Abstract The present study aimed to investigate the effects of a combination of progesterone with different doses of E-17β on following end points: (1) ovarian follicular dynamics and emergence of a new follicular wave, and (2) superovulatory response and embryo yield. In Experiment 1, 28 ewes were randomly divided into four groups (n = 7) to receive either 2.0 mg, 1.0 mg, 0.5 mg or none E-17β one day after insertion of a progesterone device. The different doses of estradiol similarly delayed the moment of follicular emergence (overall mean = 3.1 ± 1.0 days vs. control group = 0.86 ± 1.0 days; P < 0.01), but the emergence of the new wave showed greater synchronization with the 0.5 mg dosage of E-17β. In Experiment 2, sixty-two donor ewes received an internal progesterone release device (day -1) for 7 d and 1 d after the insertion of this device (day 0) were allocated randomly to receive 0.5 mg of E-17β or only the vehicle (control group). Superstimulation was initiated on day 3 with the administration of 133 mg of pFSH in eight decreasing doses. Contrary to expectations, the protocol with the administration of 0.5 mg E-17β did not improve the percentage of donors with > 2 CL, the number of CL and the production of embryos (P > 0.05). It was concluded that the combination of progesterone and 0.5 mg E-17β was more efficient in synchronizing the emergence of the new follicular wave, however this approach seems to be unnecessary in ewe’s superovulation programs.

Abstract The aim of this study was to use estrus synchronization protocols to favor fixed-time artificial insemination and consequently fixed-time embryo collection, and increase embryo production using eCG, in gits. In a cross over design, nine Piau breed gilts were subjected to 18 days of oral progesterone; P4 group did not receive any further; GnRH group received 25µg of GnRH 104 hours after the final application of P4; and eCG+GnRH group received 1000IU of eCG 24 hours after the final P4 in addition to GnRH for subsequent embryo collection, that was performed six days after first AI, by laparotomy. Artificial insemination was performed after 12 and 24 hours of estrus in P4 group, and 128 and 144 hours in GnRH and eCG+GnRH groups. The number of CL (8.6±3.9; 8.3±2.1; 26.7±15.0) and anovulatory follicles (4.3±3.7; 3.9±3.9; 17.2±9.5) was higher in the eCG+GnRH gilts (P<0.05). However, the use of 1000 IU of eCG reduced (P<0.05) the number of total structures (5.2±3.6; 5.1±3.1; 1.7±2.7), viable embryos (5.0±3.5; 4.8±3.3; 0.4±0.7), freezable embryos (3.6±3.4; 3.3±3.8; 0.1±0.3) and recovery rate (63.7±38.9; 58.6±24.7; 5.38±9.5). P4 and GnRH protocols were effective in the production and recovery of embryos. However, the use of 1000 IU of eCG, 24 hours after P4, was not effective in promoting the production of embryos, although the animals had superovulated.

Resumo O objetivo deste experimento foi avaliar o efeito da época do ano sobre a biometria testicular e qualidade do sêmen fresco e congelado de touros Pantaneiros. Seis touros foram submetidos, mensalmente, durante um ano, à mensuração testicular e à coleta e congelamento do sêmen, utilizando-se meio à base de tris-gema-glicerol. O comprimento e o volume testiculares foram maiores (P < 0,05) nos meses de junho (11,1±0,8 cm; 652,7±138,0 cm3), julho (11,0±0,9 cm; 616,4±156,2 cm3) e setembro (11,8±0,8 cm; 692,4±141,3 cm3) que em outubro (9,4±1,2 cm; 498,5±154,3 cm3) e novembro (10,3±1,1cm; 560,0±111,8 cm3). A concentração espermática foi maior (P < 0,05) no mês de agosto (1265,0±436,8 x106sptz/mL) que nos meses de outubro, dezembro e janeiro (591,6±192,0; 627,5±314,4; 502,5±172,9 x106 sptz/mL, respectivamente). Não houve efeito da época do ano sobre a qualidade do sêmen fresco e congelado (motilidade, vigor, defeitos totais e integridade acrossomal) (P > 0,05). Conclui-se que touros Pantaneiros, na região do Distrito Federal, podem ser utilizados em programas de acasalamento natural em todas as épocas do ano. Visando ao enriquecimento do Banco Brasileiro de Germoplasma Animal com maior número de doses, sugere-se o congelamento do sêmen entre os meses de junho e agosto, embora este não apresente perda de qualidade nas diferentes épocas do ano.

Abstract The purpose of this paper was to investigate the effect of the season of the year on testicular morphology, fresh and frozen/thawed semen quality from Pantaneiro bulls bred in Brasilia, DF. Six bulls were submitted, once a month for one year, to evaluation of testicular measurements, semen collection using an artificial vagina and cryopreserved with medium containing Tris-based, egg yolk and glycerol. The testicular length and volume were greater (P < 0.05) in June (11.1±0.8 cm; 652.7±138.0 cm3), July (11.0±0.9 cm; 616.4±156.2 cm3), and September (11.8±0.8 cm; 692.4±141.3 cm3) than October (9.4±1.2 cm; 498.5±154.3 cm3) and November (10.3±1.1 cm; 560.0±111.8 cm3). The sperm concentration was greater (P<0.05) in August (1265.0±436.8 x106sperm/mL) than October, December and January (591.6±192.0, 627.5±314.4; 502.5±172.9 x106/mL). There was no effect of season on the quality of fresh and frozen semen (motility, vigor, total defects and acrosome integrity) (P > 0.05). In conclusion, Pantaneiro bulls, bred in the Midwest region of Brazil, can be used in natural mating programs in all seasons. Aiming to improve the Brazilian Animal Germplasm Bank with a higher number of samples collected, we suggest that the freezing of the semen is done between June and August, although there will be no losses of semen quality at any time.

O objetivo deste trabalho foi identificar e quantificar as bactérias do sêmen fresco de ovino, avaliar o uso do higienizante Kilol-L® antes da coleta do sêmen e testar a sensibilidade das cepas bacterianas frente ao antibiograma. Foram selecionados 24 ovinos machos, clinicamente sadios, com idade média de quatro anos, da raça Santa Inês, agrupados em dois sistemas de criação: a pasto (n=12) e confinamento (n=12). Dos 120 ejaculados coletados, 99 tiveram crescimento bacteriano correspondendo a 82,5% das amostras. Os gêneros bacterianos isolados com maior frequência foram Staphylococcus spp., Bacillus spp., Streptococcus spp., Corynebacterium spp., Listeria spp.e Escherichia coli. Dos antibióticos testados, a amicacina e a gentamicina foram 100% eficazes para Bacillus spp. e E. coli. O ceftiofur foi efetivo para todas as bactérias isoladas, exceto Rodococcus equi. Streptococcus spp. foram sensíveis à ampicilina e eritromicina, Staphylococcus spp. foram sensíveis à gentamicina. O uso Kilol-L® reduziu o número de unidades formadoras de colônias (UFC/mL) do ejaculado sem prejudicar a sua qualidade. Dos antibióticos testados, ceftiofur e gentamicina foram os mais efetivos frente às cepas bacterianas isoladas. Dessa forma, a utilização desses antibióticos no meio diluidor do sêmen ovino é uma alternativa para controlar o crescimento bacteriano.

The objective of this study was to identify and quantify bacteria from fresh ram semen, evaluate the use of sanitizer Kilol-L® prior to semen collection, and test the sensitivity of bacterial strains against antibiotics. We selected 24 Santa Inês rams clinically healthy, at 4 years of aged, and grouped them into two systems: on pasture (n=12) and confined (n=12). The microbiological results indicated that of the total of 120 ejaculates, 99 had bacterial growth, representing 82.5% of the samples. The most frequently isolated bacteria were Bacillus spp., Corynebacterium spp., Escherichia coli, Listeria spp., Staphylococcus spp., and Streptococcus spp. From the tested antibiotics, amicacin and gentamicin were 100% effective for Bacillus spp. and E. Coli. Ceftiofur was effective for all isolates except for Rodococcus equi. Streptococcus spp. were susceptible to ampicillin and erythromycin and Staphylococcus spp. were sensitive to gentamycin. The use of Kilol-L® reduced the number of Colony Forming Units (CFU/mL) from ejaculate without damaging semen quality. From the tested antibiotics, ceftiofur and gentamicin were more effective against the isolated bacterial strains; thus the use of these antibiotics in the ram semen extender is an alternative to control bacterial growth.