Economic values for farrowing rate to improve seasonal fertility

Seasonal fertility is the variation in reproductive performance of sows across different seasons. A consistent fertility of sows across seasons is desirable. Seasonal fertility is reflected in farrowing rate because a reduction in farrowing rate is often observed during the summer-autumn period. An independent economic model was developed to derive economic values for farrowing rate. Economic values varied from $2.19 to $1.95 per 1% change in farrowing rate for mean farrowing rates of 72 to 85%. The economic value for farrowing rate predominately accounted for the costs of non-productive days of non-pregnant sows. The model and economic values presented in this study for farrowing rate can be used to extend existing maternal breeding objectives in pigs. Further, the variation in economic values for farrowing rates can be used to consider genotype by season interactions for farrowing rate in pig breeding programs.