Genetic Potential for Growth, Feed Conversion and Longevity

The purpose of this study was to find out genetic potential for growth, and feed conversion coefficient in pigs. It was done by analysing the relationship between variables that are relevant to animals' development, namely the growth rate, feed conversion coefficient, and live weight. The study entails a hybrid dynamic mathematical model of the traits studied. The model is a species-specific concept, it was built for growing domestic pigs. Pigs are well-known model animals in human physiology. Some physiological factors are reportedly control both growth and ageing. Growth hormone and insulin-like growth factor-1 are reportedly the factors, which modulate growth, aging, and body size in mammals. The model does not entail growth hormone and insulin-like growth factor-1 as variables. However, the study demonstrates nonlinear dynamic of relevant variables in domestic pigs from 30kg up to 600kg. The model was constructed by considering functional relations between variables analysed in experiments and field observations. Theoretical notions about growth processes as a dynamic system are included in the model. An invariant of growth dynamic is introduced. The study suggests that growth, feed conversion, and life span are functionally related traits in domestic pigs. In the pig, longevity is a function of growth rate and feed conversion coefficient. The novelty of the study is a method for the investigation of genetic potential for growth, and longevity in pigs. In the model, genetic potential for growth rate and feed conversion were identified by analysing functional relations between relevant variables. The concept supports the opinion that growth, and ageing are interrelated processes.