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Associação de polimorfismo do gene PIT1 com características de produção de carne em bovinos da raça Canchim
(Universidade Federal de São Carlos, 2004-06-29) Carrijo, Sônia Mara; Regitano, Luciana Correia de Almeida; https://lattes.cnpq.br/9595338480545794
The PIT1 gene codes for the pituitary transcription factor Pit-1, which is critical for the activation of the expression of prolactin and growth hormone genes, in addition to participating in the activation of PIT1 itself. The objective of the present study was to investigate the effect of HinfI polymorphism of this gene on meat production traits. The sample consisted of 509 Canchim animals born between 1998 and 2000. The sample included a traditional line (GG1) consisting of 5/8 Charolais genome breed and 3/8 of the Zebu breeds, Nelore, Guzerá and Indubrasil, and a new line (GG2) with 21/32 Charolais genome and 11/32 of the Nelore breed. The genotypes for the PIT1 gene were identified by PCR-RFLP. Genotype effect on phenotypic values for birth weight (BW), standardized weaning weight (W240) and at 12 month of age weight (W365), and on average daily weight gain to the born at weaning (GMND) and to the weaning at 12 month of age (GMD12), were analyzed by the least squares method. The results revealed significant effects of the interaction between genetic animal group and PIT1 genotype on W240, GMND and GMD12 (P < 0.05). The differences in mean least squares between genotype ( / ) and genotypes (+/+) and (+/ ) for W240 and GMND were significant in GG2 (P < 0,01 and p < 0,05, respectively), revealing superiority of the ( / ) genotype on that characters. The means for genotypes (+/+) and (+/ ), respectively at the W240 and GMND, did not differ from one another, suggesting a dominance effect of the HinfI (+) allele. The means effects of the HinfI ( ) allele indicated a positive effect of this allele on W240 and GMND, and the deviation estimates attributed to dominance showed a favorable effect of the HinfI ( ) allele on W240 and GMND of GG2 animals, when present in homozygosis in the genotypes of the individuals. The means of the genotypes in GG1 did not differ from one another. The difference in PIT1 behavior observed in the two genetic groups, however, may suggest the action of a quantitative trait locus linked to PIT1 segregating only in GG2 of the population studied, and not a direct effect of PIT1.
Determinantes da tomada de decisão sobre as atividades produtivas rurais: proposta de um modelo para a produção familiar.
(Universidade Federal de São Carlos, 2004-06-29) Vilckas, Mariângela; Nantes, José Flávio Diniz; https://lattes.cnpq.br/1900976112613026
The family small farms represent a very important segment in the national economy since it plays an important role in food production, incoming generation and distribution and land occupation. However, this segment is characterized by an inadequate management, which commits its competitiveness. The main aim of this reasearch is to propose a practical and accessible production planning model for vegetables raising family farms, which can help them to consider internal and external factors when deciding what to produce. The methodology had four main stages: (i) interviews with families that raise vegetables from São Carlos, São Paulo, in order to identify the production systems and the planning of the production activities; (ii) working out a planning model; (iii) interviews with rural management and vegetable production specialists, to confirm factors used in the model, the weights given to each factor and the notes for the possibilities of the producer reality; (iv) correction and final mode s working out. When interviewing the producers, it was observed that they don t have many years of formal education, most of the families are led by 30 39 years old men, there is a wide participation of women in the labor and few producers have employees. Within 33 interviewed producers, 11 have decided to get specialized, producing from 1 to 5 vegetables options, specially the green ones. The producers do not have a structured methodology to make decisions, and they do not consider all the factors that may influence the decision of what they should produce. Concerning to the planning model, the considered factors in the decision were grouped in internal (natural, human, financial and technological resources) and external (demand, offer and support services), but the use of weights were adopted only with the internal factors. The interviewed specialists emphasized the importance of making the correct decision about choosing the product variety to be raised and also about getting organized through associations and cooperatives. This study is an initial reasearch , which may be used as a subsidy for other rural planning studies. Although the decision model proposed has been developed to be used by producers, it may be also useful for rural projects, cooperatives, associations and financial agents, since it proposes a methodology to analyze the products options.