Effect of precision feeding strategy on feeding behavior of growing-finishing pigs

Abstract Text: The impact of switching from conventional (three-phase/group) to precision feeding programs (daily-phase/individuals) on feeding behavior of 35 females and 35 barrows (30.4 ± 2.2kg) was evaluated in an 84 d trial. Pigs were housed in the same pen but fed individually according to one of 5 feeding programs (treatments). Five automatic feeders registered individual feeding information (feeder entry and exit times, and the consumed feed per visit) totaling 59,701 feeder visits. Daily standardized ileal digestible (SID) lysine requirements were estimated with a mathematical model using individual daily feed intake and weekly body weight data. Pigs assigned to the three-phase feeding program (3P) received within each 28-d feeding phase the same fixed blend of feeds A (high lysine density) and B (low lysine density) whose lysine concentration corresponded to the requirement of the 80th centile pig of the population at the beginning of the phase. Pigs assigned to one of 4 precision feeding programs received feeds A and B blends adjusted daily to match 110, 100, 90, or 80% of the estimated lysine requirements of each individual pig. Lean and fat body composition were assessed every 28 days by dual-energy X-ray absorptiometry (DXA). Nitrogen excretion was estimated as the difference between intake and retention values. The pig was the experimental unit in variance analysis (MIXED procedure, SAS). Average daily SID lysine intake and nitrogen excretion of 3P pigs were 22.4 and 31.7 g, respectively. Average daily feed intake and weight gain were 2.44 kg and 1.05 kg in 3P pigs. Feeding pigs individually providing 90, 100, and 110% of the daily lysine requirements resulted in the same (P>0.05) feed intake, feed efficiency, and growth performance than the 3P program. Compared to 3P pigs, those fed to daily requirements ate 26% less SID lysine (P<0.05) and excreted 30% less nitrogen (P<0.05). The number of visits, duration, interval between visits, consumption per meal, and intake rate were not affected (P>0.05) by treatments. Feeding behavior responses were not correlated with diet composition (P>0.05). However, feed intake rate was negatively correlated with feed (r=-0.74; P<0.05) and protein efficiencies (r=-0.55; P<0.05). Feeding growing pigs individually with daily tailored diets is an effective approach to reduce lysine supply and nutrient excretion without affecting pig performance or feeding behavior.

Keywords: nutrition, nutrient requirements, precision farming