Incidence of heating the liquid feed on performance of fattening pigs

Eric Royer et al., 70th Annual meeting of the European Federation of Animal science (EAAP), 26-30 août 2019, Ghent, Belgique, p. 415

Pig farms producing their own renewable energy could improve animal health or performance by the controlled heating of liquid feed. This study evaluated the effects of different liquid feed temperature on performance of growing-finishing pigs. For the fattening period (27.5 to 112 kg), a total of 144 pigs received, according to plan, a growing then a finishing diet mixed with water in a ratio of 2.8:1 l/kg and distributed at 10, 20 or 30 °C. Pigs of each treatment were allocated to 8 pens of 6 animals each, spread throughout the liquid feeding facility and received 13 times per week a liquid feed distributed by an automated supply system. Environmental temperature was maintained at 24 °C during the whole period. After distribution, pigs fed the 30 °C meal ate faster than pigs delivered 20 or 10 °C meals. It was visually observed that the latter ones agitated the mixture before eating. From d 0 to 52, pigs receiving 30 °C meal had better ADG and FCR than pigs given the 20 °C meal, pigs of the 10 °C meal being intermediate (ADG: 773, 740 and 764 g/d, respectively; P=0.02; FCR: 2.58, 2.69 and 2.61 kg/kg, respectively; P=0.03). Performance was similar among treatments from d 52 to 100 (P>0.10). Overall from d 0 to 100, FCR of pigs distributed the 30 °C feed was 2.2% lower than pigs given the 20 °C or the 10 °C meals (2.69 vs 2.77 and 2.74 kg/kg, respectively; P=0.04). Live weight at d 100 was higher for pigs given 30 °C meal than for pigs fed at 20 °C, pigs with a 10 °C meal being intermediate (110.4, 108.7 and 109.6 kg, respectively; P=0.04). 30 °C pigs tended to have a higher back fat depth than 20 and 10 °C pigs (13.7 vs 12.8 and 13.0 mm, respectively; P=0.07). These results are in agreement with the amount of heat exchange energy required to raise a liquid feed to body temperature. An additional profit of 1.1 € per pig for heated meal vs temp/cold meal was calculated on the basis of the study technical results. Under the economic conditions of 2016, a 2.2% decrease of the FCR could amortize an investment in a renewable energy up to € 5,000 per year in the case of a fattening unit with capacity for 1,500 pigs.