不同中性洗涤纤维与非纤维性碳水化合物比例日粮对山羊瘤胃和血液氮素利用的影响

Effect of Neutral Detergent Fiber to Non-Fiber Carbohydrate Ratios on Nitrogen Utilization of Rumen and Blood in Goats

试验以4只装有瘤胃瘘管和颈静脉血管留置针的徐淮白山羊(20±2)kg为试验动物,按4×4拉丁方试验设计方案,饲喂由玉米、豆粕、苜蓿干草、羊草等原料组成的中性洗涤纤维(NDF)与非纤维性碳水化合物(NFC)比例(NDF/NFC)分别为2.75(A)、1.71(B)、1.12(C)和0.74(D)组的4种日粮,研究其对山羊瘤胃和血液氮素利用的影响。结果表明:①瘤胃氨态氮浓度随日粮NDF/NFC降低而显著升高,采食1-2 h最高,然后下降。②血浆尿素氮浓度以B组最高为1 2.64 mg/dL,极显著(P<0.01)高于D组,在采食后2 h内升高而后降低,日内波动幅度以D组最大,达到4.36 mg/dL。③瘤胃液部分游离氨基酸如天门冬氨酸和谷氨酸变化显著,其浓度随NDF/NFC降低而逐渐升高。瘤胃总游离氨基酸以D组最高,极显著(P<0.01)高于A组,显著(P<0.05)高于B组。④日粮对血浆游离氨基酸浓度没有显著影响。

Four Xuhuai white goats fitted with permanent ruminal cannulae and jugular fistulae were used to determine the effects of four different diets of neutral detergent fiber to non-fiber carbohydrate ratios （NDF/NFC） on nitrogen utilization of the rumen and blood. The experimental design was 4×4 Latin square, in which four NDF/NFC ratios were： 2.75 （A）, 1.71 （B）, 1.12 （C） and 0.74（D）, respectively. The results showed that （1）Rumen ammonia-N （NH3-N） concentration increased with the decrease of NDF/NFC significantly and increased to the highest value after feeding 1-2 hours, then decreased until the next time＇s feeding. （2）The highest plasma urea-N concentration was observed in B group, which was much higher than that in D group （P 〈 0.01）. There was no significant difference among A, B and C group （P 〉 0.05）. The plasma urea-N concentration was increased after feeding 2 hours, then decreased. The changing range of the plasma urea-N concentration in each group was different, but D group was greatest. （3）The diets had no significant effect on the concentration of free amino acid （FAA） except aspartic acid （Asp） and glutamic acid （Glu） in rumen. Asp and Glu concentration were increased gradually with the decrease of NDF/NFC. The highest rumen total free amino acid （TFAA） was observed in D group, higher than that in A group （P 〈 0.01） and B group （P 〈 0.05）, and was showed no significant difference to C group （P 〉 0.05）. （4）In this experimental condition, the diet composition had no significant influence on plasma FAA concentration.