Characterizing sow feed intake during lactation to explain litter and subsequent farrowing performance

Abstract Variation in feed intake results in nearly 20% of sows consuming less than the recommended lysine (Lys) intake for lactating sows. The Lys requirement for lactating sows is based on litter size and piglet average daily gain which influences milk production. Litter size continues to increase every year causing the need for routine reevaluation of nutrient requirements. If dietary inclusion levels are not continuously adjusted this can lead to inadequate daily Lys and energy intake and may negatively impact sow body condition and litter performance. The objective was to characterize average daily feed intake of sows and define feed intake patterns and their effects on sow body weight, farrowing performance, litter performance, and subsequent farrowing performance. Average daily feed intake during lactation was recorded for 4,248 sows from 7 independent research studies. Data collection occurred from November 2021 through November 2023 at a commercial breed to wean facility in western Illinois. Each sow was categorized as: consistently low intake (<5.5 kg/d) throughout the lactation (LLL); low intakes (<5 kg/d) in the first week, then gradually increased throughout the rest of the lactation period (LHH); gradual increase in intake throughout lactation with no drop and a peak intake after d 10 of lactation (Gradual); rapid increase in intake with no drop and the peak intake met before d 10 (Rapid); a major drop in feed intake (> 1.6 kg decrease for ≥ 2 d) any time during lactation (MAJOR); minor drop ( ≤ 1.6 kg for ≥ 2 day) (MINOR). Sows were also separated into low (quartile 1; ≤ 25%), average (quartile 2 through 3), or high feed intake (quartile 4; ≥75%) by parity (P1, P2, P3+). Sows in the LLL category were younger in parity, had the greatest pre-weaned mortality, weaned the lightest average pigs, and experienced the greatest loss in body weight percentage compared with sows in all other feed intake categories. Further, sows in the LLL and LHH categories had 1 fewer subsequent pig born compared with sows in the other 4 categories. These data support historical findings that feed intake patterns directly contribute to current litter farrowing performance. Lactation intake patterns also influence subsequent farrowing performance. Identifying under-consuming sows which are likely Lys and energy deficient to allow producers opportunities to promote consistent, adequate daily intakes to these groups and mitigate negative impacts on sow and litter performance.