5 research outputs found
A Dynamic Optimisation of Summer/Autumn Feeding Strategies for Wool Production in the Mediterranean Environment of Western Australia
To counteract declining quantity and poor quality of paddock feed over summer/autumn, farmers in Western Australia must decide how much of which supplement to provide to grazing sheep to optimise the use of supplements. The solution is complicated by the interaction of biological and economic factors and the intertemporal nature of the problem. A dynamic programming approach was used to determine optimal feeding strategies for different starting conditions. Lupin seed was preferred to oats for weaners when paddock feed was abundant, while oats was preferred for weaners and adults when paddock feed was scarce. The optimal feeding rate usually starts low and then gradually increases to higher rates as the autumn break approaches.Livestock Production/Industries,
A Dynamic Optimisation of Summer/Autumn Feeding Strategies for Wool Production in the Mediterranean Environment of Western Australia
To counteract declining quantity and poor quality of paddock feed over summer/autumn, farmers in Western Australia must decide how much of which supplement to provide to grazing sheep to optimise the use of supplements. The solution is complicated by the interaction of biological and economic factors and the intertemporal nature of the problem. A dynamic programming approach was used to determine optimal feeding strategies for different starting conditions. Lupin seed was preferred to oats for weaners when paddock feed was abundant, while oats was preferred for weaners and adults when paddock feed was scarce. The optimal feeding rate usually starts low and then gradually increases to higher rates as the autumn break approaches
Fabric-evoked Prickle in Worsted Spun Single Jersey Fabrics Part 4: Extension from Wool to Optim TM
Biological control of mosquito populations: An applied aspect of pest control by means of natural enemies
Avanços metodológicos na determinação do consumo de ruminantes em pastejo Advances in methods for determining animal intake on pasture
Avanços metodolĂłgicos sĂŁo, usualmente, conseqĂĽĂŞncia direta de avanços conceituais e tecnolĂłgicos. No caso da estimativa do consumo em pastejo, os recentes avanços conceituais relativos ao processo de busca e apreensĂŁo da forragem pelo ruminante evidenciaram a importância da unidade básica do consumo o bocado -, e dos fatores limitantes ao consumo que ocorrem antes da ingestĂŁo da forragem pelo animal em pastejo. A abordagem reducionista do processo de pastejo, aliada Ă sua hierarquização espaço-temporal, trouxeram uma nova concepção de como o animal obtĂ©m o seu alimento do pasto. Destes modelos conceituais emergiram novas variáveis que requerem novos procedimentos experimentais e analĂticos. Neste contexto, importantes avanços tĂŞm ocorrido. Este artigo apresenta e discute os novos procedimentos que permitem estimar o consumo no curto prazo, assim como aqueles mais utilizados pela comunidade cientĂfica nacional para estimar o consumo no longo prazo. Adicionalmente, sĂŁo feitas tambĂ©m considerações sobre o uso de animais ou de piquetes como unidades experimentais em experimentos de pastejo. Conclui-se que, apesar de ainda existir importantes barreiras metodolĂłgicas, os recentes avanços conceituais sobre o processo de pastejo, assim como dos procedimentos analĂticos, geram fortes expectativas de avanço em curto e mĂ©dio prazo na obtenção de estimativas qualificadas de consumo por animais em pastejo.<br>Methodological advances are usually a direct consequence of conceptual and technical advances. In the case of animal intake on pasture, recent conceptual advances regarding the process of searching and apprehension of the forage by the ruminant provide insight regarding the importance of the basic unit of intake, the bite, and the importance of processes limiting intake that occur before the forage reaches the rumen. Applying a reductionist approach to the grazing process, along with its spatial-temporal hierarchy, brought a new conceptualization of how an animal obtains feed from pasture. From the conceptual models emerged new variables that required new experimental and analytical procedures. Within this context, important advances have occurred. This article describes the new procedures that allow to estimate the consumption on the short-term, as well as that most utilized by the national scientific community for estimating the consumption on the long-term. Procedure for estimating fecal production and digestibility are discussed, as well as the use of n-alkanes and other emerging techniques. Consideration is given to the use of animals or paddocks as experimental units in grazing experiments. The conclusions presented in this article do not differ from those of preceding articles regarding this subject. In a grazing condition, continuous intake is the "black box" to be revealed, complex by nature with regard to the animal as well as the pasture, and there are important methodological barriers toward is determination. Nevertheless, recent advances in conceptualizing the grazind process, as well as in the analytical procedures, have been considerable and generate ambitious expectations over the short and long term