References

An Evaluation of Growth Performance in Swine Raised in Commercial and Unrestricted Environments

Purdue University 1998 Swine Research Report. Environmental factors including disease exposure, social stress and less than optimal stocking density limit growth. As a result, pigs managed under commercial conditions are unlikely to express their maximum potential protein accretion, even when allowed ad-libitum access to a high quality, nutrient dense diet. The operational protein accretion is the maximum protein accretion rate that pigs can achieve under specified commercial conditions. This definition implies that for a given genotype, the maximum achievable lean growth rate is limited by the environmental conditions under which the pig is raised. Lean growth curves can be used to estimate the magnitude at which environmental conditions (health status, facilities, stressors) limit the expression of the pigs genetic potential for lean growth. A substantial difference between on-farm and maximum achievable protein accretion or lean growth rates is indicative of major environmental limitations. In such cases, the commercial producer must evaluate the benefits and costs of environmental-management changes.