| In this experiment,pure lines, parents, commercial breeds of Gushi chicks, Ross roosters and Avin broiler chicks are raised to 4 weeks old under the same condition,then 300 of each group except avin were selected and divided 2 groups equally,one group was captive caged ,the other group was free-range reared from 5 weeks to 18 weeks . each group was distributed into 3 repetition,and each repetition includes 50 chicks.bodily form of 3 generation of gushi chicks were measured every two weeks, slaugher qualities were measured in the end of 18 weeks.The activity of pepsin ,trypsin, total proteinase,a-amylase ,lipase and cellulase in the stomachal , small intestinal and caecum contents ,the length of duodenum jejunum-ileum,caeca and rectum were measured respectly on the end of 4 weeks and 18 weeks.furthermore we observe gland paunch tissue morphology structure of small instinal ,caeca and rectum of gushi pure lines and avin broiler chicks utilizing optical and electronic microscope .On the basis of gushi weight and partly bodily form parameter ,we analyzed growth and development of 3 generations of gushi in the periods of 4-18weeks under the free range rearing condition , The results showed that 3 generations of gushi have the same characteristic : weight growth increased slowly in the periods of 4-18 weeks,in the end of 18 weeks ,skeleton yet have higher growing speed.comparing to growth state of chicks under the other breed conditions,the peak of weight growth and skeleton development were postponed or deleyed .the article have relative analysis to parameters and give regress curve of weight to shrank lengh and body weight, shrank lengh, body lengh, chest breath lengh, pelvis width to day-age.The slaugher experiment showed:raising method and breed have different effect on different slaugher qualities . carcass yield rate, brawn bressing percentage of FRR are higher than that of CCR, half- brawn bressing percentage of FRR is lower than that of CCR,the difference was not signifficant (p>0.05). hindquater muscle percentage of , in the FRR is higher than that in the CCR ,but the difference was not significant (p>0.05). parents and roosters in the FRR are higher than that in the CCR significantly (p<0.05), commercial breeds in the FRR is lower than that in the CRR,the difference was not significant (p>0.05).breast muscle percentage of parents, pure lines and rooster in FRR are all signifficantly than that in CRR . commercial breeds in the FRR is higher than that in the CRR, the difference was not signifficant (p>0.05). pure lines, Ross roosters in the FRR are higher than that in the CRR .the difference was not signifficant (p>0.05). commercial breeds in the FRR is higher than that in the CRR signifficantly (p<0.05). parents in the FRR is lower than that in the CRR, the difference was not signifficant (p>0.05). live weight of frr is lower than that of CRR significantly (p<0.05).breed have little effect on carcass yield rate, brawn bressing percentage, half- brawn bressing percentage.different breeds have littler difference in the FRR or CRR (p>0.05).while breed have significant effect on live weight, hindquater muscle percentage, breast muscle percentage, percentage of abdom inal fat.the diffrence is significant among different group in the FRRor CRR.Relative growth speed result of digestive tract show: Relative growth speed of length of duodenum ,jejunum-ileum,caeca and rectum have the same speed of Relative growth speed of weight.frr or err have little effect on it.The results showed that there were no significent difference among each group in the 4 weeks old (p>0.05). in the 18 weeks old ,the activity of 3 breeds Gushi chicks in the (FRR) were far more higher than these of their in the captive caged rearing (CCR) (p<0.05). there were no significent differentce for pepsin,trypsin and total proteinase between 2 conditions among each group (p>0.05), while the a-amylase and lipase activity in free range rearing (FRR) were lower significently than these in the captive caged rearing (CCR) (p<0.05). the above digest... |
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