M. Knauer

Factors associated with sow stayability in 6 genotypes.

The purpose of this study was to determine the association of production factors with stayability to parity 4 (STAY4) under controlled experimental conditions. Data were from 2,293 female pigs, sampled from 6 genetic lines that were entered into the National Pork Producers Council Maternal Line National Genetic Evaluation Program. Genetic lines evaluated included Newsham (NH), National Swine Registry (NSR), American Diamond Swine Genetics (ADSG), Danbred (DAN), and 2 Dekalb-Monsanto lines (DK44 and GPK347). Stepwise logistic regression was utilized in the analysis of STAY4. All effects were nested within genetic line. Categorical effects in the model were arrival date to the wean-to-finish unit (entry date) and breed-gestation-farrowing facility (farm). Continuous effects in the model were gilt backfat, LM depth, ADG, age at puberty, age at first farrowing, and traits recorded before the last litter of the sow (prefarrow backfat, number born alive, number weaned, litter weaning weight, lactation feed intake, lactation backfat loss, and lactation length). Factors significant for STAY4 included farm, entry date, age at first farrowing, ADG, gilt backfat, and lactation before removal effects, as well as feed intake, number born alive, and lactation length. Age at first farrowing and lactation feed intake affected all genetic lines. Regression coefficients for STAY4 on age at first farrowing were -0.014, -0.022, -0.017, -0.016, -0.011, and -0.021 (all P < 0.05), respectively, for NH, NSR, ADSG, DK44, GPK347, and DAN genetic lines. Regression coefficients for STAY4 on lactation feed intake were 0.043, 0.049, 0.051, 0.061, 0.120, and 0.097 (all P < 0.05), respectively, for NH, NSR, ADSG, DK44, GPK347, and DAN females. Age at puberty, age at first farrowing, and lactation feed intake had the greatest effect on STAY4.

Characterization of Lesions in U.S. Cull Sows

Physical and reproductive conditions of 3,158 cull sows from 2 U.S. Midwestern harvest facilities were assessed. Body condition, feet, shoulders, teeth, lungs, and reproductive tracts were visually evaluated for gross lesions at harvest. Based on the observations of this study, body condition score (BCS) was associated with several abnormal conditions of sows. Foot-related lesions (overgrown toes, foot pad lesions) represented the most frequently documented lesions. Temporal associations of the interactions between lesions and BCS are unknown. Even though causal relations were not established by this study, the strong associations observed suggest that sows who do not respond to increased feeding with improved BCS could reasonably be expected to have additional lesions that may impact performance and welfare. On-farm management practices may be related to 1 or more lesions (including foot lesions) that had a high prevalence in this study. Farm management practices and nonhuman animal welfare could not be evaluated with this study so no extrapolation can be given to the type of animal housing or the antemortem behavior of these sows.