不同精粗比饲粮中添加凝结芽孢杆菌对绵羊羔羊生长性能和消化代谢的影响

Effects of Bacillus coagulans Supplementation in Different Concentrate to Forage Ratio Diets on Growth Performance,Digestion and Metabolism of Lambs

本试验旨在研究不同精粗比条件下饲粮添加凝结芽孢杆菌(BC)对绵羊羔羊生长性能和消化代谢的影响。试验采用2×2因子完全随机设计,2个因素分别为精粗比[40∶60(低精料)、70∶30(高精料)]和BC[不添加和添加1.0×1010CFU/kg BC]。选取48只4月龄的杜泊×小尾寒羊F1代公羔,按体重随机分为4个组,分别饲喂低精料饲粮(LD组)、添加BC低精料饲粮(LD+BC组)、高精料饲粮(HD组)、添加BC高精料饲粮(HD+BC组),每组12只。生长性能试验共计70 d,其中预试期10 d,正试期60 d;消化代谢试验共计7 d,其中适应期4 d,取样期3 d。结果显示:1)24只饲喂高精料饲粮羔羊的末重(FBW)和平均日增重(ADG)显著或极显著高于24只饲喂低精料饲粮羔羊(P<0.05或P<0.01),并且料重比(F/G)极显著低于24只饲喂低精料饲粮羔羊(P<0.01);24只饲喂添加BC饲粮羔羊的ADG显著高于24只饲喂不添加BC饲粮羔羊(P<0.05)。2)24只饲喂高精料饲粮羔羊对干物质(DM)、有机物(OM)、中性洗涤纤维(NDF)的表观消化率极显著高于24只饲喂低精料饲粮羔羊(P<0.05),而对酸性洗涤纤维(ADF)的表观消化率则极显著低于24只饲喂低精料饲粮羔羊(P<0.01);24只饲喂添加BC饲粮羔羊对DM、OM、NDF的表观消化率显著高于24只饲喂不添加BC饲粮羔羊(P<0.05)。同时,饲粮精粗比和BC在羔羊对OM和NDF的表观消化率上有显著的交互作用(P<0.05)。HD+BC组的OM和NDF的表观消化率显著高于其他3组(P<0.05)。3)24只饲喂高精料饲粮羔羊的粪能、总能表观消化率、总能代谢率极显著低于24只饲喂低精料饲粮羔羊(P<0.01);24只饲喂添加BC饲粮羔羊的总能表观消化率显著高于24只饲喂不添加BC饲粮羔羊(P<0.05)。饲粮精粗比和BC在粪能和总能表观消化率上有显著的交互作用(P<0.05)。4)24只饲喂高精料饲粮羔羊在氮表观消化率、微生物蛋白(MCP)合成量上显著或极显著高于24只饲喂低精料饲粮羔羊(P<0.05或P<0.01);饲粮精粗比和BC在摄入氮、粪氮、可消化氮、沉积氮、氮沉积率以及血清中尿素氮含量上有显著的交互作用(P<0.05)。综上所述,饲粮中添加BC较不添加BC可提高绵羊羔羊对饲粮中OM、DM、NDF的消化吸收,有效提高总能表观消化率,进而促进羔羊生长。相较饲喂精粗比为60∶40的饲粮,饲喂精粗比为70∶30的饲粮可提高绵羊羔羊对饲粮中OM、DM、NDF的消化吸收,有效提高总能表观消化率、氮表观消化率和MCP合成量,提高羔羊的生长性能。因此,BC可以作为一种新型的益生菌制剂应用于羔羊生产中,且在精粗比为70∶30的高精料饲粮中添加效果更优。

The aim of this experiment was to investigate the effects of Bacillus coagulans(BC)supplementation on growth performance,digestion and metabolism of sheep and lambs under different dietary concentrate to forage ratios.A 2×2 factorial completely randomized design was used in the experiment,with dietary concentrate to concentrate ratio[40∶60(low concentrate)and 70∶30(high concentrate)]and BC[no-added and added(1.0×1010 CFU/kg)]as two factors.Forty-eight F1 male lambs of Dolper×small-tail Han sheep aged 4 months were randomly divided into 4 groups according to body weight,they were fed low-concentrate diet(LD group),low-concentrate plus BC diet(LD+BC group),high-concentrate diet(HD group)and high-concentrate plus BC diet(HD+BC group),each group had 12 lambs.The growth performance test lasted for 70 days with the 10 days of pre-test period and 60 days of trial period,and the digestion and metabolism test lasted for 7 days with 4 days of adaptation period and 3 days of sampling period.The results showed as follows:1)final body weight(FBW)and average daily gain(ADG)of 24 lambs fed high-concentrate diet were significantly or extremely significantly higher than those of 24 lambs fed low-concentrate diet(P<0.05 or P<0.01),and feed/gain(F/G)of 24 lambs fed high-concentrate diet was significantly lower than that of 24 lambs fed low-concentrate diet(P<0.01).The ADG of 24 lambs fed BC added diet was extremely significantly higher than that of 24 lambs fed no BC added diet(P<0.05).2)The apparent digestibility of dry matter(DM),organic matter(OM)and neutral detergent fiber(NDF)of 24 lambs fed high-concentrate diet was significantly higher than that of 24 lambs fed low-concentrate diet(P<0.05),while the apparent digestibility of acid detergent fiber(ADF)of 24 lambs fed high-concentrate diet was extremely significantly lower than that of 24 lambs fed low-concentrate diet(P<0.01).The apparent digestibility of DM,OM and NDF of 24 lambs fed BC added diet was significantly higher than that of 24 lambs fed no BC added diet(P<0.05).At the same time,dietary concentrate to forage ratio and BC had a significant interaction on the apparent digestibility of OM and NDF(P<0.05).The apparent digestibility of OM and NDF in HD+BC group was significantly higher than that in other three groups(P<0.05).3)The fecal nitrogen,gross energy apparent digestibility and gross energy metabolizability of 24 lambs fed high-concentrate diet were significantly lower than those of 24 lambs fed low-concentrate diet(P<0.05).The gross energy apparent digestibility of 24 lambs fed BC added diet was significantly higher than that of 24 lambs fed no BC added diet(P<0.05).Dietary concentrate to forage ratio and BC had a significant interaction on the fecal nitrogen and gross energy apparent digestibility(P<0.05).4)The nitrogen apparent digestibility and microbial protein(MCP)synthesis amount of 24 lambs fed high-concentrate diet were significantly or extremely significantly higher than those of 24 lambs fed low-concentrate diet(P<0.05 or P<0.01).Dietary concentrate to forage ratio and BC had a significant interaction on nitrogen intake,fecal nitrogen,digestible nitrogen,retained nitrogen,nitrogen deposition rate and serum urea nitrogen content(P<0.05).In summary,dietary supplementation of BC can improve the digestion and absorption of OM,DM and NDF,effectively improve the gross energy apparent digestibility,and thus promote the growth of lambs.Relative to feeding diet with the concentrate to forage ratio of 60∶40,feeding diet with the concentrate to forage ratio of 70∶30 can improve the digestion and absorption of OM,DM and NDF,effectively improve the gross energy apparent digestibility,nitrogen apparent digestibility and MCP synthesis amount,and improve the growth performance of lambs.Therefore,BC can be used as a new probiotic preparation in lamb production,and the effect of adding BC to 70∶30 high-concentrate diet is better.