ESTRADIOL AND GNRH ON OVULATION INDUCTION FOR ESTRUS SYNCHRONIZED CROSSBRED COWS<sup>1</sup>

OLIVEIRA, FABRÍCIO ALBANI; ALMEIDA, ÍTALO CÂMARA DE; PENITENTE FILHO, JURANDY MAURO; TORRES, CIRO ALEXANDRE ALVES

doi:10.1590/1983-21252020v33n325rc

Acessibilidade / Reportar erro

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Veterinary Medicine • Rev. Caatinga 33 (3) • Jul-Sep 2020 • https://doi.org/10.1590/1983-21252020v33n325rc copy

ESTRADIOL AND GNRH ON OVULATION INDUCTION FOR ESTRUS SYNCHRONIZED CROSSBRED COWS¹

ESTRADIOL E GNRH NA SINCRONIZAÇÃO DO ESTRO E INDUÇÃO DA OVULAÇÃO DE VACAS MESTIÇAS

Authorship SCIMAGO INSTITUTIONS RANKINGS

ABSTRACT

Estradiol benzoate (EB), estradiol cypionate (EC), and gonadotrophin releasing hormone (GnRH) were evaluated as ovulation inducers for TAI of crossbred lactating cows. In experiment I (n = 45), the follicular dynamics was evaluated, while in experiment II (n = 171) the reproductive efficiency was evaluated. All females were submitted to a synchronization protocol: insertion on day 0 (D0) of intravaginal progesterone -release intravaginal device (PRID; 1g) plus administration of EB 2mg; D8, PRID removal, administration of 0.150mg PGF2α and 400 IU of eCG, and cows were allocated into three treatments: 1) TEB9 - IM administration of 1mg EB on D9 and AI performed 52 hours after PRID removal; 2) TEC - IM administration of 1mg EC on D8 and AI performed 48 hours after withdrawal of PRID; and 3) TGnRH - administration of 100pg GnRH on D10 and AI performed 52 hours after removal of PRID. The follicular growth rate was lower in the EC group (p <0.05). There was no effect of treatments on ovulation and pregnancy rates (p >0.05). The use of EB, EC, and GnRH as ovulation inducers in the TAI protocol did not show marked differences in the evaluated patterns of follicular dynamics and pregnancy.

Keywords:
Biotechnology; Estradiol benzoate (EB); Estradiol cypionate (EC); Reproduction

	Number of follicles
Item	< 6 mm	6 to 8 mm	> 8 mm	Total
		TREATMENT
TGnRH	11.9 ± 1.1 ^a	0.7 ± 0.1 ^a	0.6 ± 0.1 ^a	13.2 ± 1.1 ^a
TEB9	11.2 ± 0.9 ^a	0.5 ± 0.1 ^a	0.8 ± 0.1 ^a	12.4 ± 0.9 ^a
TEC	13.7 ± 1.0 ^a	0.6 ± 0.1 ^a	0.7 ± 0.1 ^a	15.1 ± 1.0 ^a
		DAY
0	12.0 ± 1.2 ^b	0.8 ± 0.1 ^a	0.2 ± 0.1 ^b	13.0 ± 1.2 ^a
8	12.4 ± 1.0 ^a	0.7 ± 0.2 ^a	0.9 ± 0.1 ^a	14.0 ± 1.1 ^a
10	12.5 ± 0.8 ^a	0.2 ± 0.1 ^b	1.0 ± 0.1 ^a	13.8 ± 0.8 ^a

Treatment	Follicular growth rate (mm/day)	Interval to ovulation
Treatment	Follicular growth rate (mm/day)	PRID Removal (h)	TAI (h)
TGnRH	1.9± 0.2 ^a	66.7 ± 1.3 ^a	14.8± 1.5 ^a
TEB9	1.5± 0.2 ^a	64.4 ± 0.7 ^ab	12.4± 0.7 ^a
TEC	0.7± 0.2 ^b	61.4 ± 1.0 ^b	12.8± 1.2 ^a
Mean	1.4 ± 0.1	63.1 ± 0.6	13.2 ± 0.6

Diameter (mm) of the largest follicle			p-value
TGnRH	TEB9	TEC	0.4605
10.7 ± 0.5 ^a	11.4 ±0.5 ^a	11.0 ± 0.4 ^a	0.4605

Day 8 9.7 ± 0.3 ^b		Day 10 12.5 ± 0.3 ^a	<0.0001

Treatment	Ovulation rate (%)	Pregnancy rate (%)
TGnRH	93.3 (14/15) ^a	51.9 (27/52) ^a
TEB9	100.0 (15/15) ^a	62.3 (38/61) ^a
TEC	93.3 (14/15) ^a	37.9 (22/58) ^a
Mean	95.6 (43/45) ^a	50.9 (87/171) ^a

Universidade Federal Rural do Semi-Árido Avenida Francisco Mota, número 572, Bairro Presidente Costa e Silva, Cep: 5962-5900, Telefone: 55 (84) 3317-8297 - Mossoró - RN - Brazil
E-mail: caatinga@ufersa.edu.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Corresponding author

Brasil

Brasil

ESTRADIOL AND GNRH ON OVULATION INDUCTION FOR ESTRUS SYNCHRONIZED CROSSBRED COWS1

ESTRADIOL E GNRH NA SINCRONIZAÇÃO DO ESTRO E INDUÇÃO DA OVULAÇÃO DE VACAS MESTIÇAS

ABSTRACT

ESTRADIOL AND GNRH ON OVULATION INDUCTION FOR ESTRUS SYNCHRONIZED CROSSBRED COWS¹