A total of 200 finishing pigs (average initial BW of 132.3 lb) were used in a 58-d growth
assay to determine the effects of an abrupt change from mash to pellets and pellets to
mash on growth performance and carcass measurements. The experiment was designed
as a randomized complete block with 5 pigs per pen and 10 pens per treatment. There
were 4 treatments with 2 phases of diets utilized. Treatments were mash to mash, mash
to pellets, pellets to mash, and pellets to pellets for Phases 1 and 2 of the experiment.
For Phase 1 (d 0 to 36), pigs fed the pelleted diet had 4% greater (P < 0.06) ADG and
F/G was improved (P < 0.03) by 8% compared to pigs fed mash. For Phase 2 (d 36 to
58) and overall (d 0 to 58), pigs fed the mash diet had poorer (P < 0.01) F/G than pigs
fed the pelleted treatments. Indeed, pigs fed pellets the entire experiment had ADG and
F/G 5 and 8% better (P < 0.01), respectively, than pigs fed mash the entire experiment.
Pigs fed mash during Phase 1 then pellets during Phase 2 had improved (P < 0.01)
ADG and F/G for Phase 2 compared with pigs fed pellets then mash. Overall pigs fed
pellets for either Phase 1 or 2, but not both, tended to have poorer (P < 0.10) ADG and
F/G compared with pigs fed pellets for the entire experiment. With HCW used as a
covariate, no differences (P > 0.15) were observed in dressing percentage, fat thickness,
loin depth, or percentage fat-free lean index (FFLI). Pigs fed pellets tended to have the
greatest growth performance, pigs fed mash the worst, with pigs fed pellets for only part
of the grow-finish phase rating intermediate.
