The effect of thermal processing and physical form of pig’s diet

Abstract

Changes in diet form and thermal processing can be beneficial to pig production. Our objective with this study was to better understand and analyze the effects of diet form (mash vs. pellets) on feed wastage, performance, and the carcass of pigs. Forty pigs, castrated males and females between 21 and 127 days old, were distributed in a randomized block design into two treatments: mash diet and pelleted diet. We analyzed the data through generalized linear mixed models, considering the blocks (initial weight and sex) as random effects and the pens as the experimental unit, totalizing two treatments with 10 replicates of two animals each. We applied the F-test to compare means and considered significant if P<0.05 and marginally significant if 0.05≤P<0.1. During the nursery period (21 to 62 days old), pigs fed with the pelleted diet showed a decrease in (P<0.05) daily feed intake (DFI) and an improvement in feed conversion ratio (FCR). However, the diets showed no difference (P>0.1) in daily weight gain (DWG). From 21 to 42 days old, we found that those fed mash diet had higher feed wastage (P<0.05) compared to those fed with the pelleted diet. In the following phase, FCR (P<0.05) and DWG (P<0.05) were higher in pigs up to 80 days old, and a higher DWG (P<0.1) in those up to 101 days old fed with the thermally processed diet. In pigs from 62 to 127 days old, DFI, DWG, and FCR had no statistical difference (P>0.1) between the groups evaluated. Regarding the carcass, we observed an increase in backfat thickness (P<0.1) in pigs fed with the pelleted diet when compared to others, but there was no change in loin depth (P>0.1). These results suggest that pelleting is a viable thermal processing for pig production, because it reduces the amount of feed wastage, improves performance of male and female pigs in the nursery and growing phases and altered the carcass of these animals.