日粮中添加不同水平紫苏籽对湖羊生长性能、 瘤胃发酵及养分表观消化率的影响

本试验旨在研究日粮中添加不同水平紫苏籽(Perilla frutescens seed,PFS)对湖羊生长性能、血清生化指标、养分表观消化率及瘤胃发酵的影响。选取2月龄、平均初始体重为(23.02±1.36)kg的湖羊公羔60只,依据日粮中PFS含量随机分成为:对照组(Control)、5%紫苏籽组(5%PFS)、10%紫苏籽组(10%PFS)和15%紫苏籽组(15%PFS)。预试期14d,正试期70d。饲喂试验结束前21d,从各组随机挑选4只羊进行7d的消化代谢试验。试验结束后称重,计算平均日增重(ADG),并采集瘤胃液和血液分别用气相色谱法、比色法、全自动生化分析仪和酶联免疫分析法测定瘤胃液挥发性脂肪酸(VFA)、氨态氮(NH_3-N)、血清中总蛋白(TP)、尿素氮(UN)、葡萄糖(Glu)和血清中生长激素(GH)、胰岛素样生长因子-1(IGF-1)等。结果表明,日粮中PFS水平对湖羊生长性能(干物质采食量、平均日增重和料重比)、血清生化指标(TP、UN、Glu、GH和IGF-1)、瘤胃pH和瘤胃液乙酸、丙酸及总挥发性脂肪酸(TVFA)等含量的影响不显著(P0.05),但随着PFS添加水平的升高,乙酸、丁酸和TVFA的含量呈降低趋势,丙酸呈上升趋势;与对照组相比,15%PFS组中NH_3-N和乙酸/丙酸极显著降低(P0.01);添加PFS不影响日粮中粗脂肪(EE)和酸性洗涤纤维(ADF)的表观消化率(P0.05),但干物质(DM)、有机物(OM)和中性洗涤纤维(NDF)的表观消化率随着PFS添加水平升高而下降,且15%PFS组的DM和OM的表观消化率均极显著低于对照组(P0.01);与对照组相比,10%PFS组的粗蛋白(CP)表观消化率极显著提高(P0.01),而15%PFS组的极显著降低(P0.01)。综上所述,湖羊日粮中添加PFS水平为10%时,饲喂效果较好。

Effect of dietary Perilla frutescens seed intake on rumen fermentation characteris-tics,apparent nutrient digestibility,and growth performance of Hu sheep

The objective of this study was to evaluate the effect of the amount of Perillafrutescensseed (PFS) in the diet on the serum biochemical parameters,rumen fermentation characteristics,apparent nutrient digesti-bility,and growth performance of Hu sheep.Sixty male Hu lambs aged 2 months and weighing on average (23.02±1.36)kg were randomly divided into four groups and fed on diets containing varying proportions of PFS:0% (control),5% (5%PFS),10% (10%PFS)and 15% (15%PFS)for 70 days.At 21 days before the end of the feeding experiment,four lambs were randomly selected from each experimental group for a 7-day di-gestion and metabolism experiment.At the end of the feeding period,lambs were weighed to calculate average daily gain (ADG).Blood and rumen fluid samples were collected for analysis.Volatile fatty acids (VFA),am-monia nitrogen (NH3-N),total protein (TP),urea nitrogen (UN),glucose (Glu),growth hormone (GH), and insulin-like growth factors 1 (IGF-1 )were quantified in the samples using gas chromatography,colorimet-ric,automatic biochemical analyzer,and ELISA methods.The results showed that the amount of PFS did not significantly affect growth performance (dry matter intake,ADG,and feed/gain ratio),blood biochemical in-dices (TP,UN,Glu,GH and IGF-1),rumen pH,or the concentrations of acetic acid,propionic acid,and to-tal VFA (P>0.05).With increasing dietary PFS,the concentrations of acetic acid,butyric acid,and total VFA tended to decrease,whereas the concentration of propionic acid tended to increase.Compared with the control group,the 15%PFS group showed significantly decreased NH3-N content and acetate:propionate ratio (P<0.01 )in the rumen fluid.The amount of PFS did not affect the apparent digestibility of ether extract (EE)and neutral detergent fiber (NDF)(P>0.05).However,the apparent digestibility of dry matter (DM), organic matter (OM),and NDF decreased with increasing amounts of PFS in the diet.The apparent digestibili-ty of DM and OM was lower in the 15%PFS group than in the other groups (P<0.05).Compared with the control group,the 10%PFS group showed significantly increased apparent digestibility of crude protein (CP) (P<0.01),while the 15%PFS group showed a significant decrease in this parameter (P<0.01).In conclu-sion,10% PFS in the diet is the appropriate level of supplementation for Hu sheep.