domingo, dezembro 15, 2013
Garrano. The primitive rebel from the North
Garrano. The primitive rebel from the North
The autochthonous Garrano breed, beyond its relevance in historical and cultural level, is one important reservoir of national genetic variability. Since 1943 a group have lived freely in Peneda-Gerês National Park. A study made from November 2012 to April of 2013 shows that this animals are very parasitized, but they don’t present a concerning inbreeding level. There are good reasons to look to the future of this valuable biologic resource.
One of the species that stands out the most in Peneda-Gerês National Park (PGNP) is the Garrano pony, one of the three Portuguese horse breeds (alongside the Lusitano and the Sorraia). They are small individuals with broad shoulders, a thick neck and abundant manes and fur (Andrade, 1938). They have been in the Iberian Peninsula since the Quaternary period of geological history (Andrade,1938; Oom, 1992; Gomes, 1996). This makes the Garrano the primitive rebel from the North.
During the application process of the Garrano as national heritage, intending to avoid its extinction, a group of students from Colégio Valsassina developed a study on the Garranos of PGNP, from November 2012 to April of 2013.
The results reveal a high level of parasitism, with a 100% level of strongylids prevalence, in fact, these data were already verified by Gomes (1996) in 1994-95, when it was registered a higher average level of eggs per gram of faeces.
Despite the facts, it will be much difficult to reduce the levels of parasitism. On one hand, the animals live freely. On the other hand, many of the used pastures are probably contaminated, which facilitates “recontamination”. Notwithstanding, it’s considered important to develop a monitoring program of parasitism level. In spite of not deworming the animals, the information is always important (Branco and Osório, 2012).
The inbreeding level of the group was studied too, using the Pedigree Viewer program. The data shows that the age average of the population is a little higher than the adult age (6,62 years old) and it seems that there are not problems referring to the inbreeding possibility between individuals. Considering “1” (certain) as the maximum probability of occurrence of an inbreeding situation and “0” (impossibility) as the minimum probability, it was verified a maximum of 0,1875. The modal result was 0. Therefore, it is not foreseeable that this factor would jeopardize the population and the progeny viability of the current generation. However, the low number of individuals could compromise the future of the population, once its variability could become diminished. To avoid this situation, it’s advised a recurrent introduction of new individuals “alien to” the group in order to keep an acceptable level of variability (Oom, 1978).
According to António Rebelo, a technician of the PGNP responsible for the monitoring the Garranos in the field, the current group is only composed by 15 animals. Everything point out a register of an effective population regression in the last years, specifically, comparing with the situation of 1994-96, described by Gomes (1996). However, the fact of existing five males (ally to a low level of inbreeding in the population) could be potential a positive factor for the effective raise of the population in short or medium term.
To Maria do Mar Oom, from Faculty of Science of the University of Lisbon and ambassador of the breed in the application to national heritage, the Garrano, beyond its relevance in historical and cultural level, is one important reservoir of national genetic variability. The developed efforts with the aim of conservation and support of the breeders are fundamental, which ensure a sustained use of this genetic resource from the mountain rural environment of the Portugal North, where they have been since the Paleolithic.
From the legal framework, the national park continues presenting conditions to preserve this important biological resource, integrating genetic, environmental, social and cultural perspective.
Ana Catarina Caçote, Gonçalo Pereira, Joana Duarte. 12º1A
Agradecimentos: Este trabalho não seria possível sem a preciosa colaboração da Doutora Maria do Mar Oom, da Faculdade de Ciências da Universidade de Lisboa e do técnico do Parque Nacional da Peneda-Gerês, António Rebelo, por todo o tempo, ajuda e disponibilidade, essenciais para a realização do nosso projeto. Gostaríamos também de agradecer ao Parque Nacional da Peneda-Gerês pela ajuda disponibilizada.