Efficiency and accuracy of different ovulation inducers after progesterone device removal in crossbred multiparous cows / Eficiência e acurácia de diferentes indutores de ovulação após a remoção do dispositivo de progesterona em vacas mestiças multíparas

The aim of this study was to verify the efficiency and ovulation time after the administration of different inducers for synchronization of ovulation in beef cows. One hundred and eight non-lactating cows were distributed into the control group (CG; untreated; n=28), estradiol benzoate (EB) group (EBG; n=28); 17 beta-estradiol (17ßE) group (17ßEG; n=28), and deslorelin (DES) group (DESG; n=24). On day minus 11 (D-11) of the protocol, the CG underwent application of cloprostenol and ultrasound examination (US); on D0, progesterone (P4) was inserted plus EB; on D7, cloprostenol was applied; on D9, P4 was removed and cloprostenol plus 400 IU of equine chorionic gonadotropin (eCG) was injected. The EBG was subjected to treatment identical to that of the CG, except on D10, when the cows received EB. The 17ßE was subjected to the same protocol used in the CG except for the administration of 17ßE on D10. And, the DESG was subjected to the same treatment as the CG, except on D10, when the group received DES acetate. Twelve hours after the administration of EB, 17ßE and DES, ovarian US were performed every 6 hours. The preovulatory follicle (POF) diameters measured before ovulation were 19.5; 14.7; 18.7 and 19.8 mm respectively for CG, EBG, 17ßEG and DESG; and the time intervals between inducer application and ovulation were 20.2; 18.9; 21.0 and 22.5 hours respectively. In conclusion, all ovulation inducers were efficient in promoting ovulation; the inducers caused ovulation between 18.9 and 22.5 hours; EB promoted ovulation in a shorter time (P<0.05); 17ßE and DES showed greater variation in application/ovulation time between groups.

O objetivo do estudo foi verificar a eficiência e a ovulação após a administração de diferentes indutores para a sincronização da ovulação em vacas de corte. Cento e oito vacas não-lactantes foram distribuídas em grupo controle (GC; não tratadas; n=28); grupo benzoato de estradiol (BE) (GBE; n=28); grupo 17 beta-estradiol (17ßE) (G17ßE; n=28) e grupo deslorelina (DES) (GDES; n=24). No dia menos 11 (D-11) do protocolo, o GC recebeu cloprostenol e exame ultrassonográfico (US); ao D0, dispositivo de progesterona (P4) foi inserido mais BE; ao D7, cloprostenol foi aplicado; ao D9, a P4 foi removida e cloprostenol mais 400 UI de gonadotrofina coriônica equina (eCG) foi injetada. O GBE foi submetido a tratamento idêntico ao do GC, exceto ao D10, quando as vacas receberam BE. o G17ßE foi submetido ao mesmo protocolo usado no CG exceto pela administração de 17ßE ao D10. E, o GDES foi submetido ao mesmo tratamento que o CG, exceto ao D10, quando o grupo recebeu o acetato de DES. Doze horas após a administração de BE, 17ßE e DES, US ovarianos foram realizados a cada 6 horas. O diâmetro do folículo pré-ovulatório (FPO) medido antes da ovulação foi de 19,5; 14,7; 18,7 e 19,8 mm respectivamente para GC, GBE, G17ßE e GDES; e o intervalo de tempo entre a aplicação do indutor e ovulação foi 20,2; 18,9; 21;0 e 22,5 horas respectivamente. Em conclusão, todos os indutores da ovulação foram eficientes em promover a ovulação; os indutores acarretaram ovulação entre 18,9 e 22,5 horas; o BE promoveu a ovulação em menor espaço de tempo (P<0,05); 17ßE e DES demonstraram maior variação em aplicação/tempo de ovulação entre os grupos.

Reproductive performance of fixed-time artificial insemination in heifers supplemented with a homeopathic complex / Desempenho reprodutivo à inseminação artificial em tempo fixo em novilhas suplementadas com complexo homeopático

For this study, ½ blood Nelore × Aberdeen Angus heifers (n = 40; 14 months) were divided into two groups: control (n=20; 310 kg) and Pró-Cio (n=20; 304 kg). For Pró-Cio group, 20g of homeopathic product (Pró-cio®, Real H, Campo Grande, Brazil) was supplied together with corn eighteen days prior (D-18) to the beginning of the fixed-time artificial insemination protocol (FTAI). On D0, all females received an intravaginal P4 device and 2 mg BE. On D5, the AFC was assessed by ultrasound and blood was collected for AMH dosage. On D8, P4 device was removed; 300 IU eCG, 0.530 mg of cloprostenol sodium and 0.5 mg of EC were administered; an estrus-identifying adhesive was fixed at the tail insertion and the diameter of the dominant follicle (DF) was measured. On D10, all heifers were inseminated, estrus manifestation was assessed and the preovulatory follicle (POF) was measured. On D20, the CL area was measured and blood flow was assessed using Doppler ultrasound. Data were analyzed by Student, Mann-Whitney or Friedman test. The rates of heat expression, ovulation, and blood flow score with Doppler were analyzed using Fisher's exact test and pregnancy rate by binary logistic regression model (P ≤ 0.05). There was no difference in AFC or AMH dosage (P > 0.05). Pró-Cio group had greater diameters of the DF (9.94 ± 0.42 mm) and POF (11.61 ± 0.56 mm) than the controls (DF: 7.72 ± 0.34 mm and POF: 9.91 ± 0.37 mm), as well a larger CL area (3.26 ± 0.26 versus 2.35 ± 0.16 cm2) and a higher mean CL vascularization score (3.06 versus 2.26; P < 0.05). There was no significant difference (P > 0.05) between estrus manifestation or conception rate for control and Pró-Cio groups. Heifers supplemented with the homeopathic product showed larger follicular diameters at the end of the FTAI protocol and CL with better blood flow scores compared to the control group.

Para esse estudo, novilhas ½ sangue Nelore x Aberdeen Angus (n = 40; 14 meses) foram divididas em dois grupos: Controle (n = 20; 310 kg) e Pró-cio (n = 20; 304 kg). Para o grupo Pró-Cio, 20 g/animal de produto homeopático (Pró-cio®, Real H, Campo Grande, Brazil) foi fornecido juntamente com o milho dezoito dias antes (D-18) de inicar o protocolo de inseminaçãoa artificial em tempo-fixo (IATF). No D0, todas as fêmeas receberam um dispositivo intravaginal de P4 e 2 mg BE. No D5, avaliou-se a contagem de folículos antrais (CFA) por ultrassonografia e realizou-se coleta de sangue para dosagem de AMH. No D8, procedeu-se a retirada do dispositivo de P4; aplicação de 300 UI de eCG, 0,530 mg de cloprostenol sódico e 0,5 mg de CE; um adesivo identificador de estro foi fixado na inserção da cauda e foi feita a mensuração do diâmetro do folículo dominante (FD). No D10, todas as novilhas foram inseminadas, foi realizada a avaliação da manifestação de estro e mensuração do folículo pré-ovulatório (FPO). No D20, realizou-se mensuração da área e avaliação do fluxo sanguíneo do CL por ultrassonografia Doppler. Os dados foram analisados pelos testes de Student, Mann-Whitney ou Friedman. As taxas de expressão de estro, ovulação e escore de fluxo sanguíneo com Doppler foram analisadas usando o teste exato de Fisher e taxa de prenhez pelo modelo de regressão logística binária (p ≤ 0,05). Não houve diferença na CFA nem na dosagem de AMH (p > 0,05). O grupo PróCio apresentou maior diâmetro do FD (9,94 ± 0,42 mm) e FPO (11,61 ± 0,56 mm) em relação ao controle (FD: 7,72 ± 0,34 mm e FPO: 9,91 ± 0,37 mm), além de maior área do CL (3,26 ± 0,26 versus 2,35 ± 0,16 cm2; p < 0,05) e maior escore de vascularização médio do CL (3,06 versus 2,26; p < 0,05). Não houve diferença (p > 0,05) na taxa de manifestação de estro e nem na taxa de concepção entre os grupos Controle e Pró-Cio, respectivamente. Novilhas suplementadas com o produto homeopático apresentaram maiores diâmetros foliculares ao final do protocolo de IATF e CL com melhores escores de fluxo sanguíneo em relação ao grupo controle.

Influence of eCG and reproductive management in the resynchronization of ovulation in dairy goats

Resynchronization protocols have been proposed as a way of shortening females' unproductive time in the flock, with good results in cattle and sheep. In goats, initial studies have shown that a second progestogen device inserted before luteolysis and pregnancy diagnosis does not interfere with the corpus luteum lifespan or functionality. This study aimed to evaluate the follicular growth, ovulation pattern and pregnancy rate after insertion of a second and new progestogen device for resynchronizing, with or without equine Chorionic Gonadotrophin (eCG), submitted to natural mating (NM) or artificial insemination (AI) to propose a viable resynchronization protocol for dairy goats. A total of 38 multiparous Saanen goats underwent a short-term progesterone protocol [six days exposed to medroxyprogesterone acetate (MAP) intravaginal sponges + 200 IU eCG and 0.12 mg of cloprostenol sodium on the 5th day + 0.025 mg of lecirelin 34 hours after sponge withdrawal] and, on day 16th after the ovulation, received a new MAP device which was retained until day 21. At this moment females were split into four groups: GeCG+NM ­ 100 IU eCG with NM; GSal+NM ­ saline solution with NM; GeCG+AI ­ 100 IU eCG with AI; and GSal+AI ­ saline solution with AI. Ultrasound scans were performed every 12 h from sponge withdrawal (day 21) until 108 h after sponge withdrawal (day 25) for follicular dynamics evaluation, at 240 h (day 31) for assessing the presence of active corpus luteum, and on day 60 for pregnancy diagnosis. No differences were found regarding ovulation time, synchronization and follicle size. However, GeCG+NM presented a greater estrus manifestation rate (100%) and pregnancy rate (62.5%) when compared to GSal+AI. In conclusion, resynchronization protocols in dairy goats may present satisfactory results.(AU)

Níveis de progesterona e os parâmetros reprodutivos no período periovulatório de vacas Nelore submetidas ao protocolo de IATF / Progesterone levels and reproductive parameters in the periovulatory period of Nellore cows under FTAI protocol

Background: Fixed Time Artificial Insemination (FTAI) has achieved a significant evolution in the last 18 years, however, despite the progress achieved by modern FTAI programs, the conception rates obtained are still low. Therefore, this study aimed to evaluate the interrelation between progesterone levels in the periovulatory period and reproductive parameters of Nellore cows submitted to an FTAI protocol. Materials, Methods & Results: On a random day, called day 0 (D0), 57 cows received a P4 device associated with the intramuscular (IM) application of 2.0 mg of estradiol benzoate. On D9, the P4 devices were removed and then were administered 500 µg of cloprostenol sodium IM; 0.6 mg of estradiol cypionate IM and 300 IUI of Equine Chorionic Gonadotrophin IM. Blood samples were collected for the determination of serum P4 concentrations on D9 and D11 of the protocol. The evaluations of follicular diameter (DFOL), follicular wall area (AFOL) and the vascularization area of the follicle wall (VFOL) were carried out on D11 using B-mode ultrasonography examination and colour Doppler, and then the artificial inseminations were performed. The evaluation of the corpus luteum diameter (CLD), of the total corpus luteum area (CLA), of the area of corpus luteum vascularization (CLV) and blood sampling for determination of postovulatory P4 levels (Post-P4) were performed on D24. For the analysis of the P4 concentration the chemiluminescence method was used, with a sensitivity of 0.1 ng/mL. According to the P4 concentrations on D11, cows were divided into 2 groups, LOW LEVELS OF P4 and HIGH LEVELS OF P4. The diagnosis of pregnancy was performed using transrectal ultrasonography on D45, at this point the cows were divided into 2 groups, PREGNANT and NON-PREGNANT. The correlation between DFOL and P4 dosage on D11 was moderate, negative and significant and between the AFOL and the serum P4 levels on D9, was moderate, negative and significant. As for the other correlations between follicular and luteal parameters and serum P4 levels, these were low to moderate, negative and not significant. Cows in the LOW LEVELS OF P4 group had significantly larger diameter and follicular areas than the cows in the HIGH LEVELS OF P4 group, the other follicular and luteal parameters showed no statistical difference. Of the total 57 cows that were inseminated, 30 cows became pregnant. Cows in the PREGNANT group had serum P4 levels on D9 equivalent to that obtained by the NON-PREGNANT group. However, at D11 the cows that became pregnant presented significantly lower serum P4 levels than cows that did not become pregnant. Discussion: The results of the interrelation between follicular parameters and P4 levels obtained in the present study, pointed out that the lower the levels of P4, the higher the follicular parameters, corroborating with other authors. Thus, larger preovulatory follicles provided high ovulation rates. Periovulatory serum P4 levels did not significantly affect the morphofunctional parameters of the CL. Such findings may be justified by high periovulatory P4 levels resulting from less efficient luteolysis, exert a negative effect on the results of FTAI protocols, because progesterone inhibits the release of LH pulses. It is concluded that lower periovulatory P4 levels established a favourable condition for follicular development and fertility, however, morphofunctional parameters of the corpus luteum were not affected.

Prostaglandin F2α as ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome / Prostaglandina F2α como estímulo ovulatório em vacas e búfalas leiteiras criadas no bioma Amazônia

This study evaluated the effect of a prostaglandin F2? (PGF) analogue as an ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome. To this end, three experiments were performed in the state of Rondônia, located in the Amazon biome. In Experiment 1, 22 lactating dairy buffaloes received 2 mg of intramuscular (I.M.) estradiol benzoate (EB) on day 0 and an intravaginal progesterone-releasing device (CIDR) from day 0 to day 9 of the protocol. On days 8 and 9, all cows were given 500 ?g of I.M. d-cloprostenol (PGF analogue). On day 10, buffaloes were divided into two groups to receive 500 ?g of PGF (PGF group, n = 8) or no treatment (CTL group, n = 14), respectively. In Experiment 2, 16 lactating crossbred dairy cows (Holstein x Gir) received 2 mg of EB on day 0 and a CIDR insert from day 0 to day 8. On days 7 and 8, all cows were given 500 ?g of d-cloprostenol. On day 9, cows were divided into two groups to receive 500 ?g of d-cloprostenol (PGF group, n = 8) or no treatment (CTL group, n = 8), respectively. In Experiment 3, 16 lactating crossbred dairy cows (Holstein x Gir) were handled and treated similarly as in Experiment 2, although cows did not receive d-cloprostenol on day 8. Single-point outcome variables were analyzed using one-way analysis of variance (ANOVA), while proportions with dichotomous outcomes were analyzed with the chi-square test.(AU)

O objetivo deste estudo foi avaliar o efeito de um análogo de prostaglandina F2α (PGF) como indutor ovulatório em vacas leiteiras e búfalas. Para este fim, três experimentos foram realizados no estado de Rondônia, localizado no bioma Amazônia. No Experimento 1, 22 búfalas leiteiras em lactação receberam 2 mg de benzoato de estradiol (EB) im, no Dia 0 e um dispositivo intravaginal de liberação de progesterona (CIDR) do Dia 0 ao Dia 9 do protocolo. Nos Dias 8 e 9, todas as vacas receberam 150μg de d-Cloprostenol (análogo PGF), im. No Dia 10, as búfalas foram divididas em dois grupos para receber 150μg de PGF (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 14). No experimento 2, 16 vacas leiteiras mestiças (Holandês x Gir) receberam 2 mg de EB no Dia 0 e um dispositivo intravaginal (CIDR) do Dia 0 ao Dia 8. Nos Dias 7 e 8 todas as vacas receberam 150μg de d-Cloprostenol. No Dia 9, as vacas foram divididas em dois grupos para receber 150μg de d-Cloprostenol (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 8). No Experimento 3, 16 vacas leiteiras mestiças (Holandês x Gir) foram tratadas da mesma forma que no Experimento 2, porém, as vacas não receberam d-Cloprostenol no Dia 8. Variáveis quantitativas foram analisados por análise de variância - one-way ANOVA e variáveis dicotômicas foram analisados pelo teste do qui-quadrado. No Experimento 1, não houve diferença (P = 0,30) na taxa de ovulação entre os grupos, em média 68% das búfalas ovularam após o tratamento. Além disso, não houve diferença entre os grupos no intervalo de ovulação (P = 0,61) e no diâmetro do folículo pré-ovulatório (P = 0,47). No Experimento 2, apenas uma vaca do Grupo PG não ovulou. Não houve diferenças no intervalo de ovulação entre os grupos CTL e PG (P = 0,69). Em média, a ovulação ocorreu 82 horas após a remoção do CIDR. No Experimento 3, vacas tratadas com PGF ovularam antes do Grupo CTL (62,5 ± 5,8 vs 94,5 ± 13,5 h; P = 0,05). Coletivamente, esses resultados sugeriram que a PGF antecipa a ovulação em vacas leiteiras em lactação, porém seu efeito não foi observado em búfalas.(AU)

Prostaglandin F2α as ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome / Prostaglandina F2α como estímulo ovulatório em vacas e búfalas leiteiras criadas no bioma Amazônia

This study evaluated the effect of a prostaglandin F2? (PGF) analogue as an ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome. To this end, three experiments were performed in the state of Rondônia, located in the Amazon biome. In Experiment 1, 22 lactating dairy buffaloes received 2 mg of intramuscular (I.M.) estradiol benzoate (EB) on day 0 and an intravaginal progesterone-releasing device (CIDR) from day 0 to day 9 of the protocol. On days 8 and 9, all cows were given 500 ?g of I.M. d-cloprostenol (PGF analogue). On day 10, buffaloes were divided into two groups to receive 500 ?g of PGF (PGF group, n = 8) or no treatment (CTL group, n = 14), respectively. In Experiment 2, 16 lactating crossbred dairy cows (Holstein x Gir) received 2 mg of EB on day 0 and a CIDR insert from day 0 to day 8. On days 7 and 8, all cows were given 500 ?g of d-cloprostenol. On day 9, cows were divided into two groups to receive 500 ?g of d-cloprostenol (PGF group, n = 8) or no treatment (CTL group, n = 8), respectively. In Experiment 3, 16 lactating crossbred dairy cows (Holstein x Gir) were handled and treated similarly as in Experiment 2, although cows did not receive d-cloprostenol on day 8. Single-point outcome variables were analyzed using one-way analysis of variance (ANOVA), while proportions with dichotomous outcomes were analyzed with the chi-square test.

O objetivo deste estudo foi avaliar o efeito de um análogo de prostaglandina F2α (PGF) como indutor ovulatório em vacas leiteiras e búfalas. Para este fim, três experimentos foram realizados no estado de Rondônia, localizado no bioma Amazônia. No Experimento 1, 22 búfalas leiteiras em lactação receberam 2 mg de benzoato de estradiol (EB) im, no Dia 0 e um dispositivo intravaginal de liberação de progesterona (CIDR) do Dia 0 ao Dia 9 do protocolo. Nos Dias 8 e 9, todas as vacas receberam 150μg de d-Cloprostenol (análogo PGF), im. No Dia 10, as búfalas foram divididas em dois grupos para receber 150μg de PGF (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 14). No experimento 2, 16 vacas leiteiras mestiças (Holandês x Gir) receberam 2 mg de EB no Dia 0 e um dispositivo intravaginal (CIDR) do Dia 0 ao Dia 8. Nos Dias 7 e 8 todas as vacas receberam 150μg de d-Cloprostenol. No Dia 9, as vacas foram divididas em dois grupos para receber 150μg de d-Cloprostenol (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 8). No Experimento 3, 16 vacas leiteiras mestiças (Holandês x Gir) foram tratadas da mesma forma que no Experimento 2, porém, as vacas não receberam d-Cloprostenol no Dia 8. Variáveis quantitativas foram analisados por análise de variância - one-way ANOVA e variáveis dicotômicas foram analisados pelo teste do qui-quadrado. No Experimento 1, não houve diferença (P = 0,30) na taxa de ovulação entre os grupos, em média 68% das búfalas ovularam após o tratamento. Além disso, não houve diferença entre os grupos no intervalo de ovulação (P = 0,61) e no diâmetro do folículo pré-ovulatório (P = 0,47). No Experimento 2, apenas uma vaca do Grupo PG não ovulou. Não houve diferenças no intervalo de ovulação entre os grupos CTL e PG (P = 0,69). Em média, a ovulação ocorreu 82 horas após a remoção do CIDR. No Experimento 3, vacas tratadas com PGF ovularam antes do Grupo CTL (62,5 ± 5,8 vs 94,5 ± 13,5 h; P = 0,05). Coletivamente, esses resultados sugeriram que a PGF antecipa a ovulação em vacas leiteiras em lactação, porém seu efeito não foi observado em búfalas.

Técnica de inseminação artificial por tração cervical e função luteal em ovelhas Santa Inês após estro sincronizado com cloprostenol ou progestágeno-eCG / Technique of artificial ins emination by cervical traction and luteal function in Santa Inês ewes after synchronized estrus with cloprostenol or progestagen-eCG

Avaliou-se a influência do protocolo de sincronização de estro na execução da técnica de inseminação artificial por tração cervical (ITC) e subsequente perfil sérico de progesterona em ovelhas Santa Inês. Um grupo foi submetido a duas aplicações de cloprostenol com sete dias de intervalo (PGF2α, n=43), outro grupo foi sincronizado com MAP-eCG (P4-eCG, n=40) e ovelhas ao estro natural (EN, n=10) formaram grupo controle. Com as ovelhas contidas em estação, foi realizada a técnica ITC utilizando um aplicador metálico e mandril. Foram avaliadas a profundidade de penetração e intensidade de reação da ovelha ao manejo da técnica. Dosagens de estradiol e progesterona foram feitas antes e depois da ITC/estro natural, respectivamente. Os níveis de estradiol foram superiores com P4-eCG vs PGF2α (P < 0,05), mas não houve influência do protocolo na execução da técnica. Ocorreram 83,5% de deposição intrauterina do sêmen, o tempo médio foi de 32 segundos e 90,7% das ovelhas apresentaram reação fraca ou moderada durante o manejo. Os níveis de progesterona foram semelhantes entre ITC e estro natural. Independente do protocolo hormonal, a técnica ITC em ovelhas Santa Inês mantidas em estação mostrou-se viável no tempo de penetração da cérvice e deposição intrauterina do sêmen, não comprometendo a função luteal subsequente.(AU)

The influence of estrus synchronization protocol was evaluated on the artificial insemination technique by cervical traction (ICT) and subsequent progesterone serum profile in Santa Inês ewes. One group was submitted to two applications of cloprostenol seven days apart (PGF2α, n=43), another group was synchronized with MAP-eCG (P4-eCG, n=40) and ewes at natural estrus (NE, n=10) formed a control group. With the ewe contained in the stand position, the ICT technique was performed using a metal applicator and mandrel. Depth of penetration and reaction intensity of the ewe to the handling of the technique were evaluated. Dosages of estradiol and progesterone were performed before and after ICT / natural estrus, respectively. Estradiol levels were higher with P4-eCG vs PGF2α(AU)

Técnica de inseminação artificial por tração cervical e função luteal em ovelhas Santa Inês após estro sincronizado com cloprostenol ou progestágeno-eCG / Technique of artificial ins emination by cervical traction and luteal function in Santa Inês ewes after synchronized estrus with cloprostenol or progestagen-eCG

Avaliou-se a influência do protocolo de sincronização de estro na execução da técnica de inseminação artificial por tração cervical (ITC) e subsequente perfil sérico de progesterona em ovelhas Santa Inês. Um grupo foi submetido a duas aplicações de cloprostenol com sete dias de intervalo (PGF2α, n=43), outro grupo foi sincronizado com MAP-eCG (P4-eCG, n=40) e ovelhas ao estro natural (EN, n=10) formaram grupo controle. Com as ovelhas contidas em estação, foi realizada a técnica ITC utilizando um aplicador metálico e mandril. Foram avaliadas a profundidade de penetração e intensidade de reação da ovelha ao manejo da técnica. Dosagens de estradiol e progesterona foram feitas antes e depois da ITC/estro natural, respectivamente. Os níveis de estradiol foram superiores com P4-eCG vs PGF2α (P < 0,05), mas não houve influência do protocolo na execução da técnica. Ocorreram 83,5% de deposição intrauterina do sêmen, o tempo médio foi de 32 segundos e 90,7% das ovelhas apresentaram reação fraca ou moderada durante o manejo. Os níveis de progesterona foram semelhantes entre ITC e estro natural. Independente do protocolo hormonal, a técnica ITC em ovelhas Santa Inês mantidas em estação mostrou-se viável no tempo de penetração da cérvice e deposição intrauterina do sêmen, não comprometendo a função luteal subsequente.

The influence of estrus synchronization protocol was evaluated on the artificial insemination technique by cervical traction (ICT) and subsequent progesterone serum profile in Santa Inês ewes. One group was submitted to two applications of cloprostenol seven days apart (PGF2α, n=43), another group was synchronized with MAP-eCG (P4-eCG, n=40) and ewes at natural estrus (NE, n=10) formed a control group. With the ewe contained in the stand position, the ICT technique was performed using a metal applicator and mandrel. Depth of penetration and reaction intensity of the ewe to the handling of the technique were evaluated. Dosages of estradiol and progesterone were performed before and after ICT / natural estrus, respectively. Estradiol levels were higher with P4-eCG vs PGF2α

The role of prostaglandin F2α on ovulation and LH release in cows / A função da prostaglandina F2α na ovulação e na liberação de LH em vacas

This study aimed to evaluate the role of prostaglandin F2α (PGF) on ovulation. In Experiment 1, cows were randomly allocated to two treatments to receive 150 µg of d-Cloprostenol (PGF Group, n = 12) or 2 mL of NaCl 0.9% (Control Group, n = 11) and CIDRs, were removed 4 days later. No cow ovulated in Control and PGF groups. In Experiment 2, cows were randomly separated into two experimental groups to receive 4 injections of 150 µg of d-Cloprostenol (n = 9) or 2 mL of NaCL 0.9% (n = 9). In this experiment, ovulation was not observed in any cows. In Experiment 3, ovariectomized cows receive three injections of 300µg of PGF analog (PGF Group, n = 5), 100µg of Lecirelin (GnRH Group, n = 5) or 2 mL of PBS (Control Group, n = 4). The LH concentration was higher (P <0.0001) in cows from the GnRH group than in the PGF and Control groups. In experiment 4, cows with preovulatory follicles (>11.5 mm) were treated with Saline (Control Group, n = 6); Lecirelin (GnRH Group, n = 7) or Cloprostenol Sodium (PGF Group, n = 6). There was a significant increase in the vascular area of follicles from 0 to 24 h in GnRH and PGF treatments. In conclusion, PGF was not able to induce ovulation in cows with high or low plasma progesterone concentration. Additionally, PGF alone was not able to induce LH release and follicle luteinization, but increased follicular vascularization.(AU)

O objetivo deste estudo foi avaliar o papel da prostaglandina F2α (PGF) na ovulação. No Experimento 1, as vacas foram alocadas aleatoriamente em dois tratamentos para receber 150 µg de d-Cloprostenol (Grupo PGF, n = 12) ou 2 mL de NaCl 0,9% (Grupo Controle, n = 11) e os CIDR, foram removidos 4 dias depois. Nenhuma vaca ovulou nos grupos Controle e PGF. No Experimento 2, as vacas foram separadas aleatoriamente em dois grupos experimentais para receber 4 injeções de 150 µg de d-Cloprostenol (n = 9) ou 2 mL de NaCL 0,9% (n = 9). Não foi observada ovulação em nenhum dos animais deste experimento. No Experimento 3, vacas ovariectomizadas receberam três injeções de 300µg de análogo de PGF (Grupo PGF, n = 5), 100µg de Lecirelina (Grupo GnRH, n = 5) ou 2 mL de PBS (Grupo Controle, n = 4). A concentração de LH foi maior (P <0,0001) nas vacas do grupo GnRH do que nos grupos PGF e Controle. No Experimento 4, vacas com folículos pré-ovulatórios (> 11,5 mm) foram tratadas com solução salina (Grupo Controle, n = 6), Lecirelina (Grupo GnRH, n = 7) ou Cloprostenol Sódico (Grupo PGF, n = 6). Houve um aumento significativo na área vascular dos folículos de 0 a 24h nos tratamentos com GnRH e PGF. Em conclusão, a PGF não foi capaz de induzir ovulação em vacas com alta ou baixa concentração plasmática de progesterona. Além disso, a PGF sozinha não foi capaz de induzir a liberação de LH e a luteinização do folículo, mas aumentou a vascularização folicular.(AU)

The role of prostaglandin F2α on ovulation and LH release in cows / A função da prostaglandina F2α na ovulação e na liberação de LH em vacas

This study aimed to evaluate the role of prostaglandin F2α (PGF) on ovulation. In Experiment 1, cows were randomly allocated to two treatments to receive 150 µg of d-Cloprostenol (PGF Group, n = 12) or 2 mL of NaCl 0.9% (Control Group, n = 11) and CIDRs, were removed 4 days later. No cow ovulated in Control and PGF groups. In Experiment 2, cows were randomly separated into two experimental groups to receive 4 injections of 150 µg of d-Cloprostenol (n = 9) or 2 mL of NaCL 0.9% (n = 9). In this experiment, ovulation was not observed in any cows. In Experiment 3, ovariectomized cows receive three injections of 300µg of PGF analog (PGF Group, n = 5), 100µg of Lecirelin (GnRH Group, n = 5) or 2 mL of PBS (Control Group, n = 4). The LH concentration was higher (P <0.0001) in cows from the GnRH group than in the PGF and Control groups. In experiment 4, cows with preovulatory follicles (>11.5 mm) were treated with Saline (Control Group, n = 6); Lecirelin (GnRH Group, n = 7) or Cloprostenol Sodium (PGF Group, n = 6). There was a significant increase in the vascular area of follicles from 0 to 24 h in GnRH and PGF treatments. In conclusion, PGF was not able to induce ovulation in cows with high or low plasma progesterone concentration. Additionally, PGF alone was not able to induce LH release and follicle luteinization, but increased follicular vascularization.(AU)

O objetivo deste estudo foi avaliar o papel da prostaglandina F2α (PGF) na ovulação. No Experimento 1, as vacas foram alocadas aleatoriamente em dois tratamentos para receber 150 µg de d-Cloprostenol (Grupo PGF, n = 12) ou 2 mL de NaCl 0,9% (Grupo Controle, n = 11) e os CIDR, foram removidos 4 dias depois. Nenhuma vaca ovulou nos grupos Controle e PGF. No Experimento 2, as vacas foram separadas aleatoriamente em dois grupos experimentais para receber 4 injeções de 150 µg de d-Cloprostenol (n = 9) ou 2 mL de NaCL 0,9% (n = 9). Não foi observada ovulação em nenhum dos animais deste experimento. No Experimento 3, vacas ovariectomizadas receberam três injeções de 300µg de análogo de PGF (Grupo PGF, n = 5), 100µg de Lecirelina (Grupo GnRH, n = 5) ou 2 mL de PBS (Grupo Controle, n = 4). A concentração de LH foi maior (P <0,0001) nas vacas do grupo GnRH do que nos grupos PGF e Controle. No Experimento 4, vacas com folículos pré-ovulatórios (> 11,5 mm) foram tratadas com solução salina (Grupo Controle, n = 6), Lecirelina (Grupo GnRH, n = 7) ou Cloprostenol Sódico (Grupo PGF, n = 6). Houve um aumento significativo na área vascular dos folículos de 0 a 24h nos tratamentos com GnRH e PGF. Em conclusão, a PGF não foi capaz de induzir ovulação em vacas com alta ou baixa concentração plasmática de progesterona. Além disso, a PGF sozinha não foi capaz de induzir a liberação de LH e a luteinização do folículo, mas aumentou a vascularização folicular.(AU)

Efeito da expressão do estro sobre características morfofuncionais foliculares, luteais e fertilidade em fêmeas Bos indicus sincronizadas para IATF / Effect of the estrus expression on follicular and luteal morphofunctional characteristics and fertility in Bos indicus females synchronized for FTAI

Background: Recent studies have been conducted with the aim of improving the fertility rates in the FTAI programsin beef females. The observation of the estrus expression constitutes an important indicator of fertility in zebu females.Therefore, this work has as an objective to evaluate the impact of the estrus expression on the follicular, luteal and fertilitymorphofunctional characteristics of Nelore females synchronized for FTAI.Materials, Methods & Results: Sixty five lactating female Nelore (Bos taurus indicus) were used. On a random day, denominatedday 0 (D0), the 65 Nelore females received a progesterone-releasing device associated to the application of 2.0 mg of estradiolbenzoate intramuscularly (IM). On D9, the progesterone-releasing intravaginal devices were removed and was administered500 μg of cloprostenol sodium IM; 0.6 mg of estradiol cypionate IM and 300 UI of Equine Chorionic Gonadotropin IM. At thispoint, the animals were marked with a marking stick for the determination of the estrus expression. On D11 of the synchronization protocol, the animals were characterized in two groups: without estrus expression WITHOUT ESTRUS and with estrusexpression WITH ESTRUS. The evaluation of the follicle diameter (FOLD), of the follicle wall area (FOLA), of the folliclewall vascularization (FOLV) and the percentage of vascularization in the area of the preovulatory follicle wall (%FOLV) wereconducted on D11 using B-mode ultrasonography and color Doppler and then the artificial inseminations were performed. Theevaluation of the corpus luteum diameter (CLD), the total area of the corpus luteum (CLA), of the area of vascularization of thecorpus luteum (CLV), of the percentage of vascularization of the in the area of the corpus luteum (% CLV) and the collectionof blood for the evaluation of the serum...

Efeito da expressão do estro sobre características morfofuncionais foliculares, luteais e fertilidade em fêmeas Bos indicus sincronizadas para IATF / Effect of the estrus expression on follicular and luteal morphofunctional characteristics and fertility in Bos indicus females synchronized for FTAI

Background: Recent studies have been conducted with the aim of improving the fertility rates in the FTAI programsin beef females. The observation of the estrus expression constitutes an important indicator of fertility in zebu females.Therefore, this work has as an objective to evaluate the impact of the estrus expression on the follicular, luteal and fertilitymorphofunctional characteristics of Nelore females synchronized for FTAI.Materials, Methods & Results: Sixty five lactating female Nelore (Bos taurus indicus) were used. On a random day, denominatedday 0 (D0), the 65 Nelore females received a progesterone-releasing device associated to the application of 2.0 mg of estradiolbenzoate intramuscularly (IM). On D9, the progesterone-releasing intravaginal devices were removed and was administered500 μg of cloprostenol sodium IM; 0.6 mg of estradiol cypionate IM and 300 UI of Equine Chorionic Gonadotropin IM. At thispoint, the animals were marked with a marking stick for the determination of the estrus expression. On D11 of the synchronization protocol, the animals were characterized in two groups: without estrus expression WITHOUT ESTRUS and with estrusexpression WITH ESTRUS. The evaluation of the follicle diameter (FOLD), of the follicle wall area (FOLA), of the folliclewall vascularization (FOLV) and the percentage of vascularization in the area of the preovulatory follicle wall (%FOLV) wereconducted on D11 using B-mode ultrasonography and color Doppler and then the artificial inseminations were performed. Theevaluation of the corpus luteum diameter (CLD), the total area of the corpus luteum (CLA), of the area of vascularization of thecorpus luteum (CLV), of the percentage of vascularization of the in the area of the corpus luteum (% CLV) and the collectionof blood for the evaluation of the serum...(AU)

Comparison of three doses of estradiol benzoate for synchronization of follicular wave emergence in suckled Bos indicus beef cows

We aimed to compare the effect of three estradiol benzoate (EB) doses on follicular wave emergence (FWE) and dominant follicle growth of suckled Nelore cows submitted to TAI (D0). On a random day of estrous cycle (D−10), multiparous (MULT; n=36) and primiparous (PRIM; n=20) suckled Nelore cows received an intravaginal progesterone (P4) device and were assigned in three groups. Cows in the EB-1 (n=20), EB-1.5 (n=15) or EB-2 (n=21) groups received, respectively, an im treatment with 1, 1.5 or 2 mg EB. A subgroup (n=10-13 cows/group) were subject to daily ovarian evaluations from D−10 to D0. On D−2, P4 devices were removed, and all cows received the same treatment: 1 mg estradiol cypionate, 0.53 mg sodium cloprostenol, and 300 IU eCG. Statistical analyses were performed considering only the main effects of treatment group and parity order. The proportion of cows with a synchronized FWE and the moment of the FWE did not differ (p>0.05) among the treatment groups (overall: 80% [28/35] and 4.1 ± 0.4 days); however, the FWE occurred earlier (p=0.007) in MULT (3.8 ± 0.2 days) than PRIM (5.1 ± 0.4) cows. The proportion of animals detected in estrus was greater (86% [31/36] vs. 70% [14/20]; p=0.02) and the dominant follicle was larger on D−2 (9.7 ± 0.3 mm vs. 7.8 ± 0.7 mm; p=0.006) and D0 (11.9 ± 0.4 mm vs. 10 ± 0.5 mm; p=0.008) in MULT than PRIM cows. In conclusion, the three EB doses presented similar efficiency to synchronize the FWE in suckled Nelore cows. Moreover, a delayed FWE and smaller dominant follicle is observed in PRIM cows, contributing to the reduced reproductive performance in this parity category when using similar TAI protocols of MULT cows.

Comparison of three doses of estradiol benzoate for synchronization of follicular wave emergence in suckled Bos indicus beef cows

We aimed to compare the effect of three estradiol benzoate (EB) doses on follicular wave emergence (FWE) and dominant follicle growth of suckled Nelore cows submitted to TAI (D0). On a random day of estrous cycle (D−10), multiparous (MULT; n=36) and primiparous (PRIM; n=20) suckled Nelore cows received an intravaginal progesterone (P4) device and were assigned in three groups. Cows in the EB-1 (n=20), EB-1.5 (n=15) or EB-2 (n=21) groups received, respectively, an im treatment with 1, 1.5 or 2 mg EB. A subgroup (n=10-13 cows/group) were subject to daily ovarian evaluations from D−10 to D0. On D−2, P4 devices were removed, and all cows received the same treatment: 1 mg estradiol cypionate, 0.53 mg sodium cloprostenol, and 300 IU eCG. Statistical analyses were performed considering only the main effects of treatment group and parity order. The proportion of cows with a synchronized FWE and the moment of the FWE did not differ (p>0.05) among the treatment groups (overall: 80% [28/35] and 4.1 ± 0.4 days); however, the FWE occurred earlier (p=0.007) in MULT (3.8 ± 0.2 days) than PRIM (5.1 ± 0.4) cows. The proportion of animals detected in estrus was greater (86% [31/36] vs. 70% [14/20]; p=0.02) and the dominant follicle was larger on D−2 (9.7 ± 0.3 mm vs. 7.8 ± 0.7 mm; p=0.006) and D0 (11.9 ± 0.4 mm vs. 10 ± 0.5 mm; p=0.008) in MULT than PRIM cows. In conclusion, the three EB doses presented similar efficiency to synchronize the FWE in suckled Nelore cows. Moreover, a delayed FWE and smaller dominant follicle is observed in PRIM cows, contributing to the reduced reproductive performance in this parity category when using similar TAI protocols of MULT cows.(AU)

Different times to perform timed artificial insemination when using a P4/E2/eCG-based protocol in buffalo / Momentos diferentes para executar a inseminação artificial em tempo fixo utilizando o protocolo à base de P4/E2/eCG em búfalas

The aim of this study was to evaluate different times for timed artificial insemination (TAI) in buffalo submitted to a P4/E2/eCG-based protocol. In this study, 204 buffaloes were distributed into one of two groups (TAI56, n=103 and TAI64, n=101). At a random stage of the oestrous cycle (Day 0 = D0), in the morning (TAI56, a.m.) or afternoon (TAI64, p.m.), buffaloes received an intravaginal progesterone device (P4; 1.0 g) plus EB (2.0 mg i.m.). On D9 a.m. (TAI56) or p.m. (TAI64), the P4 was removed and buffaloes received PGF2a (0.53 mg i.m. sodium cloprostenol) and eCG (400 IU i.m.). On D10 a.m. (TAI56) or p.m. (TAI64), 24 h after P4 removal, buffaloes were treated with EB (1.0 mg i.m.). Buffaloes from TAI56 and TAI64 were inseminated 56 and 64 h after P4 removal (D11, p.m. and D12, a.m., respectively). Ultrasound examinations were performed on D0 to ascertain ovarian follicular status, at TAI to measure the diameter of the dominant follicle (DF) and D42 for pregnancy diagnosis. The statistical analysis was performed using the GLIMMIX procedure of SAS®. There was no difference between TAI56 and TAI64 for the diameter of the DF at TAI and the pregnancy per TAI. It was concluded that TAI 56 or 64 h after P4 removal did not affect fertility in buffaloes submitted to the induction of ovulation with EB. The present research supports that is possible to perform TAI at any time throughout the day in buffalo synchronized during the non-breeding season.(AU)

O objetivo deste estudo foi avaliar diferentes momentos para a realização da IATF em búfalas submetidas a um protocolo à base de P4/E2/eCG. Neste estudo, 204 búfalas foram distribuídas em um de dois grupos (IATF56, n=103 e IATF64, n=101). Em estágio aleatório do ciclo estral (Dia 0 = D0), pela manhã (IATF56, manhã) ou pela tarde (IATF64, tarde), as búfalas receberam um dispositivo intravaginal de progesterona (P4; 1,0 g) e BE (2,0 mg i.m.). No D9 pela manhã (IATF56) ou pela tarde (IATF64), a P4 foi removida e as búfalas receberam PGF2a (0,53 mg i.m. cloprostenol sódico) e eCG (400 UI i.m.). No D10 pela manhã (IATF56) ou pela tarde (IATF64), 24 h após a remoção da P4, as búfalas foram tratadas com BE (1,0 mg i.m.). As búfalas dos grupos IATF56 e IATF64 foram inseminadas 56 e 64 h após a remoção da P4 (D11, pela tarde e D12, pela manhã, respectivamente). Avaliações ultrassonográficas foram realizadas no D0 para verificar o status folicular ovariano, na IATF para medir o diâmetro do folículo dominante (FD) e no D42 para o diagnóstico de gestação. A análise estatística foi realizada utilizando o procedimento GLIMMIX do SAS®. Não houve diferença entre os grupos IATF56 e IATF64 no diâmetro do FD na IATF e na prenhez por IATF. Conclui-se que a IATF 56 ou 64 h após a remoção da P4 não afeta a fertilidade de búfalas submetidas à indução da ovulação com BE. A presente pesquisa evidencia que é possível realizar a IATF durante todo o dia em búfalas sincronizadas durante a estação reprodutiva desfavorável.(AU)

Factors associated with pregnancy rate in fixed-time embryo transfer in cattle under humid-tropical conditions of México

The objective was to determine the effect of some factors on pregnancy rate of fixed-time embryo transfer (FTET), in cows and heifers kept under Mexican tropical conditions. Recipients females (n=405) grazing in pastures were selected according to breed group (Zebu and crosses), parity (nulliparous and multiparous), body condition score (BCS) and the presence of a corpus luteum (CL). The females were synchronized on day 0 using a progesterone vaginal device and 2 mg estradiol benzoate (EB), two groups were established. Group 1 (conventional protocol) were animals in which the progesterone device was removed on day 7. At this time, also received an injection of 50 mg cloprostenol sodium and 1 mg estradiol cypionate. Animals also received 300 IU (heifers) or 360 IU (cows) of eCG. Group 2 (J-Synch protocol) were animals in which the progesterone device was removed on day 6. Cloprotenol and eCG injections were applied as in Group 1. Additionally, on day 9, animals of group 2 received 0.01 mg buserelin acetate. Embryo transfer of in vivo or in vitro was done on day 16 and pregnancy diagnosis was realized by ultrasonography on days 23 and 53 after FTET. Statistical analyses were carried out using Chi-square tests and logistic regression. Pregnancy rate varied between farms (P0.05). However, the logistic regression determined that the only significant factor on pregnancy rate was the type of embryo. In conclusion, pregnancy rate in FTET females was higher for in vivo embryos than for in vitro embryos in cows evaluated under humid tropical conditions in Mexico.

Factors associated with pregnancy rate in fixed-time embryo transfer in cattle under humid-tropical conditions of México

The objective was to determine the effect of some factors on pregnancy rate of fixed-time embryo transfer (FTET), in cows and heifers kept under Mexican tropical conditions. Recipients females (n=405) grazing in pastures were selected according to breed group (Zebu and crosses), parity (nulliparous and multiparous), body condition score (BCS) and the presence of a corpus luteum (CL). The females were synchronized on day 0 using a progesterone vaginal device and 2 mg estradiol benzoate (EB), two groups were established. Group 1 (conventional protocol) were animals in which the progesterone device was removed on day 7. At this time, also received an injection of 50 mg cloprostenol sodium and 1 mg estradiol cypionate. Animals also received 300 IU (heifers) or 360 IU (cows) of eCG. Group 2 (J-Synch protocol) were animals in which the progesterone device was removed on day 6. Cloprotenol and eCG injections were applied as in Group 1. Additionally, on day 9, animals of group 2 received 0.01 mg buserelin acetate. Embryo transfer of in vivo or in vitro was done on day 16 and pregnancy diagnosis was realized by ultrasonography on days 23 and 53 after FTET. Statistical analyses were carried out using Chi-square tests and logistic regression. Pregnancy rate varied between farms (P<0.05). The highest pregnancy rate was for multiparous cows (66%). The recipient utilization rate was better in the J-Synch protocol (85%), and in vivo embryos (75%) had higher pregnancy rate. The diameter of the follicle and the CL had no effect on pregnancy rate (P>0.05). However, the logistic regression determined that the only significant factor on pregnancy rate was the type of embryo. In conclusion, pregnancy rate in FTET females was higher for in vivo embryos than for in vitro embryos in cows evaluated under humid tropical conditions in Mexico.(AU)

Induction of lactation: an economic study of tool for dairy heifers with successive reproductive failures / Indução de lactação: levantamento econômico da utilização desta ferramenta em novilhas leiteiras com sucessivas falhas reprodutivas

The aim of this study was to evaluate the economic viability of the use of a lactation induction protocol in Holstein heifers. Were collected data of nutritional, reproductive and sanitary management pre and post-lactation period from 30 induction heifers (IG) and 30 pregnant heifers (CG). All animals were inseminated around 14 months of age and started lactation at 23±4 months. The animals of IG were heifers do not pregnant after two inseminations and natural service e were induced to lactation according to protocol: from the 1st to the 8th day, 30 mg of estradiol benzoate were administered daily, together with 300 mg of progesterone. From the 9th until the 14th, animals only received daily doses of 20 mg estradiol benzoate. On 16th day, 0.56 mg of sodium cloprostenol was administered and injections of 40 mg of dexamethasone sodium phosphate were administered daily from the 19th to the 21st day. On the 1st, 8th, 15th and 22nd day, the animals received a dose of sometribove zinc. The animals of CG were managed according to the farm routine. The costs of the CG during pre and post lactation (nutrition, sanitary, reproduction management) e were higher than the IG, however, when evaluating the economic viability due to lower milk production, the induced group did not leave profit in the first year of use. When comparing the lactation induction with the sale of animals that did not conceive and purchase of animals for replacement, this last scenario showed itself as a better alternative.

O objetivo deste estudo foi avaliar a viabilidade econômica do uso de um protocolo de indução a lactação em novilhas da raça Holandês. Foram coletados dados econômicos do manejo nutricional, reprodutivo e sanitário pré e pós lactação de 30 novilhas induzidas à lactação (IG) e 30 novilhas prenhes (CG). Todos os animais foram inseminados em torno de 14 meses de idade e iniciaram a lactação com aproximadamente 23±4 meses. Os animais do IG foram novilhas que não conceberam após duas inseminações e monta natural, e foram induzidas à lactação com o protocolo: do 1° ao 8° dia receberam aplicação de 30 mg de benzoato de estradiol juntamente com 300 mg de progesterona. A partir do 9° dia até o 14° receberam 20 mg de benzoato de estradiol. No dia 16 ocorreu uma aplicação de 0.56 mg cloprostenol sódico e nos dias 19 ao 21, de 40 mg de dexametasona. Nos dias 1, 8, 15, e 22, os animais receberam 500 mg somatotropina recombinante bovina. Os animais do CG foram manejados conforme a rotina da propriedade. Os custos do CG durante o pré e lactação (nutrição, sanidade, reprodução) foram superiores ao grupo induzido. No entanto, ao avaliar a viabilidade econômica, devido a menor produção leiteira, o grupo induzido não deixou lucro na propriedade no primeiro ano de utilização. Ao comparar a indução de lactação com a venda de animais que não conceberam e a compra de animais para reposição, este último cenário mostrou-se como uma melhor alternativa.

Induction of lactation: an economic study of tool for dairy heifers with successive reproductive failures / Indução de lactação: levantamento econômico da utilização desta ferramenta em novilhas leiteiras com sucessivas falhas reprodutivas

The aim of this study was to evaluate the economic viability of the use of a lactation induction protocol in Holstein heifers. Were collected data of nutritional, reproductive and sanitary management pre and post-lactation period from 30 induction heifers (IG) and 30 pregnant heifers (CG). All animals were inseminated around 14 months of age and started lactation at 23±4 months. The animals of IG were heifers do not pregnant after two inseminations and natural service e were induced to lactation according to protocol: from the 1st to the 8th day, 30 mg of estradiol benzoate were administered daily, together with 300 mg of progesterone. From the 9th until the 14th, animals only received daily doses of 20 mg estradiol benzoate. On 16th day, 0.56 mg of sodium cloprostenol was administered and injections of 40 mg of dexamethasone sodium phosphate were administered daily from the 19th to the 21st day. On the 1st, 8th, 15th and 22nd day, the animals received a dose of sometribove zinc. The animals of CG were managed according to the farm routine. The costs of the CG during pre and post lactation (nutrition, sanitary, reproduction management) e were higher than the IG, however, when evaluating the economic viability due to lower milk production, the induced group did not leave profit in the first year of use. When comparing the lactation induction with the sale of animals that did not conceive and purchase of animals for replacement, this last scenario showed itself as a better alternative.(AU)

O objetivo deste estudo foi avaliar a viabilidade econômica do uso de um protocolo de indução a lactação em novilhas da raça Holandês. Foram coletados dados econômicos do manejo nutricional, reprodutivo e sanitário pré e pós lactação de 30 novilhas induzidas à lactação (IG) e 30 novilhas prenhes (CG). Todos os animais foram inseminados em torno de 14 meses de idade e iniciaram a lactação com aproximadamente 23±4 meses. Os animais do IG foram novilhas que não conceberam após duas inseminações e monta natural, e foram induzidas à lactação com o protocolo: do 1° ao 8° dia receberam aplicação de 30 mg de benzoato de estradiol juntamente com 300 mg de progesterona. A partir do 9° dia até o 14° receberam 20 mg de benzoato de estradiol. No dia 16 ocorreu uma aplicação de 0.56 mg cloprostenol sódico e nos dias 19 ao 21, de 40 mg de dexametasona. Nos dias 1, 8, 15, e 22, os animais receberam 500 mg somatotropina recombinante bovina. Os animais do CG foram manejados conforme a rotina da propriedade. Os custos do CG durante o pré e lactação (nutrição, sanidade, reprodução) foram superiores ao grupo induzido. No entanto, ao avaliar a viabilidade econômica, devido a menor produção leiteira, o grupo induzido não deixou lucro na propriedade no primeiro ano de utilização. Ao comparar a indução de lactação com a venda de animais que não conceberam e a compra de animais para reposição, este último cenário mostrou-se como uma melhor alternativa.(AU)

Comparison of estradiol benzoate and cypionate in Girolando cows submitted to a timed artificial insemination / Comparação do benzoato e do cipionato de estradiol em vacas Girolando submetidas à Inseminação Artificial em Tempo Fixo

The various studies on the manipulation of the estrous cycle culminated in the development of estrous and ovulation synchronization protocols, to the point of defining an optimum moment for artificial insemination. The induction of ovulation is a primordial part for the determination of the moment of the TAI, so to study which hormones and how they behave allows a better understanding of this physiological process and, to manipulate it efficiently. The aim of the present study was to compare the use of estradiol benzoate (EB) and cypionate (ECP) as ovulation inducer in Girolando cows submitted to Timed Artificial Insemination (TAI). Ovulations of 108 Girolando cows were synchronized and the initial day of treatment, recorded as D0, which was when the animals received an intravaginal device containing 1g of progestogen and an intramuscular application (im) of 2mg of EB. After 8 days (D8), the device was removed and 500µg of cloprostenol (im) was administered to all females. Then, the animals were randomly divided into two treatments: BG Group (n = 52) and CG Group (n = 56). The CG animals received 1mg of ECP (im) as the ovulation inducer at the time of device removal, while BG Group cows received 1mg of EB (im) 24 h later (D9). TAI occurred at D10. After device removal, ultrasound evaluations were performed every 12 h up to ovulation. The following reproductive parameters were evaluated: interval from intravaginal device removal to ovulation - IDO (hours); interval from ovulation to TAI-IOT (hours); diameter of the largest follicle at intravaginal device removal (mm); maximum diameter of the DF (mm) at D10; the dominant follicle growth rate (mm/day); synchronization rate - SR (%); ovulation rate - OR (%) and PR - pregnancy rate (%). Only the ovulation rate presented a statistical difference (p<0.05). In conclusion, despite the ovulation rate difference, both estradiol esters administered were effective and presented similar pregnancy rates in Girolando cows submitted to TAI.

Os diversos estudos sobre manipulação do ciclo estral culminaram com o desenvolvimento de protocolos de sincronização do estro e da ovulação, a ponto de se definir um momento ótimo para a inseminação artificial. A indução da ovulação é parte primordial para a determinação do momento da IATF. Dessa forma, estudar quais hormônios e como eles se comportam permite compreender melhor esse processo fisiológico e, ainda, manipulá-lo de forma eficiente. O objetivo do presente estudo foi comparar o uso de benzoato de estradiol (BE) e cipionato (ECP) em vacas Girolando submetidas à inseminação artificial em tempo fixo (IATF). As ovulações de 108 vacas Girolando foram sincronizadas e no início do tratamento, D0, os animais receberam um dispositivo intravaginal contendo 1g de progestágeno e uma aplicação intramuscular (im) de 2mg de BE. No D8, o dispositivo foi removido e 500µg de cloprostenol (im) foram administrados a todas as fêmeas. Depois disso, os animais foram divididos aleatoriamente em dois tratamentos: Grupo GB (n = 52) e Grupo GC (n = 56). Os animais do Grupo GC receberam 1mg de ECP (im) como indutor de ovulação no momento da retirada do dispositivo, enquanto as vacas do Grupo GB receberam 1mg de BE (im) 24 horas depois (D9). IATF ocorreu em D10. Após a remoção do dispositivo, as avaliações ultrassonográficas foram realizadas a cada 12 horas até a ovulação. Os parâmetros reprodutivos avaliados foram: intervalo entre a retirada do dispositivo intravaginal de P4 e a ovulação- IRD (horas); intervalo entre a ovulação e a IATF- IOI (horas); diâmetro do maior folículo na retirada do dispositivo intravaginal de P4 (mm); taxa de crescimento do FD-TCFD (mm/dia); taxa de sincronização - TS (%); taxa de ovulação- TO (%) e taxa de concepção - TC (%). Apenas a taxa de ovulação apresentou diferença estatística (p<0.05). Em conclusão, apesar da diferença na taxa de ovulação, ambos os ésteres de estradiol administrados foram eficazes e apresentaram taxas de prenhez semelhantes em vacas Girolando submetidas a IATF.