Effect of Birth Weight on Subsequent Pig Performance
There is a direct relationship between piglet birth weight and subsequent performance to market, including carcass quality and meat quality, according to PIC research conducted by N. Matthews, S. Jungst, C. Jones, B. Fields and A. Sosnicki. They presented their paper at the 55th International Congress of Meat Science and Technology.
11 November 2009
3 minute read
Data from 5,186 pigs, representing 464 litters, which were sired by 43 PIC380 boars, were used in the analyses. Each piglet was weighted at birth and its performance was monitored from birth to the time the pigs were harvested.
At the farm where the trial was conducted, aggressive cross-fostering occurred after piglets were weighed. Lifetime average daily carcass gain was calculated for each pig by dividing the weight of the carcass by the age of the pig when it was harvested and was the measure of growth in the trial. Carcass backfat thickness, loin depth and lean percentage were adjusted to 175 days of age at harvest.
Results
- Pre-weaning survivability, nursery survivability and full-value pigs marketed percentages increased as birth weight increased. Most of this improvement occurred in piglets weighing less than 1.36 kg
- Lifetime average daily carcass gain and hot carcass weight increased as birth weight increased
- Ham, belly, loin and boneless loin weights all increased as birth weight increased when adjusted to a constant age at harvest
- When adjusted to 175 days of age, backfat thickness decreased and loin depth increased as birth weight increased, resulting in higher lean percentage
- Objective loin colour measurements of Minolta L* (darker) and b* (less yellow) improved as birth weight increased, but Minolta a* (redness) was not affected by birth weight.
- Subjective loin colour (Japanese colour score), loin pH, loin drip loss and loin firmness were not affected by birth weight
- Loin marbling decreased as birth weight increased
Results from these data clearly show that lower piglet weights have a detrimental effect on the survivability of the piglet from birth to market, lifetime growth rate, carcass composition and, to some extent, meat quality.
As number of piglets born alive increases due to selection for litter sizes, the pig industry must find new management strategies to decrease the incidence of piglets weighing less than 900g at birth.
November 2009
