The applications of timed artificial insemination and timed embryo transfer in reproductive management of dairy cattle
Autor(a) principal: | |
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Data de Publicação: | 2010 |
Outros Autores: | , |
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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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) instacron:SBZ |
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) |
repository.mail.fl_str_mv |
||bz@sbz.org.br|| secretariarbz@sbz.org.br |
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1750318147311763456 |