HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Donke, J. D. Search for Related Content PubMed Articles by Donke, J. D.

Lactation Studies. I. Effects upon Milk Ejection in the Bovine of Various Injection Treatments Using Oxytocin and Relaxin¹

Dairy Husbandry Department, University of Minnesota, St. Paul

ABSTRACT

A cow became unable, in most instances, to eject milk normally. Oxytocin was administered to this cow intravenously, to study milk ejection. Six hundredths I. U. oxytocin was the least amount that caused partial milk ejection, whereas 0.12 to 0.25 I. U. caused normal ejection. Amounts up to ten units were increasingly more effective. Small amounts of oxytocin were more effective in ejecting milk when injected rapidly rather than slowly. However, there was little difference resulting from two 0.25 I. U. injections within a few minutes, and one 0.5 I. U. Complementary milk increased after a second injection of oxytocin, but decreased in per cent of total milk, and the fat per cent was unchanged as the time between injections increased from one to two milking intervals. Milk from the cistern of the udder increased in volume before milk ejection at milkings subsequent to oxytocin treatment, and decreased in fat as the time extended from one to two milkings and as the amount of oxytocin decreased. More complementary milk, higher in fat, was collected from certain amounts of oxytocin, divided into two injections given at one milking, if the most effective injection was given last. Relaxin was tested for milk ejection properties, and from 750 to 1,800 G.P.U. injected intravenously into three cows on two occasions did not cause noticeable milk ejection.

¹ Journal Series Paper No. 23 of the Georgia Agricultural Experiment Station, Athens.

² This work was done while the author was a member of the Dairy Department, University of Georgia, Athens.