ABSTRACT
Following the induction of oestrus out of season in small ruminants, low fertility and variations in fertility rates are associated with embryonic losses. One of the main causes of embryonic loss is luteal dysfunction. Gonadotropin Releasing Hormone (GnRH) supports the luteal structure, and increasing progesterone levels may be beneficial in terms of promoting embryonic life. The main objective of the present study was to evaluate the efficacy of GnRH administration following an oestrus induction protocol in the anoestrus season for preventing embryonic loss in goats having failure to conceive during the season. In the study, 106 Damascus goats aged 3-5 years and weighing 45-60 kg were used. The oestrus of 106 goats in the anoestrous group was stimulated with progesterone and pregnant mare serum gonadotropin (PMSG) treatment. Out of breeding season, goats were divided into the 4 following groups: GnRH0 (n = 27), GnRH7 (n = 26), GnRH0+7 (n = 27) and control (n = 26). In each goat, an intravaginal sponge (IS) containing 20 mg of fluorogestone acetate (FGA) was placed into the vagina and left for 9 days. With the withdrawal of the sponge, 550IU PMSG and 125 µg of d-cloprostenol were injected intramuscularly. Oestrus detection was made via teaser bucks for 3 days starting 24 h after withdrawal of the IS. Eighteen bucks known to be fertile were used for breeding. Goats in the oestrus period were mated via natural breeding. The GnRH analogue lecirelin was injected intramuscularly at breeding in the GnRH0 group, on day 7 post-breeding in the GnRH7 group, and both at breeding and on day 7 post-breeding in the GnRH0+7 group. No injections were given to the control group. Blood samples for progesterone measurement were taken by jugular vena puncturing on days 3, 6, 7, 10, 13, 16, and 19 after breeding from 10 randomly chosen goats in all groups. The goats with a level of > 3.5 ng/mL of progesterone on day 21 post-breeding were evaluated as pregnant. Pregnancy was also viewed on day 50 after breeding by real-time ultrasonography (USG) with a 5-7.5 MHz convex probe. The oestrus rate was 96.23% (102/106) in the goats. The rates of onset of oestrus between 36-48 h, 48-60 h and 60 h and beyond were 38.7% (41/106), 21.7% (23/106) and 35.8% (38/106), respectively. The total pregnancy rate was 35.8% (38/106). There were no statistically significant differences (P > 0.05) found for the pregnancy rate, embryonic death rate or progesterone concentration of the groups. However, serum progesterone levels were statistically different in the GnRH7 group compared with the control group (P < 0.05). After synchronisation, various anti-luteolytic strategies can be used to support corpus luteum development and elevate progesterone concentration in the luteal phase to decrease embryonic loss and increase reproductive performance. Therefore, application of GnRH to support the luteal structure and to increase progesterone levels may be beneficial in terms of supporting embryonic life. The results showed that GnRH treatment on the day 7 post-breeding following oestrus induction, including FGA and PMSG, can increase serum progesterone levels in Damascus goats in the anoestrus period. However, following oestrus induction in the anoestrus period, it was seen that GnRH treatment at breeding or on day 7 after breeding did not have any positive effect on embryonic loss or reproductive performance. In conclusion, it was considered that this protocol could be implemented successfully, yielding a 35% pregnancy rate in Damascus goats in the anoestrus period, but embryonic loss must be deeply studied in detail.(AU)
Subject(s)
Animals , Female , Anestrus , Estrus/drug effects , Goat Diseases/embryology , Embryo Loss/veterinary , Gonadotropins/administration & dosage , GoatsABSTRACT
Estudou-se o efeito da idade sobre a fertilidade de éguas inseminadas com sêmen asinino diluído, resfriado e armazenado. Os ciclos foram acompanhados por palpação transretal e rufiação, sendo as inseminações realizadas às terças, quintas e sábados, a partir da detecção de um folículo de 3,0 a 3,5cm de diâmetro, em um dos ovários, até a ovulação. O sêmen de cinco jumentos da raça Pêga foi diluído nos diluidores de leite em pó desnatado-glicose ou glicina-gema de ovo, resfriado a 5ºC e armazenado por 12 horas, sendo a dose inseminante de 400 x 106 espermatozoides móveis (no momento da diluição final, pré-resfriamento). Os resultados de 195 ciclos estrais, referentes a 141 éguas, foram agrupados em classes, de acordo com a idade das éguas: 2,5 a 6 anos, 6,5 a 10 anos, 10,5 a 14 anos e 14,5 a 19 anos. As taxas de concepção, ao primeiro ciclo, foram de 68,42%, 50,75%, 46,88% e 52,17% e, após quatro ciclos, de 69,57%, 47,92%, 46,34% e 45,71% para as faixas etárias de 2,5 a 6, 6,5 a 10, 10,5 a 14 e 14,5 a 19 anos, respectivamente (P>0,05). A idade não teve efeito sobre a fertilidade das éguas inseminadas com sêmen asinino diluído e resfriado...
The effect of the mare age on fertility of mares inseminated with diluted, cooled and stored jackass semen was studied. The females were controlled by transrectal palpation and teasing, and inseminated every Tuesday, Thursday and Saturday, since the detection of a 3.0 to 3.5cm follicle diameter, in one of the ovaries, until ovulation. The semen of five Pêga jackasses was diluted in skim milk-glucose or in egg yolk-glicine extender and cooled at 5ºC for 12 hours, with the inseminate dose of 400 x 106 motile spermatozoa (at the moment of the final dilution, before cooling). The results of 195 cycles of 141 mares were grouped, in accordance with the age: 2.5 to 6 years, 6.5 to 10 years, 10.5 to 14 years and 14.5 to 19 years. The pregnancy rates for the first cycle were 68.42%, 50.75%, 46.88% and 52.17%, and after four cycles, the pregnancy rates/cycle were 69.57%, 47.92%, 46.34% and 45.71%, respectively for 2.5 to 6, 6.5 to 10, 10.5 to 14 and 14.5 to 19 years (P>0,05). The mare age had no influence on fertility, using diluted and cooled jackass semen...
Subject(s)
Animals , Age Factors , Equidae/embryology , Fertility Agents , Embryo Loss/veterinary , Insemination, Artificial/veterinary , SemenABSTRACT
A análise morfológica da casca do ovo da avestruz é importante, pois diversos fatores morfológicos podem estar relacionados com a eclodibilidade do ovo desta espécie no Brasil. Para tanto foram analisadas 60 amostras de ovos aparentemente normais (ovos eclodidos e com morte embrionária). Foram efetuadas observações que permitiram estabelecer: a espessura média da casca do ovo, a porosidade da casca destes ovos, e correlacionar estas variáveis com a eclodibilidade. Os resultados foram analisados estatisticamente mediante o teste de Duncan, o que mostrou que ovos com menor porosidade tem também uma menor eclodibilidade. A porosidade média dos ovos eclodidos é de 19,87 poros/cm², e dos ovos com morte embrionária é de 16,78 poros/cm². Não houve diferença estatística entre a espessura da casca nas regiões estudada, nem interação entre viabilidade e as regiões.
Morphological analysis of the ostrich eggshell is important because several factors can be related to morphological hatchability of eggs of this species in Brazil. Therefore, 60 samples of apparently normal eggs were analyzed (eggs hatched and with embryonic death). The observations were allowed to establish that: the average thickness of the eggshell, the porosity of the shell of the eggs, and correlate these variables with hatchability. The results were statistically analyzed by Duncan's test, which showed that eggs with less porosity also have a lower hatchability. The average porosity of hatched eggs is 19.87 pores/cm², and of eggs with embryonic death is pores/cm2 16.78. There was no statistical difference between the thickness of the shell in the regions studied, no interaction between viability and the regions studied.
Subject(s)
Animals , Egg Shell/anatomy & histology , Struthioniformes , Biometry , Embryo Loss/veterinaryABSTRACT
Visando esclarecer o mecanismo da açäo embriotóxica do barbatimäo, pesquisaram-se os efeitos da administraçäo de sementes de barbatimäo sobre as principais glândulas endócrinas de ratas grávidas. Encontrou-se diminuiçäo do peso dos ovários e do peso e medidas dos corpos lúteos gravídicos no grupo tratado. Numa segunda etapa, foi feita administraçäo de progesterona em ratas tratadas com sementes de barbatimäo. Näo houve alteraçäo dos índices de reabsorçäo dos embriöes, que permaneceram elevados, indicando que o efeito embriotóxico näo seria devido à déficit dos níveis de progesterona. Propöe-se que o efeito do barbatimäo seja através de alteraçöes da zona basal da placenta, acarretando a morte embrionária e atrofia do corpo lúteo