NEW TECHNOLOGICAL AND NUTRITIONAL APPROACHES IN LIVESTOCK FARMING

The livestock sector is facing a huge challenge trying to meet the increasing demand of animal products. To this end several efforts have been done to enhance animals\u2019 performances, and nutrition provides a valuable asset. Animals\u2019 performances can indeed be boosted through nutritional approaches, including both the application of technologies in a context of \u2018precision nutrition\u2019 and the administration of novel feed additives or feedstuffs with beneficial effects on animals\u2019 health. The main aim of this thesis was to investigate 1) the proficiency of feeding systems for dairy cows (1st trial) and the suitability of sensor technology to ensure the fulfillment of cows\u2019 nutrients requirement (2nd trial), and 2) the effectiveness of feed additives to improve animals\u2019 health and consequently their performances (3rd and 4th trial). The first study investigated some aspects connected to the mixer wagon, and their influence on the preparation of the total mixed ration (TMR) for dairy cows. We evaluated how loading levels, cutting time, mixing time and their interaction can affect the homogeneity of the TMR along the feeding alley. The uneven distribution of the TMR along the feeding alley does not allow each animal to receive the same well-balanced diet, with the risk of not satisfying the nutritional requirements, finally impairing productive performances. Even though we identified the most efficient combination of loading levels, cutting, and mixing time, variations in the distribution of DM and NDF were observed, pointing out the necessity to investigate which other factors are influencing TMR preparation and distribution. In the second study we developed a system based on a microwave resonance sensor to optimize TMR preparation. Silages represent a large proportion of feeds included in the TMR, but their nutrient supply (on as fed basis) can vary among time due to moisture content fluctuations. For this reason, if their inclusion rate in the mixer wagon is not adjusted according to the actual dry matter (DM) content, ensuring the proper provision of nutrients, the delivered TMR might be different from the diet formulated by the nutritionist, with the risk of unfulfilling animals\u2019 requirement. The sensor performed a real-time measurement of silages DM content during their loading in the mixer wagon and suggested a correction of their inclusion rate. Our hypothesis was that, adjusting the silages as fed inclusion rate according to the real DM content, the final TMR delivered to the animals would have been closer to the target diet. The employment of the sensor reduced the error in silages DM content loads, however the final TMR was not closer to the formulated diet compared to the TMR conventionally prepared. The lack of result was attributed to errors in the loading of dry feedstuffs (concentrates), which can equally affect TMR composition. Our results thus highlight the necessity of systems to improve the accuracy of TMR preparation. The third study was dedicated to the evaluation of the effectiveness of pomegranate rinds and green tea leaves extract on broiler chicken health and performances. We assessed the potential of the product to improve blood antiradical activity, as a way to increase animals\u2019 defence against oxidative stress. We further investigated the effect on cecal microbiota, observing a positive modulation of beneficial bacterial population, such as Lactobacillaceae. Despite the positive results observed for health-related parameters, growth performances were not enhanced. Lastly, in the fourth study we investigated the effect of nucleotides supplementation to weaning piglets. Nucleotides play a fundamental role in the development of gastrointestinal mucosa and immune system, but due to the high demand in critical moments (i.e. weaning) and the reduced de novo synthesis, their supplementation might be beneficial for the animals. However, we did not observe positive effect of nucleotides supplementation on animals\u2019 immune response, probably due to the optimal conditions where the animals were raised, which minimized the stress usually associated with weaning. Overall, these results contributed to the investigation of technological and nutritional approaches to improve the efficiency of animal feeding. However, further investigations are required to deepen our knowledge about the limitations that have been observed