Feeding Crude Glycerin to Finishing Iberian Crossbred Pigs: Effects on Growth Performance, Nutrient Digestibility, and Blood Parameters

SIMPLE SUMMARY: Crude glycerin can be used as a substitute for some feed ingredients in white pig diets. However, there are few reports on its use in Iberian crossbred pigs. This study aimed to evaluate the effects of three levels of crude glycerin (0, 50, and 100 g/kg) on performance parameters, nutrient digestibility, and blood parameters of Iberian × Duroc pigs during the last phase of fattening. The results show that the addition of glycerin did not affect average daily gain, average feed intake, or feed conversion ratio. Digestibility of dry matter, organic matter, and crude protein and serum parameter concentrations were statistically similar among the evaluated treatments. It is concluded that crude glycerin up to 100 g/kg could be included in the diets of Iberian pigs for the last fattening phase with no negative effects. ABSTRACT: A total of 192 Iberian × Duroc pigs kept under intensive conditions were used to investigate the effects of feeding crude glycerin on growth performance, nutrient digestibility, and blood parameters. Animals were blocked by initial body weight (96.0 ± 11.3 kg) and allotted to pens (16 pigs per pen). Pens were assigned randomly to one of three dietary treatments (four pens per treatment). Dietary treatments contained 0, 5, or 10% of crude glycerin proportionally substituting for wheat (G0, G5, and G10, respectively). Diets were formulated to be isoenergetic and isoaminoacidic. No significant effect of crude glycerin was observed on average daily gain, average feed intake, or feed conversion ratio. The apparent total tract digestibility of dry matter, organic matter, and crude protein was no different between treatments. Total serum protein, albumin, glucose, insulin, and IGF-1 were not affected by glycerin inclusion. In conclusion, crude glycerin up to 100 g/kg can be included in the diets of finishing Iberian crossbred pigs without any negative effect on growth performance, digestibility, or serum metabolic parameters.