Abstract Currently, gonadotropin products (follicle stimulating hormone, FSH, and luteinizing hormone, LH) used in animal reproduction are produced by extraction and purification from abattoir-derived pituitary glands. This method, relying on animal-derived materials, carries the potential risk of hormone contamination and pathogen transmission. Additionally, chorionic gonadotropins are extracted from the blood of pregnant mares (equine chorionic gonadotropin; eCG) or the urine of pregnant women (human chorionic gonadotropin; hCG). However, recent advancements have introduced recombinant gonadotropins for assisted animal reproduction therapies. The traditional use of FSH for superovulation has limitations, including labor requirements and variability in superovulation response, affecting the success of in vivo (SOV) and in vitro (OPU/IVEP) embryo production. FSH treatment for superstimulation before OPU can promote the growth of a homogenous follicular population and the recovery of competent oocytes suitable for IVEP procedures. At present, a single injection of a preparation of long-acting bovine recombinant FSH (rFSH) produced similar superovulation responses resulting in the production of good-quality in vivo and in vitro embryos. Furthermore, the treatment with eCG at FTAI protocol has demonstrated its efficacy in promoting follicular growth, ovulation, and P/AI, mainly in heifers and anestrous cows. Currently, treatment with recombinant glycoproteins with eCG-like activity (r-eCG) have shown promising results in increasing follicular growth, ovulation, and P/AI in cows submitted to P4/E2 -based protocols. Bovine somatotropin (bST) is a naturally occurring hormone found in cows. Recombinant bovine somatotropin (rbST), produced through genetic engineering techniques, has shown potential in enhancing reproductive outcomes in ruminants. Treatment with rbST has been found to improve P/IA, increase donor embryo production, and enhance P/ET in recipients. The use of recombinant hormones allows to produce non-animal-derived products, offering several advantages in assisted reproductive technologies for ruminants. This advancement opens up new possibilities for improving reproductive efficiency and success rates in the field of animal reproduction.

Abstract Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane. In addition to enteric methane (CH4) produced by the rumen, cattle production also contributes carbon dioxide (CO2) (feed), nitrous oxide (N2O) (feed production, manure) and other CH4 (manure) to the total greenhouse gas (GHG) budget of beef and dairy production systems. The relative contribution in standard dairy systems is typically enteric CH4 58%, feed 29% and manure 10%. Herds with low production efficiency can have an enteric CH4 contribution up to 90%. Digestibility of feed can impact CH4 emission intensity. Low fertility herds also have a greater enteric CH4 contribution. Animals with good feed conversion efficiency have a lower emission intensity of CH4/kg of meat or milk. Feed efficient heifers tend to be lean and have delayed puberty. Fertility is a major driver of profit in both beef and dairy cattle, and it is highly important to apply multi-trait selection when shifting herds towards improved efficiency and reduced CH4. Single nucleotide polymorphisms (SNPs) have been identified for feed efficiency in cattle and are used in genomic selection. SNPs can be utilized in artificial insemination and embryo transfer to increase the proportion of cattle that have the attributes of efficiency, fertility and reduced enteric CH4. Prepubertal heifers genomically selected for favourable traits can have oocytes recovered to produce IVF embryos. Reproductive technology is predicted to be increasingly adopted to reduce generation interval and accelerate the rate of genetic gain for efficiency, fertility and low CH4 in cattle. The relatively high contribution of cattle to anthropogenic global methane has focussed attention on strategies to reduce enteric CH4 without compromising efficiency and fertility. Assisted reproductive technology has an important role in achieving the goal of multiplying and distributing cattle that have good efficiency, fertility and low CH4.

RESUMO: 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.

ABSTRACT: 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.

Abstract Artificial insemination (AI) and embryo transfer (ET) are the most widely used biotechnologies in the world with the goal of increasing genetic gain and improving reproductive efficiency of beef and dairy herds. The protocols for ovulation synchronization for timed AI (TAI) or ET (TET) are tools that allow artificial insemination or transfer of a high number of embryos in a pre-established moment and without the necessity of estrous detection. Currently, 86% of inseminations in Brazil are performed using TAI (13.6 million TAI out of a total of 15.4 million doses of semen marketed in 2018). With the use of TAI, it was possible to verify that the percentage of artificially inseminated females in Brazil went from 5.8% in 2002 to 13.1% in 2018. The ET market also presented considerable growth in the last 20 years. There was an increase of approximately 8 fold in the number of produced embryos, escalating from 50,000 in 1999 to 375,000 in 2017. In this period, there was a significant increase on the in vitro embryo production, which represented 92.1% of embryos produced in Brazil in 2017. Also, in this period, there was an increase on the embryo production of dairy breeds and reduction on the embryo production of zebu breeds in comparison to data from the early 2000’s. TET increases significantly the number of recipients suitable to receive an embryo. After synchronization, 75 to 85% of recipients present a suitable CL for ET without estrous detection. Currently, many synchronization and resynchronization protocols for TAI/TET have been studied to attend different managements, breeds and animal categories, with predictable and satisfactory results. With the intensification of the use of these biotechnologies, it is possible to obtain elevated reproductive efficiency with increase on the genetic gain, which determines greater productivity and economic return for dairy and beef farms. However, the challenge to keep the market growing in the next decade could depend on some factors, such as: increase of the extension services for producers and of the extension training for specialists, improvement of the technological advances to develop more efficient and cost-effective products and practical protocols, increase the integration between universities, research institutes, veterinarians and industries and also, asses market demand for production of animal protein with higher quality, efficiency and environmental and economic sustainability.

Avaliaram-se os efeitos da remoção temporária de bezerros (RTB) ou da aplicação de gonadotrofina coriônica eqüina (eCG) na taxa de prenhez (TP) de vacas Nelore lactantes tratadas com um dispositivo intravaginal liberador de progesterona (DILP). No experimento 1, 83 vacas Nelore e 102 mestiças (Nelore × Red Angus) foram distribuídas em três grupos. Em dia aleatório do ciclo estral (D0), os animais do grupo 1 foram tratados com benzoato de estradiol (BE; 2,5 mg, IM, Estrogin®) e um DILP (1 g de progesterona, DIB®), removido no D9, quando também se administrou d-cloprostenol (150 µg, IM, Prolise®) e aproximadamente 12 horas após identificação do estro realizou-se a inseminação artificial. No grupo 2 (IATF), o tratamento foi semelhante ao aplicado no grupo 1, porém, administrou-se uma segunda dose de benzoato de estradiol (1 mg) no D10 e 30-36 horas mais tarde realizou-se a inseminação artificial em tempo fixo (IATF). No grupo 3 (IATF/RTB), os bezerros foram removidos a partir do D9 até a inseminação artificial com tempo fixo (IATF). As taxas de prenhez para as vacas Nelore e mestiças foram, respectivamente, de 7,69 e 41% (Controle); 23,52 e 59,57% (IATF); 69,44 e 55,81% (IATF/RTB). No experimento 2, 255 vacas Nelore lactantes foram distribuídas em três grupos. Os animais do grupo 4 (IATF) foram tratados com benzoato de estradiol (2 mg) e um DILP (1,9 g de progesterona, CIDR-B®) no D0 e no D8 sofreram remoção do DILP no D8 e administração de 25 mg de dinoprost (IM, Lutalyse®). No D9, foi aplicado benzoato de estradiol (1 mg) realizando-se a IATF 30-36 horas mais tarde. No grupo 5 (IATF/RTB), os bezerros foram removidos no D9 até a IATF. O grupo 6 (eCG) foi semelhante ao IATF, exceto pela aplicação de eCG no D9 (400 UI, IM, Novormon®). As taxas de prenhez foram de 50,57 (IATF), 53,57 (IATF/RTB) e 54,76% (eCG). A associação de RTB ao tratamento hormonal com DILP aumenta as taxas de prenhez, enquanto a adição de eCG ao tratamento não melhora as taxa de prenhez de vacas Nelore lactantes ciclando e em boa condição corporal.

This study aimed to evaluate the effects of temporary calf removal (TCR) or eCG administration on pregnancy rates of milking Nelore cows treated with a intravaginal progesterone releasing device (IPRD). In the first experiment 83 Nelore and 102 Nelore vs. Red Angus crossbred cows were randomly allocated to 3 groups. Animals in Group 1 (CON) received estradiol benzoate (EB; 2.5 mg, i.m., Estrogin®) and an IPRD (1g progesterone, DIB®) in a random stage of the estrous cycle (D0). At D9 the IPRD was removed and the animals were treated with d-cloprostenol (150µg, i.m., Prolise®). The animals were artificially inseminated (AI) 12 h after estrus detection. Group 2 (FTAI) was similar to CON, except that another dose of EB (1mg) was administered at D10, and 30-36 hours later artificial insemination (FTAI) was performed at a fixed time. In Group 3 (FTAI/TCR) the calves were removed from D9 to the FTAI. Pregnancy rates for Nelore and crossbred cows were, respectively, 7.69 and 41% (CON); 23.52 and 59.57 (FTAI); 69.44 and 55.81 (FTAI/TCR). In the second experiment, 255 lactating Nelore cows were allocated to 3 groups. At D0, animals in Group 4 (FTAI) received EB (2 mg) and one IPRD (1.9g progesterone, CIDR-B®), which was removed at D8 when the cows received 25 mg of dinoprost (i.m., Lutalyse®). At D9 EB (1 mg) was administered and 30-36 hours later all animas were FTAI. In Group 5 (FTAI/TCR) the calves were removed from D9 to FTAI. The Group 6 (eCG) was similar to IATF except for the administration of eCC in D9 (400 IU, i.m., Novormon®). Pregnancy rates were: 50.57% (FTAI), 53.57% (FTAI/TCR) and 54.76% (eCG). These results indicated that TCR associated with IPRD increase pregnancy rates, whereas the addition of eCG to IPRD do not improve pregnancy rates in Nelore cows which are cycling and in lactation with good body condition.

Objetivou-se avaliar a eficiência da sincronização da ovulação para inovulação em tempo fixo em novilhas Bos taurus indicus x Bos taurus taurus receptoras de embrião. No Experimento 1, a dinâmica folicular foi acompanhada durante o protocolo "Ovsynch" (G1; n=35) e após a aplicação de PGF2alfa (G2; n=34). No Experimento 2, os mesmos tratamentos foram realizados a campo em 168 (G1) e 177 (G2) novilhas. No D6, colheu-se sangue para dosagem de P4 e se realizaram exames ultra-sonográficos. No D7, realizou-se a inovulação. No Experimento 1, 45,7% dos animais ovularam após o 1º GnRH (P<0,05) e 74,3% após o 2º. A taxa de ovulação foi de 58,8% no G2. Foram detectadas em estro 64,7% das novilhas no G2 e 22,9% no Gl (P<0,01). No Experimento 2, observaram-se mais receptoras aptas a inovulação no Gl que no G2 (72,6% vs. 45,2%; P<0,01). A taxa de concepção foi de 49,2% para o Gl e de 56,3% para o G2 (P>0,05). Ao final, a taxa de prenhez no Gl foi de 35,7% e no G2 de 25,4% (P<0,05). Foram detectadas em estro 53,7% das novilhas do G2 e 33,3% do Gl (P<0,05). Os corpos lúteos com maior área determinaram maiores concentrações de P4 e taxa de concepção (P<0,05). A sincronização da ovulação para inovulação em tempo fixo aumentou as taxas de ovulação, de aproveitamento e de prenhez em novilhas receptoras de embrião.

The aim of this study was to evaluate the efficacy of the synchronization of ovulation for fixed-time embryo transfer in crossbred recipient heifers (Bos taurus indicus x Bos taurus taurus). At Experiment 1, ovarian ultrasonography was performed to evaluate follicular dynamics during the "Ovsynch" protocol (G1; n=35) or single PGF2alpha injection (G2; n=34). At Experiment 2, the same treatments were used at field conditions in 168 (G1) and 177 (G2) heifers. On D6, ovarian ultrasonography and blood collection for P4 assay were performed. On D7, a embryo was transferred. At Experiment 1, 45.7% of the heifers ovulated after the 1st and 74.3% after the 2nd GnRH injection (P<0.05). The ovulation rate in G2 was 58.8%. In G2, 64.7% of the heifers were detected in estrus and in Gl, 22.9% (P<0.01). At Experiment 2, Gl had more selected heifers for embryo transfer than G2 (72.6% vs. 45.2%; P<0.01). Conception rates were 49.2% and 56.3% in G1 and G2, respectively (P>0.05). Thus, the pregnancy rate in Gl was 35.7% and 25.4% in G2 (P<0.05). Estrus was detected in 53.7% of the recipients in G2 and 33.3% in those of the Gl (P<0.05). It was verified that CL with larger area induced an increase on P4 concentration and on the conception rate of both groups (P<0.05). The synchronization of ovulation for fixed-time embryo transfer increased the ovulation, the selection and the pregnancy rates in recipient heifers.

O objetivo desse estudo foi avaliar eficiência do protocolo de sincronização da ovulação (GnRH/PGF2alfa/GnRH) para inseminação artificial em tempo fixo em bubalinos. No Experimento 1, trinta e três búfalas com 60 dias pós-parto, foram separadas em dois grupos para avaliação da dinâmica folicular (Grupo 1, n = 16, 10mg de GnRH/15mg de PGF2alfa/10mg de GnRH; Grupo 2, n = 17, 20mg de GnRH/PGF2alfa/10mg de GnRH). Exames ultra-sonográficos foram realizados de 12 em 12 horas para verificar a resposta ovariana à primeira aplicação de GnRH. Outras avaliações foram realizadas nos dias da aplicação da PGF2alfa e do segundo GnRH. Em seguida, foram realizados exames de 6 em 6 horas até o momento da ovulação. Foram colhidas amostras de sangue nos dias das aplicações para avaliar as concentrações de progesterona no momento das administrações hormonais. No Experimento 2, foi verificada a eficiência da sincronização da ovulação para inseminação artificial em tempo fixo (16 horas após o segunda dose de GnRH, n=1053), durante as estações reprodutiva favorável e desfavorável, nos anos de 1998 e 1999. Os animais receberam 20mg de GnRH/PGF2alfa/10mg de GnRH. Ainda, foi analisada a influência da condição corporal, ordem de partos, período pós-parto ao início do tratamento, ano e a estação reprodutiva (favorável ou desfavorável), sobre a taxa de concepção. No Experimento 1, verificou-se que 33,0 ± 8,3h após a primeira aplicação de GnRH, 60,60% dos animais ovularam (Grupo 1 = 70,5 vs. Grupo 2 = 50,00%; P>0,05). A dose de GnRH (10mg vs. 20mg) e a concentração de progesterona no início do tratamento não interferiu na ovulação (P>0,05). Os animais que ovularam (n = 20) após a primeira aplicação de GnRH apresentaram maior diâmetro folicular (P<0,01) que aqueles que não ovularam (n=13). Na aplicação de PGF2alfa, o diâmetro folicular médio foi de 10,3 ± 2,0mm. O Grupo 1 apresentou maior diâmetro folicular que o Grupo 2 (P<0,01). Os animais que ovularam após a primeira aplicação de GnRH (n=20) apresentaram maiores concentrações de progesterona no dia da aplicação da PGF2alfa (P<0,05). Notou-se que 78,80% dos animais tratados apresentaram ovulação sincronizada sendo que, a primeira dose de GnRH não interferiu na eficiência do protocolo (P>0,05). No Experimento 2, observou-se taxa de concepção de 45,40% (n = 1053). Animais sincronizados durante a estação reprodutiva favorável apresentaram melhores taxas de concepção quando comparados ao período desfavorável (48,80% vs. 6,90%; P < 0,05). A taxa de concepção foi influenciada pela condição corporal dos animais e pela ordem de partos durante a estação reprodutiva favorável (P<0,05). As taxas de concepção não diferiram conforme o ano (1998 e 1999) de realização das inseminações artificiais e o período pós-parto no início do tratamento hormonal (P>0,05). Em conclusão, os Experimentos indicaram que a utilização da sincronização da ovulação para inseminação artificial em tempo fixo, durante a estação reprodutiva favorável, apresenta resultados satisfatórios em bubalinos, podendo ainda ser melhorados quando utilizadas búfalas multíparas com bom estado corporal no início do tratamento.

The objective of this study was to evaluate the efficiency of synchronization ovulation protocol (GnRH/PGF2alpha/GnRH) for fixed timed insemination in buffalo. In Experiment 1, thirty-three female buffaloes with 60 days postpartum, were divided in two groups for evaluation of the follicular dynamics (Group 1, n = 16, 10mg of GnRH/15mg of PGF2alpha/10mg of GnRH; Group 2, n = 17, 20mg of GnRH/15mg of PGF2alpha/10mg of GnRH). Ultrasonography exams were performed every 12 hours to verify the ovarian response to the first GnRH injection. Another evaluations were performed on PGF2a injection and second GnRH injection. After last hormonal injection, ultrasonography exams were performed every 6 hours to verify the moment of the ovulation. Blood samples were collected on Days 0, 7 and 9 to evaluate the progesterone concentrations at the moment of the hormonal injections. In Experiment 2, the efficiency of the synchronization of ovulation was verified for fixed timed insemination (16 hours after second GnRH injection, n=1053), during the favorable and unfavorable reproductive season, in the years of 1998 and 1999. Animals received 20mg of GnRH/15mg of PGF2alpha/10mg of GnRH. Besides, also recorded and evaluated aspects like body condition score, parity, postpartum period, year and the reproductive season (favorable or unfavorable season), on the conception rate. In Experiment 1, it was verified that 33.0 ± 8.3h after the first GnRH injection, 60.60% of the animals ovulated (Group 1 = 70.5 vs. Group 2 = 50.00%; P>0.05). The dose of GnRH (10mg vs. 20mg) and the progesterone concentration did not interfere in ovulation in the beginning of the treatment (P>0.05). Animals that ovulated (n = 20) after the first GnRH injection presented larger follicular diameter (P <0.01) that those that no ovulated (n=13). In PGF2alpha injection, the follicular diameter was 10.3 ± 2.0mm. The Group 1 presented larger follicular diameter than the Group 2 (P <0.01). Animals that ovulated after the first GnRH injection (n=20) presented higher progesterone concentrations in the day of PGF2alpha injection (P <0.05). It was observed that 78,80% female buffaloes treated presented synchronized ovulation and, the first dose of GnRH did not interfere in the efficiency of the protocol (P>0.05). In Experiment 2, it was observed conception rate of 45.40% (n = 1053). Animals synchronized during the favorable reproductive season presented better conception rate than the unfavorable season (48.80% vs. 6.90%; P <0.05). The conception rate was influenced by body condition score of the animals and parity during the favorable reproductive season (P <0.05). The conception rates did not differ according to the year (1998 and 1999) of artificial inseminations and the postpartum period in the beginning of the treatment (P>0.05). In summary, the Experiments indicated that the use of synchronization of the ovulation for fixed timed insemination, during the favorable reproductive season, presents satisfactory results in buffalo and could still be better when used multiparous buffaloes with good body conditon score in the beginning of the treatment.

O objetivo desse estudo foi avaliar a eficiência da meia dose de PGF2alfa no protocolo de sincronização da ovulação (GnRH/PGF2alfa/GnRH) para inseminação artificial em tempo fixo em bubalinos. Foram utilizadas 262 búfalas (³ 40 dias pós-parto), divididas em dois grupos (Grupo 1, n = 125, GnRH/ ½ dose de PGF2alfa/GnRH; Grupo Controle, n = 137, GnRH/PGF2alfa/GnRH). Os animais do Grupo 1 receberam 25 mg de GnRH IM (Lecirelina, Gestran-plus®) e, após sete dias, receberam 75mg de PGF2alfaIM (d-cloprostenol, Preloban®). Dois dias após a aplicação da PGF2alfa, esses animais receberam 25mg de GnRH IM (Lecirelina). Os animais do Grupo Controle receberam o mesmo tratamento, à exceção da dose de PGF2alfa (150mg de d-cloprostenol, Preloban®). Todos os animais foram inseminados em tempo fixo 16 horas após a segunda aplicação de GnRH. Foram colhidas amostras de sangue de 35 búfalas do Grupo 1 e de 30 do Grupo Controle nos dias da aplicação de PGF2alfa e da segunda dose de GnRH. As colheitas de sangue foram realizadas para avaliar as concentrações plasmáticas de progesterona. Os resultados demonstraram que a taxa de concepção não foi influenciada pela dose de PGF2alfa (P>0,05). As taxas de concepção dos Grupos 1 e Controle foram de 48,00% (60/125) e 40,90% (56/137), respectivamente. Observou-se que 88,60% (n = 35) das búfalas do Grupo 1 e 90,00% (n = 30) do Grupo Controle apresentaram luteólise 48 horas após a aplicação de PGF2alfa (P>0,05). Em conclusão, os resultados indicaram que ambos tratamentos proporcionaram aceitáveis taxas de concepção. Dessa forma, a dose recomendada de PGF2alfa pode ser reduzida pela metade no protocolo de sincronização da ovulação para inseminação artificial em tempo fixo em bubalinos.

The objective of this study was to evaluate the efficiency of half dose of PGF2alpha in the synchronization of ovulation protocol (GnRH/PGF2alpha/GnRH) for fixed-time artificial insemination in buffalo. Two hundred and sixty two buffaloes (³40 days postpartum) were divided in 2 groups (Group 1, n = 125, GnRH/ ½ dose de PGF2alpha/GnRH; Control Group, n = 137, GnRH/PGF2alpha/GnRH). Animals in Group 1 received 25mg of GnRH IM (Lecirelin, Gestran-plus®) and, seven days later, half dose of PGF2alpha IM (75mg d-cloprostenol, Preloban®). Two days after PGF2alpha injection, all animals received 25mg of GnRH IM (Lecirelin). Animals in Control Group received the same treatment, except for the dose of PGF2alpha(150mg, IM, d-cloprostenol, Preloban®). All animals were fixed-time inseminated 16 hours after the second GnRH injection. Blood samples were collected from 35 buffaloes in Group 1 and 30 buffaloes in Control Group on day of PGF2alpha and second GnRH injections to measure plasma progesterone concentrations. Conception rate was not influenced by PGF2alpha dosage (P>0.05). Conception rates were 48.00% (60/125) and 40.90% (56/137) in Group 1 and Control Group, respectively. It was observed that 88.60% (n = 35) of the buffaloes in Group 1 and 90.00% (n = 30) in Control Group presented luteolysis 48 hours after the PGF2alpha injection (P>0.05). In summary, present data show that both treatments result in acceptable conception rates. Therefore, the recommended dose of PGF2alpha can be reduced in 50.00% in the synchronization of ovulation protocol for fixed-time artificial insemination in buffalo.

O uso de protocolos de sincronização da ovulação em bubalinos é bastante vantajoso, em virtude de certas peculiaridades apresentadas pela espécie que podem prejudicar programas de inseminação artificial, como a baixa incidência de comportamento homossexual e relações de dominância entre os animais. Com o objetivo de verificar a eficácia da Lecirelina como agonista de GnRH no protocolo GnRH/PGF2alfa/GnRH, 270 búfalas, com período pós-parto entre 45 e 60 dias, mantidas a pasto em duas propriedades, foram submetidas a dois tratamentos de sincronização da ovulação. Os animais do Grupo 1 (n = 132) receberam, em dia desconhecido do ciclo estral, 20 µg de Buserelina IM, sendo aplicados, 7 dias mais tarde, 15 mg de prostaglandina (PGF2a). Dois dias após a administração da PGF2alfa, os animais receberam 10 µg de Buserelina, IM. As fêmeas do Grupo 2 (n = 138) foram tratadas seguindo o mesmo protocolo, com a diferença de que, na primeira e na terceira administrações hormonais, se aplicaram, respectivamente, 50 µg e 25 µg de Lecirelina, IM. A inseminação artificial foi efetuada em tempo fixo, 16 horas após a terceira administração hormonal, em ambos os grupos. O diagnóstico de gestação foi realizado por ultra-sonografia, 30 dias após a inseminação artificial. As taxas de concepção foram semelhantes [47,0% (62/132) e 50,0% (69/138) nos Grupos 1 e 2 (P > 0,05)]. Não foi observado efeito da propriedade (P > 0,05) nas taxas de concepção. Os resultados demonstram que é possível utilizar Lecirelina para promover a sincronização da ovulação de bubalinos, com resultados satisfatórios.

Buffalo has peculiar reproductive patterns, which make artificial insemination programs a hard and expensive task. Artificial insemination in fixed time is advantaged because females show low incidence of homosexual behaviour and strong dominance relationships, which leads to a poor accuracy in estrus detection. The aim of this experiment was to compare the efficiency of two different GnRH agonists in the GnRH/PGF2alpha/GnRH protocol (Buserelin vs Lecirelin). Two hundred and seventy buffaloes with 45 to 60 days postpartum were synchronized and fixed-time inseminated. The animals were kept on pasture in two farms at São Paulo and Mato Grosso do Sul (Brazil). Cows in Group 1 (n = 132) received, intramuscularly, 20 µg of Buserelin at a random day of the estrous cycle and, seven days later, 15 mg of prostaglandin F2alpha. Two days after prostaglandin administration, 10 µg Buserelin were intramuscularly injected. Cows in Group 2 (n = 138) were treated with the same protocol, but with intra-muscular administrations of Lecirelin (50 µg in the first administration and 25 µg in the second). Artificial insemination was performed 16 hours after the last injection in both groups. Pregnancies were diagnosed by ultrasonography (Pie Medical 480, 5.0 and 7.5 MHz linear probe), 30 days after artificial insemination. Conception rates were not influenced by farm (P > 0.05) and were similar in both groups [Group 1: 47.0% (62/132); Group 2: 50.0% (69/138); P > 0.05]. Results show that Lecirelin is as efficient as Buserelin to synchronize ovulation for fixed-time artificial insemination in buffaloes.

O desempenho de um ELISA comercial (Bovine Rhinotracheitis virus antibody test Kit, Herdcheck®, IDEXX Laboratories Inc., USA) para a identificação de anticorpos anti-herpesvírus bovino tipo 1 (BHV-1), em soro bovino, foi avaliado em 133 amostras de soro de búfalos (Bubalus bubalis), sem histórico de vacinação para IBR, da Região do Vale do Ribeira, Estado de São Paulo. Tomando-se a técnica de soroneutralização como referência, o ELISA indireto apresentou sensibilidade e especificidade relativa de 97,14 e 46,03%, respectivamente. A concordância estimada pelo índice kappa, entre os dois métodos, foi de 0,44 IC (0,29-0,59), utilizando um intervalo de confiança de 95%.

The performance of a commercial ELISA (Bovine Rhinotracheitis virus antibody test Kit, Herdcheck®, IDEXX Laboratories Inc., USA) designed to detect the presence of antibody to the Bovine Herpesvirus type 1 (BHV-1) in bovine serum, was evaluated in samples of buffaloes (Bubalus bubalis) serum. Sera of 133 buffaloes without IBR vaccination were performed both by ELISA and standard serum neutralization technique. Sensitivity and specificity of ELISA were 97.14% and 46.03%, respectively. The estimated concordance between two serologic diagnostic methods by kappa index was 0.44 IC (0.29-0.59) using 95% confidence level.

Mensurações pélvicas internas e externas foram realizadas in vivo em 255 búfalas mestiças. Para a pelvimetria interna, utilizou-se o pelvímetro de Menissier-Vissac. Os resultados foram confrontados com a idade, perímetro torácico, peso, altura e comprimento. Para comparação das medidas pélvicas, os animais foram divididos equitativamente em 3 grupos (n=85), segundo a ocorrência e freqüência de partos (nulíparas, primíparas e multíparas). Os diâmetros pélvicos internos: biilíacos superior e inferior (horizontais) e sacropúbico (vertical) apresentaram respectivamente as seguintes médias e desvios padrões: 17,1 ± 2,17 cm; 15,7 ± 2,11 cm e 22,3 ± 2,51 cm; e os externos: biilíaco, biisquiático e ilioisquiático, da mesma maneira: 59,8 ± 6,13 cm; 32,4 ± 3,56 cm e 44,5 ± 3,31 cm. Correlações positivas significantes (p < 0,01) foram verificadas entre todas as medidas, porém, dentre as medidas corpóreas gerais, o perímetro torácico revelou o mais alto índice de correlações com as medidas pélvicas internas e externas. Diferenças significativas (p < 0,05) entre os 3 grupos foram observadas em relação à pelvimetria interna, quando comparados através das médias ajustadas em função do perímetro torácico, porém em relação à pelvimetria externa somente entre as nulíparas e os demais grupos para os diâmetros biilíaco e ilioisquiático. Para o diâmetro biisquiático externo nenhum dos grupos revelou tais diferenças. A pelvimetria interna em relação à externa mostrou-se menos correlacionada com o desenvolvimento corpóreo e mais nitidamente influenciada pela ocorrência dos sucessivos partos.

In vivo internal and external pelvimetry was carried out in 255 mixed female buffaloes. A Menissier-Vissac pelvimeter was used for the internal measurements. The results were compared to age, heart girth, body weight, height and length. In order to compare the pelvic measurements, the animals were equitably divided into 3 groups (n=85) according to parturition occurrence and frequency (nuliparous, primiparous and multiparous). The internal transverse (horizontal) pelvic diameters, dorsal and ventral bi-iliac and the sacro-pubic (vertical) were respectively: 17.1 ± 2.17 cm; 15.7 ± 2.11 cm and 22.3 ± 2.51 cm; and the external bi-iliac (hipwidth), bi-isquiatic (pin width) and ilioisquiatic (rump length): 59.8 ± 6.13 cm; 32.4 ± 3.56 cm and 44.5 ± 3.31 cm, respectively. Significant positive correlations (p < 0.01) were obtained for all measurements but heart girth was found to have the highest correlations to pelvic measurements. Adjusted means by heart girth revealed significant differences (p < 0.05) for the 3 groups in respect to internal pelvimetry. However, as it concerns to external pelvimetry, significant differences were found only between the nuliparous and the other two groups for the bi-iliac and ilioisquiatic; for the bi-isquiatic diameter no significant differences were found. The internal pelvimetry was found to be less correlated to the body size and more evidently affected by the successive parturition occurrence.