@article{peppmeier_leonard_knauer_2023, title={Effect of Temperature and Humidity on Daily Feeding Behavior in Swine}, volume={101}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skad068.010}, abstractNote={Abstract
               Heat stress has negative impacts on pork production, particularly during the grow-finish phase. During heat stress events, swine alter feeding behavior to reduce heat production, which can negatively affect performance. Recent technology advancements in feed management systems allow for individualized data recording of feeding behavior for group housed pigs during the finishing phase. The objective of this study was to utilize an RFID-based feed management system to determine feeding behavior patterns of finishing pigs during heat stress conditions and identify changes in behavior due to heat stress events. Data included one pen of 29 Duroc boars reared in a mechanically ventilated facility in north central North Carolina. Feed Intake Recording Equipment (FIRE) pig feeders (n = 3; Osborne Technologies) fed individual pigs in the group housed setting using RFID technology and recorded the number of visits, feed intake of each visit, visit duration, and body weight of each pig during each visit. Feeders were calibrated once per week to ensure accuracy of feed intake and body weight measurements. On day 1 of the study, pigs were placed in the experimental pen and body weights were recorded (37.4 kg ± 4.9 kg) using the FIRE feeders. Air temperature, humidity, and dew point data were collected continuously every 5 minutes from day 13 until the end of the finishing period. Pigs exited finishing (134.5 ± 8.6 kg) on day 83. Feeding behavior traits (number of visits and feed intake) were summarized by day. Temperature, humidity, and heat index were summarized by a maximum, minimum, and mean value for each day. Average temperature, humidity, feeder visits a day, and average daily feed intake across the trial was 26.3 ± 1.6 º C, 75.8 ± 6.7%, 6.1 ± 1.0 visits, 2.66 ± 0.39 kg. Models were used to associate feeding behavior traits with the quadratic effects of day and the linear effects of average temperature and humidity and the interaction of temperature and humidity. Temperature and humidity were associated (P < 0.01) number of feeder visits and average daily intake per day. Further, there was an interaction (P < 0.01) between temperature and humidity in relation to number of feeder visits and average daily feed intake. Results suggest substantial variation in feeding behaviors can be explained by temperature and humidity.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Peppmeier, Zack and Leonard, Suzanne M. and Knauer, Mark}, year={2023}, month={May} }
 @article{peppmeier_howard_knauer_leonard_2023, title={Estimating backfat depth, loin depth, and intramuscular fat percentage from ultrasound images in swine}, volume={17}, ISSN={["1751-732X"]}, url={https://doi.org/10.1016/j.animal.2023.100969}, DOI={10.1016/j.animal.2023.100969}, abstractNote={Fast, accurate, and reliable estimates of backfat depth, loin depth, and intramuscular fat percentage in swine breeding stock are used to increase genetic improvement and farm profitability. The objective of this study was to develop an equation-based model for the estimation of swine backfat depth, loin depth, and intramuscular fat percentage estimates obtained from longitudinal ultrasound images. Images were collected from purebred Duroc (n = 230), purebred Large White (n = 154), and commercial (n = 190) pigs born in January 2021 at three farms located in North Carolina. An Exapad ultrasound machine captured longitudinal images across the 10th to 13th ribs at 182 (±12.8 SD) days of pig age. The total number of images processed for Duroc, Large White, and commercial pigs was 1 385, 928, and 1 168 images, respectively. To establish a standard measurement for model comparison, trained personnel following standard company procedures using the BioSoft Toolbox (v4.0.1.2; Biotronics Inc., Ames, IA) obtained backfat and loin depth measurements from the images. Longissimus muscle intramuscular fat percentage was predicted using near-infrared spectroscopy at approximately 22 h postmortem. Backfat and loin depth estimation were conducted only for commercial pigs (n = 190) while intramuscular fat estimation was conducted on all pigs (n = 574). Average backfat depth, loin depth, and intramuscular fat percentage were 14.6 (±2.6 SD) mm, 63.7 (±5.5 SD) mm, and 2.21 (±0.82 SD) %. Image analysis and estimation model development were conducted in MATLAB R2021a. Edge detection via the image gradient was applied to segment ultrasound images into backfat, loin, and rib regions. Segmented images were used to estimate backfat depth, loin depth, and loin intramuscular fat percentage. After image quality control and filtering, the image inclusion rate for each breed-trait combination ranged from 76 to 97%. All Duroc and commercial pigs and 97% of Large White pigs were represented by at least one image for trait estimation. Coefficient of determination of models for the estimation of backfat depth, loin depth, and intramuscular fat percentage were 0.58, 0.57, and 0.56, respectively. Root mean square error of backfat depth, loin depth, and intramuscular fat estimation were 1.65 mm, 3.58 mm, and 0.54%, respectively. Results demonstrate the feasibility of using ultrasound image gradient and an equation-based approach to estimate swine backfat and loin depth, and intramuscular fat percentage. This equation-based approach to estimate carcass traits in live swine can enhance genetic improvement.}, number={10}, journal={ANIMAL}, author={Peppmeier, Z. C. and Howard, J. T. and Knauer, M. T. and Leonard, S. M.}, year={2023}, month={Oct} }
 @article{knauer_peppmeier_purvis_2023, title={Impact of Prefarrow Fat Supplementation on Piglet Survival and Subsequent Reproduction}, volume={101}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skad341.344}, abstractNote={Abstract
               Past research (40+ years ago) suggests feeding fat to sows before parturition and during lactation improves piglet energy stores, sow colostrum fat percentage, sow milk fat percentage and piglet survival. Therefore, the objective was to evaluate the impact of sow fat feeding on piglet survival and throughput in a modern production system. Data were collected from 1,866 sows at a 3,600 sow commercial farm in eastern North Carolina between May and August. Sows were randomly assigned to one of four treatments from day 108 of gestation until farrowing (no supplementation; Control), supplemented with 227g or 454g of soybean oil per day, or supplemented with 227g of coconut oil per day. Oil sources were top dressed daily with 2.27kg of lactation diet. After farrowing, sows had ad libitum access to the lactation diet. At birth, piglets received a colored ear tag corresponding to prefarrow diet. Traits recorded included total number of piglets born, stillborns, crossfosters, number weaned, piglet survival (number weaned ÷ total number born), litter weaning weight, lactation length, whether a sow farrowed a subsequent litter, subsequent total number born, subsequent number born alive, subsequent stillborns, Knauer sow body condition caliper score prefarrow and sow caliper score at weaning. Linear models were used in statistical analysis. Fixed effects included sow prefarrow diet, parity, contemporary group and location of the sow within the farrowing room. Covariates were included when applicable. Results are shown in Table 1. Stillborns and stillborn percentage did not differ (P > 0.05) between dietary treatments. Yet sows supplemented with soybean oil tended (P = 0.10) to have fewer stillborn piglets (0.06 piglets) than Control sows. No differences (P > 0.05) in piglet survival across dietary treatments were observed. Sows supplemented with soybean or coconut oil prefarrow had greater (P < 0.05) subsequent total number born (13.71 vs. 13.31 piglets) and tended (P = 0.07) to have greater subsequent number born alive (13.07 vs. 12.72 piglets) than Control fed sows. Accordingly, sows supplemented with soybean oil tended (P = 0.08) to have more subsequent total number born (13.69 vs. 13.31 piglets) and tended (P = 0.09) to have greater subsequent number born alive (13.07 vs. 12.72 piglets) than Control fed sows. No differences (P > 0.05) in sow body condition loss during lactation were observed between dietary treatments. In summary, prefarrow fat supplementation did not impact piglet survival but did enhance subsequent litter size. The authors would like to thank the United Soybean Board for funding projects designed to enhance pig farmer profit.
               }, journal={JOURNAL OF ANIMAL SCIENCE}, author={Knauer, Mark and Peppmeier, Zack and Purvis, Jerry}, year={2023}, month={Oct}, pages={302–303} }
 @article{knauer_peppmeier_leonard_2023, title={Sow Location Within Farrowing Room Impacts Reproduction During Heat Stress.}, volume={101}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skad068.013}, abstractNote={Abstract
               The objective was to evaluate the impact of sow location, within farrowing room, on reproduction during periods of heat stress. Data were collected on 1,866 sows at a 3,600-sow commercial farm in eastern North Carolina from May to August 2021. In the farrowing buildings, evaporative cool cell pads cooled the air entering the hallway. Cooled air, from the hallway, then entered the farrowing rooms through inlets at the front of the room and was pulled through the room by fans in the back of the farrowing room. For data analysis, each farrowing room was divided into four zones. Zone 1 included the sows at the front of the farrowing room near the inlets letting in cooled air. Zone 4 included sows at the back of the room where air exited the building through fans embedded within the wall. Zones 2 and 3 were intermediate. Each farrowing room on the farm housed between 18 and 36 sows. After farrowing, sows had ad libitum access to the lactation diet. Traits included piglet survival (number weaned ÷ total number born) the percentage of sows conceiving by 7 days after weaning, subsequent total number born, subsequent number born alive, subsequent stillborns, sow caliper score prefarrow, sow caliper score at weaning and sow caliper lactation loss. Results are shown in Table 1. Piglet survival was greater (P < 0.05) for sows that farrowed at the front of the room near the cool air inlets. Similarly, litter weaning weight was heavier (P < 0.05) near the cool air inlets relative to the back part of the farrowing room. The percentage of sows that conceived by 7 days after weaning, and farrowed, was linearly associated (P < 0.05) with farrowing zone. Sows near the cool air inlets lost less (P < 0.05) body condition and farrowed more (P < 0.05) piglets in the subsequent litter relative to sows in the back of the farrowing room. Results showed sows that farrowed at the front of the farrowing room lost less body condition, had greater piglet survival, heavier litter weaning weights and were more likely to be rebred and conceive by 7 days after weaning relative to sows farrowing in the back of the farrowing room.
               }, journal={JOURNAL OF ANIMAL SCIENCE}, author={Knauer, Mark and Peppmeier, Zack and Leonard, Suzanne M.}, year={2023}, month={May} }
 @article{knauer_peppmeier_2021, title={Effect of Substandard Teats on Piglet and Sow Performance}, volume={99}, ISSN={["1525-3163"]}, DOI={10.1093/jas/skab054.225}, abstractNote={Abstract
               The objective of the study was to evaluate sow teat quality in relation to subsequent reproductive throughput. Data included one cohort of 42 Landrace × Large White second parity maternal line sows at the Tidewater Research Station (Plymouth, NC). Functional teats (FUNCTIONAL) were classified pre-farrow as acceptable (ACCEPTABLE) or substandard (SUBSTANDARD). Teats were categorized as SUBSTANDARD when teat size was ≤75% of ACCEPTABLE. At day 20 of lactation, ACCEPTABLE and SUBSTANDARD were assessed for the presence of a swollen mammary gland and piglets observed nursing SUBSTANDARD were recorded (24 piglets from 15 litters). Means for FUNCTIONAL, ACCEPTABLE and SUBSTANDARD were 15.07, 13.59 and 1.48 teats, respectively. Biological dam traits included birth weight (BWT), total number born (TNB), litter size at weaning (LSW) and piglet survival (LSW/TNB). Weaning weight (WWT) was considered a trait of the nurse dam. Means for TNB, LSW, litter BWT and litter WWT were 13.4, 10.9, 17.8 kg and 57.8 kg, respectively. Data was analyzed using a chi-square test for binary traits and linear mixed models for continuous traits. At weaning, a greater (P < 0.01) proportion of ACCEPTABLE had a functional mammary gland when compared to SUBSTANDARD (76 vs. 47%). Within litters, piglets nursing SUBSTANDARD tended (em>P = 0.09) to be 158 grams lighter at weaning in comparison to ACCEPTABLE. Yet BWT of SUBSTANDARD piglets did not differ (em>P = 0.60) from piglets nursing ACCEPTABLE. Across litters, an increase in one SUBSTANDARD tended (em>P = 0.07) to reduce litter WWT by 1.74 kilograms. An increase in one SUBSTANDARD tended (em>P < 0.07) to increase piglet survival by 3.5%. Results suggest substandard teats, identified pre-farrow, are less likely to have a functional mammary gland at weaning, impair piglet quality yet may enhance piglet survival.}, journal={JOURNAL OF ANIMAL SCIENCE}, author={Knauer, Mark and Peppmeier, Zack}, year={2021}, month={May}, pages={133–133} }