Mo Of Age Research Articles

Residual feed intake measured as replacement heifers is indicative of residual feed intake measured as mature cows

This study aimed to quantify the relationship between residual feed intake (RFI) measured in 500 heifers and subsequently as mid-gestation cows at the Roy Berg Kinsella Research Station (KIN; n=227) and Lacombe Research and Development Centre (LRDC; n=273). Heifers were initially tested for RFI adjusted for end of test rib fat (RFIfat) at 8-12 mo of age and then again as 3-yr old first-calf heifers at KIN and as 4-13 yr old cows at LRDC. Heifer RFIfat measured in drylot on a forage diet was associated (R2 >0.53; P < 0.001) with RFIfat measured again as older cows. Each 1 kg DM d-1 change in heifer RFIfat equaled 0.48±0.10 and 0.75±0.19 kg DM d-1 change in cow RFIfat for KIN and LRDC, respectively. Linear effects were also reported for RFIfat component traits, where DMI (P<0.001), ADG (P<0.060), mid-test metabolic weight (P<0.001) and end of test rib fat (P<0.001) measured as heifers were related when measured again as older cows. In addition, the linear effects of heifer RFIfat on cow RFIfat were constant across cow age groups from 4-10 yr of age. These results show that selection for RFI in heifers will result in cows that are also more feed efficient.

Age- and sex-specific biomechanics and extracellular matrix remodeling of the ascending aorta in a mouse model of severe Marfan syndrome.

Thoracic aortic aneurysm (TAA) is associated with Marfan syndrome (MFS), a connective tissue disorder caused by mutations in fibrillin-1. Sexual dimorphism has been recorded for TAA outcomes in MFS, but detailed studies on the differences in TAA progression in males and females and their relationships to outcomes have not been performed. The aims of this study were to determine sex differences in the diameter dilatation, mechanical properties, and extracellular matrix (ECM) remodeling over time in a severe mouse model (Fbn1mgR/mgR = MU) of MFS-associated TAA that has a shortened life span. Male and female MU and wildtype (WT) mice were used at 1-4 mo of age. Blood pressure and in vivo diameters of the ascending thoracic aorta were recorded using a tail-cuff system and ultrasound imaging, respectively. Ex vivo mechanics and ECM remodeling of the aorta were characterized using a biaxial test system and multiphoton imaging, respectively. We showed that mechanical properties, such as structural and material stiffness, and ECM remodeling, such as elastic and collagen fiber content, correlated with diameter dilatation during TAA progression. Male MU mice had accelerated rates of diameter dilatation, stiffening, and ECM remodeling compared with female MU mice which may have contributed to their decreased life span. The correlation of mechanical properties and ECM remodeling with diameter dilatation suggests that they may be useful biomarkers for TAA progression. The differences in diameter dilatation and life spans in male and female MU mice indicate that sex is an important consideration for managing thoracic aortic aneurysm in MFS. NEW & NOTEWORTHY Using a mouse model (Fbn1mgR/mgR = MU) of severe thoracic aortic aneurysm in Marfan syndrome (MFS), we found that male MU aorta had an accelerated time line and increased amounts of dilatation, stiffening, and extracellular matrix (ECM) remodeling compared with female MU aorta that may have contributed to an increased risk of fatigue failure with cyclic loading over time and a reduced life span. We suggest that aortic stiffness may provide useful information for clinical management of aneurysms in MFS.

Olfactory deficit and gastrointestinal dysfunction precede motor abnormalities in alpha-Synuclein G51D knock-in mice

Parkinson's disease (PD) is typically a sporadic late-onset disorder, which has made it difficult to model in mice. Several transgenic mouse models bearing mutations in SNCA, which encodes alpha-Synuclein (α-Syn), have been made, but these lines do not express SNCA in a physiologically accurate spatiotemporal pattern, which limits the ability of the mice to recapitulate the features of human PD. Here, we generated knock-in mice bearing the G51D SNCA mutation. After establishing that their motor symptoms begin at 9 mo of age, we then sought earlier pathologies. We assessed the phosphorylation at Serine 129 of α-Syn in different tissues and detected phospho-α-Syn in the olfactory bulb and enteric nervous system at 3 mo of age. Olfactory deficit and impaired gut transit followed at 6 mo, preceding motor symptoms. The SncaG51D mice thus parallel the progression of human PD and will enable us to study PD pathogenesis and test future therapies.

PSI-7 Creation of gene-edited pigs for functional analysis of growth hormone receptor promoters in swine

Abstract Growth hormone (GH; somatotropin) has a central role in animal growth, reproduction, and lactation. The biological actions of GH are dependent on the GH receptor (GHR) that is found in important target tissues such as liver, muscle, adipose tissue, and bone. It is widely accepted that GH is the primary hormone controlling animal growth and that its actions are mediated by the GHR. In humans, laboratory species, and farm animals there are two promoter complexes that control GHR expression. The first promoter complex (P1) controls the liver-specific inducible expression of the GHR1A mRNA. The second promoter complex (P2) controls the non-tissue specific constitutive expression of GHR1B mRNA. Despite the central role that GH and the GHR have in animal growth, the independent function of each promoter complex has not yet been tested in any species. The objective was to perform a germ-line deletion of each GHR promoter complex to test their function in a porcine model. The CRISPR/Cas9 system was used to delete the P1 and P2 promoter complexes in porcine fetal fibroblasts and cloned to create two independent lines for each promoter deletion. Adult animals that were heterozygous (het) for the GHRP1 and GHRP2 deletions were mated to create litters of +/+ (wildtype, WT), +/- (het), and -/- (knockout, KO) pigs for the respective promoters. An RTPCR of liver and muscle confirmed that deletion of GHRP1 and GHRP2 effectively knocked out GHR1A and GHR1B mRNA. Piglets were weighed at birth and approximately monthly until 2 (GHRP1) or 5 (GHRP2) mo of age. Piglets from the GHRP1 line were +/+ (n = 3), +/- (n = 10), and -/- (n = 2) across two litters. Birthweights (1.5 ± 0.1, 1.4 ± 0.1, and 1.5 ± 0.2 kg, respectively) and body weight (BW) at 2 mo of age (32.7 ± 2.9, 27.0 ± 1.6, and 27.0 ± 3.5 kg, respectively) were similar (P > 0.10) for GHRP1 piglets. Piglets from the GHRP2 line were +/+ (n = 2), +/- (n = 6), and -/- (n = 9) across two litters. Birthweights were similar (1.4 ± 0.3, 1.3 ± 0.1, and 1.0 ± 0.1 kg, respectively) but GHRP2-/- pigs weighed less (P < 0.01) at weaning compared with GHRP2+/+ or GHRP2+/- piglets (6.4 ± 0.8, 6.5 ± 0.4, and 4.5 ± 0.4 kg, respectively). Monthly BW for the GHRP2-/- piglets were less (P < 0.001) when compared with GHRP2+/+ or GHRP2+/- piglets. At 5 mo of age, the GHRP2-/- piglets were approximately 50% of the BW of GHRP2+/+ or GHRP2+/- (89.6 ± 6.7, 89.6 ± 3.9, and 43.1 ± 3.2 kg, respectively). In conclusion, the deletion of GHRP2 (and GHR1B mRNA) had a profound effect on pig growth. The GHRP1 deletion (GHR1A mRNA) did not affect growth with the caveat that the GHRP1 litters had not reached maturity. This work was supported by USDA NIFA 2019-67015-29484.

PSLBII-1 Enhancing cattle health and performance through targeted supplement optimization and evaluation

Abstract Our objective is to evaluate and optimize Bovi-MV formulation through its effect on serum mineral/vitamin (M/V) concentrations in cattle and develop a systems approach to oral M/V supplementation through the lifecycle of beef cattle to determine the best management strategy to help reduce M/V deficiencies in young and mature animals. Cow/calf pairs (n = 300 over 2 yr) and follow the calves to harvest late in yr 2. The research is timed to coincide with typical management handling processes (e.g., vaccination of cows before calving and calf processing after birth, before pasture, at weaning time, on induction to the feedlot, and at reimplanting). The calf herd will be divided at birth into treatment (calves whose dams received BoviMV supplement) and control (~150 calves per group). Vitaferst-Care will be provided to the treatment group at processing (vaccination, antiparasitic application) before going to grass (~ 3 mo of age). Bovi-MV will only be given to the treatment group. All calves will be administered a tracer vaccine to assess their immune response. Blood samples will be collected from all calves for antibody titer testing at weaning (~ 6 mo of age). The treatment calves will also receive a booster dose of Bovi-MV at that time. Approximately 90 d after weaning (~ 9 mo of age) antibody titer will be determined immune response was. Calf morbidity, mortality, and performance (average daily gain) will be monitored in the feedlot. An accredited lab will conduct M/V blood analysis; antibody titer testing will be done at a Lakeland College lab. Based on MV and titer to the Bovi-MV supplement and tracer vaccine, the formulation of the Bovi-MV will be evaluated, and recommendations will be made. Based on results from two previous studies evaluating M/V blood concentrations in cattle (Neonatal supplement and Itchy Cow) in Western Canada, vitamin and mineral concentrations tended to be below optimum values, especially in herds provided supplementation free choice. All cows were deficient in vitamin A at calving, averaging 66.27 ± 2.51 ppb, with 50% having nondetectable concentrations. With vitamin E, 8 animals had nondetectable concentrations, only 8 had sufficient concentrations, and those with detectable concentrations averaged 3.16 ppm ± 2.17. Cows had sufficient iron ug/mL averaging 2.14 ± 1.02 and selenium ug/mL 0.09 ± 0.02. As Cheryl Waldner et al. (2023) reported, 24 to 43% copper deficiency is prevalent in cattle in the southern halves of the three prairie provinces. Armed with this information, this study is the first step in developing a systems approach to year-round management of the cow herd’s vitamin and mineral supplementation.

PSXIII-8 Determining the effects of selenium content of high-selenium forages on weight gain in growing lambs

Abstract High selenium (Se) forages grow on seleniferous soils in many parts of the world and upon Se-contaminated rangelands such as in the Western Phosphate Resource Area in the western United States. When consumed in large enough amounts or for extended durations, animals can be poisoned, developing acute or chronic selenosis. Naïve livestock will indiscriminately consume forage with increased concentrations of Se if available. However, most animals upon ingesting a sublethal Se dose will become averted to Se-rich plants and select forages with decreased Se concentrations. The purpose of this study was to determine Se concentrations in feed that cause reduced feed intake and decreased body weight (BW) gain in growing lambs (6 to 8 mo of age). Lambs (n = 5) were randomly divided into four groups and were fed a control pellet (< 1 ppm Se) at 1.5% of their BW and had free choice to a custom Se alfalfa pellet containing < 1 (control), 10, 20, or 40 ppm Se for 8 wk. During the 8 wk period the lambs gained 32.9 ± 4.1, 27.8 ± 1.8, 18.9 ± 9.2, and 7.4 ± 2.8% (mean ±SD) of their initial BW in the < 1 (control), 10, 20, or 40 ppm Se groups, respectively. After the 8 wk were completed, the lambs were fed only the custom Se alfalfa pellets, with < 1 (control), 10, 20, or 40 ppm Se, free choice for four additional weeks. As Se concentration in the pellets fed increased, the feed intake and BW gains significantly decreased. Lambs in the control and 10 ppm Se groups ate approximately 2-fold more than the lambs in the 40 ppm Se group, which lost over 3% of their initial BW. Understanding the concentration of Se in forages and how it affects appetite and BW gain allows range managers to better manage seleniferous or Se-contaminated ranges to safely use sheep on these types of rangelands. Additional work is needed to better understand the management of other livestock species grazing on high Se-containing ranges and pastures.

PSXII-19 Influence of dietary copper concentration and liver sampling location on liver copper concentrations in three breeds (Gulf Coast Native, Suffolk x Hampshire, and Jacob) of sheep

Abstract Male sheep (n = 27) from three different breeds: 1) Gulf Coast Native (GCN; n = 9 wethers), 2) Suffolk x Hampshire (SHC; n = 9 wethers), and 3) Jacob (JCB; n = 9 intact males) approximately 9 mo of age, [body weight (BW) = 38.16 ± 2.43 kg) were stratified by BW and breed into 3 treatment groups to examine the impact of breed, supplemental copper (Cu) dose, and liver sampling location on liver Cu concentrations. On d 0 of the experiment, liver biopsies were collected from 5 sheep per breed and analyzed for Cu concentrations. Animals were housed in individual pens and received 2% of BW of a pelleted concentrate containing the appropriate Cu treatment once daily and hay in amounts to allow ad libitum access to hay over a 24 h period. Treatments consisted of 1) low Cu (LCu; 15.3 mg Cu/kg DM), 2) moderate Cu (MCu; 17.7 mg Cu/kg DM), and 3) high Cu (HCu; 23.8 mg Cu/kg DM) from CuSO4∙5H2O. On d 50 of the experiment, all animals were weighed and transported to an USDA inspected abattoir and harvested. Following harvest, samples were obtained from the left and right lobes of the liver and thoroughly washed with phosphate-buffered saline. All liver samples were dried, ashed, and reconstituted in 5 mL of 1.2 N HCl for Cu analysis. Data were analyzed as a randomized block design using the MIXED procedure in SAS with individual animal as the experimental unit. There was a three-way interaction between breed x treatment x liver lobe (P < 0.04). The right liver lobe in HCu JCB sheep had greater (P < 0.05) Cu concentrations compared with the left liver lobe. Both the left and right lobes of the liver had greater (P < 0.001) Cu concentrations compared with the initial liver Cu concentration in MCu JCB sheep. The right liver lobe of HCu GCN sheep tended (P < 0.07) to have greater liver Cu concentrations compared with the left liver lobe. The Cu concentration in the right liver lobe tended (P < 0.09) to be greater in MCu sheep compared with the left liver lobe. Liver Cu concentrations within the right lobe of HCu GCN sheep were greater (P < 0.05) than liver Cu concentrations in the right and left liver lobe samples in LCu GCN sheep. Liver Cu concentrations in SHC sheep were not influenced by treatment. Future research examining the impact of breed and Cu supplementation on the molecular mechanisms associated with Cu absorption, storage, and excretion is warranted.

PSIX-28 Optimization of feeding trial length for evaluating feed efficiency in sheep

Abstract Feed efficiency tests are well established for beef cattle, but testing for sheep remains rare due to the lack of appropriate equipment and standardized protocols. To explore the optimum trial length for evaluating feed efficiency in sheep, freshly weaned Rideau Arcott ewe lambs [n = 80; 4to 5 mo of age and body weights (BW) of 16 to 25 kg] were enrolled in a 65-d feeding trial, following a 20-d adaptation period. A mixed ration containing barley gain and protein supplement pellets were offered twice daily, and lambs had ad libitum access to feed, water and bedding straw during the trial period. Daily feed intake of individual lambs was monitored with Vytelle SENSE feed bunks, BW was recorded biweekly, as well as on two consecutive days at the start and end of the trial. Lambs that had died or had abnormal growth patterns from sickness were removed, resulting in 62 lambs remaining in the final dataset. Optimum trial length for measuring feed intake (DMI) and average daily gain (ADG) were evaluated with R Software (v. 4.3.3) via a post-hoc analysis of constructing shortened trial lengths from the regular test. The DMI and ADG values from the shortened trial datasets were compared with those from regular trial days with correlation (Pearson and Spearman tests) and linear regression analyses. There were 64 shortened trial lengths for DMI by 1 d increments, and 15 sub-datasets for ADG consisting of trial lengths between every two BW measurements. Residual feed intake (RFI), residual average daily gain (RADG), and residual intake and BW gain (RIG) were calculated for and compared between the regular trial length (65 d) and favorable shortened trial lengths based on DMI and ADG evaluations. Correlation, regression and agreement analyses were used to determine the optimum trial lengths for RFI, RADG and RIG evaluations. Results showed that DMI and ADG measurements could be shortened to 42 (r > 0.95, R2 > 0.90, β > 0.95, P < 0.001) and 56 d (r > 0.96, R2 > 0.93, β > 0.96, P < 0.001), respectively. Additionally, trial length for RFI, RADG, and RG evaluations could be reduced to 56 d (r > 0.95, R2 > 0.91, β > 0.95, CCC > 0.95, P < 0.001), primarily due to the trial length requirement for accurate ADG measurement. Reducing the duration of trials for evaluating feed efficiency in sheep not only reduces testing costs, fostering greater uptake among sheep producers, but also allows for the evaluation of more lambs annually, thereby enhancing the overall productivity and profitability of the sheep industry.

284 The influence of growth promoting implants at weaning with different supplementations levels on growth performance and ovarian parameters in developing beef heifers

Abstract Administration of a pre-weaning growth promoting implant in beef heifers in Southwestern rangelands can improve growth; however, the effect of administering a second growth promoting implant after weaning on growth and ovarian parameters is unknown. The objective of this study was to determine the effect of supplement level when heifers were administered a second Synovex-C implant at weaning on growth and ovarian parameters. At 2 mo of age heifers (n = 30) were randomly assigned to receive one of three implant treatments: 1) non-implanted (CON), 2) Synovex-C implant at 2 mo of age (BIMP), or 3) Synovex-C implant at 2 and 8 mo of age (WIMP). At 8 mo heifers were randomly assigned to one of two supplement levels (High or Low); thus, creating six treatment groups: High CON (n = 5), Low CON (n = 5), High BIMP (n = 5), Low BIMP (n = 5), High WIMP (n = 5), and Low WIMP (n = 5); assigned in a complete randomized design with a 3 x 2 factorial. Heifers were individually fed supplement three times per week for 25 wk (High 1.26 kg·heifer⁻¹·d⁻¹and Low 0.68 kg·heifer⁻¹·d⁻¹of a 32% CP cube) with refusals weighed back after each feeding. Body weights (BW) were recorded biweekly and grouped in 4 periods (wk 0, 2 to 4, 6 to 14, and 16 to 25). At the end of the supplementation period heifers underwent bilateral ovariectomies. Body weight, height, and length of each ovary was recorded. Surface antral follicles were counted on both ovaries and recorded. Length of the largest follicle was recorded, and follicular fluid (FF) was collected for analysis of estradiol and progesterone concentrations. Ovarian and follicular measurements were analyzed using MIXED procedures in SAS. Average daily gain (ADG) and BW were analyzed as repeated measures using MIXED procedures in SAS. Supplement level × implant interaction tended to influence BW (P = 0.09). Period 4 had increased ADG compared with periods 2 and 3 (P < 0.0001). High heifers had increased ovarian length compared with Low heifers (P = 0.03) and implant tended to increase ovarian length (P = 0.09) compared with CON. Supplement level tended to influence diameter of the largest follicle (P = 0.09). Progesterone FF concentrations tended to be reduced in High heifers compared with Low heifers (P = 0.09). In conclusion, administration of a second Synovex-C implant at weaning did not impact growth performance; however, supplement level tended to hinder follicular parameters.

PSII-1 Weaning as prenatal stress: preliminary study on indicators of calf resiliency

Abstract Maternal stressors have been reported to alter fetal development in many species. During pregnancy beef cattle are subjected to different potential stressors, such as weaning their current offspring, as part of beef production practices. The objective of this study was to investigate the relationship between weaning method as a prenatal maternal stress and the effect on offspring resiliency. Multiparous cows were weaned of their calves in the fall of 2022 using either abrupt (A), fenceline (F), or nose-flap (N) weaning methods (n = 30 per group). Calves born from these cows the following spring (2023) were followed for birthweights, morbidity, and mortality. Mean estimated fetal age at exposure was 126 d (range 66 to 219 d) using breed averages for gestational length. Cognitive tests were performed at 2 mo of age using an outdoor arena to continuously monitor calves during 2 min of initial isolation, 2 min exposed to a novel object, and 1 min of exposure to a human in the arena. Tests were performed sequentially, and treatments were balanced across days. Prenatal exposure to A was associated with a 74.8 (2.5 to 2,237.3, P < 0.01) and 21.5 (1.2 to 385.7, P = 0.03) times increase in the odds of calves being stillborn or failure to thrive within 24 h of birth compared with F or N, respectively. There was no difference in morbidity or mortality during d 1 to 60. Birthweights were available on one-half of the calves from each group and showed no statistical difference; however, there was a 4.53 kg numerical difference between A and N groups. Behavioral data from a subset of 36 calves (A = 14, F = 11, and N = 11) was assessed for time spent standing, moving, exploring, duration in the open center vs. perimeter of the arena. There was a tendency for A exposed calves to spend more time in the perimeter after being confronted with a novel object compared with N exposed calves (mean difference of percent of total test time in perimeter from isolation to novel object test: A = 24.0 ± 23.9 %, N = -2.9 ± 22.1 %, P = 0.08). Fenceline exposed calves spent more time moving during initial isolation than either abrupt or nose-flap (69.3 ± 14.7 %, 50.6 ± 11.9 %, and 69.9 ± 17.8 % for A, F, N, respectively (P = 0.01 for A vs F and F vs N). These behavioral and physiological indicators support a potential divergence in survivability and coping mechanisms associated with prenatal exposure to different weaning methods. Future research will evaluate different dimensions of cognitive performance as well as increasing sample size.

68 Wildfire smoke simulations and the effects of smoke exposure on cattle acute phase protein response

Abstract The incidence of and acreage burned by wildfires are globally increasing, with predictions of more devastating fires in the future. The impacts of wildfire smoke exposure on have been of research interest over the years, although the scope of the literature is limited. Evaluating the effects of wildfire smoke exposure is challenging because of the unpredictability of fires, limiting the ability of researchers to evaluate this phenomenon. For this study, a wildfire smoke simulation was created to evaluate the effects of smoke exposure on beef cattle health, performance, and behavior. Heifers [n = 8 Angus x Hereford; body weight (BW) = 532 kg; 8 mo of age) were acclimated to individual pens in a completely closed barn for 7 d (d -7 to -1). Heifers were maintained in the barn for 36 d and exposed to wildfire smoke simulation for 7 consecutive days (d 0 to 7) while inside the barn. Heifers were individually fed alfalfa hay ad libitum, and feed intake was recorded daily. Health scores were collected daily from each heifer by 4 trained technicians, and blood samples were collected weekly for evaluation of acute phase proteins, cytokines, hormones, and hematology. Heifer behavior was recorded continuously using 4 cameras for the length of the study. Air quality was monitored daily every 1 min, using 2 air quality monitors. Preliminary data were analyzed using MIXED procedure of SAS. Heifers were considered the experiment unit serving as its own control, where variables were analyzed over time. Significance was set at P ≤ 0.05. Air quality, assessed with PM2.5, changed over time (P < 0.0001), reaching a daily average of 159 µg/m3 during the smoke simulation period. Although the air quality daily average was above the EPA standard (35 µg/m3), the smoke dissipated during the day, leading to wide variation in the 24 h-cycle (7.60 to 433 µg/m3; P < 0.0001), which might not truly represent air quality conditions during wildfires. Regardless, heifer plasma ceruloplasmin concentration increased over time (P = 0.05), reaching a peak during smoke exposure (29 mg/mL), which was maintained (P = 0.39; 27 mg/mL) for 1 wk post-smoke exposure before returning to nadir (23 mg/mL). An increase in acute phase proteins stimulated by smoke exposure has been observed in cattle naturally exposed to wildfires. Therefore, exposure to wildlife smoke might elicit an inflammatory response, potentially leading to reduced cattle performance, which could be accompanied by changes in behavior. This research was supported by the intramural research program of the USDA-NIFA, Award #2023-68008-39173.

24 Maternal supplementation with different sources of trace minerals to beef cattle and its effects on postweaning responses of the offspring

Abstract The goal of this trial was to evaluate the effects of different sources of trace minerals on fetal programing and their impact on cow reproductive and postweaning offspring performance until slaughter. Seventy-two non-lactating, pregnant Angus cows [initial body weight (BW) = 637 ± 13 kg; body condition score (BCS) = 5.5 ± 0.07; and age = 6.1 ± 0.57; exposed to artificial insemination (AI) = 54 and bull = 18] were ranked by BW and BCS and assigned to receive a supplement containing: 1) Cu, Mn, and Zn from sulfate source (INR; n = 24), 2) Cu, Mn, and Zn from organic source (ORG; n = 24), or 3) Cu, Mn, and Zn from hydroxychloride source (HXD; n = 24). From d 0 to calving, cows remained on the same pasture and were fed individually three times a week. After calving, pairs were assigned to the general herd management, including inorganic mineral supplementation. Calves were weaned at 6 mo of age and were managed as a single group on a backgrounding period for 85 d. Calf blood samples were collected on d -15, 0, 4, 8, 15, 20, and 28 relative to weaning to evaluate stress-related markers. After this period, calves were fed to finish in a commercial feedyard. Cattle were then harvested, and carcass data were recorded. Though not the focus of this trial, there was a numerical improvement (P = 0.22) in overall subsequent pregnancy rate for the HDX (92.1%) compared with the ING (74.3%) and ORG (75.2%) cows. Also, the HDX had a tendency (P = 0.07) for improvement in liver Cu status compared with the other treatments. At weaning, no treatment differences were detected (P ≥ 0.88) in calf weaning BW and average daily gain from weaning to feedyard receiving. There were no differences (P ≥ 0.22) in the blood stress-related enzymes and metabolites. However, there was a tendency for a decrease in plasma haptoglobin at day 15 post-weaning (P = 0.07) for the calves from HDX supplemented cows relative to other treatments (Figure 1). Which might indicate potential amelioration of inflammation for the calves from cows supplemented with HDX trace minerals during pregnancy. Feedyard growth performance were similar (P ≥ 0.35) across treatments for the offspring (Table 1). No treatment effects were detected (P ≥ 0.17) for carcass traits between treatments (Table 2). Overall, different sources of trace minerals supplemented to late gestating beef cows yield similar effects on offspring performance from weaning and background period until slaughter, whereas a potential amelioration of inflammation was observed in calves born to HDX cows.

40 The gut microbiota modifies host-parasite interactions

Abstract It is well documented that parasitic infections induce a profound change in the structure and function of host gut microbiota, likely due to infection-associated perturbations in the gut microenvironment. However, the mechanisms remain largely unknown. Here we aim to understand how the gut microbiota is modified by host-parasite relationships or vice versa using an integrated multi-omics analysis in a swine-Ascaris infection model. Female pigs (n = 30; 6 to 8 mo of age) were randomly divided into three groups (n = 10 per group). One group served as normal uninfected controls (NU); the remaining 20 pigs were inoculated per os with ~10,000 infective A. suum eggs; and the infection was allowed to progress for 35 d post-inoculation (dpi). At 21 dpi, one of the infected groups (IP) was treated with a single daily dose of an anthelmintic drug, Panacur, for three consecutive days while the other infected pigs remained untreated (IU). At necropsy, intestine tissue, serum and fecal samples were collected for untargeted metabolome analysis using UPLC-MS/MS and the fecal microbiota was characterized using full-length 16S rRNA gene-based sequencing with DADA2. Fecal and serum metabolites were categorized for their origin using MetOrigin. An integrated multi-omics analysis was performed using DIABLO algorithms and NetCoMi networking tools. Our results showed that A. suum worms were well developed in pigs from the IU group, which harbored a significantly reduced microbiota alpha diversity (Simpson, P < 0.005) compared with NU. The infection altered the abundance of at least 17 bacterial species/strains, including multiple butyrate-producing Clostridium spp., such as C. butyricum. The infection also dysregulated 51 fecal metabolites, including microbiota-derived metabolites such as glutaric acid and p-Cresol sulfate, and succinate of mixed origin. Moreover, the anthelmintic treatment was efficacious and eliminated all worms from the gut. Nevertheless, 11 pathways of both host and microbiota origin were significantly enriched in the gut of pigs from the IP group, including peptidoglycan biosynthesis, histidine metabolism (in both feces and serum), and primary bile acid biosynthesis, suggesting the infection-induced alterations may not be transient. In conclusion, the host microbiota modified swine-Ascaris interactions via three different mechanisms. First, microbiota-derived metabolites directly regulate host gene expression, which in turn affects host physiology and immune responses. Second, plasticity of the gut microbiota allows the exploitation of the niche differentiated upon infection, resulting in blossom of certain strains in the gut of post-treated animals. Lastly, the host microbiota is likely one of the key determinants of parasite gut microbiota, indirectly exerting its effect on parasite physiology and nutrition. Further studies aiming to understand reciprocal yet complex relations between the gut microbiota, the host, and parasites (including parasite gut microbiota) will be conducive to the design of next-generation functional anthelmintics.

Choosing the optimal combination of lungs lobe evaluation during focused pulmonary ultrasonography in calves

Bovine respiratory disease (BRD) poses significant challenges on beef and dairy farms, impacting mortality rates, animal welfare, and production efficiency. Although pulmonary ultrasonography is highly sensitive and specific for monitoring lung lesions and diagnosing BRD, its practical application could be optimized by focusing on the most commonly affected lung lobes. This study first evaluated the efficacy of focused lung ultrasonography for diagnosing BRD in calves, examining individual lung lobes and their associations versus the extensive lung scanning under various disease prevalence scenarios. Then, the relationship between individual and combined clinical respiratory signs vs lung consolidation was analyzed. In a combined analysis, 193 Holstein calves from a longitudinal study and 112 Angus calves from a cross-sectional study underwent a total of 1265 complete bilateral thoracic ultrasonographic evaluations from 1 to 6 mo of age. Then, it was assessed the agreement and sensitivity of specific lung lobe combinations compared with the findings from total lung ultrasonography. The Classification and Regression Tree (CART) algorithm was used to suggest an optimal examination sequence, and logistic regression was applied to associate specific clinical signs with the presence of lung consolidation adjusting for breed and calf age. Findings reveal that the most sensitive areas are cranial (K: 0.867; Se: 84.7%) and the caudal (K: 0.433; Se: 40.3%) portions of the right cranial lobe, the caudal portion (K: 0.235; Se: 20.6%) of the left cranial lobe, and the middle lobe (K: 0.25; Se: 22%). The optimal lobe combinations for focused lung ultrasonography were identified as the right cranial lobe paired with either the left cranial lobe or the middle lobe. Focused techniques achieved sensitivity over 94% and maintained good agreement. Using these focused techniques were relatively robust to various true lung consolidation scenarios. CART analysis recommended initiating examinations with the right cranial lobe, proceeding to the left cranial lobe, and concluding with the middle lobe. While spontaneous cough was linked to pneumonia presence, reliance on a single clinical sign is not advised due to low sensitivity (26.8%) and high specificity (85.4%); it should merely prompt further ultrasound assessment. In conclusion, focused lung ultrasonography, especially utilizing the right cranial lobe in conjunction with the left cranial lobe or the middle lobe, emerged as effective strategies for focused pulmonary ultrasonography, preserving the accuracy of the results.

Effects of Vitamin D-3 Supplementation During Pregnancy and Lactation on Maternal and Infant Biomarkers of Environmental Enteric Dysfunction, Systemic Inflammation, and Growth: A Secondary Analysis of a Randomized Controlled Trial

BackgroundEnvironmental enteric dysfunction (EED) is an acquired, subclinical state of intestinal inflammation common in children and adults in low-income and middle-income countries. Although vitamin D-3 supplementation has purported anti-inflammatory properties, its ability to ameliorate biomarkers of EED remains unclear. ObjectivesThis study aimed to examine the effects of maternal vitamin D-3 supplementation during pregnancy and lactation on biomarkers of EED, systemic inflammation, and growth in women living with HIV and their infants in Dar es Salaam, Tanzania. MethodsWe conducted subgroup analyses among randomly selected mothers (n = 720) and infants (n = 365 at 6 wk of age, and n = 266 at 6 mo of age) who participated in a randomized, triple-blind, placebo-controlled trial of daily maternal 3000 IU vitamin D-3 supplementation from the second trimester of pregnancy until 1 y postpartum. Biomarkers of EED (soluble CD14 and intestinal fatty acid-binding protein), systemic inflammation (C-reactive protein and α1-acid glycoprotein), and growth factors (insulin-like growth factor 1 and fibroblast growth factor 21) were measured via the Micronutrient and Environmental Enteric Dysfunction Assessment Tool. Anti-flagellin and anti-lipopolysaccharide immunoglobulins were measured via enzyme-linked immunosorbent assay. Comparisons by randomized treatment arm were performed using ordinary least squares regression models with log2-transformed biomarkers. ResultsAt 32 wk of gestation, intestinal fatty acid-binding protein (β: −0.19; P = 0.03) and α1-acid glycoprotein (β:−0.11; P = 0.04) were significantly lower in mothers in the vitamin D-3 group than those in mothers in the placebo group. At 6 wk of age, insulin-like growth factor 1 (β:−0.31; P = 0.03) was significantly lower in infants whose mothers were in the vitamin D-3 group than that in infants whose mothers were in the placebo group. ConclusionsVitamin D-3 supplementation during pregnancy and lactation reduced selected EED and systemic inflammation biomarkers among women living with HIV. While the effects of maternal vitamin D-3 supplementation do not appear to extend to infants, there may be an effect on growth factors.This trial was registered at clinicaltrials.gov as NCT02305927 (https://clinicaltrials.gov/study/NCT02305927).

Immunoprophylaxis failure and vaccine response in infants born to mothers with chronic hepatitis B infection in Djibouti.

In endemic areas, vertical transmission of hepatitis B virus (HBV) remains a major source of the global reservoir of infected people. Eliminating mother-to-child transmission (MTCT) of HBV is at the heart of World Health Organization's goal of reducing the incidence of HBV in children to less than 0.1% by 2030. Universal screening for hepatitis B during pregnancy and neonatal vaccination are the main preventive measures. To evaluate the efficacy of HBV vaccination combined with one dose of immunoglobulin in children born to hepatitis B surface antigen (HBsAg)-positive mothers in Djibouti city. We conducted a study in a prospective cohort of HBsAg-positive pregnant women and their infants. The study ran from January 2021 to May 2022, and infants were followed up to 7 mo of age. HBV serological markers and viral load in pregnant women were measured using aVidas microparticle enzyme-linked immunosorbent assay (Biomérieux, Paris, France) and the automated Amplix platform (Biosynex, Strasbourg, France). All infants received hepatitis B immunoglobulin and were vaccinated against HBV at birth. These infants were closely monitored to assess their seroprotective response and for failure of immunoprophylaxis. Simple logistic regression was also used to identify risk factors associated with immunoprophylaxis failure and poor vaccine response. All statistical analyses were performed with version 4.0.1 of the R software. Of the 50 pregnant women recruited, the median age was 31 years, ranging from 18 years to 41 years. The MTCT rate in this cohort was 4% (2/50) in HBsAg-positive women and 67% (2/3) in hepatitis B e antigen-positive women with a viral load > 200000 IU/mL. Of the 48 infants who did not fail immunoprophylaxis, 8 (16%) became poor responders (anti-HB < 100 mIU/mL) after HBV vaccination and hepatitis B immunoglobulin, while 40 (84%) infants achieved a good level of seroprotection (anti-HB > 100 mIU/mL). Factors associated with this failure of immunoprophylaxis were maternal HBV DNA levels (> 200000 IU/mL) and hepatitis B e antigen-positive status (odds ratio = 158, 95% confidence interval: 5.05-4958, P < 0.01). Birth weight < 2500 g was associated with a poor immune response to vaccination (odds ratio = 34, 95% confidence interval: 3.01-383.86, P < 0.01). Despite a failure rate of immunoprophylaxis higher than the World Health Organization target, this study showed that the combination of immunoglobulin and HBV vaccine was effective in preventing MTCT of HBV. Therefore, further studies are needed to better understand the challenges associated with immunoprophylaxis failure in infants in Djibouti city.

COMPLICATIONS OF MECHANICAL VENTILATION IN CHILDREN UP TO 12 Y OF AGE

Objective: Mechanical ventilation has been proven to be lifesaving and has significantly reduced mortality in the pediatric population. Despite its life-saving advantages, mechanical ventilation is associated with complications. The study aimed to assess the complications of mechanical ventilation in children up to 12 y of age admitted to the intensive care unit. Methods: The present descriptive, observational, cross-sectional study was conducted on 165 children aged between 0 to 12 y, who were mechanically ventilated for&gt;48 h. Patients were observed daily until the desired result was achieved and were checked to look for complications or negative effects of mechanical ventilation. Results: The majority of subjects belonged to&lt;1 mo of age (77.58%) whereas the maximum number of patients were male (64.24%). In 77.58% of patients, the indication for mechanical ventilation was respiratory failure. The duration of ventilation in 62.43% of patients was&gt;7 d. A total of n=62 (37.58%) patients had ventilator-associated complications. The most common complication was ventilator-associated pneumonia (n=30, 48.38%). The mean hospital stay was found to be 22.88±7.96 d. Whereas the mean hospital stay in patients without complications was significantly less compared to patients with complications (18.57±10.09 d vs 27.19±5.83 d, P=0.00015). The mortality rate was found to be 47.27%. Conclusion: Respiratory cause was the most common indication for mechanical ventilation. The most common complication was ventilator-associated pneumonia. The subjects with complications had prolonged hospital stays.

Provision of choline chloride to the bovine preimplantation embryo alters postnatal body size and DNA methylation†.

Choline is a vital micronutrient. In this study, we aimed to confirm, and expand on previous findings, how choline impacts embryos from the first 7days of development to affect postnatal phenotype. Bos indicus embryos were cultured in a choline-free medium (termed vehicle) or medium supplemented with 1.8mM choline. Blastocyst-stage embryos were transferred into crossbred recipients. Once born, calves were evaluated at birth, 94 days, 178 days, and at weaning (average age = 239 days). Following weaning, all calves were enrolled into a feed efficiency trial before being separated by sex, with males being slaughtered at ~580 days of age. Results confirm that exposure of 1.8mM choline chloride during the first 7 days of development alters postnatal characteristics of the resultant calves. Calves of both sexes from choline-treated embryos were consistently heavier through weaning and males had heavier testes at 3 months of age. There were sex-dependent alterations in DNA methylation in whole blood caused by choline treatment. After weaning, feed efficiency was affected by an interaction with sex, with choline calves being more efficient for females and less efficient for males. Calves from choline-treated embryos were heavier, or tended to be heavier, than calves from vehicle embryos at all observations after weaning. Carcass weight was heavier for choline calves and the cross-sectional area of the longissimus thoracis muscle was increased by choline.

Beneficial effects of dietary omega 3 polyunsaturated fatty acids on offspring brain development in gestational diabetes mellitus

Various mechanisms through which maternal diet influences offspring brain development in gestational diabetes mellitus (GDM) remains unclear. We speculate that prenatal omega 3 fatty acids will improve the levels of brain neurotrophins and vascular endothelial growth factor (VEGF), an angiogenic factor leading to improved cognitive performance in the offspring. GDM was induced in Wistar rats using streptozotocin. They were assigned to either control, GDM or GDM+O (GDM + omega-3 fatty acid supplementation). The offspring were followed till 3 mo of age and cognitive assessment was undertaken. Data analysis was carried out using one-way ANOVA followed by LSD test. GDM induction increased (p < 0.01) dam glucose levels and lowered brain derived neurotrophic factor (BDNF) levels (p = 0.056) in the offspring at birth. At 3 months, GDM group showed significantly lower levels of neurotrophic tyrosine kinase receptor-2 (NTRK-2) and VEGF, lower mRNA levels of NTRK-2 and cAMP response element-binding protein (CREB) (P < 0.05 for all) as compared to control. The GDM offspring had a higher escape latency (p < 0.01), made lesser % correct choices and more errors (p < 0.05 for both). Prenatal supplementation with omega 3 polyunsaturated fatty acids was beneficial since it ameliorated some of the adverse effects of GDM.

Impact of an objective scoring system on initiation of therapy in patients with International Neuroblastoma Risk Group Staging System (INRGSS) stage MS neuroblastoma: A report from the Children’s Oncology Group.

10003 Background: A subset of children with INRGSS Stage MS neuroblastoma (NBL) may be observed without treatment, while others have rapidly evolving symptoms that can be life-threatening. ANBL1232 adapted a previously developed semi-quantitative objective scoring system (OSS) to assign a numeric value to symptoms and laboratory abnormalities. The goal was to standardize monitoring, therapy initiation, and treatment duration in this cohort. Methods: Patients with newly diagnosed Stage MS NBL were eligible for this prospective trial. An OSS score (OSSS) was assigned at enrollment; the total number was based on scoring in 5 systems: gastrointestinal (GI), respiratory, circulatory, renal, and hepatic. Within the 5 systems, individual clinical and laboratory parameters were scored as not present = 0, mild/moderate = 1 [Grade 2 CTCAEv4.0 adverse event (AE)] or severe = 2 (Grade ≥3 AE). The OSSS was the sum of highest score within each organ system (maximum score: 2 per system, 10 total). Asymptomatic MS patients with an OSSS &lt; 2 who were either &lt; 3 months (mo) of age without hepatomegaly or 3-18 mo of age with favorable biology tumors were eligible for observation without initial treatment. Observed patients underwent monthly physical examinations and laboratory assessments for the first 6 mo following diagnosis. Tumor imaging was performed every 3 mo for 1 year, then every 6-12 mo through 36 mo. An OSSS ≥2 or a protocol-defined increase in primary tumor size prompted initiation of therapy. Results: From July 2014 to February 2021, 89 eligible and evaluable patients with newly diagnosed stage MS NBL enrolled. Among these, 18 (20.2%; 5 male and 13 female) were eligible for observation. Observed patients were older at diagnosis (median age: 2.87 vs. 1.81 mo, p = 0.23) and more likely to have primary tumors without image-defined risk factors (62.5% vs. 30.0%, p = 0.0166) than those assigned to therapy up front. Nearly all observed patients (17/18) had abdominal/adrenal primaries. The initial OSSS was 0 in all observed patients. Median reported observation time was 36 mo (range: 1-36 mo); 13 patients completed all required monthly assessments for the first 6 mo. No patients in the observation cohort required initiation of therapy for an increase in OSSS. One patient with OSSS = 1 at mo 3 had complete GI symptom resolution by mo 5. Conclusions: An OSSS of 0 at diagnosis can aid in identifying a favorable group of patients with stage MS NBL who can be safely observed. No patients in the observation cohort developed evidence of organ dysfunction or OSSS &gt; 1 despite frequent physical examination and comprehensive laboratory testing, suggesting that follow up may be safely liberalized in this population over time. Clinical and laboratory criteria implemented at diagnosis could be used to identify patients requiring prompt treatment. Clinical trial information: NCT02176967 .