Study on mineral components and untasty flaver in milk of cows fed excessive salt.

本研究旨在澄清岩手县C农场的奶牛经常分泌不好吃的牛奶的原因。咸味怪味奶牛的奶味不佳表现为NaCi浓度高，Na/K浓度比失衡，说明TMR.2中酱油饼和矿质混合物摄入过量盐（160 ~ 170g/头/天）。2 . 4个含C农场和2个参考农场奶牛乳中矿质成分的比较表明，pH与P（P<0.001）、Cl与P（P<0.05）、Na与K（P<0.001）分别呈显著负相关。以奶粉、NaCi、KC1配制了5种不同Na、K浓度（10 ~ 50mla）的牛奶，并进行了8组风味试验。随着Na浓度的升高和K浓度的降低，牛奶中的盐度升高，甜度降低。5头奶牛在16 d内过量盐（200g/头/天），导致3头奶牛饮水量减少，血清钠浓度降低，牛奶和尿液中钠和氯浓度升高，牛奶和尿液中钾浓度降低，牛奶钠钾浓度比升高，血浆ANP浓度降低，3头奶牛分泌出难喝的牛奶。短句来源通过静脉注射抑制特异性钠泵（Na-K- atp酶）的乌阿拜，使4头奶牛血清中Na浓度降低，牛奶和尿液中Na和Cl浓度升高，牛奶和尿液中K浓度降低，牛奶中Na/K浓度比升高，牛奶分泌出难吃的牛奶。综上所述，过量盐饲可能引起钠泵的抑制，导致牛奶中钠钾比例失衡，从而导致牛奶口感变差。

This study aimed to clalify the cause of which cows secreted often untasty milk in the C farm in Iwate Prefecture.1. The untasty milk in cows which had salty and strange tastes showed high NaCi concentration and imbalance of concentration rasio of Na/K, and it became clear that those cows were fed excessive salt(160-170g/head/day) caused by soy sauce cake and mineral mixture in TMR.2. In comparison of mineral components in milk of cows in 4 farmes contained the C farm and in 2 referenes, there were significantly negative correlations between pH and P(P<0.001), Cl and P(P<0.05), and Na and K(P<0.001), respectively.3. A tasty test was done by 8 panelors for 5 milks in different concentration of Na and K(10-50mlA) prepared with milk powder, NaCi and KC1. As Na concentration increased and K concentration decreased, salinity increased and sweetness decreased in milk.4. Five cows were fed excessive salt(200g/head/day) during 16 days and it resulted in decreased water intake, lowered Na concentration in serum, increased Na and Cl concentrations in milk and urine, decreased K concentrations in milk and urine, increased concentration rasio of Na/K in milk, lowered plasma ANP concentration in 3 cows and secretion of the untasty milk in those 3 cows.5. Four cows were intravenously injected of the ouabain which inhibited specificity Na pump(Na-K-ATPase) and it resulted in lowered Na concentration in serum, increased Na and Cl concentrations in milk and urine, decreased K concentrations in milk and urine, increased concentration rasio of Na/K in milk, secretion of the untasty milk.6. It is concluded that the inhibition of Na pump which may be induced in cows fed excessive salt results in imbalance of Na/K in milk and consequently produces the untasty milk.