Bottom Line for Better Production Systems

If prenatal development affects postnatal variation in growth performance, what are the practical resolutions to this problem?

The continued selection for increased litter size born, without understanding implications for variation in average litter birth weight in litters born to higher-parity sows, seems questionable. Feed costs to finish market hogs continue to rise, and the livestock industry will increasingly compete with other industries seeking to divert these feedstocks to other industrial processes — most notably ethanol production.

The efficiency of feed utilization, and minimal environmental impacts of food-animal production, will become increasingly important issues in our ability to sustain pork production. The net efficiency with which we can produce a pound of high-quality pork is critical to the competitiveness of our industry.

As intensive pork production systems continue to evolve, greater attention is being paid to the concept of segregated management systems. The reasons for adopting segregated production flows vary, but the underlying principle remains the same ? the net advantages that come from managing particular subpopulations of the pork production chain to achieve greater efficiency and consistency of production.

Segregation may be a spatial concept, in a geographic sense, to improve the control of disease transmission at different levels of the production pyramid. Increasingly, segregation involves separation of subpopulations on the basis of their susceptibility to disease challenges compared to, say, more mature animals, or because segregation allows specialized management to be applied in a cost-effective way to these segregated populations.

Segregation in this instance can be on-site within a farm, or even within-barn, depending on the situation and goals.

In light of the above discussion, we suggest that segregation of entire litters on the basis of average litter birth weight may do more to address variation in postnatal growth performance than existing programs of extensive crossfostering, irrespective of average litter birth weight, and the successive sorting of pigs by weight in the later stages of production. Neither of these strategies accepts the major inherent differences in postnatal growth potential that clearly exists between litters with high and low average birth weight.