scholarly journals The use of equine chorionic gonadotropin in the treatment of anestrous dairy cows in gonadotropin-releasing hormone/progesterone protocols of 6 or 7 days

2013 ◽  
Vol 96 (1) ◽  
pp. 122-131 ◽  
Author(s):  
M.A. Bryan ◽  
G. Bó ◽  
R.J. Mapletoft ◽  
F.R. Emslie
Keyword(s):  
Dairy Cows ◽  
Chorionic Gonadotropin ◽  
Gonadotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Equine Chorionic Gonadotropin

scholarly journals Effect of GnRH and D-Chloprostenol application on pregnancy and prolificacy rates on Pelibuey ewes

2013 ◽  
pp. 3612-3617 ◽  
Author(s):  
Jaime Martínez T ◽  
Oziel Montañez V ◽  
Alejandro Ley De C ◽  
Fernando Izaguirre F ◽  
María Velazco Z ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Medroxyprogesterone Acetate ◽  
Fixed Time ◽  
Average Concentration ◽  
Gonadotropin Releasing Hormone ◽  
Pregnancy Rates ◽  
Ovarian Activity ◽  
Releasing Hormone ◽  
Natural Mating ◽  
Equine Chorionic Gonadotropin

ABSTRACTObjective. Was to evaluate the effect of GnRH and D-Chloprostenol application on pregnancy and prolificacy rates on Pelibuey ewes. Materials and methods. Forty five ewes were randomly allocated to one of three treatments: T1(n=15), day 0: sponges with 65 mg medroxyprogesterone acetate (MPA) + 200 IU equine chorionic gonadotropin (eCG) and sponge removal (day 12) + breeding by natural mating (days 12-15); T2 (n=15), day 0: 50 μg gonadotropin releasing hormone (GnRH) + 7.5 mg D-Chloprostenol (day 5) + 50 μg GnRH (day 7) + insemination at fixed time (AIFT) 12 to 14 h after last injection of GnRH; T3 (n=15), 100 μg GnRH (day 0) + 7.5 mg D-Chloprostenol (day 5) + 100 μg GnRH (day 7) + AIFT 12 to 14 h after last injection of GnRH. Results. The average concentration of progesterone (P4) in blood was 1.22 ± 0.74 ng/mL, which was used to verify ovarian activity at the beginning of the treatments. 100% of the T1 ewes presented estrus, beginning at 38.4±9.56 h after sponge removal. There were differences (p<0.05) for pregnancy rates, of 60, 33.33 and 46.66% respectively, among the treatments. Prolificacy was no different (p>0.05) among the treatments where the values were 1.2, 1.4 and 1.4 lambs/ewe for T1, T2 and T3, Conclusions. The results of this study show that the use of GnRH and D-Chloprostenol did improve pregnancy rates but did not improve prolificacy in tropical ewes

Pregnancy establishment and maintenance after the administration of equine chorionic gonadotropin (eCG) associated or not with gonadotropin-releasing hormone (GnRH) after insemination in sheep

2018 ◽  
Vol 58 (10) ◽  
pp. 1802 ◽  
Author(s):  
C. García-Pintos ◽  
A. Menchaca
Keyword(s):  
Chorionic Gonadotropin ◽  
Pregnancy Outcomes ◽  
Intrauterine Insemination ◽  
Gonadotropin Releasing Hormone ◽  
Factorial Experiment ◽  
Control Group ◽  
Gnrh Analogue ◽  
Releasing Hormone ◽  
Equine Chorionic Gonadotropin ◽  
To Receive

It was recently demonstrated that equine chorionic gonadotropin (eCG) treatment 10 days after ovulation increases serum progesterone concentrations in sheep. The objective of the present study was to evaluate pregnancy outcomes induced with the administration of eCG and gonadotropin-releasing hormone (GnRH) after insemination. Three experiments were conducted in multiparous ewes that received fixed-time intrauterine insemination (Day 0) after a progesterone-based protocol for oestrus synchronisation. Experiment 1 consisted of 408 ewes, randomly assigned to three experimental groups; ewes in the first and second group received 400 IU of eCG on Day 5 and Day 10 after insemination respectively, while ewes on the third (control) group did not receive eCG. In Experiment 2, 587 ewes were randomly assigned to four experimental groups (2 × 2 factorial experiment), to receive or not 400 IU of eCG on Day 5, associated or not with 100 µg of GnRH analogue on Day 6 (i.e. 30 h after eCG administration). In Experiment 3, 715 ewes were randomly assigned to four experimental groups (2 × 2 factorial experiment), to receive or not 400 IU of eCG on Day 10, associated or not with 100 µg of GnRH analogue on Day 11 (i.e. 30 h after eCG administration). Pregnancy diagnosis was determined on Day 30 and Day 70 by ultrasonography. The eCG treatment after insemination failed to improve pregnancy outcomes in Experiments 1 and 2. However, in Experiment 3 the treatment with eCG on Day 10 enhanced pregnancy rate on Day 30, although this improvement was not maintained on Day 70, which showed greater pregnancy failure. The administration of GnRH on Day 6 or Day 11, preceded or not by eCG, did not affect any of the variables related to pregnancy. In summary, the improvement in progesterone profiles induced by eCG treatment on Day 10 after insemination, previously reported in sheep, seems to have a marginal positive effect on pregnancy establishment during the first month, which is not maintained during the second month of gestation.

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