Are Growth Performance and Fecal Score in Weaning Pigs Affected by the Inclusion Level of Potato Protein Concentrate and the Enclosed Glycoalkaloids in Iso-Nitrogenous Diets?

SIMPLE SUMMARY: Potato protein concentrate (PPC) has been included in piglet diets for many decades because of its properties with respect to piglets’ protein requirements. The inclusion level was limited because of the content of toxic anti-nutritional factors, such as glycoalkaloids (GA). Glycoalkaloid content in PPC is reduced via resource-requiring processing, but if piglets tolerate GA in levels like in the standard PPC, energy-consuming processing can be reduced. The concern when increasing standard PPC levels is the potential negative effects of GA on growth performance. In the experiment, it was shown that piglets’ growth performance was not affected negatively, nor was the fecal score, when fed increasing levels of PPC and hence increasing GA. All diets were formulated to meet the national nutritional requirements for weaner pigs. Interestingly, one of the dietary treatments with high inclusion of standard PPC (and thus GA) displayed greater performance as compared with the group fed a diet without standard PPC. Therefore, it was concluded that standard PPC can be included with high inclusion rates in weaner diets without negatively affecting growth performance or fecal score and that the focus must be on the GA content of the diets rather than the inclusion rate of the standard PPC. ABSTRACT: Glycoalkaloids (GA) are anti-nutritional factors in standard potato protein concentrate (PPC) fed to piglets. Increasing levels of standard PPC was expected to affect growth performance and fecal score negatively. Seven-hundred-and-twenty pigs (7–30 kg) were fed one of the following four diets within three feeding phases (days 0–13, 13–24, and 24–45): control (CTRL), PPC standard inclusion (PPC-S; 4%, 2%, and 0%), high PPC inclusion (PPC-H; 8%, 3.5%, and 2%), and extremely high PPC inclusion (PPC-EH; 12%, 5%, and 3.5%). During days 0–13, CTRL displayed no difference in growth performance compared with the three experimental groups (PPC-S, PPC-H, and PPC-EH). During days 13–24, PPC-H achieved greater (p < 0.001) average daily feed intake (ADFI) compared to CTRL. During days 24–45, no differences between groups were observed. For the overall experimental period (0–45 days), PPC-H displayed greater average daily gain (ADG) (p = 0.010) and ADFI (p = 0.024) compared to CTRL. The feed conversion ratio (FCR) remained unaffected between the groups for all experimental periods. Increasing levels of PPC and hence GA did not affect the probability of diarrhea. In conclusion, increased standard PPC and hence increased levels of GA in isonitrogenous diets did not negatively affect growth performance nor fecal score in piglets (7–30 kg).