The effect of LH concentration in a porcine pituitary extract and season on superovulatory response of Bos indicus heifers

Tríbulo, H.; Bó, G. A.; Jofre, F.; Carcedo, J.; Alonso, A.; Mapletoft, R.J.

doi:10.1016/0093-691x(91)90262-c

Cited by 11 publications

(7 citation statements)

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“…containing 100%, 16% or 2% LH (Pure FSH), Tribulo et al [42] reported that the more purified preparations caused the higher superovulatory response (Tab. II).…”

Section: Gonadotrophins and Superovulationmentioning

confidence: 99%

Recent advances in the superovulation in cattle

Steward²,

2002

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mercial embryo transfer records. In a report of 2048 beef donor collections, a mean of 11.5 ova/embryos with 6.2 transferable embryos were collected from each cow [27]. However, the variability was great in both the superovulatory response and embryo quality; 24% of the collections did not produce viable embryos, 64% produced fewer INTRODUCTIONThe objective of superstimulatory treatments in the cow is to obtain a maximum number of fertilized and transferable embryos with a high probability of producing pregnancies [6]. Wide ranges in superovulatory response and embryo yield have been detailed in several reviews of com- Abstract -The variability in the superovulatory response continues to be one of the most frustrating problems with embryo transfer in cattle. The removal of LH from pituitary extracts has tended to reduce the variability in response, and several studies involving the use of the purified porcine pituitary extract, Folltropin ® -V are reviewed. The major source of variability in the superovulatory response in cattle is the status of ovarian follicles at the time of initiation of gonadotrophin treatments. Data support the benefits of initiating gonadotrophin treatments at the time of emergence of a follicular wave. Incorporation of techniques designed to control follicular wave dynamics, such as follicular ablation, or treatment with estradiol/progesterone, have reduced the variability caused by treating cows at different stages of follicular development, and at the same time improved response by taking advantage of endogenous recruitment and selection mechanisms. New protocols offer the convenience of being able to initiate gonadotrophin treatments quickly and at a self-appointed time, without the necessity of estrus detection and without sacrificing response. Methods can be used for repeated superstimulation of donor animals at 25 to 30 day intervals, without regard to estrus detection or stage of the estrous cycle, and without compromising embryo production. superstimulation / gonadotrophin / FSH / LH / follicular waves / embryo transfer / cattle Reprod. Nutr. Dev. 42 (2002) [601][602][603][604][605][606][607][608][609][610][611] 601 Communication

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“…containing 100%, 16% or 2% LH (Pure FSH), Tribulo et al [42] reported that the more purified preparations caused the higher superovulatory response (Tab. II).…”

Section: Gonadotrophins and Superovulationmentioning

confidence: 99%

Recent advances in the superovulation in cattle

Steward²,

2002

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“…The more important question is the possible biological effect of the so called FSH/LH ratio. Donaldson et al [19], Beckers [3], Chupin et al [11], Gonzales et al [24], Tribulo et al [67], and Yamamoto et al [79] showed that FSH products with reduced LH content give higher ovulation number, fertilisation rate and embryo quality. It is speculated [29] that "high" LH activities cause luteinisation of follicles, receptor down regulation and premature ovulations.…”

Section: Bioactivity Of Fsh Productsmentioning

confidence: 99%

Superovulation in cattle: practical aspects of gonadotropin treatment and insemination

et al. 2002

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]. Kanitz et al. [32] showed for FSH that with increasing doses the number of ovulations increases significantly until a plateau was reached for the parameter. It was not possible to increase ovulation number DOSE-RESPONSE RELATIONSThe ovulation number and the following number of recovered oocytes and embryos show a dose-dependent pattern. This was partly or fully shown for hMG [47] Abstract -Embryo transfer (ET) in cattle has been used for the realisation of breeding programmes world-wide for more than 20 years. The efficiency of breeding technology, i.e. the breeding progress and costs, depends to a large extent on the results of superovulatory treatment and artificial insemination (A.I.). The results of this step are characterised by a high degree of variation. Numerous attempts have been undertaken to explain the reason(s) for this. Numerous attempts have also been made to clarify the importance of different factors affecting the results. Undoubtedly, the applied hormones and the scheme of insemination itself are main factors, which influence the number and the portion of transferable embryos. Therefore this paper is focused on the following aspects of superovulatory treatment with FSH: dose-response relations, bioactivity of the glycoprotein, FSH/LH ratio, ovulation time and time-oriented insemination, frequency of gonadotropin administration and follicular population at the time of gonadotropin application.cattle / superovulation / FSH / follicles / ovulation / time-oriented insemination Reprod. Nutr. Dev. 42 (2002) 587-599 587

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“…With regard to the superovulatory response to twicedaily administration, the FSH-to-LH ratio appears to be an important factor, as it has been shown that a high degree of LH contamination reduces the superovulatory response [36], fertilization rate, and embryo quality [37,38], and that a large bolus dose of FSH, even if highly purified, yields a high serum LH concentration and a reduced superovulatory response [22]. In our present study, we used Antrin-R10, which is a refined FSH preparation (containing 0.85% LH), thereby allowing a superovulatory response to be induced by a single sc administration of pFSH comparable with that obtained by multiple administration, suggesting that 20 to 30 AU might be the optimal dose in Japanese Black cows.…”

Section: Discussionmentioning

confidence: 97%