Comportamento alimentar de caprinos em pastejo e características morfo-qualitativas de cíbalas em área de caatinga

Abstract

The management of the caatinga can be an alternative to improve the quantity and quality of the forage and, consequently, the animal performance. Thus, there is a need for the development of lines of studies that report the qualitative and quantitative changes of native Caatinga forages, as well as the cycling of nutrients in this system. The general objective of the thesis was to evaluate the contribution of the pellets to the nutrients of the soil and the feeding behavior of goats in caatinga areas under grazing. The experiment was conducted in the Brazilian semi-arid with hyperoxerophilic Caatinga vegetation. Three areas with different goat stockings were used: Area I with ten (0.15 AU.ha-1), Area II with five (0.09 AU.ha-1). and Area III without animals. Goats Sem padrão racial definido (SPRD) with mean body weight of 23 ± 2.3 kg were used. A floristic and phytosociological survey was carried out using the method of contiguous plots in an area of one hectare within the three areas, which were divided into 100 plots of 10 m x 10 m. Behavioral assessments occurred in two areas with animals in three periods: Rainy, Transition and Dry. In each area, three animals were used for observation, in which one of the animals had a GPS and a camera. Each animal was monitored by direct observation, with the aid of an etogram chart. The pellets samples were performed in the two areas with goats previously mentioned in 120 plots of 10 m x 10 m. It was performed a triage of the scales by hue, obtaining five different shades. Afterwards a pool by hue was realized to constitute an analytical sample for the analyzes of the chemical, physical and microbiological characteristics. In the floristic and phytosociological surveys, the presence of nine families and 17 species was observed; in Area I, the greatest number of species (14) and family (8) were found, in Area II and in Area III the presence was of 12 species. In Area I and Area II the similarity was 86% and between Area I and Area III, 82%; between Area II and Area III 79%. Area III had the largest number of individuals (3,732), Area I was lower in 20.40% and Area II was 31.30%. The C. sonderianus showed a value of importance (VI) and a higher coverage value (VC) in Area III (84.57 and 67.15%), P. pyramidalis presented higher LV and VC in Area II (91.97 and 7.139%) and P. gounellei was higher in area I (73.44 and 55.65%). Area I showed a strong grouping tendency (57.5%), in Area II the species varied from grouped (41.67%) to clustering (33.33%) and in area III the distribution was uniform (50%) with tendencies to grouping xix (41.67%). The values obtained for Area I were 1.591 and 0.603, for Area II of 1.669 and 0.6716 and for Area III of 1.642 and 0.6401, for the H 'and J' indices respectively. The time spent by animals grazing, walking and leisure depended (P<0.005) on the interaction, while ruminating and browsing presented a difference (P<0.005) between the periods. In relation to grazing times, there was a significant interaction (P<0.005) between the area and the period for herbaceous/subarctic and litter variables, in the others, there was a significant difference (P<0.005) between the periods in the grass, bromeliaceae and cactus variables and between the areas in the shrub/tree variable. There was interaction in the variables P, K, C, OM, C/P and C/N, being deployed. There was a difference between the shades for the N and C/N variables. In the physical characteristics there was an interaction effect for the variables density and length, which were unfolded and, in the microbiological characteristics, a significant difference was observed between the areas in shades 1 and 3. The phytosociological parameters show that the greatest contribution of forage biomass comes from the species P. pyramidalis, P. gounellei and C. sonderianus. Through dendrometric measurements it is possible to estimate the biomass of Caatinga trees, mainly C. sonderianus and P. pyramidalis, using multiple linear equations. There is high alimentary plasticity of the goats in the selection of forage species, as well as of the consumed structures, according to the availability of the mass and floristic composition, sometimes as browsers, or as grazers. The spatial distribution of the goat's pellets distribution patterns as a function of spatial location. The different nuances related to the length of time affects the physical standards of the stool, gradually reducing the crushing force. The chemical composition of faeces presents reduced variability, which influences of the fungi and bacteria colonization.