Nutrition has a very significant impact on animal performance. Given the limited agricultural area of the Azores, the optimization of forage quality, quantity, and availability is key for the local livestock industry’s ability to respond to the challenges of an increasingly globalized market. This work’s goal was to evaluate the use of near-infrared spectroscopy to determine several chemical and biological parameters of pastures under the agroclimatic conditions of the Azores, and to compare its predicative ability when applied to dry homogeneous samples and to fresh inhomogeneous samples, so that we can assess the feasibility of using it to predict new samples on-site in the future. Infrared spectra of 400 fresh and dried grass samples were collected and associated with the corresponding reference values, determined through conventional methods. Mathematical models were created that established relationships between these readings and the values of the properties of interest. Predictive capacity proved especially good for crude protein, neutral detergent fiber, acid detergent fiber, ash, and dry matter, but insufficient for the biological parameters included in the study related to gas production. Near-infrared spectroscopy proved to be useable on-site as a quick, non-destructive, and cost-effective technique to monitor forage quality on a regular basis, enabling forage management and diet design optimizations.

This work aimed to determine and compare the effect of elevation and season on the productivity and the nutritive value of pastures in the Azores (Terceira Island). Forage was collected and analysed for dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), ether extract (EE), mineral ash (Ash), dry matter digestibility (DMD) and organic matter digestibility (OMD). The net productivity (NP) was higher in the low elevation pasture A (1.80 g m−2), lower in pasture B (0.98 g m−2) and peaked in the winter in both pastures A (3.57 g m−2) and B (2.33 g m−2) and during the summer in the high elevation pasture C (2.15 g m−2). The soil chemical proprieties varied significantly among the three pastures. The highest soil pH, available P, K, Ca and Mg were recorded in pasture A. Positive correlations were observed between all soil parameters analysed and NP, except for the OM content. The DM, PB and EE changed significantly with elevation, while all nutritive parameters (except CP, EE and Ash) increased significantly along the growth season. Environmental factors influenced the nutritive parameters and productivity, suggesting that climate change might have significant impacts on forage production and quality.

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Livestock production is the main economic engine of the Azores. Given the role nutrition plays in animal performance and the context of limited Averages sharing the same letter are noagricultural area of the archipelago, optimising the quality and availability of the fodder used in feeds takes on an important role in increasing the competitiveness and viability of the industry. This work evaluated the potential of NIR spectroscopy to quantify several chemical and biological parameters used to assess silage quality in the specific agroclimatic context of the Azores. Reference values were determined for 400 grass silage and 400 corn silage samples. The corresponding NIR spectra were extracted, and mathematical models capable of correlating these readings with the various parameters were built. The best results were obtained for crude protein, neutral detergent fibre, acid detergent fibre, and crude ash for both fresh and dry samples. For the biological parameters concerning gas production, no satisfactory results were reached. It was concluded that it was feasible to build models capable of accurately predicting these important quality parameters, which demonstrates that NIRS is a viable technique that can be used in the Azores to perform a close and timely monitoring of forage quality and to facilitate the management and optimisation of diets.

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