论文部分内容阅读
This study was condcted to evaluate the effects of replacing partialformula feed with forage on the performance, carcass characteristics, meatqualities, activihes of digestive enzympes, serum metabolites and hormonesin growing-finishing pigs. Forty thrre-way(Duroc× Landerae× JiaxingBlack) growing pigs were randomly assigned to 4 dietary treatment. Thepigs in control (C) were fed on concetrate. In the other three treatments(T1,T2,T3), concentrate was substituted with fresh or ensiled ryegrass atl0～20% （DM basis). After feeding trial, six pigs in each treatmen wereslaughtered to detemine carcass characteristics. At the same time, theblood was sampled to determine the content of tryglycerides, cholesterol,urea nitrogen glucose, etc. Samples of contents in small and largeintestines were taken to determine the activities of digestive enzymes.Loin sample was also taken to determine meat qualityThe partial substitution of concentrate with forage did not influencethe growth rate of pigs. No significant difference was found in averagedaily gain, but the feed conversion ratios in T1, T2 and T3 were reducedby 10.9, l0.3and 11.9%, respectively.The carcass compositions were affected by forage inclusion. Thedressing percentages of animals were 75.1, 70.3, 67.2 and 67.7% in groupsC, Tl, T2 and T3, respectively The dressing Percentages of pigs was6.4(P<0.01), 10.5(P<0.01) and 9.7%(P<0.01) lower in T1, T2, T3 than that in group C．Forage inclusion also reduced the percentages of dissected fat and skin, and increased percentage of dissected lean.Pigs receiving forage showed slight increase in weight of stomach, small and large intestines． Increasing levels of oye signfiCantiy reduCed he concenraons of cholesterol n mod nd backfat．A sighfiCan ncrease n he conten of inoslnlc acid n loin was observd as op level illcreaseQ n he iet． COwl to he pigs m C，Olll6llt OfmSmCoid Of IOO INSSI3．7， 42．8（＜001）nd 52．侧＜001）igher n grorpS TI，h nd T3， respewvely he PH value nCreased by 5．8（＞00D，7．3o／o（＞00） nd 7侧功吩hd饲刚hT乙n恤D．H仰删巩pH咖h 1h6colon ws蜘 as5pe level mcreas＊m61a．）e …啊 MO Of吨 Odla一M t讪S OfogO咖 enZyms n duodenUm．he mvity of Prtheighc enZym ws 12．30＞啊12．3o＞啊24．1％o＞2MI。腑hM－。＊ pigs n TI，h nd T3 than tba n C．COIDpatd to C，he amylase aCivity of＊the pigs also deceaseQ n TI，h nd T3．he aciiy ofendglucanase ws si卯fi咖y t n colon of pigs fd ope．iiis could be due to igh onten of i卿 ib n fo呷e，oh＊can Promdethe aCfrtvities of nucrobes m colon． 刀Orag sreQllceQthe！删IS Of呐1wmdaandcho k一IO S——． he leve ofboyCerides deceased ZI．7 （＜001），28刀％（＜001）and 20．5％ （＜001）n TI，h nd T3，re…vey Ihing leves offoop resuitedsulted m a sign6wn血以壮on（P＜0of）n cone6lllts［lon ofchoe幻e正ok However it ＆a no anect i leve or glll－－－－－－－cwc ransalnlllase （GP D，gll．－－－－．－－－－－－c－oxaloac＊cbellsallllnase （G几db山记咖耶h呛驴 （AL），S————io ge4 total Pote S ndndJ——％m——． he levels ofserum ree teualodomethan we 30．6，34．3 nd 39．8％ igher （＞00D n TI，h nd T3 than tha n C．he anhals n grorp TI 68 had he ighot COlCentaon of sennn growth honnone＞0 OD，ith Inde diffbrellce amn he other e．he serum nslin leve ws 15．6（＞00J），gi．9（＜00D nd 38．5％（＞00D igher n TI，h nd