Conductive cooling of group-housed grow-finish pigs: Year 1

The goal of this research is to enhance the energy efficiency of pigs by using floor tempering as a means of mitigating the impact of seasonal thermal stress on pig performance. The specific objectives of this study were to measure the effects of providing cooled floors for group-housed grow-finish pigs during the summer months on average daily feed intake (ADFI), rate of gain (ROG), and feed efficiency (gain:feed). The study was conducted in specially-designed rooms with partially slatted pen floors, wherein floor temperature control of the solid-floor portion of the pens enabled conductive cooling of pigs. Groups of four to five pens (zones) in a room, with 15 mixed-sex pigs/pen were controlled simultaneously. Two trials were conducted in the summer of 2017 and provided the first set of data in a long-term study. Pigs in Trial 1 started in early April of 2017 with an average body weight of 20.4 kg (c.v. 0.005) and ended in July at 111 kg (c.v. 0.029). Treatments of no cooling (control) and cooling (temperature setting based on room temperature setpoint and dewpoint temperature during three of five feed phases) were applied to two zones with five pens in each zone. Trial 2 pigs started in early May at 21.5 kg (c.v. 0.005) and finished the trial in August at 107 kg (c.v. 0.030). In Trial 2 there were two zones each of no cooling and cooling (temperature setting based on room temperature setpoint and dewpoint temperature during three of five feed phases), with four pens per zone. Individual pig weight was measured at the start of the trial and at each feed phase change. Feed additions to each pen were weighed and summed for each phase. Numerically, pigs raised on the cooled floors were 2 to 3 kg heavier at the end of each trial and consumed more feed faster than the pigs with no cooling. The ADFI was higher over Trial 2 (p<0.1) for pens with floor cooling and increased faster over each feed phase with floor cooling (p<0.1 in Trial 1; p<0.01 in Trial 2). ROG and gain:feed were not significantly affected (p>0.1) by the floor conditions in the limited replications thus far. Additional replicates and floor temperature control schemes are expected to further strengthen treatment results over the long term.