Background

The producer is rewarded economically by receiving a higher dollar value for these pigs. However, producing a consistently lean, heavily muscled pig is difficult.

Objectives

To determine the farm-level factors associated with producing pigs with carcasses with low back fat.

Results

A survey of 90 farms was conducted to determine the relationship between farm-level factors and carcass quality as measured over a 2-year time period. All pigs were weighed prior to marketing by 47% of the producers and a further 32% of the producers weighed some of their pigs. On average, 58% of pigs were weighed before marketing. Most producers used a single source of genetics for their gilts and boars but usually these sources differed. The average back fat recorded was 19.5 mm (SD=4.5) with a median of 19 mm and a farm level coefficient of variation of 21%. Compared to farms using multiple sources of genetics, using one source of gilts and one source of boars reduced the variation in the fat depth.

Farms with PRRS in the grower pigs had a higher fat depth (by 0.54 mm). Increasing hot carcass weight increased fat depth by 0.15 mm. Producers who do not weigh any pigs had leaner pigs (-0.80 mm) but they also had lighter weight pigs. Decreasing the minimum space allowed for grower pigs decreased the fat depth. Pigs raised in nursery units managed all in all out by pen (-4 mm) or room (-1.5 mm) had a lower fat depth than pigs managed in a continuous flow nurseries.

Take Home Message

To reduce fat depth of carcasses, producers would be advised to

• control PRRS in the grower barn
• raise nursery pigs in all in all out units either by pen or room rather than in continuous flow systems

• use a single source of gilt genetics and a single source of boar genetics

Further Information