At weaning, pigs have to cope with abrupt withdrawal of sow milk, and this often causes appetite suppression due to marked changes in diet form and composition. Feed flavor and sweetener are believed to increase feed palatability, and subsequently improve feed intake, average daily gain, and immune response of weanling pigs. However, data that confirm this hypothesis are limited. Therefore, it was the objective of this experiment to test the hypothesis that supplementation of feed flavor and feed sweetener in diets fed to weanling pigs improve growth performance.

Experimental design

One hundred twenty-eight newly weaned pigs (initial BW: 5.97 ± 0.55 kg) were allotted to 1 of 4 diets. There were 4 pigs per pen with 8 replicate pens per treatment. A 3-phase feeding program was used with d 1 to 7 as phase 1, d 8 to 21 as phase 2, and d 22 to 42 as phase 3. A control diet was formulated based on corn and soybean meal. Three additional diets were formulated by adding feed flavor, feed sweetener, or the combination of feed flavor and feed sweeter to the control diet (Table 1). Therefore, 4 diets were used. Individual pig weights were recorded at the beginning of the experiment, on d 7, d 14, d 21, d 28, d 35, and on d 42. Feed addition was recorded daily and the weight of feed left in the feeder was recorded on d 7, d 14, d 21, d 28, d 35, and on d 42. Growth performance data were summarized for each week and phase and for the overall duration of the experiment, and fecal scores were assessed visually every other day throughout the experiment.

Results

There was no effect of feed flavor, feed sweetener, or the combination of feed flavor and sweetener on final body weight, ADG, ADFI, and G:F of pigs from d 1 to 7 (Table 1). Greater (P < 0.05) ADG and ADFI were observed in pigs fed the feed sweetener diet compared with pigs fed the control diet in Phase 2. Greater (P < 0.05) ADFI was also observed in pigs fed the feed sweetener diet compared with pigs fed the feed flavor diet or the control diet in Phase 3. The observed improvements in ADG and ADFI resulted in greater (P < 0.05) final body weight in pigs fed the feed sweetener diet compared with pigs fed the control diet on d 14, 21, 35, and 42. For the overall phase, a tendency for an improved (P < 0.10) ADG and improvement (P < 0.05) in ADFI were observed when pigs were fed the diet containing feed sweetener. Inclusion of feed flavor, feed sweetener, or the combination of feed flavor and sweetener in diets did not affect fecal scores of pigs (Table 2). However, a reduction (P = 0.05) in diarrhea frequency was observed for pigs fed the feed flavor diet compared with pigs fed the control diet in phase 2 and in the overall phase.

Key points

• Supplementation of feed sweetener in diets improved ADFI, ADG, and final body weight of weanling pigs.
• Supplementation of feed flavor in diets reduced the incidence of diarrhea for the overall experimental period.

Table 1. Growth performance for pigs fed the experimental diets¹

¹Data are least square means of 8 observations for all treatments.

²FF = feed flavor; FS = feed sweetener (DDC Nutrition LLC, La Mirada, CA).

³ADG = average daily gain; ADFI= average daily feed intake; G:F = gain:feed.

^a-cMeans within a row lacking a common letter are different (P ≤ 0.05).

^x-yMeans within a row lacking a common letter tend to be different (P ≤ 0.10).

Table 2. Fecal score and frequency of diarrhea for pigs fed the experimental diets¹

¹Data are least square means of 8 observations for all treatments.

²FF = feed flavor; FS = feed sweetener (DDC Nutrition LLC, La Mirada, CA).

³Diarrhea score = 1, normal feces; 2, moist feces; 3, mild diarrhea; 4, severe diarrhea; 5, watery diarrhea.

⁴Pen days = number of pens × the number of days assessing diarrhea scores.

⁵Frequency = (number of pen days with diarrhea scores ≥ 3/pen days)*100.