1,721,013 research outputs found
AUTOMAZIONE DELLA PREPARAZIONE E DISTRIBUZIONE DI RAZIONI COMPLETAMENTE MISCELATE (TMR) O UNIFEED PER BOVINE DA LATTE: POSSIBILITA' TECNOLOGICHE E RICADUTE PRODUTTIVE, GESTIONALI ED ECONOMICHE
Full text linkFeeding Total Mixed Rations (TMR) has become a common practice for dairy cows as a result of the benefits for the animals and the labour savings for farmers. Characteristic for this feeding system are the man-operated mechanical mixers. Besides the advantages of the TMR technique, it has the same drawback as most traditional ad-libitum feeding systems that the discharge of feed is limited to once, maximum twice a day. During the last 5-8 years, technologies for automatically feeding cows with TMR have grown in popularity. Almost 20 manufacturers are working worldwide on different designs for automatic feeding systems (AFS) while an estimated 400-500 farms have adopted this technology, mostly located in Northern Europe, Canada and Japan. The different manufacturers offer a wide range of technical solutions. Some of the most important aspects that characterize these systems include the possibility of a high frequency to distribute the ration, to control the feeding times, to stimulate the cow activity and to manage the composition of the total daily ration with the objective to control the feed intake. The management possibilities and the quality of work seem to be strongly affected by the concepts of the technical solutions that are now available. The thesys discusses, in Chapter 1, the physiologic aspects affecting the possibility of mechanize the feeding operations of dairy cows. In Chapter 2 the different automatic feeding technolgies have been analyzed and classified for the first time. In Chapter 3 the results of a survey involving the Wageningen University and carried out in 22 Dutch farms that use automatic systems for milking and feeding cows have been described. In Chapter 4 an assessment of the main functional parameters of AFSs such as mixing uniformity, physical composition of the ration and cows behaviour has been reported. In Chapter 5 the thesis reports the economic analisys related to the introduction of AFS and the first problems encountered leading to propose further research actions
L'automazione dell'unifeed e le tecnologie disponibili
No full textL'introduzione di sistemi automatici per la preparazione e la distribuzione delle razioni unifeed per bovine da latte avvenuta negli ultimi 5-8 anni in alcuni Paesi Nord Europei ed in Canada, consente di attivare nuove strategie di alimentazione. Viene presentata una panoramica delle diverse tecnologie oggi presenti sul mercato
Performance of a modern sprayer control unit in severe operating conditions
No full textThe modern systems for controlling the spraying rate are based on a computer driving the distribution valves, in order to increase (or decrease) the flow rate proportionally to the travelling speed variations of the sprayer. In this way, the spatial rate of the pesticide distributed on the crop should be (relatively) constant inside of a wide range of travelling speed values. The central unit is a computer, normally operating with: - one or more flow meters, to measure the rate passing through given sections of the hydraulic circuit; - a pressure gauge, to control the pressure values of the flow after the control of the distribution valves; - some magnetic sensors, a radar or other systems to measure the tractor-sprayer travelling speed
A retrofit variable-rate control system for pressurized slurry tankers
Full text linkn the last several decades, livestock effluent management practices and field slurry spreading operations have received increasing attention due to their economic and environmental implications. In this study, a variable-rate control system for pressurized slurry tankers was developed according a retrofit approach (i.e., as a self-standing module that can be adapted and mounted on existing slurry tanker equipment). The system provides farmers with a useful tool for achieving compliance with environmental protection regulations and for developing good practices for livestock and nitrogen management. This system is suitable for new and used pressurized tanker equipment. For field-testing purposes, this system was mounted on a double-axis 10 m3 slurry tanker equipped with a crawling nozzle distribution unit. Field experiments were conducted at two typical forward speeds (2 and 3 km h-1) and three different nitrogen application rates (170, 250, and 340 kg ha-1). Based on the experimental results, the system was generally capable of limiting the differences between the nominal and measured application rates to less than 9%. In addition, the data analysis indicated that the slurry spreading was not significantly affected by the forward speed of the tanker. The uniformity of nitrogen spreading was evaluated according to the UNI EN 13406:2002 standard. The results showed that the transverse field distribution was uniform throughout the working width of the machine and at all tested operating conditions, with maximum deviations that were limited to less than 15%
Automazione dell’unifeed : l’evoluzione continua
No full textI carri miscelatori azionati dall'operatore sono macchine che hanno permesso la larga diffusione della tecnica unifeed. Recentemente, sono apparsi sistemi automatici per la preparazione del piatto unico che permettono di intravvedere prospettive inedite, dall'organizzazione del lavoro, alle sinergie con i sistemi automatici di mungitura fino alla razionalizzazione del comportamento e del benessere degli animali
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