1998 Fiscal Year Final Research Report Summary
Study on mineral components and untasty flaver in milk of cows fed excessive salt.
Project/Area Number |
09660296
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Applied animal science
|
Research Institution | Iwate University |
Principal Investigator |
SHIGA Akio Fac.of Agriculture, Professor, 農学部, 教授 (20003783)
|
Co-Investigator(Kenkyū-buntansha) |
OKADA Keiji Fac.of Agriculture, Research Associate, 農学部, 助手 (60233326)
|
Project Period (FY) |
1997 – 1998
|
Keywords | Cow / Salt / Salty / Untasty milk / Na / K rasio / Na pump / Plasma ANP concentration / Ouabain |
Research Abstract |
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.
|