bluuebunny/crossref_metadata_2025 huggingface dataset:
PSIX-15 Elevated level of ATG12, an autophagy–associated gene, in canines with dermatological problems fed a polyphenol-rich food
Authors: Tavener Selena K , Badri Dayakar V , Panickar Kiran S
Published: September 2024

Autophagy is a controlled intracellular degradation process that removes damaged cellular components through a lysosome-dependent mechanism to maintain cell homeostasis and longevity. Autophagy related proteins (ATGs) require a series of conjugation to other proteins prior to their delivery to lysosomes for degradation. ATGs may also be involved in apoptosis. We assessed the role of ATGs and related genes in circulating leukocytes in dogs with dermatological issues. To investigate if ATG genes are modified with diet we fed 2 test foods (one rich in polyphenols) to canines with dermatological problems (n = 8) and controls (n = 8). Dogs were pre-fed a control food for 28 d and then divided into two groups based on their phenotype (Healthy, Derm) followed by a cross-over design. Dogs were fed for 42 d with test food 1 (TF1) and the second group was fed test food with a higher polyphenol content (TF2) for 42 d followed by a crossover. RNA was extracted from blood collected at the end of the pre-feed period, end of phase 1, and end of phase 2. Gene expression was assessed using NanoString nCounter platform. A mixed model analysis was performed using food as a fixed effect and animal as a random effect. TF2 fed dogs had low pruritus scores and increased the response rate (improvement %) to 30.77% when compared with dogs fed TF1. There was a significant increase in ATG12 in dogs fed TF2 compared with baseline (P < 0.05). But there was no difference in other ATGs including ATG5, ATG7, or ATG10 with TF1 or TF2. Autophagy involves the conjugation of ATG12 to ATG5 which promotes ATG8 to bind to the autophagic membrane which is essential for atuophagosome formation. ATG12 can also exert its action through a non-autophagy pathway by binding to Bcl-2 and inhibiting its activity to promote apoptosis. An increase in Bcl-2 was observed with TF2 and TF1 when compared with baseline (P < 0.05). An increased level of ATG12 and Bcl-2 in our study may have contributed to a decreased expression of selected inflammatory cytokines due to activation of apoptosis in leukocytes. Consistent with this, there was a decline in the expression of IL-5RA, a receptor expressed on eosinophils, TF2 group when compared with baseline (P < 0.05). There was also a decrease in FCRL2, a gene preferentially expressed in memory B-cells and plasma cells and also involved in B-cell receptor signaling, in dogs fed TF2 (P < 0.05). Whether increased ATG12 is directly responsible for an improvement in pruritus in dogs fed TF2 is not clear. However, our results indicate that ATG12 and Bcl-2 together may be involved in promoting apoptosis of pro-inflammatory leukocytes in dogs fed TF2 that may have resulted in a decline in inflammation.
PSIX-5 Performance of black soldier fly larvae meal as secondary protein sources in extruded dog diets
Authors: Kerr Katherine R , Gajda Angela M , Daristotle Leighann , Frantz Nolan
Published: September 2024

Black soldier fly larvae meal (BSFL) has gained market exposure with ties to sustainability and novelty. Graded inclusions of BSFL were assessed for nutrient digestibility, stool quality, and palatability in adult dogs. The BSFL was included at 0%, 5% and 10% in chicken-based extruded dog diets (formulated to 22% crude protein, 13% crude fat, 3% crude fiber). The study was approved by the facility’s Institutional Animal Care and Use Committee. A standard 2-bowl palatability test over a 2-d period was executed (n = 30 dogs each) to determine intake ratios between diets (0% vs. 5%, 0% vs. 10%, and 5% vs. 10%). Total tract nutrient digestibility was evaluated (n = 6 dogs per diet) with 5 d acclimation followed by 5 d total fecal collection. Stool quality was evaluated on a 1 to 5 scale. Palatability data were analyzed using paired t-test. To test for mean differences in digestibility and stool quality outcomes between 0%, 5%, and 10% BSFL dogs, we applied the Kruskal-Wallis test. Statistical significance was set at 5% type 1 error rate. Dry matter, protein, fat, and energy digestibility, and stool quality were similar between all diets (P > 0.05). Palatability was improved (P < 0.05) with inclusion of BSFL (i.e., preference for 5% and 10% vs. 0% inclusion) and improved (P < 0.05) at 10% vs. 5% inclusion. The BSFL tested showed merit as a palatable ingredient source that maintains stool quality and digestibility in adult dogs.
PSVIII-2 Effects of post-ruminal yeast cell wall extract on dry matter intake, gastrointestinal fermentation and permeability, and concentrations of white blood cell types in beef heifers exposed to feed restriction
Authors: Armes Wyatt D , Villot Clothilde , Chevaux Eric , Griebel Philip , Hogan Natacha , Mutsvangwa Timothy , Penner Gregory B
Published: September 2024

The objective of this study was to evaluate whether post-ruminal provision of a yeast cell wall extract (YCW) affected gastrointestinal fermentation characteristics and permeability, and white blood cell concentrations for heifers exposed to feed restriction (FR). Ruminally cannulated beef heifers (n = 8) were used in a 2 × 2 crossover design. Treatments (TRT) included an abomasal infusion of a placebo (PLC; maltodextrin) or YCW derived from Saccharomyces cerevisiae (2 g/dose) infused at 0600 and 1800 h. Heifers were subject to a 5-d baseline period followed by 5 d of FR where dry matter intake (DMI) was restricted to 30% of ad libitum intake. Data collection included daily DMI, and rumen, fecal and blood samples. Total gastrointestinal and post-ruminal permeability were measured using a ruminal dose of Cr-EDTA and an abomasal dose of Co-EDTA during the baseline and FR phases. Data were analyzed to determine the effects of YCW provision and phase, and the 2-way interaction. There were no TRT or TRT × phase interactions except for fecal propionate concentration. By design, DMI during FR was 30% (P < 0.01) of that observed during baseline (4.1 vs. 13.4 kg/d, respectively). The ruminal concentrations of acetate (45.4 vs. 69.2 mmol/L), propionate (14.5 vs. 26.7 mmol/L), and butyrate (9.9 vs. 16.5 mmol/L) were reduced (P < 0.01) by 34, 46, and 52%, respectively, with FR relative to baseline. Fecal propionate concentration (interaction, P = 0.04) numerically increased (P = 0.12) from baseline to FR for PLC (7.7 vs. 9.6 mmol/L, respectively), while YCW did not change among phases; however, no means differed. Exposure to FR reduced fecal butyrate concentration by 28% (P = 0.03). Gastrointestinal tract permeability (P < 0.01; 2.3 and 2.5% for total and post-ruminal, respectively) was greater during FR compared with baseline, with 2.0% of the Cr-EDTA and 1.6% of the Co-EDTA excreted in urine. The concentrations of neutrophils (P = 0.03) and eosinophils (P < 0.01) were greater during FR relative to baseline (2.28, 1.27 and 0.53, 0.30 ×106 cells/mL, respectively). Exposure to FR altered ruminal SCFA concentrations, increased blood concentrations of neutrophils and eosinophils, and increased gastrointestinal permeability suggesting an inflammatory response; however, post-ruminal provision of a YCW did not mitigate the response to a feed restriction challenge.
PSVIII-1 Identifying factors associated with the incidence of tibial dyschondroplasia in poultry
Authors: Amini Seyedehbaran , Jahnel Ricarda E , Makanjuola Bayode O , Bai Xuechen , Willems Owen W , Ellis Jennifer L , Baes Christine F , Leishman Emily M
Published: September 2024

Selecting on increased breast meat yield and body weight (BW) is thought to be associated with the increasing prevalence of leg disorders. A disorder of particular importance is tibial dyschondroplasia (TD), which is characterized as uncalcified cartilage in the proximal area of the tibiotarsal bone, leading to increased lameness, reduced feed and water intake, and subsequently poorer production efficiency and increased pre-slaughter mortality. Although it is hypothesized that TD is more prevalent in fast-growing poultry, this relationship can vary across studies making it challenging to distill the relationship between BW and TD, especially as studies of TD span several decades. Therefore, a systematic literature search and meta-analysis was conducted to identify factors influencing TD incidence. To date, the systematic literature search has resulted in 21 eligible papers, although data are still being extracted from the literature. Data extracted from each study included TD incidence (%), BW (kg), species (turkeys vs. broilers), sex (male vs. female), and age (weeks) of the animals. Preliminary univariable models have been developed based on the current database. Univariable generalized linear mixed models were developed in SAS (PROC GLIMMIX) including study as a random effect to evaluate the relationship between TD incidence and BW, species, sex, and age. Turkeys (27.3 ± 0.08%) had a greater TD incidence than broilers (19.3 ± 0.03%); however, this difference was not significant (P = 0.3481). There was a tendency for age to influence TD incidence (P = 0.0553) and a significant effect of BW (P < 0.0001). TD incidence also tended to differ between the sexes, with greater incidence in males (22.9 ± 0.07%) than females (11.3 ± 0.05%; P = 0.0657). After extracting all available data from the literature, further analysis will be conducted to consider multivariable models to predict TD. As such, caution should be used when generalizing these results due to the preliminary nature of the database. With the currently available data, the results of this study support the relationship between BW/size and TD. Furthermore, this study illustrates that TD is a prevalent challenge in both major poultry species. Reducing TD incidence could significantly improve animal welfare and mitigate economic losses associated with pre-slaughter mortality.
PSVIII-18 Chemical composition of residual yolk in response to feeding broiler breeders hydroxychloride or organic sources of zinc, copper, and manganese from 42 to 63 wk of age
Authors: Bakhshalinejad Reza , Torrey Stephanie , Kiarie Elijah
Published: September 2024

The objective was to investigate the effects of feeding broiler breeders (BB) hydroxychloride (HC) or organic (OR) sources of zinc (Zn), copper (Cu), and manganese (Mn) from 42 to 63 wk of age (woa) on chemical composition of residual yolk (RY). A total of 408 ♀ Ross 708 and 48 ♂ Yield Plus cockerels were placed in pens (17 ♀ and 2 ♂) housed in two rooms (12 pens/room) and allocated to one of two diets in a completely randomized block design (n = 12). The diets had similar nutrient specifications but differed in Zn, Cu, and Mn sources: 1) HO, a blend of 80% HC and 20% OR sources, and 2) OR, 100% OR sources ((Table 1 and 2). In total, 2,160 eggs (90 eggs from each pen replicate) were collected and labelled by BB pen at 46, 52 and 62 woa and incubated. For each incubation, embryos were euthanized at embryonic d (ED) 14 and 19 and at day of hatch (DOH) for the RY samples. On ED 14 and 19, six eggs per pen were individually weighed, and cracked open to dissect yolk sac and six hatchlings per pen (3 ♀ and 3 ♂) were individually weighed, and yolk sacs excised for DOH sampling. The RY weight (% of egg for ED or body weight for DOH), and dry matter and ash content were measured. The data at each sampling point was analyzed independently in a model with BB diet, age and associated interactions as fixed factors using PROC GLIMMIX procedures. There were no (P > 0.05) interactions between diet and BB age or main effects of trace mineral (TM) sources on any response criteria. The BB age effect was only observed for RY weight; in this context, the RY weight at ED 19 or DOH differed (P < 0.01) between BB age groups Table 3 and 4). Despite the lack of direct effects of TM sources on the measured criteria, these findings contribute to understanding the dynamics of RY composition in relation to BB age. Further research may explore additional factors influencing RY composition to optimize BB nutrition and subsequent offspring development.
PSXII-7 Forage quality and grazing dairy cattle performance as affected by the circadian rhythm: A meta-analytic investigation
Authors: Congio Guilhermo F S , Maciel Isabella C F , da Silva Sila C
Published: September 2024

The circadian rhythm alters forage chemical composition by balancing processes of photosynthesis, respiration, and transpiration. Timing of moving animals to a new paddock in a rotationally stocked system may take advantage of potential improvements in forage quality. The objective of this study was to collate available peer-reviewed papers aiming at comparing the forage quality and grazing dairy cattle performance when moved to a new paddock either in the morning (a.m.) or afternoon (p.m.). Twenty-four studies were gathered in total, and the number of observations per variable varied according to its availability within the studies. Among forage chemical composition parameters, contents of dry matter (DM), total non-structural carbohydrates (TNC), soluble carbohydrates (SC), starch, neutral-detergent fiber (NDF), acid-detergent fiber (ADF), acid-detergent lignin (ADL), ether extract (EE), crude protein (CP), and digestibility were assessed. The animal performance parameters included dry matter intake (DMI), milk yield (MY), energy-corrected milk yield (ECM), milk fat (MF) and milk protein (MP) contents, fat yield (FY), and protein yield (PY). A meta-analysis was performed according to a random effects model weighted by inverse variance (Comprehensive Meta-Analysis V3.3.070). Means, standard deviations or p-values, and number of observations were used to compute the effect sizes. Heterogeneity between observed effect sizes was examined with the Cochran’s Q test and the I2 statistic. The standardized mean difference was reported with its 95% confidence interval (CI), where positive values indicate an increment of p.m. compared with a.m., and negative values indicate a reduction. Statistical differences were declared significant at P ≤ 0.05, and trends were declared at P ≤ 0.10. Forage sampled in the p.m. had greater (P < 0.001) contents of DM, TNC, SC, starch, and digestibility by 19.8, 16.3, 21.3, 12.1, and 1.0%, while NDF (P < 0.001), ADF (P < 0.001), ADL (P < 0.001), and CP (P < 0.01) were decreased by 1.8, 2.4, 2.4, and 1.7% relative to a.m. forage, respectively (Table 1). Content of EE was not influenced (P > 0.05) by time. The ECM was 3.4% greater (P < 0.001) and the PY tended to be 3.7% greater (P = 0.07) for dairy cows moved in the p.m. compared with those moved in the a.m (Table 2). Dry matter intake, MY, MF, MP, and FY were not affected (P > 0.05) by time. Results indicate that even with considerable improvements of forage nutritive value in the afternoon, the benefits in terms of animal performance are small. Future studies assessing potential benefits of moving animals to a new paddock during the afternoon, should consider statistical power analysis and sample size calculation when designing the experiment.
PSXIII-10 Impacts of inoculation with Pediococcus pentosaceus in combination with chitinase on bale core temperature, nutrient composition, microbial ecology, and ruminal digestion of high moisture alfalfa hay
Authors: Wang Yuxi , Nair Jayakrishnan , Jin Long , Chevaux Eric , McAllister Tim A
Published: September 2024

Baling alfalfa hay at greater than optimal moisture (18% to 25%) can shorten wilting time and reduce field losses due to precipitation and leaf separation, but plant cellular respiration and the growth of spoilage microorganisms can reduce the nutritional value of baled hay. The objective of this study was to evaluate the effects of the application of Pediococcus pentosaceus NCIMB 12674 (PP) with various sources and concentrations of chitinase on conservation and nutritive value of alfalfa high-moisture hay (HMH). P. pentosaceus (1012 colony forming unit/tonne) combined with 1.5 (PP+LC), 7.5 (PP+MC) or 15.0 (PP+HC) g of chitinase/tonne fresh weight of 1st cut alfalfa (Exp. 1) or PP with chitinase from three different suppliers (PP+Fe, PP+Pe and PP+Si) were applied to 2nd cut alfalfa (Exp. 2) in 2016. In 2017, PP was applied alone or in combination with chitinase at 1.5 (PP+LC) or 7.5 (PP+MC) g/tonne of 1st cut (Exp. 3) and 2nd cut (Exp. 4) alfalfa. In all experiments, deionized water and propionic acid (PA) were applied as neutral (CON) and positive control (CON+), respectively. Bale temperatures were measured at 4-h intervals over the initial 60-d storage. Core hay samples were collected on d 30, 60, 90, and 120 of storage for chemical and microbial evaluation. Samples collected after 120-d storage were used to measure in situ dry matter and neutral detergent fiber (NDF) digestibility. Ambient-adjusted bale temperature was positively correlated (r2 = 0.44) to the moisture content of HMH at baling. The maximum temperature (Tmax) during 60-d storage was positively related (r2 = 0.66) to total microbial populations (bacteria + mold + yeast) with mold being the largest factor. The NH3-N concentration of the HMH increased with the total microbial population (r2 = 0.80) with mean bacterial numbers during d 30 to 120 being the main contributing (r2 = 0.83) factor. Treatments had no effect on total bacteria or lactic acid bacteria counts, while PP+MC had decreased yeast counts than CON after 60-d in Exp. 4 (P = 0.01) and after 120-d in Exp 3 (P < 0.001). Mold populations for bales treated with PP+HC at d 60 and PP+LC, PP+MC, and PP+HC at d 90 in Exp. 1, PP+MC at d 120 in Exp. 3 and CON+ at d 30 in Exp. 4 were all less (P < 0.05) than CON. The NDF digestibility after 72-h ruminal incubation was greater (P < 0.01) for PP+LC, PP+MC, and PP+HC than CON+ in Exp.1 and for PP+LC than CON in Exp 3 (P < 0.001). Combination of P. pentosaceus and chitinase have potential as additives to reduce microbial spoilage and to increase NDF digestibility of HMH.
PSVII-17 The effects of gamma-aminobutyric acid on growth performance, antioxidant capacity, rumen fermentation, and diarrhea in newborn calves before weaning
Authors: Zhang Yutong , Yang Yi , Bu Dengpan , Ma Lu
Published: September 2024

As antibiotic feed additives are being prohibited, alternative growth promoters that do not use antibiotics must be identified and developed for the livestock industry, notably for young animals like newborn calves. Gamma-aminobutyric acid (GABA) is a significant inhibitory neurotransmitter in the mammalian central nervous system that reduces blood pressure, stimulates feed intake, and enhances antioxidant capability. While GABA has been used as a feed additive for adult cows, little research has been conducted on GABA supplementation in calves. In this study, we examined GABA effects on the growth performance, antioxidant capacity, rumen fermentation, and diarrhea incidences in newborn calves. We randomized calves (n = 90) into five GABA-administered groups: 0 mg/d (G0), 25 mg/d (G25), 50 mg/d (G50), 100 mg/d (G100), or 200 mg/d (G200) were administered to animals from 11 and 75-d of age. Feed intake was recorded daily. Calves were individually fed twice a day (0600 h and 1400 h) and weaned at 75-d of age. Rumen fluid, serum, and fecal scores were collected at 11, 28, 42, 60, and 75-d of age. GABA addition (50 mg/d and 200 mg/d) numerically reduced diarrhea incidences in 11–28- and 11–75-d-old animals. GABA also had positive effects on average daily gain (ADG) and body height. The ADG in the 100 mg/d group was significantly higher than in controls (P = 0.004). GABA also increased butyrate concentrations and decreased methane (CH4) levels. In conclusion, GABA addition benefited newborn calves in terms of growth performance and diarrhea prevention. The optimal supplementation level was G100 (100 mg/d).
PSII-13 Analysis of variation characteristics within genes associated with temperament traits in horses
Authors: Choi Jae-Young , Kang Yong-Jun , Cho In-Cheol , Kim Hyeonah
Published: September 2024

Temperament traits in horses are key characteristics evaluated in assessing riding horses. The aim of this study is to explore the polymorphism of genetic variants associated with temperament traits using Jeju crossbred horses (a cross between Jeju horses and Thoroughbreds). To investigate the genetic characteristics of temperament in horses, analysis was conducted on 12 variants within 9 genes associated with temperament. Temperament traits were evaluated in 46 Jeju crossbred horses using a temperament test (assessing gentleness, patience, aggressiveness, sensitivity and friendliness) and a contact test (involving objects such as handkerchief, umbrella, plastic bag, air spray and whistle). The temperament test involved observers evaluating the behavior of the horses, while the contact test scored the reactions and movement distances of the horses when exposed to objects or sounds. Genetic variant analysis was performed using pyrosequencing. The association between genetic variants and temperament evaluation was analyzed using t-Tests and ANOVA tests to determine significance. Three variants (DDC rs394771481, GNAT3 rs395660537 and NLN rs1148100304) were found to be genetically fixed, while most variants, except for two (DRD5 rs68544696, ESR1 rs69463001), exhibited major allele frequencies of 0.8~0.9 (Table). Through association analysis between temperament traits and genetic variants, it was confirmed that the COMT(rs3431120406) variant was significantly associated with Aggressiveness, Friendliness, and Whistle responses. Additionally, significant differences in Whistle evaluation scores were observed based on genotypes in DRD5(rs68544698) and ESR1(rs69463001). This study suggests that genetic variations associated with temperament traits could serve as a theoretical foundation for evaluating temperament characteristics using Jeju crossbred horses.
PSLBI-27 Rumen microbiome dynamics in feedlot steers receiving free-choice garlic-infused mineral supplements
Authors: Holman Devin B , Gzyl Katherine E , Kommadath Arun , McAllister Tim A , Gonzalez Emmanuel , Durunna Obioha N
Published: September 2024

Garlic (Allium sativum) in its dehydrated or distillate (garlic oil) form has been used as a feed additive owing to its insecticidal, antimicrobial, and organoleptic properties. Commercial mineral mixtures have been formulated to contain a low proportion of dehydrated garlic powder as a strategy to deter pest flies and increase mineral intake in cattle. As an antimicrobial, garlic powder has the potential to alter the rumen microbiome, with possible implications for feed digestibility and the growth performance of beef cattle. This study evaluated the effect of short-term feeding of a garlic-mineral mixture in feedlot steers receiving high-grain diets. Four groups of twenty steers [total = 80, ~14 mo old, body weight (BW) = 599 ± 32 kg] were randomly assigned to either a 5% garlic-mineral (5DGP) or plain mineral supplement (MS). The individual feed and mineral intakes of the steers were measured with an automatic feeding system. Feed and mineral supplements were tracked in different bunks for each group. Baseline rumen fluid samples were collected from all steers at the end of an acclimatization period before administering the trial supplements. Rumen samples were later collected from 10 steers in each group with the greatest mineral supplement intake over the trial period. Total DNA and RNA were extracted from all rumen samples and subjected to metagenomic and metatranscriptomic sequencing, respectively. None of the bacterial species with an overall relative abundance of greater than 0.1% were differentially abundant between the two supplement treatments, nor did the rumen microbial community structures differ between the two groups (PERMANOVA: R2 = 0.02, P = 0.43). Regardless of the dietary supplement, the rumen microbiome of the steers was dominated by uncultured Prevotella spp. (in addition to Prevotella lacticifex) as well as the uncharacterized UBA2810 sp900317945 and UBA2810 sp002351705. Overall, these results show that a 5DGP can be effectively administered to cattle without significantly disrupting the rumen microbiome.
PSLBII-6 Measuring greenhouse gas emissions from biogas facility as manure treatment and comparing with 2006 IPCC guideline calculation
Authors: Park Geunwoo , Kim Dongwoo , Park Kyu-Hyun
Published: September 2024

To achieve global net-zero emission goals by 2050, Korea government announced 2050 carbon neutral scenarios. Substitution of fossil fuel power plants to renewable energy plants is the main strategic long-term vision. It included increasing the number of a biogas facility to retrieve methane (CH₄) for energy sources from manure. As increasing the biogas facility with using manure, it is important to quantify and monitor the greenhouse gas (GHG) such as CH₄ and nitrous oxide (N₂O). The objective of this research was to measure the GHG emissions from the biogas facility as the baseline to construct the country-specific emission factors, and to compare the emissions between site measured data and 2006 IPCC guideline (2006 IPCC GL). This facility was constituted with feedstock, anaerobic digestion, biogas storage, and liquid fertilizer storage. The facility treats 70 tons of swine manure from 20,000 pigs and 30 ton of food waste per day and generates 3,000 m3 /d of biogas. All gases were vented by negative pressure from the odor treatment tower, except the generator and its blowers. Quantification of the total GHG emissions from the biogas facility was conducted for 24 h every 2 wk, from July 2022 to October 2023, using CH₄/N2O Analyzer (Los Gatos Research, San Jose, CA). The total emissions of CH₄ and N2O were 12,545 ± 2,297 kgCH4/yr and 442 ± 1,123 kg N2O/yr. To compare total GHG emissions from the facility, it was changed by carbon dioxide (CO2) equivalent. The results showed that when the system of biogas facility operated normally, it can reduce the total GHG emissions by up to 60% compared with 2006 IPCC GL calculation. However, if the system does not circulate properly, it can result in 18 times greater emissions due to N2O, leading to significant increase in GHG emissions. To reduce GHG from biogas facilities, it is crucial to ensure continuous operation of organic matter in and out, and increase the amount of sufficient aeration in liquid fertilizer storage.
PSLBII-3 Influence of iron supplementation on insulin and glucose dynamics in horses
Authors: Gluck Cassandra R , Pratt-Phillips Shannon E
Published: September 2024

Iron is an essential micromineral involved in various physiological functions such as oxygen transport. The National Research Council’s Nutrient Requirements of Horses has iron requirements set at 400 mg iron daily for a 500 kg horse at maintenance; however, a survey found that Thoroughbreds consumed well over the daily requirement at 3,900 mg of iron from hay and grain alone. Additionally, a previous study has found a correlation between hyperinsulinemia and increased ferritin, an indicator of iron body stores. Therefore, the objective of the present study was to determine the effects of iron supplementation on body iron stores as well as insulin and glucose dynamics. It was hypothesized that iron supplementation would influence body iron stores and insulin and glucose responses. Mixed-breed geldings [n = 12; 558.9 ± 74.4 kg body weight (BW)] were housed individually for the study. Horses were fed 2% of their BW in grass hay and an iron-free vitamin mineral supplement, consuming an average of 600 mg of iron daily for the first 28 d (Hay Phase). Horses were then assigned to continue on the hay diet (CTRL; n = 4) or an iron-supplemented diet (IRON; n = 8), in which an oral iron supplement was given daily in the form of ferrous sulfate, with IRON horses consuming an average of 4,000 mg of iron daily for 28 d (Supplement Phase). Oral sugar tests (OSTs) were performed at the beginning of the study as well as the end of each phase, using a 0.45 mL/kg of BW Karo Light Syrup dose to determine insulin response, with jugular venous samples taken prior to the dose and 60 min after. All statistical analysis was performed in GraphPadPrism Version 10.2.0 (GraphPad Software, Boston, MA), using analysis of variance for repeated measures and correlation analysis. All OSTs throughout the study had a significant time effect (P < 0.05) for both insulin and glucose. There was a time X treatment trend (P = 0.1) for insulin during the Supplement Phase and when using multiple comparisons, insulin response was significantly greater (P < 0.0007) at 0 versus 60 min in IRON horses. Although there was no correlation found between 60-min insulin and ferritin concentrations in both IRON and CTRL horses, mean ± SD insulin and ferritin in the IRON group were 23.6 ± 10 uU/mL and 570 ± 195.8 ng/mL, respectively, while in the CTRL group these were 12.7 ± 2.9 uU/mL and 453 ± 31.1 ng/mL, respectively. In conclusion, iron supplementation with an inorganic form at 10 times the daily requirement appears to result in increased insulin responses as well as body iron stores. Further research needs to determine if feeds naturally enriched in iron impact glucose metabolism.
PSLBII-27 Investigating the emergence of antimicrobial resistance in Mycoplasma bovis from feedlot cattle
Authors: Andrés-Lasheras Sara , Zaheer Rahat , Ruzzini Antonio , Jelinski Murray D , McAllister Tim A
Published: September 2024

Bovine respiratory disease (BRD) is the most significant disease affecting feedlot cattle in North America. Mycoplasma bovis is among the main BRD pathogenic bacteria. Infection control of M. bovis is hampered by a lack of effective vaccines and increasing antimicrobial resistance (AMR). Integrative and conjugative elements (ICEs) have been documented as a mechanism of horizontal gene transfer (HGT) in mycoplasmas. Mycoplasma ICEs (MICE) do not carry AMR genes but have been associated with the HGT of genes that confer AMR through point mutations. Hence, there is a need to gain a better understanding of the role of MICE in M. bovis AMR. Randomly selected M. bovis isolates (n = 54) collected from Western Canadian feedlot cattle (AB and SK) underwent whole-genome sequencing by short-reads (Illumina), with a subset (n = 6) selected based on AMR and ICE profiles for Oxford Nanopore long-read sequencing. Sequences were screened for the presence of MICE. MICE circularization (cMICE) is the first step of conjugation, and an in-house collection of 472 M. bovis field isolates (feedlot cattle just from AB) was screened by PCR for the presence of cMICE as a proxy for conjugation capabilities. Environmental conditions that could impact cMICE quantity, including growth phase, temperature, cell density, pH, starvation, UV light, CO2 concentration, and sub-inhibitory concentrations of mitomycin C were investigated by qPCR, followed by growth of M. bovis isolates under the most favorable conditions identified for cMICE-detection and screening by a high throughput qPCR method that eliminated the need for DNA extraction. Nineteen different mating pairs were carried out and 4 different environmental factors were tested for their possible impact on conjugation occurrence (incubation time, incubation volume, conjugation parent proportions, atmosphere). All isolates carried MICEs with 23/54 having a structure/sequence comparable to previously described functional MICE in mycoplasma, 43/54 possessing non-functional ICE, and 23 having >1 ICE. The presence of more than one MICE/genome suggests a lack of MICE (entry) exclusion systems in M. bovis, a trait that may promote the flow of genetic information among M. bovis isolates including AMR. Even though some factors including growth phase (early stationary phase) and pH (9.0) generated greater levels (≥1.5 fold) of cMICE, none of the examined parameters were statistically significant. However, as early stationary growth phase generated the greatest cMICE quantity (2.3 fold), M. bovis isolates were cMICE-screened at this growth stage for the expeditious identification of M. bovis conjugation candidates. A total of 25.7% M. bovis were cMICE-positive. Of 19 mating pairs tested, transconjugants were recovered from only 2 different mating pairs, possibly reflective of the need for further optimization of conjugation conditions.
PSLBII-25 Impact of strain and sex on hematological and serum biochemical characteristics of broiler chickens in Ikorodu, Lagos, Nigeria
Authors: Anjola Olugbenga A , Onigemo Murisiku , Agbaye Peter , Asafa Rafiu , Ishola Olawale , Agbalaya Khadijah , Tijani Lateef , Oso Yusuf
Published: September 2024

This experiment was conducted to evaluate the influence of strain and sex on the hematology and serum biochemistry of broiler chicken reared in Ikorodu area of Lagos, Nigeria. A total of 153 unsexed broiler birds containing 51 of Marshall, Arbor Acre and Cobb strains each were used for the experiment. The birds were reared under the same condition for 8 wk. Blood samples, collected from the jugular veins, were used to determine hematological parameters including Hemoglobin (Hb), packed cell volume (PCV), red blood cell (RBC), white blood cell (WBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), neutrophils (NEUT), lymphocyte (LYMP) monocytes (MON) and eosinophils (EOS). However, the serum biochemical indices include the total protein (PRO), serum glucose (GLU), serum albumin (ALB), uric acid (URIC), alkaline phosphatase (ALP) and Serum Cholesterol (CHOL) and creatinine. Statistical analysis revealed that Hb, WBC, EOS, MCHC and Serum cholesterol were significantly influenced by strains and sex while PCV, RBC, NEUT, LYMP, PRO, GLU, ALP and uric were significantly affected by sex of broiler chicken (Table 1-4).
PSI-29 Enhancing growth performance and reducing environmental impact with dietary protease supplementation in growing pigs fed high- and low-density diets
Authors: Tactacan Glenmer B , Babatunde Olufemi O , Lahaye Ludovic
Published: September 2024

Exogenous protease has emerged as a promising solution for enhancing protein digestion and utilization in animal diets, offering potential benefits for both animal performance and environmental impact mitigation in pig farming. In a 6-wk trial involving 140 growing pigs [initial body weight (BW) = 24.10 ± 1.66 kg], the effects of dietary protease supplementation on growth performance, nutrient digestibility, and noxious gas emission were investigated. Pigs were randomly assigned to one of four dietary treatments in a 2 x 2 factorial design with two levels of nutrient density and 0 or 125 g/ton supplementation of protease. The pigs were blocked by BW and housed in 28 pens with each pen consisting of 5 pigs (3 barrows and 2 gilts). The experimental design employed a randomized complete block design with 7 replicate pens per treatment. The data were analyzed using two-way ANOVA, with differences between means assessed using Tukey’s test (P < 0.05). Results revealed no significant interaction (P > 0.05) between nutrient density and protease supplementation concerning growth performance, nutrient digestibility, and noxious gas emission. Pigs subjected to high-density diets exhibited greater (P < 0.05) average daily gain (ADG) and gain-to-feed ratio (G:F) compared with those on low-density diets. While protease supplementation did not impact ADG and average daily feed intake (ADFI), there was a tendency towards reduced (P = 0.08) G:F throughout the 6-wk period. Pigs fed high-density diets demonstrated significantly greater (P < 0.05) apparent total tract digestibility (ATTD) of gross energy (GE) compared with their counterparts on low-density diets. Furthermore, the inclusion of protease significantly increased (P < 0.05) ATTD of GE. However, no discernible differences were noted among diets regarding the ATTD of dry matter and nitrogen. Regarding noxious gas emission, protease supplementation did not significantly affect total mercaptans and hydrogen sulfide (H2S) emission. Nonetheless, there was a notable trend towards reduced (P = 0.06) ammonia gas (NH3) emission with protease inclusion. Similarly, nutrient density did not exhibit a significant effect (P > 0.05) on noxious gas emission. In conclusion, the results of the study underscore the importance of nutrient density and protease supplementation in optimizing pig performance and environmental sustainability in swine production systems. Further research is warranted to elucidate the underlying mechanisms and refine strategies for maximizing the benefits of these dietary interventions.
PSII-22 Effects of protease supplementation on ileal digestibility of amino acids in pulse grains fed to growing pigs
Authors: Lee Jinyoung , Patterson Rob , Nyachoti C Martin
Published: September 2024

Pulse grains, such as chickpeas, faba beans, and lentils are non-oil seed legume crops and good sources of starch and protein as alternative feed ingredients to cereal grains or soybean meal. This study aimed to determine the effects of protease supplementation on the apparent (AID) and standardized (SID) ileal digestibility of amino acids (AA) in chickpeas, faba beans, and lentils fed to growing pigs. A total of twelve ileal cannulated barrows (55.7 ± 3.6 kg initial body weight) were assigned to one of six dietary treatments in a replicated 6 × 3 incomplete Latin square design, with six treatments and three 7-d periods to give six observations per dietary treatment. Six treatments consisted of one of the pulse grains with or without protease supplementation (250 g/tonne). Each pulse grain was included as the sole source of protein in the diets, and a casein diet was fed to all pigs for a week after feeding experimental treatments to quantify endogenous losses of AA. All diets contained 0.3% titanium dioxide as an indigestible marker. Pigs underwent surgery to install T-cannulas at the distal ileum. Each period lasted for 7 d including 5 d of adaptation and 2 d of ileal digesta collection. Data were analyzed as a 3 × 2 factorial arrangement with the 3 different pulse grains and with or without protease supplementation, using the PROC MIXED of SAS. The statistical model included type of ingredients, protease supplementation, and their interaction as fixed effects, and replication, animal within replication, and period within replication as random effects. Protease supplementation decreased (P < 0.05) the AID of Thr, Trp, Ala, Cys, and Gly, and decreased (P < 0.05) SID of Trp, Ala, and Cys. The SID of all AA except for Gly and Pro were greater (P < 0.05) in lentil and faba bean diets compared with those in the chickpea diet. There were no interactive effects in the AID and SID of AA except for the AID of Pro, where AID did not differ between with and without protease supplementation in chickpea and faba bean diets, however, protease supplementation decreased (P < 0.05) AID of Pro in lentil diet compared with without protease supplementation. In conclusion, the digestibility of AA in growing pigs was greater without protease supplementation, and no interactive effects were observed in general between the type of ingredient and protease supplementation. Future studies will aim to investigate the dose-effect to accurately determine whether the observed effect was attributable to improper enzyme-to-substrate ratio.
PSII-17 Effect of dietary β-mannanase supplementation on energy and nutrient utilization in diets fed to broiler chickens: A meta-analysis
Authors: Kim Hyun Woo , Lee Ji Hye , Lee Jae-Hwan , Kil Dong Yong
Published: September 2024

Beta-mannan (β-mannan) is a polysaccharide composed of repeating units of mannose, galactose, and glucose. The increased amount of β-mannan is present in various plant protein sources such as soybean meal, palm kernel meal, copra meal, and guar meal. β-mannan is considered an antinutritional factor for non-ruminant animals. Endo-β-mannanase enzymes are endo-hydrolases that can cleave the internal glycosidic bonds of the mannan backbone. As a result, β-mannanase is used to break down β-mannan in animal feeds, thereby aiming to reduce its potential anti-nutritional effects. Previous research has demonstrated that dietary β-mannanase supplementation improves energy and nutrient utilization in broiler diets possibly by decreasing digesta viscosity in the gastrointestinal tract. However, results from previous studies have been inconsistent, mainly due to variable experimental conditions including animals, experimental design, and environment. Meta-analysis is a useful method to comprehensively evaluate and integrate various results from previous studies, thereby providing reliable and practical insights. Therefore, the objective of this study was to conduct the meta-analysis to evaluate the effect of dietary β-mannanase supplementation on digesta viscosity, and energy and nutrient utilization in diets for broiler chickens. Through an extensive literature search conducted on Scopus, PubMed, Web of Science, and Google Scholar between January 2003 and December 2023, we identified 10 eligible studies. The meta-analysis was performed using the “metafor” package in R software version 4.1.3. (R Core Team, 2023), and the standardized mean difference (SMD) and its 95% confidence interval (CI) were calculated using the random effect model. The results revealed that dietary β-mannanase supplementation increased apparent total tract retention (ATTR) of dry matter (SMD = 1.84; 95% CI: 0.46 to 3.21; P = 0.016), gross energy (SMD = 2.16; 95% CI: 1.19 to 3.12; P = 0.001), and nitrogen-corrected apparent metabolizable energy (AMEn) in broiler diets (SMD = 3.38; 95% CI: 1.63 to 5.14; P = 0.002; Table 1). Moreover, dietary β-mannanase supplementation increased apparent ileal digestibility (AID) of gross energy (SMD = 6.65; 95% CI: 3.78 to 9.53; P = 0.002) and nitrogen (SMD = 1.41; 95% CI: 0.55 to 2.27; P = 0.006) in broiler diets (Figures 1 and 2). Finally, digesta viscosity (SMD = -3.35; 95% CI: -4.69 to -2.02; P < 0.001) in broiler chickens was decreased by dietary β-mannanase supplementation. In conclusion, the current meta-analysis indicates that dietary β-mannanase supplementation improves the overall utilization of energy and nutrients in diets with decreasing digesta viscosity in broiler chickens.
PSXIII-11 Large-scale profiling of non-conventional peptides in several tissues of Yak (Bos mutus) by peptidogenomic pipeline
Authors: Li Biao , Jiang Zhihua , Yang Jinzeng
Published: September 2024

Wild Yak (Bos Mutus) has great research value in understanding ruminant animal physiology and biomedicine as a model of plateau hypoxia adaptation. Non-conventional peptides (NCPs), including small open reading frame-encoded peptides, have been found to have a key role in basic plant and animal biological processes. In this study, we first developed an integrated peptidogenomic pipeline, used high-throughput mass spectrometry to probe a customized six-frame translation database, combined genome, transcriptome and translatome analysis, and applied it to large-scale identification of NCPs in several important tissues related to metabolism, immunity, digestion and reproduction in yaks. Here we report that 9,550, 7,016, 7,958, 7,537, 7,921 and 13,973 NCPs were identified in liver, lung, spleen, muscle, testis and small intestine, respectively. These NCPs have distinct characteristics and differences from conventional peptides in which they are derived from introns, 3 ‘UTR, 5’ UTR, out-of-frame exons, and intergenic regions (IGRs). In addition, although NCPs were identified in a wide range and existed in various tissues of yaks, they also showed differences in tissue expression. Interestingly, we also found that the number of hydrophobic amino acids in NCPs was greater than that of hydrophilic amino acids in different tissues of yaks, but the result of CPs was opposite. These results indicate that they may be related to the maintaining protein stability and anti-oxidative stress. The physiological functions were further verified by the in vitro antioxidant activity of 20 candidate peptides, but the specific physiological mechanisms remain to be further investigated. In summary, our study developed an integrated peptidogenomic pipeline for the first time to extensively identify NCPs in wild yaks, indicating that a large portion of yak genome can be translated into molecules with biological functions, which is of great significance for functional genomic studies and provides a reference for the discovery of new functional genes for environmental adaptability of ruminant animals.
PSXI-6 Effects of termite frass inclusion in free range broiler beddings on growth, footpad dermatitis score, and blood profiles
Authors: Tsukahara Yoko , Egawa Satoshi , Ijiri Natsuko , Kato Akane , Togawa Hiroyuki , Tomonaga Shozo , Kumagai Hajime , Hirooka Hiroyuki , Matsuura Kenji
Published: September 2024

Research on insects as feed has gained attention in the last decade. Among insect species, we have focused on termites, which degrade lignocellulose and synthesize protein by employing gut microbiota. In particular, the damp-wood termite Hodotermopsis sjostedti subsisting on rotten wood, excretes a substantial portion of wood as frass, serving as their primary nest material. Termite frass, a by-product of termite production, has been found to comprise approximately 83% lignin, suggesting potential antibacterial properties. In this study, the effects of termite frass inclusion in free-range broiler chicken bedding on growth, meat and organ weights, blood profile, and footpad dermatitis (FPD) score were examined. Broiler chicks [n = 30; 0 d of age and initial body weight (BW) = 47.1 ± 0.51 g] were divided into three groups and resided in a 1.3 m2 pen fed on a commercial diet. The groups were subjected to one of the three bedding treatments: 7.5 kg sawdust (0% frass), 7.5 kg sawdust plus 7.5 kg termite frass (100% frass), and 7.5 kg sawdust plus 15.0 kg termite frass (200% frass). Intakes and BW were measured weekly, and the FPD score was assessed at 3, 5, 6, and 7 wk. At 50 d of age, the chickens were slaughtered for meat and organ weights and blood profile analyses. Growth data, meat and organ weights, and blood profiles were analyzed by GLM of SAS, and the weekly FPD score was analyzed by GLIMMIX as binomial data. Average daily gain and final BW were greater (P < 0.001 and P = 0.003, respectively) in chickens for 0% and 200% frass treatments than in 100%. Thigh and fillet meat weights were similar among the treatments, whereas breasts tended to be lighter (P = 0.064) for 100%. Footpad dermatitis scores tended to be greater (P = 0.085) for 200% than for 100%. Among organ weights tested (e.g., liver, heart, spleen, ventriculus, proventriculus, pancreas, cecum, intestine), heart weight was heavier (P = 0.044), whereas proventriculus was lighter (P = 0.022) for 200% than for 100%. On the other hand, cecum weight tended to be heavier (P = 0.075), and intestine tended to be lighter (P = 0.093) for 0% than for 100% and 200% treatments. Plasma alanine transaminase (ALT) and lactate dehydrogenase (LD) were less (P < 0.001 and P = 0.04, respectively) for 100% and 200% than for 0%. In conclusion, termite frass inclusion in free-range chicken bedding had slightly adverse trends on FPD; however, 200% inclusion did not alter the growth performances of chickens. It also suggested that frass inclusion would have preferable effects on chicken health based on plasma ALT and LD values. Further investigation is required for the different organ weights and their effects, such as heart, proventriculus, cecum, and intestine.