Document Detail


Machine milking of Ostfriesian and Lacaune dairy sheep: udder anatomy, milk ejection and milking characteristics.
MedLine Citation:
PMID:  9161910     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Mammary cistern anatomy derived from ultrasound measurement, milk ejection in response to exogenous oxytocin and oxytocin release and milking characteristics with and without manual prestimulation in early (months 2-4) and late (months 5-8) lactation were investigated in Lacaune and Ostfriesian dairy ewes. Vertical ultrasound cisternal cross sections of the cisternal cavities did not differ in the two breeds, whereas the cisternal area fraction located lower than the exit into the teat channel was larger in Ostfriesian than in Lacaune sheep. The cisternal area enlarged within 1 min in response to i.v. oxytocin injection, indicating milk ejection. During milking, oxytocin concentrations in Lacaune generally increased dramatically within 0.5 min from the start of prestimulation or milking, whereas only slight or no oxytocin release was detected during milking without prestimulation in Ostfriesian ewes. Prestimulation induced oxytocin release in Ostfriesian sheep within 1-2 min after the start of milking, indicating delayed response to stimulation. Two peaked milk flow curves were observed when oxytocin release and milk ejection occurred only after removal of cisternal milk. This type of milk flow was more frequent in Ostfriesian than in Lacaune ewes and was reduced in both breeds by prestimulation, while the frequency of one peaked milk flow curves increased. During the course of lactation, milk yield, main milk fraction and milk flow rates decreased, while stripping yield was almost unchanged. Although milk yield was similar in both breeds, milk flow was lower and stripping yield was higher in Ostfriesian than in Lacaune ewes. We conclude that milk ejection in ewes occurred in response to elevated oxytocin concentrations. In Ostfriesian ewes reduced and delayed oxytocin response to teat stimulation resulted in milk ejection only during stripping. Therefore, and probably because a larger volume of the cistern was located below the teat exit in the Ostfriesian breed, stripping yield was higher in Ostfriesian than in Lacaune sheep.
Authors:
R M Bruckmaier; G Paul; H Mayer; D Schams
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of dairy research     Volume:  64     ISSN:  0022-0299     ISO Abbreviation:  J. Dairy Res.     Publication Date:  1997 May 
Date Detail:
Created Date:  1997-08-11     Completed Date:  1997-08-11     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985125R     Medline TA:  J Dairy Res     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  163-72     Citation Subset:  IM    
Affiliation:
Institut für Tierzucht, Universität Bern, Schweiz.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Breeding
Dairying / instrumentation*
Equipment Design
Female
Lactation / drug effects,  physiology*
Mammary Glands, Animal / anatomy & histology*,  physiology*,  ultrasonography
Milk Ejection / drug effects,  physiology*
Oxytocin / blood
Sheep / anatomy & histology*,  blood,  physiology*
Time Factors
Vasopressins / pharmacology,  physiology
Chemical
Reg. No./Substance:
11000-17-2/Vasopressins; 50-56-6/Oxytocin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Current concepts in cardiopulmonary resuscitation.
Next Document:  Influence of supplementary fish oil and rumen-protected methionine on milk yield and composition in ...