Influence of Pellet and Mash Combinations on Pig Growth and Carcass Quality

S.Jaikaran and F.X. Aherne

Alberta Pork Research Center, Alberta Agriculture, Food and Rural Development, 9^th Floor, OS Longman Building, 6909 - 116 Street, Edmonton, AB, Canada, T6H 4P2

The effect of feeding pelleted, mash and pellet-mash combinations of diets at three periods of growth on average daily gain (ADG), average daily feed intake (ADFI), feed efficiency (F/G) and carcass quality were examined in pigs from 20 kg to 110 kg. Pigs were fed either pelleted diets through to 110 kg (PPP), pelleted diet to 80kg then a mash diet (PPM), or pelleted diet to 50 kg then a mash diet (PMM), or a mash diet from 20 kg to 110 kg. Feed and water were supplied ad lib.

Over the entire feeding period, the PPP treatment pigs had the highest (P<.05) ADG and took 7 days less to reach market weight. F/G was lowest for PPP pigs but not significantly different from PPM pigs. However, there was a steady increase in F/G as the duration of mash feeding increased. Consequently, average total feed intake per pig was lowest (P<.05) in the PPP treatment (218kg) followed by PPM , PMM and MMM at 228, 245 and 254 kg, respectively. The improvement in feed usage by PPP pigs over PPM, PMM and MMM pigs was 14.2%, 10.2% and 2.5%, respectively. Therefore, the benefit of feeding pellets increases as the length of time they are fed in the feeding program and it is not likely that the full benefit is achieved by feeding pellets for only a part of the feeding period.

Differences in carcass characteristics such as dressing %, yield %, lean % and carcass index were small and variable among treatments. The most notable effect of treatment on carcass quality was that the PPP treatment produced lower index values than other treatments. This was mainly due to the lower lean content of barrows and higher carcass fat measurements for all pigs on this treatment. When the data was analysed for the effect of sex by diet, barrows tended to have lower carcass yield, lean % and carcass index. A trend was observed for lower backfat thickness (P<0.06) for barrows shifted from pellet to mash in the PPM and PMM treatments when compared to barrows on PPP treatment.

Implication: The data indicate that pelleted feed allows superior ADG in market hogs but carcass indices may suffer. Pelleted diets decreased feed usage by 14% and days to market by 7, compared to mash fed diets. The results provide a basis to determine when pelleting becomes economical.