A case-study of fattening pigs in Belgian contract farming. Mortality, efficiency of food utilization and carcass value of growing pigs, in relation to environmental engineering and control

Abstract

Mortality, efficiency of food utilization and carcass value of growing pigs were investigated in relation to engineering and control of the house environment. Data originated from contract farms and were made available by the Belgian Farmers' Association. The following parameters were investigated by means of analysis of variance and covariance: food conversion ratio, mortality, emergency slaughter rate and carcass values. Data were classified according to characteristics of the heating, air inlet and air outlet systems of the pig houses.Within the limitations of our project, the expected favourable effect of heating on mortality and efficiency of food utilization of growing pigs depended on the construction and the functioning of the air inlet and outlet systems. Pigs fattened in houses with mechanical ventilation had a higher proportion of carcasses in the higher carcass grades. Seasonal effects were observed with respect to mortality rate, emergency slaughter rate and efficiency of food utilization. Differences between food conversion ratio with respect to heating and no-heating were comparable with those between summer and winter conditions. Hence the seasonal influence was not completely buffered by the housing conditions.