By Rafe Royall, Mike Tokach, Jason Woodworth, Joel DeRouchey, Jordan Gebhardt, Robert Goodband and Katelyn Gaffield, Kansas State University

During lactation, maximizing sow feed intake is critical to prevent body reserve mobilization and sustain milk production for litter growth. However, sow farms located in hot and humid climates have difficulties maintaining high levels of lactation feed intake, especially during the summer months, which may lead to poorer performance.

Several factors may affect sow feed intake; one is feeder type and design. While there are numerous types of lactation feeders on the market, a good feeder design can help improve sow feed intake and reduce feed wastage. In finishing pigs, wet/dry feeders have been shown to increase average daily feed intake and average daily gain, but there is limited research on the effects of wet/dry feeder implementation in lactation.  Therefore, the objective of this experiment was to evaluate the effect of different lactation feeder designs on sow farrowing performance, litter growth performance and feeder cleaning criteria.

Animals and treatments

There were 72 stalls per room. A total of four farrowing rooms (288 stalls; 96 stalls per lactation feeder treatment) were used for each group. The trial was conducted in two sequential farrowing groups for a total of 576 sows enrolled on test.

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The first group of sows (PIC 1050) farrowed between June 7 and June 17, 2023, and piglets were weaned between June 29 and July 4, 2023. The second group of sows farrowed between July 4 and July 13, 2023, and piglets were weaned between July 27 and August 1, 2023. On day 112 to 114 of gestation, sows were moved to the farrowing house, and randomly allotted to one of three feeder types based on parity and caliper score. Each of the three feeder types were equipped with the SowMax ad-lib sow feed hopper (SKU: 7150890500; Hog Slat). Feeder types consisted of: 1) dry lactation feeder with a separate nipple drinker available outside of the feeder (Hog Slat, Newton Grove, North Carolina); 2) wet/dry lactation feeder with a divider to separate feed and water (Hog Slat), or 3) the wet/dry lactation feeder without a divider (Hog Slat; Figure 1). The wet/dry feeders had a nipple drinker near the bottom of the feeder to allow sows free access to water.

The same commercial lactation feed was fed to all sows (Table 1). Pre-farrowing, sows were provided approximately 2 pounds in the morning and the afternoon, for a total of 4 lbs. per day, of the lactation diet. After farrowing, sows were provided ad libitum access to the lactation feed with individual hoppers, and each feed addition was weighed and electronically recorded. Feed addition to each feeder was registered to the stall (location pen) with the date and weight recorded for calculating feed disappearance. Prior to each feed addition, all feeders were checked for old/moldy feed and this feed was removed. Viable piglets were individually tagged with an RFID tag within 24 hours of birth. The average weaning age was 20.9 d.

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Data and sample collection

Feed, sow and litter data were recorded and stored using the LeeO system (Prairie Systems, Spencer, Iowa). A walk-on platform scale was used to weigh sows before entering the farrowing house and at weaning. Sow caliper score was taken between days 109 and 111 of gestation. Caliper scores 6-12, 12-17 and 17-22 correspond to body condition scores of 1, 2 and 3, respectively.

For litter performance, piglets were registered under the sow and crate, and weighed individually at birth and at weaning. Non-viable piglets (low birth weight or dead before tagging), stillborn and mummies were recorded but not weighed. Any cross-fostering and mortalities throughout the lactation period were recorded.

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After weaning, three farm employees were designated to wash feeders, and cleaning times for several feeders per feeder type were recorded. The number of feeders used was 59, 57 and 57 for the dry feeder, wet/dry feeder with a divider, and wet/dry feeder without a divider, respectively. For economic data, the lactation feed cost was $330/ton, litter value was $0.70/lb of litter weight, and the labor cost for washing was $23/hr.

Results

There was no evidence of difference in sow weight or caliper score at entry or weaning, or BW change during lactation (Table 2). There was no evidence of difference in total litter or piglet birth BW, total pigs born, or percentage of pigs born alive. However, sows fed with the dry lactation feeder had decreased (P < 0.001) total daily feed disappearance, and average daily feed disappearance compared to those fed with either wet/dry feeder. There was no evidence of difference for litter or pig weaning weight, or litter average daily gain. As a result, litter feed efficiency was improved (P = 0.027) in sows fed with the dry feeder compared to those fed with either wet/dry feeder type.

For economics, sows fed with the dry feeder had reduced (P ≤ 0.006) total lactation feed cost and feed cost per piglet weaned compared to sows fed with either wet/dry feeder. For feeder cleaning criteria, dry feeders had increased (P = 0.001) washing time and washing cost compared to either wet/dry feeder.

In summary, the lack of differences in litter growth performance and sow weight change suggests that sows had similar true lactation feed intake, regardless of feeder design. However, the increased feed disappearance observed when sows were fed with either wet/dry feeder design in this study appears to be due to increased feed wastage. This difference could be explained by additional daily removal of wet feed from either of the wet/dry feeder designs.

Although we did not record the amount of wasted feed, wet/dry feeders had a greater frequency of old/wet feed removal through daily observation, compared to the dry feeder. Therefore, sows fed using the wet/dry feeders (with or without the divider) in this study had greater total feed disappearance, which was likely due to increased feed waste compared to sows fed using the dry feeder. As a result, sows fed using the dry feeder had reduced lactation feed cost and reduced feed cost per pig weaned.

This and other swine nutrition and management research will be discussed at the 2024 K-State Swine Industry Day on Nov. 21.