Reversible Techniques of Ruffian in Sheep (Ovis aires)

Background: The use of teaser rams is an essential practice for detecting estrus in ewes as well as for accelerating puberty and synchronizing ovulation in the animal. There are several methods for preparing teasers, and the method used should be based on an assessment of the producer’s requirements. The ideal technique should be low cost and safe, ensuring the non-fertilization of ewes. This study evaluated the feasibility and effectiveness of two reversible teaser preparation techniques using a reversible plastic clamp. The techniques were compared in terms of functionality, possible post-surgical complications, and hematological changes of the rams as well as durability and reversibility.Materials, Methods & Results: Twelve healthy rams, aged 14-20 months, were divided into two groups (G1 and G2). Blood samples were collected through the jugular vein to perform the following analyses: blood count, total plasma protein, and fibrinogen. Following local infiltrative anesthesia with 5.0 mL 2% lidocaine without vasoconstrictor, the procedure was performed as follows: in G1, the preputial ostium was partially closed, and in G2, sigmoid flexure was performed in the cranial region, approximately 5-8 cm immediately caudal to the scrotal sac. In the postoperative period, 20 mg/kg oxytetracycline and 2.2 mg/kg flunixinmeglumine were intramuscularly administered as a single dose. The wounds were dressed, sprayed with repellent, and allowed to heal for seven days. The procedures in both groups were simple to perform, low cost, and low risk; caused minimal tissue injury; enabled rapid recovery; promoted little or no stress to the animals; are reversible; and left no complications. The animals of both groups satisfactorily identified the females in estrus during the three-month experimental period, maintained libido, and failed to mate with any female. The blood count levels remained within normal range in both groups evaluated at different time intervals. Hyperfibrinogenemia was observed in four animals of G1 and in three animals of G2 at T2, with a mean level of 600 mg/dL. However, the values returned to normal at T3 in both G1 and G2, when the mean observed fibrinogen level was 400 mg/dL.Discussion: Since these are simple, rapid procedures with low tissue injury and a simple anesthetic protocol, the animals showed rapid recovery, without intra or postoperative complications, enabling the immediate initiation of work. The techniques, therefore, demonstrate several advantages over the other techniques described above. It is estimated that the techniques used in this study are more economically viable than other techniques described in the literature, which require medium to high complexity procedures and long postoperative treatments and carry the risk of affecting the animal’s libido, making the animal unviable and more liable to be disposed. However, disposing of such animals represents great losses, as it interferes with the reproductive management and pregnancy of several females on the farm. In addition, the conventional techniques are irreversible, which means that these animals cannot be used for other purposes. The reversible techniques presented in this study allowed the teasers to successfully identify females in heat without mating with them because there was no exteriorization of the penis. The results of the blood count confirm that the procedures did not generate extensive tissue lesions, stress, pain, inflammation, or infection

Prostaglandina F2α ou benzoato de estradiol para induzir a ovulação em vacas leiteiras inseminadas em tempo fixo

The objective of this work was to compare two types of ovulation inducers – estradiol benzoate (EB group) or prostaglandin F2α (PG group) –, in postpartum dairy cows subjected to timed artificial insemination (TAI). Lactating Holstein‑Gir crossbred cows (n=118) with 60 to 120 days of milk production were used in this study. All cows were treated with an intravaginal progesterone‑releasing device (CIDR) plus 2 mg of estradiol benzoate (EB) on day 0. The CIDR inserts were removed on day 9, and all cows received 500 µg sodium cloprostenol. Twenty‑four hours after CIDR removal, cows were randomly assigned into two treatment groups and were given either 1 mg of EB i.m. (EB group) or 500 µg sodium cloprostenol i.m. (PG group). TAI were performed at 52 to 54 hours, in both EB and PG groups, after CIDR removal. No differences were observed in the ovulation (85.2% vs 72.7%) and pregnancy rates (40.7% vs 38.2%) between the EB and PG groups, respectively. Fertility is similar in the TAI protocols that use prostaglandin F2α or EB to induce ovulation in lactating dairy cows.O objetivo deste trabalho foi comparar dois indutores de ovulação – benzoato de estradiol (grupo BE) ou prostaglandina F2α (grupo PG) –, em vacas leiteiras pós‑parto submetidas à inseminação artificial em tempo fixo (IATF). Neste estudo, utilizaram-se vacas Girolando lactantes (n=118) com 60 a 120 dias em lactação. Todas as vacas foram tratadas com um implante intravaginal liberador de progesterona (CIDR) associado a 2 mg de benzoato de estradiol (BE) no dia 0. O CIDR foi retirado no dia 9, e todas as vacas receberam 500 µg i.m. de cloprostenol sódico (análogo à prostaglandina F2α). Vinte e quatro horas após a remoção do CIDR, as vacas foram aleatoriamente separadas em dois grupos, que receberam 1 mg de BE i.m. (grupo BE) ou 500 µg de cloprostenol sódico i.m. (grupo PG). As IATF foram realizadas de 52 a 54 horas, em ambos os grupos, após a remoção do CIDR. Não se observaram diferenças nas taxas de ovulação (85,2 vs. 72,7%) e de prenhez (40,7 vs. 38,2%) entre os grupos BE e PG, respectivamente. A fertilidade é semelhante em protocolos de IATF que utilizam prostaglandina F2α ou BE para induzir a ovulação em vacas leiteiras em lactação