RésuméAs a tropical country, Colombia has an important potential for ovine production; a sheep population of around one million animals is raised without or with very poor technical support and knowledge. There is a sort of management followed by tradition from one generation to another and it could be said that is ancestral. During recent years technical support has begun to be implemented but it is in a small part of the farms. There are some native breeds and the others foreign adapted whose ancestors arrived many years ago, like the first Corriedale, coming from Australia or Romney Marsh and Hampshire imported from Great Britain. Recently new breeds have been imported from different countries, including wool and meat breeds. There are some associations with around one thousand breeders as registered partners; most of them are considered as small breeders, because they have less than ten animals in total.
The geographical location of Colombia classifies it as a non-seasonal equatorial tropical country not affected by a seasonal regime; in general two types of climatic periods, dry and rainy periods affect the region (Andina) where this study was performed. The geographical distribution of two types of sheep depends on temperature: wool sheep are found at high altitudes and low temperatures and hair sheep are found at lower altitude and with an average temperature that is considerably higher.
Appropriate knowledge about reproduction physiology could be a clue to trigger the development of production of meat and wool sheep in high and low altitude regions. Knowing exactly how the most frequently used breeds, adapted foreign and native, behave under particular environmental conditions absence of seasonality, are part of the knowledge useful to improve ovine production.
The research presented here is part of a North-South cooperation project between the University of Namur (Belgium) and the National University of Colombia (site of Bogota). The project aims at improving knowledge about reproductive aspects of sheep production in the high altitude regions of Colombia; first by developing a sheep investigation center under the direction of the National University of Bogota and secondly by performing field investigations in pilot farms. This doctoral thesis aims at characterizing reproduction physiology in young and adult sheep of four wool breeds, one native and three foreign adapted, raised under high altitude conditions.
|la date de réponse
|28 avr. 2015
|Nathalie Kirschvink (Promoteur), Benoit Muylkens (Président), Robert Mandiki (Jury), Martine Raes (Jury), Henry Grajales-Lombana (Jury), Mouâd Chentouf (Jury), Christian Hanzen (Jury), Jean-François Beckers (Jury) & Isabelle Donnay (Jury)