The animal article of the month for August is “Factors of importance when selecting sows as embryo donors”.

An adequate selection of embryo donors is a key point of and efficient embryo transfer (ET) program. In pigs, embryo donor selection is commonly based on genetic value, good body condition, high health status and an optimal breeding history. However, we should consider other individual factors, such as the parity, which can play an important role in the total efficiency of embryo production and consequently in the overall effectiveness of ET.

In our study we demonstrated that not only parity (from 2 to 7) does not influence the reproductive parameters of donor sows (in terms of pregnancy rate, ovulatory response, fertilization rate and percentages of viable and transferable embryos) but also the results from our experiments also confirm that season (fall to spring) and weaning-estrus interval (WEI: 3-4 days) do not affect these reproductive variables. This means that there is a possibility of using donor sows with a wide range of parity and during a wide period of time, which facilities the application of the ET programs in the donor farms. The reasons why we had only selected multiparous sows are the high accessibility on farms and because they usually have a greater ovulation rate than gilts and primiparous sows. On the other hand, we only selected donor sows with a WEI of 3 or 4 days because more than 80% of the superovulated sows start the estrus within that period. Finally, we discarded summer season because it is already recognized that high ambient temperature adversely affects the outcome of embryo collection and increases the risk of mortality during and shortly after surgery.

Our future direction is to establish a practical and efficient method for non-surgical transfer of short-term (in liquid state) and long-term (cryopreserved) stored embryos in pigs. The final goal of the program is to facilitate the movement and introduction of genetic material (i.e., embryos) into a herd with reduced transportation cost, absence of an effect on animal welfare during transportation and minimal risk for disease transmission.

This article is freely available for one month:

“Factors of importance when selecting sows as embryo donors”.

Authors: A. Nohalez, C. A. Martinez, J. Reixach, M. Diaz, J. Vila, I. Colina, I. Parrilla, J. L. Vazquez, J. Roca, M. A. Gil, H. Rodriguez-Martinez, E. A. Martinez and C. Cuello

The animal Article of the Month is selected by the Editor-in-Chief and is freely available for one month. View the recent selections

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