Effects of different processing techniques of broken rice on processing quality of pellet feed, nutrient digestibility and gut microbiota of weaned piglets.

The present study was conducted to assess the effect of different processing techniques of broken rice on processing quality of pellet feed, growth performance, nutrient digestibility, blood biochemical parameters and fecal microbiota of weaned piglets. A total of 400 crossbred piglets (Duroc × Landrace × Yorkshire) with a mean initial body weight (BW) of 7.24±0.52 kg were used in a 28-day experiment. Piglets were randomly distributed to one of 4 treatment and 10 replicate pens per treatment, with 10 piglets per pen. The dietary treatments were as follows: CON, corn as the main cereal type in the dietary; BR, 70% of the corn replaced by broken rice; ETBR, 70% of the corn replaced by extruded broken rice; EPBR, 70% of the corn replaced by expanded broken rice. Extruded broken rice and expanded broken rice supplementation significantly (P<0.05) increased hardness, pellet durability index (PDI), crispness and starch gelatinization degree. Extruded broken rice and expanded broken rice generated a higher (P<0.05) average daily feed intake (ADFI), increased (P<0.05) average daily gain (ADG), decreased (P<0.05) feed conversion ratio (FCR), and lowered (P<0.05) the diarrhea rate. Piglets fed extruded broken rice displayed high apparent total tract digestibility (ATTD) levels of dry matter (P<0.05), gross energy (P<0.05), crude protein (P<0.05) and organic matter (P<0.05). In addition, extruded broken rice and expanded broken rice supplementation had increased Lactobacillus and Bifidobacterium levels in gut, whereas a lower abundance of the potential pathogens Clostridium_sensu_strictio_1 and Streptococcus was observed. Dietary supplementation of extruded broken rice and expanded broken rice failed to show significant effects on blood biochemical parameters. Combined, 70% corn substituted with broken rice failed to show significant effects. Collectively, extruded broken rice and expanded broken rice supplementation had positively enhanced the pellet quality, growth performance, nutrient digestibility, and gut microbiota of weaned piglets.