Ovarian response of Suffolk ewes to estrous synchronization using short-term protocol

The efficacy of estrus synchronization using short-term protocol was evaluated by ultrasound exams in Suffolk ewes during the pre-breeding season. The control Group (n = 12) was synchronized by treatment for 12 days with vaginal sponges impregnated with medroxyprogesterone acetate, and 400 IU eCG at sponge withdrawal. Experimental groups I, II and III kept the sponge in place for 4 days, and 100 µg of PGF2a was administered at sponge withdrawal. Additionally, Group I (n = 12) had 0.1 mg of estradiol benzoate (EB) administered during sponge placement and 50 µg of GnRH 48 hours after sponge removal. Group II (n = 6) had 35 mg of progesterone (P4) injected, and 0.1 mg of EB administered during sponge placement, 400 IU eCG at withdrawal and 48 hours after, 50 µg GnRH were administrated. Group III (n = 12) had 35 mg of P4 and 0.2 mg of EB administered at sponge placement, 400 IU eCG at withdrawal, and 50 µg of GnRH was administrated after 56 hours. Ovaries were monitored through ultrasound scanning. Concerning the first wave, no difference was detected between the control group and the experimental groups. However, the characteristics of ovulatory wave were significantly different between the groups. The duration of the follicular wave was shorter for Group III than for Group II. The follicle in Group I reached its maximum diameter before the Group II. The diameter of the follicle at the sponge withdrawal in the control group was larger than in Group I. After sponge withdrawal, the follicular growth rate was smaller in the control group than in Group III. The maximum diameter of the follicle in Group II was larger than in the other groups. The short-term protocol in which estrogen was used did not synchronize the emergence of the wave of follicular development.

Efeito do genótipo sobre a composição química e o perfil de ácidos graxos da carne de borregas

O objetivo neste experimento foi avaliar os efeitos do genótipo sobre a composição química e o perfil de ácidos graxos no músculo longissimus dorsi de borregas. Foram utilizados 36 animais dos grupos genéticos: Santa Inês (SI), Ile de France (IF), Ile de France × Santa Inês (IF × SI), Dorper × Santa Inês (DO × SI), Texel × Santa Inês (TE × SI) e Suffolk × Santa Inês (SU × SI). Os animais foram distribuídos em blocos completos casualizados, definidos de acordo com o peso e a idade inicial. Não houve efeito do genótipo sobre os teores de umidade, cinzas e proteína no músculo. A carne das borregas dos genótipos Santa Inês e Suffolk × Santa Inês apresentou menor teor de gordura em comparação à das borregas Ile de France e Ile de France × Santa Inês. Os ácidos graxos identificados em maiores proporções no músculo foram o ácido oleico (C18:1cis), ácido palmítico (C16:0) e ácido esteárico (C18:0). No grupo genético Ile de France × Santa Inês, a relação entre os ácidos graxos poliinsaturados e saturados foi menor que nas borregas Santa Inês e Suffolk × Santa Inês. O genótipo Santa Inês e o cruzamento Suffolk × Santa Inês tem potencial para produção de carne de melhor valor nutricional, devido ao menor teor de gordura e à melhor relação entre ácidos graxos poliinsaturados e saturados.