scholarly journals Short communication: Presynchronization for timed artificial insemination in grazing dairy cows by using progesterone for 14 days with or without prostaglandin F2α at the time of progesterone withdrawal

2012 ◽  
Vol 95 (9) ◽  
pp. 5102-5108 ◽  
Author(s):  
R.C. Escalante ◽  
S.E. Poock ◽  
D.J. Mathew ◽  
W.R. Martin ◽  
E.M. Newsom ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Artificial Insemination ◽  
Short Communication ◽  
Prostaglandin F2α ◽  
Timed Artificial Insemination ◽  
Grazing Dairy Cows

7 COMPARISON OF TIMED ARTIFICIAL INSEMINATION PROTOCOLS USING PROSTAGLANDIN F2α+ESTRADIOL OR PROSTAGLANDIN F2α+ESTRADIOL+GONADOTROPIN-RELEASING HORMONE IN DAIRY COWS

2012 ◽  
Vol 24 (1) ◽  
pp. 115
Author(s):  
J. K. Jeong ◽  
H. G. Kang ◽  
I. H. Kim
Keyword(s):  
Dairy Cows ◽  
Pregnancy Rate ◽  
Artificial Insemination ◽  
Prostaglandin F2α ◽  
Pregnancy Rates ◽  
Gnrh Analogue ◽  
Chi Square ◽  
Array Transducer ◽  
Chi Square Test ◽  
Timed Artificial Insemination

This study compared pregnancy rates following 2 timed artificial insemination (TAI) protocols using PGF2α + oestradiol or PGF2α + oestradiol + GnRH in dairy cows. Four hundred fifty-five Holstein dairy cows, 2.2 ± 0.1 in parity, 148.3 ± 3.6 days in milk, with corpus luteum of greater than 20 mm diameter confirmed by ultrasonography (Tringa Linear with 5.0 MHz array transducer; Esaote Pie Medical, Maastricht, the Netherlands) were randomly divided into two treatments: an injection of 500 μg of cloprostenol, PGF2α analogue (Iliren cycle BP®, Intervet International GmbH, Unterschleissheim, Germany) and an injection of 2 mg of oestradiol benzoate (EB, SY Esrone, Samyang, Seoul, Korea) 36 h later (PGF2α + EB group, n = 257), or an injection of 500 μg of cloprostenol, an injection of 2 mg of EB 36 h later and an additional injection of 100 μg of gonadorelin, GnRH analogue (Godorel, Uni-Biotech Co., Ltd., Korea) 24 h later (PGF2α + EB + GnRH group, n = 198). All cows in the two groups received TAI 24 h after the EB injection. Pregnancy was determined at 40 to 50 days after TAI by using both ultrasonography and rectal palpation. Pregnancy rates between the PGF2α + EB and PGF2α + EB + GnRH groups were compared by the chi-square test using the SAS program (version 9.1: SAS Institute Inc., Cary, NC, USA). Pregnancy rate following TAI did not differ between the PGF2α + EB (32.7%) and PGF2α + EB + GnRH groups (34.9%; P > 0.05). In conclusion, addition of GnRH for TAI protocol using PGF2α + oestradiol did not improve pregnancy rate in dairy cows.

scholarly journals Effects of presynchronization and length of proestrus on fertility of grazing dairy cows subjected to a 5-day timed artificial insemination protocol

2012 ◽  
Vol 95 (5) ◽  
pp. 2513-2522 ◽  
Author(s):  
E.S. Ribeiro ◽  
A.P.A. Monteiro ◽  
F.S. Lima ◽  
H. Ayres ◽  
R.S. Bisinotto ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Artificial Insemination ◽  
Timed Artificial Insemination ◽  
Grazing Dairy Cows
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