Characterization of feed intake patterns during lactation in commercial swine herds.

This study created and used a data-base containing 25,719 farrowing and 19,393 subsequent litter records abstracted from the PigCHAMP records of 30 commercial farms and daily feed intake records of 25,040 of these lactating sows. Each lactation feed record was categorized into one of six patterns: RAPID, rapid increase in feed intake following farrowing; MAJOR, major drop in feed intake during lactation; MINOR, minor drop; LLL, low feed intake throughout lactation; LHH, low feed intake during the first week then increasing for the remainder of lactation; and GRADUAL, gradual increase in feed intake throughout lactation. At the herd level, patterns RAPID, MAJOR, MINOR, LLL, LHH, and GRADUAL were observed in 22.8%, 32.9%, 27.8%, 1.0%, 8%, and 14.7% of sows, respectively. On a sow basis, across all feed intake records of all farms, patterns RAPID, MAJOR, MINOR, LLL, LHH, and GRADUAL were observed at frequencies of 17.8%, 38.3%, 25.8%, 1.2%, 1.5%, and 15.4%, respectively. Using logistic regression, the risk factors affecting the occurrence of MAJOR and MINOR patterns were lower parity, thicker backfat, higher room temperature, and greater feed intake during early lactation. Average daily feed intake and the day of peak intake were 5.2 (1.4 SD) kg/sow and 12.6 (4.6 SD) d after farrowing. Regression coefficients of factors affecting ADFI derived from multiple regression analyses were 247 g for parity, 9 g for weaning litter weight (kg), -13 g for room temperature (degree C), 62 g for lactation length (d), and -.4 g for energy density (kcal/kg). This study demonstrated substantial individual sow and farm variation in overall feed intake and pattern of feed intake during lactation. It also identified key risk factors (i.e., parity, lactation length, room temperature, weaning litter weights, energy density) for ADFI and pattern of feed intake on commercial farms.