bluuebunny/crossref_metadata_2025 huggingface dataset:
PSVI-15 Effect of direct-fed microbials on fecal characteristics during an acidosis induction
Authors: Huizenga Kaylie , Tondini Sara , McCann Joshua C
Published: November 2020

The objective was to investigate the effects of two direct-fed microbial dosing strategies on fecal characteristics of beef cattle during an acidosis challenge. Ruminal acidosis is a metabolic disorder in beef cattle that may contribute to hindgut acidosis. Eighteen ruminally cannulated steers (BW = 328 ± 20 kg) were used in a completely randomized design with 6 steers in each period. Two steers in each period were randomly assigned to one of three treatments: blank media (NCON), a single strain of Megasphaera elsdenii at 108 CFU (DFM1), and a combination of Megasphaera elsdenii and proprietary microbial strains at 1010 CFU per dose (DFM2). On d 1, DFM1 was dosed once and DFM2 and NCON were dosed daily at 0700 on d 1-15. A basal diet (45% forage) was fed ad libitum on d 1-7. To induce acidosis, steers were fasted for 24 h on d 8 and were fed the challenge diet (10% forage) ad libitum on d 9-15. Fecal pH was measured throughout the challenge and total feces was collected on d 11-14 to determine washed fecal particle size and observe mucin casts. Fecal pH and mucin cast score was not affected (P ≥ 0.29) by treatment. Fecal particle size in DFM1-treated steers was greater (P = 0.01) than NCON and DFM2. Fecal particle size tended (P = 0.06) to increase over time. Fecal particle size was not correlated (P ≥ 0.56) to ruminal or fecal pH. Fecal mucin cast score was positively correlated to dry matter intake (P < 0.01) and mean ruminal pH (P = 0.06). Mucin cast score may help in monitoring ongoing bouts of ruminal acidosis. Overall, results indicate direct-fed microbial treatment affected fecal particle size but not fecal pH and mucin cast score during an acidosis challenge.
PSVIII-20 Impact of soybean meal inclusion in late gestation on sow productivity and litter performance
Authors: Loucks Abigail , van Sambeek Dana , Hines Elizabeth A
Published: November 2020

Soybean meal (SBM) provides essential nutritional components to the pig beyond amino acid profile. However, the expense of SBM has led to reduced use or elimination from diets of pre-farrowing sows. Therefore, the objective of this project is to investigate the impact of variable SBM inclusion rates of late gestation diets on sow productivity during farrowing and lactation. Sows were assigned to one of four diets, two weeks prior to farrowing: A (n=15; 0% SBM, 13.5% crude protein (CP), B (n=17; 10% SBM, 13.5% CP), C (n=15; 0% SBM, 21.5% CP), D (n=15; 30% SBM, 21.5% CP). At farrowing the total born (TB), born alive (BA), mummies (MM), stillborn (SB), and birth weights (BW) were recorded. After farrowing, piglet weights were recorded daily until d 10 of lactation, and then weekly until weaning. No significant effect of SBM inclusion was observed for MM, SB, or BW (P > 0.44). A numerical increase in TB (P = 0.36) and BA (P = 0.11) was observed in litters produced from sows on diet D, with TB at 13.9 ±1.3, and BA at 13.3 ± 1.1, while diets A, B, and C had TB and BA ≤ 11.3 ± 1.6, and ≤ 10.2 ± 1.1, respectively. Litter BW, wean weight, and average daily gain were not different across diets (P ≥ 0.47). These results suggest that the inclusion rate of SBM has minimal impact on overall performance, however, continued research is needed into understanding the nutritional needs of a sow during late gestation.
PSV-22 Use of weekly quizzes in a graduate-level physiology course does not enhance student learning but may help regulate study time
Authors: McFee Renee M , Bidne Katie
Published: November 2020

Weekly quizzes are a popular method to assess student learning. Their use may increase knowledge retention via the testing effect and encourage spaced rather than massed study habits. We sought to understand the effects of weekly quizzes in a graduate-level systems physiology course. This study encompasses two academic years, 2018-2019 (Year 1, n=27) and 2019-2020 (Year 2, n=28). Four independent course units were utilized, with weekly quizzes and an end-of-unit summative exam administered during two units and just an end-of-unit exam administered during the other two units. Quizzes consisted of lower-level questions (remember, understand) while exams contained higher-level questions (apply, analyze). When weekly quizzes were not administered, lower-level questions were added to the unit exam. Identical quiz and exam questions were used for both years of the study. Treatments were reversed between Year 1 and Year 2 to account for variations in unit difficulty (Table 1). Study time was tracked via weekly student surveys. We observed a difference in quiz and exam scores between units; however, there were no differences from Year 1 and Year 2 within units. Overall weekly and non-exam week study time differed across units in Year 1, with increased study time in the first unit with quizzes. This same effect was not observed in Year 2. Between years, overall weekly and non-exam week study time was greater when quizzes were administered but only for the first unit of the year. No differences were observed between units or years in exam week study time. In both Year 1 and Year 2, hours studied per week correlated strongly with exam administration (r > 0.9) but not with quiz administration (r < 0.2). Overall, these data suggest that weekly quizzes may not enhance academic performance. They may help regulate weekly study time, but do not prevent “cramming’” before exams.
PSI-3 Effects of housing cow-calf pairs in drylots vs pasture during the summer on cow performance
Authors: Sexton Keiffer , Myerscough Megan , Chapple Wesley , Meteer William T , Trennepohl Keela , McCann Joshua C , Shike Daniel W
Published: November 2020

The objective was to evaluate the effects of maintaining cows in drylots vs pasture on beef cow performance. Spring-calving, Simmental × Angus cows (n = 108; 84 ± 11 d postpartum) were stratified by age, BW, BCS, calving date, and sex of calves and allotted to 6 groups. Groups were randomly assigned to 1 of 2 treatments for 110 d: drylot (DL) or pasture (PAST). Drylot cows were limit-fed a ration consisting of corn silage, dried distillers grains, hay, corn stalks, corn, and soybean hulls to meet protein and energy requirements. Cows on pasture were rotationally grazed and offered free-choice mineral. On d 0, cows were artificially inseminated (AI). On d 0, 53, and 110 (weaning), cow BW and BCS were measured. On d 54 milk production was estimated using the weigh-suckle-weigh technique. Data were analyzed using the MIXED procedure of SAS. All binary data were analyzed using the GLIMMIX procedure of SAS. On d 0 and 53, cow BW did not differ (P ≥ 0.73) between DL and PAST. On d 110, DL cows had 74 kg greater (P < 0.01) BW than PAST cows. The BCS did not differ (P ≥ 0.66) between treatments. There was no difference in milk production (P = 0.93); however, drylot cows tended (P = 0.10) to have reduced milk fat percentage and had reduced (P < 0.01) milk urea nitrogen. There was no difference (P ≥ 0.34) in AI or overall pregnancy rates between treatments. There was no difference in foot angle or claw set (P ≥ 0.17) of cows at any time point. There was also no difference (P = 0.17) in foot treatments between DL (39%) and PAST (4%). Housing cows in drylots compared to pasture increased BW, but did not affect BCS, milk production, and pregnancy rates.
PSIII-13 The Effects of Corn Gluten Feed and Corn Dried Distillers Grains as a Replacement for Soybean Meal on Boer Type Goat Diets
Authors: Costigan Samantha , Crane Alison , Lattimer James M , Jones Cassandra K
Published: November 2020

The objective of this study was to evaluate the efficacy of corn dried distillers grains with solubles (DDGS) or corn gluten feed (CGF) as a replacement for soybean meal (SBM) in a Boer goat diet. A total of 75 meat goat kids (26.9 0.2 kg) were placed in 25 pens (3 kids per pen and 5 pens per treatment) for a 35-day experimental period at the Kansas State University Sheep and Meat Goat Center. Kids were allotted to one of the following isocaloric and isonitrogenous diets that varied in protein source: 1) SBM; 2) 100% DDGS/0% CGF; 3) 66% DDGS/33% CGF; 4) 33% DDGS/66% CGF; and 5) 0% DDGS/100% CGF. Diets were pelleted and supplied the sole source of nutrition. Goats and feeders were weighed weekly to determine ADG, ADFI, G:F, cost per kg of diet, and cost per kg of gain. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst., Cary, NC) with pen serving as the experimental unit. Differences were considered significant if P0.05. Treatment did not impact BW (P = 0.999), ADG (P = 0.723), ADFI (P = 0.210), or G:F (P = 0.796; Table 2). While diet cost differed due to differences in price of soybean meal and the corn co-products, there was no evidence (P = 0.941) that cost per kg of gain was less for goats fed the corn co-products. However, feed cost per goat was less (P = 0.0008) with diets containing corn co-products, regardless of level. These data allow producers to make more informed feeding decisions with a broader understanding of potential implications of corn gluten feed use in goats.
3 Changes in growth performance, feeding behaviors, and posture behaviors of growing pigs subjected to low-intensity heat stress
Authors: Anderson Lauren E , Holt Jonathan P , van Heugten Eric , Poole Daniel H
Published: November 2020

This study was to determine the impact of low-intensity heat stress on frequency and duration of feeding, drinking, ventral lying, and lying lateral lying behaviors. Pigs (n = 64; 24.6 ± 3.7 kg BW) were housed four per pen in thermoneutral conditions (CON; 23.9 °C ± 2.5 °C) or constant high ambient temperatures (HS; 28.7 °C ± 1.3 °C) for 16 d, followed by thermoneutral conditions (24.4 °C ± 1.8 °C) for both groups through d 21, and subsequent heat stress (28.0 °C ± 3.0 °C) for both groups through d 30. Eight focal pigs (2 pens/treatment) were video-recorded on d 3, 6, 10, 13, 20, and 29 at three time periods (morning: 0600-0800, afternoon: 1200–1400, evening: 1800–2000). Heat stress reduced ADG (HS: 1.00 kg/d, CON: 1.13 kg/d; P = 0.020) from d 14 through d 21, tended to reduce ADFI (HS: 2.14 kg/d, CON: 2.24 kg/d; P = 0.085), and increased GF (HS: 0.62, CON: 0.52; P = 0.006) from d 1 through d 7. Surface body temperature from d 2 through d 15 was greater in HS than CON pigs (mean: 39.4 °C, 37.6 °C, respectively), and was lower on d 18 for HS than CON pigs (36.4 °C vs. 37.8 °C, respectively) and d 22 (38.6 °C vs 39.3 °C, respectively). A treatment x day x time interaction for feeding duration (P = 0.003) showed CON pigs spent longer at the feeder in the morning of d 6 than HS (22.70 min, 8.97 min, respectively), but CON spent less time than HS during d 6 evening (8.78 min, 19.57 min, respectively). HS pigs visited the feeder more frequently in the evening (14.4 bouts) than CON pigs (7.8 bouts; P = 0.029). Low-intensity heat stress negatively impacted performance and altered time of feeding duration and frequency, indicating feeding behavior may be a useful heat stress predictor.
41 Estimating the heritability of meat quality traits in turkeys
Authors: Vanderhout Ryley J , Yahiro Michelle , Wood Benjamin , Barbut Shai , Mohr Jeff S , Baes Christine F
Published: November 2020

Genetic selection for improved meat quality traits has been successfully implemented in many livestock species. The objective of this study was to estimate the heritability of several meat quality traits to assess their selection potential in turkeys. Pedigree toms (n = 1,033) were processed at a commercial facility and live weight, breast meat yield (as a percentage of live weight), ultimate pH, color (CIELAB values), drip loss, cooking loss, and shear force were recorded on M. pectoralis superficialis (fillet). White striping was also rated on a 1–4 scale. Heritabilities were estimated using univariate animal models in ASReml version 4.1. Hatch week and age at slaughter were included as fixed effects in the mode,l and 32 generations of pedigree records were used. Breast meat yield (h2 = 0.62; SE = 0.090) showed the highest heritability and was higher compared to previous estimates, probably due to the smaller sample size. Live weight (h2 = 0.31; SE = 0.078), ultimate pH (h2 = 0.36; SE = 0.087), lightness (h2 = 0.28; SE = 0.086), redness (h2 = 0.22; SE = 0.075), and white striping score (h2 = 0.27; SE = 0.085) all had moderate heritabilities. The estimate for ultimate pH was similar to previous studies in broilers but was high compared to previous studies in turkeys. Estimates for color were similar to those found in previous studies involving turkeys. Drip loss and cooking loss had similar heritability estimates of 0.13 (SE = 0.071) and 0.10 (SE = 0.064), respectively, which were akin to previous estimates in pork. Shear force (h2 = 0.02; SE = 0.056) was found to have a very low heritability. In conclusion, the heritability estimates provided in this study show great potential for the inclusion of meat quality traits in selection programs of turkeys. This study is part of a larger project working towards the implementation of genomic information in the selection of turkeys for improved meat quality.
15 Host genetics of antibody response to PRRS vaccination and infection in growing pigs
Authors: Neveau Megan , Sanglard Leticia P , Dekkers Jack C , Little Erin , Dee Scott A , Hanson Dan B , Mathur Pramod , Knol Egbert , Eggert John , Dunkelberger Jenelle , Serão Nick V
Published: November 2020

Antibody response to Porcine Reproductive and Respiratory Syndrome (PRRS) vaccination and infection has been shown to be highly heritable in gilts and sows. This trait, measured as sample-to-positive (S/P) ratio, has been proposed as a selection tool for improved reproductive performance in sows. However, this novel trait has not yet been explored in growing pigs. Therefore, the objective of this study was to estimate genetic parameters for S/P in PRRS-challenged nursery pigs. A total of 854 PRRS-naïve crossbred barrows and gilts (51.9±4.8 d and 17.8±4.6 kg) were randomly allocated to 54 pens in two rooms and vaccinated with a modified live virus PRRS vaccine. Twenty-eight days later (d0), all animals were experimentally inoculated with a highly virulent strain of PRRS virus. Body weight (BW), S/P, and clinical signs of disease were recorded at this time and again at d13. Average daily gain (ADG) was calculated and used in combination with clinical signs to create two distinct groups, robust (R) and susceptible (S), with ~230 animals each. At d42, S/P was measured only in these classified animals. Genetic parameters and effect of classification were estimated for S/P for each collection day. Heritability estimates for S/P were 0.07±0.06, 0.52±0.09, and 0.43±0.28, for d0, d13, and d42, respectively. Genetic correlation estimates were high between collection days, ranging from 0.91±0.31 (d0 and d42) to 0.98±0.03 (d13 and d42). There was an effect of classification for S/P only at d13 (P=0.024), with R showing greater S/P (1.7±0.03) than S (1.64±0.03). These results indicate that, in PRRS-challenged growing pigs, S/P is highly heritable at later collection days, and differences in S/P exist between robust and susceptible animals.
27 Genomic relationship between antibody response to porcine reproductive and respiratory syndrome virus vaccination and reproductive performance in commercial sows
Authors: Sanglard Leticia P , Fernando Rohan , Gray Kent A , Linhares Daniel C , Dekkers Jack C , Niederwerder Megan C , Serão Nick V
Published: November 2020

Antibody response, measured as sample-to-positive ratio (S/P), to porcine reproductive and respiratory syndrome (PRRS) after PRRS outbreaks has been proposed as an indicator trait to improve reproductive performance in PRRS-infected sows. However, waiting for a PRRS outbreak to occur and having different relationships in healthy pigs may limit the use of this trait. Thus, we proposed to investigate if this relationship also occurs between S/P to PRRS vaccination and reproductive performance in sows without exposure to PRRS. Nine hundred six F1 replacement gilts (139□17 days old) from two commercial farms were vaccinated with a commercial modified live PRRS virus vaccine. Blood samples were collected at 52 days after vaccination to measure S/P to PRRS and SNP genotyping. Reproductive performance included: number born alive (NBA), number of piglets weaned, number born mummified (MUM), number stillborn (NSB), and pre-weaning mortality (PWM) at parities (P) 1 to 3. Average performance was calculated for each trait per sow per year (PSY). Farrowing rate and age at first service were also analyzed. BayesC0 was used to estimate genetic correlations between S/P and reproductive performance. Bivariate genome-wide association studies of antibody response and reproductive traits were performed using BayesB. High genetic correlations between S/P and farrowing performance were identified for NBA_P1 (0.61±0.16), PWM_P2 (-0.64±0.15), PWM_P2 (-0.63±0.20), NSB_P3 (-0.84±0.05), MUM_P3 (-0.83±0.11), and NSB_PSY (-0.90±0.05). A QTL was identified on chromosome 7 (MHC region) for these reproductive traits and for S/P, explaining from 1.2% (PWM_P2) to 22.4% (S/P) of the genetic variance. SNP H3GA0020505 explained most of the variance in this region for these traits. Heterozygote animals for this SNP had overall better performance: greater S/P (P = 0.001), greater (P = 0.06) NBA_P1, and lesser (P = 0.06) MUM_P3 than other genotypes. These results suggest that antibody response to PRRS vaccination may be used as a genetic indicator to improve reproductive performance in commercial pigs.
19 Mature size and other trait differences in cows selected for calving ease and growth
Authors: Bennett Gary L , Keele John W , Thallman R Mark , Snelling Warren M , Freetly Harvey C , Kuehn Larry A
Published: November 2020

Cows selected for heifer calving ease and yearling weight might also show changes in other important traits. Cattle from select and control lines within 7 populations were selected for reduced heifer calving difficulty EPD (select) or for average birth weight EPD (control) and for identical yearling weight EPD (select and control). Heifers randomly sampled within sire and born in the 4th and 5th of 7 years of selection were retained until 6 years of age with culling for once open and health, but not for other performance. Both lines were bred to the same bulls for calves born during the 3 years post-selection. Select line heifers were 7% lighter (-2.6 ± 0.5 kg, P < 0.01) at birth and not different at weaning (0.2 ± 1.5 kg) or yearling ages (-2.1 ± 2.7 kg). Select cow mature weights estimated by Brody growth curves were 5.2% lighter (-32.9 ± 3.7 kg, P < 0.01) and heights were 2.2% shorter (-3.0 ± 0.7 cm, P < 0.01) than controls. Calf weaning weights were not different. Interactions between 1st calving select (bred to select bulls) and control heifers (bred to control bulls) vs. older cows (all bred to the same bulls) were significant for survival (P < 0.01) and calving assistance (P = 0.03). Select line heifers increased calf survival (86.8% vs. 70.9%) and had decreased calving assistance (16.4% vs. 39.3%), but differences in cows for these traits were negligible. Calves born per select cow exposed exceeded those born per control cow only for 2nd calving (7.1%, P = 0.04), possibly due to reduced calving difficulty as heifers. Selection for calving ease and yearling weight resulted in cows with smaller mature size and similar or better calving ease, calf survival, and calf weaning weight. USDA is an equal opportunity provider and employer.
295 Parameter estimation under genomic selection
Authors: Misztal Ignacy
Published: November 2020

Genetic parameters are important in animal breeding for many tasks, including as input to a model for genetic evaluation, to estimate genetic gain due to selection, and to estimate correlated response due to selection on major traits. Before the genomic era, parameter estimation was facilitated by sparse structure of mixed model equations. Methods such as AI REML with sparse matrix inversion or MCMC via Gibbs sampling could estimate parameters for populations exceeding 1 million animals. With genomic selection (GS) and single-step GBLUP, the genomic matrices are mostly dense, and costs of parameter estimation increased dramatically. The estimation with 20K genotyped animals can take many days. Details in matching pedigree and genomic information influence estimated parameters. Estimation without the genomic information when GS is practiced leads to biases due to genomic-preselection. Truncating data to too few generations or to only genotyped animals leads to additional biases by excluding data on which the selection was practiced. Current studies indicate strong declines in heritability due to GS. Regular models for parameter estimation compute parameters only for the base population. Models that trace changes of parameters over time, such as random regression model on year of birth or a multiple trait model treating times slices as separate traits, are very expensive. A good compromise in parameter estimation under GS is to use slices of only 2–3 generations, with genotypes of young animals removed. When complete populations are genotyped, estimations with large number of genotyped animals are possible either with a SNP model or with GBLUP (inversion of genomic relationship matrix by APY algorithm). For simple models, Method R can provide estimates for any data size. An indirect indication of changing parameters over time is reduced predictivity or lower genetic trend despite increased data. Parameter estimation in GS would benefit from new, efficient tools.
306 Economic perspectives on biosecurity decision-making
Authors: Schulz Lee , Tonsor Glynn
Published: November 2020

African swine fever and many other livestock diseases present a host of challenges with a myriad of private and public good considerations. Chief among these challenges is identifying what drives livestock producer, self-protecting biosecurity efforts. Biosecurity adoption is an example of a private behavior that generates positive spillovers affecting the supply of a public good, that is, disease prevention. Encouraging producers to undertake specific biosecurity practices has proven useful in containing previous outbreaks of livestock disease in the United States, such as porcine epidemic diarrhea virus. Motivating producers to change production and management practices when a disease is not currently present in the United States can be much more difficult because of the (perceived or actual) lower probability of risk. National surveys of livestock producers were conducted to gain insight into decisions regarding ongoing and prospective biosecurity investment. Findings suggest producer and operation characteristics and diverse views on expected frequency of disease outbreaks, anticipated disease duration, and possible financial impact on operations underlie current and likely future biosecurity adoption. Furthermore, results point to both policy (e.g., indemnity provisions and cost sharing strategies) and market signals (e.g. market access and/or premiums paid or discounts incurred) from upstream livestock buyers have potential to incentivize biosecurity efforts.
69 A new frame score system for Nelore cattle
Authors: Sainz Roberto D , Guimarães Nayanny , Magnabosco Cláudio U , Lopes Fernando
Published: November 2020

Frame score (FS) systems for beef cattle generally represent the relationships among growth, body composition, reproduction and mature size, in a simple and practical form. This study aimed to: 1) develop a FS system for Nelore cattle that is biologically sound, easy to interpret, and useful for producers; and 2) estimate the genetic parameters of the FS with productive and reproductive traits. An arbitrary scale (1 to 12) was devised so that each unit corresponds to 15 kg of carcass weight (1 @), as this is a common measure used for marketing beef cattle in Brazil. Therefore, ideal carcass weight, defined as having 6 mm of backfat, would be 18 @ (269 kg) and 15 @ (224 kg) for FS = 6 males and females, respectively. Data from 36,030 animals (22,405 males, 13,565 females) raised on pasture were obtained from participating herds of the National Association of Breeders and Researchers (ANCP). Genetic parameters were estimated in uni- and bicharacteristic analyses under an animal model, using the EM-REML algorithm (AIREMLF90) and Bayesian inference (GIBBS1F90). The heritability estimate for the new FS was 0.38, and its additive genetic correlations were 0.70, 0.72, 0.77, 0.33, -0.57, 0.27, and 0.28 with BW at 365 d, BW at 450 d, hip height, longissimus muscle area, subcutaneous fat thickness, scrotal circumference at 450 d, and age at first calving, respectively. The estimated heritability and genetic correlations indicate that there is enough additive genetic variability to allow for genetic response to selection. The estimates support the notion that larger frame animals are taller, heavier, leaner and later maturing, both in body composition as well as sexually. The new frame score may be a useful tool for genetic selection of animals that are best suited to their environment.
315 Formation, persistence, and function of soil organic matter: how recent scientific advances apply in agroecosystems
Authors: Lavallee Jocelyn M , Cotrufo Francesca
Published: November 2020

Soil organic matter is fundamental to healthy and productive soils and building it is an effective means by which to draw down atmospheric greenhouse gas concentrations with added co-benefits. Scientific understanding of soil organic matter dynamics is constantly evolving, and the past decade has seen major advances and paradigm shifts. Soil organic matter creation from decaying plant litter is now thought to occur under two separate pathways, yielding two functionally different types: predominantly plant-derived, unprotected particulate organic matter (POM) and predominantly microbially-derived, mineral-associated organic matter (MAOM). The idea of naturally-occurring humic substances in soils has been largely abandoned, and long-term soil organic matter persistence is now understood to be driven mainly by mineral association. We will present the research behind these paradigm shifts, and show how considering POM and MAOM separately is key to understanding the mechanisms driving carbon accrual and persistence in soil, and therefore to guiding policy and management for soil carbon sequestration. We will present drivers of POM and MAOM contents, from individual fields to continents, including their capacity for sequestration and saturation in agricultural soils of the USA, and their responses to common management practices in agroecosystems.
83 The acute effects of feeding a grain-free diet with or without methionine, taurine or methyl donor/acceptor supplementation on plasma and whole blood amino acid concentrations in dogs
Authors: Banton Sydney , Pezzali Julia G , Donadelli Renan Antunes , Bakovic Marica , Wood Katharine M , Verbrugghe Adronie , Shoveller Anna-Kate
Published: November 2020

Grain-free pet foods have been sold for over a decade and comprise more than 40% of dog and cat diets sold today. Grain-free diets replace grain ingredients with pulse ingredients, which are high in lysine but low in methionine and cysteine, the precursor amino acids to taurine synthesis in the dog. The objective of this study was to evaluate the postprandial response of plasma methionine and taurine and whole blood taurine concentrations of dogs fed a grain-free diet without supplementation (CON) or with methionine (MET), taurine (TAU) or creatine, carnitine and choline (CCC) supplementation. Eight Beagles were pair housed and fed one of the four experimental diets for seven days in a 4x4 Latin Square Design. On the morning of d 7, cephalic catheters were placed and one fasted sample (0 min) and nine post-meal blood samples (15, 30, 60, 90, 120, 180, 240, 300 and 360 min) were collected. Data were analyzed as repeated measures using the PROC GLIMMIX function in SAS (Version 9.4). Dogs supplemented with MET had significantly higher plasma methionine concentrations from 30 to 360 minutes post-meal compared to dogs on CON, TAU and CCC treatments (P < 0.05). However, no differences were observed in plasma methionine concentrations between CON, TAU and CCC treatments at any time point (P > 0.05). Plasma taurine concentrations were significantly higher across time points in all treatment groups compared to CON (P < 0.05). Whole blood taurine concentrations tended to be higher across time points in MET and TAU treatment groups compared to CCC (P = 0.0513). Overall, MET, TAU and CCC supplementation increased plasma taurine concentrations compared to CON, but only MET supplementation increased plasma methionine concentrations from 30 to 360 minutes post-meal.
328 Targeting food formulation considering nutrient intake
Authors: Carciofi Aulus Cavalieri
Published: November 2020

Since the last publication of NRC (2006), dog and cat nutritionists have a good starting point to formulate pet food, once the Committee included the “recommended allowances” (RA) in the nutrient requirement tables, both expressed per dry matter (DM) or food metabolizable energy (ME). According to the Committee, the RA means “…where applicable, includes a safety factor for nutrients with uncertain bioavailability.” This is certainly important for many situations, but does not solve all concerns related to achieve a complete nutrient supply for a specific individual. This presentation will discuss the implications of the wide diversity of animals’ energy requirements, and consequently food and nutrient consumption that dogs and cats may experience along their life cycle and housing conditions. Thus, Diet Diversity, or products with diverse energy and nutrient densities, is important to drive veterinarians and nutritionists to the better food selection to fulfill nutrient requirements of specific individuals. Although data from NRC (2006) based on food ME correct distortions of DM intake related to available energy content of diets, this approach does not correct for the diversity of energy requirement among individuals, as well known for dogs (Bermingham et al., 2014) and cats (Bermingham et al., 2010). The problem is reinforced by the value assumed by NRC (2006) to estimate energy intake in adult dogs (130k cal/kg 0.75/day) and cats (100k cal/kg 0.67/day), far distant from the real energy expenditure of several (maybe most) home-living animals. A meta-analysis study showed that the NRC (2006) equation quite substantially overestimated energy requirements and food intake for cats under 4.5 kg of BW. House-living dogs (Thes et al., 2016) may need only 98k cal (per kg 0.75/day) when in ideal body condition to keep BW constant, while 120k cal when lean, and 86k cal when obese. The substantial variation among individuals is also important; considering the obese dogs group, for example, the 25% quartile value was lower (62k cal) than the 75% quartile (105k cal), showing that to achieve the adequate nutrient intake for obese animals with low energy requirement might be a challenge, due to the low DM intake (Thes et al., 2016). Based on the clinical experience of the presenter, managing a clinical nutrition service inside a teaching veterinary hospital, and a research experience with energy metabolism of cats and dogs, the presentation will explore the implications of energy requirements on nutrient intake, and how to better address NRC standards in practical formulations.
331 Dietary methionine restriction: an approach to treating obesity that does not involve food restriction
Authors: Gettys Thomas W
Published: November 2020

Dietary methionine restriction (MR) produces an integrated series of metabolic and physiological responses that develop quickly after introducing the diet. Collectively, these responses to the diet improve many biomarkers of metabolic health. Two prominent physiological responses are increases in energy intake and expenditure, with the larger effect on energy expenditure slowing ongoing fat deposition by increasing the proportion of total energy intake required for maintenance of existing tissue. A significant remaining obstacle in implementing dietary MR in a translational context will be to develop methionine-restricted diets that are palatable to higher metazoans.
324 Milk Fat Globule Membrane from Bovine Milk on Brain Development of Early Life
Authors: Donovan Sharon , Dilger Ryan N
Published: November 2020

The milk fat globule membrane (MFGM) is instrumental for the fat delivery system into human and bovine milk, but is typically removed during the manufacture of infant formula. MFGM contains components that may impact neurodevelopment, including sialic acid, gangliosides, sphingomyelin, choline, glycerophospholipids, proteins, and cholesterol. This presentation will review the clinical trial evidence linking MFGM supplementation to beneficial outcomes in infants and will describe potential mechanistic evidence linking MFGM with neurocognitive outcomes arising from preclinical studies in piglets. Infants fed formula supplemented with a MFGM (4% total protein) from 2 to 6 months of age had improved neurocognitive development at 1 year of age compared to infants fed standard formula. Infants fed formula with MFGM (5.0 g/L) and lactoferrin (0.6 g/L) for 1 year had an accelerated neurodevelopmental profile at 1 year and improved language subcategories at 18 months compared to infants fed a standard formula. To investigate potential mechanisms, piglets were fed a CONT formula or a TEST formula with MFGM and lactoferrin at the same concentrations from 2 to 31 days of age. Piglets underwent spatial T-maze testing to assess learning and memory, and magnetic resonance imaging to measure brain micro- and macrostructure. TEST piglets had lower radial and mean diffusivities in the internal capsule, suggesting greater myelination. The internal capsule contains motor and sensory projections from the cortex to corticospinal tract. Piglets on the CONT diet displayed shorter latency to choice in the T-maze compared to TEST piglets, potentially indicating anxiety-like behaviors or greater impulsivity. Aspects of the microbiome-gut-brain-axis (MGBA) were investigated to uncover potential mechanisms. TEST piglets had higher protein abundance of tyrosine hydroxylase and vasoactive intestinal peptide, longer villi and greater disaccharidase activity in the small intestine and differences in microbial abundances in the ascending colon and feces, suggesting potential modulation of the MGBA by MFGM.
344 The Ag Guide serves as a primary standard for animal scientists and AAALAC accreditation of Ag research programs
Authors: Salak-Johnson Janeen
Published: November 2020

Institutions that engage in animal research and production must ensure that high standards of animal care and use meet expectations of society while being ethical stewards of the animals they use in research. In order to achieve engagement in best practices, the Ag Guide is the most appropriate standard for assessing agricultural animals used in research and teaching. The Ag Guide minimizes the potential to overuse performance standards while enhancing the ability to appropriately address specific performance-derived exceptions to situations for which they have been validated. The primary objectives of the standards established in the Ag Guide are well-aligned with the goals of the AAALAC International accreditation program. The Ag Guide provides scientifically-sound, performance-based approaches to animal care and housing, which meet the expectations of AAALAC’s accreditation program. AAALAC provides a third-party peer review of all facets of the animal care and use program that serves as an effective mechanism to ensure institutions meet the standards of the Ag Guide. The process is designed to help identify the strengths and weaknesses of the program to ensure high-quality scientific outcomes and a high level of animal welfare. AAALAC accreditation program for agricultural animal research program is built on the cornerstone of the Ag Guide standards and connects science and responsible animal care. AAALAC accreditation promotes a comprehensive, institutionally supported program with a commitment to continuous improvement, humane and ethical animal care resulting in high-quality animal welfare, and scientific validity. AAALAC takes the position that, in accredited programs, the housing and care for agricultural animals should meet the standards that prevail on a high-quality, well-managed farm and the Ag Guide serves as this foundation. Therefore, the use of the Ag Guide for agricultural animal programs ensures a review that is based on science, professional judgment, and the best interests of the animal.
90 Effectiveness of an Educational Program on Beef Bull Selection that Incorporates Classroom Instruction and a Mock Auction
Authors: Bullock Darrh , VanValin Katherine , Lehmkuhler Jeffery , Anderson Leslie , Crites Benjamin , Laurent Kevin , Spangler Matthew L , Weaber Robert
Published: November 2020

An educational program was developed to assist beef producers with making informed bull purchasing decisions. There are two core pieces to this decision: targeting the bull’s genetics to the producer’s management and resources, and paying a price that maximizes the return on investment. This was a two-part educational program; the first session was classroom instruction with topics related to proper bull selection. At the conclusion of this session producers were assigned one of five management scenarios and received a sale catalogue with 60 bulls. Videos of all bulls were made available, along with all production information, including adjusted measurements, EPD and indices. The producers were tasked with returning the next week to attend the mock auction and purchase the best valued bull for their assigned scenario. At the conclusion of the auction, each scenario was discussed and the individual that purchased the best value bull in each scenario was recognized. Value was determined as the price paid for the bull compared to a price determined through an “economic selection index” equation. Beef producers (n = 322) participated in the program over 9 locations; in locations with less attendance, a reduced sale catalogue was used. Of the post-program survey respondents (n = 155), 71% were commercial beef producers, 27% were seedstock producers and 5% were Extension agents (n = 10, were cross classified). When asked how much time they spent reviewing the materials before the mock sale 8% said they made their decision at the sale, 16% spent 30 minutes or less, 58% spent 30 minutes to 2 hours and 18% spent over 2 hours preparing. When asked if the program would help with their next bull purchase, 88% said it would probably or definitely help. The conclusion was that this was a valuable educational program.
92 Brix as an Indicator of Energy Value in Alfalfa and Orchardgrass Herbage
Authors: Soder Kathy J , Billman Eric D , Horst Jeff , Balk Kristi , Hafla Aimee
Published: November 2020

This study correlated Brix values (measure of total dissolved solids via refractometer) with wet-lab analyses (WLA) of sugar concentrations in fresh herbage of two forage species, alfalfa (ALF; Medicago sativa) and orchardgrass (ORG; Dactylis glomerata) to estimate energy value of pastures. Four monthly samplings occurred from May-August, 2019. At each sampling, eight ALF and ORG samples were collected from established monocultures of each species. Solubles were extracted from fresh herbage using a hand-held garlic press. Triplicate Brix readings were recorded per sample using a digital refractometer. Fresh herbage samples were flash-frozen in liquid N, freeze-dried, and analyzed via WLA for total and individual (glucose and fructose) sugar concentrations, as well as nutritive value (CP, NDF, and ADF; Agri-King, Inc., Fulton, IL). The TDN, RFV, and RFQ were calculated. Brix values were correlated with WLA using the PROC CORR procedure in SAS, with significance established at P < 0.05 and trends at 0.05 < P < 0.10. Brix values were negatively correlated (P < 0.001) with WLA of total sugars (-0.65), glucose (-0.6), and fructose (-0.68) in ORG while no significant correlations (P > 0.10) were detected in ALF. Conversely, Brix values of ORG and ALF were positively correlated (P < 0.01) with NDF (0.57 – 0.58) and hemicellulose (0.42 – 0.55), as well as with ADF in ALF (0.54). Brix was negatively correlated (P < 0.05) with CP in ALF (-0.41), but there was no correlation (P > 0.10) with ORG. No correlations (P > 0.10) were detected between Brix and TDN, RFV, and RFQ. These results indicate that the Brix index does not directly translate to forage quality, particularly sugar concentrations, of ALF and ORG, and may inadvertently select herbage with increased fiber concentrations. Producers should consider more accurate methods, such as WLA, for assessing energy value of pastures.
354 ASAS-EAAP Talk: The subclinical non-aureus staphylococcal mastitis in dairy cows: a lipidomics approach
Authors: Ceciliani Fabrizio , Audano Matteo , Addis Filippa , Mitro Nico , Caruso Donatella , Lecchi Cristina , Ghaffari Morteza Hosseini , Albertini Mariangela , Tangorra Francesco , Bronzo Valerio
Published: November 2020

This study aims to determine the untargeted lipidome of cow milk during non-staphylococcal sub-clinical mastitis. Dairy cow mastitis severely impacts the dairy industry by reducing milk yield and quality and increasing culling rate. Among the pathogens that cause bovine sub-clinical mastitis, non-aureus staphylococci (NAS) have become the most frequently isolated bacteria from milk samples. The molecular mechanisms regulating the mammary gland inflammatory responses to NAS are unclear. Although the application of system biology approaches to mastitis has provided pivotal information by investigating the transcriptome, proteome, and metabolome, the milk lipidome remains undisclosed. We determined the lipidome of 17 dairy cows with NAS sub-clinical mastitis (SM) and we compared the results with the lipidome of the milk of 13 healthy cows. The study was carried out following a liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) approach. Sixteen subclasses of lipids were identified in both groups of animals. From 2,506 measured lipids, 631 were significantly changed more than 10 folds (FDR < 0.01 in milk from cows with mastitis as compared to healthy cows. Our results point out the significant influence of NAS on the milk lipidome, contribute to the understanding of inflammatory processes in the bovine udder, and highlight potential novel biomarkers for improving mastitis diagnosis. Part of this work was carried out in “OMICs”, an advanced mass spectrometry platform established by the Università degli Studi di Milano.
109 Phytate supplementation has minimal impact on mineral digestibility in horses
Authors: Brinkley-Bissinger Katy , Cersosimo Laura M , Sullivan Kathleen E , Livingston Shannon E , Bobel Jill M , Valdes Eduardo V , Warren Lori K
Published: November 2020

Phosphorus in equine rations is supplied by inorganic mineral fortification or naturally-occurring P in forages and grains. Up to 70% of P in plant material is bound to phytate. In monogastrics like poultry and swine, phytate can reduce absorption of P and divalent cations, but the extent that this occurs in horses is unknown. This study tested the hypothesis that phytate decreases mineral digestibility in horses. Six mature Quarter Horse geldings (mean ± SE, 586 ± 19 kg, 10 ± 1.5 y) were randomly assigned to two treatments applied in a cross-over design: IP6 (Ca-Mg-phytate isolated from rice bran fed at 15 mg phytic acid/kg BW) or CON (equivalent Ca, Mg and P from inorganic minerals to match intake from IP6). The level of phytate added represented an amount present in grain-rich rations typically fed to broodmares, growing horses and performance athletes. Supplements were added to a basal diet (1.75% BW, DM basis) consisting of 75% timothy hay and 25% roughage-based concentrate. Each 14-d period had an 11-d treatment adaptation followed by a 3-d total fecal collection. After acid digestion, P was determined colorimetrically and other minerals were determined by inductively coupled plasma spectrometry. Data were analyzed using mixed model ANOVA. Intakes of Ca, P, Mg, Zn, Cu and Fe were similar between treatments (140, 72, 40, 1.05, 0.24, and 1.78 mg/kg BW respectively). Apparent P digestibility (18.8 and 17%, SEM 1.9; P = 0.41) and estimates of true P digestibility (32.8 and 30.8%, SEM 1.9; P = 0.39) were similar between CON and IP6. Apparent digestibilities of other minerals were also not affected by IP6 supplementation. Findings suggest horses have sufficient microbial phytase activity in the gastrointestinal tract to mitigate impacts of dietary phytate. Higher levels or different forms of phytate and marginal mineral intake may yield different results.
104 President Oral Presentation Pick: Sensory analysis of horse treats: a comparison between horses and humans
Authors: Francis Jesse , Thompson-Witrick Katherine , Perry Erin B
Published: November 2020

Analysis of both palatability and consumer acceptance is a critical component of product development. Though consumer sensory analysis from owners is gaining interest in companion animal species, few data are available from equine owners. The objectives of this study were to evaluate both horse preference and horse owner rating of two equine treat products. Feeding preferences of adult stock-type horses (n = 10) age 13 ± 6, body weight 539 ± 41 kg, and body condition score 5.5 ± 0.5 were assessed via paired preference test conducted in an open-frame stock with a 15 second olfaction period followed by a 3 minute consumption period. Data collected include first sniffed, first consumed, and first finished. Consumer analysis of the horse treats was conducted via hedonic rating of four attributes (appearance, size, texture, and aroma) on a 9-point Likert scale, followed by rating of purchase intent on a 5 point Likert scale. Data were analyzed using PROC FREQ and PROC TTEST in SAS version 9.4. No difference was observed for first product sniffed, consumed, or finished during the horse preference test. However, moderate positive correlations were observed between first product sniffed and consumed (P = 0.01, ф = 0.40) as well as first product consumed and finished (P < 0.01, ф = 0.48), suggesting that olfaction plays a large role in horses food choice. Consumers rated Product A lower in appearance (P < 0.01), texture (P < 0.01), and size (P < 0.01), though no difference was observed between products for aroma. Additionally, consumers rated Product A lower for purchase intent (P < 0.01), indicating aroma may not play as large of a role in product selection as visual attributes. These results indicate that both horse and consumer preference should be evaluated during product development.