Sweet vs. Salty Former Food Products in Post-Weaning Piglets: Effects on Growth, Apparent Total Tract Digestibility and Blood Metabolites

SIMPLE SUMMARY: Nowadays, researchers need to find a solution to the growing demand for sustainable animal productions. Livestock animal’s nutrition is the component with major impacts on environment and economy. The biggest challenge is to find alternative feed ingredients to minimize and valorize the food leftovers. Food industry leftovers, also called former food products, could be a valid alternative to grains in young pigs’ nutrition. From a nutritional point of view, these ingredients are very similar to standard cereals, like corn. The results from this study suggest that a partial substitution of standard ingredients with two different sources of former food products in the diets of post-weaned pigs is possible, without any negative effects on growth performance and health of animals. ABSTRACT: Former food products (FFPs) have a great potential to replace conventional feed ingredients. This study aimed to investigate the possibility to partially replace standard ingredients with two different types of FFPs: bakery (FFPs-B) or confectionary (FFPs-C) FFPs and their effects on growth performances, feed digestibility and metabolic status in post-weaning piglets. Thirty-six post-weaning piglets were randomly assigned to three experimental diets (n = 12 per diet) for 42 days: a standard diet (CTR), a diet where 30% of standard ingredients were replaced by confectionary FFPs (FFPs-C) and a diet where 30% of standard ingredients were replaced by bakery FFPs (FFPs-B). Individual body weight and fecal dry matter were measured weekly. Feed intake (FI) was determined daily. Average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) were calculated. Fecal samples were collected daily for three days/week to determine apparent total tract digestibility of dry matter (ATTD). At day 0, 21 and 42, blood samples were collected from all the piglets. No significant differences (p > 0.05) between groups were found in growth performances and metabolic profile. However, ATTD in FFPs-B group was lower (p < 0.05) compared to the CTR group at the end of the experiment. This study confirmed the possibility to formulate homogeneous diets integrated with 30% of both categories of FFPs. Further investigations are needed to clarify the effects of bakery former food products on the digestibility of the diet.