The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle

Detalhes bibliográficos
Autor(a) principal: Ambrose,Divakar Justus
Data de Publicação: 2010
Outros Autores: Colazo,Marcos Germán, Kastelic,John Patrick
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Revista Brasileira de Zootecnia (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001300042
Resumo: Fertility of dairy cattle is generally decreasing. Overall estrus detection efficiency in lactating dairy cattle is low, as expression of estrus is often compromised. Consequently, undetected estrus, low AI-submission rates, and long inter-breeding intervals are the main contributors to poor reproductive efficiency. Although failure to become pregnant is the most common reason for culling dairy cattle, pregnancy rates could be improved by increasing the AI-submission rate through increased estrus detection efficiency, timed insemination (Timed-AI), or timed embryo transfer (Timed-ET). In these protocols, ovarian follicular development and luteolysis are controlled, culminating in synchronous ovulation in most cows. There are several modifications to improve pregnancy rates in Timed-AI protocols, e.g. presynchronization with 2 doses of PGF2a 14 d apart, and starting the Ovsynch protocol 12 d after the 2nd PGF2a. Timed-AI programs ensure a timely first breeding; this should be followed with early pregnancy diagnosis to identify nonpregnant cows, and prompt re-insemination. However, in a recent field study involving 23 dairy herds, the mean interval between 1st and 2nd breeding was 42 d; only 28% of the cows were rebred within 24 d after 1st breeding. Fortunately, there are several resynchronization protocols to reduce inter-breeding intervals. Anestrus cows, or those with cystic ovarian follicles, have a good chance of conceiving when subjected to synchronization of ovulation and Timed-AI. Furthermore, Timed-ET is a practical and viable option for synchronizing and selecting recipient cattle for embryo transfers. In summary, systematic and judicious use of Timed-AI and Timed-ET protocols can greatly enhance reproductive performance, and improve herd productivity.
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spelling The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattlecystic ovariesgonadotropin releasing hormoneporcine luteinizing hormoneprogesteronesynchronization of ovulationultrasonographyFertility of dairy cattle is generally decreasing. Overall estrus detection efficiency in lactating dairy cattle is low, as expression of estrus is often compromised. Consequently, undetected estrus, low AI-submission rates, and long inter-breeding intervals are the main contributors to poor reproductive efficiency. Although failure to become pregnant is the most common reason for culling dairy cattle, pregnancy rates could be improved by increasing the AI-submission rate through increased estrus detection efficiency, timed insemination (Timed-AI), or timed embryo transfer (Timed-ET). In these protocols, ovarian follicular development and luteolysis are controlled, culminating in synchronous ovulation in most cows. There are several modifications to improve pregnancy rates in Timed-AI protocols, e.g. presynchronization with 2 doses of PGF2a 14 d apart, and starting the Ovsynch protocol 12 d after the 2nd PGF2a. Timed-AI programs ensure a timely first breeding; this should be followed with early pregnancy diagnosis to identify nonpregnant cows, and prompt re-insemination. However, in a recent field study involving 23 dairy herds, the mean interval between 1st and 2nd breeding was 42 d; only 28% of the cows were rebred within 24 d after 1st breeding. Fortunately, there are several resynchronization protocols to reduce inter-breeding intervals. Anestrus cows, or those with cystic ovarian follicles, have a good chance of conceiving when subjected to synchronization of ovulation and Timed-AI. Furthermore, Timed-ET is a practical and viable option for synchronizing and selecting recipient cattle for embryo transfers. In summary, systematic and judicious use of Timed-AI and Timed-ET protocols can greatly enhance reproductive performance, and improve herd productivity.Sociedade Brasileira de Zootecnia2010-07-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001300042Revista Brasileira de Zootecnia v.39 suppl.spe 2010reponame:Revista Brasileira de Zootecnia (Online)instname:Sociedade Brasileira de Zootecnia (SBZ)instacron:SBZ10.1590/S1516-35982010001300042info:eu-repo/semantics/openAccessAmbrose,Divakar JustusColazo,Marcos GermánKastelic,John Patrickeng2010-08-09T00:00:00Zoai:scielo:S1516-35982010001300042Revistahttps://www.rbz.org.br/pt-br/https://old.scielo.br/oai/scielo-oai.php||bz@sbz.org.br|| secretariarbz@sbz.org.br1806-92901516-3598opendoar:2010-08-09T00:00Revista Brasileira de Zootecnia (Online) - Sociedade Brasileira de Zootecnia (SBZ)false
dc.title.none.fl_str_mv The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
title The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
spellingShingle The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
Ambrose,Divakar Justus
cystic ovaries
gonadotropin releasing hormone
porcine luteinizing hormone
progesterone
synchronization of ovulation
ultrasonography
title_short The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
title_full The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
title_fullStr The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
title_full_unstemmed The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
title_sort The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
author Ambrose,Divakar Justus
author_facet Ambrose,Divakar Justus
Colazo,Marcos Germán
Kastelic,John Patrick
author_role author
author2 Colazo,Marcos Germán
Kastelic,John Patrick
author2_role author
author
dc.contributor.author.fl_str_mv Ambrose,Divakar Justus
Colazo,Marcos Germán
Kastelic,John Patrick
dc.subject.por.fl_str_mv cystic ovaries
gonadotropin releasing hormone
porcine luteinizing hormone
progesterone
synchronization of ovulation
ultrasonography
topic cystic ovaries
gonadotropin releasing hormone
porcine luteinizing hormone
progesterone
synchronization of ovulation
ultrasonography
description Fertility of dairy cattle is generally decreasing. Overall estrus detection efficiency in lactating dairy cattle is low, as expression of estrus is often compromised. Consequently, undetected estrus, low AI-submission rates, and long inter-breeding intervals are the main contributors to poor reproductive efficiency. Although failure to become pregnant is the most common reason for culling dairy cattle, pregnancy rates could be improved by increasing the AI-submission rate through increased estrus detection efficiency, timed insemination (Timed-AI), or timed embryo transfer (Timed-ET). In these protocols, ovarian follicular development and luteolysis are controlled, culminating in synchronous ovulation in most cows. There are several modifications to improve pregnancy rates in Timed-AI protocols, e.g. presynchronization with 2 doses of PGF2a 14 d apart, and starting the Ovsynch protocol 12 d after the 2nd PGF2a. Timed-AI programs ensure a timely first breeding; this should be followed with early pregnancy diagnosis to identify nonpregnant cows, and prompt re-insemination. However, in a recent field study involving 23 dairy herds, the mean interval between 1st and 2nd breeding was 42 d; only 28% of the cows were rebred within 24 d after 1st breeding. Fortunately, there are several resynchronization protocols to reduce inter-breeding intervals. Anestrus cows, or those with cystic ovarian follicles, have a good chance of conceiving when subjected to synchronization of ovulation and Timed-AI. Furthermore, Timed-ET is a practical and viable option for synchronizing and selecting recipient cattle for embryo transfers. In summary, systematic and judicious use of Timed-AI and Timed-ET protocols can greatly enhance reproductive performance, and improve herd productivity.
publishDate 2010
dc.date.none.fl_str_mv 2010-07-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001300042
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001300042
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S1516-35982010001300042
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Sociedade Brasileira de Zootecnia
publisher.none.fl_str_mv Sociedade Brasileira de Zootecnia
dc.source.none.fl_str_mv Revista Brasileira de Zootecnia v.39 suppl.spe 2010
reponame:Revista Brasileira de Zootecnia (Online)
instname:Sociedade Brasileira de Zootecnia (SBZ)
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instname_str Sociedade Brasileira de Zootecnia (SBZ)
instacron_str SBZ
institution SBZ
reponame_str Revista Brasileira de Zootecnia (Online)
collection Revista Brasileira de Zootecnia (Online)
repository.name.fl_str_mv Revista Brasileira de Zootecnia (Online) - Sociedade Brasileira de Zootecnia (SBZ)
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