was significantly lower than that of other groups(P<0.05).And the expression of Caspase-3 in liver of 0 h after transportation group was significantly higher than that of control group(P<0.05).6 hours and 24 hours after transportation,there was no significant difference between fasting group and non-fasting group(P>0.05).(6)The time proportion of coprophagy of rabbits in fasting group after transportation was significantly higher than that in non-fasting group(P<0.05)?Experiment 2:60 rabbits weighing about 2.5 kg were randomly divided into six groups:VC 6 h group,VC 24 h group,non-VC 6 h group,non-VC 24 h group,VC behavior observation group and non-VC behavior observation group,with 10 rabbits in each group.After the rabbits were transported to the farm,they were fed adaptively for 7days.In the VC group,2.5 mg/L of VC was added into the drinking water.On the eighth day,except the control group,the rabbits in the other groups were loaded in transport cages,and then transported by trucks for 2 hours.Free access to water and fasting after transportation.Rabbits in VC 6 h group,non-VC 6 h group,VC 24 h group,and non-VC24 h group were slaughtered at 6 h and 24 h after transportation,respectively,while the behavior observation group did not slaughter.Serum,liver and muscle tissues were collected after slaughter,and the behavioral changes of the rabbits were recorded by camera.The results showed that:(1)The interaction between VC and time had no significant effects on serum cortisol,TNF-?and IL-1?concentrations(P>0.05).Compared with VC 6 h group,the cortisol concentration in serum of non-VC 6 h group and non-VC 24 h group increased significantly(P<0.05).(2)The concentration of ALT,CK and TP was significantly affected by adding VC(P<0.01).The interaction between VC and time had significant effects on serum Glu concentration(P<0.05).Compared with VC 6 h group,CK concentration in non-VC 6 h group increased significantly(P<0.01).(3)The concentration of TNF-?was significantly affected by adding VC(P<0.05),and the concentration of TNF-?was significantly affected at different time after transportation(P<0.01).The concentration of TNF-a in serum of rabbits in VC 24 h group was significantly lower than that in non-VC 24 h group(P<0.05).(4)Adding VC had significant effects on muscle L~*value(P<0.01).Different time after transportation had significant effects on muscle pH,L~*value,a~*value and b~*value(P<0.01).The interaction between VC and time had significant effects on muscle pH(P<0.05),and had significant effects on L~*value(P<0.01).24 hours after slaughter,the pH value of longissimus lumborum muscle in VC 6 h group was significantly higher than that in non-VC 6 h group(P<0.05).(5)The time ratio of sitting of rabbits in VC group after transportation was significantly higher than that in non-VC group(P<0.01),and the frequency or time ratio of eating and movement was significantly lower than that in non-VC group(P<0.01).Our results showed that fasting could change the meat quality of rabbits after transportation,increase the duration of stress response and increase the activity of rabbits.The addition of VC in drinking water could reduce the activity of meat rabbits after transportation and delay the decline of meat quality after slaughter. |
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