断奶仔猪血清氨基酸含量和生化参数对不同蛋白质水平饲粮的动态响应

本文旨在研究断奶仔猪血清氨基酸含量和生化参数对不同蛋白质水平饲粮的动态响应。选取18头35日龄平均体重为(10.0±1.0)kg三元(杜×长×大)杂交断奶阉公猪,随机分为3组(每组6个重复,每个重复1头猪),并分别饲喂蛋白质水平为14%(LP)、17%(M P)和20%(HP)的饲粮。每头试验猪安装颈动脉血管插管,术后恢复5 d,于第6~8天正式试验。每天采食前,采食后30、60、120、180和300 min连续采集颈动脉血液10 m L,分别检测血清游离氨基酸含量和相关生化指标。结果表明:不同蛋白质水平饲粮对仔猪采食前后各时间点血清中游离赖氨酸(Lys)、蛋氨酸(Met)、苏氨酸(Thr)、色氨酸(Trp)、天冬氨酸(Asp)、丝氨酸(Ser)、甘氨酸(Gly)和谷氨酸(Glu)含量影响均不显著(P0.05)。但血清中Lys、Met、Thr、Trp含量随饲粮蛋白质水平的降低而升高。HP组仔猪采食前后各时间点血清游离氨基酸缬氨酸(Val)、异亮氨酸(Ile)、精氨酸(Arg)]和尿素含量显著高于MP和LP组(P0.05)。采食后120~300 min HP组血清Leu含量显著高于LP组(P0.05)。采食后各时间点LP组血清总蛋白(TP)、白蛋白(ALB)含量及碱性磷酸酶(ALP)活性显著高于HP和MP组(P0.05)。各组仔猪采食后血清游离氨基酸含量和相关生化指标随时间变化无显著差异(P0.05)。综上所述,断奶仔猪饲粮在平衡4种氨基酸(Lys、Met、Thr、Trp)的基础上,常规饲粮蛋白质水平降低3个百分点,血清游离Val、Ile、Arg含量显著降低,但对血清中其他氨基酸和相关生化指标无显著影响;而蛋白质水平降低6个百分点,血清游离Leu和尿素含量显著降低,TP、ALB含量和ALP活性显著升高,但对血清中其他氨基酸和相关生化指标的影响不显著。

Dynamic Changes of Serum Amino Acid Content and Biochemical Parameters of Weaned Piglets in Response to Diet with Different Protein Levels

The study was conducted to investigate the dynamic changes of serum amino acid content and bio?chemical parameters of weaned piglets in response to diet with different protein levels. Eighteen 35?day?old weaned barrows (Duroc×Large White×Landrace) with an average body weight of (10.0±1.0) kg were ran?domly divided into three groups ( 6 replicates in each group and 1 pig in each replicate) , and fed diets with 20% ( HP group) , 17% ( MP group) and 14% ( LP group) crude protein, respectively. Each piglet was in?stalled a carotid artery intubation by surgery, and after 5 days of postoperative recovery, days from 6 to 8 were regarded as trial period. Before fed intake and after feeding for 30, 60, 120, 180 and 300 min every day, all piglets were collected carotid artery blood, and serum amino acid contents and biochemical parameters were de?termined. The results showed that serum contents of free amino acids including Lys, Met, Thr, Trp, Asp, Ser, Gly and Glu had no significant difference among three groups at different time points when piglets were fed different protein level diets ( P>0.05) . There was a negative correlation between the contents of Lys, Met, Thr and Trp with dietary protein level. Serum contents of Val, Ile, Arg and urea in HP group were significant?ly higher than those in MP and LP groups at different time points ( P<0.05) . Serum Leu content in HP group was significantly greater than that in LP group after feeding for 120 to 300 min ( P<0.05) . Serum contents of total protein ( TP) and albumin ( ALB) as well as alkaline phosphatase ( ALP) activity in LP group were sig?nificantly higher than those in HP and MP groups at different time point after feeding ( P<0.05) . There was no significant difference in the serum amino acid content and biochemical parameters with time flow after piglets were fed ( P>0.05) . The results showed that based on balancing the contents of Lys, Met, Thr and Trp, a re?duction of dietary protein level by a three?percentage value remarkably decreases the contents of serum Val, Ile and Arg, but has no effects on other amino acids and related parameters; while a reduction of dietary protein level by a six?percentage value significantly decreases serum contents of Leu and urea and increases the serum contents of TP, ALB and ALP, but dose not affect other amino acids and related parameters.