Effects of the density by pen on production and the concentration of blood metabolites and cortisol in growing and finishing pigs

Abstract

THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE EFFECT OF REDUCING AVAILABLE FL OOR SPACE, DUE TO AN INCREASING NUMBER OF PIGS PER PEN ON AVERAGE DAILY FEED CONSUMPTION (ADFC), DAILY GAIN (ADG) AND FEED EFFICIENCY (FE) AND THE BLOOD CONCENTRATIONS OF GLUCOSE, UREA AND CORTISOL IN GROWING AND FINISHING PIGS. ONE HUNDRED AND TWENTY GROWING PIGS AND 64 FINISHING PIGS WERE RANDOMLY ASSIGNED TO 3 DENSITIES: 1) = ONE PIG INDIVIDUALLY ALLOCATED WITH 2.5 M2 OF AVAILABLE SPACE; 2) = SIX GROWING OR FOUR FINISHING PIGS WITH 0.94 AND 1.41 M2 OF AVAILABLE FL OOR SPACE PER PIG; AND, 3) = 12 GROWING OR EIGHT FINISHING PIGS WITH 0.47 AND 0.71 M2 OF AVAILABLE FLOOR SPACE PER PIG. THE SERUM CONCENTRATIONS OF GLUCOSE, UREA AND CORTISOL WERE DETERMINED AT THE BEGINNING OF THE EXPERIMENT AND AT THE END OF WEEKS 1, 3 AND 5. IN GROWING PIGS, ADFC (P < 0.05) AND ADG (P < 0.10) WERE GREATER FOR DENSITY 1 THAN FOR DENSITIES 2 AND 3; FE WAS GREATER (P < 0.10) FOR DENSITY 2 THAN FOR DENSITIES 1 AND 3. IN FINISHING PIGS, ADFC AND ADG (P < 0.10) WERE GREATER FOR DENSITY 1, THAN FOR DENSITIES 2 AND 3. THE GLUCOSE, UREA AND CORTISOL CONCENTRATIONS WERE NOT DIFFERENT AMONG DENSITIES. FEED INTAKE AND WEIGHT GAIN WERE REDUCED AS DENSITY PER PEN INCREASED; HOWEVER, THE REDUCTION IN PERFORMANCE WAS NOT RELATED TO CHANGES IN THE SERUM CONCENTRATION OF SOME STRESS INDICATORS SUCH AS GLUCOSE, UREA OR CORTISOL.