Chewing behaviour of growing cattle
Chewing behaviour includes both eating and ruminating activity. Chewing behaviour is of great importance for the feed intake as through the action of chewing (i.e. eating and ruminating) animals mechanically process the forages in small particle sizes and prepare the food for digestion. As cattle grow the chewing behaviour changes along with increasing body weight and chewing efficiency is increased. The aim of this thesis was to review the available scientific literature in order to describe chewing behaviour in growing cattle, as well as the factors that affect this behaviour. The processes of eating and ruminating have different functions with regards to the particle size reduction. Eating prepares the food for swallowing and ruminating reduces the size of the intractable material. The literature that is reviewed in this thesis suggests that chewing behaviour is affected by a number of aspects, such as maturity stage of the forage at the time of harvest, fibre content of the animal feed and feed particle size. In growing cattle changes are observed in chewing duration, most likely due to physiological development (i.e. growth) of the animal. Bite and rumination efficiency increases with age and body weight in cattle. Various methods and techniques are used in determining chewing behaviour of cattle. Information provided in this thesis suggests that these techniques aim to monitor the different frequencies and patterns of jaw movements. Although chewing behaviour of ruminants is well documented in the literature, limited information is available on the aspect of modelling the eating and rumination behaviour of ruminants. In addition, as there are some opposing findings in relation to the duration of chewing time in growing cattle, more research is required to clarify this.