Avaliação do comportamento ingestivo utilizando eletromiografia de superfície do músculo masseter

Physiologists and animal scientists try to understand the relationship between ruminants and their environment. The knowledge about feeding behavior of these animals is the key to maximize the production of meat and milk and their derivatives and ensure animal welfare. Within the area called precision farming, one of the goals is to find a model that describes animal nutrition. Existing methods for determining the consumption and ingestive patterns are often time-consuming and imprecise. Therefore, an accurate and less laborious method may be relevant for feeding behaviour recognition. Surface electromyography (sEMG) is able to provide information of muscle activity. Through sEMG of the muscles of mastication, coupled with instrumentation techniques, signal processing and data classification, it is possible to extract the variables of interest that describe chewing activity. This work presents a new method for chewing pattern evaluation, feed intake prediction and for the determination of rumination, food and daily rest time through ruminant animals masseter muscle sEMG signals. Short-term evaluation results are shown and discussed, evidencing employed methods viability.

A altura de dossel e a adubação nitrogenada da pastagem podem afetar a nutrição nitrogenada do milho, num sistema de integração lavoura pecuária?

We conducted a field experiment near Abelardo Luz, Santa Catarina, from October 2012 to April 2014, to evaluate the effect interaction of nitrogen fertilization and height of canopy over the N nutrition of corn subsequently grown to pasture. The data belonging to this thesis are related to the first two production cycles obtained in sorghum pasture (2012/2013), oat (2013) and corn crop (2013/2014). In the evaluation of forage sorghum and oat it was used the same experimental design, consisting of randomized complete block in a factorial arrangement (2 x 2) with three replications. The first factor was considered canopy height (Low and High) and the second factor was the fertilization of cover crop pasture (0 and 200 kg N.ha-1). In phase I and II, the combination of factors evaluators were prepared in the same experimental unit. For corn crop the design was a randomized complete block in a factorial design (2X2X4X6) with three replications. Factors considered in corn were: canopy height of pasture (Low and High), nitrogen application times (NG - nitrogen in the grains and NP - nitrogen in pasture), nitrogen fertilization in corn (0, 100, 200 and 300 kg N.ha-1) and time (46, 53, 60, 67, 76 and 103 days after sowing the maize). In phases I and II, in general the use of N in the pasture increased the productive potential of the pasture and animal management and canopy height has changed the dynamics of structural components and botanical pasture. In cold conditions for long periods and not acclimatized plants the adoption of high nitrogen fertilization and height high grazing pasture leave vulnerable to damage caused by the freezing of plants. The anticipation of nitrogen fertilization on pasture positively affects the corn crop by increasing the accumulated dry matter and N content in the plant. Nitrogen nutritional content of corn with the anticipation of fertilization in pasture is suitable for obtaining high crop production in integrated crop-livestock system. When used nitrogen only coverage in corn sufficiency level in the nitrogen nutrition is achieved with the use of 100 kg N.ha-1. With the use of 200 kg N ha -1 NG and NP no difference in nitrogen content and nitrogen nutrition index.