Suplementação com progesterona injetável de longa ação em cabras boer após monta natural

Abstract

The study aimed to evaluate the effect of progesterone supplementation (P4) long acting injectable after natural mating on pregnancy rate and litter size of Boer goats. Conducted in two experimental steps were used twenty-six goats Boer, with averagebody condition score of 3.5 ± 0.1; average weight of 50 ± 0.2kg and age between 2 and 4 years previously selected by gynecological examination with ultrasound transrectal aid. During the experimental period the animals were subjected to extensive system, Buffel grass grazing (Cenchrus ciliaris), mineral salt and water ad libitum. All females received on day zero (D0) intravaginal sponges impregnated with 60mg of medroxyprogesterone acetate (MAP) (Progespon®, Syntex SA, Argentina), plus 0.25 mg oxytetracycline acetate (Terramicina®, Zoetis, Brazil). In D6, the sponges were removed and then applied 2.5 mg of a synthetic analogue of prostaglandin F2á the dinoprost tromethamine (Lutalyse®, Zoetis, Brazil) and 300 IU (1.5 mL) of equine chorionic gonadotropin (Novormon®, Zoetis, Brazil), Brazil), intramuscularly (IM). Thirty-six hours after removal of the intravaginal sponge was administered 12,5μg (0.5mL) GnRH (Gestran plus®, Agroline, Brazil), intramuscularly as ovulation inducer. The estrus detection management was performed by a player. For the toppings were used four male fertility proven with body condition score of 3.5 average and average age of three years. The male: female proportion was six females to one male. On the fourth day after the toppings, the goats were randomized into two groups (G), as follows: G1 (n = 13) Control group - no supplementation injectable P4 and G2 (n = 13): supplemented with 0.75 mg P4 injectable long-acting (Sincrogest injetável®, Ouro Fino, Brazil), IM. The pregnancy rate was held at 30 and 60 days after coverage by transrectal ultrasound examination. The prolificacy data were obtained by the average number of births goats for parity. The completely randomized design was used to evaluate experimental stage effect we used the general linear model, the data did not show normal distribution by the Shapiro-Wilk test and were analyzed using the Mann-Whitney test at 5% probability. There effect in batch experimental stages (P> 0.05). There was no difference between groups (P> 0.05) pregnancy rate at 30 days (73.0%) at 60 days (69.0%) and prolificacy (1.00 ± 1.25 born goats) . Thus, it is not recommended supplementation with injectable P4 long action on the fourth day after the coverage, not to improve the pregnancy rate and litter size of Boer goats.