Y Koketsu1. 1. Department of Clinical and Population Sciences, University of Minnesota, St Paul 55108, USA.
Abstract
OBJECTIVE: To determine productivity characteristics of high-performing swine breeding herds in the United States and to determine associations among number of litters per mated female per year (LMFY), number of pigs weaned per sow (PWS), and lactation duration. DESIGN: Cohort study. SAMPLE POPULATION: 1997 productivity records for 685 herds. PROCEDURE: Herds were ranked on the basis of number of pigs weaned per mated female per year, and herds in the upper 10th percentile of this ranking were designated as high-performing herds. Productivity measurements for these herds were compared with values for the remaining herds. RESULTS: High-performing herds had shorter lactation durations and higher mean breeding female inventories than did the remaining herds. High-performing herds also had better reproductive efficiency and used farrowing facilities more efficiently than did the remaining herds. For the high-performing herds, lactation duration was significantly associated with PWS but was not significantly associated with LMFY. In contrast, for the remaining herds, lactation duration was not significantly associated with PWS but was significantly associated with LMFY. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that high-performing commercial swine farms could increase PWS by improving preweaning mortality rate and number of pigs born alive, but that LMFY was already maximal. For other herds, however, shortening lactation duration would likely decrease farrowing interval and improve efficiency of the reproductive cycle without reducing litter size.
OBJECTIVE: To determine productivity characteristics of high-performing swine breeding herds in the United States and to determine associations among number of litters per mated female per year (LMFY), number of pigs weaned per sow (PWS), and lactation duration. DESIGN: Cohort study. SAMPLE POPULATION: 1997 productivity records for 685 herds. PROCEDURE: Herds were ranked on the basis of number of pigs weaned per mated female per year, and herds in the upper 10th percentile of this ranking were designated as high-performing herds. Productivity measurements for these herds were compared with values for the remaining herds. RESULTS: High-performing herds had shorter lactation durations and higher mean breeding female inventories than did the remaining herds. High-performing herds also had better reproductive efficiency and used farrowing facilities more efficiently than did the remaining herds. For the high-performing herds, lactation duration was significantly associated with PWS but was not significantly associated with LMFY. In contrast, for the remaining herds, lactation duration was not significantly associated with PWS but was significantly associated with LMFY. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that high-performing commercial swine farms could increase PWS by improving preweaning mortality rate and number of pigs born alive, but that LMFY was already maximal. For other herds, however, shortening lactation duration would likely decrease farrowing interval and improve efficiency of the reproductive cycle without reducing litter size.