Publication Date:
2006
abstract:
Genetic improvement is generally associated to large breeds and management of local small breeds
is seen as maintenance of the current genetic profùe, however, selection programmes may increase
sustainability oflocal breeds. The paper discusses some issues associated to selection in local breeds.
First, in generai farm animal populations are under some mass selection: in these cases the commonly
used formula of S. Wright to compute effective size is inappropriate and its use results in considerably
lower estimates of inbreeding rates. Secondly, research has been developed in the last years to
design breeding schemes which maximise genetic gain while lirnitingthe rate of inbreeding. Although
these investigations generally refer to intensively selected nuclei, they set a useful framework for
selection in local breeds of small size, but its implementation needs further research. As an example
it is shown that index selection adjusted for average relationship can produce appreciable genetic
progress in a breed as small as 750 cows with acceptable inbreeding increments: compared to the
Italian Friesian, expected response per year was 0.29,0.27 and 0.29 respectively for rnilk kg, fat kg
and protein kg. Thirdly, which traits should be considered? It is suggested that genetic improvement
should maintain ali characteristicscontributing to low production costs, the environrnental and cultural
values of their farming systems and the links between breeds and their farming areas, that can add
value to their products within the European certification system~of agricultural products.
Iris type:
02.01 Contributo in volume (Capitolo o Saggio)
Keywords:
seleetion; inbreeding; loeal breeds; eonservation; animaI genetie resourees.
List of contributors:
Pizzi, Flavia
Book title:
Animal Products from the Mediterranean area