Connectivity of fragmented amphibian populations in a neotropical landscape

A high proportion of amphibian species are threatened with extinction globally, and habitat loss and degradation are the most frequently implicated causes. Rapid deforestation for the establishment of agricultural production is a primary driver of habitat loss in tropical zones where amphibian diversity is highest. Land-cover change affects native assemblages, in part, through the reduction of habitat area and the reduction of movement among remnant populations. Decreased gene flow contributes to loss of genetic diversity, which limits the ability of local populations to respond to further environmental changes. The focus of this dissertation is on the degree to which common land uses in Sarapiquí, Costa Rica impede the movement of two common amphibian species. First, I used field experiments, including displacement trials, and a behavioral landscape ecology framework to investigate the resistance of pastures to movement of Oophaga pumilio. Results from experiments demonstrate that pastures do impede movement of O. pumilio relative to forest. Microclimatic effects on movement performance as well as limited perceptual ranges likely contribute to reduced return rates through pastures. Next, I linked local processes to landscape scale estimates of resistance. I conducted experiments to measure habitat-specific costs to movement for O. pumilio and Craugastor bransfodrii, and then used experimental results to parameterize connectivity models. Model validation indicated highest support for resistance estimates generated from responses to land-use specific microclimates for both species and to predator encounters for O. pumilio. Finally, I used abundance and experiment-derived resistance estimates to analyze the effects of prevalent land uses on population genetic structure of the two focal species. While O. pumilio did not exhibit a strong response to landscape heterogeneity and was primarily structured by distances among sites, C. bransfordii genetic variation was explained by resistance estimates from abundance and experiment data. Collectivity, this work demonstrates that common land uses can offer different levels of resistance to amphibian movements in Sarapiquí and illustrates the value of investigating local scales processes to inform interpretation of landscape-scale patterns.^

Resposta de ovinos naturalmente infectados por nematoides gastrintestinais em pastos de capim-massai

The aim of this study was to evaluate the crossbred sheep Santa Ines response to natural infections by gastrointestinal nematodes in Panicum maximum cv. pastures Massai at different times of grazing. For this it was used 36 crossbred sheep Santa Inês, divided into four groups and randomly distributed in massai-grass pickets naturally infected by gastrointestinal nematodes. In the period from October 2013 to May 2014, the animals were weekly monitored for hematology tests (packed cell volume) and parasitological (egg counts per gram of feces and fecal culture) in order to monitor the level of infection of sheep and they were assessed for weight, body condition score and staining ocular mucosa by FAMACHA© method. Furthermore infective larvae was recovery from pasture in times of pre-and post-grazing pasture. At 35 kg body weight, the animals were slaughtered and necropsied to collect the contents of the abomasum and small and large intestines to recover the adult parasites, carrying out the count and identification. The animals on pasture with a height of 40 cm pre-grazing obtained low nematode eggs in feces (1608 eggs / g) and 33 cm those in pre-grazing the highest average (2,539 eggs / g). The animals in different groups showed mean values of packed cell volume less than 23% (P> 0.05). Regarding to FAMACHA, the animals belonging to the groups 40 and 50 cm pre-grazing remained over 50% of individuals between FAMACHA 1 and 2 , and those to 33 and 45 cm pre-grazing showed mostly between FAMACHA 3, 4 and 5 (69.06% and 58.93%, respectively). In the culture of larvae in feces and recovery of pasture larvae before and after grazing the following genera were found, in order of prevalence: Haemonchus, Trichostrongylus, Oesophagostomum and Strongyloides. The pasture with 33 cm of pre-grazing provided the highest number of larvae recovered both in the pre and post-grazing (1,081 and 715 L3 / 100 g of green matter, respectively). Among the different groups, the sheep had an average weight of between 23 and 26 kg and variation between the body 1 and 3 scores with scores greater frequency of 1.5 to 2.It can be observed that the animals kept at different times of grazing got different answers on the parasite load. Animals kept in 40 cm pre-grazing expressed a satisfactory answer than the other groups (33, 45 and 50 cm), best supporting the action of endoparasites. Moreover, this same height, was recovered fewer infective larvae on pasture in pre and post-grazing.

Perfil sorológico contra Rickettsia spp e Leptospira spp e infestação de carrapatos em suínos mantidos sob diferentes sistemas de criação

The various types of pig farming, intensive and extensive, expose them to pig parasites but also to those from the environment of the breeding site. In this work was evaluated the exposure of bigs bred in technified farms, SISCAL (intensive breeding system in pens) and not technified (backyard) to leptospira, ticks and rickettsiae. Blood sera were analyzed to determine titers of antibodies anti-Leptospira by SAM technique and antibodies anti-rickettsial by IFA, pigs were inspected for ticks and in their breeding environment and surrounding areas (pastures and riparian vegetation), ticks were collected by the flannel dragging technique. In the farms of pigs 10.4% had anti-Leptospira antibodies, followed by SISCAL (8%) and backyard animals (2.5%). The serovars found were Bratislava, Pomona, serovar, Canicola and Icterohaemorrhagiae. Higher percentage of properties with pigs raised outdoors (SISCAL) had tick infested animals (20%) than those raised in backyard (6.7%), while commercial farms had no infested pigs nor infested breeding place. In both SISCAL and backyard pig breeding properties ticks were observed at the breeding site environment. Tick infestations were detected in areas surrounding pig breeding site in all three husbandry suystems. Ticks found were all Amblyomma scultpum nymphs or adults with the exception of one of Amblyomma parvum adult. In relation to anti-rickettsia serology to five Rickettsia species, 55.2% of pigs from commercial farms reacted to al least one species, backyard pigs reacted to 89.7% and all pigs of SISCAL showed anti-rickettsia titers. Consecutive tick sampling (June 2014 to February 2016) in SISCAL FAZU in Uberaba, showed the establishment A. sculptum ticks maintained by domestic pigs. These observations demonstrate the ability the pigs to maintain populations of A. sculptum at a favorable environment and may indicate a new trend in environmental infestations by this species of tick. Exposure to Leptospira and Rickettsia demonstrated the potential pigs exposure and transmission of important diseases in public health.

Estrutura e dinâmica de perfilhamento do capim-marandu com alturas variáveis no inverno

The livestock system in Brazil mainly uses the pastures as source of food to cattle, and the marandu palisade grass is one of the main forage crop plants. In order to supply the demand of these animals in amount of forage, it is necessary to adopt management strategies aimed at increased forage production with adequate characteristics to animal intake. In this context, is requiered to identify management strategies of defoliation that improve tillering of marandu palisade grass during the seasons. There is a chance that the maintenance of lower marandu palisade grass during the fall and winter compared to spring and summer, increase the incidence of light at the base of the plants and, indeed, encourage tillering and modify the structure of the pasture compared to maintain marandu palisade grass with constant height along these stations.

American Manna: Religious Responses to the American Industrial Food System

“American Manna: Religious Responses to the American Industrial Food System” is an investigation of the religious complexity present in religious food reform movements. I conducted ethnographic fieldwork at four field sites. These field sites are a Jewish organic vegetable farm where the farmers begin their days with meditation, a Christian raw vegan diet center run by Messianic Jews, a Christian family that raises their cattle on pastures and sends them to a halal processing plant for slaughter, and a Jewish farm where Christian and Buddhist farm staff helped to implement shmita, the biblical agricultural sabbatical year.

The religious people of America do not exist in neatly bound silos, so in my research I move with the religious people to the spaces that are less clearly defined as “Christian” or “Jewish.” I study religious food reformers within the framework of what I have termed “free-range religion” because they organize in groups outside the traditional religious organizational structures. My argument regarding free-range religion has three parts. I show that (1) perceived injustices within the American industrial food system have motivated some religious people to take action; (2) that when they do, they direct their efforts against the American food industry, and tend to do so outside traditional religious institutions; and finally, (3) in creating alternatives to the American food industry, religious people engage in inter-religious and extra-religious activism.

Chapter 1 serves as the introduction, literature review, and methodology overview. Chapter 2 focuses on the food-centered Judaism at the Adamah Environmental Fellowship at the Isabella Freedman Jewish Retreat Center in Falls Village, CT. In Chapter 3, I discuss the Hallelujah Diet as prescriptive literature and as it is put into practice at the Hallelujah Diet Retreat Center in Lake Lure, NC. Chapter 4 follows cows as they move from the grassy hills of Baldwin Family Farms in Yanceyville, NC to the meat counter at Whole Foods Markets. In Chapter 5, I consider the shmita year, the biblical agricultural sabbatical practice that was reimagined and implemented at Pearlstone Center in Baltimore, MD during 2014-2015. Chapter 6 will conclude this dissertation with a discussion of where religious food reform has been, where it is now, and a glimpse of what the future holds.

Connectivity of fragmented amphibian populations in a Neotropical landscape

A high proportion of amphibian species are threatened with extinction globally, and habitat loss and degradation are the most frequently implicated causes. Rapid deforestation for the establishment of agricultural production is a primary driver of habitat loss in tropical zones where amphibian diversity is highest. Land-cover change affects native assemblages, in part, through the reduction of habitat area and the reduction of movement among remnant populations. Decreased gene flow contributes to loss of genetic diversity, which limits the ability of local populations to respond to further environmental changes. The focus of this dissertation is on the degree to which common land uses in Sarapiquí, Costa Rica impede the movement of two common amphibian species. First, I used field experiments, including displacement trials, and a behavioral landscape ecology framework to investigate the resistance of pastures to movement of Oophaga pumilio. Results from experiments demonstrate that pastures do impede movement of O. pumilio relative to forest. Microclimatic effects on movement performance as well as limited perceptual ranges likely contribute to reduced return rates through pastures. Next, I linked local processes to landscape scale estimates of resistance. I conducted experiments to measure habitat-specific costs to movement for O. pumilio and Craugastor bransfodrii, and then used experimental results to parameterize connectivity models. Model validation indicated highest support for resistance estimates generated from responses to land-use specific microclimates for both species and to predator encounters for O. pumilio. Finally, I used abundance and experiment-derived resistance estimates to analyze the effects of prevalent land uses on population genetic structure of the two focal species. While O. pumilio did not exhibit a strong response to landscape heterogeneity and was primarily structured by distances among sites, C. bransfordii genetic variation was explained by resistance estimates from abundance and experiment data. Collectivity, this work demonstrates that common land uses can offer different levels of resistance to amphibian movements in Sarapiquí and illustrates the value of investigating local scales processes to inform interpretation of landscape-scale patterns.

Effects of time-controlled and continuous grazing on total herbage mass and ground cover

Grazing practices in rangelands are increasingly recognized as a management tool for environmental protection in addition to livestock production. Long term continuous grazing has been largely documented to reduce pasture productivity and decline the protective layer of soil surface affecting environmental protection. Time-controlled rotational grazing (TC grazing) as an alternative to continuous grazing is considered to reduce such negative effects and provides pasture with a higher amount of vegetation securing food for animals and conserving environment. To research on how the grazing system affects herbage and above ground organic materials compared with continuous grazing, the study was conducted in a sub-tropical region of Australia from 2001 to 2006. The overall results showed that herbage mass under TC grazing increased to 140% in 2006 compared with the first records taken in 2001. The outcomes were even higher (150%) when the soil is deeper and the slope is gentle. In line with the results of herbage mass, ground cover under TC grazing achieved significant higher percentages than continuous grazing in all the years of the study. Ground cover under TC grazing increased from 54% in 2003 to 73%, 82%, and 89% in 2004, 2005, and 2006, respectively, despite the fact that after the high yielding year of 2004 herbage mass declined to around 2.5 ton ha^(−1) in 2005 and 2006. Under continuous grazing however there was no significant increase over time comparable to TC grazing neither in herbage mass nor in ground cover. The successful outcome is largely attributed to the flexible nature of the management in which grazing frequency, durations and the rest periods were efficiently controlled. Such flexibility of animal presence on pastures could result in higher water retention and soil moisture condition promoting above ground organic material.

Opportunities and constraints of transhumant small ruminant production in the Chinese Altay Mountains

This PhD thesis focuses on current livelihoods of agro-pastoral livestock keepers, their animal nutrition, herd and rangeland management strategies. It thereby aims to contribute to sustainable rangeland management, livestock production and household income in Qinghe county of the Chinese Altay Mountain region, located in Xinjiang Uyghur Autonomous Region, PR China. In its first part the study characterizes the socio-economic situation and agricultural practices of agro-pastoralists through structured household interviews. The second part provides insights into the grazing behaviour and feed intake of small ruminants on seasonal pastures in this region, and into the quantitative and qualitative biomass offer on natural rangelands. The third part analyses the reproductive performance and annual growth of the local sheep and goat herds, and, by modelling improved feeding and culling strategies, tests herd management options that potentially improve the monetary output per female herd animal without increasing the pressure onto natural rangelands. Taken together, the results of the study suggest that, despite an increase and intensification of cropping and vegetable gardening in the region of Qinghe, livestock rearing is still the major livelihood strategy both in terms of prevalence and relative importance. However, livestock keeping is challenged by low biomass production on rangelands, due to the combined impact of high climate variability and highly localized grazing pressure on the seasonal pastures. Though government regulations try to tackle the latter aspect, their implementation is sometimes difficult. Alternatives to strict regulation of grazing periods and animal numbers on seasonal pastures are, in the case of goats, more rigorous culling strategies and, in the case of sheep and goats, strategic supplementation of the animals in the winter and spring season. However, for the latter strategy to become economically viable, an improvement of live animal and meat marketing options and an investment in local meat processing facilities that add value to the carcasses is needed. As the regional cities grow rapidly, the potential market to absorb diverse and good quality meat products is there, along with the road network connecting Qinghe county to the regional capital. Such governmental measures will not only create new job opportunities in the region but also benefit the cash income of pastoralists in this westernmost region of China.

Adubação de sistemas: antecipação de adubação nitrogenada para a cultura do milho em integração lavoura-pecuária

Traditionally in no-tillage systems, fertilization is done to the catch crop. In general nutrient cycling in crop systems has not been treated as an important tool in the process of nutrient supplying for plants. The type and the condition in which vegetable residuesis decomposed can affect the efficiency of nutrient cycling.This study assessed the effect of anticipated nitrogen fertilization in crop-livestock systems on cultivated cornproduction, rate ofnutrient release from plant residue, and theN-minerallevels of soil. The study was carried out in the city Abelardo Luz (SC) in a Clayey Oxisol. The experimental design was a randomized block design with three replications. The treatments were arranged in a 2 x 2 factorial arrangement. The first factor was N Fertilization Time: in the N-Pasture level, nitrogen (200 kg ha-1 N) and N-Grains level, no nitrogen was applied. The second factor was the Grazing Height, characterized by two sward heights of oat at 15 cm (Low Height Pasture) and at 30 cm (High Height Pasture). Corn hybrid ‘Máximus’ was sowed in 10thOctober, 31 days after the removal of animals. In the twelve resulting plots from the combination of treatments on pasture phase (N Fertilization Time x Grazing Height) rates of N-fertilizer (0, 100, 200 e 300 Kg ha-1 of N) as urea were allocated in the split plot.We conclude that anticipated N fertilization of winter cover crop pasture to provide high-quality forage and carry-over N to the subsequent corn crop and may eventually replace side drees nitrogen fertilization on corn and can improve overall N fertilizer efficiency use in integrated crop-livestock systems.The rate of K release from plant residues is very fast, releasing large quantities in the first days after plant desiccation.Despite of considerably high nitrogen dose used in both the pasture and at the grain crop it was not observed nitrate leaching risks during the study period.

Macrofauna epígea de besouros coprófilos em sistema de integração lavoura-pecuária

The soil macrofauna (organisms ≥ 2.0 mm) main function is to act indirectly on the decomposition of organic matter and control the population of microorganisms. This study aims to evaluate the density and richness of coprphilic dung beetles at different levels of nitrogen fertilization and grazing pressure on Crop-Livestock Integration System (ILP) and his opposition to morphotypes present in the native forests of the region. Was used a rural area in Abelardo Luz city, western state of Santa Catarina, on the border of southwest of Paraná, 26° 31' 18.8832" south latitude and 52° 15' 3.4986' west longitude and elevation 862 m for the installation of the experiment, which is already carried out the activity of agriculture and livestock. The study is part of the Integrated Project of Long Duration GISPA UTFPR Group, which evaluates the grazing pressure and time of fertilization deployed in April 2013. The experimental design was a randomized complete block design in a 2x2 factorial arrangement with three replications. The factors were "Nitrogen Application" (NP = N in the pasture and NG = N applied in corn) and "Height Grazing" (high and low). The native forest, which provided the parameters for assessing the degree of conservation, lies 700 meters northeast of the experimental area. Modified pitfall traps were used at ground level, on the bait trap and covered together to prevent dehydration. They were carried out 36 collections in bushland, within one year from 26 April 2013, in which we obtained a total of 16,301 individuals and 28 morphotypes. In ILP area specimens were collected from June to September 2014, totaling 23 collections, 74,586 individuals and 30 morphotypes. To carry out the statistics and faunal analysis, GENES programs were used, ANAFAU, NTIA/EMBRAPA and SigmaPlot version 12.5. Most of the correlations observed (90%) between the variables of insects and environmental conditions was significant. The largest number of insects was directly related to the temperature rise. There was a positive correlation between the application of nitrogen and the occurrence of coprophilous. There was a positive correlation between the number of insects and low grazing height. It was also found that some of the insects migrate from the culture to the area of native forest after reaching their peak population. The great similarity of results observed in the native forest and the ILP System indicates the ecological benefits of adopting this technology.

Supplementation of cattle fed tropical grasses with microalgae increases microbial protein production and average daily gain

A series of 3 experiments were conducted to evaluate the use of microalgae as supplements for ruminants consuming low-CP tropical grasses. In Exp. 1, the chemical composition and in vitro protein degradability of 9 algae species and 4 protein supplements were determined. In Exp. 2, rumen function and microbial protein (MCP) production were determined in Bos indicus steers fed speargrass hay alone or supplemented with Spirulina platensis, Chlorella pyrenoidosa, Dunaliella salina, or cottonseed meal (CSM). In Exp. 3, DMI and ADG were determined in B. indicus steers fed speargrass hay alone or supplemented with increasing amounts of NPN (urea combined with ammonia sulfate), CSM, or S. platensis. In Exp. 1, the CP content of S. platensis and C. pyrenoidosa (675 and 580 g/kg DM) was highest among the algae species and higher than the other protein supplements evaluated, and Schizochytrium sp. had the highest crude lipid (CL) content (198 g/kg DM). In Exp. 2, S. platensis supplementation increased speargrass hay intake, the efficiency of MCP production, the fractional outflow rate of digesta from the rumen, the concentration of NH3N, and the molar proportion of branched-chain fatty acids in the rumen fluid of steers above all other treatments. Dunaliella salina acceptance by steers was low and this resulted in no significant difference to unsupplemented steers for all parameters measured for this algae supplement. In Exp. 3, ADG linearly increased with increasing supplementary N intake from both S. platensis and NPN, with no difference between the 2 supplements. In contrast, ADG quadratically increased with increasing supplementary N intake from CSM. It was concluded that S. platensis and C. pyrenoidosa may potentially be used as protein sources for cattle grazing low-CP pastures.

Características químicas do solo e desempenho de culturas após quatro anos de aplicações de cama de aviário em diferentes épocas e níveis

Due to the high supply and its attractive cost, the poultry litter has been used in the southwestern region of Parana to the improvement of soil fertility seeking greater production of grains and pastures. However, the use without technical knowledge can minimize the benefits of poultry litter or even cause undesirable effects on soil, environmental pollution and also productivity losses in the used crops. The objective of this study was to evaluate the influence of different times of poultry litter application, predating the winter crop, associated with increasing levels, about soil chemical properties, release of nutrients and crop performances in four consecutive years (2011-2014). In the first three years the experimental design was randomized blocks with a split plot system and four replications. In the main plots were tested four poultry litter application times preceding the wheat production: 0, 15, 30 and 45 days before sowing (DAS); in the subplots were applied four poultry litter levels (wet basis): 0, 4, 8 and 12 Mg ha-1. Last year one more subdivision of plots was done, evaluating the use or not of nitrogen in coverage in wheat, at a dose of 100 kg N ha-1. The wheat cultivar used in the four years was the BRS 220. In three years it was evaluated the residual effect on soybean production (cultivar - BMX Turbo RR) and in one year on the beans. The chemical soil attributes were evaluated at four depths 0-2,5cm, 2,5-5cm, 5-10cm and 10-20cm, and also the rate of decomposition and nutrient release of poultry litter and the crop productivity. The different times of application concerning the poultry litter had little influence on the studied variables, demonstrating that the producer does not need to have a specific date (before planting) to the application of poultry litter. Potassium was fully released 60 days after the allocation of litter bags into the field; for nitrogen and phosphorus the release was slower. The use of increasing levels of poultry litter increased the levels of various soil elements, highlighting the potassium which reached 20 cm deep in the second year of evaluation. The increase in pH and in the base saturation occurred only in the upper layers, while the phosphorus reached 10 cm deep in the third year of the study. It was observed increased pH and base saturation. The use of increasing doses of poultry litter contributed to the wheat plant nutrition, significantly increasing the weight of a thousand grains, and the grain yield of wheat in all the evaluated years; the nitrogen fertilization in coverage also had significant effect for the fourth evaluated year. Also there was a significant response from the residual effect of poultry litter for crops planted in summer for both soybeans and beans.

Recent development and commercial adoption of legumes for heavy clay soils in Queensland

In previous chapters of this volume, various authors describe the development of herbaceous legumes for pastures on clay soils in Queensland until about the 1980s. Emphasis is on the collection and evaluation of the genus Desmanthus, given its relatively recent addition to agriculture and considerable potential for providing useful pasture legumes for clay soils, particularly in the seasonally dry areas of northern Australia. Other genera are also discussed, including early assessments of herbaceous legumes that were later developed for clay soils (Clitoria, Macroptilium and Stylosanthes). This chapter provides a summary of the development of herbaceous legumes for clay soils in Queensland from these earlier assessments until present. Beef cattle farming is the principal agricultural enterprise in seasonally dry areas of northern Australia, including large areas of clay soils in Queensland. Sown and naturally occurring grasses provide the key feed resource, and the inclusion of sown legumes can significantly improve live-weight gain and reproductive performance per unit area. Queensland has been the centre of development for legumes for clay soils in tropical and subtropical areas of Australia, mostly through assessing and developing plants held in the Australian Tropical Forages Genetic Resource Collection (ATFGRC) (now a component of the Australia Pastures Genebank (APG)). The systematic appraisal of genetic material for clay soils was a focus of well-resourced government research up to the early to mid-1990s, but declined thereafter as sown pasture research teams were dismantled and funding to maintain the ATFGRC declined. Cultivar development is now conducted by small government, private enterprise and university research teams that collaborate where possible. In recent studies the use of experienced researcher knowledge and old plant evaluation sites has been particularly valuable for identifying potentially useful material. Cultivars for long- and short-term pastures on clay soils have been developed to the level of commercial seed production for Desmanthus (five cultivars from four species with two cultivars (one composite) in current use), Clitoria ternatea (one cultivar), Macroptilium bracteatum (two) and Stylosanthes seabrana (two). Other potential cultivars of these species are currently in various stages of development. Each species has different production niches depending on climate, clay soil type and grazing strategy. Adoption of these cultivars is occurring but has variously been impeded by limited promotion, mismatch of seed supply and demand, and difficulty establishing legumes in pastures of some key grass species. Recent renewed investment by the Australian Beef Industry has seen revived government research into pasture legumes in Queensland and rejuvenation of the APG.

Impacto del uso de los sistemas de alimentación a corral como estrategia para el engorde de bovinos para carne

El confinamiento estratégico de los bovinos Argentina es una herramienta muy útil para lograr la terminación de animales destinados al consumo interno y a la exportación. La utilidad de estos encierres consiste permitir un mejor aprovechamiento del forraje y reduciendo la edad a la faena. Para su aplicación es necesario considerar los factores que afectan su resultado económico tales como la característica de las dietas utilizadas, los niveles de consumo y la eficiencia de conversión. Esto interactúa a su vez con el tipo de animal a encerrar. Son dos los sistemas de confinamiento estratégico que van a ser considerados en esta presentación: los corrales de engorde o terminación y los de recría o engorde de los terneros posdete. La actividad del engorde a corral durante los últimos años, ha estado ligada a variaciones operadas en el precio del grano y del tipo de producto logrado. Hay variaciones atribuidas al cambio en las preferencias del consumidor y también al efecto de la concentración de las ventas de carne en determinadas bocas de expendio que exigen uniformidad en la entrega de animales y del tamaño de los cortes. Se comentan entonces algunos aspectos relevantes del engorde a corral americano y de los engordes a corral en Argentina, además de algunos factores que pueden afectar el resultado económico de la actividad. En cuanto al corral de recría, tiene como objetivo la mejora de la ganancia de peso durante esta etapa frente a condiciones de recría a pasto donde pueden existir limitantes en la cantidad y calidad del forraje producido. En esta presentación se hace el comentario y el análisis de los factores a tener en cuenta en los dos tipos de manejo de los animales a corral: los de terminación o engorde final y los de recría o engorde de terneros después del destete. En el primer caso, los efectos del sexo, la edad, la eficiencia de conversión, la raza, el estado nutricional previo, así como factores de la dieta en si mismo. En el segundo caso se analizan sobre todo los distintos tipos de terneros que pueden incorporar al sistema, así como el uso de diferentes dietas. El desarrollo de los encierres de terneros permitió diseñar nuevos sistemas de producción basados en un aumento de la carga, de la ganancia de peso, la modificación del peso final y los posibles cambios en el momento de terminación. En el caso de los corrales de terminación, han sido una herramienta muy útil para lograr la terminación de animales destinados al consumo interno como exportación.

Evolución del paisaje y aprovechamientos económicos en la falda de la sierra cordobesa (Siglos XIII-XV)

La falda de la sierra cordobesa forma un espacio unitario íntimamente conectado geográfica, emocional y económicamente con la ciudad. En este espacio se sitúan elementos históricos tan importantes como el heredamiento de la Albaida o, sobre todo, la dehesa de Córdoba la Vieja, que recibe este nombre por encontrarse en su interior las ruinas de la antigua ciudad omeya de Madinat al-Zahra. Tradicionalmente se ha presentado este espacio como una amplia dehesa dedicada a la ganadería extensiva. Sin embargo, un estudio más detallado de las fuentes documentales disponibles nos muestra un paisaje diversificado en el que, junto con los pastos para el ganado, abundan olivares, viñas y huertas que fueron fundamentales para el abastecimiento de los mercados de la ciudad de Córdoba durante la Baja Edad Media.