Electromagnetic Blood Flow Recording and Balance of Nutrients in the Udder of Lactating Cows1

Abstract

An electromagnetic method was adapted to quantitatively measure blood flow through an external pudic artery of the udder in lactating cows during several months. Blood flow through the ipsilateral external pudic vein was blocked while blood was taken from a subcutaneous abdominal vein. Blood flow to milk yield ratio amounted to a mean value of 507:1 in three cows. Peak milk yield occurred before the time of our experiments. There was a high correlation (r = .73) between mammary arterial blood flow and milk yield. Arterio-venous differences (AV) across the udder demonstrated that essential amino acids (EAA) were taken up by the mammary gland in sufficient amounts to account for the EAA secreted as milk protein. Uptake of valine, isoleucine, lysine and particularly that of arginine was in excess of that for milk protein synthesis. There was a highly significant correlation (P<.01) between AV differences of several amino acids and their corresponding arterial concentrations. Uptake of glucose was This work was supported by grants from the lnstirut pour l'Encouragement de la Recherche Scientifique dans l'Industrie et l'Agriculture. The authors gratefully acknowledge Professor Dr. W. Welvaert of the Department of Phytopathology and Phytovirology of the University of Ghent, in whose laboratory the ultra-centrifugal analyses were carried out. They also acknowledge Dr. C. Burvenich, Mrs. M. Onghena-Anaf, Mrs. L. De NeveVan Lancker, Mrs. G. Vranken-Verhelst and Mrs. M. Buelens-Van Haute for skilled technical assistance. a Laboratory of Veterinary Physiology. State University Centre of Antwerp. 3 Laboratory of Chemical Analysis of Food from Animal Origin. Veterinary Faculty of the University of Ghent. 4 Department of Surgery. Veterinary faculty of the 19% higher than could be accounted for by secretion as milk lactose. Uptake of plasma triglycerides (TG) accounted for 45% of milk TG. The majority of the TG taken up by the udder was derived from the low density lipoprotein (LDL) fraction.

Revue bibliographique : Variations quantitatives et métabolisme des lipides dans les tissus adipeux et le foie au cours du cycle gestation-lactation 2e partie : chez la brebis et la vache

“…La Sato, 1977: Bernal-Santos, 1982 fig. 9 Armstrong et Prescott, 1971 ;Patterson et Linzell, 1974 ;Young, 1977 ;Peeters et a/., 1979 ;Thilsted, 1985a (Lindsay, 1971(Lindsay, , 1979Baird et al, 1975Baird et al, , 1980Baird et al, , 1983Lomax et al, 1979 ;Kenna et al, 1981 ;Aiello et al, 1984) et ils sont corrélés au niveau de production laitière (Lomax et .…”

Quantitative aspects of blood and amino acid flows in cattle

“…A set of 86 observations from 26 publications on plasma free amino acid extractions in lactating cows were collected (Ahrar and Schingoethe, 1979;Austin et al, 1991;Bickerstaffe et al, 1974;Block et al, 1981;Cant et al, 1993;Casper and Schingoethe, 1988;Casper et al, 1987Casper et al, , 1990Clark et al, 1974;Clark, 1975;Derrig et al, 1974;Drackley and Schingoethe, 1986;Erickson et al, 1992;Guinard and Rulquin, 1994;Hadsell and Sommerfeldt, 1988;Huber et al, 1984;Ilig et al, 1987;Kellaway et al, 1974;King et al, 1990;Klusmeyer et al, 1987;Laarveld et al, 1981;Lanham et al, 1992;Munneke et al, 1991;Peeters et al, 1979;Seymour et al, 1990;Yang et al, 1986). The information collected was the raw milk production level (MPL, L/day), milk protein content (PC, g/L), number of weeks post partum (SL, week), extraction ratio (%), and the amino acid concentration in the mammary artery.…”

“…Furthermore, RMuBF slightly decreased with progressive underfeeding in young lambs (Crompton and Lomax, 1993) but not in fasted lambs (Oddy et al, 1987;Symonds and Lomax, 1990; (Eisemann et al, 1988;Brown et al, 1991) while bovine somatotropin had no effect (Boisclair et al, 1994). Supplies of insulin parenterally (AMuBF: Huntington and Prior, 1985) (Bird et al, 1981) and RMuBF (Pethick et al, 1987) (Rasmussen, 1965) A data set of 11 publications on cows Bickerstaffe et al, 1974;Cant et al, 1993;Davis et al, 1988;Guinard et al, 1994;Hartmann and Kronfeld, 1973;Kensinger et al, 1983;Kronfeld et al, 1968;Lough et al, 1990;Metcalf et al, 1991;Peeters et al, 1979) The average ratio was 578 L of blood flow per litre of milk produced, but the range was large: from 300 for high producing cows to 1 000 for low producing cows. The same trend was found in goats by Linzell (1974 …”

Etude méthodologique sur la mesure des différences artério-veineuses mammaires chez la vache laitière

“…Two diets with 30 or 70 p. 100 concentrate ( (Zierler, 1961) (Zierler, 1961) Le sang prélevé dans la veine sous-cutanée abdominale peut être contaminé par du sang non mammaire suite à une insuffisance des valvules de la veine pudique externe (Peeters et al, 1979). Cette insuffisance n'est cependant pas très fréquente chez les vaches, qui comme dans cet essai, sont en seconde lactation (Linzell, 1974 (Linzell, 1974 (Bines et Davey, 1978) ou encore comme dans cet essai elles n'évoluent pas (Thomas et Kelly, 1976).…”