Effects Of Feeding Restriction Patterns On Production Performanceandcarcass Quality Of Meat Duck

Two experiments were conductedto investigate the effects of different restrictedfeeding patterns on the productive performance and carcass quality of meat ducks,providing data support and theoretical basis for scientific and rational use ofrestricted feeding patterns in production.Exp.1 Preliminary study oneffects of different feeding restrictionpatterns on the performance and caraccas quality of meat duck.This study was to investigate the effects of different restrictedfeedingpatternsontheproductive performance and carcass quality of meat ducks,and selected the most suitable pattern in combination with economic benefit.520Cherry-Valley ducks(female ducks)were fed the same basic diet for 10 d,and were divided into 4 treatment groups on 11 d according to the principle of no difference in initial body weight.Treatment 2,3,4 with 8 replicates and 13 ducks each replicate.Treatment 1 was the control group(the current restricted feeding pattern in commercial production,free feeding at 11-39 d,restricted feeding at 40-48 d,250 g/ bird /2 d);Treatment 2 and treatment3 were free feeding for 6 h,30-39 d and 40-48 d,respectively,depending on body weight.Treatment 4 free feeding for 8 h at 21-30 d,free feeding at 30-39 d,and restricted feeding at 40-48 d according to body weight.The trial lasted 38 days.Productive performance and carcass quality indicators were examined on the 49 th day.The results showed :1)Productive performance: body weight,feed intake and feed gain ratios of treatment 2 were significantly lower than those of the other groups(P<0.05).There were no significant differences between the treatment groups(P>0.05).At 39 d,compensating growth occurred in treatment 2,3 and 4.The uniformity of treatment 2 and 3 is better than that of treatment 1 and 4.2)Carcassquality:there were no effects on slaughter performance and sternum development of meat ducks(P<0.05).Treatment 2 significantly reduced the shear force of thoracic muscle(P<0.05),while treatment 4 significantly increased the shear force of thoracic muscle(P <0.05).3)Economic benefit accounting: according to the cost calculation per 1000 ducks,the net profit of pattern 1,2,3 and 4 is 3545,3747,3486 and3321 yuan and the net profit of pattern 2 per 1000 ducks is the most.Itcan be concluded that treatment 1,2,3 and 4 can meet the standard of "Diaobai duck".Considering to meat muscle quality and economic benefits,treatment 2 is the most suitable pattern for "Diaobai duck" production.Exp.2 Effects of different feeding restriction on the performance and carcass quality ofmeat duck.This study was to investigate the effects of feeding restriction on productive production performance,carcass quality of meat ducks.900 1d Cherry Valley ducks were fed the same basal diet for 14 d,and were divided into 6 treatment groups according to the principle of no difference in initial weight on 15 d,with 10 replicates for each treatment and15 ducks for each repeat.Treatment 1 was the control group,ad libitum the whole period.Treatment 2,treatment 3 and treatment 4 were fed for 8 hours a day at 14-53 d,21-53 d and28-53 d,respectively,and fasted at the rest of the time.Treatment 5 adopted "5+2" restricted feeding pattern,that is,fasting all day on Tuesdays and Fridays,and ad libitum at other time of a week.Treatment 6 adopted alternate day restricted feeding method,that is,one day fasting,the next day resume ad libitum,such a cycle.The trial lasted 38 days.Samples were collected at 49 d and 53 d to investigate the production performance,carcass quality.After the end of restricted feeding,ad libitum was resumed for one week,and the production performance and fat deposition of 60 days were investigated.The result showed:1)The body weight of treatment 4 and 5 reached 2449.84 g and 2584.93 g respectively on day 49,and that of treatment 6 reached 2493.30 g on day 53.At 15-29 d,the body weight,feed intake and body weight gain oftreatment were significantly lower than those of other treatment groups(P<0.05).The average body weight of treatment 1were significantly higher than those of other treatments(P<0.05).From 36-42 d,43-49 d and50-53 d,the difference of feed gain ratio and body weight gain in each treatment was not significant(P>0.05).During 15-53 d,the feed gain ratio of treatment 1 was lower than that of each restricted feeding group.There was no significant difference in feed intake between treatment groups at 15-53 d.1-49 d,body weight gain,feed intake and feed weight ratio of treatment 4 and 5were no significantly difference(P>0.05).2)Different feeding restricted patterns significantly reduced eviscerated yield with giblet rate,eviscerated yield rate,thoracic muscle rate,sebum rate on day 49(P<0.01)and slaughter rate,wing rate,pectoral muscle rate and abdominal fat rate on day 53(P<0.05).Drips loss was significantly higher than that of the control group at the 49 d and53 day of each restricted feeding.The restricted feeding patterns significantly reduced the tibial indicators and tibial ash content of the sternum(P <0.05),but had no significant effect on the sternum ash content at 49 d and 53 d(P>0.05).At 49 d,the sebum rate and muscle fat content of thetreatment 4 were significantly higher than that of thetreatment 5(P<0.05),and the thoracic muscle rate,sternal depth,keel-length sternum fresh weight and tibial ash content were significantly lower than those of the treatment 5(P<0.05).3)Economic benefit accounting: according to the cost calculation of per 1000 ducks,the net income of treatment 4 and treatment 5at the age of 49day;treatment 6 at 53 day were3301,3100 and 2451 yuan.Net profit of treatment 4 at 49 dayof ageper 1000 ducks is the most.4)Fat deposition: at 53 days,there was no significant difference in liver fat content between treatment 1 and treatment 4,and it was significantly higher than that of treatment2,3,5,6.There was no significant difference in liver fat content between 2,3,5 and 6.There were no significant differences in serum ALT,VLDL-C,NEFA,Glu,insulin,glucagon,leptin content,liver G-6-PDH activity and relative expression of ACC between treatments(P>0.05).Serum AST content: Blood in treatment 1 and 2 were significantly higher than those in other treatments(P<0.05).The content of TP in serum: 3,4,6 was significantly lower than that of treatment 1 and 5(P<0.05).TG content in serum: treatment 5 was significantly higher than treatment 1,3,4(P<0.05).Serum LDL-C levels in treatment 2 and5 were significantly higher than those in treatment 1,3 and 5(P<0.05).Serum HDL content in treatment 5 was higher than that in other treatment groups(P<0.05).TC content in serum:Treatment 6 was significantly higher than other treatments(P<0.05),and treatment 3 was significantly lower than other treatments(P<0.05).Liver LPL activity: treatment 4 was significantly lower than treatment 2,5,6(P<0.05).Liver FAS activity: treatment 2,4,6 was significantly lower than treatment 1 and 5(P<0.05).The relative expression level of FASin liver: Treatment 4 was significantly lower than that of other treatment groups(P<0.05),while treatment 2 and 3 were significantly higher than that of treatment 6(P<0.05).The expressions of MDH and Ch REBP in liver: treatment 4 was significantly lower than treatment 1,2,3;Relative expression of SREBP-1 in liver: treatment 4 was the lowest(P<0.05),while treatment 5 was significantly lower than treatment 6(P<0.05).At the age of 60 d,liver fat content,serum biochemical indicator,insulin and leptin levels in serum and liver activity of FAS,G-6-PDH,relative raw fat related gene expression of each treatment was not significant,but liver LPL and MDHactivity of treatment 1,2,3,4,5 were significantly lowerthan treatment 6(P< 0.05),glucagoncontent of treatment 2 and 5 were significantly higher than that oftreatment 4 and 6(P< 0.05).It can be seen that the feeding pattern of treatment 4 and 5 reached the production standard of "Diao bai duck" at 49 d,and that of treatment 6 reached the production standard of "Diao bai duck" at 53 d.Treatment 5 carcass quality is the best.Conclusion: 1)If the meat duck is 48 days old,it can adopt the pattern 1: free feeding for 6 h/d,31-39 d and 40-48 d according to the weight;Patternl 2:15-28 d for free feeding and 29-53 d for 6 h/d.Pattern: free feeding at 3:15-28 d,and "5+2" restricted feeding at29-53 d.Pattern 2 and Pattern 3 do not need to adjust the feed intake according to the weight in the later period,which can reduce the stress on the duck and save the labor cost.2)If the meat duck is 53 days old,it can adopt pattern 4: 15-28 days free feeding and29-53 days restricted feeding.3)Each restricted feeding patterncan significantly reduce the abdominal fat rate of meat ducks,reduce the content of liver fat,the content of fat synthesis related enzymes in liver and serum,and have no significant effect on the content of insulin,leptin and glucagon.After resuming free feeding,the fat deposition was consistent with that of the control group.