饲粮非纤维性碳水化合物/中性洗涤纤维对肉犊牛生长性能和营养物质消化代谢的影响

摘要

本试验旨在研究饲粮非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)对断奶肉犊牛生长性能、血清生化指标和营养物质消化代谢的影响.选取2~3月龄健康、平均体重为(94.38±0.25) kg的断奶肉犊牛60头,随机分为4组,每组15头.分别饲喂粗蛋白质水平相近,NFC/NDF分别为1.35(A组)、1.23(B组)、0.94(C组)和0.80(D组)的4种全混合日粮.试验期105 d,其中预试期15 d,正试期90 d.每日测定采食量,每隔15 d测量犊牛的体重;于15、30、45、60、75和90 d颈静脉采血测定血清葡萄糖(GLU)、生长激素(GH)、胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、瘦素(LEP)、胰岛素(INS)、胰高血糖素(PG)和甘油三酯(TG)的浓度;分别在30和90 d时以全收粪尿法进行消化代谢试验.结果表明:1)高NFC/NDF饲粮提高了犊牛的平均日增重,A组显著高于其他3组(P<0.05);2)A组血清LEP浓度显著高于C组和D组(P<0.05),D组血清IGF-Ⅰ浓度显著高于其他各组(P<0.05);3)90 d时,干物质、中性洗涤纤维和酸性洗涤纤维的表观消化率及总能消化率、总能代谢率和消化能代谢率随饲粮NFC/NDF的降低而降低,A组均显著高于D组(P<0.05),D组甲烷能显著高于其他组(P<0.05),A组尿能、尿氮和消化氮显著高于B组和C组(P<0.05).综上所述,NFC/NDF为1.35的饲粮可以满足3~6月龄肉犊牛对营养物质的需求,采食该饲粮不但可以使肉犊牛保持较高的平均日增重(1.14 kg/d),而且此饲粮易消化利用,采食后相关血清生化指标均在正常范围内,并未影响犊牛健康.%This study aimed to investigate the influences of dietary with non-fiber carbohydrate (NFC)/neutral detergent fiber (NDF) on growth performance, serum biochemical indexes and nutrient digestion and metabolism of weaned meat calves.Sixty 2-to 3-month-old healthy weaned meat male calves were randomly divided into four groups with fifteen calves each, and were fed four types of total mixed ratio with the same crude protein level and different NFC/NDF.The experiment lasted for 105 d with 15 d of adaptation period and 90 d of formal period.Feed intake was recorded everyday, and body weight of calves was measured every 15 d;blood was sampled at 15, 30, 45, 60, 75 and 90 d to determine the concentrations of serum glucose (GLU), growth hormone (GH), insulin-like growth factor-Ⅰ (IGF-Ⅰ), leptin (LEP), insulin (INS), glucagon (PG) and triglyceride (TG);digestion and metabolism experiments were carried out at 30 and 90 d using total feces and urine collection method.The results showed as follows: 1) the diet with high NFC/NDF increased average daily gain (ADG) of calves, and group A was significantly higher than the other 3 groups (P<0.05);2) serum concentration of LEP in group A was significantly higher than that in groups C and D (P<0.05), and serum concentration of IGF-Ⅰ in group D was significantly higher than that in the other groups (P<0.05);3) at 90 d, with the decrease of dietary NFC/NDF, the apparent digestibility of dry matter, acid detergent fiber and neutral detergent fiber, as well as gross energy (GE) digestibility, GE metabolic rate and digestive energy metabolic rate were decreased, and group A was significantly higher than group D (P<0.05);methane energy in group D was significantly higher than that in the other groups (P<0.05);urine energy, urine nitrogen and digestible nitrogen in group A were significantly higher than those in groups B and C (P<0.05).To sum up, dietary NFC/NDF of 1.35 can meet the nutrient needs of meat calves at 3 to 6 months of age, the diet can not only make calves to maintain a high ADG of 1.14 kg/d but also be easy to digest, and serum biochemical indexes are in normal range after feeding without influence on the health of calves.