bluuebunny/crossref_metadata_2025 huggingface dataset:
75 Assessment of allometric changes of visceral organs in pigs from birth to 10 kg bodyweight at 14 days post-weaning
Authors: Elefson Sarah K , Matthews James C , Monegue H J , Lindemann Merlin D
Published: July 2019

Visceral organs (VO) play a crucial role in nutrient metabolism needed for growth and development. Although many studies have documented selected VO growth during early development or around the time of weaning, few studies have documented complete VO growth from birth through the post-weaning (PW) period. The objective of this study was to assess allometric changes of VO growth from birth through d 14 PW. Crossbred pigs were randomly assigned to slaughter (n = 6, 3 male and 3 female) for tissue collection at birth (pre-suckle), 1 and 7 days after birth, at weaning (20.0 ± 1.3 d), and days 1, 2, 5, 7, and 14 PW. Pigs were fed a common PW diet formulated to meet or exceed NRC (2012) estimates. Body weight (BW) and VO were collected and measured (Table 1). Data were analyzed by ANOVA using GLM procedure of SAS with linear and quadratic effects of age determined by contrast statements. BW, absolute small intestine length (SIL), and absolute large intestine length (LIL) increased (linear, P < 0.001) with age. Absolute stomach, liver, pancreas, and total VO weight (including the previously mentioned organs in addition to heart, lungs, kidneys, and spleen) increased (linear and quadratic, P < 0.0001) with pig age and BW. Relative weight (relative to BW) for stomach (0.52 - 0.82%, respectively), liver (2.99 - 3.17%, respectively), pancreas (0.14 - 0.22 %, respectively), and total VO weight (9.95 - 17.64%, respectively) also increased (linear and quadratic, P < 0.0008) over time (d 0 - 14 PW). The SIL relative to total intestinal length (83.79 - 82.14%, respectively) and relative LIL (16.21 - 17.86, respectively) did not change (P > 0.05) from birth to d 14 PW. In conclusion, the weight of the assessed VO increased hyperallometrically from birth to d 14 PW.
79 Seeing the whole picture: Utilizing GPS technology to determine distance and time calves devote to walking post-weaning
Authors: Nickles Kirsten , Relling Alejandro E , Parker Anthony
Published: July 2019

Common weaning practices in today’s beef industry involve discontinuation of the cow-calf social and nutritional bond. When this bond is discontinued, atypical behaviors of walking and vocalizing are immediately observed in the calf that negatively affect calf welfare. Global positioning systems (GPS) provide an opportunity to quantify the effects of animal activity on welfare. Utilizing GPS technology, we are able to determine total distance walked, speed, total time walking, or total time not walking and the interactions with calf production. Thus, the objective of the present study was to evaluate the effects of a familiar trainer animal on calf production during weaning and more specifically, common weaning behaviors such as walking utilizing a Garmin® product. A total of 80 Angus x Simmental heifer calves were used in this study. In all four replications, heifer calves were allotted to each treatment group (n = 10), trainer animal or control (TR, CON) on the day of weaning. Calves in the TR group were placed on pasture at weaning with the familiar trainer animal, and control calves were placed in a similar size pasture without a trainer animal. Each calf was also fitted with their own GPS collar that recorded on days 0, 7, and 14 relative to initiation of the study for a full 24 hours before removal. Data were analyzed as a randomized complete block design with repeated measurements (SAS 9.4). Placing calves with a familiar trainer animal decreased the distance calves walked (P = 0.001) as well as the amount of time calves were walking (P = 0.001). Placing a familiar trainer animal with calves at weaning, therefore, has an effect on walking distance and amount of time calves devote to walking.
71 Impact of myoglobin oxygenation state at freezing on color stability of frozen and thawed beef
Authors: Henriott Morgan , Ribeiro Felipe , Hart Kellen , Herrera Nicolas , Bland Nicolas , Calkins Chris
Published: July 2019

Myoglobin, when oxygenated, is bright red. The deoxygenated form (purple color) is unstable and can be oxidized to metmyoglobin (brown color). This research was conducted to determine if meat frozen in the oxygenated state could retain bright red color during frozen storage, and after thawing, during retail display. Steaks from 18 USDA Choice strip loins were randomly assigned to a myoglobin state [deoxymyoglobin (DeOxy; immediately packaged), low oxygenation (LoOxy; oxygenated for 30 minutes), and high oxygenation (HiOxy; packaged for 24 h in 80% O2)], frozen storage packaging method (vacuum packaged in oxygen permeable or impermeable film), and retail display after two months of frozen storage [0 d (frozen) and 1–7 d (thawed)]. Following storage, frozen steaks were analyzed for objective color (L*, a*, b*), subjective discoloration, and percent oxymyoglobin (via spectrometer). After thawing, steaks were evaluated throughout 7 d of retail display in oxygen-permeable film. For frozen steaks, there were no differences in discoloration (P>.05). The HiOxy steaks retained the highest percentage oxymyoglobin and highest (reddest) a* values after storage, regardless of packaging film. The lowest percent oxymyoglobin (PPPPP < .05). These data suggest that steaks frozen for two months in the high oxygenation state retain superior color appearance while frozen and during the first part of retail display. It is unknown if this advantage would be retained during longer frozen storage.
72 Use of aspirin to intentionally induce gastrointestinal tract barrier dysfunction in feedlot cattle
Authors: Briggs Nathan G , Brennan Kristen M , Nicholls Griffin , Schoonmaker Jon P
Published: July 2019

Stress negatively effects gastrointestinal tract (GIT) barrier function, resulting in compromised animal health. The objective of this study was to evaluate the effectiveness of aspirin to intentionally induce GIT barrier dysfunction in beef cattle. In experiment 1, sixteen crossbred heifers (425 ± 8.6 kg) were enrolled in 2 experimental periods and allotted by BW to 0, 50, 100, or 200 mg/kg BW aspirin. Four heifers per treatment received the same aspirin dose during each period, which were separated by 4 wks. Heifers were fed a 49.4% corn silage, 50.6% concentrate diet. Aspirin was delivered to animals as an oral bolus. The 200 aspirin treatment was dosed as 100 mg/kg BW aspirin 36 and 24 h prior to Cr-EDTA dosing (1 L; 180 mM). The 50 and 100 aspirin treatments were dosed 24 h prior to Cr-EDTA dosing. Urine was collected every 3 h for 48 h and analyzed for Cr using atomic absorption spectrometry. Serum was collected at 0, 24, and 48 h and analyzed for lipopolysaccharide binding protein (LBP) and interleukin-6 (IL-6) using ELISA. In experiment 2, sixteen crossbred steers (576 ± 14.2 kg) fed the same diet were allotted by BW to the 0 and 200 mg/kg BW aspirin treatments (8 steers/treatment) and were slaughtered 24 h after the last dose. Jejunal tissues were collected and tight junction mRNA expression was determined. Data were analyzed using the MIXED procedure of SAS. Aspirin linearly increased Cr absorption (P = 0.02) and elimination (P = 0.04) rate and linearly decreased mean retention time of Cr (P = 0.02). Aspirin tended to increase jejunal claudin-1 mRNA expression (P = 0.10) but did not affect serum IL-6 or LBP or expression of other jejunal tight junction mRNA (P ≥ 0.20). This study indicates that aspirin disrupts GIT barrier function in beef cattle and has potential as a model in GIT permeability research.
77 Responses to alfalfa supplementation in mice
Authors: Fries-Craft Krysten , Anast Justin , Schmitz-Esser Stephan , Bobeck Elizabeth A
Published: July 2019

Anecdotal evidence suggests health benefits from feeding late cutting alfalfa to non-ruminants, but there is a lack of published literature to support these claims. The objective was to compare early (1st) and late (5th) cutting alfalfa as ground hay, aqueous, or chloroform-extracted hay in combination with a gastrointestinal challenge to understand the effect of supplementation form and cutting on the overall health, microbiome, and immune system of mice. 163 C57BL/6J mice were housed for 35 d (Innovive system; 2–4 mice/cage) and fed treatments that consisted of an 18% protein rodent diet (alfalfa-free control), or control supplemented with 1st or 5th cutting 9% ground alfalfa hay, 0.25% aqueous extract (AAE), or 0.25% chloroform extract (CAE). After a 14 d enrichment period, 6 mice/treatment were euthanized for baseline tissue and digesta sampling, and remaining mice were orally gavaged with 2x1010 CFU Citrobacter rodentium. On d18, 22, 28, and 35, 4 mice/treatment were euthanized for sampling. Body weight (BW) and feed intake (FI) were recorded, 13 serum cytokines were measured, and changes in the microbial communities were analyzed using 16S rRNA amplicon sequencing. Data were analyzed using PROC MIXED and linear discrimination analysis effect size (LEfSe), with significance at P ≤ 0.05. No BW differences were observed between treatments at the key timepoints (P > 0.05). Mice fed hay diets ate 16% more per day during the enrichment period (P = 0.03), 19% more from d14–18 (P = 0.001), and 17% more from d18–22 (P = 0.03) versus mice fed AAE. Citrobacter rodentium infection was confirmed via MiSeq in colon digesta. Significant shifts in microbial taxa were observed in mice fed alfalfa hay regardless of cutting (P < 0.05). Cytokine analysis, flow cytometry, and microbiome analysis is ongoing. Preliminary results show that alfalfa form significantly impacts FI and microbiome while cutting impacts weight (P < 0.05).
81 Increasing withdrawal duration of corn distillers dried grains with solubles on finishing pig performance and carcass characteristics
Authors: Lerner Annie B , Tokach Mike D , Woodworth Jason C , DeRouchey Joel M , Dritz Steve S , Goodband Robert D , Allerson Matt W
Published: July 2019

A total of 860 finishing pigs (PIC C48/L42×327; initially 66.2 kg BW) were used in a 76-d experiment to evaluate the effects of removing corn DDGS from diets at increasing intervals before harvest. Diets contained 40% DDGS prior to the experiment, 0 or 35% DDGS during the experiment from approximately 66 to 82 kg and 0 or 30% DDGS until the completion of the trial. Pen served as the experimental unit, and there were 7 replicate pens/treatment with 23 to 25 pigs/pen. Pens were blocked by BW and allotted to 1 of 5 dietary treatments, differentiated by the number of days prior to slaughter that diets containing DDGS were withdrawn and replaced with corn-soybean meal-based diets. Withdrawal times were 76, 42, 27, 15, or 0 d (no withdrawal) before harvest. Linear and quadratic response to withdrawal time was evaluated using PROC GLIMMIX. For the overall period (d -76 to 0), as time of DDGS withdrawal increased, ADG and final BW also increased (linear, P < 0.018) and G:F improved (quadratic, P = 0.019). Average daily feed intake quadratically decreased (P = 0.030) with increasing withdrawal time. There was a linear increase (P = 0.010) in HCW, with a marginally significant increase in carcass yield (linear, P = 0.094) with increasing DDGS withdrawal time. Loin depth and lean percentage did not demonstrate any evidence for treatment differences (P > 0.132). Backfat was linearly increased (P = 0.030) with increasing DDGS withdrawal time. Lastly, iodine value (IV) of belly fat was increased (linear, P = 0.001) with increased feeding duration of DDGS. In conclusion, removing pigs from diets containing DDGS for longer periods before slaughter increased ADG and improved G:F, resulting in increased HCW. Belly fat IV was decreased as the length of DDGS withdrawal increased, with the highest IV resulting from pigs that consumed DDGS for the entire experimental period.
84 Improving dietary amino acid balance reduces heat production in lactating sows exposed to heat stress
Authors: Zhang Sai , Johnson Jay S , Trottier Nathalie L
Published: July 2019

We hypothesized that lactating sows fed a reduced CP (RCP) diet with supplemental AA to improve AA balance produce less metabolic heat (HP) compared with feeding a conventional diet (control). The objective was to measure HP of sows (n = 24) fed control (19.6% CP) or RCP (14.2% CP) under thermoneutral (TN, 21 ± 1.5°C) or cycling heat stress (HS, 32 ± 1.5°C daytime and 24 ± 1.5°C nighttime). Diets contained 0.90% SID Lys and 2,580 kcal/kg. Positive pressure indirect calorimeters were used to measure gas exchange in individual sows with litters (sow + litter), and individual piglets on lactation d 4, 8, 14 and 18, and HP determined overnight (1900–0700) and during daytime (0700–1900). Sow and litter weights were recorded on d 1, 10 and 21. Sow HP was calculated by subtracting litter HP from sow + litter HP based on BW0.75. Model included the fixed effect of diet, random effects of block and sow, sow feed intake as a regression variable and day as the repeated measurement. Compared to control, HP (kcal/h·kg0.75) of RCP was lower (P < 0.01) overnight (5.25 vs. 5.96 ± 0.38), during daytime (6.33 vs. 6.94 ± 0.23), and over 24-h (5.78 vs. 6.46 ± 0.24) under HS. Under TN, HP of RCP tended to differ (P = 0.107) overnight (5.20 vs. 5.90 ±0.57) and over 24-h (5.93 vs. 6.48 ± 0.50) and did not differ (P = 0.190) during daytime (6.66 vs. 7.06 ± 0.52). Under HS, lactation day affected HP (P < 0.05) overnight and over 24-h, with HP increasing from d 1 to 14 and decreasing from d 14 to 18. Under TN, day of lactation did not affect sow HP. Feeding RCP diet to lactating sows decreased HP, and this effect was more pronounced in sows housed under HS.
86 Impact of steeping corn DDGS over 72 hours without or with fiber degrading enzymes and protease alone or in combination on concentration of sugars and organic acids and pH in the liquid medium
Authors: Rho Youngji , Patterson Rob , Kiarie Elijah
Published: July 2019

We investigated the impact of steeping corn DDGS over 72 h with or without fiber degrading enzymes (FDE) and protease (PRO) on concentration of sugar, acetic and lactic acid, and pH. The concentration of crude fat, CP, NDF and ADF in DDGS sample was 8.6, 30.8, 36.1, 12.2% DM, respectively. Treatments were: 1) DDGS steeped without enzymes (Control), 2) DDGS steeped with FDE (FDE), 3) DDGS steeped with protease (PRO), 4) DDGS steeped with combination (FDEPRO). Enzymes were added at 1% of DDGS. Briefly, 50g of DDGS was mixed with 500-mL water with or without enzymes in sterile plastic bottles and steeped for 0, 12, 24, 48 and 72-h at 37℃ with continuous agitation. Samples were aliquoted to individual bottle for each timepoint. At each time point, bottles were pulled out from the incubator for pH measurements and liquid medium supernatant for sugars and acids. Highest arabinose, xylose and glucose was observed at 12 and 24 h, followed by decrease at 48 and 72 h. At 12 h, arabinose was higher (P < 0.05) for FDE and FDEPRO than control. The highest xylose and glucose was seen at 12 h for PRO, FDE and FDEPRO while control was highest at 24 h. Acetic acid and lactic acid increased over time. At 72 h, FEDPRO had highest acetic acid compared to control and PRO, while lactic acid was highest for FDE and FDPRO compared with (P < 0.0001) control and PRO. The pH decreased (P < 0.05) over time for all treatments. At 72 h, FDE had lowest pH followed by FDEPRO, PRO and control (P < .0001). Overall, arabinose, xylose and glucose increased to a certain timepoint and decreased, while lactic and acetic acid increased over time, subsequently leading to lowest pH at 72 h. In conclusion, FDE increased concentration of sugars and acids in steeped DDGS whereas PRO had no effect.
94 Dietary soy isoflavone ingestion alters the acute and recovery immune responses in growing pigs infected with porcine reproductive and respiratory syndrome virus
Authors: Smith Brooke N , Oelschlager Maci , Hannas Melissa , Rasheed Muhammad Shameer Abdul , Dilger Ryan
Published: July 2019

Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically-important disease and ingestion of soy isoflavones (ISF) may benefit PRRSV-infected pigs due to demonstrated anti-inflammatory and anti-viral properties. The objective of this study was to determine long-term effects of feeding ISF on growth performance and both acute and recovery immune responses following PRRSV infection. In total, 96 weaned barrows were group-housed in a BSL-2 containment facility and allotted to 1 of 3 experimental treatments that were maintained throughout the study: non-infected pigs received an ISF-devoid control diet (NC, n = 24), and infected pigs received either the control diet (PC, n = 36) or that supplemented with total ISF in excess of 1,600 mg/kg (ISF, n = 36). Following a 7-day adaptation, weanling pigs were inoculated intranasally with either a sham-control (PBS) or live PRRSV (1×105 TCID50/mL, strain NADC20). After inoculation, individual blood samples (n = 8–12/treatment) were routinely collected to monitor viral clearance, hematological parameters, and anti-PRRSV antibody production, and pen-based oral fluids were used to monitor PRRSV clearance at later growth stages. A 2-way ANOVA (including time effect) was performed to compare NC and PC groups (infection status) and PC and ISF groups (ISF effect within infected pigs). In general, PRRSV infection decreased performance during early growth phases, resulting in 5.4% lower final BW for PC vs. NC pigs (P < 0.05). Dietary ISF elicited inconsistent effects on growth performance, reduced (P < 0.05) longitudinal serum viral loads, and increased (P < 0.05) the rate of PRRSV clearance from oral fluids. Dietary ISF also elicited earlier, more robust anti-PRRSV neutralizing antibody production as compared with PC pigs. Additionally, PC pigs experienced ~50% greater infection-related mortality vs. ISF pigs (P < 0.05), which could have significant economic implications for producers. Overall, dietary ISF ingestion supported immune responses and reduced mortality in PRRSV-infected pigs when fed to growing pigs.
92 Intra-nasal oxytocin treatment does not attenuate the hypothalamo-pituitary-adrenal axis in beef heifers subjected to isolation stress or restraint and isolation stress
Authors: Wagner Brooklyn , Relling Alejandro E , Kieffer Justin , Parker Anthony
Published: July 2019

Changes in the physiological, psychological, and behavioral manifestations of stress are observed in association with increases in circulating oxytocin. Providing oxytocin intra-nasally attenuates stressor-induced hypothalamo-pituitary-adrenal (HPA) axis activation in humans and rodents. The present study was conducted to investigate effects of intra-nasal oxytocin supplementation on stressor-induced activation of the HPA axis in beef cattle. We hypothesized that oxytocin would attenuate activation of the HPA axis, ultimately decreasing plasma cortisol. Bos taurus heifers (n = 28) were blocked by bodyweight and randomly allocated to one of four treatment groups, in a 2 × 2 factorial arrangement: 1) Saline, isolated, standing, and unrestrained (S-IS, 0.015mL/kg BW 0.9% isotonic saline, n = 7); 2) Saline, isolated, and restrained (S-RIS; 0.015 ml/kg BW 0.9% isotonic saline; n = 7); 3) Oxytocin, IS (OXT-IS, 0.3 IU/kg BW oxytocin; n = 7); and 4) Oxytocin and isolated and restrained (OXT-RIS, 0.3 IU/kg BW oxytocin; n = 7). Oxytocin and saline were administered intra-nasally. Appropriate stressors were applied 30 minutes following intra-nasal treatment. Blood samples were collected directly following imposing the stressor, and every 10 minutes thereafter, for 2 h. Cortisol concentrations increased over time in animals exposed to restraint and isolation stress (P < 0.01) and decreased over time in animals exposed to isolation stress (P < 0.01). In the present study, oxytocin did not affect measured indicators of HPA axis activation. Greater plasma oxytocin concentrations were observed in restrained animals administered saline, compared with their standing counterparts administered oxytocin (P < 0.01), indicating some endogenous release of oxytocin in response to restraint stress. Overall, restraint stress increased cortisol and oxytocin in Bos taurus heifers compared with heifers subjected only to isolation. Finding a more intermediate stress model may allow for more precise detection of effects of oxytocin on the stress response.
98 Final internal cooking temperature of pork chops influenced consumer eating experience more than visual color and marbling
Authors: Honegger Lauren T , Richardson Elaine , Schunke Emily D , Dilger Anna C , Boler Dustin D
Published: July 2019

The objective was to determine the effect of ultimate pH or “quality grade” (combination of color and marbling) on consumer eating experience of pork chops cooked to different final internal temperatures. The hypothesis was that consumers would rate a greater percentage of pork chops as acceptable with a greater pH, when graded “choice”, or when cooked to 63°C compared with 71°C or 82°C. Consumers (264 total) were served chops in 1 of 2 experiments. Experiment 1 assessed chops as high pH (6.23–5.88) or low pH (5.36–5.56) and cooked to 63°C, 71°C or 82°C. Experiment 2 classified chops as “choice” when NPPC color score ≥ 3 and marbling score was ≥ 2 or “standard” when NPPC scores were below “choice” and cooked to 63°C or 71°C. Chops were cooked with an immersion heater (ANOVA Precision Cooker, Anova Applied Electronics, San Francisco, CA) in a water bath. Consumers used a 9-point Likert-type score system where 1 was extremely tough, dry, bland, or unacceptable and 9 was extremely tender, juicy, flavorful, or acceptable. Data were organized as a percentage of responses and analyzed using the GLIMMIX procedure of SAS for both experiments with models including treatment (pH or quality grade category, temperature and all interactions). More (P < 0.01) consumers scored chops at 7, 8, or 9 for juiciness with a high pH (36.07%) compared with chops with a low pH (24.29%), but pH category did not alter other traits (P ≥ 0.13). Quality grade did not affect (P ≥ 0.30) consumer ratings of any sensory trait. In both studies, a greater (P < 0.001) percentage of consumers rated chops cooked to 63°C as acceptable compared with chops cooked to 71°C. Therefore, internal cooking temperature has a greater impact on consumer eating experience than ultimate pH or “quality grade.”
102 Developing Industry-Relevant Academic Research Programs in Meat Science
Authors: Gredell Devin , Rode Heather , McKenna David
Published: July 2019

A synergistic relationship exists between the meat industry and meat science academic programs, leading to frequent collaboration between the two groups. This not only provides applied experience for students, but also allows the meat industry to utilize resources unique to academia and align academic research efforts to address industry issues. The meat industry is driven by efficiency; generally requiring ideas to be further along in development before thoroughly considering the incorporation of new ideas or technologies. This can lead to valuable improvements being overlooked simply because their full potential has not been previously demonstrated. In contrast, the university setting encourages the development of new ideas from the ground up. Therefore, academic research has frequently been the source of innovative concepts that have later been adopted by industry as common practice. It is this link between conceptualization and commercialization of new ideas that makes relationships between academic and industry scientists so valuable. By maintaining these relationships, the meat industry can express areas for improvement and innovation, so that academic scientists can adapt their research programs to address industry-relevant concerns. This not only fills a void in the industry research and development process but also provides funding opportunities for academic scientists, both directly from industry and from trade organizations funding academic research on behalf of industry members. Changes in the diversity of market animals, increased consumer interest in production history, labor shortages, and increased concern for sustainable food production only describe a few of the challenges facing the meat industry. To rise above these challenges, collaboration between industry and academia will undoubtedly be necessary. This session will focus on current and future areas of interest to promote industry-focused research within meat science academic programs.
103 Research needs for the development of the pork industry
Authors: Fields Brandon , Matthews Neal , Bloemhof Saskia , Fitzgerald Rob , Sosnicki Andrzej
Published: July 2019

Global demand for pork and pork products is increasing, as is competitive pressure throughout the industry. Therefore, pork producers and processors must continue to become more efficient and innovative while focusing on evolving consumer demands. To do so, a strong research focus is needed by all involved. Traditionally, academia has focused its research on the basic science, while industry has worked to apply that scientific information into everyday practice. In the future, academia and industry will need to align to develop understanding, tools, and technology that are both meaningful for everyday use and practical to implement in production and genetic improvement programs. Understanding the fundamental biology of skeletal muscle and the interaction with the environment is the foundation, and this includes an understanding of embryonic development all the way through aging of fresh pork products. We must better understand both the pre-slaughter factors influencing the conversion of muscle to meat as well as the post-mortem biochemistry that underlies pork quality development. Moreover, a method of grading pork quality at line speeds of near 1500 / hr, and with traits that guarantee an enjoyable eating experience, will cement pork as the meat of choice to the consumer. Lastly, genetic improvement is allowing pigs to grow faster and heavier than ever, while still maintaining leanness and desirable eating quality. However, heavier pigs are often met with resistance by the processor and consumer as traditional cuts simply become “too big” for the average portion. New methods of cutting and processing a pork carcass, and increased understanding of whole muscle cut profiles that can be turned into new and exciting products for the consumer, are a major key to unlocking the total value of the pig for future producers and consumers alike.
104 Gene editing in livestock: advancements, opportunities and challenges
Authors: Dilger Anna C
Published: July 2019

Genetic engineering of animals, or the alteration of an animal’s genetic code by exogenous manipulation, dates from the mid-1970s. Using these techniques, many transgenic animals were created as models for human diseases or to further agricultural and biomedical research, but barriers that slowed the approval of these animals for food production hampered their development in livestock. However, with the advent of gene editing in the last ten years, there is renewed interest in genetic modification of livestock to improve productivity, efficiency or product quality. Unlike genetic engineering, gene editing does not rely on the introduction of exogenous DNA; instead, double-stranded breaks in DNA are induced in targeted genes and mutations occur due to the endogenous repair mechanisms present in organisms. Small sequences of exogenous DNA can also be introduced in this process, if desired. Gene editing is more efficient and more targeted than genetic engineering, resulting in increased yields of cells with the desired mutation. Recent advancements in gene editing include the generation of pigs resistant to porcine reproductive and respiratory syndrome virus due to a mutation in CD163, a mutation in the SP110 gene resulting in cattle with lower susceptibility to tuberculosis, and alterations that lead to polled cattle, eliminating the need for dehorning. However, these advancements are not without their challenges. Chief among them are poor consumer acceptance of meat, milk and eggs from gene-edited animals and the inconsistent and complicated regulatory environment involving these products. Additionally, challenges exist in the production of these animals due to unintended consequences from induced mutations. Stated plainly, making a gene-edited animal is rarely as simple as it seems. However, if these challenges can be overcome, gene editing holds promise for rapid improvement in germplasm to rapidly increase productivity and sustainability of livestock species.
109 Mature cow size and impacts on cow efficiency
Authors: Lalman David , Beck Paul A
Published: July 2019

According to genetic trend data, mature BW in beef cows continues to increase although the pace is slowing. This change is not increased frame size as the genetic trend for mature height in Angus cattle has been flat since about 1995. In sell-at-weaning enterprises, calf value at weaning must accompany increased cow size to justify the added expense of larger cows. We used the California Net Energy System and NASEM (2016) equations to estimate the annual cost to maintain beef cows varying in mature size. Maintenance energy requirements were assumed to be 77 kcal per kg of metabolic body weight plus 20% during lactation. Reproductive efficiency and average daily milk production was assumed to be equal among the two mature cow BW scenarios. In ranching operations with average mature cow BW of 556 kg and annual feed and grazing costs of $400, $500, $600 or $700, increasing average mature BW by 90.8 kg resulted in increased projected annual feed and grazing cost of $41.05, $51.32, $61.58 and $71.84 per cow, respectively, or about 10%. Estimated differences in variable costs (labor, depreciation, etc.) were minor for the larger cow herd. Assuming an annual replacement rate of 16% and cull cow price of $1.32 per kg, cull cow income would increase by approximately $19.20 per cow per year in the larger cow scenario. Consequently, to break even with the 556 kg mature cow BW scenario, sell-at-weaning enterprises with average mature cow BW of 647 kg must achieve $21.85, $32.12, $42.38, or $52.64 increased calf value depending on average annual cow cost. These estimates of increased income required to offset increased mature cow BW are conservative because no cost was assigned to grow the additional 90.8 kg of cow BW.
114 Role of fiber in promoting health in nursery pigs
Authors: Zijlstra Ruurd T , Fouhse Janelle M , Heyer Charlotte Maria Elisabeth , Tan Felina , Vasanthan Thavaratnam , Beltranena Eduardo , Gänzle Michael G
Published: July 2019

In swine production, use of feed antibiotics as antimicrobial growth promotant will be reduced; thus, feed alternatives to manage gut health are required to prevent post-weaning diarrhea. Dietary fiber, resistant starch, oligosaccharides, and exo-polysaccharides are carbohydrates are nutritional tools that may be part of managing gut health in pigs. Antibiotics are hypothesized to influence gut health via modulation of intestinal microbial profiles; fermentation and intestinal inflammation are considered important mechanisms. As alternative, dietary fiber sources differ in 2 key properties: fermentability and viscosity. Rapid fiber fermentation is associated with changes in microbial profiles and increased metabolite production. Recently, microbial composition was hypothesized to be less important, and it was thought that the focus should be on combined output of metabolites. Increased viscosity has been associated with increased gut content of virulence factors linked with diarrhea. Fiber properties may manipulate retention time and physico-chemical properties of the undigested residue. Starch is mostly digested and absorbed as glucose; however, resistant starch is not digested but fermented instead. Resistant starch acts as fermentable fiber but is unique, because it specifically increases digesta abundance of bifidobacteria that are associated with improved gut health. Oligosaccharides may be rapidly fermented and thereby influence intestinal microbial profiles and metabolite production. Raw materials and some feed additives both influence kinetics of fermentation and have prebiotic activity. Their kinetics of fermentation should be quantified so that it can be considered in feed formulation. Finally, exopolysaccharides from Lactobacillus reuteri and unique oligosaccharides may serve as scavenger molecules for pathogenic bacteria, e.g., enterotoxigenic Escherichia coli (ETEC), to bind to instead of adhering to the gut wall, thereby avoiding diarrhea initiation. In conclusion, dietary fiber and other carbohydrates may be important solutions to maintain gut health when antibiotics are removed as growth promotants from swine feeds.
119 Bioavailability of L-Methionine in comparison to DL-Methionine for nitrogen retention of weaned and growing pigs
Authors: Caetano Raphael P , Santos Luan S , Htoo John K , Veira Alini M , Silva Welex C , Gobi Jaqueline P , Fraga Alicia Z , Campos Paulo H R F , Barbosa Nei A A , Hauschild Luciano
Published: July 2019

Two nitrogen (N) balance studies were conducted to compare the relative bioavailability (RBV) of L-Met with DL-Met as Met sources in young pigs. In each experiment, 42 barrows (PIC; initial BW in Exp. 1: 10.7 kg and Exp. 2: 20.5 kg) were allotted to 7 experimental diets with 6 pigs per treatment. The basal diets (diet 1) were formulated based on corn and soybean meal being deficient in Met, but adequate for the other AA (Exp. 1: 0.24% standardized ileal digestible [SID] Met; 0.53% SID Met + Cys; 1.30% SID Lys; Exp 2: 0.23% SID Met; 0.47% SID Met + Cys; 1.15% SID Lys). Three graded levels of DL-Met and L-Met (0.03, 0.06 and 0.09%) were supplemented to the basal diet on top to create diets 2 to 7 for both studies. In Exp.1, N retention (% of N absorbed) increased linearly (P < 0.05) with supplementation with both Met sources. The slope-ratio regression estimated the RBV of 106% [95% confidence interval (CI): 39 to 173%] for N retention (% of absorbed) on an equi-molar basis. In Exp. 2, N retained (g/d), N retention (% of N intake and % of N absorbed) increased linearly (P < 0.05) by supplementing with both Met sources. There was no effect of Met sources on all N balance parameters in both studies. The slope-ratio estimated the RBV of 89% (95% CI: -28 to 206%) for N retained (g/d), 95% (95% CI: 13 to 177%) for N retention (% of N intake) and 94% (95% CI: 20 to 167%) for N retention (% of N absorbed), respectively on an equi-molar basis. In conclusion, the 95% CI for the RBV of L-Met covers 100%, indicating the RBV of L-Met is not different from that of DL-Met as a Met source for weaned and growing pigs.
117 Determining high-lysine sorghum amino acid digestibility and the effects on nursery pig performance
Authors: Thomas Lori L , Goodband Robert D , Espinosa Charmaine D , Stein Hans H , Woodworth Jason C , Tokach Mike D , Dritz Steve S , DeRouchey Joel M
Published: July 2019

Two experiments determined the SID of AA in a high-lysine sorghum cultivar, followed by a growth trial to determine its effects on pig performance using increasing feed-grade AA at the expense of soybean meal. In Exp. 1, ten barrows (initially 25.9 kg) were surgically fitted with a T-cannula at the terminal ileum and randomly assigned to 1 of 5 diets in a 5-period, cross-over design. Experimental diets included a corn-based diet, a diet containing high-lysine sorghum, or two diets with either white or red sorghum cultivars. The fifth experimental diet was N-free to determine endogenous AA loss. In corn, SID CP, lysine, methionine, threonine, and valine were greater (P < 0.020) than sorghum-based diets, with no evidence for differences among the sorghum cultivars. In Exp. 2, a total of 293 pigs (initially 9.6 kg) were used. Dietary treatments were randomly assigned 20 d after weaning and consisted of a corn-based diet, a diet based on conventional sorghum, and 4 diets with high-lysine sorghum with 10 replications/treatment. The corn-based, conventional sorghum, and the first high-lysine sorghum (low) diets each contained the same amount of soybean meal with varying amounts of feed-grade AA. The 3 remaining high-lysine sorghum diets included incrementally increasing amounts of feed-grade AA (low-medium, medium-high, and high), replacing soybean meal. Overall, there was no evidence for differences in ADG or ADFI between treatments. However, pigs fed the high-lysine sorghum with the greatest amount of feed-grade AA had decreased G:F (P = 0.045) compared with those fed other experimental diets. In summary, SID AA values for the high-lysine sorghum in this study were not different from sorghum cultivars; however, these values were all lower when compared with corn. When nursery diets were formulated on an equal SID AA basis, there were no differences in ADG among pigs fed any of the diets.
116 Direct vs. difference method to determine amino acid digestibility in ingredients fed to pigs
Authors: Faria de Oliveira Maryane S , Htoo John K , Stein Hans H
Published: July 2019

An experiment was conducted to test the hypothesis that values for standardized ileal digestibility (SID) of amino acids (AA) in cereal grains and fiber rich ingredients obtained using the direct method are not different from values obtained using the difference method. Sixteen ileal-cannulated barrows (69.45 ± 5.01 kg) were allotted to an 8 diets × 4 period Youden square design. Each period consisted of 5 d of adaptation and 2 d of ileal digesta collection. Four diets were based on soybean meal (SBM), corn, wheat, or wheat middlings as the only AA-containing ingredients. Three additional diets were based on a mixture of SBM and corn, wheat, or wheat middlings and a N-free diet was also used. The SID of AA in the 4 diets containing SBM, corn, wheat, or wheat middlings as the sole source of AA were calculated using the direct method. The SID of AA in corn, wheat, and wheat middlings were also calculated by difference from the 3 diets containing SBM and corn, wheat, or wheat middlings by subtracting the contribution from SBM of each AA from the SID values for the mixed diet. Data were analyzed using a model that included the method of determination of AA digestibility as the fixed effect, and pig and period as random effects. There was no difference between the direct and the difference method for the SID of most AA in corn, wheat, and wheat middlings, although the SID of Trp was lower (P < 0.05) for the difference method than values derived by the direct method for both corn and wheat middlings (Table 1). Therefore, values for SID of AA in cereal grains or fiber-rich ingredients could be obtained using either the direct method or the difference method.
123 Growth performance and nutrient digestibility of multi-enzyme-supplemented low-energy and -amino acid diets for growing and finishing pigs
Authors: Jerez Bogota Kevin S , Sanchez Christian , Ibagon Jimena , Jlali Maamer , Cozannet Pierre , Preynat Aurélie , Woyengo Tofuko A
Published: July 2019

Objective was to determine the effects of supplementing corn-soybean meal-based diets with a multi-enzyme on growth performance and apparent total tract digestibility (ATTD) of nutrients in growing pigs. A total of 276 pigs (BW = 33.99 ± 4.3 kg) were housed by sex in 45 pens of 6 or 7 pigs and fed 5 diets (9 pens/diet) in a randomized complete block design. Diets were positive control (PC); and negative control 1 (NC1) or negative control 2 (NC2) without or with multi-enzyme. The multi-enzyme used supplied at least 1,250, 860, 4,600, and 1,000 units of xylanase, β-glucanase, arabinofuranosidase and phytase per kilogram of diet, respectively. The PC was adequate in all nutrients according to NRC (2012) recommendations and had greater digestible P content than NC1 diet or NC2 diet by 0.134 percentage points. The NC1 diet had lower NE and digestible AA content than PC diet by 3%. The NC2 diet had lower NE and digestible AA content than PC diet by 5%. The diets were fed in 4 phases based on BW; Phase 1: 34–50 kg, Phase 2: 50–75 kg, Phase 3: 75–100 kg, and Phase 4: 100–120 kg. Nutrient digestibility was determined at the end of Phase 1. Overall (34–120 kg BW), pigs fed the PC and NC1 diets did not differ in ADG and ADFI. Pigs fed NC2 diet had lower (PPPP > 0.10). Supplemental multi-enzyme increased (P = 0.047) the ATTD of GE for NC2 diet. In conclusion, the NE and digestible AA and P can be lowered by ≤ 5% in multi-enzyme-supplemented diets without effects on growth performance pigs.
129 The effect of Activo Liquid supplemented via the water against Mecadox 50 on nursery pig’s growth performance and survival
Authors: Cabrera Rafael A
Published: July 2019

The objective of this study was to compare Activo Liquid supplemented via the water agaisnt Mecadox 50 on nursery pigs’ growth performance and survival. Activo Liquid is a combination of secondary plant compounds plus organic acid (antimicrobial) supplemented in the water to support gut health and improve performance. The study design of this trial was a Split Plot with 36 replicates (9 replicates/treatment) with 10 pigs/pen. Pigs were allotted by a Randomized Complete Block Design by weight at weaning. Pigs were around 5.7 kg and 19 days of age average on body weight and weaning age, respectively. The nursery houses were not washed for two turns to expose the animals to serious pathogens. The data were analyzed by analysis of variance with pen as the experimental unit. Significant differences were established by P < 0.05. Treatments were Control with 50g/ton of Mecadox for all nursery phases and three Activo Liquid treatments (6 oz per 128 gallon of drinking water administered either for 3, 5 or 7 days post-weaning). A typical nursery feeding program was followed: Phase 1 from d 0 to d 7, Phase2 from d 8 to d 21 and Phase 3 from d 22 to d4 2. They contain 23%, 21% and 19% crude protein respectively. The results showed no significant difference on final body weight among the treatments. All Activo treatments had improved (P < 0.05) feed conversion (Feed:Gain) when compared with the medicated treatment. Activo Liquid 5d treatment post-weaning had numerically lower mortality when compared with all the other treatments. In conclusion, the results of this trial showed that the supplementation of Activo Liquid for 5 d post-weaning at 6 oz/128 gallon of water can safely replace Mecadox 50 g/ton. More research is needed to validate the repeatability of these results and understand Activo Liquid’s mode of action as a powerful antimicrobial.
136 The impact of Swine Awake® on commercial nursery flows from a PRRSV positive source
Authors: Sugg Emily , Jones Randy , Holck Tyler , Heintzelman Scott , Weiland Sarah A
Published: July 2019

The objective of this study was to evaluate the impact of Swine Awake® (SA; NutriQuest, Mason City, IA) on commercial nursery pigs from a single-source positive for Porcine Reproductive and Respiratory Virus (PRRSV). This study included 16 nursery rooms located on 3 farms. Rooms were alternately assigned between Control and SA treatment for a total of 8 rooms per treatment, with both treatments equally represented at each farm. Control and SA treatment rooms averaged 1,144 and 1,125 pigs placed for 47.4 and 48.3 days on trial, respectively. Swine Awake was administered via water for 21 d post-placement. Serum samples were collected from 30 pigs in each room at placement before MLV PRRSV vaccination and pooled in groups of 5 within room. Pooled serum samples along with oral fluid samples pulled the last days of trial were sent for PRRSV quantification by PCR. Performance data were analyzed using the MIXED procedure of SAS. Farm, start BW, and days on trial were used as covariates in the model when significant (P < 0.05). Twenty-seven of 96 pooled serum samples and 29 of 30 oral fluid samples tested positive for PRRSV with CT values ranging from 26.2 to < 37, suggesting pigs were viremic at placement with virus present throughout the study. End BW, ADG, and G/F did not significantly differ between treatments (P > 0.10); however, a numerical improvement of 0.27 kg for end BW and a 1.9% improvement in G/F were observed for pigs given SA compared with Control. Reduced percentage of dead or euthanized pigs was observed for pigs given SA compared with Control (4.1 vs. 5.9%, P = 0.06). Overall, nursery growth performance in pigs coming from a PRRSV positive flow was not different between treatments, but total mortality was decreased by 31% in barns where SA was administered.
142 Effects of antibiotics on blood profiles in weanling pigs experimentally infected with a pathogenic E. coli
Authors: Kim Kwangwook , He Yijie , Jinno Cynthia , Yang Seijoo , Song Minho , Ji Peng , Liu Yanhong
Published: July 2019

The experiment was conducted to investigate the effects of antibiotics on blood profiles and serum inflammatory mediators of weaned pigs experimentally infected with F18 Escherichia coli (E. coli). Twenty-six pigs (6.88 ± 1.03 kg BW) were individually housed in disease containment rooms and randomly allotted to one of three treatments with 8–12 replicate pigs per treatment. The three dietary treatments were control diet and 2 additional diets supplemented with 0.5 or 50 mg/kg carbadox, respectively. The experiment lasted 18 d (7 d before and 11 d after first inoculation [d 0]). F18 E. coli inoculum was daily and orally as 1010 cfu/3 mL for 3 d. Blood samples were collected before E. coli inoculation and on d 2, 5, 8, and 11 post-inoculation (PI). Total and differential blood cell count were analyzed by CBC test. All data were analyzed by ANOVA using PROC MIXED of SAS. Supplementation of low-dose antibiotics had greatest (P < 0.05) neutrophils but lowest (P < 0.05) monocytes on d 2 PI, compared with control and high-dose antibiotics groups. Pigs in the low-dose antibiotics group still had higher (P < 0.05) white blood cell counts and lymphocytes than pigs in the other groups on d 11 PI. In consistent with CBC results, pigs supplemented with low-dose antibiotics had greatest (P < 0.05) serum C-reactive protein on d 2 and 5 PI and serum TNF-α on d 5 PI, compared with pigs in the control and high-dose antibiotics groups. No differences were observed in the red blood cell profiles between pigs in control and low-dose antibiotics groups, whereas supplementation of high-dose antibiotics had lowest (P < 0.05) packed cell volume but highest (P < 0.05) mean corpuscular hemoglobin concentration among three treatments. In conclusion, low-dose antibiotic supplementation may exacerbate systemic inflammation caused by F18 E. coli infection.