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
Determining if reproductive failures in ewes at the semiarid region in the state of Bahia are related to the consumption of the species Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, and this study was developed using pregnant ewes divided into six groups: G1, G2, G3, G4 with six animals each, G5 and G6 with ten animals. Each group received fence leaves in the proportion of 1%, 2%, 0.5%, and 0.25% of live weight (LW) respectively; G5 and G6, with ten animals each, receiving 0.25% and 0.5% of the LW, respectively, and the Control Group, comprising 16 ewes, were grass feeding (Cynodon dactylon). Ewes from G1 to G4 were the same, except for two, and started ingestion of the plant four days after ending of natural mating on the 80th day of gestation, while those regarding from G5 to G6 groups started ingestion on the 26th day of gestation ending on the 98 day. The ultrasonographic test was performed weekly. In G1 ewes (1%), there was an embryonic loss on the 32nd and 39th days of gestation and abortion on the 46th day. In G2 (2%), the embryo loss was earlier (on the 26th day of gestation), and abortion on the 46th day of gestation. In G3 group (0.5%), there was an embryonic loss around the 40th day of gestation. In G4 group (0.25%), it was observed the occurrence of one death lamb with bone malformations. In G6 (0.5%), abortion occurred later (108 days), followed by retained placenta. This was also verified in G5 group (0.25%). The presence of fetal malformation was found in death lambs born in G4 group, born alive from G5 and G6 groups, and one aborted from G6. In G5 and G6 groups, there were also genetic alterations on surviving lambs. In addition to these results, recurrent estrus was observed without gestation in G1, G2, G3, and G4 ewes. From the Control Group, 13 normal lambs were born without genetic alterations; furthermore, concerning a quadruple birth, three lambs were born dead. The results infer that species of C. pyramidale in low doses causes reproductive losses in pregnant ewes, therefore it is not recommended for sheep diet over the first 60 days of gestation.(AU)
Para determinar se falhas reprodutivas em ovelhas na região semiárida da Bahia estão relacionadas ao consumo de Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, foi realizado um estudo utilizando-se ovelhas prenhes divididas em seis grupos e dois Grupos Controle. Os grupos G1, G2, G3 e G4 com seis animais cada. Cada grupo recebeu folhas fenadas na proporção de 1%, 2%, 0,5% e 0,25% do peso vivo (PV) respectivamente; G5 e G6, com 10 animais cada, que receberam 0,25% e 0,5% do PV respectivamente. Os Grupos Controle foram alimentados com ração e capim (Cynodon dactylon). Ovelhas dos grupos 1 a 4 iniciaram ingestão da planta quatro dias após monta natural com término aos 80 dias de gestação, enquanto as dos grupos 5 a 6 iniciaram ingestão no 26º dia de gestação com término aos 98 dias. Avaliação ultrassonográfica foi realizada semanalmente. Nos animais do G1 (1%), verificou-se perda embrionária aos 32 e 39 dias de gestação, e aborto aos 46 dias. Nos do G2 (2%) a perda embrionária foi mais precoce (26 dias), e aborto aos 46 dias. No G3 (0,5%), houve perda embrionária em torno dos 40 dias. No G4 (0,25%), verificou-se ocorrência de natimorto com malformações aos 150 dias de gestação. No G6 (0,5%) o aborto ocorreu mais tardiamente (108 dias), seguido de retenção de placenta. Essa ocorrência também foi verificada no G5 (0,25%). A presença de malformação fetal foi encontrada em fetos natimorto do G4, nascidos vivos do G5 e G6, e um abortado do G6. No G5 e G6 também foram observadas alterações de aprumos em cordeiros sobreviventes. Do Grupo Controle nasceram 13 borregos normais, porém uma ovelha apresentou gestação quádrupla com três natimortos. Os resultados inferem que C. pyramidale fenada em baixas doses causa perdas reprodutivas em ovelhas gestantes, não sendo por isso recomendada para a dieta de ovelhas durante os primeiros 60 dias de gestação.(AU)
Subject(s)
Animals , Female , Pregnancy , Plant Poisoning/veterinary , Teratogens , Abortion, Veterinary/etiology , Sheep, Domestic/abnormalities , Embryo Loss/etiology , Fabaceae/poisoningABSTRACT
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...