HOME HELP CONTACT US 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 McNEILLY, A. S. Search for Related Content PubMed Articles by McNEILLY, A. S.

Thirty-six series of serial jugular blood samples were collected from 12 goats during suckling during the first 3 weeks of lactation and the transient appearance of oxytocin (5–86 µu./ml plasma) was detected in 24 of the series. Blood oxytocin was assayed on the lactating guinea-pig mammary gland. Forty series of serial blood samples were also collected from 12 goats during hand-milking over the first 6 weeks of lactation and the transient appearance of oxytocin (5–160 µu./ml plasma) was observed in 25 of these.

The results indicated that: (1) oxytocin may be released at any time during the suckling or milking process; (2) in only 16% of experiments where oxytocin was released and 5·6% of all experiments investigated could a conditioned release of oxytocin be induced in goats before suckling and in no case before hand-milking despite a vigorous and prolonged conditioning period; (3) there is a large degree of variability in the pattern of oxytocin release between animals and between individual suckling and milking episodes in the same animal; (4) suckling and hand-milking are equally effective in causing the release of oxytocin; (5) stimuli arising during various stages of the suckling and hand-milking routines may be assigned a figure indicative of the relative effectiveness of these stimuli in terms of percentage probability in causing oxytocin release; (6) there is a greater probability of oxytocin release occurring before suckling than before hand-milking; (7) there is a very marked similarity in the pattern of oxytocin release both during and after teat stimulation in response to suckling and milking stimuli; (8) there is a greater probability of oxytocin being released in response to hand-milking during early lactation than during late lactation; (9) the milk-ejection reflex in the goat does not appear to be important for the achievement of normal milk yields during suckling or hand-milking.