bluuebunny/crossref_metadata_2025 huggingface dataset:
228 Effect of exogenous glucoamylase inclusion on in vitro digestion and feedlot cattle performance
Authors: Pittaluga Alejandro , Yu Shukun , Li Wenting , McCann Joshua C
Published: November 2020

The objective was to evaluate the effect of adding an exogenous glucoamylase (GA) enzyme to a finishing diet on in vitro digestion and performance of feedlot cattle. Experiment 1 evaluated 3 levels of added enzyme (0, 0.24, and 0.72 GA enzyme units) and 2 corn particle sizes (2 and 4 mm) in a 7 h in vitro batch culture fermentation. No interactions were observed (P > 0.10). Addition of GA increased (P < 0.01) in vitro dry matter disappearance by 9%. A smaller corn particle increased (P < 0.01) in vitro dry matter disappearance by 11%. In Experiment 2, Angus × Simmental steers (N = 105; BW = 340 ± 39 kg) were blocked by weight and assigned to 15 pens. Pens were randomly assigned to one of 3 treatments: control (CON) diet with no added enzymes, low inclusion of GA (122 enzyme units/kg DM; LGA), or high inclusion of GA (183 enzyme units/kg DM; HGA). Steers were fed a basal diet consisting of 60% dry rolled corn, 17.5% modified distillers grains with solubles, 12.5% corn silage, and 10% of a corn-based supplement on a DM basis for 139 d. Inclusion of GA did not affect (P ≥ 0.24) final BW, DMI, or ADG overall for the 136 d feeding period. Steers fed HGA had increased (P = 0.02) G:F compared with LGA and CON with least square means of 0.213, 0.194, and 0.197, respectively. Inclusion of GA did not affect (P ≥ 0.19) carcass traits including HCW, 12th rib fat thickness, yield grade, longissimus muscle area, or marbling score. Overall, results suggest inclusion of exogenous glucoamylase enzyme increased in vitro dry matter disappearance in batch culture and improved feed conversion of the finishing diet fed to feedlot steers at 0.381 g enzyme protein/kg DM.
227 Impact of feeding Aspergillus subspecies (ssp.) blend and different corn processing methods on finishing beef cattle performance and carcass characteristics
Authors: Hopfauf Stacia M , Boyd Bradley M , McPhillips Levi J , Erickson Galen E
Published: November 2020

The objective of this study was to evaluate the effect of feeding Aspergillus ssp. blend in combination with dry-rolled (DRC) or high-moisture corn (HMC) based finishing diets on performance and carcass characteristics. Crossbred beef steers (n = 320; initial BW = 267 ± 9 kg) were utilized in a generalized randomized block design. Cattle were assigned randomly to pens by initial body weight (BW) and pens were assigned randomly to one of four treatments with 8 pens per treatment for simple effect means. Treatments were set up as a 2 × 2 factorial arrangement with factors consisting of corn processing and 0 g / steer daily or 10 g / steer daily Aspergillus ssp. blend. There were no significant interactions (P ≥ 0.23) observed between corn processing and Aspergillus ssp. blend in the diet; therefore, only main effects are discussed. For the main effect of Aspergillus ssp. blend; no significant differences were observed for dry-matter intake (DMI), average daily gain (ADG), feed efficiency (G:F), hot carcass weight (HCW), or carcass traits (P ≥ 0.78). Cattle fed Aspergillus ssp. blend had a greater 12th rib fat (P = 0.05). For the main effect of corn processing, cattle fed DRC had heavier HCW and final BW (P = 0.04), greater ADG (P = 0.05), and greater DMI (P < 0.01). However, steers fed HMC had greater G:F (P < 0.01) compared to DRC. These data suggest that feeding Aspergillus ssp. blend in either with dry-rolled or high moisture corn diets did not significantly improve performance or carcass characteristics in finishing beef steers. While feeding HMC improved feed efficiency compared to DRC, feeding DRC increased ADG (and also DMI) compared to HMC.
294 Effects of bedding application on growth performance and carcass traits in finishing beef steers during the winter and spring in eastern South Dakota
Authors: Smerchek Dathan , Smith Zachary K
Published: November 2020

Two-hundred and forty Continental × English beef steers (allotment BW = 365 kg [SD 22.5]) were used in a randomized complete block design feedlot study to evaluate the effects of bedding application during the finishing phase. Steers were allotted to 30 concrete surface pens (n = 8 steers/pen) at the Ruminant Nutrition Center (RNC) in Brookings, SD. A common diet was fed that contained 2.09 Mcal/kg of NEm and 1.39 Mcal/kg of NEg and provided 30 g/ton of monensin sodium to diet DM. Pens were assigned to 1 of 2 treatments: 1) No bedding applied (NO) or 2) 1.8 kg (as-is basis) of wheat straw bedding/steer/d (BED). The first 9 pen replicates began on test 14 d prior to the last 6 pen replicates. Pen was the experimental unit; an α of 0.05 determined significance. This study was part of a factorial experiment that included steroidal implant. No interactions were detected (P ≥ 0.09). Daily ambient temperature (n = 183) averaged 4.33°C [SD 3.21] during the study. Dry matter intake was increased (P = 0.01) by 5.8% in BED compared to NO. Carcass-adjusted ADG (P = 0.01) and G:F (P = 0.01) were increased in BED by 21.0% and 14.4%, respectively. Carcass-adjusted final BW and HCW tended to differ (P ≤ 0.07) between NO and BED. Cattle from NO required an additional 35 days to achieve similar final live BW. Rib eye area (P = 0.69) did not differ between NO and BED. Dressing percentage (P = 0.01; 63.29 vs. 62.30 ± 0.410%), backfat (P = 0.01; 1.19 vs. 1.09 ± 0.410 cm), marbling (P = 0.01; 475 vs. 437 ± 6.6), and yield grade (P = 0.03; 2.95 vs. 2.81 ± 0.045) were increased in NO. Estimated metabolic rate was elevated (P = 0.02; 0.0995 vs. 0.0948 ± 0.013 Mcal/BW0.75, kg), for NO vs. BED. Bedding improved feedlot finishing phase growth performance and gain efficiency during finishing in eastern South Dakota.
PSIV-20 Impact of OutPace® Feed Additive on nursery pig growth performance: A meta-analysis
Authors: Bass Benjamin , Crowder Stacie , Weeden Terry , Rao Murali Raghavendra , de Rodas Brenda , Karnezos Theodore
Published: November 2020

OutPace® Feed Additive (OP), contains a carefully researched blend of activated medium chain fatty acids (MCFAs; PMI, Arden Hills, MN), formulated to help mitigate the effects of stress in nursery pigs. Several studies using OP in both late and full nursery periods resulted in improved pig performance. A meta-analysis using 9 studies (4 studies during late nursery [15 to 26.8 kg BW] and 5 studies during the full nursery [5.9 to 25.4 kg]) was done to determine the impact of OP (included at 0.25% Phase 1 and 2; 0.125% Phase 3) on average daily gain, average daily feed intake, and feed conversion. The combined data was considered a randomized complete block design. Analysis of variance was completed with mixed models using the GLIMMIX procedure of SAS (SAS 9.4, SAS Institute Inc., Cary, NC) and least squares means were compared using Fisher’s least significant difference (P < 0.05). In the analysis of 5 studies conducted in late nursery (45 pens/treatment of 6 to 20 pigs/pen), pigs provided OP had higher average daily gain (0.67 vs 0.63 kg/d; P < 0.05), increased average daily feed intake (0.99 vs 0.97 kg/d; P < 0.05), and improved feed efficiency (0.67 vs 0.65 kg gain/kg feed intake; P < 0.05) compared to pigs fed control diets. Additionally, when pigs were provided OP throughout the nursery period (20 pens/treatment of 7 to 20 pigs/pen), average daily gain was increased 6.1% (0.48 vs 0.45 kg/d; P < 0.05), average daily feed intake tended to be increased 2.2% (0.62 vs 0.61 kg/d; P < 0.1), and feed efficiency was improved 2.7% (0.76 vs 0.74 kg gain/kg feed intake; P < 0.05) compared to pigs provided control diets. In conclusion, providing OP to pigs during the nursery period improved ADG and feed efficiency.
PSVIII-14 Impact of altering Lys:energy ratio during gestation on offspring post-wean growth performance
Authors: Bruhn Tiffany , Frobose Hyatt , Levesque Crystal L
Published: November 2020

Lysine and energy supply in gestation can influence preweaning mortality and sow lactation feed intake but little data exists for the impact on offspring post-weaning performance. A study evaluated the effects of dietary Lys:energy during gestation on offspring performance from weaning until market. Both primiparous and multiparous females (n=59 in 2 groups) were blocked by parity, balanced by weight and allotted to one of three gestation feeding regimens: 1.50 g SID Lys/Mcal ME (Control), 1.50 g SID Lys/Mcal ME from d2–89 and 2.11 g SID Lys/Mcal ME from d90–110 d of gestation (PF1) and 1.25, 1.07, and 0.88 g SID Lys/Mcal ME from d2–89 for gilts, parity 1 and parity 2+, respectively and 2.11 g SID Lys/Mcal ME from d90–110 d of gestation (PF2). Offspring (n=682) were weaned into 40 pens by maternal treatment (n=13-15 pigs/pen, mixed gender/pen). Pen feed disappearance and individual pig weights were determined at least once each month until market. Animals were marketed by a technician blinded to treatment; to account for potential marketing bias, adjusted d130 weight was calculated. Data were analyzed as a randomized complete block with means separation using Scheffe’s adjustment. The offspring of Control sows had decreased BW at weaning (P < 0.001) versus PF1 offspring and Control offspring had decreased BW (P = 0.001) compared to both PF1 and PF2 at d7 post-weaning. Despite minimal differences in ADG, ADFI, or G:F between treatments, PF2 offspring were heavier (P = 0.02) at market and adjusted d130 weight than Control pigs. While PF1 offspring had similar BW at market than Controls, they spent fewer (138.2 vs. 142.7; P = 0.009) days on feed than Control pigs due to the aforementioned marketing bias. Altered Lys:energy ratio in a single gestation cycle improved offspring post-wean performance.
PSIII-8 Impact of SYNOVEX® ONE GRASS implantation during suckling on pre-weaning calf growth performance
Authors: Newton Shane , Dahmer Payton , Corah Larry , Harmoney Keith , Jaeger John , Jones Cassandra K
Published: November 2020

Historic data supports the use of pre-weaning implants to maximize beef calf weaning weight, but their use has declined over the recent decade. A total of 96 beef steers (initially 85.2 kg BW and > 45 d of age) were used in a 168-d study to evaluate the effects of Synovex C® implantation during suckling on pre-weaning calf growth performance. At initial processing, calves were individually weighed and allotted in a completely randomized design to one of two treatments: 1) not implanted (control) or 2) implanted with 150 mg of trenbolone acetate and 21 mg of estradiol benzoate (SYNOVEX® ONE GRASS, Zoetis, Kalamazoo, MI). All calves were weighed on d 0 (implantation), 83, 126 and 168 (weaning), with ADG calculated for each period. Data were analyzed using the GLIMMIX procedure of SAS (v9.4, Cary, NC). There were 48 replicates per treatment, with grazing location as a random effect. While there were no detected differences in BW during the initial phases (P > 0.10), implanted calves tended to have greater (P = 0.100) greater weaning weight than non-implanted calves (279 vs. 265 kg, respectively). Calves implanted with SYNOVEX® ONE GRASS had 0.8, 0.12, and 0.16 kg/d greater (P < 0.05) ADG than those that were not implanted in all three phases. This resulted in an average of 0.10 kg/d greater (P = 0.002) ADG in implanted calves overall compared to the control. In conclusion, this research showed significant increases in suckling calf ADG in implanted calves compared to their non-implanted counterparts, which led to a tendency for 14-kg greater weaning weights. Additional research is warranted to consider the post-weaning growth and impact of re-implanting, but this data reinforces previous literature that suckling calf implantation continues to be cost effective for cow-calf producers.
16 Opportunities and challenges from deep-phenotyping of dairy cattle
Authors: Cole John B , Eaglen Sophie A E , Maltecca Christian , Mulder Han A , Pryce Jennie
Published: November 2020

Genetic selection has been a very successful tool for the long-term improvement of livestock populations, and the rapid adoption of genomic selection over the last decade has doubled the rate of gain in some populations. However, the full expression of genetic potential requires that animals are placed in environments that support such performance. Increasingly complex dairy cattle production systems require that all aspects of animal performance are measured across individuals’ lifetimes. Selection emphasis is shifting away from traits related to animal productivity towards those related to efficient resource utilization and increased animal welfare. However, phenotypes for many of these new traits are difficult or expensive to measure, or both. This is driving interest in sensor-based systems that provide continuous measurements of the farm environment, individual animal performance, and detailed milk composition. The goal of phenomics is to provide information for making decisions related to on-farm management, as well as genetic improvement. However, many challenges accompany these new technologies, including a lack of standardization, the need for high-speed Internet connections, increased computational requirements, and training to integrate these tools with more traditional management tools. There also is a lack of translational research on the use of these data for real-time precision management. We will identify opportunities and challenges associated with phenomics and discuss on-farm applications of these new tools.
402 Audio information retrieval for describing gait patterns in Brazilian horses
Authors: Ventura Ricardo V , Lopes Rafael Z , Andrietta Lucas T , Bussiman Fernando , Balieiro Julio , carvalheiro Roberto , Silva Fabyano , Brito Luiz , Alves Anderson
Published: November 2020

The Brazilian gaited horse industry is growing steadily, even after a recession period that affected different economic sectors in the whole country. Recent numbers suggested an increase on the exports, which reveals the relevance of this horse market segment. Horses are classified according to the gait criteria, which divide the horses in two groups associated with the animal movements: lateral (Marcha Picada) or diagonal (Marcha_Batida). These two gait groups usually show remarkable differences related to speed and number of steps per fixed unit of time, among other factors. Audio retrieval refers to the process of information extraction obtained from audio signals. This new data analysis area, in comparison to traditional methods to evaluate and classify gait types (as, for example, human subjective evaluation and video monitoring), provides a potential method to collect phenotypes in a reduced cost manner. Audio files (n = 80) were obtained after extracting audio features from freely available YouTube videos. Videos were manually labeled according to the two gait groups (Marcha Picada or Marcha Batida) and thirty animals were used after a quality control filter step. This study aimed to investigate different metrics associated with audio signal processing, in order to first cluster animals according to the gait type and subsequently include additional traits that could be useful to improve accuracy during the identification of genetically superior animals. Twenty-eight metrics, based on frequency or physical audio aspects, were carried out individually or in groups of relative importance to perform Principal Component Analysis (PCA), as well as to describe the two gait types. The PCA results indicated that over 87% of the animals were correctly clustered. Challenges regarding environmental interferences and noises must be further investigated. These first findings suggest that audio information retrieval could potentially be implemented in animal breeding programs, aiming to improve horse gait.
68 Assessing the Performance of Multiple Grass-fed Beef Production Systems in California
Authors: Klopatek Sarah C , Duarte Toni , Yang Crystal , Oltjen James W
Published: November 2020

With demand for grass-fed beef continuing to increase, there is an immediate need to determine animal performance and product quality from varying grass-fed systems. Therefore, using a whole systems approach, we investigated the performance and carcass quality of multiple grass-fed beef systems in California. The treatments included: 1) steers stocked on pasture, then feedyard finished for 140 days (CON); 2) steers grass-fed for 20 months (20GF); 3) steers grass-fed for 20 months with a 45-day grain finish (GR45); and 4) steers grass-fed for 25 months (25GF). The data were analyzed using a mixed model procedure in R. Final body weight (FBW) varied significantly between treatments (P < 0.05) with the CON cattle finishing at 626 kg and GF20 finishing with the lowest FBW of 478 kg. There were no significant differences in FBW between GF45 and GF25 treatments (P > 0.05), with FBW equaling 551 kg and 570 kg, respectively. Dressing percentage (DP) differed significantly between all treatments (P < 0.05), with CON DP at 61.8%, followed by GR45 at 57.5%, GF25 at 53.4%, and GF20 at 50.3%. Marbling scores and quality grades were significantly higher for CON compared to all other treatments (P < 0.05), with a marbling score of 421; 14% of CON animals graded select and 85% graded choice or upper choice. Cattle in the GR20 had the lowest marbling score of 285 (P < 0.05); 59% of the GR20 cattle graded select and 41% graded standard. There was no difference in marbling when comparing the GF25 and GR45 (P > 0.5). In addition, carcasses graded similarly between the two treatments with GF25 grading 13% standard 82% select, and 6% choice, GR45 graded 85% select and 15% choice. The findings from this study indicate that varying CA grass-fed beef production systems results in significant differences in both animal performance and meat quality.
84 Effects of incremental conditioning and supplemental dietary tryptophan on pre, mid, and post-exercise heart rate and respiratory rate in sled dogs
Authors: Thornton Emma , Templeman James , Bower Michael , Cant John , Holloway Graham , Shoveller Anna-Kate
Published: November 2020

Repetitive bouts of resistance and aerobic exercise can have dramatic effects on whole body physiology. Dietary tryptophan supplementation supports protein turnover and serotonin production, which assist in responses to exercise. The objective of this study was to investigate the effects of a 12-week incremental exercise regimen and supplemental dietary tryptophan on pre-, mid-, and post-exercise heart rate and respiratory rate in sled dogs. Sixteen dogs (mean age of 4.8 ± 2.5 years, body weight 24.3 ± 4.3 kg) were blocked for sex, age, and body weight, and randomly allocated to a control diet or the control plus tryptophan diet (tryptophan to large-neutral-amino-acid ratio of 0.075:1). All dogs participated in a 12-week conditioning regimen with controlled exercise challenges at week -1 and subsequently every 3 weeks. Electrocardiogram electrodes and thoracic rib bands were worn to record heart rate and respiratory rate (EMKA Tech., Falls Church, VA, USA) prior to, during, and following each exercise challenge. A trans regression, mixed, and correlation model were used where appropriate to assess the fixed effects of treatment and week, and explore linear relationships between recovery time and week in SAS (v 9.4). No differences were found in heart rate between treatment groups for any training level (P > 0.10). Working, recovery, and time required for heart rate to recover post-exercise decreased from week -1 to week 11 (P < 0.05). Correlation analysis indicated that treatment dogs recovered respiratory rate faster post-exercise compared to control (r = -0.421, P < 0.05). Resting, recovery and time required for respiratory rate to recover post-exercise decreased from baseline to week 11 (P < 0.05). This data suggests improvement in cardiorespiratory fitness was observed over 12 weeks of training and that tryptophan may support respiratory function during exercise recovery.
347 Choosing an external marker for measuring intake and digestibility in ruminants
Authors: Scholljegerdes Eric J
Published: November 2020

Proper nutrition is key to maintaining and improving animal productivity. Measuring intake and site and extent of digestion is essential for appropriate diet formulation. However, it is extremely difficult to accurately account for the dynamic nature of the ruminant digestive tract. External markers have long been used as a tool to measure digesta output, yet proper marker selection can be challenging. The aim of this review is to provide guidance in the selection of external markers in ruminant nutrition studies. External markers must satisfy certain requirements in order to be considered a valid marker. These requirements include, but are not limited to, being inert in the gastrointestinal tract, mixing with the digesta, and having high recovery rate in the feces. In addition, laboratory analysis needs to be easily reproducible within and amongst laboratories. Health hazards of the marker must also be kept in mind for the laboratory worker and the animal. There are a number of elements that have been utilized as external markers. Currently in the literature, chromic oxide (Cr2O3), long-chain alkanes (C32 to C36) and titanium dioxide (TiO2) are the most commonly used external markers. Each have been extensively evaluated and have their own positive and negative attributes. Results comparing fecal recoveries has been extensively reported in various diets fed to large and small ruminants. Of the three most widely utilized external markers, all have demonstrated adequate fecal recoveries, reasonable estimates of total duodenal and fecal digesta flows or output. Therefore, the selection of the appropriate marker comes down to the ease and accuracy at which analysis can be conducted, dosage rate, minimum dosage frequency, and safety to the user and animal.
141 Effect of induction of an ipsilateral vs. contralateral accessory corpus luteum (CL) on pregnancy per AI and pregnancy loss in lactating dairy cows
Authors: Monteiro Pedro L J , Gamarra Caio A , Genari Rodrigo S , Prata Alexandre B , Barletta Rafael V , Duran Peregrino , Ochoa Julian C , Canavessi Aurea M O , Sartori Roberto , Wiltbank Milo C
Published: November 2020

Induction of accessory CL can increase circulating progesterone (P4) and potentially improve fertility; although, regression of accessory CL contralateral to the pregnancy can occur, potentially negating their benefit. In this study, primiparous (n = 377) and multiparous (n = 678) lactating Holstein cows (80.0 ± 3.3DIM, 43.2 ± 13.3 kg milk/d, and BCS = 2.85 ± 0.24) were enrolled in Presynch-Ovsynch (PGF-14d-PGF-12d-GnRH-7d-PGF-56h-GnRH-16h-AI) with AI at 81 ± 3 DIM. On d5 after AI, cows were randomly but unequally assigned as Control (n = 289) or GnRH (n = 641; 100 µg gonadorelin acetate). Blood samples were collected for P4 and ovaries evaluated by ultrasound on d5, d12, d19, d26, d33, d47, and d61. mRNA for ISGs (d19) and PSPB (d26) concentrations were evaluated and pregnancy diagnoses were done on d26, d33, d47 (also embryonic measurements), and d61. Statistical analyses were performed with PROC GLIMMIX of SAS 9.4. Ovulation to GnRH on d5 was 85.4% (577/676). Cows were designated as: Control (n = 289), Ipsilateral (n = 239), or Contralateral (n = 241). Overall P4 differed (P < 0.01) within groups (Control = 7.90 ± 0.35c, Ipsilateral = 10.5 ± 0.34a, and Contralateral = 9.55 ± 0.26a). Interestingly, 52.7% (78/148) of contralateral pregnant cows had accessory CL regression by d61 with decreases in P4 after contralateral CL regression (P < 0.001). There were no treatment differences for pregnant cows in ISG15 (P = 0.63) or Mx2 (P = 0.51) mRNA, circulating PSPB (P = 0.56), amniotic vesicle size (P = 0.89), or crown-rump length (P = 0.19) or in pregnancy/AI on d26 (P = 0.24), d33 (P = 0.67), d47 (P = 0.53), or d61 (P = 0.62; overall 50.3% [387/769]). Nevertheless, pregnancy losses between d26 and d61 were lower (P = 0.03) for ipsilateral (6.6 ± 2.3%) than contralateral (14.0 ± 3.0%) and from controls (P = 0.065; 13.7 ± 2.9%) With differences also from d26-33 (Control = 7.5 ± 2.1; Ipsilateral = 3.1 ± 1.5; Contralateral = 9.6 ± 2.5). Within contralateral group, early accessory CL regression was associated with greater pregnancy loss from d26-33 (P = 0.04) and d26-61 (P = 0.01). Thus, induction of accessory CL increases P4 and may reduce pregnancy loss, although these advantages are reduced for contralateral accessory CL, because many of these CL regress during pregnancy.
155 Effects of sustained hyperprolactinemia in late gestation on the mammary parenchymal transcriptome of gilts
Authors: Palin Marie-France , Caron Anouk , Farmer Chantal
Published: November 2020

The study objective was to determine the effects of hyperprolactinemia on the mammary parenchymal transcriptome in late-pregnant gilts. Gilts were divided into 3 groups on day 90 of gestation to receive IM injections of 1) canola oil (CTL, n = 18) until day 109 of gestation, 2) domperidone (dopamine antagonist) until day 96 (T7, n = 17) or, 3) domperidone until day 109 (T20, n = 17). Mammary glands were collected on day 110 and parenchymal tissue was sampled for transcriptomic analyses. Total RNA was isolated from 6 CTL and 6 T20 gilts for microarray analysis. The GeneChip® Porcine Gene 1.0 ST Array (19,202 genes) was used for hybridization. Array quality control, data normalization and expression level analyses were performed with the Affymetrix Expression Console and Transcriptome Analysis Console (TAC) software. Using a threshold cut-off of 1.5 fold (P < 0.05), a total of 313 upregulated and 480 downregulated gene transcripts were identified in T20 vs CTL gilts. A qPCR validation analysis of selected upregulated (n = 13) and downregulated (n = 13) genes was conducted on all animals (CTL, T7, T20). The MIXED procedure of SAS was used for statistical analyses. All selected genes were validated for the CTL vs T20 comparison (P < 0.01). Only 4 selected genes (CAMK1G, COL9A1, P2RX7, TDRD1) were downregulated in the T7 treatment (vs CTL, P < 0.05). Functional analyses of differentially expressed genes were performed using the PANTHER classification system. The top upregulated Biological Process enriched GO terms were Inflammatory Response (GO:0006954) and Response to Lipid (GO:0033993). The Positive Regulation of Cell Population Proliferation (GO:0008284) and Regulation of Cellular Catabolic Process (GO:0031329) GO terms were identified for downregulated genes. Results suggest that a sustained hyperprolactinemia during late-pregnancy (T20 treatment) may increase mammary inflammatory response and reduce cell proliferation.
176 Application of growing degree day to predict diet crude protein in rangeland beef cows
Authors: Diaz Jose M , Tolleson Douglas R , Angerer Jay P , Christian Amelia , Fox William E , Pinchak William E
Published: November 2020

We used a fecal near infrared spectroscopy (FNIRS) calibration for cattle diet crude protein (CP) to evaluate the efficacy of growing degree day (GDD) as a remotely-sensed method to monitor grazing animal nutrition. Composite fecal samples representing a herd of 24 cross bred beef cows grazing native range pastures in southwest Texas were collected along with GDD and precipitation data from April 2018 to September 2019. Regression analyses were performed to determine relationships between FNIRS-predicted diet CP and GDD within year and growing season. In 2018, FNIRS-predicted diet CP ranged from a minimum of 7.05% in August to a maximum of 9.69% in July. 2018 cumulative precipitation was 28% and 94% of the 20-year average for January-April and May-August, respectively. In 2019, FNIRS-predicted diet CP ranged from a minimum of 6.85% in September to a maximum of 12.01% in May. 2019 cumulative precipitation was 74% and 102% of the 20-year average for January-April and May-August, respectively. There were no significant (P > 0.1) simple linear relationships identified between FNIRS-predicted diet CP and GDD. There were, however, cubic exponential relationships identified in both 2018 (y = 7E-10x3 - 5E-06x2 + 0.0106x + 2.9603; R² = 0.7261; P = 0.1271) and 2019 (y = 1E-09x3 - 6E-06x2 + 0.0062x + 9.2923; R² = 0.7659; P = 0.0493). As expected, perennial range grass phenology/nutritive value (i.e. cattle diet CP) was influenced by accumulation of heat units (i.e. GDD) and precipitation. Although FNIRS is an established non-invasive method to monitor grazing animal nutrition, a remotely-sensed method to accomplish this task, such as GDD, has the potential to facilitate large-scale monitoring of grazing animal nutritional status. Our results indicate that complementary research using data from multiple locations and for more than 2 years is needed to fully evaluate these techniques.
205 Effect of supplemental trace mineral source on performance, health, and carcass characteristics in finishing beef steers
Authors: Heldt Jeff , Holland Ben , Word Alyssa , Karr Kendall
Published: November 2020

Crossbred beef steers (n = 2,420; 357 ± 16 kg BW) were used to evaluate the effects of supplemental trace mineral sources on the performance and carcass characteristics on feedlot cattle. Steers were housed in 20 pens (120–125 steers per pen) with 10 pens per treatment. Supplemental trace mineral treatments (100% DM) consisted of: control: 8.3 mg/kg of Cu (100% CuSO4), 83.4 mg/kg of Zn (64.1% ZnSO4/35.9% Zn amino acid complex), and 28.7 mg/kg of Mn (100% MnSO4); hydroxy: 8.3 mg/kg of Cu (100% basic Cu chloride), 82.9 mg/kg of Zn (100% Zn hydroxychloride), and 19.3 mg/kg of Mn (100% Mn hydroxychloride). Steers were fed trace mineral treatments for 158 d and harvested at a commercial abattoir. Data were analyzed as a randomized complete block design with pen as the experimental unit. There were no differences between treatments in DMI, ADG, feed:gain, final BW, or mortality (P ≥ 0.38); however, morbidity tended (P = 0.06) to be greater for hydroxy than control (3.44 or 2.20%, respectively). Hot carcass weight, dressing percentage, marbling score, and longissimus muscle area were unaffected (P ≥ 0.28) by treatment, though backfat tended (P = 0.07) to be greater for hydroxy compared to control (1.55 or 1.51 cm, respectively). Distributions of quality grades were not different (P ≥ 0.14) with the exception of increased (P = 0.01) Prime carcasses in control compared to hydroxy (2.57 or 1.18%, respectively). Distributions of yield grades 2, 3, and 4 were not different (P ≥ 0.17) between treatments, though percentage of carcasses assigned 1 was reduced (P = 0.01) and 5 was increased (P = 0.05) in hydroxy compared to control. These data indicate steers fed 100% hydroxychloride trace minerals perform similiarly to steers fed CuSO4, MnSO4, and a ZnSO4/Zn amino acid complex combination.
222 Partitioning of retained energy between protein and fat gain, and heat of product formation and support metabolism in growing beef cattle
Authors: Lancaster Phillip A
Published: November 2020

Multiple linear regression inaccurately computes the efficiency of energy use for protein and fat gain. The objective was to quantify efficiency of metabolizable energy use for protein and fat gain along with heats of product formation and support metabolism. A literature search was performed to compile data (31 studies, 214 treatment means) on metabolizable energy intake (MEI) and composition of empty body gain in growing steers and heifers. Data analyses were performed using R statistical package for mixed models with study as random variable. Linear regression of MEI on energy gain (EG; P < 0.001; R2 = 0.627) resulted in an estimate of metabolizable energy for maintenance (MEm) of 156 kcal/kg.75 and efficiency of ME use for gain of 0.518. Linear regression of MEI on EG as protein and fat (P < 0.001; R2 = 0.623) resulted in an estimate of MEm of 149 kcal/kg.75, and efficiency of protein (kp) and fat (kf) gain of 0.274 and 0.585, respectively, resulting in an overall efficiency of EG of 0.520. Nonlinear regression model (EG = kg*(MEI-MEm)) resulted in an estimate of MEm of 103 kcal/kg.75 and efficiency of EG of 0.342. The heat of product formation was assumed to be 0.48 (1 – 0.52) and the heat of support metabolism (HiEv) 0.18 (0.52 – 0.34). Multivariate regression was used to fit simultaneous models for EG as protein (EGp = (kp+HiEvp)*k*MEA) and fat (EGf = (kf+(0.18-HiEvp))*(1-k)*MEA). Estimates (P < 0.001) of kp and kf were 0.12 ± 0.01 and 0.63 ± 0.02, and HiEvp and proportion of ME available for protein gain (k) were 0.11 ± 0.01 and 0.75 ± 0.01, respectively. The heat of product formation and support metabolism for protein were 0.77 and 0.11, and fat were 0.30 and 0.07, respectively. In conclusion, efficiency of ME use for protein was lesser than for fat gain, and heat of support metabolism was greater for protein than fat gain.
213 Feeding essential oils and α-amylase or its association with 25-hydroxy-vitamin-D3 improves productive performance by feedlot cattle
Authors: Niehues Maria Betania , Perdigão Alexandre , Valério de Carvalho Victor V , Acedo Tiago S , Vasconcellos Guilherme S F M , Tamassia Luis Fernando , Martins Cyntia L , Millen Danilo D , Arrigoni Mário B
Published: November 2020

Our objective was to evaluate the effects of associating feed additives on performance of finishing cattle when fed a high-concentrate diet for 105 days. Twenty-four Angus-Nellore crossbred bulls (iBW, 456 ± 10.04 kg; age, 18 mo) were randomly allocated to three treatments with eight replicates per treatment (animal as experimental unit). The treatments were: 1) Control (MON) - Sodium Monensin, 26 mg/kg DM; 2) Crina® RumistarTM (CR) - a blend of essential oils, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM) and 3) CR + HyD® (25-hydroxy-vitamin-D3 at 1 mg/animal/d). The DM intake and animalsˈ weight variables were assessed individually, by using the Intergado® electronic system and the Bosch® Precision Livestock platform placed in the feedlot pen, respectively. Data were analyzed using the Mixed procedure of SAS and means comparison evaluated by Tukey test at P < 0.05. The initial BW was used as a covariate when significant. Feeding CR and CR+HyD increased DMI (13.18 and 12.82 kg vs. 10.77 kg P < 0.01) and tended to increase ADG (1.94, 1.92 vs. 1.68kg/d, P = 0.07) and final BW (654, 652 vs. 628 kg, P = 0.08) compared with MON. Likewise, animals fed CR and CR+HyD had greater carcass ADG (1.38, 1.41 vs. 1.14 kg/d, P < 0.01), and HCW (368.53 and 371.87 vs. 344.13 kg; P < 0.01) compared to MON. In addition, feeding CR+HyD increased the dressing percentage in 2.1 percent points compared with MON (57.4 vs. 55.3%; P < 0.03). The G:F and the biological efficiency were similar among treatments (P = 0.50). We conclude that including Crina® RumistarTM +HyD® can be used as a tool to increase carcass production by feedlot cattle.
390 Micronutrients, One-Carbon Metabolism, and Epigenetics: Potential Developmental and Production Outcomes
Authors: Crouse Matthew S , Caton Joel , Ward Alison K
Published: November 2020

One-carbon metabolism is the network of biochemical pathways in which methyl groups are transferred from one compound to another for methylation processes. Expansion of the core pathway connects one-carbon metabolism to polyamine synthesis, nucleotide synthesis, redox metabolism, and the citric acid cycle. One-carbon metabolites (OCM) are methyl donors and cofactors which play key roles in the one-carbon metabolism pathway and include B-vitamins (choline, vitamin B12, vitamin B6, riboflavin, and folate), minerals (cobalt and sulfur) and amino acids (methionine, serine, and glycine). One-carbon metabolites are fundamental methyl donors for epigenetic modifications. Immediately post-fertilization, the embryonic genome undergoes epigenetic remodeling, and is the time when cell division is greatest (cell divisions/total cell number). At this time OCM supplementation may have its greatest impact on programming of offspring development, growth and postnatal performance, due to established metabolic roles in epigenetics (methyl transfer), growth (polyamine and nucleotide synthesis), and energetics. Limited data are available, however, which directly investigates the developmental effects of OCM supplementation in ruminants. In dairy cows, OCM supplementation in late gestation increased calf birth weight, nutrient sensing pathway activation, and offspring performance through the pre-weaning period. Methyl deficient diets during the pre-conception period in ewes altered the offspring hepatic methylome at 90 days of gestation, as well as the body composition and insulin tolerance of ram lambs at 22-mo of age. Bovine embryonic fibroblasts cultured in vitro with increasing OCM had greater growth rates and mitochondrial respiration parameters. Additional research into the area of one-carbon metabolism and the roles that OCM supplementation may play on postnatal function will provide new knowledge that could lead to altered management practices and increased efficiency of beef cattle. USDA is an equal opportunity provider and employer.
398 Towards new feeding approaches for optimizing nutritional status, immunity and host-microbiota interactions in neonatal and weaned piglets
Authors: Lessard Martin , Blais Mylène , Talbot Guylaine , Matte J Jacques , Letellier Ann , Thibodeau Alexandre , Guay Frédéric
Published: November 2020

Lactation, feeding conditions, microbial interventions and piglet growth in the first few weeks of life have important impact on the intestinal microbiota establishment and immune system development of piglets. Indeed, colostrum and milk contain various bioactive components such as immune factors, antimicrobial peptides and oligosaccharides that contribute to maintain intestinal homeostasis and regulate interactions between microbiota and host immune system. Recent results revealed that low birth weight piglet (LBWP) with poor weight gain during the first two weeks of life develop different intestinal microbiota and immune response profiles compared to high BWP (HBWP) littermates. Consequently, piglets within litters may have different resilience to infections after weaning and benefit from feed additives in a specific manner. A study has been performed to evaluate the potential of bovine colostrum extract (BC) as replacement to plasma proteins for improving gut health and resilience to Salmonella infection in piglets. Results revealed that in weaned piglets fed BC, intestinal microbiota was differently modulated and bacterial dysbiosis induced by Salmonella was restored faster. Moreover, expression of genes involved in innate immunity such as β-defensin-2 and glutathione peroxidase-2 was respectively down- and up-regulated in BC fed piglets. A combination of dietary supplementation with BC, cupper and vitamins A and D has also been tested in LBWP and HBWP, and there is clear evidence that BC in combination with other feed additives promote growth and gut health in both LBWP and HBWP. The porcine intestinal epithelial cell line IPEC-J2 was used to better understand the functional properties of BC. Results indicated that BC improves wound healing, enhances barrier function and modulates the expression of several genes involved in innate immune response. Finally, as microbial intervention, the potential of fecal transplantation to modulate intestinal microbiota and immune system development of piglets is under investigation and will be discussed.
291 Influence of feeding amino acid complexes of zinc and copper on growth performance and carcass response of finishing steers fed ractopamine hydrochloride
Authors: Engel Chanda , Tibbetts Gary , Branine Mark
Published: November 2020

A 42-d research study evaluated effects of feeding beef steers increasing levels of dietary Zn from Zn methionine (AAC-Zn; ZINPRO, Zinpro Corporation, Eden Prairie, MN) with or without supplemental Cu from Cu amino acid complex (AAC-Cu; Availa Cu, Zinpro Corp.) concurrently with ractopamine hydrochloride (RAC; Optaflexx, Elanco Animal Health, Greenfield, IN). One hundred-twenty steers (mean BW = 624 kg), ≤ 50 d from projected harvest were randomized to three pens (40 steers/pen) equipped with GrowSafe Systems (Calgary AB, Canada) feed bunk technology. Each pen was assigned to one of three treatment diets: 1) basal finishing diet + 30 mg Zn/kg DM from AAC-Zn (CON); 2) basal finishing diet + 90 mg Zn/kg DM from AAC-Zn (AAC-Zn90); or 3) AAC-Zn90 diet + 10 mg Cu/kg DM from AAC-Cu (AAC-Zn/Cu). Following allocation to treatments, cattle were acclimated to pen cohorts and GrowSafe feed bunks for 7 days. All steers were fed 300 mg RAC∙hd-1∙d-1 starting 35 d prior to harvest. Individual feed intake measurements began with RAC feeding and continued for 35 d until cattle were shipped for harvest. Carcass data were collected from each steer. Data were analyzed with individual animal as the experimental unit using PROC MIXED and PROC GLIMMIX procedures of SAS 9.4 (SAS Institute, Cary, NC). Numerically AAC-Zn90 fed cattle had heavier carcass weights than CON and AAC-Zn/Cu. Steers fed AAC-Zn90 had greater (P = 0.02) marbling scores compared to AAC-Zn/Cu. Steers fed AAC-Zn90 had lower backfat thickness (P = 0.02) and numerically greater marbling scores compared to CON. A biphasic program of feeding a lower level of AAC-Zn for the duration of the finishing phase followed by an increased rate of AAC-Zn during RAC feeding may optimize overall live and carcass response and improve total individual animal value.
PSXII-24 Identification of selection signatures for response of American mink to Aleutian mink disease virus infection
Authors: Karimi Karim , Farid A Hossain , Myles Sean , Miar Younes
Published: November 2020

Aleutian disease (AD) is one of the most important health problems in the mink industry worldwide, leading to economic losses. We used a set of single nucleotide polymorphisms (SNPs) to detect the genomic regions potentially under selection for response to Aleutian mink disease virus (AMDV) infection in black American mink. A total of 191 mink which were inoculated with a local strain of AMDV and survived until pelting were genotyped using genotyping-by-sequencing technique. The presence of viral DNA in the spleen samples were tested by polymerase chain reaction. After filtering, 47,800 SNPs at 171 individuals were used for further analyses. Signatures of selection for response to AMDV infection were detected using fixation index (FST) and nucleotide diversity (θπ) statistics measured between negative and positive groups. The overlap of top 1% SNPs obtained from both FST and θπ scores were considered as potential selection signs. This measurement identified a total of 21 candidate regions containing 11 genes which were likely subjected to selection for viral clearance. Several identified genes were those that modulate immune system (TCF4), reproductive process (CATSPERB, MAS1 and IGF2R), response to stimulus (WNT11 and MAS1), and functions of heart (TENM4 and WNT11) and liver (IGF2R). In addition, gene ontology showed that 63.6% of detected genes (seven) were involved in binding activities (GO:0005488). These genes can be used in molecular assessment of viral clearance in American mink. The results indicated that selection for viral clearance and thus AD tolerant animals can be a feasible strategy to deal with the global AMDV infection on mink farms.
PSVII-23 Using low-moisture molasses-based blocks to supplement Ca salts of soybean oil to forage-fed beef cows
Authors: Brandão Alice , Cooke Reinaldo F , Schubach Kelsey , Colombo Eduardo , Scatolin Giovanna , Rett Bruna , Pohler Ky G
Published: November 2020

This experiment compared plasma fatty acid (FA) profile of forage-fed beef cows receiving a molasses-based supplement enriched with Ca salts of soybean oil [(CSSO); 24.7% of dry matter (DM)] via a self-fed low-moisture block (LMB) or hand-fed granular concentrate daily (CONC). Thirty-six cows were allocated to 1 of 9 drylot pens, which were enrolled in a replicated 3 x 2 Latin square design with 2 periods of 42 d. Pens were randomly assigned to receive 1 of the 3 treatments, in a manner that pens did not receive the same treatment in both periods. Cows received hay for ad libitum consumption during the study. Hay intake was recorded daily from d 0 to 42, and LMB intake was recorded from d 14 to 42. The CONC was offered at 0.420 kg/cow daily (DM basis) from d 0 to 13, and then adjusted (d 14 to 42) to match LMB intake. Average LMB intake during the initial 13 d was 0.846 ± 0.107 kg/cow daily (DM basis). Supplement DM intake did not differ (P = 0.39) between LMB and CONC cows from d 14 to 42. No treatments effects were noted (P ≥ 0.40) for hay intake, BCS, and BW. Plasma FA profile did not differ (P ≥ 0.20) between treatments on d 0. From d 14 to 42, plasma concentrations of linoleic acid, ω-6 polyunsaturated FA, and total FA were greater (P < 0.01) in CONC and LMB vs. NOSUPP cows. Plasma concentrations of these FA were also greater (P ≤ 0.03) in LMB vs. CONC cows on d 14, but did not differ (P ≥ 0.35) on d 28 and 42. Inclusion of CSSO into LMB resulted in similar incorporation of ω-6 polyunsaturated and total FA in the circulation compared with CONC offered at the same daily rate.
PSVII-12 Investigating the influence of copper supplementation on copper homeostatic genes in bovine liver
Authors: Tillquist Nicole M , Thorndyke Meghan P , Thomas Tyler A , Coleman Stephen J , Engle Terry E
Published: November 2020

The objective of this experiment was to investigate the influence of copper (Cu) supplementation on Cu homeostatic genes in bovine liver. Liver samples were obtained from multiparous cows (n = 3 cows per treatment) from a previous experiment. Treatments consisted of: 1) no supplemental Cu (-Cu; total diet contained 7.0 mg Cu/kg DM) and 2) 3 mg Cu/kg DM (+Cu; total diet contained 10.0 mg Cu/kg DM). Cows were fed their respective diets for 420 d. Liver samples were harvested immediately upon slaughter, rinsed with phosphate-buffered saline solution, diced into small pieces, and placed into RNAlater and frozen at -80°C. Total RNA was extracted from all samples, and quantitative RT-PCR was used to determine the abundance of transcripts for proteins involved in Cu homeostasis in liver tissue. The target transcripts were: ALDH2, APOA1, ATOX1, ATP7A, ATP7B, BHMT, BLVRB, CA2, CCS, COX17, CTR1, ELN, GAPDH, GLUD1, GSS, LOXL1, PDIA3, SOD1, SOD3. The relative abundance of APOA1, ATOX1, ATP7B, BLVRB, CTR1, GLUD1, LOXL1, and SOD3 mRNA was greater (P < 0.05) in cows receiving supplemental Cu when compared to cattle not receiving supplemental Cu. These data indicate possible differences in Cu homeostasis in the liver based on Cu supplementation. Further investigation is warranted to determine if a difference in the relative abundance of identified transcripts are related to differences in associated protein production and function.