bluuebunny/crossref_metadata_2025 huggingface dataset:
322 The Influence of Previous Plane of Nutrition on Grain or Grass-fed Finished Steers: Water-Related Gene Expression in the Kidney
Authors: da Silva Aghata Elins Moreira , Franco Arturo Macias , De Moura Felipe Henrique , Ferguson Bradley S , Fonseca Mozart
Published: September 2022

The extenuating stressors inherent to various beef cattle backgrounding systems in the U. S. may imprint different nutritional carryover effects of earlier stages of life onto the finishing phase. Therefore, the objective of this study was to evaluate the effects of previous plane of nutrition (PPN) onto water-related gene expression in the kidney of grain or grass finished steers. Twenty-four crossbred Angus steers were randomly distributed into either low or adequate PPN during the background phase. After 85d of backgrounding, animals were moved onto a 105-d finishing phase blocked by their PPN. The grass-finished group received only alfalfa hay, whereas the grain-finished group received a high grain diet (80% whole corn and 20% alfalfa hay). By the end of the finishing phase, animals were harvested and kidney samples were collected. Changes in gene expression of Aquaporins (AQP) -2, -3, -4, -7, ATP1A1, ATP1B1, SGK1, and CLIC1 from kidney tissue were assayed via real-time qPCR; and the 18S rRNA was used as an endogenous control. One-way ANOVA followed by Tukey post hoc analysis were conducted. When comparing grain versus grass-finished according to their PPN, ATP1B1 (P = 0.0290) was the only gene significantly different, with animals coming from a low PPN finished on grass having greater expression than for the grain-finished. However, within animals backgrounded at a low PPN, AQP3 (P = 0.0289), AQP7 (P = 0.0260), ATP1B1 (P = 0.0239), and SGK1 (P = 0.0411) were upregulated for the grass-finished animals. No differences were found for the other genes analyzed. These results suggest that PPN can impact water-related gene expression in the kidney of finishing steers; the greatest impact for water-related gene expression occurred in animals from a low PPN that were fed different finishing systems, where grass-fed animals had a greater gene expression compared with grain-fed animals.
328 Effects of Supplemental Zinc Concentration and Source on Performance and Biomarkers of Immune Status in Receiving Steers
Authors: Smerchek Dathan T , McGill Jodi , Hansen Stephanie L
Published: September 2022

Weaned Angus-crossbred steers (n = 72; 626 ± 54 lbs) were enrolled in a 42-d receiving study evaluating trace mineral (TM) source and concentration on growth performance, immune, and TM status. Steers were housed in pens of 6, equipped with GrowSafe bunks to determine individual feed disappearance. Dietary treatments (n = 24 steers/treatment) included: 1) TM from an organic source (Availa4; Zinpro Corp., Eden Prairie, MN) at 7 g∙steer-1∙d-1; for 42 d (ORG); 2) ORG for entire 42-d plus AvailaZn to provide 1,000 mg Zn∙steer-1∙d-1 for first 14 d (ORG+Z); 3) inorganic TM sources to match TM concentration in ORG (ING) for 42-d. Cattle were weighed on d -1, 0, 14, 41, and 42. Data were analyzed using Proc Mixed with fixed effect of treatment and steer as experimental unit. Initial BW was covariate for growth performance. Final BW and overall ADG did not differ (P ≥ 0.19). However, overall DMI tended to differ (P = 0.06) and G:F was greater (P = 0.04) in ORG+Z than ING, with ORG intermediate. Plasma Zn increased from d 0 to d 14, while d 14 and d 42 did not differ (Day; P = 0.02) and was unaffected by treatment (p value). Based on repeated measures, plasma Cu concentration was greater (P = 0.06) in ING than ORG+Z, while ORG was intermediate and plasma Cu concentrations decreased over time (Day; P = 0.01). Frequency of total circulating NK and CD8 T cells measured on d 0, 14, 42 did not differ (P ≥ 0.07). Markers of activation (CD16, CD44 and CD8) on NK cells measured on d 14 differed by treatment (P ≤ 0.05). In this study, organic TM supplementation improved feed efficiency in received weaned beef steers and TM supplementation influenced markers of immune function.
329 Effectiveness of Virginiamycin Administration on Animal Health and the Observed Impacts on Growth, Development, and Intake Dynamics in Growing and Finishing Calves
Authors: Batista Luiz Fernando Dias , Rivera Madeline E , Tedeschi Luis O
Published: September 2022

Virginiamycin (VM) is an antibiotic that possesses antimicrobial properties due to its ability to block protein synthase in Gram-positive bacteria. It reduces lactic acidosis and the incidence of liver abscesses. Animal growth and development is brought about because of improved ruminal health, and animal health and welfare. This study evaluated the continuous or intermittent provision of VM during the growing and finishing phases on 120 Angus-crossbred steers (291 ± 28 kg) in 20 pens equipped with a Calan gate feed system from which animals received VM (240 mg/d) as follow: no VM (T000); VM in the last 50 d (T001); VM for the last 100 d (T011); VM in the first 50 d (T100); VM in the first 100 d (T110); and VM for 150 d (T111). Data were analyzed using a random coefficients model with the pen as a random effect and animals within treatment as the subject. The T011 tended (0.075 ≥ P ≥ 0.052) to have a greater carcass, final shrunk body weight compared with T110. Empty body fat (EBF; %) tended (0.080 ≤ P ≤ 0.050) to be less for animals that consumed VM regardless of the period or length of feeding. Dry matter intake (DMI) was lesser for T111 compared with T000, and greater for T011 compared with T110 (P ≤ 0.028), which resulted in greater average daily gain (ADG) with no difference in feed efficiency (P = 0.015 and 0.225, respectively). ADG-adjusted metabolizable energy (aME) content increased by 3.08% for T111 compared with T000. This study indicated that daily supplementation of 240 mg VM during the whole feeding phase increased feed efficiency and paME, whereas when withdrawn during the end of the finishing phase (T110) can impair DMI and ADG.
341 Effects of Supplemental Betaine on Protein Deposition and Plasma Amino Acid Concentrations in Growing Steers with Modulated Methyl Group Status
Authors: Grant Madeline S , Marsh Jessica M , Hazlewood Kathryn J , Miesner Matt D , Titgemeyer Evan C
Published: September 2022

Methyl group donors (e.g., methionine, betaine) may improve performance of growing beef cattle. Our objective was to evaluate effects of betaine supplementation on protein deposition and plasma amino acids in growing steers with altered methyl group status. Seven ruminally cannulated Holstein steers (189 kg) were used in a 6×6 Latin square design with 10-d periods. Factorial treatments were continuously infused abomasally and included 3 methyl group modulators [MGM; control; 15 g/d guanidinoacetic acid (GAA); or 16.8 g/d creatine] and 2 levels of betaine (0 or 5.7 g/d betaine). Supplemental GAA or creatine increases body creatine supply; however, GAA consumes methyl groups during creatine synthesis, whereas creatine spares methyl groups by reducing GAA synthesis. Steers received 3.5 kg/d (DM basis) of a corn-based diet. Total collection of urine and feces occurred on d 7 through 9 to measure N retention. Jugular blood was collected on d 10. No interactions between MGM or betaine were observed (P≥0.17). Betaine supplementation increased retained N (P=0.03), but did not affect urinary or fecal N excretion (P≥0.16). Betaine increased plasma Met (P=0.03) and cystine (P=0.04) and tended to decrease plasma Lys (P=0.10). Nitrogen retention was not affected by MGM (P=0.63). Creatine increased urinary N (P=0.04), and GAA tended to increase urinary N (P=0.08). Creatine increased fecal N excretion relative to control (P=0.02); GAA also increased fecal N relative to control (P< 0.01). Plasma Met was not affected by MGM (P=0.41). Plasma cystine was decreased by creatine relative to control (P=0.01), but was not affected by GAA relative to control (P=0.26). Plasma Lys was decreased by GAA (P< 0.01) and creatine (P=0.05) relative to control. Supplemental betaine improved protein deposition in growing steers and altering methyl group status affected plasma amino acid concentrations.
335 25-Hydroxyvitamin D3 Associated with Essential Oils and α-Amylase Increases the Performance of Cattle in Intensive Pasture Finishing
Authors: Gouvêa Daniel I C G , Niehues Maria B , Perdigão Alexandre , de Carvalho Victor Valério , Acedo Tiago S S , Vasconcellos Guilherme S F M , Polycarpo Gustavo V , Martins Cyntia L L , Arrigoni Mário B D B
Published: September 2022

Our objective was to evaluate the use of different feed additives in the performance of beef cattle in intensive pasture finishing (TIP), fed a high level of concentrate for 96 days. Nellore bulls (n = 120; iBW 359 kg, ±5.02 kg) were distributed in randomized blocks, allocated in paddocks of 2.4 ha (Urochloa brizantha cv. Xaraés; 10 animals/paddock), with two treatments with 6 replications (paddock as experimental unit), adapted with increasing concentrate, with a target of 2% BW in concentrate DMI (DMIc) on the 10th day. The treatments were: 1) Sodium Monensin (MON), 26mg/Kg MS; 2) Crina, Rumistar + Hy-D, essential oil blend, 90 mg/kg DM + exogenous α-amylase, 560 mg/kg DM + 25 hydroxy-vitamin D3, 1mg/animal/day). The animals were weighed fasting (± 16h) at the beginning and at the end of the experimental period, the DMIc was measured daily by the difference between the offered and the leftovers. Data were evaluated using Glimmix procedure of SAS, whereby means were separated using the PDIFF statement (P < 0.05). The use of CRD increased DMIc (9.1 vs. 8.2 kg/day, P=0.0034), DMIc/BW (2.14 vs 1.97% DMI/BW, p=0.0044), ADG (1.4 vs. 1.2 kg/day, P=0.0241), and final BW (492 vs. 473kg, P=0.0085). Likewise animals fed CRD had greater carcass ADG (1.2 vs 1.0 kg/day, P=0.0034), HCW (292 vs. 277kg, P=0.0121) and tended to have greater dressing % (58.56 vs 59.34, P = 0.07). Additionally, animals fed MON had greater fluctuation in DMIc (5.28% vs 4.53% day, p=0,0278), and took longer days to reach 2% BW in DMIc (22 vs. 12 days, P< 0.05). The use of Crina® RumistarTM + Hy-D® increases carcass production of bovines under intensive pasture finishing.
350 Meta-Analysis of the Effects of Dietary Inclusion of dry Distillers Grains with Solubles (Ddgs) on Performance, Fermentation, Carcass Characteristics, and Nitrogen Efficiency in Sheep
Authors: Chelkapally Sai Chandan , Terrill Thomas H , Pech-Cervantes Andres a
Published: September 2022

We conducted a meta-analysis to evaluate the effects of dietary supplementation of dry distillers grains with solubles (DDGS) on performance, fermentation, carcass characteristics, and nitrogen efficiency in meat sheep. A total of 36 peer-reviewed manuscripts from 1997 to 2021 met the inclusion criteria for the analysis. Data from 940 sheep (29.1±11.5 kg) were used to estimate the magnitude of the effect between DDGS and control (No DDGS) treatments weighted by inverse variance using a robust variance estimation. Categorical and continuous covariates, like breed (pure or crossbreed), CP, NDF, and DDGS inclusion rate (0 to 100%) were adjusted to a mixed model to perform a meta-regression and subset analysis. Dietary DDGS increased (P < 0.05) dry matter digestibility (75.9 vs.74.9 %), neutral detergent fiber digestibility (55.9 vs. 53.8%) with respect to the control. Compared with the control, dietary DDGS increased (P < 0.01) final body weight (51.4 vs. 50.4 kg) and tended to increase (P = 0.06) average daily gain (254.1 vs. 247.6 g/d) in sheep. Similarly, dietary DDGS tended to increase (P < 0.10) hot and cold carcass weight (25.5 vs. 24.6 kg; 21.1 vs. 19.8 kg), and meat redness (16.3 vs. 16.6) compared with the control. Dietary DDGS reduced acetate molar proportions (50.1 vs. 52.0%) and acetate: propionate ratio (1.63 vs. 1.87; P = 0.02). The subset analysis revealed that breed and DDGS levels in the diet influenced yield grade and carcass weight. Dietary inclusion of DDGS linearly increased (P < 0.05) nitrogen intake and rumen NH3-N, but also urinary nitrogen. The inclusion rate of DDGS should not exceed 30% in the diet to prevent negative effects on nitrogen metabolism, rumen fermentation, and carcass characteristics in meat sheep. Collectively, this study supports the inclusion of DDGS in meat sheep diets to increase performance and meat quality.
344 Impact of Removing 20% Distillers Grains After one-Third or two-Thirds of the Feeding Period on Performance of Finishing Yearlings
Authors: Lorences Sofia Suarez , Troyer Braden C , Norman Mitch M , Loza Pablo L , Stock Rick A , MacDonald James C , Erickson Galen E
Published: September 2022

Crossbred, yearling beef steers (n = 210: initial BW = 430 ± 22 kg) were used in a randomized blocked design finishing experiment to evaluate the impact of removing modified distillers grains plus solubles (MDGS) on finishing performance and carcass characteristics. Treatments included feeding 20% MDGS (DM basis) during the entire feeding period (124 d); 20% MDGS until day 79 and then 0% MDGS until the end of the feeding period; or 20% MDGS until day 43 and then 0% MDGS until the end of the feeding period. A total of 21 pens (10 steers/pen) were used with 7 pens/treatment. Cattle were fed a 60:40 blend of high-moisture and dry-rolled corn, with 15% corn silage, 20% MDGS and 5% supplement. Distillers were replaced with the corn blend and urea when removed. Cattle were stepped down to 10% MDGS for 4 days before the complete removal of MDGS. Cattle with MDGS removed on either d 79 or d 43 had reduced (P < 0.05) final BW, DMI, and ADG. Cattle with MDGS removed on d 43 were 5% less efficient (P < 0.05) than cattle fed 20% MDGS throughout the entire feeding period. Cattle fed 20% MDGS throughout the whole feeding had the greatest (P < 0.05) HCW and LM area. There were no differences (P ≥ 0.35) in backfat and marbling scores among treatments, and no differences (P = 0.59) in percent of abscessed livers, although 38% of steers fed 20% MDGS continuously had liver abscesses compared with 46% for steers with MDGS removed on d 43. Based on the results of this study, removing MDGS from finishing diets on either day 43 or day 79 of the feeding period had a negative impact on cattle performance compared with feeding 20% MDGS continuously throughout the entire finishing period.
351 Mycotoxin Trends in US Total Mixed Rations and Corn Silage
Authors: Schwandt Erin F , Gott Paige N , Zheng Lan , Hofstetter Ursula , Levy April W
Published: September 2022

Mycotoxins are secondary fungal metabolites identified in a variety of feed ingredients and may affect animal health and productivity. This study investigated occurrence and contamination levels of mycotoxins in 2022 US total mixed ration (TMR) and 2021 corn silage samples. Corn silage samples harvested in 2021 and submitted through March 2022 and TMR samples submitted between January through March 2022 were screened via the LC-MS/MS technique for the presence of six major mycotoxin groups: aflatoxins, type A trichothecenes, type B trichothecenes (B-Trich), fumonisins (FUM), zearalenone (ZEN) and ochratoxin A. Detailed information for each sample was provided including, state of origin and whether or not clinical signs of mycotoxicosis was observed on-farm. Parameters of the main toxins found for corn silage and TMR samples were analyzed for effect of clinical concern (yes/no) and harvest year on contamination levels using LSMeans statement with Tukey's adjustment in the GLIMMIX procedure (SAS 9.4, Cary, NC). Main effects of mean contamination by harvest year are presented in Table 1, since no interactions were significant (P > 0.05). To date, 20 TMR samples from seven states have been submitted for analysis in 2022. Preliminary results show detectable amounts of B-Trich in 95% of TMR samples, with ZEN and FUM detected less frequently in 55 and 10%, respectively. Mean contamination concentrations (parts per billion, ppb) are presented on dry matter basis and were greater in 2022 compared with 2021 for B-Trich and ZEN (P < 0.05) and similar for FUM (P = 0.022). Preliminary results for 72 corn silage samples show detectable quantities of B-Trich in 90% of samples with ZEN and FUM detected less frequently in 67 and 24%, respectively. Mean contamination levels are greater than the last two years and approaching those observed in the challenging 2018 crop for B-Trich, FUM, and ZEN.
356 Neonatal Holstein Calves fed a Pelleted Calf Starter Containing a Botanical Extract and Direct fed Microbial Alone or in Combination
Authors: Casper David P , Olagunju Lydia , Anele Uchenna , Officer Michael , Klanderman Keith
Published: September 2022

Botanical extracts (BE; Adisseo North America, Altanta, GA) are known to enhance dry matter intake (DMI) and gut health, while direct-fed microbials (DFM), such as a Lactobacillus acidophilus fermentation product (RC: RumaCell DF 5G; Pacer Technology, Inc., Murtaugh, ID), had shown improved gut health and growth performance of growing Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance. Eighty 2- to 5-day old Holstein bull calves were blocked by body weight (BW) and randomly assigned to 1 of 4 treatments in a randomized complete block design. Treatments were: 1) Control: no additives; or 2) BE added at 496 mg/kg to the calf starter (CS); 3) RC added to the CS at 2.50 g/kg with RC added to the milk replacer (MR) at 5 g/d; and 4) BE&RC: BE and RC added to CS at same rates and added RC to MR. The CS was a 25% crude protein dry matter basis and MR was a 22:20 (CP:fat) fed 2x/d at 0630 and 1800 h along with free choice water. Weaning occurred after d 49 for the 70 d experiment. Calves fed RC demonstrated greater (P < 0.05) BW gain compared with calves fed BE&RC with calves fed Control and BE being intermediate and similar (63.9, 63.5, 65.0, and 59.7 kg for Control, BE, RC, and BE&RC, respectively). Total experiment DMI (MR+CS) was less (P < 0.05) for calves fed BE&RC than calves fed the remaining treatments (116.5, 114.2, 116.4, and 104.9 kg). Total experiment BW gain/DMI was greater (P < 0.05) for calves fed BE&RC compared with calves fed Control with calves fed BE and RC being intermediate and similar (0.55, 0.56, 0.56, and 0.57 kg/kg). This experiment demonstrated that specific BE should not be fed in combination with specific DFM.
358 Gastrointestinal Permeability in Unweaned Male Holstein Calves: Colostrum Consumption and Feed Restriction Matters
Authors: Pisoni Lucía , Devant Maria , Bassols Anna , Pujols Joan , Saco Yolanda , Gomez Nestor , Marti Sonia
Published: September 2022

Male Holstein calves (n = 80; 42.7 ± 1.44 kg and 14.2 ± 0.81 days of age) were used to evaluate the effects of colostrum consumption and feed restriction on gut functionality in calves subjected to an assembly center simulation (ACS). Well-colostrated (WC) calves received 4L of colostrum within the first 2h after birth and 2L of colostrum in the next 3 feedings, and poor-colostrated (PC) calves received 2L of colostrum within the first 2h after birth. At approximately 14 d of age, calves were subjected to ACS (d-4 to d-1) before a 19h-transport (d0) where they were fed 4L of milk replacer/d (moderate restriction; MO) or 4L of a rehydration solution/d (severe restriction; SV). Treatments were: WCMO, WCSV, PCMO, PCSV and a group of control calves (WCCT) also fed concentrate ad-libitum during ACS and not transported. Twenty-four hours after transportation, a gut permeability test using Cr-EDTA was performed and blood samples for the determination of serum citrulline concentration were collected. Afterwards, one-half of the calves/treatment were euthanized to obtain tissue samples for a gut permeability in vitro analysis and morphometry. Data were analyzed using the MIXED procedure of SAS. Serum Cr-EDTA concentration was greater (P< 0.01) for the WCSV and PCSV compared with the WCMO, PCMO, and WCCT had the least Cr-EDTA concentration after transportation. The PCSV, WCMO and WCSV calves had the least (P< 0.01) serum concentration of citrulline. In vitro measurements of ileum permeability tended (P=0.06) to be greater for PCSV compared with the other treatments. In WCSV, WCMO and PCSV Goblet cells numbers in the ileum were lesser (P=0.02) than in WCCT and PCMO. Feeding rehydrated solution to poor colostrated calves before transport negatively affected gut functionality as indicated by the greatest permeability to Cr-EDTA, the lest serum citrulline concentration, and ileum Globet cells numbers, these findings are supported by the in vitro gut permeability data.
357 The Effects of Colostrum Consumption and Feed Restriction on Performance, Energy Balance, and Behavior in Unweaned Male Holstein Calves Being Marketed and Transported
Authors: Pisoni Lucía , Devant Maria , Bassols Anna , Pujols Joan , Saco Yolanda , Gomez Nestor , Marti Sonia
Published: September 2022

Male Holstein calves (n = 80; 42.7 ± 1.44 kg and 14.2 ± 0.81 days of age) were used to evaluate the effects of colostrum consumption and feed restriction on performance, energy balance (serum concentration of BHB and NEFA), and behavior on calves marketed and transported during 19h. Well-colostrated (WC) calves received 4L of colostrum within the first 2h after birth and 2L of colostrum in the next 3 feedings and poor-colostrated (PC) calves received 2L of colostrum within the first 2h after birth. At approximately 14 d of age, calves were subjected to an assembly center simulation (ACS, d-4 to d-1) before a 19h-transport (d0) where they were fed 4L of milk replacer (MR)/d (moderate restriction; MO) or 4L of a rehydration solution/d (severe restriction; SV). After the ACS, treatments were: WCMO, WCSV, PCMO, PCSV and a control group (WCCT) with ad-libitum access to concentrate and not transported. From d1 to d7, all calves were fed the same diet (4L/d of MR and ad-libitum access to concentrate, straw, and water). Data were analyzed using mixed models with repeated measures. There was a time by treatment interaction (P< 0.01) for NEFA and BHB concentrations before transport being greater for the WCSV compared with PCSV calves. After the ACS, BW was reduced (P< 0.01) for the WCSV and PCSV calves compared with the WCCT, WCMO and PCMO calves. After transportation, a time by treatment interaction (P< 0.01) was observed in concentrate intake recovery being lesser for the PCSV and PCMO; it took 4 days for those calves to recover concentrate intake to the same extent that WCCT, WCMO, and PCMO. During the ACS, PCSV calves showed greater (P=0.05) standing times compared with the remaining calves. Colostrum consumption and the degree of feed restriction affect physiological, performance, and behavior responses in calves before and after transportation.
363 In Vitro dry Matter and Fiber Digestibility of Different Varieties of Peanut Tops and Bermuda Grass Forage
Authors: Baloyi Joseph J , Callaway Todd R , Lourenco Jeferson M
Published: September 2022

The objective of the current study was to evaluate the in vitro of dry matter and fiber digestibility, gas, ammonia N and volatile fatty acid production of peanut tops from seven cultivars, CB91-1, 010-13, IAC322, 13-D, 13-1014, 886 and GA-06G, grown in the state of Georgia, USA, and Bermuda grass. The peanut top samples were harvested towards the end of the growing season at about 125 days after planting and the peanut pods removed. The Bermuda grass was harvested after 4 weeks regrowth. Fresh cut peanut tops and Bermuda grass samples were analysed for dry matter (DM) content and then in vitro DM and fibre digestibility. Hydrogen, methane, pH, ammonia, total gas and volatile fatty acids (VFA) production were measured after 24 hours incubation. Analysis of variance was performed using the General Linear Model procedures of Minitab Statistical package. The peanut top varieties contained an average of 165.4 g/kgDM crude protein, and greater calcium and potassium and less phosphorus than Bermuda grass. There were no significant differences (P > 0.05) in in vitro DM digestibility, pH, hydrogen, methane, ammonia-N production. However, NDF and ADF in the Bermuda grass was significantly more digestible (P < 0.05) than the peanut varieties. The peanut tops did not differ in NDF digestibility (P > 0.05). CB91-1, IAC322 and 886 peanut tops and Bermuda grass had significantly greater (P < 0.05) ADF digestibility. There was no significant difference in the acetate contents for all seven peanut varieties (P > 0.05). The GA-06G variety had the greatest propionate and butyrate content. Bermuda grass and CB91-1 variety had the least amount of propionate, isobutryate, butyrate, isovalerate and valerate compared with other peanut varieties. Total VFA of all peanut varieties were similar, while that of Bermuda grass was the least (P < 0.05). The GA-06G had the lowest A:P ratio value compared with the other samples.
369 Effect of Diet, Rumen Fermentation Parameters and Their Combination on Predicting Milk Production
Authors: Sujani Sathya , White Robin R
Published: September 2022

The objective of this meta-analysis was to explore variability in milk production associated with rumen fermentation parameters and diet characteristics. Data were extracted from 138 journal articles and used to derive 6 models to predict MY. Each model considered a different set of independent variables, including rumen fermentation parameters (R), diet (D) and their combination (R+D), with or without interactions with rumen pH. Rumen fermentation parameters included total volatile fatty acid (VFA) concentration, molar proportions of major and minor VFA, rumen pH and ammonia nitrogen, and diet variables included dry matter intake (DMI) dietary percentages of dry (DM) and organic matter (OM), crude protein, neutral (NDF) and acid detergent fiber (ADF), ether extract, and starch. Linear mixed-effects models weighted by the inverse of the standard error were employed. Models were compared based on concordance correlation coefficients after removing random study effects (CCC). The MY models using D, R, D+R and D*pH performed similarly with CCC values ranging from 0.63 to 0.65. Models including an interaction with rumen pH were superior at explaining variation within the data (CCC: 0.75 to 0.76). The Final model derived using D, consisted of DMI and ADF. Molar proportions of acetate and propionate and DMI were in the final model based on R. The interaction between starch and pH remained in the final D*pH model along with DMI, DM, NDF and pH. From these models, we can conclude that rumen pH is an important moderator explaining variability in the associations among diet, rumen VFA, and milk production.
370 Effects of the Vasoactive Intestinal Polypeptide (VIP) for the Efficient Ruminant Product
Authors: Afrose Mia Md Golam Kafi , Hawley Emma , Yusuf Mustapha , Dorsam Glenn , Swanson Kendall C
Published: September 2022

Feeding high-grain diets can result in reduced ruminal pH, inflammation of ruminal and other tissues, and subacute ruminal acidosis. Vasoactive intestinal polypeptide (VIP), a gut hormone with anti-inflammatory and other functions, could have a beneficial role in ruminants fed high-concentrate diets. To determine the effects of VIP injection on dry matter intake, average daily gain, gain:feed, and ruminal pH, wether lambs (n=16; BW=68.5 ±1.8 kg) were blocked by body weight and randomly assigned to VIP treatment (n=8) or control (n=8). All lambs were housed in individual pens, adapted to the same high concentrate diet (75% whole corn and 25% supplemental pellet; DM basis), and feed intake and average daily gain were measured from day 1 to 21 when lambs were placed in metabolism crates. Lambs in the treatment group were injected intraperitoneally with VIP (1.3 nmol/kg BW in 0.9% NaCl), whereas lambs in the control group were injected with 0.9% NaCl every second day over 28 days. Nutrient balance was measured over the final seven days (data will be reported elsewhere), and lambs then were slaughtered and ruminal fluid and tissues collected. The average daily gain was greater (p = 0.04) in VIP treated lambs than in control lambs. However, no difference (p > 0.05) in daily feed intake was observed between treatments. Ruminal fluid pH was not significantly influenced by treatment (5.2±0.11 vs 5.0±0.11 for the control and VIP treatments, respectively). These data indicate that VIP injection may increase ADG and gain:feed in lambs fed high concentrate diets. Further research is needed to verify these results and to delineate the mechanisms responsible for the observed increases in ADG and gain:feed.
375 Genomic Approaches for Feed Efficiency in Sheep
Authors: Posbergh Christian , Schaub Daniel
Published: September 2022

United States seedstock sheep producers have selected sheep for higher weaning and post-weaning weights using estimated breeding values for approximately forty years. Despite this, little work has investigated if the increased performance has inadvertently resulted in increased feed intakes, increasing total feed costs for the producer. Eighty range-breed ewe lambs (forty Targhee and forty Rambouillet) were enrolled in a residual feed intake (RFI) trial shortly after weaning at approximately four months of age. Feed intake was recorded utilizing a GrowsafeTM feeding system modified for sheep. Following a two-week adaption period, feed intakes were recorded daily for forty-two days. Body weights were collected at the beginning, end, and weekly throughout the trial period. Residual feed intake was calculated utilizing mid-trial body weights and feed intake measurements. Six ewes were removed from the trial due to failure to adapt to the feeding system. Linear regressions were utilized to determine the association between post-weaning weight estimated breeding values and RFI and body weight. As expected, there was a significant relationship (p< 0.05) between post-weaning estimated breeding value and body weight during the trial. No statistically significant relationship between post-weaning weight estimated breeding value and RFI was identified, indicating selection for increased body weight has not resulted in decreased feed efficiency during the growth phase. Additional feed efficiency measures will be collected on these same ewes at a later life stage to represent the maintenance phase of production as opposed to the growth phase. In addition, genetic and rumen microbial analysis is ongoing. Together these approaches will aid in the construction of a framework for eventual genetic and genomic selection of feed efficiency in U.S. range sheep.
376 Genetic Approaches to Improve Reproductive Performance in the U.S. Sheep Industry
Authors: Murphy Thomas W
Published: September 2022

The U.S. sheep industry has experienced many changes over the last 50 years, the most prominent being a 75% reduction in the national breeding ewe inventory. Wool now accounts for ~10% of enterprise returns compared to ~80% from the sale of market lambs. Most breeding objective work indicates greatest emphasis should be placed on traits associated with ewe reproductive efficiency [e.g., number of lambs born/weaned (NLB/NLW), lamb survival]. Still, average NLB across the U.S. (1.07 lambs/ewe) and within geographic regions (East = 1.13, Midwest = 1.25, West = 1.09, Southwest = 0.79 lambs/ewe) remains low. Several genetic technologies are available to improve reproductive performance. Introgression of large effect gene variants, such as those within BMPR-1B, have increased NLB by ~1.0 and ~1.5 lambs in heterozygous and homozygous ewes, respectively. However, without joint improvement in maternal ability and/or husbandry, advantages in NLW are less pronounced and few U.S. producers utilize such variants in practice. Reproductive efficiency traits present challenges in selection programs as they are lowly heritable (< 0.15) and sex-limited. Previous single-trait selection experiments had modest improvement in NLB (0.01 – 0.02 lambs/yr). Selection accuracy is greatly improved by including pedigree and/or genomic relationships when deriving estimated breeding values (EBV). Since 2000, NLW EBV have increased by 0.01 lambs/yr with concurrent improvement in direct (0.02 kg/yr) and maternal (0.04 kg/yr) weaning weight for Polypay flocks enrolled in the National Sheep Improvement Program (NSIP). Still, NSIP flocks represent < 1% of production-oriented U.S. flocks so considerable expansion is needed to realize within-breed genetic improvement at a national level. Perhaps most importantly, large differences in reproductive efficiency traits exist across breeds and should be utilized to a greater extent in strategic crossbreeding systems. Optimizing reproductive performance for specific production environments is essential for the sustainability of the U.S. sheep industry.
377 Derivation and Use of Genomic Enhanced Estimated Breeding Values for Selection in Sheep
Authors: Lewis Ronald M , Brown Daniel J
Published: September 2022

The efficacy of selection programs in sheep depends on accurate evaluation of genetic merit. Globally, genetic evaluations are based on best linear unbiased prediction (BLUP) in which fixed effects and breeding values are estimated simultaneously. With genotyping becoming increasingly routine, pedigree, performance, and genomic data are being combined in single-step genomic BLUP (ssGBLUP) evaluations to generate genomic enhanced estimated breeding values (GEBV). Since GEBV are more accurate, younger animals can be selected more reliably; a corollary benefit is a shortened generation interval. Traits that are lowly heritable, expressed in one sex, measured late in life, or difficult and/or expensive to measure benefit most from genomic evaluation. Adoption of this technology has lagged in sheep most likely due to the higher cost of genotyping compared to the value of an animal. Nevertheless, genomics has been successfully incorporated in sheep breeding programs in several countries (e.g., Australia, France, New Zealand). Increases in accuracy of EBV of up to 60% have been reported. In 2021, the efficacy of genomic selection in a U.S. sheep breed (Katahdin) was tested by comparing predictive ability and bias of EBV using ssGBLUP and pedigree BLUP for weight and fecal egg counts at weaning. Approximately 5,000 animals, most born within the last 5 years, were genotyped with a 50k array. Nearly 70k body weights and 14k fecal egg counts were available. Genomic information improved predictive ability for both traits by as much as 10%, and reduced bias in the evaluation of fecal egg counts. Accuracies of EBV improved appreciably in younger genotyped animals (by as much as 1.81 times). An outcome was release of GEBV in the evaluation of U.S. Katahdin sheep. With integration of genomics into genetic evaluation, there is clear opportunity to augment the reliability of genetic evaluation and thereby rates of selection response in sheep.
380 Awardee Talk: Deer eat Birds and Other Revelations: Teaching a Changing Demographic of Animal Science Student
Authors: Scheffler Jason M
Published: September 2022

Animal Science (ANS) programs have seen the demographics of their students progressively shift to include more urban and suburban students with limited firsthand knowledge of production agriculture. A major contributor to that shift is an influx of students with the intent of pursuing veterinary school, primarily with the goal of working with companion animals. The change in students has its challenges, but also presents opportunities. It is a chance to communicate with our customers, voters, and prospective thought leaders and decision makers. It is also a chance to recruit new and diverse talent into animal agriculture to help solve current and future problems. Despite the high number of students interested in pursuing vet school, a small percentage gain admittance making it important to help students recognize alternate career paths as soon as possible. This is particularly critical at the University of Florida where 41% of our students are transfers. We questioned if the students’ focus on entering the veterinary field is due to viewing it as their best career opportunity, or their only opportunity. We conducted a career awareness survey at the start and end of the ANS3006 Introduction to Animal Science course over the past several years. Over 49% could not list more than two ANS-related careers. Veterinarian was the most common and appeared on 76% of responses. In turn, we have incorporated more career-related content into ANS3006. In the post survey evaluation, 57% listed more than two careers and 18.8% of students indicated their career goals had changed over the course of the semester, with more than 2/3 of those being students who changed from a veterinary path. Anecdotally, our advisors report students are more amenable to changing from the pre-vet track when encouraged. Emphasizing the opportunities is an effective way to help students find the career paths they may have otherwise missed.
208 Single Cell RNA Sequencing (Scrna-seq) in Studying the Early Embryonic Muscle Development
Authors: Zhao Liang , Du Min
Published: September 2022

During the early development, skeletal muscle, adipose, and connective tissues have high plasticity and are sensitive to in uterine nutritional fluctuations. During the past decade, maternal nutrition-induced changes in myogenesis and adipogenesis during the fetal stage have been extensively studied and their alterations are closely associated with changes in production efficiency and meat quality of farm animals. Organogenesis initiates during the embryonic stage, which sets the blueprint for later growth and development. Limited but growing evidence support that nutritional changes during the early embryonic stage also have profound effects on animal production efficiency. Using single-cell transcriptomic analysis (scRNA-seq), we investigated the effects of maternal obesity (MO) on the embryonic myogenesis in embryonic day 9.5 (E9.5) mouse embryos. First, we identified myogenic subpopulations within the dermomyotome (DM) and a developmental trajectory of embryonic myogenesis was reconstructed. Our results showed that MO induced systematic hypoxia, which was correlated with enhanced BMP signaling and impaired skeletal muscle differentiation within the DM. The Notch-signaling effectors, HES1 and HEY1, which act downstream of BMP signaling, were activated by hypoxia-inducible factor 1 (HIF1A) and suppressed myogenic differentiation through transcriptionally repressing an important myogenic regulator MEF2C. In conclusion, MO induces hypoxia and impairs myogenic differentiation by up-regulating BMP signaling within the DM, which may account for the disruptions of skeletal muscle development and function in progeny. Understanding the developmental programming of the skeletal muscle, as well as adipose and fibrotic tissues, especially at the embryonic stage, will facilitate the development of stage-specific nutritional management strategies to optimize production efficiency and meat quality.
209 A Single-Cell Atlas of Bovine Skeletal Muscle Tissue Reveals Mechanisms Underlying Differences in Quality between Wagyu and Brahman Beef
Authors: Fu Xing
Published: September 2022

Wagyu cattle are renowned for their premium beef characterized by abundant intramuscular fat (IMF). In contrast, Brahman, a popular breed in the southern coastal area of the US, generally produces tough meat with scarce IMF. However, the mechanisms underlying the differential meat quality between the 2 breeds are still largely unknown. Here, using single-cell RNAseq (scRNAseq), we report a single-cell atlas of bovine skeletal muscle tissue. Multiple fibro/adipogenic progenitor (FAP) subpopulations were identified, including an endomysial adipogenic subpopulation and a perimysial fibrogenic subpopulation. Further analysis comparing individual FAP subpopulations between Wagyu and Brahman identified stronger expression of pro-adipogenic genes in Wagyu adipogenic FAP subpopulation and higher expression of pro-fibrogenic genes in Brahman fibrogenic FAP subpopulation. Overexpression of CFD, a gene upregulated in Wagyu adipogenic FAPs, enhanced the adipogenic efficiency of FAPs. Moreover, the expression of CFD in FAPs was positively correlated with the IMF content. Interestingly, the expression of CFD was not identified in FAPs of mouse models of intramuscular adipogenesis, suggesting that CFD is a cattle-specific regulator of IMF formation. Cell-cell communication analysis reveals significant differences between CFD+ FAPs and CFD- FAPs in their interactions with other cell types, further suggesting an important role of CFD+ FAPs in bovine skeletal muscle growth and development.
210 Restricted Maternal Nutrition: Impacts on Fetal Development and Metabolism in Sheep
Authors: Govoni Kristen E
Published: September 2022

Adequate nutrition is important for proper growth and metabolism. This is even more important during gestation when insults to the fetus can negatively impact fetal growth and development with persistent effects into adulthood. Using a sheep model, we have demonstrated that maternal restricted feeding (60% of National Research Council requirements) during gestation reduced growth in offspring and muscle fiber cross-sectional area. These changes in growth are associated with reduced stem cell (satellite cells and mesenchymal stem cells) population and function. Offspring of restricted-fed mothers also displayed altered metabolism indicated by increased insulin resistance, leptin dysregulation, and reduced circulating metabolic and growth factors. Based on these persistent negative effects of maternal diet on offspring postnatal growth and metabolism, we evaluated the impacts during fetal growth on whole body and tissue-specific metabolism and the impact of maternal realimentation during gestation. Nutrient restriction caused changes in metabolic pathways in a tissue specific manner in muscle, liver, and blood demonstrating the ability of maternal diet to program offspring metabolism in highly metabolic tissues. Several pathways involved in amino acid, lipid, carbohydrate, and transsulfuration/methionine metabolism were altered in all 3 tissues, demonstrating the whole-body effects of maternal diet on offspring metabolism. Interestingly, realimentation alleviated some of the effects of nutrient restriction on offspring metabolic pathways. In summary, maternal nutrient restriction during gestation negatively affects offspring fetal growth with persistent effects into adulthood which may be caused by changes in stem cell function and key metabolic pathways during fetal development.
388 Young Scholar Award Talk: Increasing Efficiency of Finishing Beef Production: Optimizing Starch Digestion, Improving Flaking Quality, and Reducing Methane Emissions
Authors: Trotta Ronald J
Published: September 2022

The objectives of my dissertation research are to develop strategies to increase the efficiency of finishing beef production by optimizing the site and extent of starch digestion, improving flaking quality and consistency, and reducing methane emissions. Post-flaking sampling and handling techniques such as sifting steam-flaked corn samples with a sieve (P < 0.01), air equilibration time (P < 0.01), and storage temperature during shipping (P < 0.01) all influenced enzymatic starch availability of steam-flaked corn. Inducing starch retrogradation of steam-flaked corn decreased the rate (P < 0.01), but not the extent (P = 0.80), of ruminal dry matter degradation and thus, energetic efficiency was predicted to increase by up to 3.4% because of increased postruminal flow and digestion of starch in the small intestine. If producing steam-flaked corn is not feasible for smaller capacity feedlots, finely ground corn has a similar ruminal starch solubility to steamflaked corn (38.1% vs. 44.4, respectively, P > 0.05), suggesting an alternative processing method to increase feeding value in finishing diets. Duodenal infusion of glucoamylase (fungal origin) increased (P = 0.02) small intestinal starch disappearance in steers, while duodenal infusion of porcine α-amylase did not (P = 0.41), supporting the hypothesis that small intestinal carbohydrases are the primary hydrolytic limit to small intestinal starch digestion. Comparative sequencing analyses revealed a missing region of the stalk region of the sucrase-isomaltase protein sequence (AA 47-60) which is important for intracellular sorting of the sucrase subunit to the apical membrane. The absence of this region of the protein likely explains the absence of intestinal sucrase activity and quantitative limitations of starch digestion in the ruminant small intestine. Feeding decoquinate with Yucca schidigera extract for 7-d decreased (P < 0.01) ruminal acetate proportion and tended to increase ruminal (P = 0.08) propionate proportion, suggesting potential for hydrogen shifts which could contribute to reductions in methane emissions with longer feeding periods. The findings of my dissertation research provide: 1) post-flaking sampling and handling recommendations for commercial feedlots and laboratories to improve estimates of starch availability and flaking consistency, 2) a mechanistic target (sucrase-isomaltase) for limitations in small intestinal starch digestion, 3) practical feeding strategies to shift the site of starch digestion to the small intestine to increase feed efficiency (retrogradation), 4) new processing alternatives for small feedlot producers (fine ground corn inclusion), and 5) new information on how combinations of feed additives could potentially decrease methane production in feedlot cattle.
390 Young Scholar Award Talk: The Effect of Chronic Maternal Lipopolysaccharide Exposure During Late Gestation on Offspring Muscle Development
Authors: Bryan Erin , Bode Nick , Shirey Dani , Chen Xuenan , Dilger Ryan N , Dilger Anna
Published: September 2022

The objective of this study was to determine the effect of chronic inflammation during late gestation on offspring muscle development. Starting at gestational day (GD) 70, first-parity gilts were administered either lipopolysaccharide (LPS, n=7) or saline (CON, n=8) via jugular venipuncture every other day until GD 84. LPS was initially given at 10 µg/kg BW and was increased by 12% each instance of administration. Volume of PBS was increased accordingly. Rectal temperatures of gilts were collected at 0, 2, 3, and 4-h post injection. Gilts farrowed naturally at GD 114 (±2). At postnatal day (PND) 3, the pig closest to the average litter weight was euthanized, and the longissimus dorsi, psoas major, semitendinosus, heart, lungs, liver, and kidneys dissected and weighed. The semitendinosus was frozen in liquid N cooled-methylbutane and sectioned for muscle fiber typing analysis. Data were analyzed as a one-way ANOVA with cohort as a random effect and significance considered at (P ≤ 0.05). Gilts exposed to LPS had a 1.3°C increase in rectal temperature at 3 and 4-h post injection (P < 0.05), indicating successful induction of an inflammatory response. LPS exposure reduced (P = 0.04) the weight of piglets born alive and tended to reduce (P =0.09) the weight of piglets weaned, but did not alter the percent of pigs born alive or survival during the suckling period (P ≥ 0.29). Semitendinosus weight was also reduced (P < 0.01) in LPS pigs, and tended to be reduced (P =0.09) as a percentage of whole-body weight. However, there were no differences between treatments in any other tissues. Further, maternal LPS exposure did not alter fiber type proportions, average fiber area, or estimated number of fibers (P ≥ 0.17). Overall, these data indicate that chronic maternal LPS exposure during late gestation did not reduce offspring muscle fiber formation.