Breeding and Genetics: Genetics Methodology 2

The objective of this presentation will be to relate field experiences regarding the impact of gilt age and lactation length on sow productivity. Over time the largest percentage of females to farrow within a herd are parity one and therefore overall herd productivity is greatly influenced by the results achieved by them. Gilt age and weight at first service have a direct impact on these results. Field observations show that increasing gilt age and weight by approximately 30 days and 20 kilograms respectively, over traditional targets of 210 days and 125 kilograms can improve first parity born alive by as much as .75 pig per litter. Early weaning programs designed to increase sow productivity and improve health have driven weaning averages below 21 days of age. Many producers have noted that weaning this early has a negative impact on subsequent parity born alive. To explore this, commercial production herds containing Danish genetics were examined. Born alive per litter was treated as a dependent variable and previous lactation length as an independent variable within each herd. The results of this analysis showed an average decrease in subsequent parity born alive of .12 pig per day for each day decrease in weaning average between 21 and 15.