Two trials were conducted to compare the effectiveness of fixed-time artificial insemination (AI) to AI based upon visual detection of estrus following superstimulation of donor beef cows. In Trial 1, multiparous beef cows (n = 31) were randomly allotted to one of three treatments following superstimulation and removal of an intravaginal progesterone insert (CIDR). Cows in the Control group were inseminated at 12 and 24 h after onset of estrus. Cows in the Estradiol group were injected with estradiol-17β (1 mg, im) at 12 h and inseminated at 24 and 36 h after CIDR removal. Cows in the pLH36 group were injected with porcine LH (Lutropin, 12.5 mg, im) at 24 h and inseminated at 36 and 48 h after CIDR removal. Mean numbers of viable embryos were 7.8, 3.6 and 9.6 for Control, Estradiol and pLH36 treatment groups, respectively (P > 0.10). In Trial 2, multiparous beef cows (n = 22) were randomly allotted to one of three treatments following superstimulation and removal of a CIDR. Sixteen of the cows were superstimulated a second time approximately 50 days later and allotted to one of the two treatments that differed from the initial treatment group. Cows in the Control group were inseminated at 12 and 24 h after onset of estrus. Cows in the two pLH groups were injected with porcine LH (Lutropin,12.5 mg, im) at 24 h after CIDR removal and were inseminated with either one unit of semen at 36 and 48 h (pLH36) or with two units of semen at 48 h (pLH48) after CIDR removal. Mean numbers of viable embryos were 3.0, 6.4 and 3.8 for Control, pLH36 and pLH48 treatment groups, respectively (P > 0.10). These data indicate that administration of pLH can facilitate use of fixed-time AI in superovulated beef cows without sacrificing embryo production. The second study evaluated the efficacy of resynchronizing beef cow recipients using CIDR devices for only 7 or 14 d. Recipient cows received CIDRs either on the day of transfer (n = 88) or 7 d post-transfer (n = 230). All CIDRs were removed on d 21 and cows were observed for estrus between d 22 and 24. Cows that displayed estrus were ultrasounded on d 30, those cows not pregnant that possessed a CL had an embryo transferred that day. Cows were later examined for pregnancies approximately 23 to 30 d later. There were no differences in pregnancy rates between cows with 7 or 14 d CIDRs and therefore data were combined. Pregnancy rates at two different ranches indicate that beef cow recipients can be successfully resynchronized by insertion of a CIDR without compromising pregnancy rates of transferred embryos. At Center Ranch the pregnancy rate for the first transfer was 57% while the resynchronized group that received the second transfer had a pregnancy rate of 55%. At Mound Creek Ranch the first transfer of embryos produced 59% pregnancy rates while the second transfer had a pregnancy rate of 71%. No significant differences (P > 0.05) were observed between the pregnancy rates of the initial transfer and those of the resynchronized transfer using only CIDRs, indicating that resynchronization using CIDRs can be used without reducing pregnancy rates.

Developing a single fixed-time artificial insemination (FTAI) protocol would benefit small-scale and niche market pork producers by decreasing semen costs and labor associated with detection of estrus. The objective of this study was to test the efficacy of an artificial insemination (AI) breeding system using triptorelin acetate, a GnRH agonist (OvuGel®; JBS United Animal Health, LLC, Sheridan, IN) that induces ovulation. A total of 96 sows (parity, 3.5 ± 0.2; body condition score (BCS), 2.5 ± 0.07) were weaned (h 0) after a 24.8 ± 0.6 d lactation on five participating small swine farms and allocated to one of four treatment groups: 1) TRT1: (n = 24) OvuGel applied intravaginally at h 96 and AI at h 120; 2) TRT2: (n = 24) P.G. 600® (400 IU eCG and 200 IU hCG, Merck Animal Health, Inc., De Sota, KS) injected intramuscularly at weaning, OvuGel at h 96 and AI at h 120; 3) TRT3: (n = 24) P.G. 600 at weaning, and AI at 0 and 24 h after first detection of estrus; and 4) TRT4: (n = 24) AI at 0 and 24 h after first detection of estrus. Treatments 1 and 2 were FTAI protocols with sows being inseminated without regard to estrus onset. Treatments 3 and 4 were consistent with current industry AI practices. The proportion of females displaying estrus by d 7 post-weaning was greater (P < 0.05) for sows that received OvuGel (94.5 %) compared to sows that did not receive OvuGel (82.2 %). There were no effects (P > 0.05) of P.G. 600 or P.G. 600 x OvuGel on females displaying estrus by d 7 or d 10 post-weaning. Weaning to estrus interval was decreased (P < 0.05) for sows that received P.G. 600 (4.9 ± 0.4 d) compared to sows that did not receive P.G. 600 (5.4 ± 0.4 d). There were no effects (P > 0.05) of OvuGel or P.G. 600 x OvuGel on the weaning-to-estrus interval. There were no effects of P.G. 600, OvuGel or P.G. 600 x OvuGel (P > 0.1) on pregnancy rate (total sows pregnant/inseminated) (61.2 %), total litter size (11.3), number born dead (1.0) or number of mummies (0.2). There was an effect (P < 0.05) of P.G. 600 x OvuGel on total born live (10.2). Sows treated with OvuGel had a greater number of live piglets born per semen dose (5.4) compared to sows that did not receive OvuGel (3.2) (P < 0.05). These results suggest that FTAI protocols may be employed on small-scale pig farms without compromising reproductive performance. / Master of Science / Reproductive tools such as the development of a single fixed-time artificial insemination (FTAI) protocol would benefit small scale and niche market swine producers by decreasing semen costs and labor associated with the detection of behavioral estrus or “standing heat”. OvuGel® (JBS United Animal Health, LLC, Sheridan, IN) is a gonadotropin releasing hormone (GnRH) agonist in the form of triptorelin acetate that mimics endogenous secretion of GnRH from the hypothalamus. Because the drug stimulates pituitary luteinizing hormone (LH) secretion and ovulation in weaned sows it offers potential for use in FTAI. The objective of this study was to test the efficacy of a FTAI breeding system using OvuGel to induce ovulation on five participating small-scale and niche market swine farms. A total of 96 sows (parity, 3.5 ± 0.2; body condition score (BCS), 2.5 ± 0.07) were weaned (h 0) after a 24.8 ± 0.6 d lactation and allocated to one of four treatment groups. In TRT1, OvuGel was administered 96 h after weaning with sows receiving a single insemination 22 ± 2 h later. In TRT2, sows received an intramuscular injection of P.G. 600® (400 IU eCG and 200 IU hCG, Merck Animal Health, Inc., De Sota, KS) at weaning, were given OvuGel 96 h post-weaning and were inseminated 22 ± 2 h later. Sows in TRT1 and TRT2 groups were inseminated whether behavioral estrus was exhibited or not. Weaned sows allocated to TRT3 received P.G. 600 at weaning, and once-daily estrus detection using a mature boar and females were inseminated when estrus was first detected and then again 24 h later. Sows allocated to TRT4 were given once-daily estrus detection, and inseminated at onset of estrus and again 24 h later. Treatment groups TRT1 and TRT2 represented the single, FTAI protocol whilst TRT3 and TRT4 groups were representative of current AI practices in today’s swine industry. Sows that had received OvuGel had a greater proportion of females displaying estrus by d 7 post-weaning compared to sows that did not receive OvuGel. There were no effects of P.G. 600 alone or P.G. 600 and OvuGel in combination on the proportion of females displaying estrus by d 7 or d 10 post-weaning. Weanto-estrus intervals were decreased in sows receiving P.G. 600 but not for sows receiving OvuGel or P.G. 600 and OvuGel. Reproductive performance measures such as pregnancy rates, total litter size, number of pigs born dead, or number of mummies were not affected by P.G. 600, OvuGel or the combination of P.G. 600 and OvuGel; however, there was an effect of the P.G. 600 by OvuGel interaction on total pigs born alive. Furthermore, sows treated with OvuGel had a greater number of live pigs born per semen dose compared to sows that did not receive OvuGel. These findings suggest that FTAI protocols may be used as a reproductive tool on small-scale pig farms without compromising reproductive performance.

O objetivo do presente estudo foi avaliar a viabilidade da refrigeração do sêmen bovino comparada com a criopreservação. Este estudo foi realizado em dois experimentos. No primeiro experimento foram comparados os efeitos in vitro do sêmen refrigerado em três meios diluidores comerciais a 5&deg; C por até 48 horas, e criopreservado em dois meios. Para este experimento foram utilizados ejaculados de 10 touros da raça Nelore. Cada ejaculado foi dividido em três alíquotas, sendo diluídas nos meios Botubov&reg;, Steridyl&reg; e Bovidyl&reg;. Após a diluição o sêmen foi envasado em palhetas e refrigerado nos três diluidores e criopreservado utilizando somente os meios Botubov&reg; e Steridyl&reg;. A refrigeração do sêmen foi realizada a 5&deg; C por até 48 horas em sistema passivo de refrigeração BotuFlex&reg; e a criopreservação realizada em sistema automatizado TK 4.000&reg;. O sêmen foi avaliado nos tempos 0, 24, 36 e 48 horas após a refrigeração e após a descongelação, para cada diluidor. Foram realizadas análises dos padrões de cinética espermática pelo sistema computadorizado de análise espermática (CASA, programa SCA - Sperm Class Analyser), integridade das membranas plasmática e acrossomal, potencial de membrana mitocondrial e estresse oxidativo por sondas fluorescentes, sob microscopia de epifluorescência e morfologia espermática por microspcopia de contraste de interferência diferencial (DIC). Notou-se efeito de tempo de refrigeração para os três diluidores para de 0 para 24h, se mantendo semelhante até 48 h. Os diluiores Botubov&reg; e Steridyl&reg; preservaram as características espermáticas de forma semelhante até 48 horas de refrigeração diferindo apenas na variável de velocidade curvilianear; no entanto, ambos foram superiores ao diluidor Bovidyl&reg;, para as variáveis, motilidade total, motilidade progressiva, células rápidas, velocidade curvilinear, velocidade progressiva, velocidade do trajeto, retilinearidade, integridade da membrana plasmática, alto potencial de mitocondrial e espermatozoides com membranas plasmática e acrossomal íntegras e alto potencial mitocondrial. O segundo experimento foi realizado, baseado nos resultados do primeiro experimento, para avaliar os efeitos da refrigeração e da criopreservação do sêmen sobre a fertilidade in vivo. Foram utilizados ejaculados de três touros das raças Brangus, Braford e Angus, com idade entre 5 e 7 anos. O sêmen foi colhido por meio de vagina artificial, o ejaculado foi dividido em três alíquotas, sendo duas alíquotas para refrigeração e uma para criopreservação. Para a refrigeração o sêmen foi diluído nas concentrações de 15x106 (R15) e 30x106 (R30) espermatozoides/palheta e para a criopreservação diluído na concentração de 30x106 espermatozoides/palheta (CRIO). Para todas as diluições foi utilizado o meio Botubov&reg; e o sêmen armazenado em palhetas de 0,5 mL. A refrigeração foi realizada a temperatura de 5&deg; C por 48 horas em sistema passivo de refrigeração BotuFlex&reg; e a criopreservação em sistema automatizado TK&reg;. Foram sincronizadas 552 vacas da raça Brangus em programas de inseminação artificial em tempo fixo. Os resultados da taxa de prenhez para os grupos de vacas inseminadas foram de 49,4% para R15, 43,38% para R30 e 47,59% para o sêmen criopreservado. Pode-se concluir que a refrigeração do sêmen a 5&deg; C por 48 horas resulta em taxa de prenhez semelhante às obtidas com o sêmen criopreservado, sendo que esses resultados indicam que a refrigeração por até 48 horas pode ser uma opção de uso para IATF. / The objective of the present study was to evaluate the viability of cooling bovine semen compared to cryopreservation. This study was carried out in two experiments. In the first experiment, the in vitro effects of cooled semen were compared in three commercial extenders at 5&deg; C for up to 48 hours, and cryopreserved in two extender. For this experiment were used ejaculates of 10 Nellore bulls. Each ejaculate was divided into three aliquots, being diluted in the Botubov&reg;, Steridyl&reg; and Bovidyl&reg; extenders. After dilution, the semen was cooled into three extenders and cryopreserved using the Botubov&reg; and Steridyl&reg;. Semen refrigeration was performed at 5&deg; C for up to 48 hours in BotuFlex&reg; passive refrigeration system and cryopreservation performed in TK 3.000&reg; automated system. Semen was evaluated at 0, 24, 36 and 48 hours after refrigeration and after thawing, for each diluent. The sperm kinetics of the spermatic kinetics (CASA, SCA - Sperm Class Analyzer), plasma and acrosomal membrane integrity, mitochondrial membrane potential and oxidative stress by fluorescent probes were analyzed under epifluorescence microscopy and sperm morphology By Differential Interference Contrast Microscopy (DIC). The Botubov&reg; and Steridyl&reg; diluents were very similar after 48 hours of cooling differing significantly only in the Curvilianear Velocity (VCL) 106.04 m/s and 124.56 m/s. The Bovidyl&reg; diluent yielded results significantly lower than the 48 hours of refrigeration for the variables: total motility (MT), progressive motility (MPRO), fast cells (RAP), curvilinear velocity (VCL), progressive velocity (AP), plasma membrane integrity (PI), high mitochondrial potential (AP), and spermatozoa with intact plasma and acrosomal membranes and high mitochondrial potential (PIAIA). The second experiment was carried out, based on the results of the first experiment I, to evaluate the effects of cooled and cryopreservation of semen on in vivo fertility. We used ejaculates of three bulls of the Brangus, Braford and Angus breeds of a IA center, aged between 5 and 7 years. The semen was collected by artificial vagina, the ejaculate was divided into three aliquots, two aliquots for refrigeration and one for cryopreservation. For cooling, the semen was diluted in the concentrations of 15x106 (R15) and 30x106 (R30) spermatozoa/straw, for cryopreservation diluted in the concentration of 30x106 spermatozoa / vane (CRIO). For all dilutions, the Botubov&reg; medium and the semen stored in 0.5 mL vial were used. Refrigeration was carried out at a temperature of 5&deg; C for 48 hours in BotuFlex&reg; passive refrigeration system and cryopreservation in an automated TK&reg; system. 552 Brangus cows were synchronized in fixed-time artificial insemination programs. The results of the pregnancy rate for the groups of inseminated cows were 49.4% for R15, 43.38% for R30 and 47.59% for cryopreserved semen. It can be concluded that the cooling of the semen at 5&deg; C for 48 hours results in pregnancy rate similar to those obtained with cryopreserved semen, and these results indicate that refrigeration for up to 48 hours may be an option of use for FTAI.

Foram comparadas diferentes doses de eCG e hCG associadas a dispositivos intravaginais de progesterona (DIV), para avaliar o crescimento folicular e a ovulação, bem como a taxa de prenhez após a IATF e a funcionalidade do CL 12 dias após a sincronização em búfalas, durante a estação reprodutiva desfavorável. Para tanto, foram realizados cinco experimentos. Nos experimentos 1, 2 e 4, os grupos foram estabelecidos em função da ciclicidade dos animais, avaliada pelas concentrações plasmáticas de progesterona mediante colheita de sangue por punção da veia jugular no D-10 e no D0. Nos experimentos 3 e 5, os grupos foram estabelecidos em função da condição corporal e da ordem de parto. Em todos os experimentos as búfalas receberam um DIV associado a 2mg de Benzoato de Estradiol (BE) no D0. No D9 o DIV foi retirado, e procedeu-se à administração de 0,150mg de prostaglandina (PGF). No experimento 1, as búfalas do G1 (Controle, n=9) e do G2 (eCG, n=10) receberam 1500UI de hCG no D11; o G2 recebeu também 500UI de eCG no D-9; a IATF foi realizada no D12. Nesse experimento, o diâmetro máximo do folículo dominante (DMFD) foi de 12,6 ± 3,0 e 13,4 ± 1,7mm para o G1 e o G2, respectivamente (P>0,05); o diâmetro do folículo ovulatório (DFO) foi de 14,9 ± 2,9 (G1) e de 14,0 ± 1,6mm (G2; P>0,05); o intervalo entre a retirada do DIV e a ovulação (IROV) foi de 78,0 ± 12 (G1) e 68,0 ± 9,0h (G2; P>0,05); a taxa de ovulação (TO) foi de 44,4 (G1) e 70,0% (G2; P> 0,05). A área do CL (ACL) foi de 31,6 ± 19,9 (G1) e de 29,9 ± 9,7mm2 (G2; P>0,05); a concentração plasmática de P4 (P4) foi de 1,3 ± 1,4 (G1) e 2,0 ± 1,6ng/ml (G2; P>0,05); a taxa de prenhez (TP) foi de 22,2 (G1) e 60% (G2; P=0,11). No experimento 2, as búfalas do G1 (1500 UI de hCG; n=21) e do G2 (1000UI de hCG; n=21) receberam 500UI de eCG no D9; no D11, o G1 recebeu 1500UI de hCG e o G2 1000UI de hCG. Os resultados desse experimento são relatados a seguir: DMFD de 12,4 ± 2,3 (G1) e 12,2 ± 2,5mm (G2; P>0,05); DFO de 12,6 ± 2,3 (G1) e 12,5 ± 2,7mm (G2; P>0,05); IROV de 67,7 ± 18,1 (G1) e 72,8 ± 16,7h (G2; P>0,05); TO de 67,7 (G1) e 67,7% (G2; P>0,05); ACL de 24,8 ± 9,2 (G1) e 28,3 ± 17,2mm2 (G2; P>0,05); P4 de 2,3 ± 1,4 (G1) e 2,4 ± 1,3ng/ml (G2; P>0,05). No experimento 3, os animais foram tratados de forma idêntica àqueles do experimento 2, porém as búfalas do G1 (n=83) e do G2 (n=91) receberam a IATF no D12. Nesse experimento, foi obtida TP de 53 (G1) e de 53,8% (G2; P>0,05). No Experimento 4, as búfalas do G1 (n=10) receberam 500UI e as do G2 (n=11) 400UI de eCG; os dois grupos receberam 1000UI de hCG no D11. Esse experimento teve como resultados: DMFD de 13,2 ± 1,4 (G1) e 13,8 ± 1,8mm (G2; P>0,05); DFO de 13,7 ± 1,1 (G1) e 14,2 ± 1,5mm (G2; P>0,05); IROV de 71,1 ± 11,7 (G1) e 75,0 ± 5,5h (G2; P>0,05); TO de 70,0 (G1) e 72,7% (G2; P>0,05); ACL de 28,4 ± 8,6 (G1) e 31,6 ± 10,3mm2 (G2; P>0,05); P4 de 2,7 ± 1,2 (G1) e 3,3 ± 2,9ng/ml (G2; P>0,05). No experimento 5 (G1/n=54; G2/n=51) foi adotado o mesmo protocolo do experimento 4, porém as búfalas receberam a IATF no D12. Esse experimento resultou em TP de 42,6 (G1) e 43,1% (G2; P>0,05). Assim, foi possível concluir que as concentrações de 400UI de eCG e de 1000UI de hCG, associadas ao DIV, foram suficientes para induzir o crescimento folicular, a ovulação e a prenhez em búfalas durante o período reprodutivo desfavorável. / Different dosage of eCG and hCG were compared in association to progesterone intravaginal device (IVD) in female buffalo during the off breeding season with the purpose of evaluating the follicular growing and ovulation as well as the pregnancy rate after FTAI and functionality of the CL, twelve days after the synchronization. For this, 5 experiments were done. For the establishments of the groups in the experiments 1,2 and 4 blood samples were collected for the analysis of plasmatic concentrations of P4 on D -10 and D0 to verify the cyclicity. In the experiments 3 and 5 the groups were established due body condition score and number of calving. In all the experiments the buffaloes received a IVD associated with 2mg of estradiol benzoate (EB) on D0. On D9 the IVD was extracted and it was followed by the administration of 0,150mg of prostaglandin (PGF). In the exp. 1 the buffaloes of G1 (control, n=9) and G2 (eCG, n=10) received 1500IU of hCG on D11. On G2 was administrated 500IU of eCG on D9. The FTAI was done on D12. The maximun diameter of dominant follicle (MDDF) was 12.6 ± 3.0 and 13.4 ± 1.7mm to the G1 and G2, respectively (P>0,05). The diameter of the ovulatory follicle (DOF) was 14.9 ± 2.9 (G1) and 14.0 ± 1.6mm (G2; P>0,05). The interval between the device withdrawn and ovulation (DWO) was 78.0 ± 12.0 (G1) and 68.0 ± 9.0h (G2; P>0,05). The ovulation rate (OR) was 44.4 (G1) and 70.0% (G2; P>0,05). The CL area (CLA) was 31.6 ± 19.9 (G1) and 29.9 ± 9.7mm2 (G2; P>0,05). The plasmatic concentration of P4 (P4) was 1.3 ± 1.4 (G1) and 2.0 ± 1.6ng/ml (G2; P>0,05). The pregnancy rate (PR) was 22.2 (G1) and 60% (G2; P=0,11). In the exp. 2 the buffalo females of G1 (1500IU of hCG; n=21) and G2 (1000IU of hCG; n=21) received 500IU of eCG on D9. On D11, G1 received 1500IU of hCG and G2 1000IU of hCG. The MDDF was 12.4 ± 2.3 (G1) and 12.2 ± 2.5mm (G2; P>0,05), the DOF was 12.6 ± 2.3 (G1) and 12.5 ± 2.7mm (G2; P>0,05), DWO was 67.7 ± 18.1 (G1) and 72.8 ± 16.7h (G2; P>0,05), the OR was 67.7 (G1) and 67.7% (G2; P>0,05), the CLA was 24.8 ± 9.2 (G1) and 28.3 ± 17.2mm2 (G2; P>0,05) and the P4 was 2.3 ± 1.4 (G1) and 2.4 ± 1.3ng/ml (G2; P>0,05). The exp. 3 was identical to exp.2, although the animals of G1 (n=83) and G2 (n=91) received the FTAI on D12. The PR was 53.0 (G1) and 53,8% (G2; P>0,05). In exp. 4, the animals of G1 (n=10) received 500IU and G2 (n=11) 400IU of eCG. Both groups received 1000IU of hCG on D11. The MDDF was 13.2 ± 1.4 (G1) and 13.8 ± 1.8mm (G2; P>0,05), the DOF was 13.7 ± 1.1 (G1) and 14.2 ± 1.5mm (G2; P>0,05), the DWO was 71.1 ± 11.7 (G1) and 75.0 ± 5.5h (G2; P>0,05), the OR was 70.0 (G1) and 72.7% (G2; P>0,05), the CLA was 28.4 ± 8.6 (G1) and 31.6 ± 10.3mm2 (G2; P>0,05) and the P4 was 2.7 ± 1.2 (G1) and 3.3 ± 2.9ng/ml (G2; P>0,05). In exp. 5 (G1/n=54; G2/n=51) was done the same protocol in the exp. 4, although the animals received the FTAI on D12. The PR was 42.6 (G1) and 43.1% (G2; P>0,05). Dosage of 400IU of eCG and 1000IU of hCG, associated to IVD for FTAI were enough to induce follicular growing, ovulation and pregnancy in buffalo females during the off breeding season.

Foram comparadas diferentes doses de eCG e hCG associadas a dispositivos intravaginais de progesterona (DIV), para avaliar o crescimento folicular e a ovulação, bem como a taxa de prenhez após a IATF e a funcionalidade do CL 12 dias após a sincronização em búfalas, durante a estação reprodutiva desfavorável. Para tanto, foram realizados cinco experimentos. Nos experimentos 1, 2 e 4, os grupos foram estabelecidos em função da ciclicidade dos animais, avaliada pelas concentrações plasmáticas de progesterona mediante colheita de sangue por punção da veia jugular no D-10 e no D0. Nos experimentos 3 e 5, os grupos foram estabelecidos em função da condição corporal e da ordem de parto. Em todos os experimentos as búfalas receberam um DIV associado a 2mg de Benzoato de Estradiol (BE) no D0. No D9 o DIV foi retirado, e procedeu-se à administração de 0,150mg de prostaglandina (PGF). No experimento 1, as búfalas do G1 (Controle, n=9) e do G2 (eCG, n=10) receberam 1500UI de hCG no D11; o G2 recebeu também 500UI de eCG no D-9; a IATF foi realizada no D12. Nesse experimento, o diâmetro máximo do folículo dominante (DMFD) foi de 12,6 ± 3,0 e 13,4 ± 1,7mm para o G1 e o G2, respectivamente (P>0,05); o diâmetro do folículo ovulatório (DFO) foi de 14,9 ± 2,9 (G1) e de 14,0 ± 1,6mm (G2; P>0,05); o intervalo entre a retirada do DIV e a ovulação (IROV) foi de 78,0 ± 12 (G1) e 68,0 ± 9,0h (G2; P>0,05); a taxa de ovulação (TO) foi de 44,4 (G1) e 70,0% (G2; P> 0,05). A área do CL (ACL) foi de 31,6 ± 19,9 (G1) e de 29,9 ± 9,7mm2 (G2; P>0,05); a concentração plasmática de P4 (P4) foi de 1,3 ± 1,4 (G1) e 2,0 ± 1,6ng/ml (G2; P>0,05); a taxa de prenhez (TP) foi de 22,2 (G1) e 60% (G2; P=0,11). No experimento 2, as búfalas do G1 (1500 UI de hCG; n=21) e do G2 (1000UI de hCG; n=21) receberam 500UI de eCG no D9; no D11, o G1 recebeu 1500UI de hCG e o G2 1000UI de hCG. Os resultados desse experimento são relatados a seguir: DMFD de 12,4 ± 2,3 (G1) e 12,2 ± 2,5mm (G2; P>0,05); DFO de 12,6 ± 2,3 (G1) e 12,5 ± 2,7mm (G2; P>0,05); IROV de 67,7 ± 18,1 (G1) e 72,8 ± 16,7h (G2; P>0,05); TO de 67,7 (G1) e 67,7% (G2; P>0,05); ACL de 24,8 ± 9,2 (G1) e 28,3 ± 17,2mm2 (G2; P>0,05); P4 de 2,3 ± 1,4 (G1) e 2,4 ± 1,3ng/ml (G2; P>0,05). No experimento 3, os animais foram tratados de forma idêntica àqueles do experimento 2, porém as búfalas do G1 (n=83) e do G2 (n=91) receberam a IATF no D12. Nesse experimento, foi obtida TP de 53 (G1) e de 53,8% (G2; P>0,05). No Experimento 4, as búfalas do G1 (n=10) receberam 500UI e as do G2 (n=11) 400UI de eCG; os dois grupos receberam 1000UI de hCG no D11. Esse experimento teve como resultados: DMFD de 13,2 ± 1,4 (G1) e 13,8 ± 1,8mm (G2; P>0,05); DFO de 13,7 ± 1,1 (G1) e 14,2 ± 1,5mm (G2; P>0,05); IROV de 71,1 ± 11,7 (G1) e 75,0 ± 5,5h (G2; P>0,05); TO de 70,0 (G1) e 72,7% (G2; P>0,05); ACL de 28,4 ± 8,6 (G1) e 31,6 ± 10,3mm2 (G2; P>0,05); P4 de 2,7 ± 1,2 (G1) e 3,3 ± 2,9ng/ml (G2; P>0,05). No experimento 5 (G1/n=54; G2/n=51) foi adotado o mesmo protocolo do experimento 4, porém as búfalas receberam a IATF no D12. Esse experimento resultou em TP de 42,6 (G1) e 43,1% (G2; P>0,05). Assim, foi possível concluir que as concentrações de 400UI de eCG e de 1000UI de hCG, associadas ao DIV, foram suficientes para induzir o crescimento folicular, a ovulação e a prenhez em búfalas durante o período reprodutivo desfavorável. / Different dosage of eCG and hCG were compared in association to progesterone intravaginal device (IVD) in female buffalo during the off breeding season with the purpose of evaluating the follicular growing and ovulation as well as the pregnancy rate after FTAI and functionality of the CL, twelve days after the synchronization. For this, 5 experiments were done. For the establishments of the groups in the experiments 1,2 and 4 blood samples were collected for the analysis of plasmatic concentrations of P4 on D -10 and D0 to verify the cyclicity. In the experiments 3 and 5 the groups were established due body condition score and number of calving. In all the experiments the buffaloes received a IVD associated with 2mg of estradiol benzoate (EB) on D0. On D9 the IVD was extracted and it was followed by the administration of 0,150mg of prostaglandin (PGF). In the exp. 1 the buffaloes of G1 (control, n=9) and G2 (eCG, n=10) received 1500IU of hCG on D11. On G2 was administrated 500IU of eCG on D9. The FTAI was done on D12. The maximun diameter of dominant follicle (MDDF) was 12.6 ± 3.0 and 13.4 ± 1.7mm to the G1 and G2, respectively (P>0,05). The diameter of the ovulatory follicle (DOF) was 14.9 ± 2.9 (G1) and 14.0 ± 1.6mm (G2; P>0,05). The interval between the device withdrawn and ovulation (DWO) was 78.0 ± 12.0 (G1) and 68.0 ± 9.0h (G2; P>0,05). The ovulation rate (OR) was 44.4 (G1) and 70.0% (G2; P>0,05). The CL area (CLA) was 31.6 ± 19.9 (G1) and 29.9 ± 9.7mm2 (G2; P>0,05). The plasmatic concentration of P4 (P4) was 1.3 ± 1.4 (G1) and 2.0 ± 1.6ng/ml (G2; P>0,05). The pregnancy rate (PR) was 22.2 (G1) and 60% (G2; P=0,11). In the exp. 2 the buffalo females of G1 (1500IU of hCG; n=21) and G2 (1000IU of hCG; n=21) received 500IU of eCG on D9. On D11, G1 received 1500IU of hCG and G2 1000IU of hCG. The MDDF was 12.4 ± 2.3 (G1) and 12.2 ± 2.5mm (G2; P>0,05), the DOF was 12.6 ± 2.3 (G1) and 12.5 ± 2.7mm (G2; P>0,05), DWO was 67.7 ± 18.1 (G1) and 72.8 ± 16.7h (G2; P>0,05), the OR was 67.7 (G1) and 67.7% (G2; P>0,05), the CLA was 24.8 ± 9.2 (G1) and 28.3 ± 17.2mm2 (G2; P>0,05) and the P4 was 2.3 ± 1.4 (G1) and 2.4 ± 1.3ng/ml (G2; P>0,05). The exp. 3 was identical to exp.2, although the animals of G1 (n=83) and G2 (n=91) received the FTAI on D12. The PR was 53.0 (G1) and 53,8% (G2; P>0,05). In exp. 4, the animals of G1 (n=10) received 500IU and G2 (n=11) 400IU of eCG. Both groups received 1000IU of hCG on D11. The MDDF was 13.2 ± 1.4 (G1) and 13.8 ± 1.8mm (G2; P>0,05), the DOF was 13.7 ± 1.1 (G1) and 14.2 ± 1.5mm (G2; P>0,05), the DWO was 71.1 ± 11.7 (G1) and 75.0 ± 5.5h (G2; P>0,05), the OR was 70.0 (G1) and 72.7% (G2; P>0,05), the CLA was 28.4 ± 8.6 (G1) and 31.6 ± 10.3mm2 (G2; P>0,05) and the P4 was 2.7 ± 1.2 (G1) and 3.3 ± 2.9ng/ml (G2; P>0,05). In exp. 5 (G1/n=54; G2/n=51) was done the same protocol in the exp. 4, although the animals received the FTAI on D12. The PR was 42.6 (G1) and 43.1% (G2; P>0,05). Dosage of 400IU of eCG and 1000IU of hCG, associated to IVD for FTAI were enough to induce follicular growing, ovulation and pregnancy in buffalo females during the off breeding season.

O objetivo do presente estudo foi avaliar a viabilidade da refrigeração do sêmen bovino comparada com a criopreservação. Este estudo foi realizado em dois experimentos. No primeiro experimento foram comparados os efeitos in vitro do sêmen refrigerado em três meios diluidores comerciais a 5&deg; C por até 48 horas, e criopreservado em dois meios. Para este experimento foram utilizados ejaculados de 10 touros da raça Nelore. Cada ejaculado foi dividido em três alíquotas, sendo diluídas nos meios Botubov&reg;, Steridyl&reg; e Bovidyl&reg;. Após a diluição o sêmen foi envasado em palhetas e refrigerado nos três diluidores e criopreservado utilizando somente os meios Botubov&reg; e Steridyl&reg;. A refrigeração do sêmen foi realizada a 5&deg; C por até 48 horas em sistema passivo de refrigeração BotuFlex&reg; e a criopreservação realizada em sistema automatizado TK 4.000&reg;. O sêmen foi avaliado nos tempos 0, 24, 36 e 48 horas após a refrigeração e após a descongelação, para cada diluidor. Foram realizadas análises dos padrões de cinética espermática pelo sistema computadorizado de análise espermática (CASA, programa SCA - Sperm Class Analyser), integridade das membranas plasmática e acrossomal, potencial de membrana mitocondrial e estresse oxidativo por sondas fluorescentes, sob microscopia de epifluorescência e morfologia espermática por microspcopia de contraste de interferência diferencial (DIC). Notou-se efeito de tempo de refrigeração para os três diluidores para de 0 para 24h, se mantendo semelhante até 48 h. Os diluiores Botubov&reg; e Steridyl&reg; preservaram as características espermáticas de forma semelhante até 48 horas de refrigeração diferindo apenas na variável de velocidade curvilianear; no entanto, ambos foram superiores ao diluidor Bovidyl&reg;, para as variáveis, motilidade total, motilidade progressiva, células rápidas, velocidade curvilinear, velocidade progressiva, velocidade do trajeto, retilinearidade, integridade da membrana plasmática, alto potencial de mitocondrial e espermatozoides com membranas plasmática e acrossomal íntegras e alto potencial mitocondrial. O segundo experimento foi realizado, baseado nos resultados do primeiro experimento, para avaliar os efeitos da refrigeração e da criopreservação do sêmen sobre a fertilidade in vivo. Foram utilizados ejaculados de três touros das raças Brangus, Braford e Angus, com idade entre 5 e 7 anos. O sêmen foi colhido por meio de vagina artificial, o ejaculado foi dividido em três alíquotas, sendo duas alíquotas para refrigeração e uma para criopreservação. Para a refrigeração o sêmen foi diluído nas concentrações de 15x106 (R15) e 30x106 (R30) espermatozoides/palheta e para a criopreservação diluído na concentração de 30x106 espermatozoides/palheta (CRIO). Para todas as diluições foi utilizado o meio Botubov&reg; e o sêmen armazenado em palhetas de 0,5 mL. A refrigeração foi realizada a temperatura de 5&deg; C por 48 horas em sistema passivo de refrigeração BotuFlex&reg; e a criopreservação em sistema automatizado TK&reg;. Foram sincronizadas 552 vacas da raça Brangus em programas de inseminação artificial em tempo fixo. Os resultados da taxa de prenhez para os grupos de vacas inseminadas foram de 49,4% para R15, 43,38% para R30 e 47,59% para o sêmen criopreservado. Pode-se concluir que a refrigeração do sêmen a 5&deg; C por 48 horas resulta em taxa de prenhez semelhante às obtidas com o sêmen criopreservado, sendo que esses resultados indicam que a refrigeração por até 48 horas pode ser uma opção de uso para IATF. / The objective of the present study was to evaluate the viability of cooling bovine semen compared to cryopreservation. This study was carried out in two experiments. In the first experiment, the in vitro effects of cooled semen were compared in three commercial extenders at 5&deg; C for up to 48 hours, and cryopreserved in two extender. For this experiment were used ejaculates of 10 Nellore bulls. Each ejaculate was divided into three aliquots, being diluted in the Botubov&reg;, Steridyl&reg; and Bovidyl&reg; extenders. After dilution, the semen was cooled into three extenders and cryopreserved using the Botubov&reg; and Steridyl&reg;. Semen refrigeration was performed at 5&deg; C for up to 48 hours in BotuFlex&reg; passive refrigeration system and cryopreservation performed in TK 3.000&reg; automated system. Semen was evaluated at 0, 24, 36 and 48 hours after refrigeration and after thawing, for each diluent. The sperm kinetics of the spermatic kinetics (CASA, SCA - Sperm Class Analyzer), plasma and acrosomal membrane integrity, mitochondrial membrane potential and oxidative stress by fluorescent probes were analyzed under epifluorescence microscopy and sperm morphology By Differential Interference Contrast Microscopy (DIC). The Botubov&reg; and Steridyl&reg; diluents were very similar after 48 hours of cooling differing significantly only in the Curvilianear Velocity (VCL) 106.04 m/s and 124.56 m/s. The Bovidyl&reg; diluent yielded results significantly lower than the 48 hours of refrigeration for the variables: total motility (MT), progressive motility (MPRO), fast cells (RAP), curvilinear velocity (VCL), progressive velocity (AP), plasma membrane integrity (PI), high mitochondrial potential (AP), and spermatozoa with intact plasma and acrosomal membranes and high mitochondrial potential (PIAIA). The second experiment was carried out, based on the results of the first experiment I, to evaluate the effects of cooled and cryopreservation of semen on in vivo fertility. We used ejaculates of three bulls of the Brangus, Braford and Angus breeds of a IA center, aged between 5 and 7 years. The semen was collected by artificial vagina, the ejaculate was divided into three aliquots, two aliquots for refrigeration and one for cryopreservation. For cooling, the semen was diluted in the concentrations of 15x106 (R15) and 30x106 (R30) spermatozoa/straw, for cryopreservation diluted in the concentration of 30x106 spermatozoa / vane (CRIO). For all dilutions, the Botubov&reg; medium and the semen stored in 0.5 mL vial were used. Refrigeration was carried out at a temperature of 5&deg; C for 48 hours in BotuFlex&reg; passive refrigeration system and cryopreservation in an automated TK&reg; system. 552 Brangus cows were synchronized in fixed-time artificial insemination programs. The results of the pregnancy rate for the groups of inseminated cows were 49.4% for R15, 43.38% for R30 and 47.59% for cryopreserved semen. It can be concluded that the cooling of the semen at 5&deg; C for 48 hours results in pregnancy rate similar to those obtained with cryopreserved semen, and these results indicate that refrigeration for up to 48 hours may be an option of use for FTAI.

Em experimento conduzido com o objetivo de avaliar os efeitos da concentração da dose de sêmen e o horário da inseminação artificial a tempo pré-fixado, foram utilizadas 516 fêmeas bovinas. Os animais, das raças Aberdeen Angus (Bos taurus) e Braford (Bos taurus 5/8 x Bos indicus 3/8) eram constituídos de 270 novilhas e 246 vacas multíparas. Os animais foram submetidos a um protocolo de sincronização de estros e ovulação através de implante vaginal contendo 250 mg de Acetato de Medroxiprogesterona (MAP) associado a duas aplicações de Benzoato de Estradiol (BE), sendo a primeira de 2 mg IM por ocasião da inserção do implante e a segunda de 1 mg IM vinte e quatro horas após a retirada do mesmo. Quando da remoção do implante foram administrados 500 mcg de Cloprostenol Sódico. As inseminações foram efetuadas às 48, 54 ou 60 horas após a retirada do implante, utilizando para cada momento duas concentrações distintas de espermatozóides viáveis, 10 e 20 milhões por dose. Verificou-se que as fêmeas (em especial as novilhas) inseminadas às 48 horas com 20 milhões de sptz/dose apresentaram índice de prenhez significativamente maior do que as inseminadas no mesmo momento com 10 milhões sptz/dose. As vacas inseminadas com 10 milhões de sptz às 60h apresentaram melhor taxa de prenhez (p<0,05) quando comparadas às inseminadas com 10 milhões de sptz às 48h. O percentual de prenhez encontrado nas vacas foi significativamente maior que o das novilhas, assim como o verificado nas fêmeas Aberdeen Angus, comparadas às Braford. A taxa de prenhez de novilhas inseminadas a tempo fixo pode ser incrementada utilizando-se maior número de espermatozóides viáveis por dose inseminante. / The objective of this study was to analyse the effects of semen concentration and moment of fixed timed insemination on pregnancy rates in 516 beef cattle females of the Aberdeen Angus (Bos taurus) and Braford (Bos taurus 5/8 x Bos indicus 3/8) breeds. The females were constituted of 270 heifers and 246 multiparous cows. The animals were all submitted to a synchronization program consisting of vaginal implants of 250mg of medroxiprogesterone acetate (MPA) associated to application of 2mg IM of estradiol benzoate (EB).After 7 days the implants were removed and 500 mg of cloprostenol were injected at the time. After 24hs of implant removal 1mg IM of EB was injected. The inseminations were done 48, 54 and 60 hours after the removal of the implants and semen with 10 and 20 million viable spermatozoa per dosis was used. The females (specially the heifers) of the group inseminated 48 hours after implant removal and using semen with 20 million viable sptz showed a significant higher percentage of pregnancy than the inseminated 48 hours using 10 million viable sptz. The cows inseminated at 60 hours with 10 million sptz showed higher pregnancy rates (p<0,05) than cows inseminated at 48 hours with 10 million sptz. The total pregnancy rate achieved on the cows was significantly higher than on the heifers. The females of the A. Angus group had higher pregnancy rates than the females of the Braford breed. The pregnancy rate of heifers fixed-timed inseminated can be increased using a higher semen concentration.

Em experimento conduzido com o objetivo de avaliar os efeitos da concentração da dose de sêmen e o horário da inseminação artificial a tempo pré-fixado, foram utilizadas 516 fêmeas bovinas. Os animais, das raças Aberdeen Angus (Bos taurus) e Braford (Bos taurus 5/8 x Bos indicus 3/8) eram constituídos de 270 novilhas e 246 vacas multíparas. Os animais foram submetidos a um protocolo de sincronização de estros e ovulação através de implante vaginal contendo 250 mg de Acetato de Medroxiprogesterona (MAP) associado a duas aplicações de Benzoato de Estradiol (BE), sendo a primeira de 2 mg IM por ocasião da inserção do implante e a segunda de 1 mg IM vinte e quatro horas após a retirada do mesmo. Quando da remoção do implante foram administrados 500 mcg de Cloprostenol Sódico. As inseminações foram efetuadas às 48, 54 ou 60 horas após a retirada do implante, utilizando para cada momento duas concentrações distintas de espermatozóides viáveis, 10 e 20 milhões por dose. Verificou-se que as fêmeas (em especial as novilhas) inseminadas às 48 horas com 20 milhões de sptz/dose apresentaram índice de prenhez significativamente maior do que as inseminadas no mesmo momento com 10 milhões sptz/dose. As vacas inseminadas com 10 milhões de sptz às 60h apresentaram melhor taxa de prenhez (p<0,05) quando comparadas às inseminadas com 10 milhões de sptz às 48h. O percentual de prenhez encontrado nas vacas foi significativamente maior que o das novilhas, assim como o verificado nas fêmeas Aberdeen Angus, comparadas às Braford. A taxa de prenhez de novilhas inseminadas a tempo fixo pode ser incrementada utilizando-se maior número de espermatozóides viáveis por dose inseminante. / The objective of this study was to analyse the effects of semen concentration and moment of fixed timed insemination on pregnancy rates in 516 beef cattle females of the Aberdeen Angus (Bos taurus) and Braford (Bos taurus 5/8 x Bos indicus 3/8) breeds. The females were constituted of 270 heifers and 246 multiparous cows. The animals were all submitted to a synchronization program consisting of vaginal implants of 250mg of medroxiprogesterone acetate (MPA) associated to application of 2mg IM of estradiol benzoate (EB).After 7 days the implants were removed and 500 mg of cloprostenol were injected at the time. After 24hs of implant removal 1mg IM of EB was injected. The inseminations were done 48, 54 and 60 hours after the removal of the implants and semen with 10 and 20 million viable spermatozoa per dosis was used. The females (specially the heifers) of the group inseminated 48 hours after implant removal and using semen with 20 million viable sptz showed a significant higher percentage of pregnancy than the inseminated 48 hours using 10 million viable sptz. The cows inseminated at 60 hours with 10 million sptz showed higher pregnancy rates (p<0,05) than cows inseminated at 48 hours with 10 million sptz. The total pregnancy rate achieved on the cows was significantly higher than on the heifers. The females of the A. Angus group had higher pregnancy rates than the females of the Braford breed. The pregnancy rate of heifers fixed-timed inseminated can be increased using a higher semen concentration.

Em experimento conduzido com o objetivo de avaliar os efeitos da concentração da dose de sêmen e o horário da inseminação artificial a tempo pré-fixado, foram utilizadas 516 fêmeas bovinas. Os animais, das raças Aberdeen Angus (Bos taurus) e Braford (Bos taurus 5/8 x Bos indicus 3/8) eram constituídos de 270 novilhas e 246 vacas multíparas. Os animais foram submetidos a um protocolo de sincronização de estros e ovulação através de implante vaginal contendo 250 mg de Acetato de Medroxiprogesterona (MAP) associado a duas aplicações de Benzoato de Estradiol (BE), sendo a primeira de 2 mg IM por ocasião da inserção do implante e a segunda de 1 mg IM vinte e quatro horas após a retirada do mesmo. Quando da remoção do implante foram administrados 500 mcg de Cloprostenol Sódico. As inseminações foram efetuadas às 48, 54 ou 60 horas após a retirada do implante, utilizando para cada momento duas concentrações distintas de espermatozóides viáveis, 10 e 20 milhões por dose. Verificou-se que as fêmeas (em especial as novilhas) inseminadas às 48 horas com 20 milhões de sptz/dose apresentaram índice de prenhez significativamente maior do que as inseminadas no mesmo momento com 10 milhões sptz/dose. As vacas inseminadas com 10 milhões de sptz às 60h apresentaram melhor taxa de prenhez (p<0,05) quando comparadas às inseminadas com 10 milhões de sptz às 48h. O percentual de prenhez encontrado nas vacas foi significativamente maior que o das novilhas, assim como o verificado nas fêmeas Aberdeen Angus, comparadas às Braford. A taxa de prenhez de novilhas inseminadas a tempo fixo pode ser incrementada utilizando-se maior número de espermatozóides viáveis por dose inseminante. / The objective of this study was to analyse the effects of semen concentration and moment of fixed timed insemination on pregnancy rates in 516 beef cattle females of the Aberdeen Angus (Bos taurus) and Braford (Bos taurus 5/8 x Bos indicus 3/8) breeds. The females were constituted of 270 heifers and 246 multiparous cows. The animals were all submitted to a synchronization program consisting of vaginal implants of 250mg of medroxiprogesterone acetate (MPA) associated to application of 2mg IM of estradiol benzoate (EB).After 7 days the implants were removed and 500 mg of cloprostenol were injected at the time. After 24hs of implant removal 1mg IM of EB was injected. The inseminations were done 48, 54 and 60 hours after the removal of the implants and semen with 10 and 20 million viable spermatozoa per dosis was used. The females (specially the heifers) of the group inseminated 48 hours after implant removal and using semen with 20 million viable sptz showed a significant higher percentage of pregnancy than the inseminated 48 hours using 10 million viable sptz. The cows inseminated at 60 hours with 10 million sptz showed higher pregnancy rates (p<0,05) than cows inseminated at 48 hours with 10 million sptz. The total pregnancy rate achieved on the cows was significantly higher than on the heifers. The females of the A. Angus group had higher pregnancy rates than the females of the Braford breed. The pregnancy rate of heifers fixed-timed inseminated can be increased using a higher semen concentration.

Com o intuito de contribuir para a melhoria da eficiência na reprodução de vacas leiteiras de alta produção, objetivou-se no presente trabalho avaliar a taxa de concepção (TC) e a perda gestacional precoce (PGP) em vacas da raça Holandesa suplementadas com 900 mg de progesterona injetável de longa ação, quatro dias após Inseminação Artificial em Tempo Fixo (IATF) em relação ao grupo controle. A pesquisa foi desenvolvida em rebanho leiteiro comercial na cidade de Descalvado-SP, durante o período de janeiro de 2016 até janeiro de 2017, resultando em um total de 1.414 protocolos de IATF, sendo 708 do grupo experimental com progesterona (G1) e 706 do grupo controle (G2). Não houve diferença na TC aos 30 (p=0,276) e aos 60 dias (p=0,215) de G1 em relação a G2. Houve diferença significativa PGP (p=0,007), em que foi possível aferir que vacas tratadas com progesterona pós-IATF tiveram 2,1 vezes mais chance de perderem a gestação em relação àquelas do grupo controle. Foi realizado teste de regressão logística para os subgrupos que foram ao final significativos para efeito de progesterona: Vacas (G1) com 1-4 inseminações, primíparas, no inverno obtiveram 63% menos chance de se tornarem prenhes aos 30 dias. Vacas com mais de 4 inseminações no verão obtiveram 2,5 vezes mais chance de se tornarem prenhes aos 30 dias e 2,6 vezes mais chance de se tornarem prenhes aos 60 dias. Conclui-se que a utilização indiscriminada de progesterona injetável pós-IATF neste estudo não trouxe melhoria em TC30 e TC60 e houve aumento de PGP. No entanto, pode-se afirmar que a suplementação de progesterona influencia positivamente as TC30 e TC60 para a classe de vacas com mais de 4 inseminações no período do verão. / To improve the reproductive efficiency of high production dairy cows, the aim of the present study was to evaluate the conception rate of Holstein cows of high production supplemented with 900 mg of long acting injectable progesterone, four days after FTAI and Early Pregnancy Loss (EPL) comparing it to the control group. The project is a result of information collected from a commercial dairy herd from Descalvado-SP, during January 2016 until January 2017, totalizing 1414 FTAI protocols, 708 within the experimental group with progesterone supplementation (G1) and 706 within the control group (G2). There was no statistical difference in conception rate at 30 days (CR30) (p = 0.276) and conception rate at 60 days (CR60) (p = 0.215) between G1 and G2. There was a significant difference in the EPL (p = 0.007), which was possible to ascertain that cows treated with progesterone after FTAI were 2.1 times more likely to lose pregnancy than those in the control group. A logistic regression test was performed to evaluate the interaction of classes and those relations to progesterone, within the values of p &lt;0.1 considered for group subdivisions. Among the subgroups that were significant for progesterone effect: Cows that received 1 to 4 inseminations primiparous in the winter, for CR30 (p = 0.009); Cows with 5 or more inseminations in the summer for CR30 (p = 0.004) and CR60 (p = 0.008). Cows with 1-4 inseminations, primiparous, in the winter were 63% less likely to become pregnant at 30 days. Cows with more than 4 inseminations in the summer were 2.5 times more likely to become pregnant at 30 days and 2.6 times more likely to become pregnant at 60 days. It was concluded that the indiscriminate use of injectable progesterone after FTAI in this study did not bring improvement in CR30 neither CR60 and the reproductive efficiency was decreased, with increase of EPL. It is possible to hold true that that progesterone supplementation at 4th day after FTAI positively influences the CR30 and CR60 among the cows within the class with more than 4 inseminations in the summer.