FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / As informaÃÃes utilizadas neste estudo foram referentes aos dados de pesos de 228 novilhas leiteiras de diferentes grupos genÃticos das raÃas Holandesa e Gir (1/2, 3/4, 5/8, 7/8 e 15/16 HolandÃs x Gir), com o objetivo de ajustar modelos para descrever as curvas de crescimento de cada um dos grupos genÃticos. Para descriÃÃo das curvas de crescimento em funÃÃo do peso e idade desses animais foram ajustados os modelos de Brody, Von Bertalanffy, Richards, LogÃstico e Gompertz. O mÃtodo utilizado para o ajuste foi o interativo de Gauss Newton, por meio da tÃcnica dos modelos nÃo lineares usando-se o procedimento NLIN (SAS, 2001). AdequaÃÃo dos modelos foi observada atravÃs dos desvios encontrados atravÃs da diferenÃa entre os valores dos pesos estimados pelos modelos e os pesos observados nas pesagens dos animais nas idades 1, 210, 240, 270, 300, 330, 360, 390, 420 e 450 dias. Foi ainda avaliado, qual grupo genÃtico mostrou-se ser mais passÃvel a estimaÃÃo de pesos por modelos nÃolineares. O modelo LogÃstico foi o que melhor se adequou a maioria dos grupos genÃticos HolandÃs x Gir, pois apesar de superestimar os valores dos pesos, foi o mais indicado para representar pesos de animais 5/8, 7/8 e 15/16 HolandÃs x Gir. O grupo genÃtico 1/2 HolandÃs x Gir se apresentou como o mais passÃvel de estimaÃÃo atravÃs dos modelos estudados, em virtude de ser bem representado por todos os modelos, principalmente pelo modelo de Von Bertalanfy / The sub-basins of the Cipà and Carrapateira belong to the districts of Barra Nova and Santo
AntÃnio, which are part of Tauà Town in Cearà State, Brazil. These sub-basins are situated in one of
the most degraded areas in Tauà Town, according to studies of the WAVES Project. Tauà Town has
1,906.3 km of degraded areas susceptible to desertification, what represents 44.3% of the municipal
area, being characterized, according to the indexes established by the United Nations Organization,
as a semi-arid area with a high critical index (0.4), what expresses the fragility of the dry lands. It has
the following natural geo-ecological limitations: predominance of rocks having a crystalline base,
average temperature around 25ÂC to 28ÂC, enabling a high evaporation rate and, as a result, negative
values in the annual water balance; shallow and stony soils; a degraded ciliary plant cover due to the
secular agro-extractivist activity, favoring sediment deposition in the riverâs bed and the river marginsâ
widening, what endangers the water and pedological potential of the region. The combined action of
the weather, of the geological conditions and the shallow soils of the region produces a fragile
ecosystem, which reflects on the vegetation in the area, in which the caducifolia formation, with an
arboreous and shrubby physiognomy, is unable to offer protection to the soils against the erosive
effects, as observed in the study area. Because the ciliary vegetation is seriously threatened by the
inadequate soil use, there is a need of detailed studies, such as: floristic composition and structure of
the community, to check the plant community's condition in its current state in order to enable its
rational use and sustainability in view of the unbalance in which it is. It is worth pointing out that the
protection of the ciliary forest is of utmost importance for the good condition of water resources. It is
important to preserve and restore the forests along the rivers and around lakes and reservoirs
because that vegetation brings lots of benefits to the ecosystem, having the function of protecting the
biotic and abiotic natural resources. This way, the research had the following main objectives: a) to
analyze the ecosystem of the ciliary forest of the brooks Cipà and Carrapateiras, in order to obtain
indicators of environmental degradation by checking the effects of agricultural activities and of the
vegetable extractivism on the conditions of the potential communities of that vegetation conditions,
combining those activities with other environmental factors, and; b) to make a phytosociological survey
of the ciliary forest, supplying information to a database that leads to the sustainable land use to avoid
or stop the degradation process, enabling a better life quality for the local population. The
phytosociological studies showed significant differences between the two sample areas, in which the
forest of the brook Cipà was more conserved with specimen of the ciliary forest, while the forest of the
brook Carrapateiras totally is completely uncharacterized because of the high anthropic action.
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:3340 |
| Date | 25 July 2008 |
| Creators | Bartolomeu Neto Oliveira Martins |
| Contributors | SÃnia Maria Pinheiro de Oliveira, Francisco de Assis Melo Lima, Gabrimar AraÃjo Martins |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em Zootecnia, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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