Distal limb osteoarthritis in the horse

The aim of this thesis was to study two objective methods of osteoarthritis (OA) diagnosis in horses and use them on the assessment of new intra-articular treatments. The studied methods were a new inertial-sensor based system of lameness detection and cartilage biomarkers in serum. It was found that distal limb flexion is significantly correlated to the presence of metacarpo-phalangeal OA in hind limbs and that inertial-sensors are sensitive in detecting asymmetry in these cases. A positive and significant correlation was observed between Coll2-1 concentration in serum and the presence of joint disease in males and young horses. Fib3-2 measurement has good potential to be used since it is not influenced by sex or age. Using an experimental model of OA, adipose stem cells pre-activated with interferon-gamma decreased joint inflammation and radiographic lesions. In clinical cases, a single injection of high-concentrated and high-molecular weight hyaluronic-acid decreased joint inflammation and biomarkers’ concentration; OSTEOARTRITE DO MEMBRO DISTAL NO CAVALO Resumo: A finalidade desta tese foi estudar dois métodos de diagnóstico objetivo de osteoartrite (OA) em equinos e aplicá-los na avaliação de novas terapias intra-articulares. Utilizou-se um sistema de sensores de movimento e foi avaliada a concentração de biomarcadores de cartilagem no soro. Concluiu-se que a flexão distal positiva está correlacionada com OA na articulação metacarpofalângica nos membros posteriores e que os sensores são sensíveis na detecção de assimetria nestes casos. Existe uma correlação positiva e significativa entre as concentrações de Coll2-1 e a presença de doença articular, sobretudo em machos e jovens. A dosagem de Fib3-2 tem utilidade por não ser influenciada pelo sexo nem idade. Num modelo experimental da doença, a terapia à base de células estaminais reduziu a inflamação articular e as lesões radiográficas. Em casos clínicos, o tratamento com ácido-hialurónico de alta concentração e peso molecular provoca uma diminuição da inflamação articular e dos biomarcadores no soro.

Evaluation of DUALEM, OptRx and Grassmaster II sensors for monitoring the spatial variability and the temporal stability of a Mediterranean pasture

Site-specific management (SSM) is a form of precision agriculture whereby decisions on resource application and agronomic practices are improved to better match soil and crop requirements as they vary in the field. SSM enables the identification of regions (homogeneous management zones) within the area delimited by field boundaries. These subfield regions constitute areas that have similar permanent characteristics. Traditional soil and pasture sampling and the necessary laboratory analysis are time-consuming, labour-intensive and cost prohibitive, not viable from a SSM perspective because it needs a large number of soil and pasture samples in order to achieve a good representation of soil properties, nutrient levels and pasture quality and productivity. The main objective of this work was to evaluate technologies which have potential for monitoring aspects related to spatial and temporal variability of soil nutrients and pasture green and dry matter yield (respectively, GM and DM, in kg/ha) and support to decision making for the farmer. Three types of sensors were evaluated in a 7ha pasture experimental field: an electromagnetic induction sensor (“DUALEM 1S”, which measures the soil apparent electrical conductivity, ECa), an active optical sensor ("OptRx®", which measures the NDVI, “Normalized Difference Vegetation Index”) and a capacitance probe ("GrassMaster II" which estimates plant mass). The results indicate the possibility of using a soil electrical conductivity probe as, probably, the best tool for monitoring not only some of the characteristics of the soil, but also those of the pasture, which could represent an important help in simplifying the process of sampling and support SSM decision making, in precision agriculture projects. On the other hand, the significant and very strong correlations obtained between capacitance and NDVI and between any of these parameters and the pasture productivity shows the potential of these tools for monitoring the evolution of spatial and temporal patterns of the vegetative growth of biodiverse pasture, for identifying different plant species and variability in pasture yield in Alentejo dry-land farming systems. These results are relevant for the selection of an adequate sensing system for a particular application and open new perspectives for other works that would allow the testing, calibration and validation of the sensors in a wider range of pasture production conditions, namely the extraordinary diversity of botanical species that are characteristic of the Mediterranean region at the different periods of the year.