A study of 66 producitives pigs files belonging to 7 years of farm production was analyzed. The objetive was to find the relationship between maternity mortality and the number of days up to sale.
The best fits a cuadratic model with two independent variables: 1) X maternity mortality and 2) Sale wigth, (R² = 0.36): it shows that the sale days decrease while the mortality increases, since it should be alive the stronger animales, but it is until a value where again the sale days increase, it can be inputed that it is not a problem of individual pigs but to a problem in the litter. Although, no statistics differences were found there is a effect of the birth month onto sale days, with pigs born in april and may presenting a longer delay and pigs in summer month, showing an increase in the use of the energy for mantaining body temperature in the former pigs and a decrease in the food intake in the latters.