田雯　王洪榮

摘 要：試驗研究不同日糧模式對奶牛乳腺對氨基酸的攝取效率和乳腺動靜脈激素變化規(guī)律的影響。選用經(jīng)產(chǎn)，體況良好，體重、產(chǎn)奶量、泌乳天數(shù)相近的荷斯坦奶牛10頭，隨機分為兩組，分別飼喂混合粗飼料日糧（IMF）和低精料秸稈日糧（CS2）。飼喂第21d對尾動脈和乳靜脈采集血樣，測定血液中游離氨基酸和激素（COR、IGF-Ⅰ、HGH、LEP、INS和PRL）濃度。結果表明：（1）IMF組動脈血中COR、HGH、LEP、INS和PRL濃度分別比CS2組的高；IMF組靜脈血中COR、IGF-Ⅰ、HGH、LEP和INS濃度分別比CS2組的高，除HGH差異顯著外，其余均不顯著；兩組中乳靜脈中IGF-Ⅰ和INS分別比尾動脈中的高。此外，HGH、INS和PRL在飼喂后2-3h達到一個高峰值，隨后進行波動變化，而COR、IGF-Ⅰ和LEP比以上三種激素早達到高峰值，高峰值一般出現(xiàn)在飼喂后1-2h。（2）IMF組奶牛乳腺對Glu和Arg的攝取率顯著高于CS2組，而對Cys的攝取率呈低于CS2組的趨勢且為負值；對于Gly的攝取率兩組均較低，且IMF組為負值；IMF組奶牛乳腺對和支鏈氨基酸（Val、Ile和Leu）的攝取率均高于CS2組，但差異不顯著。以上研究結果表明，功能性氨基酸（Arg、Ser、Val、Ile和Leu等）和激素（COR、IGF-1、HGH、LEP、INS和PRL）在奶牛乳腺合成乳蛋白過程中起著重要作用。

關鍵詞：功能性氨基酸 激素 奶牛 乳腺 乳蛋白

Abstract：This experiment was conducted to study the effects of different diets on extraction of amino acids and change lows of hormones of arterial and venous blood in the Mammary Gland of Dairy Cows. According to the principle of close weight， milk yield and lactation days， 10 holstein cows which were multiparity and had good body conditions were randomly assigned to 2 groups with 5 replicates. Two groups diets were respectively mixed forage （IMF） and low-concentrate and corn stover （CS2）.Blood sample were collected at 21d for determination of the concentrations of free amino acids and hormones （COR， IGF - Ⅰ， HGH， LEP and INS and PRL）in milk venous and caudal arterial blood. The results showed that：（1） Concentrations of COR， HGH， LEP and INS and PRL in the arterial blood of group IMF were higher than group CS2 respectively.Compared with the concentrations of COR， IGF -Ⅰ， HGH， LEP and INS in the venous blood of group CS2， group IMF were all higher，the HGH was significant difference，and the rest were not.The concentrations of IGF -Ⅰ and INS in the venous blood was higher than in the arterial blood of two groups respectively. In addition，the concentrations of HGH，INS and PRL reached a peak after feeding 2 to 3 h， subsequently changed by rule of wave. However， the concentrations of COR， IGF -Ⅰ and LEP reached the peak earlier about one hour than those hormones.（2）The extractions of Glu and Arg in mammary gland of dairy cow of group IMF were significantly higher than group CS2， while the extraction of Cys was negative and trended lower than group CS2.For the extraction of Gly， two groups were low， and group IMF was negative. The extractions of branched chain amino acids （Val， Ile and Leu） in mammary gland of dairy cow of group IMF were all higher than group CS2， but had no significant difference .Above results indicated that the functional amino acids （Arg， Ser， Val， Ile and Leu， etc.） and hormones （COR， IGF-1， HGH， LEP and INS and PRL） played an important role in the process of the synthesis of milk protein in mammary gland of dairy cow.

Key Words：Functional amino acids；Hormones；Dairy cow；Mammary gland；Milk protein

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