[Changes in the conditions of milk extraction as affected by a beta mimetic (isoprenaline) administered by intrajugular route during mechanical milking of cows].
Between days 80 and 105 of lactation, 11 FFPN cows (table 1) received an intrajugular injection of either 0.9% NaCl or 0.3 mg of isoprenaline (IPN = beta-receptor agonist). Each of the two treatments was repeated at least 7 times by giving NaCl and IPN on successive, alternate days. IPN: - did not change either the total milk yield of the morning milking (13.5 l vs 13.37 l with NaCl) or the volume of milk obtained by stripping (0.460 l vs 0.447 l with NaCl), although individual responses varied considerably (table 3); - significantly increased milk flow by about 25% because it reached 1.144 l/min/quarter after IPN administration vs 0.929 l/min/quarter after NaCl injection (table 4). These results confirm our previous observations concerning milk loss between milkings (Bernabé and Peeters, 1980), i.e. the stimulation of smooth muscle beta-receptors enhances milk flow.
D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D007275:Injections, Intravenous; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology*; D007601:Jugular Veins; D007774:Lactation / Q000187:drug effects*; D011247:Pregnancy
D007545:Isoproterenol
Modifications des conditions d'extraction du lait sous l'effet d'un beta-mimétique (isoprénaline) administré par voie intrajugulaire pendant la traite mécanique de la vache.