bluuebunny/crossref_metadata_2025 huggingface dataset:
PSIII-7 7&7 Synch improved pregnancy rates in beef cows experiencing estrus over 24 h before fixed-time insemination
Authors: Havelka Garrett , Baumgaertner Friederike , Bochantin Kerri A , Hurlbert Jennifer L , Long Timothy , Wieland Cody , Sedivec Kevin K , Dahlen Carl R
Published: May 2024

Our objectives were to compare estrus response and pregnancy rates between two different estrus synchronization protocols and between cows that experienced estrus more than 24 h before appointment breeding and those that experienced estrus less than 24 h before breeding. Over each of 2 yr, postpartum beef cows (n = 1,108) from two different locations were ranked by days postpartum and randomly selected to receive either; 1) 7-d CO-Synch + CIDR (CO-Synch, n = 547), or; 2) 7 & 7 Synch (7&7, n = 561). For the CO-Synch treatment, cows received a controlled internal drug release insert (CIDR; 1.38g progesterone) and 100 µg gonadotropin-releasing hormone (GnRH) i.m., followed in 7 d by CIDR removal and 25 mg prostaglandin F2alpha (PGF) i.m., followed in 60 to 66 h with AI and 100 µg GnRH i.m. For the 7&7 Synch protocol, cows received a CIDR (1.38g progesterone) and 25 mg PGF i.m., followed in 7 d by 100 µg GnRH i.m., followed in 7 d by CIDR removal and 25 mg PGF i.m., followed in 60 to 66 h with AI and 100 µg GnRH i.m. Heat detection patches were applied at the time of CIDR removal to determine estrus response by the time of AI, with cows having patches ≥ 50% activated defined as being in estrus and cows with patches < 50% activated defined as not experiencing estrus. In yr 2, an additional heat detection was performed 24 h before breeding, at which time cows with ≥ 50% activated heat detection patches were defined as having an early estrus (i.e., estrus more than 24 h before breeding) and cows with activated patches first observed at the time of AI were defined as having an on-time estrus. Pregnancy status was determined via transrectal ultrasonography 35 d after AI. Data were analyzed using the GLIMMIX procedure of SAS. As expected, cows in the 7&7 treatment had greater (P ≤ 0.005) estrus response and pregnancy rates than those in the CO-Synch treatment (83% vs. 62% and 65% vs. 55%, respectively). The proportion of cows experiencing early estrus was similar (P > 0.60) between treatments (20.4 and 22.9 for Co-Synch and 7&7, respectively). Interestingly, pregnancy rate was impacted by a treatment × estrus timing interaction (P = 0.04), where cows in the Co-Synch treatment that experienced an early estrus (52.9%) had reduced pregnancy rates compared with 7&7 cows that experienced early estrus (74.0%), Co-Synch cows that experienced on-time estrus (73.7%) and 7&7 cows that experienced on-time estrus (70.5%). Our results indicate the 7&7 Synch protocol can effectively increase pregnancy rates to fixed-time AI, and that pregnancy rates of cows experiencing early estrus are influenced by synchronization protocol.
PSIII-10 Impact of late gestation vitamin A and D injection on offspring growth and immune parameters in piglets
Authors: Yankocy Samantha , Loughlin Laura , Walker Rachel , Hines Elizabeth A
Published: May 2024

Supranutritional use of vitamins may have an impact on mortality rates of sows and piglets. Specifically, injection of vitamin A, and vitamin A and D (VitAD) has improved subsequent preweaning mortality when given to sows after weaning and improved immune response in offspring when administered to cattle in late gestation. However, little work has been conducted to investigate developmental impacts of gestational vitamin supplementation in piglets that may impact immune development. To investigate the relationship of VitAD supplementation on offspring development, this study evaluated sows (n = 20) injected intramuscularly with VitAD (312,000 IU vitamin A, 52,500 IU vitamin D) or a saline at d 85 of gestation. Effect of VitAD on performance and immune development was assessed from birth through wk 5 post weaning. Starting at birth (n = 95 VitAD, n = 114 control) piglet serum was collected weekly during the 4 wk lactation period, and a subset of piglets were bled weekly through the nursery. Blood was analyzed for retinol concentrations from birth through 5 wk post weaning and immune parameters via complete blood count analysis for 5 wk post weaning. Milk samples were also collected weekly during lactation and assessed for retinol concentrations via liquid chromatography. Data were assessed via a mixed procedure (SAS 9.4) with sow as random and treatment as fixed variables. Covariate of wean age was assessed for post weaning growth and of sampling time for retinol and CBC analysis. At farrowing, differences in birth weights were not observed (P ≥ 0.69). Through the lactation phase, control piglets had a tendency for increased average daily gain (P ≥ 0.07); however, no differences (P ≥ 0.27) were observed in piglet growth performance during the nursery phase. Blood and immune parameters assessed were not different across treatments from birth through 9 wk of age. Circulating retinol concentrations were greater in the control group, (P ≤ 0.05) at 15, 22, and 28 d of age, compared with VitAD. Milk retinol concentrations were increased in the VitAD group on d 8 of life, (P ≤ 0.05), but not at any other time during lactation. These results suggest that supplementation of VitAD on d 85 of gestation in sows impacts the retinol concentrations in milk for a limited period, but not growth or circulating retinol and immune parameters in piglets at any age. Based on these data, efficacy of supranutritional injection of VitAD may be timing specific and limited to benefiting the litter during lactation. Further research is needed to assess specificity of timing and impacts on piglet health and survival.
PSV-8 Development of genetically engineered microbes as probiotics to enhance ruminant productivity
Authors: Doan Tien , Neujahr Alison C , Fernando Samodha C
Published: May 2024

Alternatives to antibiotics (especially metaphylactic use of antibiotics in livestock) are critically needed to ensure animal and human health while meeting the increasing food demand of the growing human population. One of the proposed alternatives to antibiotic use that is gaining momentum is the use of probiotics or direct-fed microbials (DFMs), which are live microbes that have specialized functions that improve gastrointestinal health and performance. However, to date, most probiotics or DFMs tested as alternative to antibiotics to reduce pathogen colonization have shown limited effectiveness with inconsistent results. This is due to the fact that only, generally accepted as safe (GRAS) bacterial strains are being used as DFMs or probiotics in the animal industry. However, metagenome studies have clearly shown the presence of unique biosynthetic gene clusters and other beneficial genes within gut environments in livestock species in non-GRAS organisms. As such, with advances in gene editing techniques, tools are now available to strategically integrate beneficial genes found in non-GRAS approved microbial strains into GRAS approved strains to develop genetically engineered microbes with beneficial functions. As a first step towards developing genetically engineered microbes to improve animal health and performance, we engineered a biosynthetic gene cassette identified from rumen microbes into GRAS approved Bacillus strains. We utilized chasis-independent recombinase-assisted genome engineering (CRAGE) and random transposon mutagenesis to insert biosynthetic genes into GRAS approved strains. Furthermore, we performed functional screening experiments to identify strains containing the engineered gene cassette and confirmed using sequencing. This approach can be used to engineer beneficial genes and generate personalized probiotics to improve animal health and productivity.
PSV-9 Effects of increasing amounts of high-oleic or conventional soybeans in diets fed to mid-lactation dairy cows on measures of dry matter intake and lactation
Authors: Hagemann Tiffany , Petzel Emily A , Bailey Eric , Brake Derek W
Published: May 2024

The objective of the study was to determine effects of increasing amounts of conventional (CONV) or high-oleic (HO) soybean in diets fed to mid-lactation dairy cows on dry matter intake (DMI) and performance. Rumen and duodenally cannulated cows (n = 8) were split into two groups and placed in a split-plot design. The whole plot factor was type of soybean (CONV vs. HO) and was provided to cows in a crossover arrangement so that each cow was provided both types of soybeans throughout the experiment. The subplot factor was amount of soybeans (0, 4, 8, 12%). Each group of cows receiving the same type of soybean were placed in a 4 x 4 Latin square with treatment sequences balanced for carryover effects. Diets were formulated to contain 18.5% crude protein and to slightly exceed requirements for ruminally degradable protein. Additions of soybeans replaced soybean meal and soybean hulls so that diets provided similar amounts of soy-based protein and fiber. During the last 4 d of each 14-d period, spot samples of feed, orts, and milk were collected together with measures of milk production and feed intake. Data were analyzed using the MIXED procedure of SAS. There were no interactions of soybean type and amount on lactation or DMI except for measures of milkfat, milk energy concentration and milkfat yield. Increasing amounts of HO resulted in a quadratic response in milkfat and energy concentration together with measures of milkfat yield. Specifically, these measures were greater (P ≤ 0.02) when cows were fed diets containing 4 and 8% HO compared with diets containing 0 or 12% HO; increasing amounts of CONV had no impact (P ≥ 0.32) on milkfat and energy concentration or milkfat yield. Measures of milk yield were not affected by type or amount of soybean (P ≥ 0.54), but measures of energy corrected milk yield (ECM) tended to respond differently to increasing amounts of soybean from either CONV or HO (P = 0.07). Interestingly, ECM responded quadratically (P = 0.02) to increasing amounts of HO but not to increasing amounts of CONV (P ≥ 0.58). Overall, however, ECM tended (P = 0.06) to be slightly greater with HO compared with CONV (42.5 vs. 41.1 kg/d). Yet, DMI was also greater (P ≤ 0.01) with HO compared with CONV (26.6 vs. 24.4 kg/d). Differences in DMI, therefore, resulted in a tendency (P = 0.07) for greater efficiency of ECM production when cows were fed CONV vs. HO. Overall, treatments had no effect on measures of milk protein, urea-nitrogen, solids-not-fat or lactose concentrations or yields. These data seem to indicate that performance responses among lactating cows to increasing amounts of HO are dynamic but that responses to CONV are not.
PSV-11 In vitro screening of selected compounds to reduce ruminal methane production
Authors: Assumpcao Alice H Peres , Mantovani Hilario C , Zhu-Barker Xia
Published: May 2024

Methane is a natural product of rumen fermentation and emissions from ruminant livestock represent a major environmental concern. Methane is not only a potent greenhouse gas but also represents a loss of energy efficiency for the host. The objective of this study was to perform in vitro screening of a range of compounds with potential anti-methanogenic activity, including polyphenols, flavonoids, fatty acids, amino acids, and salts. We aimed to select compounds conferring up to a 20% reduction in CH4 for further investigations. The substances tested included carvacrol, coumaric acid, coumarin, flavanone, gallic acid, glycerol monolaurate (GML), glycine, methylene blue, naringin, quercetin, quinic acid, resorcinol, rutin, tannic acid, vanillic acid, and zinc acetate. These substances varied in their mechanisms of action and were selected based on known antimicrobial or anti-methanogenic properties. The experiment was designed as a randomized block experiment, with treatments tested in triplicates across four batches (n = 228 samples) using the same treatments and experimental conditions. Fresh rumen contents were manually collected from two rumen-fistulated lactating Holstein cows, 3 h after their morning feeding. Rumen contents were blended at a 2:1 ratio, filtered through a four-layered cheesecloth, and added to McDougall’s solution at a 2:1 ratio. Final media (9 mL) was added to a 20 mL Bellco flask containing 150 mg of total mixed ration (TMR) ground to 1 mm. Each batch also had three flasks without TMR and no treatment (blank flasks), three flasks containing only TMR without treatment (negative control), and three flasks containing TMR and treated with chloroform (positive control), resulting in a total of 19 treatments. The end-products of in vitro batch fermentations were assessed after 24 h of incubation, and samples from each flask were collected for gas composition analysis using gas chromatography. Volatile fatty acids were determined using high-performance liquid chromatography (HPLC). The data were analyzed using R Studio, and the following model was applied: yij = µ + treatmenti + batchj + ℇij. Methane production (measured in parts per million, ppm) increased when GML, naringin, and quercetin were added compared with the negative control. In contrast, the addition of carvacrol, glycine, tannic acid, and methylene blue resulted in a decrease of up to 25% in methane production. These compounds show potential to alter ruminal fermentation and mitigate methane production and will be selected for evaluation of synergistic interactions and effects on the rumen microbial communities.
PSV-12 Microbial community structure of dairy cattle is stable through oscillating crude protein inclusion
Authors: Víquez-Umana Fiorella L , Erickson Mary Grace , Zanton Geoffrey , Wattiaux Michel , Suen Garret , Mantovani Hilario C
Published: May 2024

Diet has an important role in shaping the structure of rumen microbial communities. However, little is known about the interaction between dietary crude protein (CP) level and CP feeding pattern on the rumen microbiome of dairy cows. Here, the objective was to evaluate the influence of CP level (low protein [LP], 13.8%; high protein [HP], 15.5% of dry matter [DM] basis) and CP feeding pattern (OF = oscillating, SF = static) on the composition and diversity of the rumen microbiome of lactating dairy cows using 16S rRNA gene amplicon sequencing. Rumen-cannulated Holstein cows (n = 8) in mid- to late-lactation were assigned to a 2 x 2 factorial experiment consisting of 4 experimental periods of 28 d. Each experimental period had an adaptation phase to the diet (24 d) and a sampling phase (d 25 to 28). The treatments with oscillating feeding alternated diets every 48 h to vary CP above and below the mean CP level (OF-LP = 13.8 ± 1.8%; OF-HP = 15.5 ± 1.8% CP of DM) whereas diets were constant in the static feeding (SF-LP = 13.8%; SF-HP = 15.5% CP of DM). According to the NASEM (2021) model predictions the LP diet supplied 94% of the microbial protein requirement while the HP diet exceeded (104%) requirement. Rumen samples were collected 4 h after feeding through a rumen cannula and amplicon libraries were generated targeting the V4 region of the 16S rRNA gene. The amplicon sequences were analyzed in qiime2. Sequences where trimmed based on their quality and then grouped in ASVs using DADA2. The ASVs were used to analyze the composition and diversity of the rumen microbiome in each treatment. Alpha diversity of the rumen microbiome did not change across treatments (Kruskal Wallis, P > 0.05), but Pielou’s evenness increased by 0.01 units (Kruskal Wallis, P = 0.04). These results support the hypothesis that the rumen microbiome is stable to oscillating CP feeding patterns and compensates for the changes in crude protein content in the diet. Further research is required to understand the dynamics of this compensation and what other metabolic processes in the ruminant contribute to maintaining production under an oscillating diet.
PSVI-5 Extruded blend of Nannochloropsis oculata microalgae and flaxseed and its effects on ruminal fermentation and nutrient digestion
Authors: Thorn Ross L , Drouillard James S
Published: May 2024

Omega-3 fatty acids are essential nutrients for mammals, and are required for cellular growth and synthesis of numerous cellular signaling molecules. NBO3 Technologies, LLC (Manhattan, KS) has developed an omega-3 supplement consisting of an extruded blend of flaxseed and Nannochloropsis oculata microalgae (GreatOplus; GOP). Our objective was to evaluate effects of GOP on dry matter intake (DMI), water intake (WI), ruminal metabolism, and apparent total tract nutrient disappearance in cannulated Holstein steers (n = 11; initial body weight 586.4 ± 49.7 kg). Treatments consisted of backgrounding diets (40% roughage, 60% concentrate) containing 0% (CON) or 10% GOP (dry basis). Feed and water intake were recorded using an Insentec Roughage and Water monitoring system (Hokofarm Group; Emmeloord, The Netherlands). Steers were utilized in a cross-over design with two 19-d periods. Each period consisted of a 15-d adaptation phase and a 4-d collection phase. Ruminal contents, duodenal digesta, and feces were collected at 8-h intervals for 4 d starting at 1000 h on d 16. The sampling schedule was advanced by 2 h with each subsequent sampling day, thus generating a 24-h profile at 2-h intervals post-feeding over the 4-d sampling phase. Titanium dioxide (15 g) was dispensed directly into the rumen of each steer 15 min before feeding and to estimate apparent ruminal flow and fecal excretion of nutrients. There was a Treatment X Day interaction for DMI (P < 0.001); DMI was greater for steers fed GOP some of the days during the adaptation phase compared with steers fed the control diet, but intakes were similar during the collection phase. Ruminal fluid pH, ruminal ammonia concentration, and WI were not affected by treatment (P > 0.10). As expected, ruminal outflows of total fatty acids (195.6 vs 338.1 g/d for CON and GOP, respectively) and α-linolenic acid (ALA; 1.6 vs 6.3 g/d, respectively) were greater for steers fed GOP compared with steers fed CON (P < 0.05); however, ruminal disappearance (i.e., biohydrogenation) of ALA was extensive, with only 8% and 4.7% of ALA intake exiting the rumen for CON and GOP, respectively. Apparent total tract digestion of organic matter was not impacted by diet (P > 0.20; 78.1 and 76.8% for CON and GOP, respectively). Supplementing an extruded blend of flaxseed and microalgae can effectively increase the amount of α-linolenic acid available for absorption in the small intestine, but overall recovery of dietary α-linolenic acid is relatively low due to extensive biohydrogenation by microbes within the rumen.
PSVI-1 Backgrounding and finishing systems for cattle fed corn silages and corn grains differing in amylase expression
Authors: de Monteiro Ludmila Souza , Drouillard James S
Published: May 2024

Amylase is a key enzyme involved in the hydrolysis of starch, which typically constitutes the predominant source of energy in feedlot cattle diets. Performance of cattle during the backgrounding phase can influence performance during the subsequent finishing phase. Our objective was to assess growth performance of backgrounding steers fed diets that contained combinations of corn silage (S) and steam-flaked corn (G) from hybrids with high amylase expression (Enogen corn; E; Syngenta Seeds, LLC) or common corn hybrid (C), as well as subsequent finishing performance, carcass characteristics, and liver abscess incidence when fed G produced from the same hybrids. Crossbred steers (n = 911; 306 ± 8 kg initial body weight) were assigned randomly to one of four backgrounding treatments with 12 replicates in a randomized complete block experiment using a factorial treatment arrangement. Factor 1 consisted of two corn silage hybrids (ES or CS), and factor 2 consisted of two SFC hybrids (EG or CG). In the subsequent finishing phase, animals were assigned to one of two treatments consisting of two grain hybrids (EG or CG) with 24 replicates per treatment. Backgrounding diets (dry basis) contained 20.1% flaked corn and 41.6% corn silage, and finishing diets contained 81.5% flaked corn with triticale silage as a common roughage source. There was no three-way interaction for measures of interest, and no differences among treatment combinations with respect to average daily gain (ADG) or incidence of abscessed livers (P > 0.10). Steers fed CG during the backgrounding phase ate more than steers fed EG (P = 0.04), thus leading to improved overall efficiency of steers fed EG in the backgrounding phase compared with their counterparts fed CG (P < 0.01; Table 1). Overall efficiency tended to be greater for cattle fed CG during the finishing phase (P = 0.06) compared with cattle fed EG during the finishing phase. There was a tendency for interaction between G fed in the backgrounding and G fed in the finishing phase for hot carcass weight (P = 0.07), such that steers fed the same hybrid in both phases had greater carcass weight compared with those fed different hybrids in the backgrounding and finishing phases. Type of grain fed in the backgrounding and finishing phases, but not silage, impacted overall system efficiency.
PSVI-3 Effects of dried distillers grains on performance of suckling beef calves in a creep-feeding system
Authors: De Matos Ellem Maria Almeida , De Valadares Filho Sebastião Campos , David Gabriel Santos Souza , Tropia Nathalia Veloso , de Andrade Dhones Rodrigues , da Silva Julia Travassos , Pucetti Pauliane , Andrade Cidrini Fernando Alerrandro , de Sousa Luiz Carlos Oliveira , Caton Joel S
Published: May 2024

Dried distiller’s grains (DDG) have been successfully used in beef cattle diets due to their high protein content and increasing availability around the world. However, the chemical composition of DDG varies according to the type of fermented grain and processing methods, and its increased sulfur content can compromise animal performance. There are few studies evaluating DDG in supplements for beef calves in creep-feeding systems. Hence, our objective was to assess the effects of DDG on performance of suckling beef calves in a creep-feeding system. Nellore×Red Angus male calves (n = 37), weighing 162 ± 4.06 kg at 120 d of age, along with their respective dams (n =37 Nellore cows) were used. The cow-calf pairs were randomly assigned into eight paddocks formed by Urochloa decumbens pastures. Animals were subjected to a 14-dadaptation period and an additional 108-d period for performance evaluation. All animals had access to water and mineral mixture ad libitum. Four treatments were evaluated, as follows: control (mixture mineral only), supplement without DDG, or supplements including 375 and 750 g/kg DDG [dry matter (DM) basis]. The supplements were composed of ground corn, soybean meal, urea, and DDG, planned to contain 300 g CP/kg DM, and provided daily at 7.0 g/kg body weight (BW; as fed). Treatments were assigned to experimental units (i.e., calf) in a completely randomized design. Calves were weighed at the beginning and end of the experiment, as well as every 15 d, to adjust the amount of supplement to be provided. Comparisons between treatments were performed by decomposing its sum of squares into orthogonal effects as follows: 1) control (mineral mixture only) versus supplemented calves; 2) evaluation of the linear and quadratic effects of the inclusion of DDG in the supplements. Data were analyzed using the MIXED procedure of SAS 9.4 (α = 0.05). Supplementation enhanced (P < 0.05) average daily gain (ADG) and final body weight (FBW) when compared with control. On average, ADG was increased from 0.94 kg/d to 1.08 kg/d for control and supplemented calves, respectively. On the other hand, ADG and FBW decreased linearly as the DDG inclusion in the supplement increased (P < 0.05). The differential ADG of calves that received supplements with 375 and 750 g/kg DDG compared with calves that did not receive DDG was -0.046 and -0.096 kg, respectively. It is worth emphasizing that calves fed supplements with 375 g/kg and 750 g/kg DDG had a 14% and 46% less supplement intake, respectively, than animals that were not fed DDG. Supplementing beef calves in a creep-feeding system enhances animal performance. However, the inclusion of high DDG levels in supplements decreases the performance of suckling beef calves.
PSVI-2 Economic evaluation of forage-fed vs concentrate-fed beef finishing systems
Authors: Robertson Joel , Tollefson Rebecca L , Winebold Deedra M , Deaton Claire , King Adam , Case Riley , Church Emily R , Holder Amanda
Published: May 2024

The objective of this study was to determine the economic benefit of implanting beef steers and including a beta-agonist in the finishing diet. To accomplish this, Hereford-cross steers (450 ± 15 kg) were assigned to one of three drylot pens based on initial body weight (BW) and sire so that each pen had an equal starting BW and sires were equally represented in each pen. Each drylot pen was assigned to one of three treatments: receiving a hormonal implant (IMP), consuming a beta-agonist (BAG), or receiving both of the previous treatments (AND). All steers were fed a mixed ration consisting of 30.0% rye silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement [22.0% CP, 2.90 Mcal ME/kg dry matter (DM)]. The data were analyzed in SAS v9.4. Animals were evaluated on intake, growth, and performance measures during a 45-d feeding trial. Average daily gain (ADG) and hot carcass weight differed (P < 0.05) between treatments with AND steers gaining 1.48 kg/d with a hot carcass weight of 394.8 kg, BAG steers gaining 1.28 kg/d with a hot carcass weight of 352.9 kg, and IMP steers gaining 1.26 kg/d with a hot carcass weight of 347.4 kg. The BAG treatment rendered decreased marbling scores than IMP and AND (P < 0.05). It was concluded based on carcass quality data that there was no difference in the IMP and AND treatments, though the AND treatment had greater growth rates and feed conversion rates. Results of this trial are expected to indicate at what price point it becomes economically effective to finish animals using a beta-agonist in conjunction with a hormonal implant.
PSVI-6 Metabolic potential of three novel rumen bacterial species from sheep characterized by utilizing a metagenomic-based approach
Authors: Anema Reid F , Smith Zachary K , St-Pierre Benoit
Published: May 2024

The sheep rumen microbiome contains a vast wealth of known and unknown members, whose metabolic processes impact nutrient acquisition as well as gut and overall health of the animal. Based on previous research from our group on investigating the impact of a change in diet on the composition of the rumen microbiome in lambs, further insights into the metabolic functions of novel bacterial species represented by three Operational Taxonomic Units (OTUs) were pursued. The rumen fluid samples with the greatest abundance of OTUs RA1-01223, RA1-00032, and RA1-04216 were, respectively, used as representatives for metagenomic investigations to assemble the genomes of their corresponding bacterial species. Purified microbial genomic DNA was used as a template for ‘shotgun’ sequencing with an Illumina Miseq (2 x 250) platform. Raw datasets were filtered for quality then used for contig assembly with an in-house developed set of Perl scripts, generating 64 contigs for RA1-01223 [combined total length: 2,046,349 base pairs (bp)], 118 contigs for RA1-00032 (combined total length: 3,704,255 bp), and 119 contigs for RA1-04216 (combined total length: 8,884,743 bp). After building, coding sequences were identified and annotated using RAST, with metabolic pathways of predicted enzymes constructed for each OTU of interest using KEGG pathways as a model reference. Annotated coding sequences were also screened by blastp to assign contig sets to each OTU based on their respective taxonomic affiliation; both OTU RA1-01223 and OTU RA1-00032 were found to be most closely related to Ruminococcus bili (94.8% and 86.8%, respectively), while RA1-04216 was affiliated to Succinivibrio dextrinsolvens (96.9%). As RA1-01223 and RA1-00032 were found to possess enzymes responsible for lactate metabolism, they could potentially affect susceptibility to acidosis by acting as modulators of ruminal pH or by producing lactate from starch degradation. Distinguishing features between these two OTUS included the pathway for vitamin B5 synthesis, using uracil or L-aspartate as precursors (RA1-01223), and the ability to produce ethanol as an end product of ruminal fermentation (RA1-00032). Distinguishing metabolic activities of interest for RA1-04216 included synthesis of chorismate and prephenate, which are precursors for tryptophan and phenylalanine, respectively. Together, these results contribute to a better understanding of the metabolic roles of individual microorganisms in the rumen, providing information that is crucial for creating a healthy and proactive environment that benefits the host.
PSI-3 Effect of feed and water consumption patterns during the lactation period on wean-to-estrus interval in weaned sows
Authors: Soriano Magdiel Lopez , Grohmann Caleb J , Safranski Timothy J
Published: May 2024

There is sufficient evidence that adequate feed and water consumption during the lactation period positively influences sow body condition at weaning. Optimum body condition score after the lactation period decreases sow wean-to-estrus interval and non-productive sow days and promotes sow reproductive performance in the following reproductive cycle, in general. However, feed and water intake patterns have not been extensively studied in commercial sow research; thus, the objective of this study was to determine the effect of feed and water consumption patterns in the lactation period on wean-to-estrus interval in weaned sows. This trial was conducted in a commercial sow farm located in southwestern Minnesota in March 2023. Each lactation feeder was outfitted with a MealMeter 2.0 device (PigEasy, LLC, Templeton, IA), which uses a rotating feed dispenser to release feed ad libitum at the request of each sow. In addition, the MealMeter 2.0 device utilizes sensors to track the number of times feed and water were accessed at 15-min time intervals across the entire lactation period. Average daily feed (ADF) and water accessions (ADW) were summarized for each sow during the lactation period (n = 84 sows). Root mean squared error (RMSEF and RMSEW for feed and water accessions, respectively) was calculated from the residuals of the regression between days post-farrowing and ADF and ADW for each sow and was considered a measure of variation in feed and water accessions during the lactation period. Moreover, the number of days from weaning to the first estrus was recorded and defined as the wean-to-estrus interval (WTE). Due to the distribution of WTE, sows with a WTE ≤ 5 d and WTE > 5 d were separated into a binary classifier (0 = WTE ≤ 5 d and 1 = WTE > 5 d). The relationship between each feed and water measurement and WTE class was estimated using a logistic regression model fit with R Statistical Software. Average daily feed and water accessions were negatively associated with WTE class (P- = 0.07 and 0.04, respectively; Table 1), indicating that as feed and water accessions increase, the probability of observing a WTE greater than 5 d decreases. In addition, RMSEF and RMSEW were also negatively associated with WTE class, which suggests that as the variation in each measure across the lactation period increases, the probability of observing a WTE greater than 5 d is reduced. This result was not expected and, thus, requires further investigation. Nonetheless, results from this study suggest that the mean and variation of daily feed and water accessions are associated with WTE and sufficient consumption of nutrients during the lactation period is critical to reducing the number of days to first estrus in weaned sows.
PS-1 An evaluation of sodium salicylate in the periparturient management of the sow
Authors: Olson Lauren , Weaver Eric
Published: May 2024

Mortality continues to trend higher in highly prolific sows in the U.S., with the periparturient period being the time of greatest loss (Eckberg, 2021). Sodium salicylate (NaSal) is a nonsteroidal anti-inflammatory drug (NSAID) similar to aspirin, which is used to manage pre-eclampsia-related pregnancy complications in humans (Roberge et al. 2017). The objectives of this experiment were: 1) Collect farrowing data for scoring periparturient health; and 2) Evaluate the impact of NaSal on periparturient health and inflammation. A total of 47 parity 1 and 2 females (PIC 1050) were utilized with a starting body weight (BW) of 214.3kg ± 14.7 SD. Sows were blocked by BW on d 105 gestation and parity and randomly assigned to one of two treatment groups. The treatments were: control (CON) n = 23; or treatment (TRT) n = 24. TRT consisted of NaSal (Oral-Pro, Aurora Pharmaceutical, Northfield, MN) administered via water 3 d pre-farrow to 5 d post-farrow, with a target dose of 50 mg NaSal/kg BW. At d 106 of gestation and weaning, BW, back fat (BF), and body condition by caliper (BCS) were measured. Sows were assigned a farrowing ease score of 1-4 (1 - easy to 4 - extremely difficult) based on duration, restless activity, savaging, and assistance required. Data were analyzed using the GLM procedure in SAS, with sow serving as the experimental unit and LSMeans testing for differences among means. Average farrowing duration for both groups was 335.5 min ± 144.2 SD. Farrowing ease score for all sows was assessed as a mean of 2.28 with 47% scored as difficult (Score 3 to 4). Treatment improved farrowing ease score (TRT avg: 1.9; CON avg 2.7; P < 0.01) and reduced savaging severity and frequency (TRT: 5 sows, 1 severe; CON: 8 sows, 7 severe; P < 0.05). TRT sows (24/24) successfully weaned litters compared with CON sows (20/23). All sows assigned a 1 or 2 score (25/25) weaned litters compared with sows assigned 3 or 4 (19/22). In conclusion, farrowing difficulty contributes to the need for greater care of highly prolific sows. Supplementation of NaSal during the periparturient period may improve farrowing ease and health outcomes.
PSI-5 Evaluation of EhV (surrogate for African swine fever virus) inactivation in corn- and soybean-based feed ingredients and diets at various times and temperatures during storage
Authors: Ramirez Christian , Schroeder Declan , Shurson Gerald C , Urriola Pedro E
Published: May 2024

African swine fever virus (ASFV) is a member of the nucleocytoplasmic large DNA viruses (NCLDVs) and remains stable in a variety of environments, including animal feed ingredients as shown in previous laboratory experiments and simulations. Emiliania huxleyi virus (EhV) is another member of NCLDV, which has a restricted host range limited to a species of marine algae called Emiliania huxleyi. This algal NCLDV has many similar morphological and physical characteristics to ASFV which makes it a safe and reliable surrogate for studying ASFV survival and inactivation in feed ingredient matrices in-situ under various time and temperature storage conditions. The objective of the present study was to investigate the inactivation of ASFV in various feedstuffs under a wide range of time and temperature conditions during storage using EhV as a surrogate. Corn- and soybean-based feed ingredients including corn, corn fermented protein, distiller dried grains with solubles, extruded soybean meal, high protein distiller’s grains, solvent-extracted soybean meal, soybean hulls, complete feed, and a positive control (no matrix) were inoculated with EhV (1 × 108 viruses/mL). Negative controls were inoculated with medium containing no EhV for each matrix. To assess the effects of different times and temperatures of storage, all samples were stored at temperatures of 4, 24, and 34 °C for 1, 5, 60, and 120 d. For each timepoint and temperature combination, samples were evaluated for virus presence (qPCR) and viability using a previously validated viability qPCR (v-qPCR) method. On average, we observed a 0.2 log reduction in viable viral DNA content over the 120-d period, with a 0.1 log reduction across varying temperatures. No reductions in EhV viability exceeding 1 log were detected for any matrix and the positive control at any time and temperature combination evaluated. No EhV was recovered from the negative control samples. Given that the experimental error was calculated to be within the range of 1 log, we concluded that storing EhV at 4, 24, or 34 °C for up to 120 d did not result in the inactivation of EhV in any of the ingredients, complete feed, or the control with no matrix. These results demonstrate that ASFV-like NCLDVs is extremely resilient and can maintain viability in various feed matrices during long-term storage and suggest that extending storage time alone may not be an effective mitigation practice against African swine fever virus.
PSI-9 Relationship of body condition measures and boar reproductive performance
Authors: Hedrick Hailey M , Grohmann Caleb J , Minton Amanda , Safranski Timothy J
Published: May 2024

In the swine industry, boar nutritional requirements are not well characterized; thus, boars are typically fed to maintain a specific body condition score (BCS). Assessing body condition with subjective scoring can lead to over or underfeeding, which may have repercussions on sperm production and(or) quality. There are objective tools to assess body condition in live boars, like backfat (BF) thickness measured with real-time ultrasound, the Knauer caliper, and flank-to-flank (F2F) length. The relationship of sperm production and quality with BCS has not been reported in modern genetics and modern boar studs. The purpose of this study was to evaluate the relationship of body condition measures with boar reproductive performance. Data collected in March 2023 on commercial boars (n = 147) included a BCS ranging from 2.25 to 3.5, ultrasound backfat (13.7 ± 4.37 mm) performed by a trained technician, body weight (BW; 222 ± 30.2 kg) estimated using heart girth and body length from poll to tailhead, F2F length (106.03 ± 5.94 cm) and Knauer caliper score (17.5 ± 2.37). Additional variables considered were boar genetic line, age, and collection frequency. Sperm production data (total motility, 92.1 ± 7.22%; concentration, 36.7 ± 12.10 mil/mL; ejaculate volume, 231.1 ± 73.72 mL; normal cells, 83.4 ± 11.27%) were obtained from the six collections immediately prior to body condition evaluation. Data were evaluated with the glmmTMB package of R Statistical Software using a generalized linear mixed model. There were no significant relationships between motility or ejaculate volume and boar body condition. Backfat depth was related to percentage of normal cells (P = 0.029) and inversely related to sperm concentration (P = 0.035). There was a tendency for boars with greater F2F to have greater sperm concentration (P = 0.090). Generally, the percentage of normal cells decreased with increasing BCS, though due to the low number of observations in the lower categories, only BCS 3.25 and BCS 3.5 boars were found to have a significant relationship with the trait (P = 0.004 and P = 0.022, respectively). Caliper measure was not related with any sperm parameters. While accessible tools are necessary for consistent management of boars, BF thickness measured by ultrasound was the only objective tool in this study with a significant relationship to any sperm parameters assessed. Measuring BF with ultrasound may not be practical for everyday use. More research should be done to further assess body condition measurements, objective measuring tools, and boar sperm production.
PSI-2 Daily thermoregulatory performance patterns of Duroc boars with or without electronically controlled floor cooling pads during the peak summer heat stress period
Authors: Licuan Daphne , Stewart Kara R , Hundley Jamie , Nepomuceno R J , Robins Matt , Crasto Randolph , Didion Bradley A , Kleve-Feld Michael , Sung Jung Y , Schinckel Allan P
Published: May 2024

The objective of the study was to evaluate the daily thermoregulatory pattern of Duroc boars with and without electronically controlled floor cooling pads (ECP) during the summer season in a boar stud at Scottsville, Kentucky. Thirty boars were placed in two rows of pens (2.06 x 0.66 m) of a 350 head tunnel ventilated barn and were randomly assigned to either CONTROL (n = 15; no ECP) or PAD (n = 15; 4.25 L cold water flushed when sensors reached 27°C or every 4 min, whichever occurred first, through a group of 5 pads connected to each other) treatments. Boars experienced natural seasonal heat stress (daily mean temperature = 25.7°C; hourly high temperature = 28.8°C, corresponding relative humidity = 85.4%, corresponding dew point = 26°C) during the period of 4 d wherein the ECP remained on, and flushing based on the setpoints mentioned above. Rectal temperature (RT) and respiration rate (RR) were taken at 600, 830, 1100 1330, 1600, 1830 and 2100 h daily for all 4 d. Two statistical analyses were conducted. The first was a mixed model including the fixed effects of ECP, day, time of measurement and their interactions with boar included as a random effect. Secondly, mixed model periodic regressions were fitted to the RR and RT data. Both RT and RR were impacted by ECP, day, time, and all two and three factor interactions (P < 0.001). The final periodic regression model for RR included the random effect of boar, main effect of ECP, interaction of ECP and day, single phase sine/cosine and 2-phase cosine variables, the interaction with the single 2 and 3 phase sine/cosine variables with day (P < 0.001). The periodic regression results indicate that the response of the ECP to reduce RR were consistent relative to the time of the day (mean of 57.5 breaths/min versus 18.9 breaths/min, P < 0.001) but the overall response in RR relative to time of day was variable for the four days. The final model for RT using periodic regression included the random effect of boar, ECP, single-phase sine and cosine and three-phase sine variables (P < 0.001) and interaction of single-phase sine by ECP (P = 0.001) and interaction of the three-phase sine with day. The interaction of the ECP by single phase sine interaction was due to an increase in temperature from 600 to 1330 for control boars (0.21°C) versus no change for boars on the ECP. The ECP reduced RT at all measurement times, a lesser extent from 600 to 1100 (0.31°C to 0.37°C) and greater extent from 1330 (0.59°C) and 1600 h (0.63°C) and 2100 (0.67°C). The impact of the ECP to reduce RR and RT varied from day to day with greater effects on the days with higher barn temperatures.
PSI-7 Hourly flushing rates and temperature trends for electronically controlled grouped floor cooling pads trends during the summer heat stress in a boar stud
Authors: Licuan Daphne , Stewart Kara R , Hundley Jamie , Nepomuceno R J , Robins Matt , Crasto Randolph , Didion Bradley A , Kleve-Feld Michael , Sung Jung Y , Schinckel Allan P
Published: May 2024

The objective of the study was to evaluate the flushing management trends of the electronically controlled grouped floor cooling pads (ECP) during the summer heat stress in a boar stud at Scottsville, Kentucky. Four groups of 5 ECPs connected to each other were placed in 15 boar crates (2.06 x 0.66 m) in a 350 head evaporative cooled, tunnel ventilated barn. One set of ECP (Zone 1) had temperature sensors placed on the 5th pad which triggers flushing of 4.25 L cold water (over 80 sec interval) when sensors reached 27°C. The other two sets of ECP (Zones 2 and 5) had temperature sensors on the first pad and flushing the same cold-water volume when sensors reached 24°C (based on the first pad averaging 3°C lower temperature than the last pad) or every 4 min, whichever occurred first. Cold water for Zone 1 and 2 came from cooling tank 1 (Mean = 17.35°C) while Zone 5 cold water came from cooling tank 2 (Mean = 15.7°C). The water in both tanks was cooled using a 2 HP Hydro Frost Chiller. Daily ECP temperatures (PT), ECP flushing rate (FR), barn temperature (BT) barn relative humidity (RH) barn dewpoint (DP) and cooling tank temperature (TT) were collected every 10 min for the ECP variables and 30 mins for the environmental variables. Boars experienced varying natural summer heat stress (temperature and corresponding relative humidity and dewpoint: Mean = 25.3°C, 87.2%, 23.2°C; high: 29.0°C, 84.5%, 26.1°C), July 29, 2023. A mixed model was used for statistical analysis in SAS including fixed effects of zone and hour. FR and PT readings were affected by the zone, hour of day and all two- and three-way interactions (P < 0.001). All of the zones flushed more frequently late morning to afternoon (Mean: 64.6%) from 1100 to 1600 h and gradually the FR decreased in the evening (1900 h onwards). Zone 1 flushed more frequently (47.7%) than the 2 other zones (Zone 2 = 39.9%, Zone 5 = 33%). Zone 1 ECP temperature averaged 26.7°C (hourly mean range 26.1°C to 27.3°C). Zone 2 ECP temperatures averaged 22.1°C (hourly mean range 19.7°C to 24.1°C). Zone 5 ECP temperature patterns averaged 20.7°C (hourly mean range 19.1°C to 22.4). Zone 1 flushed less frequently (30.3%) at between 2100 to 0400 h. The following day and PT stayed cooler (Mean = 26.7°C) compared with the PT during the middle of the day (27.1°C).The set temperature (27°C; 24°C) or set time every 4 min kept the temperature of the ECP at desirable temperature, below 27°C for the last boar pad or below 24°C for the first of 5 pads (with approximate 3°C difference between the first and last of the of the 5 pads).
PSI-8 Impact of feeding level on boars from selection to entering the boar stud on trainability and growth measurements
Authors: Scaff Taw , Denton Alicia N , Ford Ally , Zaicow Emma , Richert Brian T , Stewart Kara R
Published: May 2024

The objective of this study was to determine if restricting feed in boars at selection impacts growth of boars or training for semen collection. Duroc boars (n = 25) randomly allotted at 6 mo of age to receive one of two levels of restricted feeding (1.8 kg/d, n = 12 or 2.72 kg/d, n = 13) of a corn-soybean meal-based diet formulated to meet NRC (2012) requirements. Diets were fed for 9 wk before training for semen collection where body weight (BW), body condition score (BCS), flank-flank tape measurements, Knauer sow caliper, loin muscle depth, backfat depth, and scrotal width and length were collected every 3 wk. Training for semen collection was conducted 5 d/wk for 2 wk. Boars were given 10 min in the collection pen to successfully mount the dummy and start collection each training session. Training was scored on a scale of 1-5, 1 = no interest and 5 = successful collection. After three successful collections in a row, boars were considered fully trained. All boars had their first production collection on wk 12. Data were analyzed using PROC MIXED and PROC FREQ chi-square in SAS 9.4 with boar serving as experimental unit. Weeks were analyzed individually and overall changes were evaluated. Significance was determined at P < 0.05 and a trend was observed at 0.05 < P ≤ 0.10. Boars fed 2.72 kg/d had increased BW on wk 9 (P < 0.05) and wk 12 (163.6 kg vs 149.8 kg, SE = 2.17; P < 0.001), increased BW gain wk 1-9 (P < 0.01), wk 9-12 (P < 0.001), and overall (49.8 kg vs 34.4 kg, SE = 1.60; P < 0.0001). The 2.72 kg/d boars also had increased backfat depth on wk 9 (P < 0.01) and wk 12 (8.4 mm vs 7.5 mm, SE = 0.17; P < 0.001), larger caliper scores on wk 12 (P < 0.01), greater flank-flank distance on wk 9 (P < 0.01), and increased BCS on wk 12 (3.2 vs 2.7, SE = 0.14; P < 0.01). No differences were observed for loin muscle depth, or scrotal width and length. Feeding level did not affect trainability with approximately 92% of boars being trained at the end of the two-week period in both feeding levels. Boars fed 2.72 kg/d had increased semen volume (128 mL vs 81 mL, SE = 12.1; P < 0.01) on their first production collection on wk 12 with no effects on other semen quality parameters. Overall, feeding boars 1.8 kg/d for 12 weeks following selection resulted in lower body weight and composition measures indicating limit feeding boars at selection could be used to slow growth rates, potentially decreasing structural issues, and increasing longevity of growing boars in the boar stud, with no effects on training for semen collection. Future research is needed to investigate the long-term impacts of the degree of limit feeding growing boars following selection on lifetime semen quality and quantity.

Keywords boar, management, nutrition