Prevalence, causes and prevention of bruises in Chilean beef cattle at slaughter, and its implication for animal welfare

The main objective of this research is to identify and quantify generic measures that indicate the capability of individual animals (at a particular moment) to cope with (infectious) disruptions. This is referred to as the resilience, or more precisely the precariousness, of individual farm animals and it will be quantified by describing the dynamics of one or more physiological variables (referred to as biomarkers) which can be measured easily and repeatedly in growing piglets.

The hypotheses that will be tested in this research are:

1. There are biological variables within the complex system of an animal that can be used as indicators for the resilience concept of precariousness and can be measuredcontinuously during (long) periods of the life time of an animal

2. The continuous dynamic signal of this indicator can be analysed and modelled so that the characteristics of the biomarker can be assessed.

3. The biomarker varies in time and between animals, and has a predictive value with respect to the ability of the animal to respond to infectious disturbances and other perturbations.

4. The theory of critical slowing down as assessed by Scheffer et al., (2009) on population dynamics can be applied to individual animals. Precariousness is reducedwhenever critical slowing down is approaching, meaning that it is more difficult for these animals to adapt after only small perturbations.