[Variations in the pattern of ruminal volatile free fatty acids, acetoacetate and glucose in the blood plasma of lactating cows after a period of fasting and renewed feeding].
3 lactating cows were fasted for 4 days and then again received food. The trial was performed to investigate the effect of fasting on the concentration and molar proportion of volatile fatty acids in the rumen, on the concentration of free fatty acids and glucose in blood plasma and on the acetoacetate concentration in the blood. Fasting produced a considerable decrease in the total concentration of volatile fatty acids. Processes of ruminal fermentation were characterized, during the fasting period, by a continuous increase in the molar proportions of acetic acid, isobutyric acid and isovaleric acid whereas a significant decline observed to occur in the molar proportions of propionic acid and butyric acid. The reciprocal behaviour of acetate and propionate under conditions of fasting lead to a linear increase in the C2 to C3 ratio from 4.4 : 1 to 9,6 : 1. With renewed food supply all fermentation data returned to normal levels. The concentrations of blood glucose declined after 24 hrs of fasting, remained at the same level for the following 2 days and rose again to normal values on the 4th day of fasting. The concentration of acetoacetate decreased significantly on the first day of fasting to values that were 4 times as high as the initial value. The concentration of free fatty acids in blood plasma increased tremendously to a value 40 times as high as that observed at the beginning of the fasting period. It proved to be a good indicator for the energy requirements of the organism.
D000090:Acetoacetates / Q000097:blood*; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D002417:Cattle; D005215:Fasting; D005232:Fatty Acids, Volatile / Q000097:blood*; D005260:Female; D007774:Lactation; D011247:Pregnancy; D012417:Rumen / Q000032:analysis*; D013997:Time Factors
D000090:Acetoacetates; D001786:Blood Glucose; D005232:Fatty Acids, Volatile
Veränderungen der flüchtigen Fettsäuren im Pansensaft sowie der freien Fettsäuren, des Azetoazetats und der Glukose im Blutplasma laktierender Kühe nach Hunger und erneuter Nahrungszufuhr