Effect of human chorionic gonadotropin administered at specific times following breeding on milk progesterone and pregnancy in cows

Sianangama, P.C.; Rajamahendran, R.

doi:10.1016/0093-691x(92)90220-l

Cited by 54 publications

(19 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A baixa concentração de P 4 circulante após a cobertura pode ter impacto negativo no desenvolvimento embrionário e reconhecimento materno da gestação (MANN et al, 1999 RAJAMAHENDRAN, 1992;SANTOS et al, 2001;BELTRAN et al, 2003). Diante dessa controvérsia sugere-se a realização de outros experimentos.…”

Section: Resultsunclassified

EFEITO DA ADMINISTRAÇÃO DO HORMÔNIO CORIÔNICO GONADOTRÓFICO (hCG) NA DURAÇÃO DO CICLO ESTRAL E NA TAXA DE PRENHEZ EM BOVINOS DE CORTE

Filho¹,

Kozicki²,

Souza³

2004

AVS

View full text Add to dashboard Cite

RESUMO -Palavras chave: hCG, duração do ciclo estral, fertilidade. ABSTRACT -In the present experiment a total of 62 cows of Charoles and Caracú breeds, artificially inseminated (AI). At day 7th after AI the cows were aleatory distributed in two groups: treated group (n=32) that receive 2.500 UI of human chorionic gonadotropin (hCG) by the intramuscular route and control group (n=30) to wich 1.0 ml of sterile physiological solution was administered also by the intramuscular route. It has been found that the estrous cycle lenght was different (P<0,0001) between the treated and the control groups (24,8 and 21,4 days, respectively). Pregnancy rate did not differ (P>0,05) between treated and the control groups (40,6 and 23,3%, respectively). In this way, the estrous cycle lenght of the treated cows was extended in regard to the control cows. The hCG administration did not increase pregnant rates.Key words: hCG, estrous cycle length, fertility. IntroduçãoApós a inseminação artificial (IA), a mortalidade embrionária (ME) é reconhecida como a maior causa de falhas reprodutivas em bovinos e perdas financeiras significativas para a indústria. A ME refere-se especificamente às perdas decorrentes no período que se estende da fecundação ao completo estágio da diferenciação embrionária que ocorre em torno do 42 o dia (DUNNE et al., 2000). As perdas embrionárias ocorrem antes do 45 o dia de gestação, período que se estende da fertilização até que se conclua a fase de diferenciação. Além disso, a maioria das perdas embrionárias ocorrem durante os primeiros dias após a fertilização e durante o processo de implantação (MAURER e CHENAULT, 1983), que em vacas inicia-se por volta do 22 o dia de gestação (WATHES, 1992).A ME tem sido estimada entre 20 e 40% em vacas (LÒPES-GATIUS et al., 1996) e a morte fetal ao redor de 5% (LAMBERT et al., 1991), podendo exceder a 10% (LÒPES-GATIUS et al., 1996). KASTELIC e GINTHER (1989) observaram que a morte embrionária, quando causada pela lise do corpo lúteo (CL), tem em média como intervalo para a próxima ovulação de 2,4 a 5 dias. Quando a ME é atribuída a problemas com o concepto, o intervalo médio entre a detecção da ME e da ovulação seguinte foi de 20,8 a 35 dias.Em bovinos e em outros mamíferos, o estabelecimento e a manutenção da prenhez depende da contínua secreção de progesterona (P 4 ) pelo CL (BINELLI, 2000). Estudos de

show abstract

Section: Resultsunclassified

EFEITO DA ADMINISTRAÇÃO DO HORMÔNIO CORIÔNICO GONADOTRÓFICO (hCG) NA DURAÇÃO DO CICLO ESTRAL E NA TAXA DE PRENHEZ EM BOVINOS DE CORTE

Filho¹,

Kozicki²,

Souza³

2004

AVS

View full text Add to dashboard Cite

show abstract

“…Embryos dying after Day 16 trigger the maternal recognition of pregnancy mechanism and induce an extension of the estrous cycle with luteal plasma P 4 concentrations on Day 21 (Humblot, 2001). In addition, treatment with hCG per se, may induce an extension of the estrous cycle (Sianangama and Rajamahendran, 1992; Chagas e Silva and Lopes-da-Costa, 2005). Nevertheless, treatment with hCG decreased EEM, thus increasing pregnancy rate on Day 21.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of treatments with hCG and carprofen at embryo transfer in a demi-embryo and recipient virgin heifer model

Torres

Silva

Diniz

et al. 2013

Animal

View full text Add to dashboard Cite

An in vivo model, combining a low developmental competence embryo (demi-embryo) and a high-fertility recipient (virgin dairy heifer) was used to evaluate the effects of treatment with human chorionic gonadotropin (hCG) and carprofen at embryo transfer (ET) on plasma progesterone (P 4 ) concentrations of recipients and on embryonic growth and survival. Embryos were bisected and each demi-embryo was transferred to a recipient on Day 7 of the estrous cycle. At ET, heifers (n 5 163) were randomly allocated to treatment with hCG (2500 IU im), carprofen (500 mg iv), hCG plus carprofen or to untreated controls. Plasma P 4 concentrations were measured on Days 0, 7, 14 and 21 of all recipients plus on Days 28, 42 and 63 of pregnant recipients. Pregnancy was presumed to be present in recipients with luteal plasma P 4 concentrations until Day 21 and confirmed by using transrectal ultrasonography on Days 28, 42 and 63. Embryonic measurements (crown-rump length and width) were obtained on Day 42. Treatment with hCG induced formation of secondary corpora lutea (CL) in 97% of heifers and increased ( P , 0.01) mean plasma P 4 concentrations of non-pregnant recipients on Day 14 and of pregnant heifers on Days 14 to 63. This was associated to a significant decrease in early embryonic mortality. In contrast, subsequent embryonic losses resulted in a non-significant numerical increase by 8% of pregnancies maintained to Day 63. Therefore, treatment with hCG significantly rescued embryos through the maternal recognition of pregnancy window but was not able to support development thereafter. Treatment with carprofen at ET had no significant effects on plasma P 4 concentrations and rate of embryo mortality. Treatment with hCG plus carprofen at ET induced formation of secondary CL in 90% of heifers but decreased the luteotrophic effect of hCG, resulting in no effect on embryo survival. Low developmental competence embryos showed an intrinsic deficiency in overcoming the maternal recognition of pregnancy challenge and in proceeding to further development until Day 28 of pregnancy, whereas mortality beyond this point was residual. Results on pregnancy rates should be confirmed in further experiments involving a larger sample size. Keywords: demi-embryo, hCG, carprofen, progesterone, bovine Implications Embryonic mortality is a major source of economic loss in the cattle industry, and may occur because of intrinsic embryonic, maternal and management factors. These factors may interact, which makes difficult to study their mechanisms of action and the design of appropriate therapeutic approaches. Herein, we used an in vivo model, considering a compromised embryo and a high-fertility recipient, to evaluate therapeutic strategies designed to enhance embryonic survival. Preliminary results showed that treatment with hCG at embryo transfer may be of interest to decrease embryonic mortality, whereas carprofen had no apparent effect on embryo survival. IntroductionPregnancy loss is a major cause of reproductive failure and of economic waste in...

show abstract

“…Significant increase in PR was achieved when hCG was given at Day 5 [72,73] or at day 7 [70,74,75], while hCG significantly increased PR only in some herds when it was given between days 4 and 9 post-AI [76]. In a recent study [77], hCG treatment on day 5 post-TAI could significantly increase PR only in heifers (49.7% vs. 39.5%).…”

Section: Preventive Pharmaceutical Treatment In the Early Luteal Phasmentioning

confidence: 99%

Recent Possibilities for the Diagnosis and Pharmacological Control of Pregnancy Loss in Dairy Cow

Szenci¹

2015

JLS

View full text Add to dashboard Cite

Abstract:One of the most recent techniques for the diagnosis of EP (early pregnancy) in cattle on the farm is B-mode ultrasonography. Under field conditions, acceptable results may be achieved with ultrasonography from days 25 to 30 post-AI. The reliability of the test greatly depends on the frequency of the transducer used, the skill of the examiner, the criterion used for a positive PD (pregnancy diagnosis) and the position of the uterus in the pelvic inlet. Pregnancy protein assays (PAG, PSPB) may provide an alternative method to ultrasonography for determining EP or LEM/EFM (late embryonic/early foetal mortality) in the cow. Although early pregnancy factor is the earliest specific indicator for fertilization, its detection is entirely dependend on the use of the RIT (rosette inhibition test), therefore its use in the field needs further inventions. Preventive pharmaceutical treatments with hCG (human chorionic gonadotropin), GnRH (gonadotropin realising hormone), PRID (progesterone-releasing intravaginal device) or CIDR (controlled internal drug release) inserts at different time periods at or post-AI may have some benefit in decreasing PL (pregnancy loss), however further examinations are warranted to determine how and when these treatments may influence PL in the field.

show abstract

Effect of human chorionic gonadotropin administered at specific times following breeding on milk progesterone and pregnancy in cows

Cited by 54 publications

References 30 publications

EFEITO DA ADMINISTRAÇÃO DO HORMÔNIO CORIÔNICO GONADOTRÓFICO (hCG) NA DURAÇÃO DO CICLO ESTRAL E NA TAXA DE PRENHEZ EM BOVINOS DE CORTE

EFEITO DA ADMINISTRAÇÃO DO HORMÔNIO CORIÔNICO GONADOTRÓFICO (hCG) NA DURAÇÃO DO CICLO ESTRAL E NA TAXA DE PRENHEZ EM BOVINOS DE CORTE

Evaluation of treatments with hCG and carprofen at embryo transfer in a demi-embryo and recipient virgin heifer model

Recent Possibilities for the Diagnosis and Pharmacological Control of Pregnancy Loss in Dairy Cow

Contact Info

Product

Resources

About