Conception rates of dairy cows following early not-pregnant diagnosis by ultrasonography and subsequent treatments with shortened Ovsynch protocol

Stevenson, Jeffrey S.; Cartmill, J. A.; Hensley, B.A.; El-Zarkouny, S. Z.

doi:10.1016/s0093-691x(03)00042-6

Cited by 43 publications

(33 citation statements)

References 16 publications

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“…At first, the Resynch program (so called traditional Resynch) was initiated at pregnancy diagnosis around 28 to 32 days after TAI ( Stevenson et al, 2003;Marques et al, 2012Marques et al, , 2015. Cows diagnosed as nonpregnant immediately initiated a new protocol for TAI.…”

Section: Resynchronization Of Ovulation (Resynch Programs)mentioning

confidence: 99%

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Baruselli¹,

Ferreira²,

Colli³

et al. 2017

Anim Reprod

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Beef and dairy productivity depends directly on the reproductive efficiency and genetic gain of the herd, which can be related to the appropriate use of biotechnologies, such as timed artificial insemination (TAI). When considering variations in synchronizations protocols, longer or shorter periods of progesterone (P4) device treatment could provide benefits to fertility. However, our studies evidenced that protocols with six (J-synch), seven, eight and nine days of P4 device treatment had similar pregnancy per AI (P/AI). In cyclic cows, the early prostaglandin (PGF) administration, moving from the day of P4 device removal to two days earlier, which results in four handlings of cows, or the administration of one extra dose of PGF at the onset of the protocol and a single PGF on the day of P4 device removal (three handlings) are both efficient to induce early luteolysis, reducing serum P4 concentrations and, therefore, stimulating LH pulsatility, which improves growth of the dominant follicle and results greater P/AI when compared with protocols with the administration of PGF only on the day of P4 device removal. Resynchronization is another valuable tool to reduce the interval between AI. Traditional Resynch is initiated at pregnancy diagnosis (28 to 32 days after TAI) and the interval between AI is around 40 days; Resynch 22 and Resynch 14 respectively initiates 22 and 14 days after the previous AI in all cows (unknown status of pregnancy) and reduces the interval between AI to 32 and 24 days. The novelty about Resynch 14 is the need to use of Doppler ultrasonography for pregnancy diagnosis [evaluation of corpus luteum (CL) vascularization]. Similar P/AI after Resynch 22 and 14 were found in Nelore cows. In dairy cattle, reproductive management is carried out throughout the year, thus, it is important to adapt the reproductive management to few established days of the week. Therefore, traditional Resynch and Resynch 25 were set to start 32 and 25 days after previous TAI, respectively. The hastening of reproductive age of Nelore heifers aims to reduce age at first calving and increase productivity. Factors such as age, weight, body condition score (BCS), uterine score (USC), average daily weight gain (ADG), withers height/depth of rib relationship (dRIB) and subcutaneous fat thickness (SCFT) were associated with an increase in the success of gestational establishment at TAI and can be used to select the heifers that are more suitable for reproduction. These technologies can contribute to improve the national production of kilograms of meat and liters of milk per hectare, and consequently improve livestock profitability.

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Section: Resynchronization Of Ovulation (Resynch Programs)mentioning

confidence: 99%

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Baruselli¹,

Ferreira²,

Colli³

et al. 2017

Anim Reprod

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“…Pregnancy can be accurately diagnosed from day 29 in cattle (Stevenson et al, 2003) and from day 20 in sheep (Romano and Christians, 2008). However, ultrasonography requires the use of appropriate equipment by a skilled operator.…”

Section: Introductionmentioning

confidence: 99%

Interferon stimulated genes as peripheral diagnostic markers of early pregnancy in sheep: a critical assessment

Mauffré

Grimard

Eozénou

et al. 2016

Animal

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We investigated the diagnostic reliability of pregnancy detection using changes in interferon stimulated gene (ISG) messenger RNA (mRNA) levels in circulating immune cells in ewes. Two different groups of ewes (an experimental group, experiment 1 and a farm group, experiment 2) were oestrus-synchronized and blood sampled on day 14 (D0 = day of insemination in control animals, experiment 1) and day 15 (experiment 2). Real-time PCR were performed to evaluate the abundance of different ISG mRNAs. In the experimental group, peripheral blood mononuclear cells of 29 ewes born and bred in experimental facilities were isolated using a Percoll gradient method. Gene expression for Chemokine (C-X-C motif) ligand 10 ( CXCL10), Myxovirus (influenza virus) resistance 1 ( MX1) and Signal transducer and activator of transcription 1 (STAT1) mRNA were, respectively, 8.3-fold, 6.1-fold and 2.7-fold higher ( P < 0.001) in pregnant compared with non-pregnant ewes. The receiver operating characteristic (ROC) curves generated from the real-time PCR data demonstrated that a reliable cut-off could be established for CXCL10, MX1 and STAT1. In the farm group of animals, peripheral blood leucocytes of 37 cross-bred multiparous ewes bought from several herds were isolated using the PAXgene ® procedure. This blood sampling procedure is achievable in farms, whereas the Percoll method is not. No significant differences ( P > 0.10) in CXCL10, STAT1, MX1, Myxovirus (influenza virus) resistance 2 ( MX2) and ISG15 ubiquitin-like modifier ( ISG15) mRNA expression were found between pregnant and non-pregnant ewes. The ROC curves and the hierarchical classification generated from the real-time PCR data failed to discriminate between pregnant and non-pregnant animals. In this group of animals, our results show a strong variability in ISG expression patterns: 17% of animals identified as non-pregnant by the five tests were in fact pregnant, only 52% of pregnant animals had at least two positive results (two genes above threshold), whereas up to five positive results (five genes above threshold) were needed to avoid misclassification. In conclusion, this study illustrates the high variability in ISG expression levels in immune circulating cells during early pregnancy and, therefore, highlights the limits of using ISG expression levels in blood samples, collected on PAXgene ® tubes on farms, for early pregnancy detection in sheep.Keywords: interferon stimulated genes, pregnancy diagnosis, early pregnancy, implantation, sheep ImplicationsThis study aimed to investigate the accuracy of gene transcript quantification in blood (interferon stimulated genes (ISG)) as a method of early pregnancy diagnosis in sheep. This method of pregnancy detection is based on a single blood sample, whereas routine pregnancy diagnosis, namely ultrasonography, requires specific equipment and a skilled operator. Our results show a higher variability in ISG expression patterns in animals from commercial herds than from a controlled research station. Consequently, this prevents th...

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“…Protocols for resynchronization of estrus that considered the stage of the estrous cycle have been applied after detection of non-pregnant cows by per rectum palpation of the uterus and assignment of protocols based on the presence or absence of a CL [1]. Another approach for resynchronization after non-pregnancy diagnosis by ultrasonography was either to initiate the Ovsynch protocol 7 days before ultrasonography or to take advantage of a natural resynchronization after previous service with application of shortened protocols that used PGF 2a to induce luteolysis and then GnRH [29] or ECP [3] to induce ovulation. An alternative is to consider the stage of the estrous cycle at the time of initiation of the resynchronization protocol by evaluating ovarian structures and uterine characteristics at the time of a nonpregnancy diagnosis.…”

Section: Introductionmentioning

confidence: 99%

Reproductive parameters in Holstein dairy cows treated with three resynchronization methods

Kor¹

2012

IOSJPBS

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Conception rates of dairy cows following early not-pregnant diagnosis by ultrasonography and subsequent treatments with shortened Ovsynch protocol

Cited by 43 publications

References 16 publications

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Timed artificial insemination: current challenges and recent advances in reproductive efficiency in beef and dairy herds in Brazil

Interferon stimulated genes as peripheral diagnostic markers of early pregnancy in sheep: a critical assessment

Reproductive parameters in Holstein dairy cows treated with three resynchronization methods

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