The aim of this study was to compare the fertility parameters in response to pregnant mare serum gonadotropin (conventional treatment) or gonadotrophin-releasing hormone (alternative treatment) in Romanov sheep subjected to a 7-d short-term protocol during non-breeding season. All sheep (n:57) were subjected to short-term synchronization protocol. Intravaginal sponge impregnated with 20 mg fluorogestone acetate was inserted for 7 days and all sheep received 125 µg cloprostenol at sponge removal. Sheep were randomly assigned to receive no additional treatment (CON, n:16), 240 IU pregnant mare serum gonadotropin (PMSG, n:24) at sponge removal or 10 µg buserelin acetate (GnRH, n:17) at 30 h after sponge removal. Natural mating was performed following detection of estrous with fertile eight Romanov rams. Estrous response, pregnancy rate, lambing rate, and litter size were compared among groups. Estrous response and pregnancy rate were 86% and 75.4% in all sheep, respectively. Estrous response was numerically higher about 7% (p>0.05) in treatment groups (PMSG, 87.5%; GnRH, 88.2%) than CON (81.2%). However, pregnancy rate was numerically higher (p>0.05) in PMSG (83.3%) than GnRH (70.6%) and CON (68.7%). Similarly, lambing rate in the PMSG (79.1%) was approximately 15% numerically greater (p>0.05) than in GnRH (64.7%) and CON (62.5%). In addition, litter size in PMSG (2.1) was also numerically higher (p>0.05) than GnRH (1.9) and CON (1.9).The use of GnRH provided similar estrous response compared to use of PMSG in Romanov sheep synchronized with short-term protocol. However, use of PMSG provided numerically higher pregnancy rate, lambing rate, and litter size than use of GnRH. Considering the serious ethical concerns and animal welfare for the production of PMSG, it is necessary to use alternative gonadotropins. Comprehensive studies are needed to compare the fertility parameters between application of PMSG and GnRH in Romanov sheep.

The objective of this experiment was to study wheather the administration of GnRH plus PGF2 alpha synchronizes the estrus in anestrus crossbred cows exposed to bull urine (BU) during the winter season (Nov to Feb). The results indicated that a greater proportion of BU-exposed cows (n=20) showed estrus as compared to control (n=8) (90 vs 37.5 % P0.05). The mean plasma progesterone concentration remained below 1ng/ml in all animals of each group during the treatment period. The overall conception rate was double in BU-exposed cows (66.7 vs 33.3 % P0.05). From this experiment it can be concluded that oro-nasal application of BU synchronizes the estrus in a greater proportion of anestrus cows treated with GnRH plus PGF2 alpha during winter season.

Follicle like structures with a minimum of 17 mm diameter and persisting for more than 6 days in the absence of corpus luteum is called as follicular cyst. It is the hypothalamo-hypophyseo gonadal axis that governs the reproductive events primarily. Plasma is a medium that reflects the changes in any organ apart from providing nutrients and draining the metabolic wastes. Cows brought for infertility treatment were screened and cows which were diagnosed as follicular cyst randomly allotted in to four groups of eight cows each. Different groups were subjected to different treatment protocols viz, Regular co-synch protocol, modified co-synch protocol, Trans-gluteal follicular cyst evacuation technique and trans-gluteal follicular cyst evacuation technique cum modified co-synch protocol for Group I, II, III and IV, respectively. Blood samples were collected from all the cows of different groups on day 0 (initiation of treatment), 7 and 9 of treatment and were analyzed for biochemical parameters. Cholesterol, triglyceride, total protein, calcium and phosphorus concentration was quantified using an automatic analyser UV-VIS spectrophotometer. There was no significant difference (P > 0.05) noticed between the mean concentration of biochemical parameters of different treatment groups, on days 0 and 7 in serum. The mean concentrations of cholesterol were 116.13±20.28, 59.67±10.50, 70.88±6.57 and 64.00±8.36 mg/dl in Group I, II, III and IV cows, respectively and were significantly (P < 0.05) higher in Group I. The mean concentration of all other biochemical parameters were non-significant (P > 0.05) between all treatment groups, on day 9 in serum. This might be due to steroid bio transformation of cholesterol. 

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 ;0.05). 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). 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 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;0,05). 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). 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.

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 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.