Examinando por Autor "Ugarte, G."

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    Design of a village breeding programme for a llama population in the High Andes of Bolivia
    (2007-09-07) Wurzinger, M.; Willam, A.; Delgado, Javier; Nürnberg, Michaela; Zárate, A.V.; Stemmer, Angelika; Ugarte, G.; Sölkner, J.
    No national breeding programme for llamas is in place in Bolivia. Initiatives for genetic improvement are rarely found and are usually carried out by NGOs working in rural development or improvement of livestock production or research stations. Farmers in the Province of Ayopaya in the District of Cochabamba have formed a breeders’ organization with the aim of improving fibre production. In this study, a detailed outline of a breeding programme with a focus on organizational and technical details is described. Facing constraints like illiteracy of farmers, bad infrastructure and lack of finances, a simple breeding programme is set up. The breeding goal is a higher fleece weight while keeping the fleece quality at the current high level. Greasy fleece weight and fibre diameter are identified as main selection criteria. Mass selection of males is carried out. Selected males are either exchanged between farmers and used in the herds or are kept during the mating season in a central mating station owned by the breeders’ organization. Model calculations were carried out with the program zplan, which is based on a deterministic approach. zplan evaluates the genetic and economic efficiency of breeding strategies considering one cycle of selection. Scenarios with only intra-herd use, using only the central mating station or combinations of those were compared in terms of expected genetic gain and expected increase of inbreeding. Fastest genetic progress is achieved when the males are kept in a central mating station as the selection intensity is on a high level. Rates of inbreeding vary between 0.08 and 0.32% per generation.
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    Genetic and non-genetic factors influencing fibre quality of Bolivian llamas
    (2005-08-26) Wurzinger, M.; Delgado, Javier; Nürnberg, Michaela; Valle Zárate, Anne; Stemmer, Angelika; Ugarte, G.; Sölkner, J.
    Fibre samples of 2378 llamas were analysed with the optical fibre diameter analyser (OFDA). The following traits were considered: mean fibre diameter (MFD), standard deviation (S.D.), diameter of fibre <30um (DF < 30), proportion fibre <30um (%F < 30), proportion of kemp (PK) and proportion of medullated fibre (PMF). The effects of type of llama, age, sex and coat colour were studied. The type of llama influenced all traits showing that Th’ampulli (fibre type) is better than Kh’ara (meat type).With increasing age of the animal MFD, S.D., DF < 30 and PK increased whereas %F < 30 decreased. Comparing the two sexes, females showed better fibre quality. Heritabilities and genetic correlations for fibre traits were estimated using animal model procedures where all information came from mother–offspring relationships. Heritability estimates were 0.33, 0.28, 0.36, 0.32 and 0.25 for MFD, S.D., DF < 30, %F < 30 and PK, indicating potential for genetic selection. Genetic correlations between fibre traits and some body measurements were also calculated. In conclusion, the llama population studied shows a high genetic potential for high quality fibre production. The information available allows further steps towards the design of a breeding program.
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    Growth curves and genetic parameters for growth traits in Bolivian llamas
    (2004-12-04) Wurzinger, M.; Delgado, Javier ; Nürnberg, Michaela; Valle Zárate, Anne; Stemmer, Angelika; Ugarte, G.; Sölkner, J.
    The present study was carried out in the High Andes of the Department Cochabamba, Bolivia. Two types of llamas were found in the study area: Th’ampullis with higher fleece yields and fitting a fibre type; Kh’aras used as pack animals and fitting a meat-type. Growth curves for height at withers (HW), body length (BL), chest circumference (CC), abdomen circumference (AC) and body weight (BW) were described with the non-linear Brody function. The differences between sexes or types, except in the case of BW, were small. Equations for predicting body weight from different body measurements that could be easily obtained under field conditions were calculated. Reasonable fits were obtained with the inclusion of chest circumference and body length or chest circumference alone. Heritabilities and genetic correlations were estimated using animal model procedures based on mother–offspring relationships. Heritabilitiy estimates were 0.36, 0.27, 0.15, 0.09 and 0.11 for BW, HW, CC, BL and AC, genetic correlations ranged from 0.55 to 0.94.