Reproductive parameters of Sindhi cows (Bos taurus indicus) treated with two ovulation synchronization protocols

Abstract

-The objective of this study was to evaluate the reproductive parameters of Sindhi cows aiming to improve the efficiency of fixed-time artificial insemination protocols in this breed. For this purpose, sixteen Sindhi cows were divided into two groups: in group I (EB, n = 8) animals received an intravaginal P4 implant and an application of 2 mg of estradiol benzoate on day 0. On day 8 the implant was removed and 10 mg of Dinoprost were applied; on day 9, 1 mg of estradiol benzoate was applied, and animals were fixed-time artificially inseminated 36 hours later; in group II (EB + eCG, n = 8) animals were subjected to same treatment, and on day eight 400 IU of eCG were applied. From day 0 animals were examined daily by a trans-rectal ultrasound device, where in each assessment the largest follicles of each day were measured. The reproductive parameters observed for groups I and II were: emergence of follicular wave, 4.5±1.4 and 3.8±0.3 days; interval between wave emergence and ovulation, 5.8±1.4 and 7.1±0.3 days; interval between wave emergence and implant removal, 3.5±1.4 and 4.1±0.3 days; interval between implant removal and ovulation, 74.0±11.8 and 82.5±4.2 hours; diameter of the dominant follicle (DF) at the time of implant removal, 7.5±2.5 and 6.6±1.5 mm; maximum diameter of DF, 10.47±8.85 and 3.7±1.2 mm; growth rate of DF, 0.90±0.83 and 0.7±0.6 mm/day; ovulation rate, 75% and 100%; and pregnancy rate, 0% and 50%, respectively. There was no significant difference between the groups. We observed that eCG was not efficient in improving the reproductive parameters analyzed in this breed.

Principal component and cluster analyses of production and fertility traits in Red Sindhi dairy cattle breed in Brazil

“…Later, those animals were identified as belonging to the Red Sindhi breed. In a second moment, there was an official importation of 28 females and 3 males selected from purebred Red Sindhi herds in Pakistan, which arrived at the Brazilian island of Fernando de Noronha in the year 1952, whereas the establishment of the Brazilian Red Sindhi herds was based on these two small founder populations only (Leite et al 2001;Moura et al 2009;Mello et al 2013;ABCZ 2014;Silva et al 2014).…”

Effects of dexamethasone on growth, viability and ultrastructure of bovine secondary follicles cultured in vitro

“…According to Saraiva et al (2010), this interaction between follicular cells and oocyte cells represented important communication and signalling responses between granulosa cells and oocytes through gap junctions. These transitions occurred through structures known as transient projections, which allow the bidirectional transport of ions and metabolites that regulate growth of oocytes (Mello et al, 2013;Clarke, 2018). In addition, a large numbers of mitochondria in the oocytes of cultured follicles reinforced the maintenance of oocyte integrity (Sun et al, 2001).…”

Inseminação artificial e inseminação artificial em tempo fixo em bovinos

“…Outro ponto marcante no desenvolvimento das pesquisas com IATF em gado de corte está relacionado ao uso da gonadotrofina coriônica equina (eCG) na composição dos protocolos para a sincronização da ovulação. Estudos relacionados apontam para ganhos significativos em taxa de prenhez na estação de monta de fêmeas zebuínas, sobretudo quando estão em anestro, demonstrando assim a sua viabilidade econômica frente a eficiência reprodutiva proporcionada (SÁ FILHO et al, 2010;SALES et al, 2011;MELLO et al, 2013;MELLO et al, 2014) Pesquisas na área de fisiologia reprodutiva têm melhorado e refinado os sistemas de IA e de sincronização da ovulação tornando-os mais baratos e eficientes. Hoje, em função de várias pesquisas, existem diversos protocolos envolvendo diferentes associações de hormônios e de manejo que podem ser empregados nos programas de IATF (ALVAREZ, 2008;FURTADO, 2011;MELLO et al, 2014).…”