Microbiological assessment of liquid feed for finisher pigs on commercial pig units

Aims To investigate the microbiological and nutritional quality of liquid finisher pig feed on commercial production units and the factors influencing this. Methods and results Microbiological and physio-chemical analyses were performed on liquid feed sampled from the mixing tank and troughs of the finisher section of eight commercial pig units. Lactic acid bacteria, yeast andEscherichia colicounts, as well as lactic acid, ethanol and acetate concentrations were higher in residual feed sampled from the troughs compared with mixing tank samples (P < 0 center dot 001). Feed pH, as well as lysine, methionine and threonine concentrations and gross energy were all lower in the residual trough samples (P < 0 center dot 001). Liquid co-products reducedE. colicounts in the residual trough samples (P < 0 center dot 05), pH in the mixing tank (P < 0 center dot 01) and fresh trough samples (P < 0 center dot 05) and mould counts at all three sampling locations (P < 0 center dot 01) but sanitation practices had no impact. Conclusions Even when considered unfermented, a considerable degree of spontaneous fermentation occurs in liquid feed, with resultant negative effects on nutritional quality. Significance and Impact of the Study This is one of the first studies showing that uncontrolled fermentation of fresh liquid pig feed is commonplace on commercial units, highlighting the need for implementation of suitable control strategies.

Automated summary

This study investigates the microbiological and nutritional quality of liquid finisher pig feed on commercial production units and finds that uncontrolled fermentation negatively affects the nutritional quality. The study highlights the need for suitable control strategies to manage fermentation in liquid pig feed on commercial units.