bluuebunny/crossref_metadata_2025 huggingface dataset:
286 Where Is On-farm Animal Welfare in the United States Headed? A Canadian Perspective
Authors: Brown Jennifer
Published: May 2021

Both the United States and Canada are major exporters of pork, with market forces and consumer demand playing a more important role than legislation in defining production standards. Canadian welfare standards can be seen as intermediate between those in America and Europe, with the province of Quebec leading the way in Canada’s production of “high welfare” pork. In many other respects- such as farm size, diets, genetics and management, pig farms in Canada and the United States are very similar. What can U.S. producers learn from Canada’s experience in implementation of new welfare standards? This talk discusses Canada’s 2014 implementation of the Code of Practice for the Care and Handling of Pigs. The Code included multiple new requirements, including the transition to group housing for gestating sows, use of analgesics at castration and tail docking, space allowances and the provision of enrichment. Code development is overseen by the National Farm Animal Care Council (NFACC) in cooperation with the Canadian Pork Council (CPC) and with participation of government, industry and public partners. In 2020, the Pig Code underwent a 5-year review, which resulted in eight major recommendations. Five of those recommendations will require amendments to the code and are yet to be approved. Each change illustrates a balance between economics and welfare in a highly competitive and changing industry. For example, the 2014 Code promoted adoption of group housing for sows by July 1, 2024. While integrated production systems committed to, and invested heavily in, implementation of group gestation, the cost of barn conversion and poor pork returns have been major deterrents on many farms. The CPC estimates that in 2021, 44% of Canada’s sow herd will be managed in groups. The Code review recognized that not all producers will be able to transition by 2024, and that forcing producers to convert on a strict timeline would result in a worsening of the animal’s welfare. The review recommended changing the date for implementation of group housing from 2024 to 2029. This more gradual transition will allow renovations to be part of a scheduled rebuild of an existing facility or new construction, with better long-term outcomes for producers and sow wellbeing.
285 Panel: Recent Practical Advancements Related to On-farm Animal Welfare in the United States
Authors: Baysinger Angela , Ayers Paul , Wisdom Stephanie , Holt Jon P
Published: May 2021

The purpose of this panel session is to highlight recent practical solutions and advancements to farm animal welfare challenges in the United States. Through a moderated discussion with session attendees, professionals and experts representing a variety of livestock industry and academic sectors will be given the opportunity to share their professional experiences in working to improve animal welfare by highlighting examples of practical solutions they have undertaken. Additionally, a discussion will be held on the future direction of farm animal welfare needs and barriers to implementation of animal welfare-related strategies.
283 Timely Euthanasia on Farm; Dairy Cattle and Swine
Authors: Pairis-Garcia Monique , Robles Ivelisse
Published: May 2021

Euthanasia of mature swine and cattle can be challenging. On-farm euthanasia should be used as a tool to eliminate pain and suffering. However, clear guidelines regarding making euthanasia decisions and alternative euthanasia techniques available for use is limited in the United States (US). In order to prevent prolonged suffering and pain in compromised animals, science-based recommendations are needed to ensure timely and humane euthanasia can be performed when needed on-farm. This presentation will focus on two euthanasia challenges currently faced in swine and dairy cattle systems in the US today: 1) Swine: Validating alternative euthanasia techniques for use in mature breeding stock and 2) Dairy Cattle: Identifying producer barriers preventing timely euthanasia decision-making using surveys and focus groups. The swine study evaluated the effectiveness of two penetrating captive bolt gun styles (cylinder or pistol) using a frontal, temporal and behind-the-ear placement. Four treatments were 100% effective in achieving cardiac arrest and death. The cylinder style captive bolt gun resulted in greater brain trauma and death compared to a pistol style gun and behind-the-ear and temporal placement showed promise as an alternative placement site for euthanizing mature pigs. In the dairy cattle study, dairy producers were recruited to participate in a survey and focus group. Survey results indicated that farm owners were most commonly responsible for on-farm euthanasia and most respondents would treat and monitor compromised cattle for a majority of health conditions, regardless of condition severity. Participants in focus groups focused primarily on animal welfare as the most important factor influencing the decision to euthanize and the desire to eliminate animal suffering by using euthanasia as a tool. This work highlights the complicated challenges that arise when euthanizing livestock and the importance of not only identifying appropriate techniques to humanely euthanize livestock but address the emotional and animal welfare factors that influence these decisions.
10 Mechanisms by Which Amino Acids May Enhance Mineral Absorption in Animals
Authors: Goff Jesse
Published: May 2021

Both macro- and trace minerals of the diet face similar barriers to their absorption. Minerals residing in the lumen of the GI tract, whether it be the rumen, stomach, small or large intestine of an animal, have to cross the apical and basolateral membranes of enterocytes or perhaps the tight junctions between cells of the epithelium layer to enter the interstitial space below the epithelium. Once there they can diffuse into the venous blood of the GI tract in order to reach the cells of the body requiring the minerals for various functions. Considerable evidence suggests that amino acids can enhance the absorption of minerals, particularly the trace minerals. However, the exact mechanisms by which amino acids enhance mineral absorption remain elusive. In this presentation, the role dietary amino acids may play in forming ionic and hydrogen bonds with trace minerals to enhance their solubility over the absorptive epithelium is discussed. In addition, minerals covalently bonded to amino acids have been utilized as a means of enhancing trace mineral absorption, particularly for Cu, Fe, Zn and Mn. These forms of trace minerals can be more effectively absorbed than traditional sulfate forms of these minerals. It has been suggested the amino acid bonding to the trace mineral works by preventing formation of insoluble mineral complexes with dietary chelators within the lumen of the GI tract. It has also been suggested that the amino acid -mineral complex can utilize the more efficient amino acid transporters to cross the apical membrane of the enterocytes instead of the usual mineral transport mechanisms for each mineral. The evidence for each of these mechanisms will be discussed along with the possible repercussions these mechanisms might have on mineral requirements of the animal.
7 Digestive Physiology of Pigs Lecture: Past, Present and Future
Authors: Burkey Thomas , Lindemann Merlin D
Published: May 2021

Digestive Physiology of Pigs (DPP) was organized in 1979 to promote exchange of information among scientists working in swine digestive physiology and nutrition. The objective of this presentation is to provide an overview of the past, present, and future of the most important global scientific event in the fields of pig gut physiology and nutrition. To date, fourteen symposia have been conducted including the 12th International Symposium, which was held in Keystone, Colorado (DPP-2012). In order to facilitate the activities of DPP-2012, DPP-North America was established as a non-profit entity with a mission to collaborate internationally to “establish triennial venues that present the most current research and discovery information relative to digestive physiology of pigs.” Regarding DPP-2012, 403 attendees from 28 countries were in attendance, and 250 abstracts were accepted for presentation. The attendees represented academia, industry, and major swine production entities. Today, in addition to digestive physiology and nutrition, the global DPP community has evolved to include topics such as immunology, microbiology, and the use of pigs as a model for human health. As part of the global DPP community, DPP-North America continues to work with the global DPP community to establish global networks, to learn about the latest scientific discoveries, to promote academia-industry partnerships, to involve and train the next generation of scientists, and to contribute to sustainable pork systems. Since its establishment, DPP-North America has sponsored digestive physiology lectures at the annual ASAS Midwest meetings and has provided travel scholarships for North American graduate students to attend and present research at international DPP meetings.
1 Introduction: Review of the Career: Gary L. Allee
Authors: Newcomb Mark D
Published: May 2021

Gary Allee’s professional career as a swine nutritionist spans from 1972 to 2020 in the peer-reviewed publication record. An evaluation of the major themes presented in his publications show a connectivity of work done at a “basic” science level leading to work on the application of this basic knowledge to meet pig production needs. It is interesting to explore the themes of Dr. Allee’s work and connect that to how pigs are fed on a practical basis today. Regarding sow nutrition work, Dr. Allee used his early work on lipogenesis to expand on the topic to understand how energy sources are able to cross the placental barrier and ultimately impact neonatal energy reserves. Further, Dr. Allee responded to availability changes in synthetic amino acids to the industry to explore opportunities to leverage these AA’s into sow diet formulations. In the area of nursery pig nutrition, his record explores the theme of lipid metabolism from lipogenesis, to ketogenesis to fat source and fatty acid profile implication to diet value. However, Dr. Allee picked up the themes of protein and lactose sources and implications on hypersensitivity and value of proteins and sugars targeted to the young pig all influencing practical diet formulations globally in young pig nutrition. In the area of the grow-finish pig, Gary’s work explored topics of dietary fat use, practical aspects of amino acid inclusion and the interaction of repartitioning approaches to lean deposition with nutrient requirements. This symposium is designed to highlight several key principals for success as a scientist that are evident in Dr. Allee’s career: a) importance of being a systems thinker in ability to take basic information and evolve it into practical implications; b) importance of being a global citizen in scientific professional development; and c) the impact that one has on people endures.
127 Antibody Response as an Indicator Trait for Improved Reproductive Performance During a PRRSV Outbreak: Genetic Correlations of S/P Ratio with Reproductive Traits in Landrace and Duroc Sows
Authors: Hickmann Felipe , Neto José Braccini , Kramer Luke M , Gray Kent A , Huang Yijian , Dekkers Jack C , Sanglard Leticia P , Serão Nick V
Published: May 2021

Previous studies proposed the use of antibody response to Porcine Reproductive and Respiratory Syndrome virus (PRRSV), measured as sample-to-positive (S/P) ratio, as a potential indicator trait to improve the reproductive performance of PRRSV-infected Landrace sows. However, this indicator trait has not yet been validated in Landrace sows or evaluated in a terminal sire line, such as Duroc. The main objective of this work was to perform host-genetic analyses of S/P ratio and reproductive traits during a PRRSV outbreak in maternal and terminal breeds. The data consisted of 690 Duroc and 541 Landrace multiparous sows (1.9±1.2 and 2.3±1.5, respectively) with S/P ratio collected at approximately 54 days after the predicted beginning of the outbreak. Of these, 644 Duroc and 528 Landrace sows also had reproductive data recorded during the PRRSV outbreak comprising number of piglets born alive (NBA), stillborn piglets (NSB), mummified piglets (NBM), number born dead (NBD; sum of NSB and NBM), total number born (TNB; sum of NBA and NBD), and number weaned (NW). All animals had genotype data on ~30K SNPs common across both breeds. Heritability estimates (± standard error) of S/P ratio during the PRRSV outbreak were moderate, with 0.33±0.06 for Duroc and 0.28±0.07 for Landrace. Reproductive traits during the PRRSV outbreak had overall low heritability estimates (≤0.18). Favorable genetic correlations of S/P ratio with NBA (0.65±0.33), in accordance with previous studies, and NBD (-0.33±0.28) were observed for Landrace sows only. Estimates of genetic correlation with other traits were -0.21±0.30 (NBM), -0.12±0.29 (NSB), 0.10±0.38 (NW), and 0.54±1.29 (TNB) for Landrace. For Duroc, these estimates were weaker: -0.33±0.40 (NBA), 0.26±0.27 (NBA), and 0.28±0.30 (NW), with convergence issues for mortality traits. These results further support the use of S/P ratio as an indicator trait for improved reproductive performance during a PRRSV outbreak in Landrace sows.
30 The Effect of Creep Feed Composition and Form on Pre- and Post-weaning Growth Performance of Pigs and the Utilization of Low-quality Nursery Diets
Authors: Christensen Brenda , Huber Lee-Anne
Published: May 2021

Fifty-six litters standardized to 12 piglets from first-parity sows were used to determine the effects of creep and nursery diet compositions on pre- and post-weaning pig growth performance. At three days of age, litters (initial BW 2.31±0.61kg) were assigned to one of four creep feeding regimens (n=14): [1] commercial creep feed (COM), [2] liquid milk replacer (LMR), [3] pelleted milk replacer (PMR), or [4] no creep feed (NO); creep feeds contained 1.0% brilliant blue as a fecal marker. Fecal swabs were collected every 3±1 days to identify piglets that regularly consumed creep feed. At weaning (18±1 days of age), six pigs per litter that consumed creep feed were placed on either a HIGH- (contained highly digestible animal proteins) or LOW- (contained corn and soybean meal as the main protein sources) quality nursery diet (n = 7) in a three-phase feeding program over 38 days.

The LMR disappeared at the greatest rate (37.7 g/pig/d; DM-basis) versus COM and PMR (10.8±1.5 g/pig/d; P < 0.001). Litters that received LMR had the greatest proportion of pigs with blue fecal swabs between study days 4 and 15 (85.0 vs 59.0±0.4%; P < 0.05) and LMR piglets had greater BW at weaning versus all other treatments (6.32, 6.02, 5.92, 5.67±0.14 kg, for LMR, COM, NO, and PMR, respectively; P < 0.001). Over the entire nursery period, pigs that received LOW diets had reduced ADG (399 vs 485±42 g; P < 0.001), ADFI (520 vs 595±37 g; P< 0.001), G:F (0.77 vs 0.82±0.03; P < 0.01), and BW at the end of the nursery period (21.2 vs 24.4±1.6 kg; P < 0.001), with no carryover effects of creep feeding regimen. Providing supplemental nutrition during the suckling period via LMR improved pig body weight at weaning, but did not improve post-weaning growth performance, regardless of nursery diet quality.
25 Estimating Fetal Age Using Transabdominal Ultrasonic Measurements in Sheep Early in Gestation
Authors: Navarrete Julissa , Kibler Michelle , Earing Jennifer , Lugar Drew W
Published: May 2021

An increasingly common method to detect pregnancy in sheep is transabdominal ultrasonography. Research has shown that transabdominal ultrasonography can be accurately measured between days 33–60 of gestation. Additionally, few studies have investigated the use of ultrasonic measurements as predictors of fetal age via transabdominal ultrasound. A pilot study found that pregnancy detection can be performed as early as 31 days with an accuracy of 100% and reported that embryonic vesicle depth (EVD) could be utilized to estimate fetal age. The purpose of the present study was to further evaluate the ability of transabdominal ultrasonography measurements to predict fetal age. Estrus was synchronized in fifteen crossbred ewes, followed by natural mating over a 24h period. From weeks 3 to 9 of gestation, transabdominal ultrasonography (at 3.5 MHz) was performed twice weekly. During on farm ultrasonography, pregnancy diagnosis and fetal count were recorded, and ultrasonic images were recorded for subsequent measurement of EVD and embryonic vesicle length. Eleven out of 15 ewes were confirmed pregnant from our sample. Using the surveyreg procedure in SAS we predict day of gestation through the independent variables: average embryo vesicle depth (aveEVD), aveEVD2, average embryo vesicle length (aveEVL), and the number of fetuses. The model predicts 82% of the variation in gestational age can be explained by the independent variables. Parameter estimates for aveEVD (P < 0.0001) and aveEVL (P < 0.0286) are positive, indicating that every 1 cm increase in these measurements results in 8.9 and 1.3 day increases in gestational age, respectively. Holding other factors constant, we find embryonic vesicle depth increases at a decreasing rate (aveEVD2, P < 0.001). These results indicate gestational age can be predicted through two embryonic vesicle measurements using transabdominal ultrasonography.
21 Effect of Corn Silage Inclusion Rate on Live Growth Performance, Carcass Characteristics, Net Energy Utilization and Beef Production Per Hectare in Feedlot Finishing Steers
Authors: Buckhaus Elizabeth M , Smith Zachary K
Published: May 2021

Maine-Anjou × Angus beef steers (n = 156; initial BW 366 ± 37.2 kg) were used in a finishing experiment at the Ruminant Nutrition Center in Brookings, SD. Steers were weighed on 2 consecutive days and assigned into 5 weight blocks (replicate pens). Treatments were arranged in a 2 × 2 factorial, 2 types of implants and 2 dietary treatments. Dietary treatments consisted (DM basis) of 1) 15% (CS15) or 2) 30% corn silage (CS30). Other ingredients consisted of DRC, HMC, liquid supplement and a dry supplement. The NEm, NEg and CP of CS15 was 94.8 Mcal/45.4 kg, 64.0 Mcal/45.4 kg and 12.7% and 91.2 Mcal/45.4 kg, 61.1 Mcal/45.4 kg, and 12.5% respectively (DM basis) for CS30. Bunks were managed using a slick bunk approach and all diets contained (DM basis) 33 mg/kg monensin sodium. Corn silage yield was assumed to be 45.7 Mg/ha and corn grain yield was calculated to be 10.2 Mg/ha. Beef production per hectare was calculated as (carcass adjusted final BW – initial BW)/hectare. No interaction between diet and implant (P ≥ 0.16) was detected for any variables. Final BW, ADG, and G:F were increased (P ≤ 0.02) by 2.2%, 6.5% and 7.2% respectively for CS15. Observed NE and the ratio of observed-to-expected NE for maintenance and gain was not influenced (P ≥ 0.15) by treatment. Dressing percent (64.52 vs. 63.47 ± 0.250; P = 0.01) and HCW (379 vs. 371 ± 13.1 kg; P = 0.02) were greater in CS15. Beef production per hectare was not impacted (P = 0.76) by feeding greater levels of corn silage. Feeding CS15 resulted in greater carcass-adjusted growth performance and HCW. No differences in beef produced per hectare of crop land means producers can feed greater inclusions of corn silage to finishing cattle without impacting carcass quality or beef production.
119 Lysine Requirement of Market Gilts Immunized Against Gonadotropin-releasing Factor on Performance and Carcass Composition
Authors: Vonnahme Kimberly A , Amodie Deb , Patience John , Pollmann Steve , Galina-Pantoja Lucina , Mellencamp Marnie
Published: May 2021

The objectives were to determine if the augmented growth performance of gilts administered anti-gonadotropin-releasing factor (GnRF) would require additional lysine and if anti-GnRF-treated gilts would require additional lysine to enhance carcass characteristics. The study treatments were arranged as a 2×3 factorial: control vs anti-GnRF (day 7 and 84; day 0 = 11 wk of age) and lysine at 100, 110, or 120% of requirement of the control gilts. Pen (n = 60) was the experimental unit (10 pens per treatment with 18 or 19 pigs per pen). There was no lysine × anti-GnRF interactions (P ≥ 0.2). Immunized gilts grew 3.7% faster and consumed 3.9% more feed with similar gain:feed from day 0 to market with increases occurring after the administration of the 2nd anti-GnRF dose. Immunized gilts weighed 3.4-kg more at marketing. The timing of marketing (4- or 6-week post 2nd dose) influenced the effects of anti-GnRF. Hot carcass weight, loin depth, and belly weight and thickness in anti-GnRF treated gilts were similar to control gilts at 4-weeks post 2nd dose but were greater in anti-GnRF vs. control (P ≤ 0.05) when harvested 6-weeks post 2nd dose. Backfat was greater, and lean was less, in immunized gilts vs. controls regardless of time to harvest. In conclusion, gilts immunized against GnRF had heavier carcass weights and required no additional lysine compared to controls.
118 Increased Growth and Carcass Attributes in Improvest®-treated Gilts Do Not Require Additional Dietary Lysine
Authors: Vonnahme Kimberly A , Van De Weyer Leanne , Amodie Deb , Patience John , Pollmann Steve , Galina-Pantoja Lucina , Mellencamp Marnie
Published: May 2021

Numerous studies have shown that gilts treated with Improvest® have greater carcass weights and increased ADG compared with untreated gilts. To develop the optimum nutritional program for Improvest-treated gilts, a randomized 5×2 factorial design of dietary lysine levels (90, 100, 110, 120, and 130% of NRC recommendations) with or without Improvest was performed. Gilts were housed in 120 pens (4 pigs/pen) at 8 weeks of age (day 0). Gilts and feed were weighed immediately prior to each dietary phase change (days 0, 21, 42, 70, 91, and 105). Improvest was administered at 9 and 19 weeks of age (4 weeks pre-harvest). There was no diet × treatment × day (P > 0.78) nor diet × treatment (P > 0.11) interactions for any variables. Gilts had similar BWT, ADG, and ADFI until after the 2nd dose of Improvest, when Improvest-treated gilts were heavier (123.62 vs. 121.59 ± 0.68 and 138.16 vs. 133.97 ± 0.71 kg, days 91 and 105; P < 0.01), had increased ADG (1.19 vs. 1.09 ± 0.01 and 1.03 vs. 0.88 ± 0.02 kg/day days 91 and 105; P < 0.01) and consumed more feed (2.99 vs. 2.84 ± 0.03 and 3.19 vs. 2.68 ± 0.04 kg/pig/day; days 91 and 105; P < 0.01) compared with untreated gilts. Carcass evaluation was conducted on 120 pigs (2 pigs/60 pens). No significant structures were present on ovaries of Improvest-treated gilts. Improvest-treated gilts were heavier (market and HCW; P ≤ 0.02) than controls. Improvest-treated gilts tended (P ≤ 0.08) to have heavier bone-in butt and bone-in ham weights. Belly weights were heavier (kg and %HCW; P ≤ 0.05) in Improvest-treated vs control gilts and were thicker (P = 0.01) but were similar (P > 0.3) in length and width. While IV was similar (P > 0.2) in belly fat, loin intramuscular fat was increased (P < 0.01) from Improvest-treated gilts. Without additional dietary amino acids, Improvest-treated gilts delivered greater gain after the 2nd dose, yielding significantly heavier carcasses and primal cuts, including bellies which were larger as a percentage of HCW, and increased loin intramuscular fat.
58 The Effect of Altering Dietary Manganese and Selenium Levels on the Growth Performance and Blood Manganese-superoxide Dismutase Activity in Nursery Pigs
Authors: Edmunds Clint E , Seidel Darren S , Welch Christina B , Lee Eliza A , Azain Michael J , Callaway Todd R , Dove C Robert
Published: May 2021

The objective of this study was to determine the effect of altering dietary levels of manganese and selenium on growth performance and MnSOD specific activity. Weaned piglets were blocked by weight (n = 216; 5.21 ± 1.17 kg; 21 ± 3 d) and sex (2 barrows and 2 gilts/pen). Pens within a block were randomly assigned to dietary treatments in a factorial design with main effects of Se (0.1 and 0.3 ppm) and Mn (0, 12, and 24 ppm). Diets (n = 9 pens/treatment) were fed in three phases (P1 = d 1–7, P2 = d 7–21, P3 = d 21–35). Pigs and orts were weighed weekly and pigs were bled on d 0, 7, 21, and 35 for analysis of specific activity of red blood cell MnSOD. Data were analyzed as 2x3 factorial design via SAS PROC GLM. There were no Se effects or Mn x Se interactions observed. There was a linear increase (P < 0.05) in overall ADG (397, 424, and 438 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). There was a linear trend (P < 0.1) in overall ADFI (557, 560, 592 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). Feed efficiency (d 0–35) across increasing Mn levels were 0.71, 0.76, 0.74 (P > 0.1). MnSOD activity in RBC increased from d 0–7, peaked on d 7 and decreased to d 35. On d 7, diets with 12 and 0 ppm Mn had significantly increased (P < 0.05) MnSOD activity (0.91 and 0.87 IU mg-1 protein, respectively) compared to diets with 24 ppm Mn (0.67 IU mg-1 protein). The dietary treatment that best maintained MnSOD activity was 0.3 ppm Se and 12 ppm Mn supplemented, while ADG was maximized in the diet with 0.3 ppm Se and 24 ppm Mn supplementation.
59 The Ash in Metacarpals, Metatarsals, and Tibia Is Better Correlated with Total Body Bone Ash Than the Ash in Other Bones of Growing Pigs
Authors: Lee Su A , Bedford Mike R , Stein Hans H
Published: May 2021

The objective was to determine correlations between individual and total body bone ash to identify the bone that is most representative of total body bone ash. Ten gilts and 10 barrows (BW: 40.8 kg) were allotted to 2 diets. The 2 diets were formulated to contain 60% or 100% of the requirement for standardized total tract digestible (STTD) P and STTD Ca with a STTD Ca:STTD P of 1.90:1, which is believed to maximize bone ash. Body weight and the amount of feed consumed by pigs were recorded on d 14 and 28 and carcass characteristics of all pigs were determined on d 28. Metacarpals, metatarsals, femur, tibia, fibula, ribs, and all other bones from the carcass were collected separately, defatted, and ashed. The statistical model included diet as fixed effect and sex and BW within sex as random effects. Correlation coefficients between total and individual bones were determined. Overall, pigs fed the diet formulated to meet 100% of the requirement for Ca and P had greater (P < 0.05) average daily gain and gain:feed compared with pigs fed the diet with 60% Ca and P, but there was no difference in average daily feed intake (Table 1). There was no effect of dietary Ca and P on carcass characteristics of pigs. Weights of bone ash were greater (P < 0.05) for pigs fed the diet with 100% rather than 60% of the requirement for Ca and P. Correlation coefficients between the weight of total bone ash and the weight of ashed metacarpals, metatarsals, and tibia were greater than 0.950 (P < 0.05), whereas correlation coefficient for femur, fibula, and ribs were less than 0.929 (P < 0.05). In conclusion, metacarpals, metatarsals, and tibia were more representative of total body bone ash compared with femur, fibula, and ribs.
94 The Effects of Dietary Crude Protein, Acidifier, and Pharmacological Levels of Zinc on Growth Performance of Nursery Pigs
Authors: Hutchens Wade M , Tokach Mike D , Woodworth Jason C , DeRouchey Joel M , Goodband Robert D , Dritz Steve S , Calderon Hilda I
Published: May 2021

Weanling pigs (n = 360, DNA 200 × 400, initially 5.90 kg) were used to evaluate pharmacological levels of Zn (ZnO), diet acidification (sodium diformate; Addcon, Bitterfeld-Wolfen, Germany), and crude protein (18 or 21% CP) on pig performance. At weaning, pigs were assigned to treatments with 5 pigs/pen and 9 pens/treatment. Treatments were arranged in a 2×2×2 factorial with main effects of Zn (110 mg/kg from d 0 to 21 or 3,000 mg/kg from d 0 to 7, and 2,000 mg/kg from d 7 to 21), diet acidification (without or with 1.2% sodium diformate), and dietary CP (21 or 18%). The 21% CP diets were formulated to 1.40 and 1.35% SID Lys in phase 1 and 2, respectively, and 18% CP diets were formulated to 1.20% SID Lys. Experimental diets were fed from d 0 to 21 with a common diet from d 21 to 42. Fecal samples were collected weekly to determine fecal dry matter (DM). Data were analyzed using R Studio as a RCBD. From d 0 to 21, ADG and G:F increased (P < 0.05) for pigs fed pharmacological Zn, and sodium diformate. Overall, ADG tended (P ≤ 0.069) to increase for pigs fed added Zn or sodium diformate. Pigs fed 21% CP had increased (P < 0.05) ADG and G:F from d 0 to 21 and overall G:F compared with those fed 18% CP. Feeding 18% CP diets increased fecal dry matter on d 7 when pharmacological Zn and sodium diformate were not in the diet (Zn×acidifier×CP interaction, P < 0.05). From d 21 to 42, there was no evidence of difference in growth performance. In conclusion, reducing CP without acidification increased fecal DM when pharmacological Zn were not in the diet, but had little effect when it was in the diet. Adding sodium diformate and pharmacological Zn independently improved nursery pig growth performance.
95 Growth Performance, Bone Mineralization, and Nutrient Digestibility of Nursery-grower Pigs Fed Phytase-supplemented Calcium and Phosphorus-deficient Diets
Authors: Lee Jung Wook , Chevalier Tyler , Sparks Chris , Crenshaw Tom D , Lindemann Merlin D
Published: May 2021

A 36-d experiment evaluated effects of supplemental OptiPhos Plus phytase (Huvepharma, Peachtree City, GA) on growth, bone mineralization, Ca and P digestibility of nursery-grower pigs. Individually housed crossbred pigs (n = 42; initial body weight [BW], 16.1 ± 0.4 kg) were randomly allotted to 7 dietary treatments based on BW and sex. A positive control (PC) diet was formulated to contain 0.601% Ca and 0.296% standardized total tract digestible (STTD) P, which were marginally lower than NRC (2012) requirement estimates for 25–50 kg pigs. A negative control (NC) diet (0.431% Ca and 0.164% STTD P) was developed by the removal of dicalcium phosphate from the PC diet and replacement with limestone and sand. Diets were: 1) PC, 2) NC, and 3–7) NC + 250, 500, 750, 1,000 and 1,500 FTU phytase/kg diet. On d 36, all pigs were euthanized for femur and metacarpal measures. Compared with NC, pigs fed the PC diet provided greater (P < 0.05) response for ADG (966 vs. 730 g/d), ADFI (1,660 vs. 1,329 g/d); bone measures (37.1 vs. 17.4 g ash/femur and 71.9 vs. 29.3 kg for metacarpal strength), and apparent total tract digestibility (ATTD) of Ca (69.5 vs. 63.5%) and P (62.5 vs. 49.3%). As supplemental phytase increased from 0 to 1,500 FTU/kg of diet, linear and quadratic increases (P < 0.002) occurred in overall ADG and ADFI, femur mineral content, metacarpal breaking strength, and ATTD of Ca and P. Responses statistically similar to PC were achieved at 250 or 500 FTU/kg and peak responses occurred at 750 to 1,500 FTU/kg that were numerically greater than PC for all but metacarpal strength. In conclusion, supplemental OptiPhos Plus improved growth, bone mineralization, Ca and P digestibility of pigs fed Ca and P-deficient diets, demonstrating enhanced Ca and P utilization of corn-soybean meal-based diets by nursery-grower pigs.
124 Effects of Different Feeding Levels Prior to Farrowing on Sow and Litter Performance
Authors: Harper Heath , Silva Gustavo , Peterson Beau A , Hanson Andrea , Hamilton Dan N , Vier Carine M , Soto Jose A , Lu Ning , Orlando Uislei A D A D
Published: May 2021

Our objective was to determine the effects of different pre-farrow feeding levels on sow and litter performance. On d 112 of gestation, a total of 309 sows (Camborough; PIC, Hendersonville, TN) were blocked by parity (P1, P2, P3+) and body weight and allotted to one of three treatments in a randomized complete block design. Treatments consisted of different feeding levels, which included: 1) 1.81 kg/d; 2) 2.72 kg/d; and 3) ad libitum access to feed. Sows were fed a corn-soybean meal-dried distillers grains with solubles-based lactation diet containing 3.36 Mcal of ME/kg and 1.17% SID Lys. Sows were weighed and visual BCS and caliper units were recorded at entry into the farrowing room at d 112 of gestation and at weaning. Daily feed intake was recorded from the beginning of the study until weaning. Litters were cross-fostered within treatment within 24-h after farrowing, and litter weights were collected at 12-h post-farrow and at weaning. Data were analyzed using the GLIMMIX procedure of SAS with sow as the experimental unit and block as a random effect. Covariates were used if they significantly improved the model fit. Ad libitum sows had the greatest (P < 0.05) feed intake from d 112 to farrow, followed by 2.72 kg/d and 1.81 kg/d treatments; however, no evidence (P > 0.10) for differences in lactation feed intake were observed. Wean-to-estrus interval was greater (P < 0.05) for ad libitum sows compared to sows fed 1.81 kg/d. Removal plus mortality rate was marginally lower (P < 0.10) for sows fed 2.72 kg/d compared to sows fed 1.81 kg/d. No evidence (P > 0.10) for treatment differences were observed in total born, stillbirth rate, and litter or piglet weight gain during lactation. In conclusion, results from this study do not support increasing feeding levels for sows prior to farrowing starting on d 112 of gestation.
167 Effects of L-lys Hcl and Distillers Dried Grains Inclusion Rate on Growth Performance of Finishing Pigs
Authors: Cemin Henrique S , Swalla Luke A , Pietig Jamie L , Hansen Sharlie A , Hansen Ernie L
Published: May 2021

An experiment was conducted to determine the effects of L-Lys HCl inclusion in diets with or without distillers dried grains with solubles (DDGS) on growth performance of finishing pigs. A total of 2,414 pigs (initial BW = 92.7 kg) were used in a 34-d trial. Treatments were arranged as a 2 × 3 factorial treatment structure with two levels of DDGS (0 or 10%) and three levels of L-Lys HCl (0.2, 0.3, or 0.4%). Diets were corn and soybean meal-based and were formulated to be isocaloric (NE = 2,668 kcal/kg) and isolysinic (0.75% SID Lys) by adjusting the inclusion of soybean meal, crystalline amino acids, and choice white grease. All other nutrient levels met or exceeded the NRC (2012) requirement estimates. There were 16 replicates per treatment. Pigs were weighed and feed disappearance measured to calculate ADG, ADFI, and G:F. Data was analyzed with SAS MIXED procedure. There was no evidence (P > 0.10) for interactive effects between L-Lys HCl and DDGS inclusion rate. Pigs fed diets with 10% DDGS had improved (P = 0.002) G:F, but there was no evidence (P > 0.10) for differences in ADG or ADFI. Pigs fed increasing levels of L-Lys HCl had higher (linear, P = 0.026) ADFI, decreased (quadratic, P = 0.013) G:F, and a tendency for quadratic response (P = 0.063) in ADG, overall with the poorest performance observed for pigs fed the diet with 0.4% L-Lys HCl. In conclusion, pigs fed 0 or 10% DDGS presented similar performance; however, pigs fed the high level of L-Lys HCl presented decreased performance.
166 Optimal tryptophan:lysine Ratio for 25–40 Kg Growing Pigs Fed Diets Containing 35 % Distillers Dried Grains with Solubles
Authors: Sespere Faria Oliveira Maryane S , Htoo John K , González-Vega J Caroline , Stein Hans H
Published: May 2021

Distillers dried grains with solubles (DDGS) has a high concentration of Leu, and the Trp requirement for growing pigs may be increased if diets contain excess Leu. Therefore, the objective of this experiment was to determine the optimum standardized ileal digestible (SID) Trp:Lys ratio in growing pigs fed diets with excess Leu from DDGS. A diet based on corn, soybean-meal, and 35% DDGS was formulated to be deficient in Trp and Lys, according to NRC requirements (0.13% SID Trp; 0.88% SID Lys; 15% SID Trp:Lys ratio). Four diets were prepared by adding L-Trp to the basal diet, which resulted in analyzed SID Trp:Lys ratios of 18, 20, 23, and 24% in these diets. One-hundred and twenty growing pigs (26.3 ± 2.0 kg) were allotted to one of the 5 dietary treatments with 3 pigs per pen and 8 pen replicates in a completely randomized design. Diets were fed for 21d and blood samples were collected on d-21. Data were analyzed by linear and quadratic contrasts in SAS. The optimal SID Trp:Lys ratio was estimated using linear broken-line (LBL) and quadratic broken-line (QBL) regressions for ADG and G:F, using NLIN procedure in SAS. Results indicated that average daily feed intake, ADG, G:F, and final body weight increased (linear and quadratic, P < 0.01) and plasma-urea-nitrogen decreased (linear and quadratic, P < 0.05) as dietary SID Trp:Lys increased (Table 1). The SID Trp:Lys ratio to optimize ADG was 20.9 and 23.4% by LBL and QBL, respectively. The G:F was optimized at 18.7 and 20.2% by LBL and QBL, respectively. The average SID Trp:Lys ratio for the 4 measurements was 20.8% which is greater than the current NRC requirement (SID 17.3%). In conclusion, diets formulated with 35% DDGS may need more dietary Trp than current NRC values.
164 Effect of Supplemental Dl-met Above Requirement on Performance and Serum Concentration of Amino Acids in Heat Stressed Pigs
Authors: Trejo Adriana Morales , Sánchez Verónica , Pérez Bayron , Camacho Lucero R , González-Vega J Caroline , Htoo John K , Cervantes Miguel
Published: May 2021

The intestinal morphology can be compromised in pigs when exposed to heat stress (HS), partly due to increased production of reactive-oxygen species. Because methionine (Met) functions as intracellular antioxidant, requirement of Met may be increased in HS-pigs. The effect of dietary supplementation with DL-Met above requirement on performance and serum concentration (SC) of free AA in HS-pigs was evaluated. A basal wheat-soybean meal diet was formulated to meet 100% Met requirement with the other indispensable AA exceeding at least 20% their requirement. Sixty individually housed pigs (23.0 ± 2.4 kg BW, 12 pigs/treatment) were randomly assigned to 5 treatments: TN100, thermal-neutral (22.7 °C) housed pigs fed the basal diet; HS100, HS120, HS140, HS160; HS pigs (29.6 to 39.4°C) fed the basal diet supplemented with DL-Met to contain 0, 20, 40, and 60% DL-Met above the requirement, respectively. Pigs had free access to feed and water during the 21-d trial. Blood samples were collected on d18 to analyze the absorptive AA-SC. The effect of ambient temperature (HS100 vs. TN100), as well as the linear and quadratic effects of increasing Met levels in the diets for HS pigs were analyzed. The performance results for the TN100, HS100, HS120, HS140, HS160 pigs were: Average daily gain (ADG), 728, 612, 720, 716, 719 g/d; average daily feed intake, 1.40, 1.34, 1.30, 1.30, 1.29 kg/d; gain:feed, 0.522, 0.474, 0.569, 0.563, 0.562, respectively. The ADG reduced (P < 0.01) in HS100 compared with TN100 pigs, but linearly increased in HS-pigs, besides gain:feed (P ≤ 0.05), in response to DL-Met supplementation. The SC of Ile, Leu, Lys, Phe, and Val were higher in HS100 pigs than in TN100 pigs (P < 0.05). Graded supplemental DL-Met in diets for HS-pigs linearly decreased SC of Ile, Leu, and Val (P < 0.05), tended to decrease His, Lys, and Thr (P < 0.10), and increased Met (P < 0.01). In conclusion, HS had negative effect on weight gain; however, it was ameliorated by adding 20% Met above the requirement.
204 An Investigation into the Role of Dietary Essential Fatty Acids Ratios and Linoleic Acid Level on Growth Performance and Inflammation of Grow-finish Pigs
Authors: Becker Spenser , Greiner Laura L
Published: May 2021

The objective was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (n6:n3) on the growth performance and inflammatory status of grow-finish pigs. A total of 300 growing pigs (BW = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) linoleic acid level with a high (20:1; HR), moderate (12:1; MR) or low (4:1; LR) n6:n3 in a 2 x 3 factorial design. Diets were fed across three 28-day phases and were balanced for dietary metabolizable energy. Pigs were housed 5 pigs per pen. Blood samples were collected on weeks 1, 3, 6, and 12, and synovial fluid was collected from the hock joint on weeks 1 and 12 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial body weight as a covariate, pen as the experimental unit, and linoleic acid level, ratio, and their interaction as fixed effects. Compared to HLA, LLA pigs had increased BW (P < 0.05) at d56 (103.2 vs. 101.3kg) and tended to have increased BW at d84 (P < 0.10; 129.1 vs. 127.8kg). Pigs receiving LR tended to have higher d84 BW compared to MR (P < 0.10; 129.1 vs. 127.3kg). There was no effect of linoleic acid ratio interaction for growth performance. In phase 2, pigs receiving LR had higher feed intake (P < 0.05) compared to MR. Pigs receiving HR performed intermediate of LR and MR. Overall, C-reactive protein was reduced in the plasma of pigs receiving HLA (P < 0.05; 19.3 vs. 26.2mg/mL). Across all treatments, CRP was reduced in synovial fluid and plasma in week 12 vs. week 1 (P < 0.05). In conclusion, LLA and a low ratio of n6:n3 improved final pig BW, and HLA is potentially beneficial in improving inflammation.
206 An Investigation into the Role of Dietary Essential Fatty Acids Ratios and Energy Level on Growth Performance, Inflammation, and Joint Health of Grow-finish Pigs
Authors: Becker Spenser , Greiner Laura L
Published: May 2021

The objective of this study was to investigate the effects of dietary metabolizable energy level and the ratio of linoleic acid:linolenic acid (n6:n3) on the growth performance and inflammatory status of grow-finish pigs. A total of 240 growing pigs (BW = 41.5 ± 6.1 kg) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) energy dietary treatment with a high (23:1) or low (12:1) n6:n3 in a 2 x 2 factorial design (n = 16). Diets were fed across three 28-day phases and were balanced for linoleic acid inclusion. Pigs were housed 4 pigs per pen. Blood samples were collected on weeks 1, 3, 6, and 12 of the study. Synovial fluid was collected from the hock joint on weeks 1 and 12 for inflammatory marker analysis. The pen was the experimental unit and data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with energy, ratio, and the interaction as fixed effects. Compared to LE, pigs receiving HE had increased BW (P < 0.05) at d28 (73.0 vs. 69.9kg), d56 (105.0 vs. 100.7kg), and d84 (135.3 vs. 129.9kg). For the overall period, HE had increased ADG compared to LE (1.10 vs. 1.06kg; P < 0.05) and improved G:F (0.41 vs. 0.37; P < 0.05), while LE increased ADFI compared to HE (2.88 vs. 2.72kg; P < 0.05). There was no effect of ratio or energy ratio interaction for growth performance. C-reactive protein tended to be reduced in hock synovial fluid of pigs receiving LE (1854.3 vs. 2277.3ng/mL; P < 0.10). Across all treatments, CRP was reduced in the synovial fluid and plasma in week 12 compared to week 1 (P < 0.05). In conclusion, dietary n6:n3 ratio did not impact growth performance or CRP response regardless of energy level.
203 Effect of a Supplemental Water Source on Performance of Growing-finishing Pigs
Authors: Hammers Kelsey , Jasper Jessica , Kern Simon , Boerboom Mike J , Johnston Lee , Knott Jeff S
Published: May 2021

Crossbred pigs (Fast Genetics 276 × PIC 800; n = 2,332; initial BW = 24.5 ± 1.6 kg) were used in two, 84-d growth trials to evaluate effects of an additional water source (fixed double nipple waterer) to a wet/dry feeder on growing-finishing pig performance. Pigs were assigned randomly to 1 of 2 treatments with 27 to 30 pigs per pen and 40 pens per treatment. Pens were equipped with a wet/dry feeder (SDI, drop shelf wet/dry feeder) or with a wet/dry feeder in combination with the additional water source. Marketing began on d 84 of each trial so the highest pig demands on feeders and waterers were assumed to occur from d 0 to 84 when all pigs were present in each pen. Growth data were analyzed using the GLIMMIX procedure of SAS and removals, mortalities, and total removals were analyzed using a Chi-square test in SAS version 9.4 (SAS Institute Inc., Cary, NC). No significant interactions between trial and water treatment were observed, thus data were combined using water treatment as a fixed effect and trial as a random effect. No differences were observed for body weight on d 84, average market weight, or number of removals, mortalities, or total pigs removed (Table). Similarly, no evidence for differences in overall average daily gain, average daily feed intake, or gain efficiency were observed regardless of an additional water source. However, pigs given access to a supplemental water source displayed a numeric increase in water disappearance per pig compared to pigs in pens with only wet/dry feeders. In conclusion, addition of a fixed double nipple waterer to wet/dry feeders did not influence growth performance of growing-finishing pigs.
139 Does Feeding an Increased Level of Narasin (Skycis) Result in Improved Growth Performance and Mortality in a Commercial Wean-to-finish Swine Feeding Program?
Authors: Kellner Trey A , Ellingson Josh , Thomas Paul
Published: May 2021

The response to narasin (Skycis 100, Elanco, Greenfield, IN) to date has been documented in research facilities with a high degree of control and via pigs with no insults to health or feed intake. Furthermore, these studies are always conducted on a single subset of pigs and diets. However, in commercial conditions, the response to narasin must be consistent and defined over a wide range of health statuses, stocking densities, feed intakes, environments, and diet formulations. The objective of this experiment was to determine which inclusion level of narasin (13.6 or 18.1 g/ton) would provide the greatest response under commercial conditions. A total of 197,629 weaned barrows and gilts (6.0 ± 0.1 kg; PIC 337 sired, Hendersonville, TN) were placed in 73 2,400-head commercial wean-to-finish barns that were alternated to 1 of 2 treatments (13.6 or 18.1 g of narasin/ton) in a rolling allotment over an 18-month period. Pigs were on the experiment for an average of 163 ± 1.6 days (until harvest). Throughout the 18-month experimental period, diets (outside of the narasin inclusion) were allowed to change to maximize return over feed costs. Data were analyzed using Proc MIXED (SAS 9.4; Cary, NC) with treatment as the main effect and barn as the experimental unit. Compared to 13.6 g/ton, the increased level of narasin (18.1 g/ton) improved ADG (13.6 g/ton = 0.76 versus 18.1 g/ton = 0.78 kg/d; P = 0.035), gain:feed (13.6 g/ton = 0.389 versus 18.1 g/ton = 0.401; P = 0.042), and mortality from wean to harvest (13.6 g/ton = 7.2% versus 18.1 g/ton = 5.3%; P = 0.084). In summary, feeding an increased level of narasin (18.1 g/ton) during an ever-changing (diet formulation, environment, and health status) commercial experimental conditions resulted in greater growth performance and reduced mortality.