[Milk ejection in goats and its influencing by feed].
By means of an experimental i.v. and i.m. oxytocin administration the quantitative relation between the amount of oxytocin and the quantity of ejected milk in goats was confirmed. With increasing oxytocin doses the latency period after the i.v. administration shortened, from 0.33 min. after 50 mU to 0.21 min. following 1000 mU. After the 2000 mU dose the latency period did not substantially change any more (0.18 min). The situation was nevertheless different after the i.m. oxytocin administration. No ejection followed after the 50 mU dose. Beginning with the 500 mU dose the latency period shortened, from 2.91 min. to 1.30 min. after the 2000 mU dose. With both administration manners the ejection time was prolonged up to the 1000 mU dose, then it did not substantially change. Similarly also the amount of ejected milk increased with the two administration methods up to 1000 mU, amounting to 20.6% after the i.v. and to 17.9% after i.m. administration. After 2000 mU the amount of milk ejected failed to substantially change, amounting to 19.4% with both administration manners. In experiments with manual udder stimulation with respect to feeding, the stimuli during feeding were found to influence the course of the milk ejection reflex. As compared with the pre-feeding experiments, the latency period after feeding was prolonged from 0.83 min. to 1.49 min; the amount of alveolar milk expressed in per cent of the total milk yield obtained decreased from 18.9 to 7.9%, and the ejection time shortened from 2.29 to 0.70 min. In the study the effect of various feeds on the alveolar milk ejection was also followed. Water administration did not call forth dropping off of the milk. Feeding hay called forth the ejection of 2.5% of alveolar milk occurring after an 0.25 min. latency period. Pollard provoked the ejection of 3% and the ejection time shortened from 2.29 toats (20%) can at least partially be ascribed to milk release during food intake.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior; D005260:Female; D006041:Goats; D007774:Lactation; D008893:Milk Ejection / Q000187:drug effects; D010121:Oxytocin / Q000494:pharmacology; D011247:Pregnancy
D010121:Oxytocin
Ejekce mléka u kozy a jeji ovlivnĕni krmivem