The luteolytic effects of exogenous prostaglandin F2alpha (PGF) that did and not simulate natural 13,14-dihydro-15-keto-PGF (PGFM) pulses were studied during mid-diestrus in 42 Holstein heifers. Plasma concentrations PGF assessed by assay PGFM. In experiment 1, a single intrauterine injection 4.0 mg into the uterine horn ipsilateral to corpus luteum resulted precipitous progesterone decline, whereas sequential injections 0.25 or 1.0 every 12 h stepwise decrease (P < 0.05) following each...

Follicles > or = 5 mm were ablated at 4 day post-ovulation in heifers to induce a follicular wave, and prostaglandin F(2alpha) was given 6 increase the incidence of double ovulations. Follicle diameters plasma hormone concentrations compared between single ovulators (n=12) (n=8). In ovulators, interval from follicle deviation peak pre-ovulatory LH surge shorter (1.9+/-0.2 vs 2.5+/-0.2 days; P<0.02) diameter largest smaller (12.2+/-0.5 13.3+/-0.3 mm; P<0.02). The did not differ for 24 h on...

The objective of this study was to evaluate ovarian follicular dynamics during intervals between successive ovum pick-up (OPU) and determine its effects on the number quality recovered cumulus-oocyte complexes (COCs) in Zebu cows (Bos indicus). Pluriparous nonlactating Gyr indicus; n=10) underwent four consecutive OPU sessions at 96-h intervals. growth monitored by twice-daily ultrasonographic examinations. A single dominant follicle (DF) or two codominant (CDF) follicles (>9mm) were present...

The aim of the present study was to use blood flow evaluation CL at 14 days after embryo transfer detect nonpregnant animals and optimize management bovine recipients. estrous cycle synchronized in 165 recipients, day expected ovulation considered be Day 0. Embryo performed 7 later, on 7. On 21, pregnancy diagnosed basis (DG21—predictive diagnostic). To validate this methodology, visual scores for were compared objective data extracted from ultrasound images recorded Doppler mode. size also...

Ultrasound-guided transvaginal follicle aspiration is used to recover cumulus-oocyte complexes (for IVF) and synchronize follicular wave emergence (ablation of dominant follicle). Although aspirated follicles are generally supposed undergo immediate atresia, there indications that they may remain active. The objective was evaluate the occurrence characteristics residual (RF) after in cattle. Ovarian synchronized Holstein cows (N = 13) presence (groups 1 3) or absence 2 4) norgestomet...

Most studies on granulosa cell (GC) function in cattle have been performed using GC and follicular fluid (FF) samples collected from slaughterhouse ovaries. Using this approach, the developmental stage functional status are unknown indirectly inferred, limiting data interpretation. Ultrasound-guided follicle aspiration has previously used to recover or FF samples, but was mostly carried out large follicles pools of small follicles, without recording efficiency recovery. The present study...

The objective of this work was to evaluate the effects hormonal synchronization protocols, associated or not with follicular development stimulation, on recovery oocytes and in vitro production Bos indicus B. taurus embryos, different seasons. Ultrasound-guided aspirations (n=237) were performed without pre-treatment (G1, control group) after wave (G2), follicle growth induction (G3). produced more embryos than (18.7±0.9 vs. 11.9±0.6 4.8±0.3 2.1±0.2 embryos). On average, oocyte embryo yields...

The aim of the present study was to characterise roles intrafollicular oestradiol production and granulosa cell (GC) expression LH receptor (LHR) gene its isoforms during follicular deviation in Bos indicus. Follicular wave emergence synchronised heifers from a taurus dairy (Holstein; n = 10) B. indicus breed (Gir; 10). Follicles were aspirated individually at sizes corresponding periods predeviation, postdeviation. Intrafollicular (IF-E2) progesterone (IF-P4) concentrations determined fluid...

Objetivou-se verificar a ocorrência de retenção placenta (RP) em vacas leiteiras provenientes rebanhos leiteiros comerciais da região Sul MG e Norte SP, Brasil avaliar associação entre oxitetraciclina cloprostenol para o tratamento RP.Foram utilizadas 769 gestantes.Após parto, os animais com RP (N=121) foram aleatoriamente divididos dois grupos tratamento: 1) Aplicação cloridrato oxitetraciclina, 20 mg/kg (IM) dose única; 2) inclusão duas injeções 0,530 mg cloprostenol, 48 horas intervalo ao...

O dispositivo de liberação progesterona (DLP) é muito importante em protocolos Inseminação Artificial Tempo Fixo (IATF). Representa cerca 43% dos custos e objeto estudos sobre a eficiência da sua reutilização. No entanto, perfis (P4) animais com diferentes concentrações endógenas desse esteroide não são claramente descritos. Este estudo teve como objetivo avaliar concentração sérica P4 fêmeas situações atividade luteal, tratadas DLP novo (1g P4) por 8 dias. Trinta novilhas mestiças cíclicas...

Removal of the follicular content by ultrasound-guided transvaginal follicle aspiration (TVFA) may fail to induce immediate atresia and loss function, resulting in occurrence residual follicles (RF). The aims this study were characterize blood flow RF determine effects treatment with estradiol benzoate on fate. Lactating, cyclic Holstein-Gir crossbred cows used. In Experiment 1, wave emergence (D0) was synchronized (n = 10) growth then monitored transrectal ultrasonography from D0 D8,...

The objective of this study was to evaluate by in vitro tests and vivo fertility, two concentrations egg yolk (T1 = 20% or T2 2.5%) yolk-citrate semen extender for storing goat at 5°C 24 hours. Ninety collections were performed four goats. split diluted different extenders stored refrigerator hours, until the evaluation insemination procedures. average values cooled semen, respectively, T1 motility, 68.5 ± 15.4 78.0 5.5 (p &lt; 0.05); vigor, 2.5 0.6 3.2 0.3 0.05), supravital test, 59.4 17.2...