β-carotene and FSH-P effects on follicular dynamics and embryo quality in Mangalarga Marchador mares. / Efeito do Beta Caroteno e do FSH - P sobre a dinÃmica folicular e qualidade embrionÃria em Ãguas mangalarga machador.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The objective was to evaluate the effect of β-carotene on superovulated mare embryo production and quality, as well as to asses FSH-P (FolltropinÂ) hability to induce superovulation. Sixteen Mangalarga Marchador brees donor mares were used, aged between 4 and 18 years, with sound reproductive history. Two β-carotene intra muscular dosages were tested (800 and 1200 mg), 15 days post ovulation in mares superovulated or not with Folltropin (Vetrephan- Belleville, Canada). Superovulation was attained with two daily injections at 8:00 and 18:00 h on days 15 through 20 after ovulation or until the detection of one or more follicles larger than 3,5 cm in diameter. Animals were allocated randomly to one of six treatments: 1 (n=8) â control; 2 (n=8) â superovulation; 3 (n=4) â 800 mg of β-carotene; 4 (n=4) â 1200 mg of β-carotene; 5 (n=4) â superovulation + 800 mg of β-carotene; 6 (n=4) â superovulation + 1200 mg of β-carotene. Mares were flushed six days post ovulation. Since there were no differences or interactions between treatments, the main effects of superovulation (n=16) and β-carotene supplementation (n=16) were tested against no superovulation (n=16) and no supplementation (n=16). Mean follicle number was greater (p=0.075) for superovulated (3,19  0.34) compared to controls (1.87  0.34) and there was no effect (p=0.50) of β-carotene supplementation (2.69  0.34) compared to controls (2.37  0.34). Ovulation number did not vary (1.00  0.00) between main effects. There was no effect of superovulation (8.00  0.46 d versus 8.25  0.46 d; p=0.80) or supplementation (8.06  0.46 d versus 8.18  0.46 d; p=0.90) on estrus length. Ovulatory mean follicle diameter did not differ between main effects, which ranged from 4.50  0.18 to 4.62  0.18 cm across all treatments. Embryo quality was better (p=0.041) on supplemented (1.22  0.22) versus non supplemented (2.62  0.22) mares, but similar (p=0.20) between superovulated (1.47  0.21) and non-superovulated (2.37  0.22). Follicular growth was not different between the main effects tested (p0.05) but was positively and linearly correlated with time for either superovulated (R2 = 0.95), non-superovulated (R2 = 0.92), supplemented (R2 = 0.94) and non- supplemented (R2 = 0.95) mares. In conclusion, β-carotene supplementation improved embryo quality. The superovulatory protocol used in this study was associated with a greater number of palpable follicles, but this had no reflex on the number ovulations.

ASSUNTO(S)

equino fsh-p embryo quality zootecnia equine beta carotene qualidade embrionÃria beta caroteno

ACESSO AO ARTIGO

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