bluuebunny/crossref_metadata_2025 huggingface dataset:
190 Effects of Flooding on Grazed Pastures: Forage Quality, GHG Emissions and C Stocks
Authors: Miquilini Marina , Ribeiro Ricardo , Chiavegato Marilia
Published: September 2022

Manure creates hot spots of nutrients concentration, and consequently nutrient losses to air and water. In flood-prone areas these losses represent a major concern for environment. However, there is a gap on the understanding of the effects of recurring, short-term flooding on environmental and forage characteristics. This study evaluated the effects flooding on soil carbon (C) stock; and greenhouse gas (GHG) emissions (methane, CH4; nitrous oxide, N2O; and carbon dioxide, CO2) from soil; and forage dry matter and quality in flooded and non-flooded grazed pastures during four sampling periods (spring, early summer, late summer, and fall) of 2021. Soil samples were collected from 0-100cm, forage samples were cut at stubble height and soil greenhouse gases (GHG) emissions were monitored using the static chamber methodology. Preliminary results show trends of reduced forage digestibility in flooded pastures. No differences were observed on forage dry matter. Overall, there was no differences between CO2 emission from soil in flooded and non-flooded areas. Soil CH4 fluxes were primarily negative, and flooding seems to reduce the sink potential for CH4 from soil, except during early summer. For N2O the effects of season were very pronounced, increased emissions from spring to early summer and throughout fall in both flooded and non-flooded pastures. We did not observe any N2O sinks, and no difference between treatments. Flood-prone pastures had decreased C stock in comparison with non-flood pastures. Preliminary results show that forage production may represent a good option for flooded areas, since no effects were observed on mass and few effects on quality. However, flooding reduced C stock potential and CH4 sinks. A second sampling season will be performed in 2022 to further observe these results and allow for C-equivalent flux calculations. The balance between productivity and environmental impacts of flood-prone pastures will then be assessed.
215 Awardee Talk: Astaxanthin Supplementation During Deconditioning and Reconditioning Periods Reduces Oxidative Stress in Circulation in Polo Ponies
Authors: Kawaida Mia Y , Kwon Oh Sung , Ahn Ahram , Reiter Amanda S , Tillquist Nicole M , Reed Sarah A
Published: September 2022

Oxidative status is impacted by fitness and dietary nutrients, such as antioxidants. We hypothesized that astaxanthin (ASTX) supplementation would improve oxidative status in the circulation and muscle in response to exercise following deconditioning and reconditioning in horses. Twelve conditioned polo ponies (14.8 ± 1.7 yr) were assigned to control (CON; n = 6) or astaxanthin supplemented (ASTX; n = 6; 75 mg ASTX daily) groups. Horses performed 26 min submaximal exercise tests (SET) followed by 30 min of recovery while in condition (SET1), after 16 wk of deconditioning (SET2), and after 16 wk of reconditioning (SET3). Blood samples were collected 30 min before and 0, 15, 30, and 60 min after each SET. Semitendinosus muscle biopsies were collected 2 wk before and 2 hr after each SET. Using commercially available kits, plasma and muscle superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities and plasma malondialdehyde (MDA) concentrations were determined. At SET2, ASTX had 116% greater plasma SOD activities than CON (P=0.001). Both treatment groups increased from SET2 to SET3 (P< 0.001), but there were no treatment effects at SET3 (P=0.788). At SET2, plasma GPX activities were 49.3% greater in ASTX than CON (P=0.012), and ASTX tended to be 21.2% greater than CON at SET3 (P=0.096). Plasma MDA concentrations were 22.2% greater in CON than ASTX at SET2 (P=0.034), but not at SET1 or SET3 (P≥0.449). There were no detectable differences in muscle SOD or GPX activities 2 wk before or 2 hr after any SET (P≥0.309). In conclusion, ASTX supplementation maintained circulating antioxidant capacity and minimized oxidant activities during deconditioning, reducing oxidative stress in response to the SET in the circulation but not in the skeletal muscle. This may enable horses to adjust to strenuous exercise more efficiently, improving athletic performance, especially when they are re-introduced to exercise after deconditioning.
221 Putative Gene Regulators in the Equine Endometrium, Corpus Luteum and Embryo During Early Pregnancy in the Horse
Authors: de Amorim Mariana Diel
Published: September 2022

It is estimated that 17.3% of all pregnancies in the horse are lost from the time of detection to day 40, which has significant economic impact. But still, equine reproductive research has limited funding opportunities. Understanding the dynamics between the embryo, endometrium, and corpus luteum (CL) is essential to ameliorate those losses. Pig embryonic interferon (IFN) gamma is essential for the establishment of pregnancy. In ruminants, IFN tau is the maternal recognition signal. The equine embryo seems to express IFN alpha, gamma, delta, and epsilon but higher expression was only identified on day(D) 16 embryos, after the maternal recognition of pregnancy (MRP), so the IFN role during pregnancy is unknown. Oxytocin and prostaglandins have been demonstrated to have a role during luteolysis and luteostasis in the horse, and therefore investigation the embryonic, endometrium, and CL putative gene regulators during the equine MRP is warranted. Oxytocinase (LNPEP), an aminopeptidase that metabolizes oxytocin (OXT) has been recently investigated with other putative gene regulators in the horse during the expected time of MRP. OXT and LNPEPmRNA were identified in the equine embryo, endometrium, and CL, but OXT/neurophysin-1 protein was not detected in the embryo, and present in the CL. Most of the endometrial and luteal mRNA differences were identified around D12 post-ovulation, suggesting being a critical time for MRP. Luteal OXT was not different between pregnant and non-pregnant mares. LNPEP mRNA was upregulated in pregnant and non-pregnant mares D10 and 12 luteal tissues along with prostaglandin E synthase (PTGES). Embryonic trophoblast LNPEP and PTGES have higher relative abundance on D15 conceptus compared earlier embryos, suggesting a potential role during embryonic fixation. The increased expression of LNPEP is suggested to have a role in decreasing oxytocin availability and shifting the ratio PGE:PGF to a PGE that will support luteal function during early pregnancy.
222 Maternal Recognition of Pregnancy in the Mare: What is Needed to Make Progress in our Understanding of This Complex Issue
Authors: Klein Claudia
Published: September 2022

Maternal recognition of pregnancy (MRP) resulting in prolonged luteal lifespan is crucial to maintenance of pregnancy. Mechanisms underlying MRP differ in between species, whereat the precise mechanism by which luteolysis is prevented has yet to be described for equine pregnancy. Transcriptional profiling studies entailing analysis of endometrial and embryonic tissues have shed light into the wider context of maternal recognition of pregnancy. Our own studies revealed the secretion of fibrinogen by preimplantation equine embryos, which is a peculiar finding as fibrinogen synthesis almost exclusively occurs in the liver. Conceptus-derived fibrinogen likely contributes to cell adhesion during fixation and underlines the helpfulness of transcriptome studies in identifying species-specific aspects of early pregnancy. Despite all our advances, we yet have to decipher the signaling pathways leading to reduced endometrial production of prostaglandin F2alpha during MRP. We recently analyzed samples from mares undergoing spontaneous pregnancy loss in the face of high progesterone in comparison to samples collected from mares at Day 20 of intact pregnancy. No differentially expressed transcripts could be detected. It appears that after maternal recognition of pregnancy and consequent suppression of luteolysis, progesterone, not the presence of a viable conceptus, is the driving force of gene expression. This finding underlines the importance of understanding the events surrounding luteostasis. We propose that a standardized approach in vitro cell culture model is needed to address mechanistic questions pertaining to MRP. Approaches currently underway such as CRISPR/Cas9-mediated targeted integration of TERT and TERC to immortalize equine endometrial stromal fibroblasts will be discussed.
257 Effect of the Essential Amino Acid-Nitrogen to Total Nitrogen Ratio on Lysine Requirement for Nitrogen Retention in Growing Pigs
Authors: Camire Carley , Rodrigues Lucas Alves , Panisson Josiane C , Shoveller Anna-Kate , Columbus Daniel A
Published: September 2022

Low-protein (LP) diets may become limiting in nitrogen (N), affecting utilization of essential amino acids (EAA) for nitrogen retention (NR). The objective of the present study was to determine the effect of the EAA-N to total N ratio (EAA-N:TN) on lysine (Lys) requirement for NR. A total of 80 growing barrows (21.5±0.89 kg initial BW) were randomly assigned to 1 of 10 dietary treatments (n=8 pigs/treatment) in 8 blocks in a 2 × 5 factorial arrangement with factors of EAA-N:TN (low vs. high) and Lys content (0.82, 0.92, 1.02, 1.12, and 1.22% standardized ileal digestible [SID] Lys). Diets were formulated to meet EAA requirements with the low ratio diet (LR; 16.8% crude protein) having an ideal EAA-N:TN of 0.48 and the high ratio diet (HR; 15.5% crude protein) formulated to be limiting in NEAA with an EAA-N:TN of 0.55. Diets were fed at 2.8 × maintenance metabolizable energy requirements. After a 7-d dietary adaptation, a 4-d N-balance period was conducted where fresh fecal samples were collected daily and quantitative urine samples were collected over a 24-h period. Nitrogen-balance was determined as the difference between N intake minus fecal and urinary N output. Data were analyzed using a MIXED model with fixed effects of ratio, Lys, and their interactions, and block as a random effect. Lysine requirement based on two-phase linear or quadratic modeling was estimated using PROC NLIN. Nitrogen retention increased linearly with increasing Lys levels regardless of ratio (P< 0.01). Quadratic modelling estimated the Lys requirement to maximize NR at 17.83 g/d in pigs fed HR diets at 1.21% SID (R2 = 0.53; P< 0.05), but no breakpoint was achieved for pigs fed LR diets, which showed a linear response (R2 = 0.79; P< 0.05). These results suggest that NR is limited by NEAA or TN in HR diets.
259 Impact of Reducing Dietary Protein with Supplementation of 8 Essential Amino Acids and Functional Roles of Supplemental his or Glu on Growth Performance and Carcass Traits of Finishing Pigs
Authors: Duarte Marcos Elias E , Deng Zixiao , Baker Jonathan , Kim Sung Woo
Published: September 2022

This study evaluated the effects of reducing dietary protein with supplementation of 8 essential amino acids and functional roles of supplemental Glu or His on growth performance and carcass traits of finishing pigs. Pigs (n = 216; 98 ± 3.5 kg BW) were allotted (3 pigs/pen) to 4 treatments in a randomized complete block design (RCBD) with sex and initial BW as blocks. Pigs were fed for 14 d until 120 kg BW. Dietary treatments were CON (11.4% CP with L-Lys, L-Thr, and L-Trp); LCP (8.9% CP with L-Lys, Thr, Trp, Met, Val, Ile, Phe, and His); LCPG (9.1% CP; LCP+Glu to match % Glu in CON); and LCPH (9.2% CP; LCP+2x His requirement). Diets met or exceeded requirements with 2.7 Mcal/kg NE. Growth performance and backfat thickness (BFT) were measured at d 0 and d 14. Blood was collected to analyze BUN. At d 14, pigs with the median BW in each pen were slaughtered. Pigs fed CON had greatest (P < 0.05) BW, ADG, and G:F. Pigs fed LCP had greater (P < 0.05) BW, ADG, and ADFI than LCPG. BFT of pigs fed LCPG and LCPH was less (P < 0.05) than CON. Cold carcass weight in CON was greater (P < 0.05) than LCPG and LCPH, whereas it was greater (P < 0.05) in LCP than in LCPG. Chilling loss in LCP was less (P < 0.05) than LCPG. Drip loss at 48 h in LCPH was less (P < 0.05) than CON and LCPG. BUN in LCPG and LCPH was less (P < 0.05) than CON. In conclusion, reducing dietary protein by 2.5% using 8 supplemental amino acids reduced growth performance without affecting carcass yield. Supplemental His at 2x requirement to low protein diets meeting His requirement enhanced loin quality by reducing drip loss.
251 A Combination of Dietary Isoleucine and Valine Above Recommended Levels Improves the Growth and Alters the Metabolites Profile in Pigs fed with Very low Protein Diets
Authors: Goodarzi Parniyan , Habibi Mohammad , Gorton Matthew W , Tarkesh Firoozeh , Walsh Katherine , Fuhrig Mallory , Pezeshki Adel
Published: September 2022

Very low-protein (VLP) diets are beneficial for reducing the nitrogen excretion from swine production, but these diets depress the performance of pigs while supplemented with first four limiting amino acids (FFL; i.e. Lys, Met, Thr and Trp). The objective of this study was to investigate the effect of supplementation of Val and Ile above NRC (2012) levels on performance, thermal radiation and blood metabolites of pigs fed with VLP diets. Three-week-old weaned barrows (n = 40) were assigned to: positive control (PC): normal protein diet; negative control (NC): VLP diet containing FFL at NRC levels; HV: NC with Val above NRC; HI: NC with Ile above NRC; HVI: NC with both Val and Ile above NRC. After 5 weeks of data collection, blood samples were collected. Univariate GLM with Tukey post-hoc test was used to analyze the data (SPSS). Pigs fed with NC had a decreased average daily gain (ADG) and average daily feed intake (ADFI) compared with PC (P< 0.05). HVI pigs had less ADG than PC, but greater ADG than NC (P< 0.05). ADFI of pigs fed with HVI was similar to PC and it was greater than NC (P< 0.05). HVI pigs had a higher thermal radiation than NC (P< 0.05). While HVI pigs had greater blood glucose than PC and NC at baseline (P< 0.05), no differences among these groups were observed on postprandial blood glucose concentration. HVI pigs had less blood triglycerides than PC. All groups increased the blood cholesterol compared with PC (P< 0.05). There were no differences in blood urea nitrogen (BUN) for NC vs. PC; however, pigs fed with HVI reduced the BUN compared with NC (P< 0.05). In conclusion, supplementation of Val and Ile greater than NRC into VLP diets partially restored the performance and fully recovered the ADFI, reduced the blood triglycerides and BUN, and improved the glucose tolerance.
270 Effects of Different Watering Options on Standardized Ileal Digestibility of Amino Acids and net Energy in Diets fed to Growing Pigs
Authors: Lee Su A , Rodriguez Diego A , Stein Hans H
Published: September 2022

Two experiments were conducted to test the hypothesis that different watering options affect the standardized ileal digestibility (SID) of amino acids (AA), apparent total tract digestibility (ATTD) of dry matter (DM) and gross energy (GE), and concentration of net energy (NE) by growing pigs. A corn-soybean meal-based diet was used in both experiments. There were 3 treatments: 1) dry feeder plus a water nipple located outside the feeder, 2) wet-dry feeder with the water nipple inside the feeder, and 3) combined system with a water nipple both inside the feeder and also an outside nipple. In Exp. 1, pigs (n = 6; initial weight = 27.53 kg) that were equipped with a T-cannula in the distal ileum were allotted to the 3 treatments using a replicated 3 × 3 Latin square design with 6 pigs and three 7-d periods. All pigs were fed an N-free diet for an additional period to determine basal endogenous losses of AA. Chromic oxide was added to all diets and ileal digesta were collected according to standard procedures. In Exp. 2, 24 pigs (initial weight = 50.23 kg) were allotted to the 3 treatments using a replicated 3 × 3 Latin square design with 6 chambers (i.e., 4 pigs per chamber) and three 15-d periods. Oxygen consumption and CO2 and CH4 productions were measured during fed and fasting states and fecal and urine samples were collected. In both experiments, pigs were allowed ad libitum access to feed and water. Results indicated that there were no differences among watering options for SID of AA, feed intake, total and fasting heat production, ATTD of DM and GE, or NE in diet. In conclusion, different watering options did not affect the digestibility of AA, DM, and GE and concentration of NE in a corn-soybean meal diet fed to growing pigs.
241 Towards More Sustainable Use of Trace Elements in Pig and Poultry Feeding
Authors: Dourmad Jean-Yves , Gourlez Emma , De Quelen Francine , Narcy Agnes
Published: September 2022

Copper and zinc are essential trace elements, which play an important role in a large number of biological functions, including immunity and protection from oxidative stress. When supplied at pharmacological level, they may improve gut health and animal performance, especially during stressful periods. However, because of their low retention, most of the Cu and Zn ingested is excreted, contributing to harmful environmental impacts, such as accumulation in soils and water ecosystems, and toxicity to soil microorganisms and plants. A high level of Zn in feed may also contribute to the development of antibiotic resistance. Finally, Cu and Zn are limited natural resources that should be preserved and better recycled. To find a compromise between the positive and negative effects of Cu and Zn, we need a holistic approach considering animal performance and health, risk of microbial resistance, and risk for the environment. In that perspective, reducing dietary Cu and Zn supplies whilst maintaining satisfactory animal performance appears the most effective approach. However, to safely reduce Cu and Zn supplies, their requirements should be better evaluated and the dietary factors and mechanisms that significantly affect their bioavailability better understood. Improved manure management is another way to better control the risk of soil contamination, by concentrating these elements in organic fertilizers that might be transferred to regions with soil deficiency. In the recent years, the EU regulation on Cu and Zn content of animal feed and organic fertilizers played a major role in reducing their utilization in pig and poultry. For instance in pigs, compared to before 2003, Zn and Cu excretion was reduced by 65% (from 80 to 30 g/pig) and 80% (from 38 to 8 g/pig), respectively, as well as their concentration in excreta (from 2500 to 1000 mg Zn /kg DM ppm and from 1000 to 250 mg Cu /kg DM).
245 Preparing for a low Zinc World a new Paradigm for Feeding Piglet
Authors: Langeoire Gilles
Published: September 2022

Since many years in Western Europe a general trend pushes the consumers demand toward a meat production clear from antibacterial residue. A ban of antibiotic as animal growth promoter started in 2006. Developed in Denmark then in many other pig producing countries, the use of high level of zinc oxide was considered as the solution to limit antibiotics and efficient against the post weaning diarrheas. In France and in the Netherlands, very quickly the most negative consequence of the excreted zinc on the environment and later to the outbreak of antibiotic-resistant bacteria leaded to a ban of these therapeutic level of zinc oxide. In June 2017 the EU commission, decided to ban the high level of zinc oxide in the piglet feed at weaning; the European pig producers had 5 years moratorium to apply that new regulation. Next June 2022, the European producers will have to change of paradigm: To wean piglets with limited antibiotics and zero zinc! That new approach needs to be holistic, combining the piglet breeding and the feeding management. From our experience, some points are of real importance: Mind the feed intake: before and during weaning, Improve the nutrients’ digestibility: a highly digestible protein level can limit the risk of proteolytic fermentations and limit the risk of PWD, Increase the acidification of the diet: A Low pH and a low ABC4 will lead to a better organic acid efficiency, a better protein digestibility and a lower risk of digestive dysbiosis, Taking advantage of the dietary fibre’s fermentation: an optimal level of dietary fibre will improve the gut morphology and through the NSP fermentations will improve the microbiota and the gut health status. These recommendations will finally lead to better feed performance: Higher feed intake and better piglet growth by maintaining the eubiosis around weaning through the settlement of an optimal, stable and diversified microflora.
277 Live Animal Mitochondrial Markers During the Feedlot Phase are Related to Meat Quality in Angus but not Brahman Steers
Authors: Semanchik Pier L , Wesolowski Lauren T , Simons Jessica L , Guy Chloey , Earnhardt Audrey L , Perry George A , Long Charles R , Law Dustin , Neuendorff Don A , Randel Ron D , Machado Tanner , Welsh Thomas H , White-Springer Sarah H
Published: September 2022

Mitochondrial activity correlates with meat product quality post-harvest but little is known about the relationships between live animal mitochondria and product quality at slaughter. To test the hypothesis that live animal skeletal muscle mitochondrial markers would be correlated with longissimus Warner-Bratzler shear force (WBSF) post-harvest, longissimus thoracis (LT) and trapezius (TRAP) samples were collected from Brahman and Angus steers (n = 36 per breed) during the grazing growth phase (GP) and after 120 days on feed (FP). Samples were analyzed for mitochondrial enzyme activities via colorimetry and for oxidative phosphorylation (P) and electron transfer (E) capacities via high-resolution respirometry. Relationships between mitochondrial variables and WBSF were determined using PROC CORR in SAS (v9.4). Within Angus in GP, LT mitochondrial volume density as measured by citrate synthase activity (CS) was positively correlated with WBSF (P=0.009). In FP, Angus LT intrinsic (relative to CS) P with complex I (PCI) and maximal E with complexes I and II (ECI+II) were positively correlated with WBSF (P≤0.05), while the contribution of maximal P with complexes I and II (PCI+II) to maximal E (flux control ratio, FCRPCI+II) was negatively correlated with WBSF (P=0.03). Also in FP, Angus TRAP integrative (relative to mg tissue) PCI, PCI+II, and ECI+II and FCRPCI were negatively correlated with WBSF (P≤0.02), while the FCR for electron transfer through complex II only (FCRECII) was positively correlated with WBSF (P=0.007). In Brahman, no mitochondrial markers correlated with WBSF during either GP or FP. Post-harvest meat tenderness is related to live animal skeletal muscle mitochondrial markers when evaluated close to slaughter in Angus but not in Brahman steers.
284 Gut and Skeletal Muscle Control the Effect of low Protein Diets on Feed Intake and Thermal Radiation of Broilers During Experimentally Induced Heat Stress
Authors: Sutton Julia , Habibi Mohammad , Shili Cedrick n , Beker Ali , Burch-Konda Jacob , Salak-Johnson Janeen L , Foote Andrew P , Pezeshki Adel
Published: September 2022

The objective of this study was to assess the effects of low protein diets on feed intake (FI), heat production and markers of FI and thermogenesis regulation in broilers under experimentally induced heat stress. Two-hundred-day-old broiler chicks were weight-matched and assigned into 36 pens (5-6 chicks/pen) followed by assigning them into two treatments (18 pens/treatment): 1) thermoneutral (TN), 2) heat stress (HS). Within each treatment, the pens were randomized to receive two diets (9 pens/diet): 1) normal protein (NP), 2) low protein (LP). The study lasted 6 weeks with 2 weeks of acclimation and 4 weeks of data collection. On week 6, birds were euthanized, and blood and tissue samples collected. All data were analyzed with either GLM or mixed procedure (SPSS). The student’s t-test was used to separate means between NP and LP diets within each treatment. There was no difference in average daily gain between NP and LP diets in the TN group, but LP decreased that during HS (P< 0.05). In TN condition, LP tended to increase the average daily feed intake (ADFI) compared to NP (P< 0.1), while during HS, LP was not different from NP in terms of ADFI (P>0.05). In TN condition, LP had a higher thermal radiation than NP, but LP had less thermal radiation than NP during HS (P< 0.05). In support of ADFI data, LP had a greater ghrelin transcript in the duodenum than NP in TN condition (P< 0.05). However, during HS, LP tended to decrease the plasma ghrelin concentration compared with NP (P< 0.1). Unlike TN condition, LP had a decreased muscle sirtuin and cytochrome c oxidase transcript than NP during HS (P< 0.05). Our data provide evidence that low protein diets mitigate the negative outcome of heat stress by reducing feed intake and heat production, which are regulated through genes expressed in the gut and skeletal muscle.
317 Importance and Difficulty of Measuring Complete Greenhouse gas Flux from Diverse Beef Production Systems
Authors: Erickson Galen E , Watson Andrea K , Suyker Andy , Xiong Yijie , Okalebo Jane
Published: September 2022

Cattle naturally respire CO2 from energy and rumen metabolism, and produce enteric CH4 from rumen fermentation. In addition, N2O is produced from soils used for agricultural production following precipitation events. These three gases need to be more accurately quantified in beef production systems to model greenhouse gas (GHG) flux and establish effective mitigation strategies. Most models assume CO2 respiration equals carbon uptake by soil when cattle are fed harvested feeds or during grazing. Therefore, CH4 or N2O release is the net contribution from beef production, while ignoring respired CO2. Recent evidence suggests carbon uptake in soils within grazing systems may offset much of the GHG emissions during beef production. However, total flux is difficult to measure in open, extensive systems including pasture and feedlot pens. Using methods of eddy covariance, footprint modeling, and satellite GPS data on cattle location during grazing, we have estimated CO2 and CH4 production from grazing cattle independent of the pasture (soil and plant) to get accurate fluxes. Regardless of whether the beef industry is already net zero, focus on mitigating enteric methane production is warranted. Three primary methods are used for evaluating CH4: in vitro techniques, calorimetry head boxes, or pen chambers. The most robust system for quantification of enteric methane is pen chambers, which allows for cattle performance to be evaluated simultaneously. Many new additives are being evaluated, but not yet approved for use in food animals. Use of pen-based chambers has a limitation with large numbers of animals that cannot enter the food chain. More focus is required to find suitable methane mitigation strategies from novel feed additives and evaluate changes in productivity and ensuring no residues. Whenever possible, increasing speed of approval for those additives that are effective and pose no risk for food safety will be critical for ruminant production.
330 Developing a Leaky gut Model in Growing Holstein Heifers Using Feed Restriction Followed by Alimentation to a High Concentrate Diet
Authors: Carter Jeffrey N , Linneen Sara K , Baxter Nielson , Shields Jacob , Augspurger Nathan , Baumgard Lance H
Published: September 2022

The objective of this study was to determine if feed restriction (FR) followed by feeding a high concentrate (HC) diet would induce leaky gut syndrome (LGS) in cattle. Changes in circulatory and fecal biomarkers were utilized to assess LGS. Individually penned Holstein heifers (n=16; BW=343.2 ± 3.2 kg) were used in a completely randomized design with animal as the experimental unit. Cattle were fed a forage-based diet (71.0% hay, 12.0% cracked corn, 17.0% DDGS) twice daily ad libitum from day 0-14; from day 15-17, the daily ration was restricted by 60%. One of two HC diets (n=8 each) were fed ad libitum from day 18-30: HC75=17.0% hay, 70.0% cracked corn, 13.0% DDGS; HC65=26.5% hay, 60.0% cracked corn, 13.5% DDGS. Blood and fecal samples were collected prior to a.m. feed delivery (d -1, 0, 14, 15, 18, 20, 24, 30) and analyzed for serum amyloid-A (SAA), haptoglobin (Hp), lipopolysaccharide-binding protein (LBP), fecal lactoferrin, and fecal pH. Variables were analyzed using a mixed model with repeated measures; study day, treatment and the interaction were fixed effects. Following FR, SAA was significantly increased from day 14 to 24 (27,406.20 ± 8,917.00 ng/mL; P = 0.046). Similarly, LBP was significantly increased from day 14 to 20 (353.71 ± 44.40 ng/mL; P < 0.0001). Fecal lactoferrin increased significantly from day 18 to 20 (293.9 ± 57.54 ng/g; P = 0.0001). Fecal pH decreased significantly (1.48 ± 0.09; P < 0.0001) from day 14 to 30 and from day 18 to 30 (1.57 ± 0.08; P < 0.0001) reaching its nadir on day 30 (5.35). No meaningful changes were observed for Hp. Based on these data, FR followed by feeding a HC diet effectively experimentally induced LGS as indicated by observed changes in SAA, LBP, fecal lactoferrin and fecal pH.
352 Awardee Talk: Opportunities for Antioxidants and Plant-Derived Polyphenols to Improve Ruminant Health and Productivity
Authors: Dunshea Frank R
Published: September 2022

Plants have been used throughout history for their medicinal properties. This use has often focused on human health but plants have also been applied in animal health management and methane mitigation. Recent interest has focused on the extraction and concentration of plant bioactives for use as dietary additives, in particular as essential oils, polyphenols or antioxidants. Recent research has demonstrated that dietary antioxidants can reduce the impact of heat stress (HS) and other stressors on oxidative stress (OS). However, delivery of antioxidant supplements in extensive grazing systems is problematic and so efforts have been directed at providing antioxidant activity using forage crops high in antioxidants and polyphenols. Polyphenols are a group of compounds with antioxidant properties that can be found in various parts of plants including seeds, roots, leaves and flowers. Polyphenols have anti-inflammatory and immunomodulatory properties that prevent OS by reducing production of reactive oxygen species. For example, sugar cane-derived polyphenols reduce OS and improve growth performance in chickens. Also, polyphenols can act as hormones and growth regulators and enzyme modulators. The aim of this review is to discuss the effects of dietary antioxidants on HS in ruminants and the potential of plant-derived polyphenols to deliver similar benefits.
338 The Impact of an Aspergillus Oryzae Prebiotic on Mineral Bioavailability in Multiparous Beef Cows Supplemented with Vitaferm Concept-aid
Authors: Podversich Federico , Schulmeister Tessa M , Tarnonsky Federico , Alfaro Gastón , da Silva Gleise Medeiros , de Martinez Juan Jesus Vargas , Maderal Araceli , Gonella Angela M , Ipharraguerre Ignacio R , DiLorenzo Nicolas
Published: September 2022

This study aimed to evaluate the effect of supplementation with an Aspergillus oryzae prebiotic (AOP) fed from ~30 d pre-partum until 30 d post-partum, on mineral concentrations in blood, liver, colostrum, and milk of multiparous beef cows. Thirty pregnant Angus crossbred cows were offered ad libitum Bermuda grass hay (Cynodon dactylon) plus a Vitaferm Concept-Aid (Biozyme Inc., St Joseph, MO) supplement at a rate of 112 g, containing (AOP; n = 15) or not (CTL; n = 15) an AOP. The treatments were delivered individually with a dried distillers grains-based premix at 454 g/d using an automated feeder (C-lock Inc, Rapid City, SD). For a minimum of 60 days prior to the expected calving date, the cows did not receive any mineral supplementation. Approximately 30 days prior to calving, right before supplementation began, blood and liver samples were collected, and mineral concentrations were used as a baseline. At calving (d 0) colostrum and blood samples were collected. Blood sampling, liver biopsies and milk collections were performed within one week after calving (d 7), and 30 days post-partum (d 30). All samples were analyzed to determine mineral concentration of P, Ca, Mg, Co, Cu, Fe, Zn, Mo, Mn, and Se. Concentrations of most micro minerals ranged from marginally adequate to deficient, with small improvement over time. Cows fed AOP had 11 and 14% lesser P and Se concentrations in serum, respectively (P < 0.05). Conversely, cows fed AOP had greater concentrations of Mn concentration in milk by 34% (P ≤ 0.05), and greater Cu in milk by 74% on day 7 (P < 0.05). Feeding AOP did not affect (P > 0.10) the mineral concentrations in liver nor in colostrum. In conclusion, feeding AOP may affect mineral bioavailability in beef cows as evidenced by changes in milk mineral concentrations.
349 Dietary Zinc and Ractopamine Elicit Changes in Gene Expression of Zinc Transporters in the Muscle of Finishing Beef Steers
Authors: Deters Erin L , Rients Emma L , Carmichael Remy , Genther-Schroeder Olivia N , Hansen Stephanie L
Published: September 2022

Twenty-four Angus cross steers (467 ± 13 kg) were used to assess the effects of supplemental Zn and ractopamine (RAC; Actogain, Zoetis) on muscle gene expression. Steers were housed in pens (6 steers/pen) with GrowSafe bunks and randomly assigned to treatments (6 steers/treatment) which included 0 (CON), 60 (LO), 120 (MED), or 180 (HI) mg supplemental Zn (Availa-Zn, Zinpro)/kg dry matter. Dietary Zn treatments were initiated on d 0 and RAC supplementation (300 mg/steer/d) began on d 53. Blood and muscle (longissimus thoracis) samples were collected from all steers on d -4, 48, and 67. Plasma Zn concentrations were determined via inductively coupled plasma-mass spectrometry and muscle gene expression was determined via the Fluidigm Biomark HD system. Data were analyzed using ProcMixed of SAS (fixed effect = treatment; experimental unit = steer); treatments were compared using orthogonal linear and quadratic contrast statements. The LO treatment was removed from gene expression analyses due to poor reads. There was a tendency for a quadratic effect on d 48 and 67 plasma Zn (P = 0.10) where plasma was greater in Zn-supplemented animals than CON. Minimal effects of Zn supplementation were observed on muscle gene expression prior to the start of RAC. However, 14 d after the start of RAC, the expression of several genes involved in Zn storage and transport (MT1A, SLC39A7, SLC39A8, SLC39A9, SLC39A10, SLC39A13) linearly decreased with increasing Zn supplementation (P ≤ 0.08). These effects were mainly driven by an increase in gene expression for CON steers, suggesting RAC influences intracellular Zn trafficking or demand. Several of these transporters are located on organelles responsible for Zn-dependent processes like protein synthesis and metalation of enzymes. Therefore, increasing Zn supplementation prior to RAC feeding may support beta-agonist induced muscle growth in beef steers.
345 Evaluation of the Effects of Hempseed Cake on Ruminal Fermentation Parameters, Nutrient Digestibility, Nutrient Flow, and Nitrogen Balance in Finishing Steers
Authors: Winders Thomas , Neville Bryan W , Swanson Kendall C
Published: September 2022

There is interest in feeding industrial hemp production byproducts to livestock, but little is known about the digestibility and ruminal fermentation parameters associated with this feedstuff. A nutrient balance experiment using crossbred steers (n = 5; initial BW = 542 kg, SD = 40 kg) in a Youden square design was conducted to evaluate the effects of feeding hempseed cake (HEMP) or dried corn distillers grains plus solubles [DDGS; each included at 20% of diet dry matter (DM) in respective treatments] in comparison with a dry-rolled corn-based negative control treatment (CON) on ruminal fermentation parameters, nutrient digestibility, nutrient flow and nitrogen (N) balance. Organic matter (OM) tended (P = 0.07) to increase and OM total tract apparent digestibility decreased (P = 0.03) in steers fed the HEMP diet compared with steers fed the DDGS and CON diets. Total tract apparent N digestibility was greatest (P < 0.01) in steers fed the HEMP diet, while total tract apparent digestibility in all other nutrients was not influenced (P ≥ 0.13) by treatment. Furthermore, apparent ruminal digestibility of OM was greatest (P < 0.01) in steers fed the HEMP or CON diets, and neutral detergent fiber, acid detergent fiber (ADF), and true ruminal digestibility of N was greatest (P ≤ 0.04) in steers fed the HEMP diet. Ruminal total amino acid degradation and total ruminal VFA concentration was greatest (P < 0.01) in steers fed the HEMP diet. A treatment by hour interaction (P = 0.01) was observed for ruminal ammonia concentration. Nitrogen retention was greatest (P < 0.01) in steers fed the HEMP diet, suggesting that feeding hempseed cake improved utilization of N. These results suggest that although ruminal digestibility of all nutrients is greater in steers fed the HEMP diet, greater ADF concentration in hempseed cake negatively influences total tract apparent OM digestibility when fed to finishing steers.
368 Effects of Rumen Fermentation Parameters and Microbiota of Sanhe Heifers from Different Altitude Regions
Authors: Xinyu Zhang , Li Shengli
Published: September 2022

The rumen microbiome has an important role in providing nutrition to ruminants, which is linked to feed efficiency and environmental adaptability of ruminants. However, there is no report about the influence of different altitude regions on rumen fermentation parameters and microbiota of Sanhe cattles. In this study, 20 ruminal fluid samples of Sanhe heifers were collected from Hulunbuir City, Inner Mongolia Autonomous Region (119°57 'E, 47°17' N; about 700 m altitude, LAL) and Lhasa City, Tibet Autonomous Region (91°06'E, 29°36'N; about 3 750 m altitude, HAL), and were analyzed by gas chromatography and high-throughput sequencing to determine the rumen fermentation parameters and 16SrRNA gene. The results showed that the acetic acid/propionic acid of the high-altitude group was significantly reduced (P < 0.01), but there were no significant differences in other volatile fatty acids, rumen pH, and ammonia nitrogen (P > 0.05). The composition of the rumen bacteria of the Sanhe heifers in the high-altitude group at the phylum level, high altitude significantly reduced the relative abundance of Actinomycetes (P < 0.05), and significantly increased the relative abundance of Spirillum (P < 0.05), but had no significant effect on the relative abundance of Bacteroides, Firmicutes and Firmicutes (P > 0.05). At the genus level, Rikenellaceae_RC9_gut and Ruminococcaceae_UCG-010 increased significantly (P < 0.05); Ruminococcus_1 (P < 0.05), Olsenella (P < 0.05), and Pseudobutyrivibrio (P < 0.05) decreased significantly. Ruminococcaceae_NK4A214 and Ruminococcus_2 have a downward trend (0.05 ≤ P < 0.10). The results of this study revealed that different altitude regions influenced the microbiota composition and fermentation function of the Sanhe heifers rumen, which can provide some new insights in the mechanism of Sanhe heifers adapting to high altitude and provide a theoretical basis for the nutritional regulation of Sanhe cattle in high-altitude areas.
371 Influence of Breeding Season Lameness on Reproductive Performance in Meat Goat Does
Authors: Browning Richard , Alghamdi Ahmad , Leite-Browning Maria L
Published: September 2022

Over four years, 564 performance records from 235 does were processed to determine if lameness during the breeding season affected reproductive outcomes in meat goats. Lameness cases were recorded during routine daily herd wellness checks and treated within a short time after diagnosis. Does were bred between September and January. Kids were weaned at 3 mo of age. Fall (September-November) and winter (December-February) records were used to classify does each year as having experienced lameness (LAME) or no recorded lameness case (NOLC) by season. In the fall (F) there were 396 NOLC does and 168 LAME does. Spring kidding rates were greater (P < 0.05) for NOLC-F than for LAME-F (77.1 ± 4.5% vs. 67.9 ± 6.1%). Whole-herd litter size at kidding was greater (P < 0.05) for NOLC-F than for LAME-F (1.18 vs. 1.02 ± 0.1 kids/doe). Summer weaning rates tended to differ (P = 0.08) between the fall lameness groups (NOLC = 68 ± 3.3%; LAME = 59.5 ± 4.6%). Whole-herd litter size at weaning was greater (P < 0.01) for NOLC-F than for LAME-F (0.97 ± 0.05 vs. 0.78 ± 0.06 kids). In the winter (W) there were 473 NOLC does and 87 LAME does. Spring kidding rates were greater (P < 0.01) for NOLC-W than for LAME-W (77.6 ± 4.1% vs. 58.6 ± 7.5%). Whole-herd litter size at kidding was greater (P < 0.01) for NOLC-W than for LAME-W (1.17 vs. 0.9 ± 0.09 kids). Summer weaning rates was higher (P < 0.01) for NOLC-W than for LAME-W (68.5 ± 3.2% vs. 53.0 ± 5.9%). Whole-herd litter size at weaning was higher (P = 0.01) for NOLC-W than for LAME-W (0.95 ± 0.05 vs. 0.73 ± 0.08 kids). Results suggest that lameness in does during the breeding season may negatively impact reproductive outcomes.
211 Overcoming the Growth Deficits Programmed by Maternofetal Stress
Authors: Yates Dustin T
Published: September 2022

Prolonged maternofetal stress stunts placental development and causes fetal programming that reduces fetal growth and birthweight. Low birthweight due to intrauterine growth restriction (IUGR) of the fetus increases perinatal mortality. More commonly, however, it results in lifelong impairment of muscle growth capacity and metabolic function. In humans, low birthweight increases risk for obesity, diabetes, and other metabolic disorders by an estimated 18-fold. Similarly, low birthweight livestock exhibit greater early death loss, poor growth efficiency, and lower-quality carcasses at harvest. These animals manifest poor feed-to-gain ratios, less lean mass, and greater fat deposition. Together, these outcomes increase production costs, decrease value, and reduce the amount of meat produced per animal. The fetal programming mechanisms linking stress induced IUGR to impaired postnatal growth and metabolic efficiency are largely unknown. However, recent findings in IUGR fetal and neonatal lambs produced experimentally by maternal heat stress and maternofetal inflammation (and pair-fed controls) indicated skeletal muscle-centric programming of adrenergic and inflammatory pathways. Specifically, studies found reduced β2 adrenergic tone and enriched inflammatory signaling pathways. These changes coincided with intrinsic myoblast dysfunction, reduced muscle fiber hypertrophy, and impaired skeletal muscle glucose metabolism. Additionally, IUGR fetal and neonatal lambs exhibited impaired β cell function that may also be associated with adrenergic and inflammatory programming. Subsequent studies have investigated these mechanisms as potential therapeutic targets for interventions and treatments, which is a fundamental step in developing strategies to improve outcomes in low birthweight humans and livestock.
212 Use of Vitamin A on Developmental Studies in Ruminant Animals
Authors: Ladeira Marcio M , Junior Jose Maria Oliveira
Published: September 2022

Adipogenesis of intramuscular fat tissue in ruminant animals occurs from late pregnancy to first months of age. Therefore, the potential of intramuscular fat (IMF) deposition lasts from the fetal phase until weaning. This crucial period is known as the marbling window. Marbling is stablished by both hyperplasia and hypertrophy processes, and this attribute can be modulated by a strategic nutrient plan or bioactive compounds. Some studies showed that the angiogenesis process has a specific relationship, spatially and temporally, associated with adipogenesis. Adipose tissue is vastly vascularized with capillaries surrounding each adipocyte and this fact turns angiogenesis a target for manipulation, due to pericytes in the blood vessel’s cell wall differentiating into pre-adipocytes and adipocytes. Thus, the manipulation of the processes related to IMF deposition have been studied and the active form of vitamin A (retinoic acid) have been demonstrated to be a modulator of the key genes expression. However, there are still some remaining questions concerning adequate vitamin A dosage and its best administration time point. In Korean native cattle, they found that late pregnancy vitamin A supplementation increased, in the progeny, birth weight and upregulated the expression of genes related to preadipocyte and muscle development. When they supplemented vitamin A via oral to newborn calves, they observed an improvement in calf performance and upregulation in the expression of pre-adipogenic and myogenic genes. In research conducted in the United States using Angus cattle, it was found that neonatal vitamin A injections, at birth and at 30 d of age, promoted calf and muscle growth and IMF development in beef cattle. In the studies mentioned above were observed upregulation in myogenic, angiogenic and adipogenic genes, and also an increase in the pre-adipocytes formation. In our recent study in Brazil, using just one vitamin A injection at birth in crossbred beef cattle we found an increase in intramuscular fat deposition and upregulation in genes involved in angiogenesis and lipogenesis. In summary, through oral vitamin A supplementation during the gestational period or its oral supplementation or injection during the neonatal period, it is possible to upregulate expression of key genes of several biological processes (myogenesis, angiogenesis, adipogenesis and lipogenesis) and increase IMF deposition. Further research is needed to confirm if the vitamin A injection in pregnant cows results in similar or better outcomes in the progeny and the best dosages recommendations in injected or oral supplementation in newborn calves.
PSXII-1 CNV and Cnvr Detection from High-Density SNP Genotyping in Holstein Cattle
Authors: Ladeira Giovanni C , Pinedo Pablo J , Santos Jose E P , Thatcher William W , Rezende Fernanda M
Published: September 2022

Copy number variation (CNV) represents an important source of genetic variation complementary to single nucleotide polymorphism (SNP) and provides valuable insights into the genetic architecture of complex traits in humans and livestock animals. However, many factors affect CNV detection, including sample size. Previous studies in Holstein cattle have only used hundreds of individuals. Therefore, in the present study, CNVs were identified from high-density genotype array data in 3,529 Holstein cows from 16 herds located in 7 U.S. states. CNVs were derived from 546,802 autosomal SNP markers with MAF > 0.05 and call rate > 0.90 using the intensity signals at each SNP position in a hidden Markov model implemented in PennCNV software. The log R ratio (LRR) values were corrected based on the guanine-cytosine content in the genomic regions located 500 kb upstream and downstream of each marker. After detection, CNVs presenting LRR ≤ 0.30, B allele frequency drift < 0.01, waviness factor ≤ 0.05, number of SNPs > 10 and length > 1 kb were merged into CNV regions (CNVR) using CNVRanger. A total of 1,881 non-redundant CNV events spanning the entire genome were identified in 1,771 cows, with a mean of 10 CNVs per individual and ranging from 1 to 27. The highest percentage of CNV calls was located on BTA7 (16%), while only 9 CNVs were identified on BTA9. The CNV calls were grouped into 685 CNVRs covering 3.07% of the bovine autosomal genome. The number of CNVRs with copy loss and gain were 356 and 310, and both types were observed in 19 regions. The chromosomal distribution of CNVR revealed that BTA7 harbors 38 CNVRs, while only 2 were detected on BTA28. These results will support further research on the contribution of CNVs and CNVRs to the genetic architecture of complex traits in Holstein cattle.