Banca de QUALIFICAÇÃO: GABRIELLY CRISTINA SANTOS NOLETO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : GABRIELLY CRISTINA SANTOS NOLETO
DATE: 22/11/2024
TIME: 09:00
LOCAL: Unir
TITLE:

Use of EC-GnRH34 timed AI protocol in crossbred Girolando dairy cows

KEY WORDS:

Fertilization, Milk, Ovulation, Pregnancy

PAGES: 45
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Despite being an activity that contributes greatly to the Brazilian economy, dairy farms face several challenges to become a technically efficient, economically viable and socially accepted activity. It is considered by many to be an activity that is harmful to the environment, becoming one of the main current challenges for the development of the activity. The adoption of biotechnologies linked to reproduction, such as timed artificial insemination (TAI) programs, has been widely studied and used in recent decades and aims to increase fertility rates within a herd, forming groups with genetically superior animals. The objective of the present study was to evaluate whether the administration of GnRH 34 hours after progesterone insert removal increases ovulation synchrony and fertility in crossbred Girolando dairy cows. A total of 226 crossbred Girolando (B.indicus x B. taurus, predominantly 5/8, ¾, and ½) females were used in this experiment. The females were subjected to an estradiol-progesterone based timed artificial insemination (TAI) program. At the intravaginal progesterone device (IPD) removal, all cows were treated with 1 mg i.m. of estradiol cypionate (Cipiotec®, Agener Uniao, Embu-Guacu, Brazil), and were divided into two groups to receive: 1) 2.5 mL of saline solution (0.9%) for the control group (EC Group, n = 111), or 2) 10.5 μg i.m. of buserelin acetate (EC-GnRH34 group; GnRH; Gonaxal, Biogenesis Bago, Buenos Aires, Argentina, n = 115) 34 hours after IPD removal. A subgroup of 30 cows was used to evaluate the time of ovulation after IPD removal. All cows were TAI 48 hours after IPD removal. The EC-GnRH34 treated cows ovulated earlier (P = 0.03) and more synchronously (P = 0.006) than cows only treated with EC. Females treated with EC-GnRH34 protocol had 42.6%, and the ones treated with EC had 35.1% of P/AI (P = 0.24). In conclusion, the results of the present study observed that the ovulation synchrony is optimized with the use of GnRH 34 h after the IPD removal. However, fertility did not change in comparison with the cows treated only with EC as ovulation inducer.

COMMITTEE MEMBERS:
Presidente - ***.305.370-** - LUIZ FRANCISCO MACHADO PFEIFER - EMBRAPA
Interno - 3063165 - DIEGO HENRIQUE DE ALMEIDA
Interno - ***.244.796-** - MAURÍCIO REGINALDO ALVES DOS SANTOS - EMBRAPA
Externo à Instituição - CARLOS EDUARDO LEONARDI - UFSM