Associations between sow lactation length, the productivity of individual sows at their subsequent farrowings, and annual breeding productivity were analyzed using a data base including 14925 farrowing records from 39 swine herds. Longer lactation lengths were associated with higher subsequent litter sizes (both total-born and born-alive), shorter weaning-to-service intervals, longer farrowingto-service intervals, and longer farrowing-to-farrowing intervals (P< 0.0001). The total number of pigs born per sow per year and the number of live born pigs per sow per year were not significantly associated with lactation length (P> 0.2). The observation that reducing lactation length from 30 to 17 days does not significantly affect pigs per sow per year is attributed to the compensatory effects of shorter lactation on pigs born per litter and litters per sow per year. This range of lactation length is commonly employed by American swine producers and appears to incorporate the optimal range for breeding herd productivity as measured in terms of pigs weaned/sow/year. Nevertheless, the optimal lactation length for an individual herd likely will be influenced by its particular management, environmental and financial characteristics.
- Lactation length
- Sow productivity