Characterization of the follicular dynamic patterns in a red flemish herd in Southern Brazil
Goetten, André LucioMezzalira, AlceuZago, Fabiano CarminattiPortela, Valério Marques
Background: The Flemish Red is one of the oldest breeds of French cattle and, in France, the crosses with other red breeds and replacing them with more productive breeds caused a severe reduction in the number of purebred Flemish Red animals. Due to this drastic decrease in the Flemish Red population, this breed is at risk of extinction. The objective of the present study is to describe follicular development and serum progesterone (P4) profiles in Flemish Red cows raised in Southern Brazil for the improvement of reproductive management of this breed, considering that these animals may exhibit traits which disappeared in European animals due to genetic dilution.Materials, Methods & Results: The estrus cycles of two groups of post-pubertal non-lactating Flemish Red (FR, n = 7) and Holstein (HOL, n = 7) cows were synchronized with a Prostaglandin F2α analog. From the day of estrus, the ovaries were evaluated by transrectal ultrasound every 24 h for 21 days or until the detection of the second ovulation. The diameters of the dominant follicle (DF) and subordinate follicles (SF) were recorded according to the day of the estrus cycles and analyzed based on the diameter of both DF and SF on the day of follicular emergence, the day and diameter of DF on the day of divergence, daily growth rates of DF and FS, and the maximum diameter of both the ovulatory follicle and the dominant non-ovulatory follicle (DNOF). Samples of blood were collected every five days for P4 measurement (RIA). During emergence of the first follicle wave, the DF measured 3.97 ± 0.19 mm for FR and 4.00 ± 0.35 mm for HOL, while the SF reached 3.40 ± 0.22 mm in FR and 3, 07 ± 0.26 mm in HOL. The daily follicle growth rates was 1.10 ± 0.04 mm for DF and 0.67 ± 0.06 mm for the SF in FR, and were 1.01 ± 0.05 mm for DF and 0.72 ± 0.09 mm for the SF in HOL.[...](AU)
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