Processing wilted alfalfa with crop processing rolls on a pull-type forage harvester

Crop processors on forage harvesters have become readily available and widely used by North American livestock producers. Past research has shown that intensive mechanical processing at the time of cutting can improve the fiber digestibility of alfalfa and grasses, and questions have surfaced as to the potential effectiveness of a crop processor on a forage harvester to also improve the animal utilization of wilted forages. Processing wilted alfalfa with crop processing rolls was effective in increasing the level of plant tissue disruption, as quantified by leachate conductivity, by more than 30% in all cases and similarly reduced particle-size from the theoretical-length-of-cut. Processed material was visibly darker and more bruised than control treatments. Processor roll clearance and cutterhead theoretical-length-of-cut had a greater effect on crop physical properties than did processing roll speed difference. Processing wilted alfalfa increased harvester energy requirements by 36 to 113% depending upon crop moisture and the feeding characteristics of the processing rolls as affected by the aggressiveness of the tooth profile. Processing wilted alfalfa increased the crops in situ dry matter disappearance at 12 and 24 h by greater than six percentage units and increased the instantly soluble fraction by up to seven percentage units. However, processed alfalfa did not affect lactation performance of Holstein dairy cows

Processing whole-plant corn silage with crop processing rolls on a pull-type forage harvester

Whole-plant corn silage (WPCS) was harvested with a pull-type forage harvester equipped with crop processing rolls. Variables considered were crop maturity, theoretical length-of-cut (TLC), processor roll speed difference and roll clearance. Whole-plant particle size, whole cob and coarse fiber fractions, level of kernel breakage, and kernel fraction particle-size were used to quantify crop physical properties. Compared to unprocessed WPCS cut at 9.5 mm TLC, WPCS cut at 19 mm TLC and then processed had greater whole-plant particle size, less whole cob fraction, fewer unbroken kernels, smaller kernel fraction particle size, and greater estimated surface area of the kernel fraction. The processed treatments at 19 mm TLC and 3 or 5 mm roll clearance required similar specific energy and produced similar harvesting rates compared to the control unprocessed treatment at 9.5 mm TLC. Feeding dairy cattle WPCS (approximately 33% of DMI) increased fat-corrected milk yield by about 4% and fat yield by about 2%. Compared to unprocessed WPCS cut at 9.5 mm TLC, WPCS cut at 19 mm TLC and processed with 1 mm roll clearance increased in situ DM disappearance by seven percentage units. Based on crop physical properties, harvester energy requirements and dairy cattle lactation performance, the recommended settings when harvesting WPCS with an on-board crop processor would be 19 mm TLC and 1 to 3 mm roll clearance

Analysis of Airflow Field of Toss Device of Yellow Corn Forage Harvester

International audienceUse a very important tool called ICEM CFD integrated in ANSYS Workbench to mesh the model of toss device and then apply the software FLUENT to simulate numerically and analyze the velocity distribution and pressure distribution, based on the RNG k-epsilon model. Numerical simulation results showed that air flow field and pressure distribution of toss device were asymmetry. Maximum wind speed of fan exit was 42.8 m/s, which met the actual needs. In a word, the design of toss device was reasonable. But there was the existence of the secondary flow in toss cylinder, making some gas couldn’t flow smoothly, thus affecting delivery efficiency. Through analysis of the stress field in the blower, the results showed that static pressure of windward side blade increased from roots to ends and flow channels between fan blades in different positions showed different static pressure characteristics. The maximum static pressure of windward side blade was 878 pa, the minimum static pressure of lee side blade just passing the export of fan was -950 pa, the negative pressure meaning suction. The conclusions provided a reference for structural optimization and performance improvement of the toss device of Yellow Corn Forage Harvester

Uso de volumosos conservados na alimentação de equinos Use of conserved roughage in the horse feeding

Revisão de artigos sobre características e uso de forragens conservadas na alimentação de equinos, considerando o bem estar animal e ressaltando a necessidade de integrar a atual tecnologia do uso, fisiologia, manejo e nutrição animal. Um ponto básico e critico no manejo alimentar de equinos é a disponibilidade de forragens de alta qualidade para uso como pastagens, ou forragens conservadas na forma de fenos e silagens. Os mais tecnificados sistemas de produção animal adotaram o feno para alimentação e este é o motivo pelo qual grande parte dos artigos científicos relativos à nutrição de equinos usou o feno como volumoso. Silagens são adotadas em alguns sistemas, porém poucos artigos técnicos estão disponíveis avaliando seu uso na nutrição de equinos. Devido às características anatômicas e fisiológicas, o equino deve receber grandes quantidades de forragem e a taxa de fornecimento deve permitir a seletividade da captura e fácil ingestão da forragem. Para qualquer volumoso, o perfil nutricional deste é diferente quando oferecido na forma de pastagem ou forragem conservada, situação atribuída a seletividade e individualidade animal bem como a variação nas partes da planta. Paralelamente com o conhecimento da composição nutricional e manejo de conservação de forragem, especial atenção deve ser dada as condições ambientais de alojamento e restrição de movimentos dos animais. O planejamento de atividade física para o equino conjuntamente com o manejo adequado ajuda a prevenir problemas que afetam animais que não tem acesso a pastagem. Os fenos, silagens e pré-secados, usados quando a pastagem não é disponível, divide com o concentrado o maior número de casos de problemas de saúde. Cólica, acidose, laminite, consumo de palha e madeira estão associados a deficiências nutricionais, desconsiderando erros humanos e condições ambientais desapropriadas. Informações técnicas para melhor entendimento sobre o consumo animal em qualidade, quantidade e/ou a forma que o alimento é fornecido, vem sendo responsável pelo desempenho positivo e bom manejo de equinos mantidos em sistemas que o privam de acesso a pastos e atividades físicas.<br>This text revised some papers in literature about characteristics and use of conserved forages for horse feeding, considering animal behavior and outstanding the need of programs that could integrate the current knowledge of use, physiology, management and animal nutrition. A basic and critical nutritional condition for equine management is the availability of high quality forage for use as pasture or conserved as hay or silage. Most professional horse production systems adopt hay for animal feeding and this is why most available scientific papers regarding horse nutrition uses hay as roughage. Silages are adopted in some systems, but a smaller number of studies are available in technical literature evaluating his use in horse nutrition. Due to their anatomic and physiological characteristics, horses should be given high quality pastures and stocking rates must allow selectivity in forage capture and easy ingestion. For any forage, the nutritional profile is different if offered to animals used as pasture or conserved, due selectivity, plants part and variation among horses. Besides the analytical results of feeds and conservation processes adopted, special attention should be given to the environmental conditions of animal kept in stables or with restricted movements. A physical activity plan for horses and adherence to appropriate routines help preventing problems that affect animals without access to pasture. The hays, silages and haylages used as substitutes when pasture is not available, share with concentrates the highest position as causes of health problems. Colic, acidosis, laminitis, straw and wood consumption are associated to nutritional deficiencies, without considering human mistakes and inappropriate environmental conditions. Technical information for better understanding of animal consumption in quality, quantity or the way food is offered, has been responsible for the positive performance and good management in systems that deprive their access to pastures or physical activities