bluuebunny/crossref_metadata_2025 huggingface dataset:
53 Comparison of digestibility of forages in Jersey steers supplemented with a yeast fermentation product on a high and low quality forage diet
Authors: Garcia Anissa R , Boyd Jamie , Splan Rebecca
Published: July 2019

The objective of this study was to determine the effect on digestibility of forages using a daisy jar system with inoculum from steers supplemented with the yeast fermentation product Saccharomyces cerevisiae. Forages tested included ryegrass, wheat, orchard grass, alfalfa, and sorghum sudan hays. Samples were ground through a 1mm screen, placed in Ankom F57 bags, and run in triplicate to increase statistical significance. Two ruminally cannulated jersey steers were used in a switchback design. Animals were housed in a dry lot pen. The study consisted of 2 three-week periods, 2-week standardization followed by a 1-week test period. Diets offered for period 1 were steer A = 100% alfalfa hay w/o yeast product and steer B = 100% wheat hay w/o yeast product. Diets offered for period 2 were steer A =100% alfalfa hay +15g/h/d yeast product and steer B =100% wheat hay +15g/h/d yeast product. During the test week, rumen fluid contents were collected from each donor via rumen cannula approximately 4 h after feeding and taken to the lab to be composited. The samples were incubated for 0 h, 24 h, 48 h, 72 h, and 96 h. At the end of the incubation period bags were collected and cold shocked to stop microbial digestion. Samples were dried at 55oC and stored for later analysis. Model included trt (+/-yeast), forage, hr, and interactions forage*hr and forage*trt. No significant differences were observed (P = 0.38) on DM digestibility or NDF digestibility (P = 0.76) with the supplementation of yeast fermentation product. Forage*Trt was significant (P = 0.03 DMdig, P = 0.02 NDFdig). Implications of this study are the inclusion of a Saccharomyces cerevisiae fermentation product at a rate of 15g/h/d may not impact overall forage NDF or DM digestibility but may impact types of forage differently in an in vitro system using composited inoculum from donors on a forage diet.
3 Deep Frame-based tracking on nursery pigs
Authors: Schmidt Ty , Psota Eric , Mote Benny , Perez Lance , Mittek Mateus
Published: July 2019

Rapid identification of morbid/injured pigs is essential for swine producers to ensure the health and well-being of each individual pig and ensure production efficiency. As such, there is a need to develop advanced technology as a means to further ensure the health and well-being of pigs. The objective of this study was to evaluate a novel computer vision, Deep-Frame – Detection and Tracking Platform (DF–DTP), for the ability to automatically identify/maintain identity and continuously track the activities of group-housed pigs. Utilizing a depth-enabled camera and multi-ellipsoid expectation maximization technology, 28 nursery pigs were continuously evaluated during the first 42 d of the nursery phase. Over the 42-d nursery period, the DF–DTP was capable of achieving a 93.7% accuracy for identifying and maintaining the identity of individual pigs. Through visual validation (10,544 observations), 642 identification errors were detected. Of the identification errors, 82% occurred when pigs were lying, 7.8% standing, 2.1% walking, 7.2% at the feeder (at the feeder), and 1.0% at the waterer. The DF–DTP was capable of a 96.2% accuracy rate for classification of an individual pig’s activity. Accuracy for classification of activities was 96.3% for walking, 96.3 for standing, 99.1 for lying, 86.4% for at the feeder, and 73.6% for at the waterer. Across the 42-d trial, the average time pigs spent 77.8% (+ 0.02) lying, 8.6% (+ 0.32) standing, 2.9% (+ 0.09) walking and traveled 943.1 meters/d (+ 195.9). Over time (d 1 – d 42), the time pigs spent lying, standing, walking, and meters/d decreased (P 0.001). As d within the nursery phase increased, time at the feeder increased (P < 0.001), there was no change (P = 0.11) for time at the waterer. Results of the study indicate that the DF–DTP is capable of accurately identifying, maintaining the identity of and continuously tracking the activity of group-housed nursery pigs.
9 Behavioral and stress responses to feeding frequency in pregnant sows under isocaloric conditions
Authors: Manu Hayford , Lee S H , Huang Q , Pangeni D , Keyes M C , Cairns J , Baidoo S K
Published: July 2019

The objective of this study was to investigate behavioral and stress responses to feeding frequency in pregnant sows under isocaloric conditions. Eighteen sows (Landrace × Yorkshire); BW 226.10 ± 1.29 kg; parity 3.1 ± 0.42); were blocked by parity and randomly assigned to 1 of 3 feeding frequency regimes. Sows were fed corn-soybean meal-based diet 1× [0730 (Control, T1), 2× “[half ration at 0730 and 1530 h (T2)]” and then “[one-third portion at 0730, 1130, and 1530 h (T3)]”. On average, sows received 7190 kcal ME d−1 during gestation from 2.25 kg of diet formulated to contain SID Lys/ME of 1.71 g/Mcal. Saliva samples were collected from 0630 to 1830 h, 2 hrs apart and assayed for cortisol using ELISA technique. Behavior data were collected for 7 d from d 53 of gestation by affixing a Remote Insights ear tag to each sow. Each sow had 120,960 data points categorized into: “Active,” “Feed” or “Dormant”. The data were analyzed using GLIMMIX procedure of SAS 9.4 with treatment as fixed effect and sow as random effect. Results were considered statistically significant when P < 0·05 and were considered as trends when P ≤ 0·10. Sow was the experimental unit. A 24 h area under the curve (AUC) was calculated by trapezoidal method. The P-values were adjusted for multiplicity based on Tukey Kramer’s method. A 24 h total activity and total feeding activity AUC were reduced in sows fed 2× daily compared with sows fed 1× and 3× daily (P < 0.01). A 12 h cortisol AUC was lower for sows fed 2× daily relative to treatment groups fed 1× and 3× daily (P < 0.02). In conclusion, feeding pregnant sows twice daily may improve sow welfare by reducing feeding activity, total activity, and the activation of hypothalamic-pituitary-adrenal (HPA) axis.
10 A field study to investigate the effect of Zuprevo administered alone or in combination with banamine transdermal on the health and well-being of transported feedlot calves on arrival at the feedlot
Authors: Martin Miriam S , Kleinhenz Michael , Kleinhenz Katie , Reppert Emily , Blasi Dale , Parks Timothy , Baysinger Angela , Hutcheson John , Coetzee Johann
Published: July 2019

Long distance transportation can be a significant source of stress to cattle and is associated with increased risk of bovine respiratory disease (BRD). The administration of a nonsteroidal anti-inflammatory drug (NSAID) has been shown to reduce stress following long distance transport. The objective of this study was to compare production parameters, morbidity, and mortality between calves receiving either tildipirosin alone or in combination with transdermal flunixin on arrival at the feedlot. 384 head of polled, Continental x English and English crossbred bulls and steers were enrolled into one of two treatments: 1) tildipirosin only (PLBO) 2) tildipirosin in combination with transdermal flunixin (FTD). Tildipirosin was administered in the neck as a single dose of 4 mg/kg alone, or in combination with transdermal flunixin applied to the dorsal midline at the label dose of 3.3 mg/kg. Outcomes measured were performance parameters, dry mater intake and feed efficiency, morbidity and mortality, pen pulls and treatments, a daily visual analog scale (VAS) assessment and accelerometer data. Statistical analysis was performed using computer software (JMP 13, SAS Institute, Cary, NC). There were no significant differences in average lot weights between treatment groups (P = 0.415). There were no treatment effects on the determined dry matter intake (P = 0.51). There were no significant differences observed in morbidity and mortality between groups (P = 0.292). VAS pain assessment showed significant differences for time (P < 0.0001) and time by treatment interaction (P < 0.0001), with FTD calves having lower (VAS) scores. There were no significant differences between treatments for the acceleration data (P = 0.190). Calves administered transdermal flunixin had lower VAS scores indicating less pain the first 36 hours after drug application. Over the 63-d feeding period, no advantages in performance were observed following FTD administration.
16 Long-term immune and metabolic consequences of a disrupted early life microbiota
Authors: Willing Benjamin P
Published: July 2019

In the first weeks of life, the gastrointestinal tract changes dramatically in structure and function, including a rapid expansion and maturation of the immune cell population. Successful intestinal development comes at a significant energy cost yet is essential to subsequent performance and health. Many of the developmental changes in intestinal and immune development are dependent on the abundant and diverse population of microbes (microbiota) residing at the mucosal surface and in the intestinal lumen. We are now beginning to understand that the nature of the first exposures in the first days to weeks of life have a long-term impact on physiological processes important to metabolic health, as well as immune programming that impacts response to pathogen challenge. In this presentation I will discuss our key findings on the significant impacts early life microbial disruption have on intestinal, pancreatic, and immune function of the piglet. I will also discuss the consequences of excessive hygiene on disease resilience as well as the ability to mount a successful immune response in response to vaccination. Understanding the ability of the early life microbiota to program subsequent health provides a significant opportunity to support healthy pig production as we move away from antibiotic use in livestock production.
20 Nutritional strategies to manage gilt growth and optimize lifetime productivity
Authors: Lents Clay A , Supakorn China , Vallet Jeff , Dean Boyd R , DeDecker Ashley , Stalder Kenneth J
Published: July 2019

Improving gilt development is key to maximizing sow longevity. How to best manage and feed gilts during development is heavily debated. A series of studies were conducted to determine the optimal feeding program for gilts during development. The hypothesis was that metabolizable energy (ME) and standard ileal digestible lysine could be varied under commercial conditions (ad libitum feeding) to optimize body weight gain and composition, age at puberty, and mammary gland development to support increased productivity of gilts. Studies were conducted in commercial production facilities in Iowa and Utah using large numbers of maternal-line gilts that were monitored, under various dietary treatments from 100 to 200 d of age, for growth, body composition, age at puberty and development of reproductive organs and mammary glands. Varying the dietary Lysine:ME ratio (g:mcal) had modest effects on growth and body composition of gilts. Likewise, development of reproductive organs was minimally affected by diet, but slower growth delayed development of terminal lobular ductal units in mammary glands. Growth rates were slowed by reducing dietary lysine:ME ratio below the requirement and increasing fiber. Gilts still had adequate growth (> 600 g/d) and body composition (≥ 15 mm backfat) for good reproductive performance. Although dietary treatments did not affect the average age of puberty (205 d) or the total number of gilts that reached puberty, a greater percentage of gilts fed higher lysine diets exhibited puberty during the first 40 days of boar exposure. Gilts lost 2 to 3 mm backfat once moved from the development unit to the breeding farms, but pregnancy rates were ≥ 95%. Culling of gilts before first breeding did not vary with diet but was considerably higher than expected. Investigation of how these developmental traits affect productivity through subsequent parities is ongoing.
17 Effects of birth traits, physical or fenceline boar exposure and group size on pubertal measures and lifetime fertility of replacement gilts
Authors: Knox Robert V , Daniel Ashley , Patterson Jenny , Arend Lidia S , Foxcroft George
Published: July 2019

In experiment 1, prepubertal gilts with (n = 264) and without (n = 43) birth records received Fenceline (FBE) or Physical (PBE) Boar Exposure (BE) in a Boar Exposure Area (BEAR). At 185 d of age, gilts (13/pen) received BE for 15 min/d for 3 wk. At the start of Week 3, anestrual gilts received PG600 or no-PG600 (Control). At estrus, females were moved into stalls and inseminated at 2nd heat. Gilts born in larger litters were lighter (r = -0.26) while heavier pigs grew faster to puberty (r = 0.25). PBE increased estrus in Week 1 (38%) over FBE (28%). In Week 3, PBE-PG600 increased estrus (79.9%) compared with PBE- Control (36.2%), while FBE-PG600 and Control did not differ (52.7 vs. 42.5%). By 6 wk, estrus tended to be greater (P < 0.08) for PBE (91.2%) than FBE (83.2%). Reduced fertility associated with: 1) small birth litter; 2) heaviest birthweight; 3) slower growth rate; 4) delayed puberty and age at 1st service; and 5) abnormal estrus interval. Experiment 2 tested the pubertal response to PBE or FBE with 10 or 20 gilts/pen. Gilts (n = 180) at 168 d with 1.8 m2 floor space received BE once/d for 15 min for 1–3 wk. At the start of Week 3, anestrual gilts received PG600. Estrus in Week 1 (7.3%) did not differ, but a BE x Pen effect occurred in Week 2 (estrus range: 15–34%). In Week 3, PG600 increased estrus (P < 0.03) in Pens of 10 (83.7%) compared to Pens of 20 (64.1%). BE method had no effect and Pens of 10 had greater estrus (P = 0.05) than Pens of 20 (88.3 vs 75.8%). These results indicated that use of PBE, a BEAR, smaller group size, and PG600 can be used in combinations to enhance puberty induction. Birth and pubertal measures influenced service and farrowing rate, litter size, and age at removal.
23 Dietary management of the transition animal: Perspectives from dairy cows to sows
Authors: Saun Robert Van
Published: July 2019

Since the 1990s, the impact of late gestational nutrition and management on lactation and reproduction has become the focus of dairy management. Transition cow management has been credited with having greater influence on herd performance as compared to previous focus on lactation nutrition. Several seminal papers published in 1990s and early 2000s directed management practices of dry cows, rightly or wrongly, toward critical factors impacting calving and lactation. Dairy cow gestational protein requirements cited a 1956 study on Red Danish cows until Bell (1995) characterized the modern Holstein fetus’ chemical composition over the last 70 days of gestation. Recognized health effects of “fat cow syndrome”, similarly described for pigs, focuses late pregnant dairy cow management on body condition management starting in late lactation. Optimum condition was emphasized, recognizing negative impacts of excessive limited BC on lactation and reproduction. Maximizing dry matter intake was a nutritional goal for preventing energy-based metabolic challenges, until research indicated excessive energy during early, non-lactating period was more critical to managing postpartum metabolic derangements than the weeks prior to calving; which is like controlling energy intake of sows. Delivery of amino acids, estimated by metabolizable protein intake, has recently earned focus of research, relative to immune function, metabolic stability and reproductive success during early lactation. Identifying amino acids as critical fetal metabolic fuel, and consequences of excessive maternal protein mobilization, has become a focal point of swine and dairy transition nutrition. Although management of the transition cow has been greatly refined through nutritional research, improved cow performance has not yet been realized in the field. Recognition of the interplay between nutrition, environment and management relative to enhancing cow behavior has provided insight to the challenges of managing the transition cow. Metabolic, environmental and management challenges facing the physiologic transition from pregnancy into lactation occur in all production species. Although cows and sows procure essential nutrients by different digestive modes, cross-species applications can provide new or reinforcing perspectives on collective management approaches.
25 Evolution of the commercial sow
Authors: Rohrer Gary
Published: July 2019

Swine production has dramatically changed in the past 30 to 40 years. The small producer that raised pigs with minimal investment when the economics were desirable (“part-timers”) has been replaced by full-time swine producers with massive capital investments. As this revolution in production practices has occurred, the optimal animal has evolved. Today’s market hog is leaner and weighs 20% more, yet goes to market at a similar age and consumes a similar quantity of feed. While these changes are impressive, they are dwarfed by the changes in the modern commercial sow, which births 30% more piglets and has 10% more litters/year. Today’s commercial sow is a culmination of research efforts in reproductive physiology, nutrition, facility design and animal management synergistically combined with modern genetic selection theory. She is a first-generation cross between a Landrace and a Yorkshire/Large White parent from lines that have been selected for superior reproductive performance and lean tissue growth. Selection has emphasized prolificacy, milk production and return to estrus in a lean, fast growing animal. While her current performance figures are impressive, there is still room to improve. She will continue to evolve to fit future production needs and environments to supply the world with nutritious pork products.USDA is an equal opportunity provider and employer.
30 Mutli-omic data integration in quantitative genetics
Authors: Morota Gota
Published: July 2019

The advent of high-throughput technologies has generated diverse omic data including single-nucleotide polymorphisms, copy-number variation, gene expression, methylation, and metabolites. The next major challenge is how to integrate those multi-omic data for downstream analyses to enhance our biological insights. This emerging approach is known as multi-omic data integration, which is in contrast to studying each omic data type independently. I will discuss challenging issues in developing algorithms and methods for multi-omic data integration. The particular focus will be given to the potential for combining diverse types of FAANG data and the utility of multi-omic data integration in association analysis and phenotypic prediction.
29 Introduction to functional annotation of animal genomes consortium
Authors: Tuggle Christopher K , Giuffra Elisabetta
Published: July 2019

The annotation of the functional components of genomes is required for both basic and applied genomic research, yet farmed animal genomics are deficient in such annotation. This talk will introduce the Functional Annotation of ANimal Genomes (FAANG) consortium, which was initiated in 2014 to address this knowledge deficit. An overarching theme of early FAANG efforts is the collaborative approach required for such comprehensive research, thus another emphasis of this talk will be our community efforts to develop the environment for successful FAANG research. FAANG scientists have created a coordinated data collection and analysis enterprise crucial for success of this global effort, and funding of ~$20 million has been secured for current projects in several species, with an anticipated doubling of this support during 2019. Member FAANG consortium labs are producing genome-wide datasets on RNA expression, DNA methylation, chromatin modification, chromatin accessibility, and chromatin interactions for many agriculturally relevant animal species. The goal of a first-generation global chromatin state map for cattle, chicken, pig, and potentially other species is projected for completion in the next 3–5 years. These data will be used both to better understand animal genome function at the epigenetic level, as well as improve the precision and sensitivity of genomic selection for animal improvement. The functional annotation delivered by the FAANG initiative will add value and utility to the greatly improved genome sequences being established for domesticated animal species.
39 Management of cereal-grain forages for yield and quality
Authors: Coblentz Wayne K , Akins Matthew
Published: July 2019

Cereal-grains have a long history of providing quality forage for livestock operations. Our objective is to review the existing literature and describe the principle factors controlling the yield and quality of cereal-grain forages. Generally, cereal-grain forage production can occur via management scenarios that include: 1) winter-annuals planted during fall and then grazed or harvested the following spring; 2) cereals not requiring vernalization planted during early spring and harvested during late-spring or summer; and 3) cereals not requiring vernalization planted during late-summer and harvested before winter. Winter-annuals planted during fall also are used extensively for fall grazing, particularly for backgrounding stocker cattle. The requirement for vernalization before plants elongate and produce viable seed plays a large role in synchronizing management strategies with producer goals. For example, maximization of fall growth can be attained by choosing a species or cultivar that does not require vernalization and will elongate, but this choice will likely eliminate winter survival and subsequent spring forage production. Ambient temperature during plant maturation affects lignin formation positively; therefore, forages grown during cooler fall temperatures will typically exhibit greater NDF digestibility than those maturing during summer. Most nutritional characteristics are influenced heavily by two competing processes that include the normal negative maturation effects that reduce the quality of most forages. However, this process is juxtaposed against the physiological process of grain fill, which can dilute concentrations of forage fiber components, increase energy density, and improve DM digestibility at advanced plant-growth stages. Digestibility of NDF declines with plant maturity, and generally is not affected by grain fill. A boot-stage harvest for silage often exhibits the most favorable nutritional characteristics for lactating dairy cows; however, producers making this management choice will need to accept a substantial yield penalty compared with a commonly recommended harvest at soft-dough stage, which would likely maximize yield.
41 Management effects on long-term crop yield stability in central and eastern nebraska
Authors: Jin Virginia , Sindelar Aaron , Schmer Marty , Wienhold Brian
Published: July 2019

The sustainability and resilience of cropping systems will depend on how different management practices impact yield stability over the long-term. Here, we summarize the effects of crop rotation, tillage, crop residue removal, and nitrogen fertilizer rate on corn and soybean yield responses from several long-term research experiments maintained by the USDA-Agricultural Research Service in eastern and central Nebraska. Across all study sites, we found that yield stability is affected most by crop rotation, then tillage, then residue management, where stability can be further improved in all systems by using the optimum N fertilizer rate. While crop rotation and rotation complexity tend to have the greatest impact on long-term yield stability in the western Corn Belt, nearly all combinations of management can produce stable yields if well managed.
46 How far we could go reducing crude protein with the use of supplemental amino acids
Authors: Pomar Candido
Published: July 2019

Feeding growing pigs with diets providing the required amount of essential and non-essential amino acids (AA) reduces energy expenditure and minimizes N excretion. Low protein diets can be obtained by supplementing feeds with crystalline AA. Numerous experiments have evaluated the ideal dietary AA concentration at different growth stages, but reducing dietary protein with the use of supplemental AA is limited by the inaccuracy of the principles used to estimate AA requirements. One of these principles states that growing animals need AA for maintenance and growth. Maintenance requirements are related to BW whereas the efficiency of AA utilization (e.g., 72% for Lys) and body protein AA composition are constant (e.g., 7% for Lys). These parameters are, however, affected by AA restriction, meal frequency, energy supply, genetics, etc. Even when controlling these factors, individual pigs respond differently to the same AA supply. Yet pigs are raised in groups and fed with a unique feed for long periods. Individual pigs within a given population differ in terms of BW, ADG, health status, etc., and consequently, differ in the amount of AA they need at a given time. Therefore, when feeding a group of pigs, the concept of maintenance and growth requirements may not be appropriate. In this situation, nutrient requirements should be seen as the optimal balance between the proportion of animals that needs to be overfed and underfed. Given that for most AA, underfed animals exhibit reduced performance, whereas overfed animals exhibit near-optimal performance, optimal growth is obtained when nutrients are provided to satisfy the requirements of the most demanding animals. There is therefore a trade-off between performance and dietary protein reduction. The inaccuracy of the principles used to estimate AA requirements, both for individual animals and populations, limits how far we can go reducing dietary protein with the use of supplemental AA.
43 Commercial realities of amino acid nutrition in the young pig
Authors: Cook David A , Pilcher Chad , Humphrey Brooke
Published: July 2019

Applied amino acid nutrition continues to provide new and meaningful solutions to support advancements in animal performance, health and sustainability. While there continues to be focus on how amino acid nutrition can be optimized for performance, there remains to be opportunity to optimize applied nutrition for the young pig in order to support the weaning transition. As alternatives for antibiotics and heavy metals continue to be explored, their success will in large part depend upon the successful application of amino acid nutrition. There are several complicating factors related to applying amino acid nutrition in the young pig. First, intestinal function at weaning is compromised, resulting in reduced digestive and absorptive capacity. From an amino acid nutrition standpoint, this can lead to increased N flow into the hindgut where it can be fermented into inflammatory irritants, resulting in diarrhea and poor growth. Second, ideal protein models for digestive health are scarce and often approaches of limiting lysine inclusion as a percent of crude protein are used as an alternative. Third, the application of amino acid nutrition is based upon digestibility values obtained from older animals. Review of the literature indicates that these are in excess of what the young pig can digest, further impacting the N flow to the ileum and hindgut. As we continue to apply amino acid nutrition at the commercial level, we must look for solutions to address these items while more basic work can be done to obtain the needed information on digestibility and requirements.
50 Role of fatty acid nutrition in milk fat synthesis
Authors: Lock Adam L
Published: July 2019

Our understanding of fatty acid (FA) digestion and metabolism in dairy cows has advanced significantly in the last few decades. We now recognize that FA, both of dietary and rumen origin, can have different and specific effects on feed intake, rumen metabolism, small intestine digestibility, milk fat synthesis in the mammary gland, and energy partitioning between the mammary gland and other tissues. We will present research focusing on specific FA and how dairy cows respond differently to combinations of FA. Recent research has highlighted differences in intestinal digestibility among palmitic acid (C16:0), stearic acid (C18:0), and oleic (cis-9 C18:1) acids, which impacts the amount and profile of absorbed FA available for metabolic purposes including milk fat synthesis. C16:0, C18:0, and cis-9 C18:1 usually comprise the majority of FA present in milk fat and adipose tissue of dairy cows. In addition, these FA comprise the major FA in a wide range of commercially available fat supplements. While these FA have different functions in metabolism, they may also interact with each other by competitive or complementary mechanisms under different physiological conditions. In the mammary gland, milk FA are derived from 2 sources; 16 carbon FA originating from extraction from plasma. 16-carbon FA originate from either de novo or preformed sources. Milk lipid synthesis in the mammary gland is dependent upon the simultaneous supply of short/medium-chain FA and long-chain FA. C16:0 has a higher preference as a substrate to start triglyceride synthesis than C18:0 or cis-9 C18:1. Also, if the amount of preformed FA surpasses the capacity of the mammary gland, these might be redirected to other tissues (e.g. adipose tissue) altering energy partitioning. In the future, the opportunity and challenge will be to continue to improve our understanding of how and which FA affect nutrient digestion, energy partitioning, and milk synthesis in lactating dairy cows and effectively apply this knowledge in the feeding and management of high producing dairy cows.
51 Feedstuff fatty acid content, variation, techniques and implications on practical animal nutrition
Authors: Ocker Cliff
Published: July 2019

Fatty acid nutrition in ruminants, dairy cattle primarily, has increased as a point of emphasis with nutrition formulation in the past decade, as the diet fatty acid profile and metabolism has been found to impact milk fat concentration and animal health. Both the fatty acid supply and rumen degradation warrant further investigation in dairy diets for improved formulation strategies in the future. As supply and degradation are better understood, improved formulation approaches will be possible now that routine feed fatty acid measures have become more practical with the development of near-infrared reflectance spectroscopy (NIR) models at commercial feed analysis laboratories. NIR model development techniques vary; however, the general approach is to calibrate against a wide ranging database of feedstuff wet chemistry measures using a partial least squares approach. Models relate spectral observations (i.e. reflectance at a specific near-infrared light wavelength) to wet chemistry observations. NIR models should reflect both the mean and variation observed in the wet chemistry database. The NIR models developed by Rock River Laboratory, and resulting feed library database information presented in Table 1, were developed by calibrating against feedstuff chemistry performed at the Lock laboratory with Michigan State University. Wet chemistry fatty acid determination by analytical laboratories, using gas chromatography techniques against known fatty acid standards, deserves further discussion to agree upon peak identification schemes. Differences in peak identification from one laboratory to the another will result in different total fatty acid measures and NIR models. The fatty acid content and profile coefficients of variation, determined from the mean and standard deviations presented in Table 1, range from less than 10 to over 100% of the mean with an average CV of 27%. This suggests substantial variation is present in commercial feeds, and opportunities may exist to better account for variation and fatty acid supply in dairy diets.
53 Young Scholar Presentation: Diet starch concentration and starch fermentability affect energy intake and production of dairy cows during the postpartum period
Authors: Albornoz Rodrigo I , Allen Michael
Published: July 2019

Our objective was to evaluate the effects of starch concentration and starch fermentability of diets fed during the early postpartum (PP) period on DM and energy intake and production. Fifty-two multiparous Holstein cows were used in a completely randomized block design with a 2 X 2 factorial arrangement of treatments. Treatment diets were formulated to 22% (LS) or 28% (HS) starch with dry-ground corn (DGC) or high-moisture corn (HMC) as starch source. Treatments were fed from 1 to 23 d PP, and cows were switched to a common diet until 72 d PP to measure carryover (CO) effects. Throughout the experiment, DMI and MY were measured daily, and milk components and BW were measured weekly. During the TP, feeds, refusals, and fecal samples were collected and digestibility was determined weekly. During the TP, HMC decreased intakes of DM and net energy of lactation (NEL) more when included in the HS (3.9 kg/d and 3.2 Mcal/d) than in the LS (0.9 kg/d and 0.6 Mcal/d) diets and HMC decreased yields of milk, fat, protein, 3.5% FCM and milk NEL by 4.3, 0.19, 0.18, 4.8 kg/d and 2.8 Mcal/d, respectively. Energy balance was improved by HS compared with LS (-14.7 vs. -16.8 Mcal/d). During the CO period, treatment effects on DMI diminished over time with no main effects of treatment for the entire period. Treatments interacted to affect yields of milk, milk fat and FCM during the CO period, which were greater for HS-DGC and LS-HMC (54.8 and 52.8, 1.76 and 1.81, and 51.3 and 52.2 kg/d, respectively) than for LS-DGC and HS-HMC (51.2 and 51.0, 1.68 and 1.64, and 48.4 and 48.6 kg/d, respectively). Feeding a highly fermentable starch source during the early PP period decreased DM and energy intake and production, with treatment effects diminishing during the CO period.
Nutrition as a way to improve the dairy industry sustainability: a nutrigenomic approach
Authors: Riboni Mario Vailati , Roche John , Yoon Ilkyu , Loor Juan
Published: July 2019

Due to the high incidence of diseases and high culling rate, the peripartum is a period of significant stress, and its management sets the stage for the health, future productivity and reproductive performance of the herd, hence making it the perfect target to improve the industry sustainability as a whole. Looking at grazing systems, using a nutrigenomic approach, we determined that, contrary to historic industry standards, cows should be slightly underfed (~75% of their energy requirements) in the three weeks before parturition to prime their metabolism and ensure an optimal transition. Farmer will be able to preserve pasture area in a period of low forage production, reaching the spring (calving season) with abundant and high quality pasture. While looking at confined systems we tested the supplementation efficacy of immunomodulatory nutrients. The greater feed intake and greater milk production performances (both in milk quantity, and quality), coupled with lower incidence of disease, underscore a smoother transition to lactation when cows are supplemented with rumen-protected methionine. Moreover, methionine induced greater blood neutrophil phagocytosis and oxidative burst postpartum, and optimized the response to LPS, by mitigating the hyper-response of the immune cells. Supplementation of cows undergoing a mastitic challenge with a S. cerevisiae fermentation product improved indexes of mammary gland health and pathogen resistance. Pathway analysis highlighted physiological mechanisms enhancing local immune cell trafficking, antimicrobial activity, and inflammation control in the mammary gland of supplemented animals, compared to control cows that showed signs of tissue damage and loss of epithelial integrity. Looking at calf nutrition, enhancing nutrient intake in the pre-weaning period stimulates mammary development, increasing their future productivity potential. Nutritional improvement of animal health shows great potential as a rapidly applicable strategy to improve animal welfare, allowing them to express their full genetic potential.
57 Impact of weaning stress, disease, and diet on pig performance, intestinal function and integrity
Authors: Gabler Nicholas K , Helm Emma T , Mille Carson De
Published: July 2019

Inevitably, pigs will experience stressors that antagonize lean tissue accretion, appetite, and feed conversion. Depending on the production system and age of the pig, these stressors commonly include weaning transition, diet changes, vaccination, enteric and respiratory pathogen challenges, activation of the HPA axis, and social stress. Additionally, the morbidity and mortality that accompany these stressors may be exacerbated by the illegalization of sub-therapeutic antibiotic use for growth promotion (AGPs) by the Veterinary Feed Directive. However, morbidity and mortality may also be mitigated by diet ingredients via direct and indirect modes of action on gastrointestinal health and function. The gastrointestinal tract has the vital but conflicting functions of nutrient and water absorption, while simultaneously regulating host mucosal defenses against noxious luminal contents such as microorganisms and their toxins. This puts the gastrointestinal tract epithelium and splenic tissue at the front line of nutrition, growth, and health of the pig in the new age of antimicrobial resistance concerns. As part of the body’s splanchnic tissues, the gastrointestinal tract is very metabolically active and has high utilization of luminal nutrients and energy. This utilization or “first pass metabolism” by intestinal epithelial and lamina propria cells can be a major determinant of the systemic or post-absorptive availability of glucose, essential and non-essential amino acids, and short and long chain fatty acids. This makes the gastrointestinal tract critically important to the growth and health of livestock and avian species. This paper will discuss the physiological impact of various stress challenges and nutrition on pig performance, gastrointestinal function and integrity.
62 Improved estimation of indirect social genetic effects in group-housed pigs by quantifying behavioral interactions
Authors: Barajas Belcy Karine Angarita , Cantet Rodolfo , Wurtz Kaitlin E , O’Malley Carly , Siegford Janice , Ernst Catherine , Steibel Juan P
Published: July 2019

Traditional social genetic effects modeling assumes uniform intensity of interaction between group members. Tree breeders proposed relaxing this assumption by incorporating estimates of intensity of competition between pairs of individuals. Here, we incorporated the quantification of aggressive interactions between pairs of animals in the estimation of indirect social genetic effects on skin lesions in the anterior part of the body in growing pigs. The data consisted of 491 pigs (215 barrows and 276 gilts, mean of 66 ±5 days of age). Animals were housed in 37 pens (11 to 15 pigs by pen) over 7 replicates. Trained scorers counted the number of skin lesions immediately before and 24 hours after mixing pigs. Animals were video-recorded for 9 hours post mixing and trained observers quantified the type and duration of aggressive interactions between pairs of pigs. The number of skin lesions in the frontal part of the body 24 hours post-mixing was the response variable and the number of seconds that pairs of animals spent engaged in reciprocal fights was used to quantify the intensity of interaction. We compared three different models: A direct genetic additive model (DGE), a traditional social genetic effect model (TSGE) assuming uniform interactions, and an improved social genetic effect model (ISGE) that used intensity of interaction to parameterize social genetic effects. All models included fixed effects of sex, replicate, lesion scorer, initial weight and pre-mixing lesion count; a random effect of pen; and a random direct genetic effect. The model ISGE recovered the most variance (smallest σe2) and resulted in the highest estimated h2 (P < 0.005). The model TSGE produced estimates that did not differ significantly from DGE (P = 1). Contrarily, incorporating the intensity of interaction into the modeling of ISGE allowed direct and indirect genetic effects to be estimated separately, even in a small dataset.
66 A genome-wide association study for gestation length in swine
Authors: See Garrett , Trenhaile-Gannemann Melanie , Ciobanu Daniel , Spangler Matthew L , Mote Benny
Published: July 2019

The objective of the current study was to conduct a genome-wide association on gestation length (GL) in different parities in swine. Sows (n = 831) belonging to the University of Nebraska – Lincoln resource population (Landrace X Nebraska Index Line) were utilized. GL was defined as the number of days between the final insemination and farrowing. Four traits, GL at parity 1, 2, 3 and 4 (GL1, GL2, GL3 and GL4, respectively) were investigated. Animals which were induced 24h prior to a farrowing event were removed from the analysis. Sows were genotyped with the Illumina SNP60 BeadArray. A Bayes C model with π=0.995 was implemented with fixed effects of contemporary group, development pen, diet, linear and quadratic terms for age at puberty (GL1; P < 0.01), and linear and quadratic terms for farrowing age (GL2; P < 0.01). Results are posterior means of 55,000 samples.Single marker association analysis (SMA) was performed in R utilizing a linear model on SNP from 1-Mb windows (n = 10) which explained the largest proportion of genetic variation in GL1. Top 10 (0.5% of all windows) 1-Mb windows accounted for a limited proportion of genetic variance, 7.75, 4.66, 3.45 and 2.05% in GL1, GL2, GL3 and GL4, respectively. Posterior mean heritability estimates (posterior SD) for GL1, GL2, GL3 and GL4 were 0.33 (0.06), 0.34 (0.07), 0.32 (0.08) and 0.20 (0.08), respectively. The top SNP (ASGA0017859, SSC4, 7.8 Mb) located in one of the two top common genomic regions associated with GL1, GL2 and GL3 displayed a difference of 1.1d in GL1 between alternate homozygotes (P < 0.01). The top SNP from nine of the ten regions were significant (P < 0.05) in the SMA. Two of these regions were in common with GL2 and GL3 where SNP with potential functional effects were found in ZFAT, MAML2 and CCDC82. Results suggest GL is a largely polygenic trait.
69 The effects of feeding a novel saccharomyces cerevisiae feed additive on the prevalence and abundance of antimicrobial resistance genes in the microbiome(s) of receiving beef calves
Authors: Sommer-Lassa Morgan M , Reecy James , Severin Andrew , Somwarpet-Seetharam Arun , Mayes Mary Sue
Published: July 2019

Antimicrobial resistance (AMR) is a growing worldwide health threat. Increases in AMR are preventing the success of therapeutic treatment(s), which leads to diminished animal well-being. Innovative research is needed to explore alternatives (i.e. feed supplementation) to reduce the dependencies of antibiotics in livestock production. Diet composition has previously been shown to play a large role in altering microbial communities. The objective of this project was to evaluate the effect a novel Saccharomyces cerevisiae feed additive on the abundance and prevalence of AMR genes present in beef cattle microbiomes (nasal, deep nasopharyngeal cavities, and fecal matter). Samples were collected from weaned steers (n = 32). Steers were fed four different dietary treatments (Control, 12 g/hd/day, 18 g/hd/day, post-transportation 18/g/hd/day). Analyses performed evaluated if AMR gene abundance or prevalence was reduced due to treatment. DNA samples were extracted and whole genome shotgun sequencing was conducted by Illumina Technologies. Sequences were mapped to the UMD 3.1 Bovine reference genome and the National Database of Antibiotic Resistant Organisms (NDARO) (n2= 4,187) to annotate and quantify microbial AMR genes. Hundreds of AMR genes were detected across fecal (371), nasal (363), and deep nasopharyngeal (121) samples. Nasal and deep nasopharyngeal samples primarily aligned to the bovine genome and were not analyzed further. DNA from fecal samples aligned predominantly with microbial genes and were the primary focus of the research. Linear models and treatment contrast analyses were implemented to test for nominally significant treatment differences (P < 0.05). Dietary treatment significantly impacted AMR genes, predominantly Mef(EN2) and Lnu(AN2). On average, Lnu(AN2) and Mef(EN2) AMR gene read abundances were reduced due to dietary treatments by 57% and 55%. In conclusion, feeding this novel Saccharomyces cerevisiae feed additive did significantly reduce AMR gene read abundances. However, further research will increase our understanding of dietary treatment impacts within the fecal microbiome.
73 Effects of vegetable and animal protein sources and nutrient specifications on the nursery pig gut microbiome
Authors: Creager Chloe M , Manu Hayford , Sharma Ashok , Baidoo S K , Gomez Andres
Published: July 2019

The objective of the study was to investigate the effect of different protein sources and nutrient specification levels on the gut microbiome composition of nursery pigs. A total of 120 crossbred gilts (Large White ′ Landrace ′ Duroc, initial BW 6.74 ± 0.06 kg, 18 days of age) were allotted to 1 of 6 treatments: animal protein source with nursery diet specifications (AN); animal protein source with grower diet specifications (AG); plant protein source with nursery specifications (PN); plant protein source with grower diet specifications (PG); plant protein source, nursery diet specifications, and an enzyme + essential oil cocktail (PN+EOE), and plant protein source, grower diet specifications, and an enzyme + essential oil cocktail (PG+EOE). There were 4 pigs per replicate and 5 replications per treatment, in a randomized block design. On d 43, 1 pig per replicate was sacrificed, and cecum and colon digesta samples were collected for gut microbiome analysis and profiled though MiSeq 16S rRNA sequencing. Data were analyzed using univariate and multivariate methods within R. No differences in alpha or beta diversity were detected based on protein source, nursery diet specification, or inclusion of EOE; however, a number of discriminating taxa were present between pigs fed treatments with different protein sources. For instance, abundance of Parabacteroides was increased in colonic PG samples (P = 0.01) compared with AG, and abundance of Lachnospiraceae was increased in all samples of AG compared with PG (P = 0.009). Eubacterium (P = 0.044) and Turicibacter (P = 0.031) were both more abundant in colonic AN samples when compared with PN samples. In conclusion, the gut microbial communities, at large, in the cecum or colon, were not significantly modified by the presence of different protein sources in nursery diets.