Linked Life Data

10735094

Source:http://linkedlifedata.com/resource/pubmed/id/10735094

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-4-19
pubmed:abstractText
The objective was to compare conception rates to embryo transfer relative to AI, during summer heat stress, in lactating dairy cows. Holstein cows (n = 180; 50 to 120 d postpartum) were allocated randomly to 1 of 3 groups: artificial insemination (AI, n = 84), embryo transfer using either embryos collected from superovulated donors (ET-DON, n = 48), or embryos produced in vitro (ET-IVF, n = 48). Embryos from superovulated donors were frozen in 10% glycerol and were rehydrated in a 3-step procedure, in decreasing concentrations of glycerol in a sucrose medium before transfer. Embryos produced in vitro were frozen in 1.5 M ethylene glycol, thawed and transferred without rehydration. Blood samples were collected from AI and ET recipients on Days 0, 7 and 22 for measurement of progesterone in plasma. Conception rate was estimated for the three groups at Day 22 (progesterone > 1 ng/mL) and confirmed at Day 42 by palpation per rectum. Conception rate estimates at Day 22 did not differ among groups (AI, 60.7%; ET-DON, 60.4%; ET-IVF, 54.2%), but conception rates at Day 42 differed (AI, 21.4%; ET-DON, 35.4%; ET-IVF, 18.8%; AI versus ET: P > 0.10 and ET-DON versus ET-IVF: P < 0.05). In cows considered pregnant at 22 d but diagnosed open at 42 d, the interestrous intervals were 28.8 +/- 2.2, 35.2 +/- 3.5 and 31.6 +/- 2.9 d, respectively, for AI, ET-DON and ET-IVF groups. Transfer of embryos collected from nonheat-stressed superovulated donors significantly increased conception rates in heat stressed dairy cattle. However, transfer of IVF-derived embryos had no advantage over AI. Where appropriate mechanisms are in place to attenuate the effects of heat stress, embryo transfer using frozen-thawed donor embryos increases conception rates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0093-691X
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1161-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Conception rates after artificial insemination or embryo transfer in lactating dairy cows during summer in Florida.
pubmed:affiliation
Department of Large Animal Clinical Sciences, University of Florida, Gainesville 32611, USA.
pubmed:publicationType
Journal Article, Comparative Study