Animal Industry Report

Extension Number

ASL R2832



Summary and Implications

The objective of this study was to quantify negative deviations from predicted lactation feed intake (LFI) values and the effect of negative deviations on reproductive performance. Daily lactation feed intake values (LFI) were recorded on 10,716 litters farrowed by purebred Yorkshire, Landrace and F1 (Yorkshire x Landrace) sows with an average lactation length of 18.5 days. Daily LFI values were predicted for each litter using the PROC HPMIXED procedure in SAS. An internally studentized residual ≤ -1.71 was characterized as a negative deviation from predicted LFI value (DEV). Total DEV during lactation ranged from 0 occurrences up to 14 negative deviations. However, the occurrence of more than 5 deviations during lactation was rare, and reproductive performance was not statistically affected by additional negative deviations. Twenty-one day litter weaning weight decreased with each additional negative deviation until at least 3 negative deviations occurred in which litter weaning weight remained at a constant value for litters produced by purebred and F1 sows. Wean-to-service interval remained constant when 0, 1, or 2 negative deviations occurred but when the number of negative deviations during lactation reached at least 3, wean-to-service interval began to increase. Limiting the number of DEV during lactation increases the likelihood that a sow will reach her reproductive potential.

Copyright Holder

Iowa State University