Mejora de la eficiencia de la producción ovina

Presentación del Grupo Consolidado A-13 del Instituto Universitario de Investigación Mixto Agroalimentario de Aragón - IA

Preovulatory LH surge of Rasa Aragonesa ewes carrying or not the FecXR allele (ROA®)

La presencia del alelo FecXR en heterocigosis produce un incremento de la tasa de ovulación y prolificidad, así como una mayor respuesta a la eCG. Sin embargo, todavía se desconocen sus posibles efectos sobre la descarga preovulatoria de LH, lo cual es esencial para realizar la inseminación artificial en el momento óptimo. Con este objetivo, se extrajeron muestras sanguíneas a intervalos de 4-6 horas durante las 72 horas siguientes a la retirada de una esponja (FGA, 30 mg), de 50 ovejas adultas agrupadas en 5 lotes en función de su genotipo (R+ y ++; portadoras y no portadoras) y tratamiento hormonal (sin eCG, 240 ó 480 UI). Las concentraciones de LH se analizaron mediante un kit comercial ELISA. No se observó ninguna diferencia significativa en el pico preovulatorio de LH entre ovejas R+ y ++. La eCG adelantó la descarga preovulatoria de LH en ambos genotipos, sin diferencias entre ovejas R+ tratadas con 240 ó 480 UI. Estos resultados demuestran que la presencia de FecXR no afecta al pico preovulatorio de LH, independientemente de la dosis utilizada. Por lo tanto, la dosis de eCG que se aplique a las ovejas R+ estará en función de las necesidades y posibilidades de la explotación para asumir una mayor prolificidad y multiplicidad de partos. En las ovejas ++ tratadas con eCG se recomienda seguir inseminando a las 54 ± 1 horas de retirar las esponjas, como se hace habitualmente, ya que se observó una buena sincronización del pico preovulatorio de LH a las 37 horasThe presence of the FecXR allele in heterozygosity (R+) increases ovulation rate and prolificacy in Rasa Aragonesa ewes, and leads to a greater response to eCG. However, their potential effects on preovulatory LH surge are still unknown, which is essential to establish the optimum time for artificial insemination. With this aim, blood samples were taken at 4-6 hours intervals during 72 hours after the removal of a 30 mg FGA sponge, from 50 adult ewes divided in 5 groups depending on their genotype (R+ and ++; carriers and non-carriers) and hormonal treatment (without eCG, 240 or 480 IU). The LH concentrations were analyzed using a commercial ELISA kit. There was no significant difference on the time of the preovulatory LH surge between R+ and ++ ewes. Treatment with eCG significantly advanced the preovulatory LH discharge in both genotypes, with no difference between R+ ewes treated with 240 or 480 IU. These results demonstrate that the presence of the FecXR allele did not affect the preovulatory LH surge, regardless of eCG dose. Therefore, the dose of eCG that should be applied to R+ ewes could be a decision of the farmer depending on the needs and possibilities of the farm to manage greater prolificacy and multiple births. In ++ ewes treated with eCG it is recommended to continue with the established protocol and inseminate 54 ± 1 hours after sponge withdrawal, as it is usually done, since a good synchronization of the preovulatory LH peak was observed at 37 hoursinseminación artificialprolificidadBMP15eCGraza Rasa aragonesaovulaciónPMSGPublishedPremio Prensa Agraria 2013 otorgado por A.I.D.A

Evaluación de la capacidad de cubrición de los moruecos

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Evaluating the reproductive ability of breeding rams in North-Eastern Spain using clinical examination of the body and external genitalia

Background Predicting the ability of rams to detect, mate and fertilise ewes in oestrus accurately is certainly difficult; however, tests based on clinical examinations have been performed to assess the overall potential capacity of rams to serve and impregnate ewes. Clinical examinations for breeding soundness evaluation were carried out in 897 Rasa Aragonesa (RA) rams from 35 flocks in North-Eastern (NE) Spain. Clinical examinations of head, trunk, limbs and genitals were performed in each ram. Blood samples were collected for a serological study of Brucella ovis. The sheep owners were surveyed regarding the characteristics of the flock, rams’ health history and the management of rams. The clinical alterations found were classified according to severity (mild or severe). Rams were classified as suitable (without lesions or with only mild lesions) or unsuitable (with severe lesions) for breeding depending on the results of the clinical examinations. Results The results showed that 60.6 % of rams presented some type of alteration (mild: 43.3 %; severe: 17.3 %) in various body parts (genitalia: 31.6 %; head and trunk: 37.2 %; limbs: 15.5 %), and that 16.7 % of rams were classified as unsuitable breeders. The most common genital alterations were ulcerative posthitis (18.7 %) followed by testicular lesions (5.3 %). The highest prevalence of unsuitable breeders was found in the category of adult and aged rams (13.8 % and 37.4 %, respectively) and in the category of emaciated rams (33.3 %). All rams examined were seronegative to Brucella ovis. The mean percentage of rams in flocks was 2.8 % (min: 1.6 %; max: 4.6 %); nevertheless, this percentage dropped to 2.5 % (min: 1.4 %; max: 3.7 %) and 2.1 % (min: 0.3 %; max: 3.5 %) when only suitable or effective (suitable mature) rams were considered. Conclusion Thus, it is concluded that there are fewer effective rams in farms than farmers realise. Frequent clinical examination of males is recommended in order to identify potentially infertile rams.Publishe

Elección de las mejores ovejas donantes de embriones mediante la determinación plasmática de su AMH (hormona anti-mülleriana)

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The use of plasma AMH in sheep as an endocrine marker of the ovarian respnse to FSH in MOET programs: abstract

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Desarrollo de un dispositivo intravaginal para la recogida de semen en ganado ovino

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