Fattori che influenzano la competenza allo sviluppo di embrioni di bufalo e bovino prodotti  in vitro

Responsabili di progetto

Flavia Pizzi, Ahmed Sabry Abdoon

Accordo

EGITTO - ASRT - Academy of Scientific Research and Technology

Bando

CNR/ASRT 2011-2012

Dipartimento

Agroalimentare

Area tematica

Scienze bio-agroalimentari

Stato del progetto

Nuovo

Proposta di ricerca

Buffalo and cattle are indispensable livestock resources to millions of small holder farmers in the Mediterranean area. Infertility is one of the major critical factors affecting biological and financial performance of animal production systems and genetic improvement of livestock. Many reasons were account for infertility in buffalo and cattle, but the most important component seems to be the anestrous (inactive ovary) silent heat (subestrous) or a reduction in fertilization and embryonic survival rates (low conception rate).
The low summer fertility of about 60% of the world dairy cattle and buffalo populations is associated with high ambient temperatures. These include poor estrous expression, distinct seasonal reproductive patterns, and decreased conception rate leading to prolonged inter-calving intervals. However, the direct effects of hyperthermia on specific reproductive functions have not been clearly explored particularly at the molecular level in buffalo.
The present project aims to identify genetic factors that cause anestrous or low fertilization and early embryonic death, which is the first step in eliminating these problems from the population and thereby would enable reduction in the frequency of the deleterious alleles at these loci by marker- or gene-assisted selection, preventing further decline or even improving reproductive status of buffalo and cattle.
Moreover, artificial insemination is considered as one of the most modern techniques used in developed countries for the genetic improvement of livestock productivity The technology relies on artificial insemination of frozen semen from bulls with high genetic and productive potentials  and the spread of these potentials through artificial insemination of frozen semen in livestock breeding. In Egypt, during the last decades, the technology of artificial insemination did not take the adequate attention to ensure the characteristics and genetic potentials of the sires used in the programs of artificial insemination for both buffalo or cows and then there was no significant impact of the programs of artificial insemination in improving the productivity of milk or meat production or growth rate or even improve fertility for buffalo or cattle.
With the difficulty of access to accurate records either for buffalo or cattle, to choose breeding bulls used for artificial insemination, this project depends on the selection of breeding bulls used in the centers of artificial insemination according to the genetic markers through the identification of some of the genes associated with fertility and productivity and diseases resistance in order to use their frozen semen in artificial insemination programs, and thereby increase the fertility and productivity and disease resistance at the national level. This project  can be applied to young bulls, which can be selected for breeding programs. 
The project also aims to identify the effect of heat stress and of the addition of some antioxidants in diluents on the viability and fertilizing capacity of fresh and frozen semen in buffalo and cattle.
In conclusion annual economic losses could be partially alleviated by improving fertility after heat stress through genetic selection of highly fertile sires and dams.

Obiettivi della ricerca

The overall objectives of the present project are to identify genes relative to infertility in buffalo and cattle exposed to heat stress. Also, to illustrate genes regulating fertility in buffalo and cattle bulls used under AI programs. This research will explore a new basic scientific knowledge that will be applied to improve animal reproduction and production.
Specific objectives

To identify changes in gene expression pattern’s in relation to reproductive status  in buffalo and cattle.
To explore the direct effect of season  on gene expression in granulose and theca interna cells of preovulatory follicles in buffalo and cattle ovaries.
To investigate the patterns of gene expression  in cumulus-oocyte-complexes recovered from small, medium and large size ovarian follicles during summer vs. winter season in buffalo.
To demonstrate the direct effect of heat stress on patterns of mRNA expression during in vitro maturation of buffalo and cattle oocytes and in relation to the subsequent embryo development.
To study the effect of supplementation of maturation, fertilization or culture media with antioxidant on the developmental competence and gene expression pattern’s of buffalo and cattle oocytes and embryos.
To compare in vitro assessment of semen quality during cold and hot season with conception rate
To clarify genes relative to bull fertility in buffalo and cattle
To evaluate the effect of addition of antioxidants on viability and freezing capacity of semen exposed to heat stress

Ultimo aggiornamento: 14/05/2025