Classificação morfológica de Bovinos de Raça Maronesa
Data
2020-02-19
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Atualmente, a classificação morfológica em bovinos leiteiros está avançada e estabilizada, enquanto nos bovinos de carne tem expressividade nas raças exóticas (por exemplo Limousine), mas não nas raças autóctones em que esta metodologia começa a fazer parte dos trabalhos diários das associações de criadores. Este estudo é um trabalho preliminar sobre a Classificação Morfológica de Bovinos de Raça Maronesa que visa elucidar a importância e as vantagens de se realizar esta metodologia, para uma implementação eficaz, permitindo uma posterior seleção dos animais, de forma a obter um melhoramento gradual na raça. Na primeira parte do trabalho, foi efetuada uma breve descrição da raça Maronesa, definindo a sua origem e padrão, o que é necessário ter em conta na avaliação/classificação morfológica de cada animal e a sua importância. Na segunda parte do trabalho foi analisada a base de dados da classificação morfológica com um total de 3230 animais classificados (3080 fêmeas e 150 machos). Foram propostos coeficientes de ponderação por característica linear de forma a determinar o grande grupo, e uma nova ponderação das grandes regiões para obter a pontuação final de cada animal, tendo em atenção o género do animal. Verificou-se que nas fêmeas a idade influenciou de uma forma geral a classificação das características, a maior pontuação foi obtida na categoria C (mais de 3 anos de idade). Há uma grande variabilidade de resultados nas pontuações das características pelos técnicos sendo maior nos machos, devido ao número reduzido de classificações. As correlações entre as características lineares são mais significativas dentro dos grupos quer para os machos quer para as fêmeas. Em relação à pontuação final verificou-se que mais de 96% dos animais classificados (machos e fêmeas), deste modo, cumprem os mínimos para entrar no livro genealógico de adultos da raça. Na relação dos grupos com as características lineares avaliadas por regressão linear múltipla verificou-se que em todos os grupos e por sexo estão significativamente associadas (p<0,0001), e a qualidade de ajustamento às retas era superior a 0,95. Exceto para as qualidades raciais nos machos que tem o valor de 0,15.
Currently, morphological classification in dairy cattle is already advanced and stabilized, while in beef cattle already expressive in exotic breeds (eg Limousine), but not in local breeds where this methodology is beginning to be part of daily work of breeders associations. This study is a preliminary work on the morphological classification of Maronesa cattle breed which aims to elucidate the importance and advantages of performing this methodology, for effective implementation and selection of animals, in order to obtain a gradual improvement in the breed. In the first part of the work, a brief description of the Maronesa Breed was made, defining its origin and traits of breed, which has to be taken into account in the morphological evaluation of each animal and its importance. In the second part of the work, the morphological classification database was analyzed with a total of 3230 classified animals (3080 females and 150 males). Weighting coefficients by linear trait were proposed to determine the group, and a new weighting of the groups to obtain the final score of each animal, taking into account the sex of the animal. It was found that in females the age influenced in general the classification of the traits, the highest score was obtained in category C of the age. There is a great variability of results in the traits scores by the technicians being higher in males, due to the reduced number of classifications. Correlations between linear traits are more significant within groups for both males and females. Regarding the final score it was found that over 96% of the animals classified (male and female) thus meet the minimums to enter the adult herd book. Regarding the relationship of the groups with the linear traits evaluated by multiple linear regression, it was found that in all groups and by sex they were significantly associated (p <0.0001), and the determination coefficient was greater than 0.95. Except for breed qualities relative to males which has a value of 0.15.
Currently, morphological classification in dairy cattle is already advanced and stabilized, while in beef cattle already expressive in exotic breeds (eg Limousine), but not in local breeds where this methodology is beginning to be part of daily work of breeders associations. This study is a preliminary work on the morphological classification of Maronesa cattle breed which aims to elucidate the importance and advantages of performing this methodology, for effective implementation and selection of animals, in order to obtain a gradual improvement in the breed. In the first part of the work, a brief description of the Maronesa Breed was made, defining its origin and traits of breed, which has to be taken into account in the morphological evaluation of each animal and its importance. In the second part of the work, the morphological classification database was analyzed with a total of 3230 classified animals (3080 females and 150 males). Weighting coefficients by linear trait were proposed to determine the group, and a new weighting of the groups to obtain the final score of each animal, taking into account the sex of the animal. It was found that in females the age influenced in general the classification of the traits, the highest score was obtained in category C of the age. There is a great variability of results in the traits scores by the technicians being higher in males, due to the reduced number of classifications. Correlations between linear traits are more significant within groups for both males and females. Regarding the final score it was found that over 96% of the animals classified (male and female) thus meet the minimums to enter the adult herd book. Regarding the relationship of the groups with the linear traits evaluated by multiple linear regression, it was found that in all groups and by sex they were significantly associated (p <0.0001), and the determination coefficient was greater than 0.95. Except for breed qualities relative to males which has a value of 0.15.
Descrição
Dissertação de Mestrado em Engenharia Zootécnica
Palavras-chave
bovinos , classificação morfológica