摘要
本试验通过十二指肠大豆小肽梯度灌注,旨在研究不同水平的小肽对泌乳中期奶山羊乳成分、血液生化指标、激素水平及小肠肽转运载体(PepT1)表达活性的影响。试验选用12只平均体重为(38±2)kg、带有十二指肠瘘管的泌乳奶山羊,分成4组,分别灌注小肽0、60、120、180 g/d,试验日粮相同,连续灌注14 d。结果表明:通过小肽的灌注,(1)增加了乳蛋白产量(P<0.05),乳蛋白含量也有所增加,但仅在120 g/d试验组差异显著(P<0.05)。乳脂产量与乳脂含量随着灌注量的升高呈显著下降趋势(P<0.05)。乳中尿素氮含量随着灌注量的升高而增加(P<0.05);(2)血清中总蛋白和球蛋白含量均高于对照组,但仅在120 g/d试验组差异显著(P<0.05)。白蛋白含量反而较对照组相比有所降低(P<0.05),尿素氮的含量显著升高(P<0.05)。血清中生长激素浓度随着大豆小肽灌注量的增加而升高(P<0.05),胰岛素浓度也表现出增加趋势,但只有在180 g/d试验组差异显著(P<0.05);(3)PepT1表达在十二指肠、空肠、回肠随着灌注量的增加而升高。小肽灌注组PepT1在十二指肠表达丰度分别是对照组的1.6、2.6、5.4倍;回肠表达丰度是对照组的1.1、1.4、3.3倍;在空肠中表达是对照组的1.1、1.8、2.4倍。随着灌注量的增加,PepT1在十二指肠表达的增加尤为显著,在180 g/d试验组,PepT1十二指肠表达量分别为空肠、回肠的1.5、1.6倍。本研究揭示,小肽的灌注可以提高PepT1表达活性,增加小肽吸收,促进乳蛋白合成,并在120 g/d试验组表现尤为显著。
To study the effects of duodenal infusion of soybean small peptides on milk composition, blood biochemical indices and mRNA expression of PepT1 in small intestine, twelve Chinese saanen lactating goats with an average body weight of （38±2） kg with duodenal fistula were divided into four groups and were infused 0, 60, 120 and 180 g/d soybean small peptides, respectively. The infusion period lasted for 14 d. The results showed： 1） yield （P〈0.05） and percentage of milk protein were increased and the effect was significant in 120 g/d treatment （P〈0.05）. Milk fat yield and content were decreased with increasing infusion of soybean （P〉0.05）. Milk urea nitrogen was increased with the increase amounts of soybean small peptides infusion （P〈0.05）; 2） in serum, the contents of total protein and globulin were numerically higher in soybean small peptides treatments than those in control group and the effect was significant in 120 g/d treatment （P〈0.05）. The albumin content in serum was lower compared with the control group （P〈0.05）. The contents of urea nitrogen and growth hormone were increased with the increment of amounts of soybean small peptides infused （P〈0.05）, and that of insulin was numerically increased （P〉0.05）, but the effect was significant only in 180 g/d treatment （P〈0.05） ; 3） mRNA expression of PepT1 in duodenum, jejunum and ileum was increased with increasing amount of soybean small peptides infused. In soybean small peptides treatments, mRNA expression of PepT1 in duodenum was 1.6, 2.6, 5.4 folds, that in jejunum was 1.1, 1.4, 3.3 folds and in ileum was 1.1, 1.8, 2.4 folds higher than that in control group, respectively. With the increasing amount of soybean small peptides infused, PepT1 expression in duodenum was 1.5 and 1.6 folds higher than that of jejunum and ileum in 180 g/d treatment. The current results suggested that the mRNA of PepT1 in small intestine was increased by small peptides infusion, and the absorption of small peptides an
出处
《动物营养学报》
CAS
CSCD
北大核心
2009年第3期319-325,共7页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家自然科学基金资助项目(30671521)
关键词
大豆小肽
PepT1
乳成分
血清生化指标
奶山羊
Soybean small peptides
PepT1
Milk composition
Blood biochemical indices
Lactating goats
