摘要為了研究在飼料中用植酸酶替代不同水平的磷酸二氫鈣生長
中圖分類號S962.73+2文獻標識碼A文章編號0517-6611(2014)24-08185-03
Effects of Replacement Monocalcium Phosphate of Phytase on Growth of Carassais auratus gibelio
CHEN Jing, XIONG Shenxue et al(Jiangsu Province Aquaculture Technology Extension Station, Nanjing, Jiangsu 210036; Wuxi Aquaculture and Husbandry Technology Extension Station, Wuxi, Jiangsu 214023)
AbstractThe experiment was conducted to evaluate the effects of phytase on growth performances and intestinal emptying velocity of gibel carp (Carassais auratus gibelio). The fish were randomly divided into four groups: a control group, which was fed a basic diet, and four treated groups fed with the basic diet supplemented with 500, 1 000, 1 500 U/kg phytase for eight weeks. The results showed that the replacement Ca(H2PO4)2 of phytase had no significant effect on growth performances of gibel carp (P>0.05). There was no significant effect on growth performances of gibel carp between the treatment group and control group (P>0.05). Meanwhile, the groups supplemented with 500, 1 000, 1 500 U/kg phytase in the diet significantly increased the intestinal emptying velocity of gibel carp (P<0.05) compared with the control. The present study suggests that feed supplementation with phytase has the potential to take replace of the content of calcium dihydrogen phosphate in the diet to some degree. The optimum dietary phytase requirement of gibel carp was estimated to be 1 000 U/kg feed.
Key wordsCarassais auratus gibelio; Phytase; Ca(H2PO4)2; Growth
植酸酶(Phytase)是可將植酸分解為可利用的無機磷酸鹽和肌醇的統(tǒng)稱。水產(chǎn)動物體內(nèi)幾乎無植酸酶,這與單胃動物及禽類大致相同,添加植酸酶能補充內(nèi)源酶不足[1],可能部分解除植酸對內(nèi)源酶的抑制作用,促進內(nèi)源酶分泌,同時因為有植酸的存在可能導(dǎo)致消化酶的失活,如植酸對胃蛋白酶、胰蛋白酶、淀粉酶和脂肪酶的活性有抑制作用,從而降低了蛋白質(zhì)、淀粉和脂肪這些營養(yǎng)物質(zhì)的消化吸收[2],促進水產(chǎn)動物的生長[3]。植酸酶在無胃魚類(如鯉科魚類)飼料中的應(yīng)用已經(jīng)在多次飼喂試驗中證實其使用效果,并通過與酸性植酸酶的對比證實植酸酶在鯉科魚飼料中的應(yīng)用價值[4]。異育銀鯽是我國鯽魚養(yǎng)殖的主要品種,深受消費者的喜愛,近年來還出口到韓國、日本和東南亞等國家和地區(qū)。筆者選用異育銀鯽為研究對象,探討研究在飼料中使用植酸酶替代不同比例的Ca1材料與方法
1.1試驗魚和飼料配方異育銀鯽用5%食鹽水消毒,在水族箱(規(guī)格100 cm×60 cm×80 cm)中馴養(yǎng),馴養(yǎng)期投喂商品飼料,馴養(yǎng)10 d
3討論
等認為在點帶石斑魚的配合飼料中添加植酸酶能更好促進魚體的生長,提高餌料的轉(zhuǎn)化,降低餌料系數(shù)。該試驗結(jié)果表明在試驗組Ⅲ中異育銀鯽的餌料系數(shù)最低且蛋白質(zhì)效率最高,進一步說明植酸酶可以提高磷的利用率,取代部分無機磷。從生產(chǎn)上來看,建議日糧中植酸酶的添加量以1 000 U/kg飼料為宜,其作用相當于8 g/kg的Ca(H2PO4)2。
3.3植酸酶替代磷酸二氫鈣對腸道排空速度的影響腸道食糜排空速度是指腸道中食糜由前向后移動的速度,影響魚類腸道排空速度的因素很多,水溫、飼料形態(tài)、營養(yǎng)物質(zhì)和飼料黏度等都影響魚的排空速度。適宜的腸道排空速度是衡量動物消化道機能的主要指標之一。該試驗中除添加植酸酶外,其他飼養(yǎng)條件一致,在這種情況下飼料原料的粘度是影響食糜消化排空的主要因素,在所加的基礎(chǔ)原料中有菜粕、豆粕、次粉等,其粘性大,影響異育銀鯽腸道排空速度,在日糧中添加植酸酶后,由于植酸酶中含有纖維素酶,有利于降低食糜粘度。該試驗中在其他條件一致的情況下,試驗組比對照組的魚體腸道排空速度明顯加快,而且與對照組差異顯著(P<0.05),說明添加植酸酶可以促進異育銀鯽的食糜排空速度,加快腸道對飼料的消化,這與王愛民等[11]的研究結(jié)果基本一致。從生產(chǎn)上來看,建議日糧中植酸酶的添加量以500~1 000 U/kg飼料為宜,過量添加植酸酶會增加腸道排空速度,影響營養(yǎng)物質(zhì)的消化吸收。
因此,飼料中用植酸酶替代一定量的Ca(H2PO4)2異育銀鯽的生長無顯著影響,添加植酸酶能夠顯著提高腸道食糜排空率。從生產(chǎn)上來看,植酸酶的添加量以1 000 U/kg飼料為宜。
參考文獻
[1] ELSAYED A F M,NMARTINEZ I,MOYANO F J.Assessment of the effect of plant inhibitors on digestive proteases on Nile tilapia using vitro assay[J].Aquaculture,2000,5:403-415.
[2] RICHE M,BROWN P B.Availability of phosphorus form feed stuffs fed to rainbow trout,on corhynchus mykiss[J].Aquaculture,1996,142:269-282.
[3] PAPATRYPHON S. The effects of phytase on apparent digestibility of four practical plant feed stuffs fed to striped bass morone saxatilis[J].Aquaculture Nutrition,2001,7(3):161-167.
[4] 曾虹,姚斌,任澤林.中性植酸酶NPHYA的酶學性質(zhì)及其在鯉魚飼料中的應(yīng)用效果[J].水生生物學報,2002,26(S1):67-74.
[5] 曾虹,姚斌.中性植酸酶在鯉魚飼料中的應(yīng)用效果[J].中國水產(chǎn),2001(5):87.
[6] YOO G Y,WANG X J,CHOI S,et al.Dietary microbial phytase increased the phosphorus digestibility in juvenile Korean rockfish Sebastes schlegeli fed diets containing soybean meal[J].Aquaculture,2005,243:315-322.
[7] 呂林蘭,王愛民,殷玉崗,等.植酸酶對異育銀鯽魚種生長及內(nèi)源酶的影響[J].飼料與糧食工藝,2007(3):36-38.
[8] 郝振榮,高俊杰.植酸酶的應(yīng)用效果研究進展[J].飼料研究,2006(12):12-15.
[9] RODEHUSTSCORD,PFEFFER.Studies on a Planned Provision with Essential Amino Acids and Phosphorus as well as the Utilization of Digestible Energy in Rainbow Trout(Oncorhynchus mykiss Walbaum)[J].Animal Nutrition,1996(2):123-130.
[10] 阮成旭,袁重桂,石祥柱.植酸酶在點帶石斑魚配合飼料中的應(yīng)用[J].福建水產(chǎn),2005(1):13-16.
[11] 王愛民,劉文斌,王恬.外源酶對異育銀鯽內(nèi)源酶活性和腸道食糜排空速度的影響[J]. 江蘇農(nóng)業(yè)學報,2006,22(1):46-50.