PSII-3 Effect of Room Temperature Regimen on Growth Performance and Mortality of Newly-Weaned Pigs

Abstract

Abstract Current recommended room temperatures for newly weaned pigs are based on historical research carried out several years ago. Since that time, major changes have occurred in the genotype of the pigs and in the management and the housing environment. This study was carried out to determine if a temperature regimen based on the choice of temperature of the pigs would improve post-weaning performance of pigs of different weaning weights. This study was carried out over the first 4 weeks after weaning (21 ± 1 d) using a split-plot design with 2 treatments: 1) Room Temperature Regimen (RT; main plot; Preferred vs. Control); 2) Weaning Weight (WW; subplot; Light vs. Heavy). Room temperatures for the Preferred treatment were 32, 32, 30, and 28℃ for wk 1, 2, 3, and 4 of the study, respectively. Room temperatures for the Control treatment (based on current recommendations) were 28, 26, 24, and 22℃ for week 1, 2, 3, and 4 of the study, respectively. The WW treatments were based on the lightest and heaviest pigs, respectively, from each litter. Four identical rooms of a wean-to-finish facility were used (2 rooms/RT treatment); 256 newly weaned pigs were housed in mixed-sex pens of 8 (16 pens/RT treatment) at a floor space of 0.78 m2/pig. Growth performance (ADG, ADFI, G:F) and mortality were measured over the 4-wk study period. The average start and end weight was 4.6 ± 0.32 kg and 12.7 ± 0.89 kg, respectively, for the Light WW treatment and was 6.4 ± 0.40 kg and 15.8 ± 1.47 kg, respectively for the Heavy WW treatment. There were no interactions (P > 0.05) between RT and WW for growth performance measures. There was no effect (P > 0.05) of RT on overall growth performance. Light WW pigs had less (P < 0.05) overall ADG (0.29 vs. 0.34 kg; SEM 0.009) and ADFI (0.40 vs. 0.46 kg; SEM 0.010) but similar G:F (0.733 vs. 0.739 kg; SEM 0.0115) compared with Heavy WW pigs. There was an interaction (P < 0.05) between the RT and WW treatments for overall mortality. There was no effect (P > 0.05) of RT for Heavy WW pigs (3.1 vs. 1.6 % for the Preferred and Control treatments, respectively; SEM = 1.89); however, mortality was less (P < 0.05) for Light pigs on the Preferred than on the Control treatment (1.6 vs. 7.8 %, respectively; SEM 1.89). In conclusion, the Preferred RT treatment did not impact growth performance in the first 4 weeks after weaning but reduced mortality of pigs of light, but not heavy weaning weight. This finding warrants verification under commercial conditions.