Extra-label bisphosphonate (BP) use in juvenile horses is anecdotally reported, primarily for analgesic effects, despite the limited scientific understanding of biologic impacts on skeletally immature horses undergoing exercise. The objective of this study was to determine the effects of clodronate disodium (CD), a form of BP, on endocrine regulators of calcium. Thus, 32 yearling Quarter Horses were stratified by age (500 ± 13 d), body weight (BW; 336 ± 26 kg), sex (n = 16 geldings, n = 16 fillies), and initial bone optical density into 1 of 4 treatment groups for a 168-d trial. The experimental period was divided into 2 exercise phases to model industry standards. Investigators were blinded to treatment, and all horses received iso-volumetric intramuscular injections of either 1.8 mg/kg BW CD (OSPHOS) or saline (placebo) on days 0, 42, 84, and 126. Treatments consisted of control (CON; n = 8), 1-dose (1X; n = 8; day 84), 2-dose (2X; n = 8; day 0, 84), and 4-dose groups (4X; n = 8; days 0, 42, 84, 126). Serum samples were collected, and physical measurements were recorded including BW, wither height, hip height, body length, and heart girth circumference (HG) every 42 d, prior to treatment administration. Serum samples were analyzed for growth hormone (GH), calcitonin, parathyroid hormone (PTH), and ionized calcium (Ca2+). Data were analyzed using MIXED and CORR procedures of SAS. All physical measurements increased over time (P ≤ 0.01) but were not affected by treatment (P ≥ 0.62). Similarly, there was no effect of treatment for GH (P = 0.44), but concentrations tended to decrease over time (P = 0.09). A treatment × day interaction was observed for PTH (P = 0.05) where concentrations increased following a second CD dose. Specifically, concentrations increased on day 84 in 4X and on day 126 in 2X following the second treatment with CD whereas 1X and CON remained unchanged. Despite the increase in PTH, there was no effect on calcitonin (P ≥ 0.33). Ionized calcium concentrations decreased over time (P < 0.01) with no effect of treatment (P = 0.26). Parathyroid hormone was negatively correlated with serum Ca2+ (r = -0.28, P < 0.01), whereas calcitonin was not correlated with serum Ca2+ (r = 0.06, P = 0.48) nor PTH (r = -0.13, P = 0.12). According to these results, CD has no effect on growth morphometrics, but its use transiently increases PTH concentrations after 2 doses.

The objective of this study was to determine hepatic metabolomic variations in goats with a divergent propensity to consume juniper (Juniperus spp.), a terpene containing invasive woody plant. Terpenes are plant secondary compounds which are aversive to herbivory. A 20-year program of genetic selection developed lines of domestic goats with estimated breeding values (EBV) for propensity to consume above (H: EBV = 13.1 ± 0.2) or below (L: EBV = -14.8 ± 0.5) the herd average for juniper in the diet, resulting in an improved likelihood of biological control of juniper at a landscape scale. The question remains, however, what is the “cost of fitness” for animals consuming juniper in terms of animal health and physiology? To examine this question at a cellular level, a metabolomic comparison of liver tissues from the high (H) and low (L) lines of goats was conducted. In 2019, 20 goats (n = 5 of each age and juniper consumption combination) were weighed and harvested. Serum samples and multiple organs (i.e., liver, kidney, heart, spleen, adrenal, testis) were collected, weighed, and preserved for analysis. The initial focus was on the liver, and samples (200 mg) were submitted to Metabolon, Inc. (Morrisville, NC) to identify metabolites by ultra-high-performance liquid chromatography/tandem high resolution/accurate mass spectrometry chromatography methods. Data were analyzed using the 2-way ANOVA procedure of SAS (SAS Inst. Inc., Cary, NC). Animals (df = 16) were the experimental unit. Statistical significance was determined at P ≤ 0.05 and a tendency at 0.05 < P ≤ 0.10. Multiple differences in abundance of lipid pathway metabolites were identified. There was an increased abundance (P < 0.05) of 19 of 19 of the monoacylglycerol (MAG) metabolites in H than L, including 2-arachidonylcylglycerol, an important signaling molecule recognized as a bridge to endocannabinoid and eicosanoid systems. Endocannabinoids N-arachidonoyltaurine, N-linoleoyltaurine, and N-inolenoyltaurine were lower (P < 0.05) in H goats, and similarly N-oleoyltaurine, N-stearoyltaurine, and N-palmitoyltaurine all trended (0.05 < P < 0.10) lower in H goats. Additionally, the eicosanoid 5-keto-ete was lower (P < 0.05) in H goats. These differences in hepatic metabolites fall into a pattern consistent with biochemical pathways involved in tissue regeneration and inflammation mediated by the enzyme, MAG-lipase (MAGL), the rate-limiting enzyme in the degradation of MAGs. Specifically, there was an accumulation of MAGs and depletion of eicosanoids and endocannabinoids in hepatocytes of goats selected to consume juniper. Whether hepatic MAGL activity differed was not directly tested, further investigation is warranted to better understand the environmental and/or genetic influences leading to MAGL inhibition as a cost of fitness.

Background/Objectives: The experience of prenatal stress results in various physiological disorders due to an alteration of an offspring’s methylome and transcriptome. The objective of this study was to determine whether PNS affects DNA methylation (DNAm) and gene expression in the stress axis tissues of mature Brahman cows. Methods: Samples were collected from the paraventricular nucleus (PVN), anterior pituitary (PIT), and adrenal cortex (AC) of 5-year-old Brahman cows that were prenatally exposed to either transportation stress (PNS, n = 6) or were not transported (Control, n = 8). The isolated DNA and RNA samples were, respectively, used for methylation and RNA-Seq analyses. A gene ontology and KEGG pathway enrichment analysis of each data set within each sample tissue was conducted with the DAVID Functional Annotation Tool. Results: The DNAm analysis revealed 3, 64, and 99 hypomethylated and 2, 93, and 90 hypermethylated CpG sites (FDR < 0.15) within the PVN, PIT, and AC, respectively. The RNA-Seq analysis revealed 6, 25, and 5 differentially expressed genes (FDR < 0.15) in the PVN, PIT, and AC, respectively, that were up-regulated in the PNS group relative to the Control group, as well as 24 genes in the PIT that were down-regulated. Based on the enrichment analysis, several developmental and cellular processes, such as maintenance of the actin cytoskeleton, cell motility, signal transduction, neurodevelopment, and synaptic function, were potentially modulated. Conclusions: The methylome and transcriptome were altered in the stress axis tissues of mature cows that had been exposed to prenatal transportation stress. These findings are relevant to understanding how prenatal experiences may affect postnatal neurological functions.

The interactive responses of cattle genetics and the rumen microbiome (G×M) govern variations in the feed efficiency and methane emissions, which subsequently impact cattle productivity and their environmental footprint. Modulation of the rumen microbiome can be done through dietary supplementation, such as with the antimicrobial ionophore monensin, which offers a pathway to favorably alter metabolic outcomes. However, the limited data on breed-specific microbiome shifts in response to dietary changes restrict the understanding of the impacts of G×M on fermentation and nutrient utilization. The objective of the study was to determine the effect of a monensin-fed diet on the ruminal microbiome and the short-chain fatty acid (SCFA) profile of temperate and tropically adapted cattle breeds. A total of 10 steers each of the Angus, Brahman, and F1 (Angus × Brahman) breed types were fed forage ± a monensin ionophore supplement. Ruminal fluid samples were collected during four 21-day periods (one equilibrium and three treatments). At the conclusion of each period, the SCFAs were analyzed via gas chromatography. The microbiome profiles were analyzed through DNA extraction, quantitative PCR (qPCR) assays, and sequencing to evaluate the G×M interactions. SCFA analysis showed a decrease in the acetate/propionate ratio ( p = 0.001) across all breed types under monensin treatment. However, breed type variations were evident, as the total SCFA concentrations were lower only in the Brahman steers that consumed monensin. The qPCR assays indicated significantly lower ruminal methanogen contents ( mcrA gene; p < 0.01) and a reduced methanogen/prokaryote ratio (MPR; p < 0.001) in monensin-fed steers compared with the control. A treatment-by-breed interaction was observed for the fungi/prokaryote ratio (FBR; p = 0.003), with only F1 steers on the monensin diet showing a lower FBR than those on the control diet. The permutational analysis of variance (PERMANOVA) and beta diversity analyses demonstrated significant differences in the ruminal microbiome structure between the control and the monensin-treated groups for both prokaryotic and fungal communities. Several amplicon sequence variants (ASVs) within the genera Faecalimonas , Streptococcus , and Prevotella showed variable abundance among breeds in response to monensin treatment, confirming the influence of (G×M) interactions on the microbiome structure. This study established the potential of dietary supplementation with an antimicrobial ionophore (monensin) to modulate the rumen microbiome structure, alter the metabolic profiles, and reduce methanogens while emphasizing the need for breed-specific dietary strategies due to the influence of G×M interactions.

As the amygdala is associated with fear and anxiety, it is important to determine the potential effects of gestational stressors on behavior and stress responses in offspring. The objective of this study was to investigate the effects of prenatal transportation stress on amygdala gene expression in 25-day-old Brahman calves, focusing on sex-specific differences. Amygdala tissue samples from prenatally stressed (PNS) and control bull and heifer calves were analyzed using RNA sequencing. A thorough outlier detection process, utilizing visual inspection of multidimensional scaling plots, robust principal component analysis, and PCAGrid methods, led to the exclusion of 5 of 32 samples from subsequent analyses. Differential expression analysis revealed no significant treatment differences between the control and PNS groups within either sex. However, sex-specific differences in gene expression were identified in both the control and PNS groups. The control group showed seven differentially expressed genes between sexes, while ten were identified between PNS males and females, with seven located on the X chromosome. Among these was the ubiquitin-specific peptidase 9 X-linked gene, which plays a role in neurodevelopmental pathways. When comparing males to females, regardless of treatment, a total of 58 genes were differentially expressed, with 45 showing increased expression in females. Gene enrichment analysis indicated that many differentially expressed genes are associated with infectious disease-related pathways. Future research should explore amygdala size and functional responses to various postnatal stimuli.

Abstract The non-nitrogenous bisphosphonate clodronate disodium (CD) inhibits bone resorption and is approved for horses ≥ 4 yr of age. Extra-label use in juvenile exercising horses is a concern due to potential interference with normal bone growth and development. The objective was to determine the effects of single and repeated doses of CD on bone optical density (radiographic bone aluminum equivalence; RBAE) and lameness score (LS) in juvenile, exercising horses. Quarter Horses [n = 32 (16 geldings, 16 fillies); 500 ± 13 d of age; body weight (BW) = 336 ± 26 kg]) were used to test the hypothesis that horses receiving CD would have greater RBAE and reduced LS, and additional doses of CD would accentuate these effects. In a 168-d trial, horses were housed in individual stalls, and fed 1% BW/d concentrate and ad libitum Coastal bermudagrass hay. Horses were exercised 5 d/wk following a phase-based progressive workload using a free stall exerciser; Phase I (d 0 to 84) mimicked sales preparation whereas Phase II (d 85 to 168) simulated early training. Horses were stratified by age, BW, sex, and initial RBAE into control (CON; n = 8), single dose CD (1X; d 84; n = 8), 2-doses CD (2X; d 0 and d 84; n = 8), and four-doses CD (4X; d 0, d 42, d 84, d 126; n = 8). On injection d (0, 42, 84, and 126), horses were administered either 1.8 mg/kg BW CD (OSPHOS) or isovolumetric saline. On d 0, 84, and 168, dorsal-palmar and lateral-medial radiographs of the left third metacarpus and metatarsus were captured. An aluminum step wedge was included in each image and raw images were analyzed (Quantity One Basic, BioRad) to determine total bone RBAE at 1 cm distal to the nutrient foramen. On d 0 and d 168, horses were evaluated by a veterinarian unaware of treatment group and assigned a LS according to the American Association of Equine Practitioners Lameness Scale. The RBAE and LS data were analyzed via PROC MIXED and PROC GENMOD, respectively, in SAS. For each view, RBAE increased from d 0 to d 84 and remained increased to d 168 (P ≤ 0.02), regardless of treatment, likely due to progressing exercise protocol. On d 0, 29 horses were LS 0, 1 horse was LS 1, and 2 horses were LS 2; LS did not differ among treatment groups (P = 0.61). On d 168, 5 horses were LS 0, 13 horses were LS 2, 11 horses were LS 3, and 1 horse was LS 4; LS did not differ among treatments (P = 0.16). Based on these results, the hypothesis that single or repeated CD administration would increase RBAE and decrease lameness in juvenile, exercised Quarter Horses was rejected. Funding: AFRI#2021-67015-34079

Abstract Prenatal stress (PNS) and early life adversity have been linked to epigenetic changes in the nervous, immune, and endocrine systems in various species. Previously, we reported that PNS calves had greater serum concentrations of ACTH and cortisol, were more temperamental, and had differential methylation of leukocyte DNA. The purpose of this study was to determine whether prenatal transportation stress differentially affected gene expression in the adrenal gland of calves. Mature Brahman cows inseminated to a single Brahman sire were assigned to either Control (n = 35; not transported) or PNS (n = 37; 2 h of transportation at 60, 80, 100, 120, and 140 ± 5 d of gestation) group. From some of these cows, 8 Control and 8 PNS bull calves were humanely euthanized at 25 ± 2 d of age. Adrenal glands were obtained, separated into the cortical (AC) and medullary (AM) components, placed into cryovials, snap frozen in liquid nitrogen, and stored at -80°C. Frozen samples (200 mg) were submitted to Novogene Corporation for RNA sequencing analysis on an Illumina Novaseq 6000 platform to generate 150 bp paired-end reads. The reference genome was Bos taurus ARS-UCD1.2. The DESeq2 R package was used for differential gene expression analysis (DEG) and DEGs (P ≤ 0.05, log2FC ≥ 1) were evaluated for gene ontology (GO) subclass terms and Kyoto encyclopedia of genes and genomes (KEGG) enrichment pathways. For the AC DEG comparison, a total of 899 genes were identified, with 641 upregulated and 258 downregulated in PNS calves. The AC DEGs were in the cellular component, molecular function and biological process GO subclasses related to circadian rhythm, lymphocyte proliferation, cytokine regulation, muscle development, and lipid metabolism. The KEGG enrichment analysis identified nitrogen metabolism, cytokine signaling, and circadian rhythm pathways associated with DEG of the AC. For the AM DEG comparison, a total of 1,245 genes were identified, with 745 upregulated and 500 downregulated in the PNS calves. The AM DEGs were in GO subclasses related to skeletal muscle development, antigen processing, and neural crest development. The KEGG enrichment analysis identified cell adhesion, viral infection, cytokine signaling, and amphetamine pathways associated with DEG of the AM. These early results suggest that prenatal stress differentially affects expression of genes of the adrenal cortex and adrenal medulla, which may affect health and growth of calves.Support: USDA NIFA Award No. 2019-67015-29573

Abstract Various managerial, nutritional, and environmental stressors may cause excessive production of reactive oxygen species (ROS) or free radicals which can damage cells and tissues, referred to as oxidative stress. Oxidative stress may impair beef cattle growth performance and product quality. Antioxidant enzymes are important in mitigating increased ROS to prevent oxidative stress, yet little is known about skeletal muscle antioxidant status in beef cattle of different breeds, ages and temperaments. We aimed to test the hypotheses that activities of antioxidant enzymes, glutathione peroxidase (GPx) and superoxide dismutase (SOD), in skeletal muscle would be greater in 1) Angus compared with Brahman steers; 2) longissimus thoracis (LT) compared with trapezius (TRAP) muscles; and 3) calm compared with temperamental animals. Brahman and Angus steers were classified as either calm (n = 13 Angus, n = 12 Brahman), intermediate (n = 11 Angus, n = 10 Brahman), or temperamental (n = 12 Angus, n = 12 Brahman) based on their pen score and exit velocity at weaning. Samples were collected from the LT and TRAP muscles of the steers at 10, 13, and 18 mo of age. Commercial assay kits were used to determine muscle GPx and SOD activities (Cayman Chemical, Ann Arbor, MI). Data were analyzed using linear models in SAS v9.4 with breed, age, temperament, breed × temperament, breed × muscle, and breed × age as fixed effects. Age was included as a repeated effect with animal within breed as the subject. Across muscle groups, Angus had greater GPx and SOD activities than Brahman (P < 0.0001). Additionally, GPx activity increased in both Angus and Brahman steers from 10 to 18 mo (P < 0.0001). In both breeds, the TRAP muscle had greater GPx activity than LT muscle (P < 0.0001). Brahman TRAP muscle also had greater SOD activity than Brahman LT muscle (P < 0.0001) but SOD activity was similar between muscle groups in Angus steers. Neither GPx nor SOD activity differed by temperament group in either breed or muscle group. These data suggest differences in skeletal muscle antioxidant status between Angus and Brahman steers which may mitigate oxidative stress, impacting growth performance as well as product quality at harvest.

Our objective was to determine if there was a cost of fitness associated with selecting Spanish x Boer goats for their propensity to consume above (H) or below (L) the herd average for proportion of juniper (Juniperus spp.) in the diet. Organ weights and metabolic parameters were compared among adult male goats (young [2-year-old] and old [3-5-year-old]) that spent their life grazing pastures containing juniper at the Texas A&M AgriLife Sonora Research Station. In June 2019, body weights were recorded, and serum samples collected by jugular venipuncture from 20 animals (n = 5 of each age and juniper consumption combination) 2 days prior to harvest. At harvest, organ weights (i.e., liver, kidney, heart, spleen, adrenal, testicle, epididymis) were obtained and later analyzed as relative organ weights (organ to body weight ratio). Analysis of variance was used to determine if differences in organ weights (g/kg BW) and serum parameters were detected between young (Y) and old (O), and H and L goats. Body weights (kg) did not differ by treatment group but were greater (P < 0.03) for O (76.0 ± 3.72) than Y (66.3 ± 1.9). Total testicular, epididymal, adrenal, and heart organ weights (g/kg BW) were not affected (P > 0.10) by age nor juniper consumption group. Total kidney weight (g/kg BW) was greater (P < 0.05) in H (2.53 ± 0.09) than L (2.19 ± 0.08) and liver weight (g/kg BW) trended (P = 0.15) in the same pattern, with H (15.80 ± 0.75) greater than L (14.58 ± 0.39). All serum parameters were clinically normal. Serum urea nitrogen (mg/dL) did not differ by treatment (P > 0.1) but was greater (P < 0.004) in O (12.9 ± 1.3) than Y (8.2 ± 0.5). NEFA (mEq/L) was greater (P < 0.02) in H (0.33 ± 0.04) than L (0.26 ± 0.02), but not differ between O and Y. Total globulin (g/dL) was greater (P < 0.007) in L (4.34 ± 0.35) than H (3.40 ± 0.16), and in O (4.29 ± 0.38) than Y (3.45 ± 0.12). Gamma glutamyl transferase was elevated (P < 0.0001) in H (59.2 ± 2.1) versus L (44.3 ± 2.2), and in Y (55.3 ± 2.9) than O (48.2 ± 3.2). In summary, under adequate nutritional conditions, length of exposure (via advancing age) and preference for juniper did not incur an acute cost of fitness in goats. However, the observed metabolic and organ differences indicate that under more challenging chronic conditions (e.g., drought or disease), consumption of monoterpene-defended plants may become problematic. Research to define these eco-physiologic bounds is needed.

The objective of this study was to determine if sire or dam had a stronger impact on age at first parturition of Brahman heifers (n = 833) born between 2000-2021. Typically, in Bos taurus heifers, puberty occurs between 10 to 12 mo of age leading to parturition of the first calf occurring around 24 mo of age. However, in Bos indicus cattle, puberty is achieved between 15 to 17 mo of age leading to a first calf around 36 mo of age. The ability of heifers to achieve pubertal status earlier plays a vital role in reproductive success. For selection purposes, knowing if early pubertal attainment is influenced more by the sire or dam is important for herd management. For this study, to minimize any epigenetic and environmental changes, all heifers originated and were developed at the Texas A&M AgriLife Research Center at Overton. Sire groups (SG) and dam groups (DG) were established based on the number of offspring used in the study. Sire groups were comprised of SG-1 (1+ calves sired; n = 58 sires), SG-2 (5+ calves sired; n = 44 sires), SG-3 (10+ calves sired; n = 31 sires), SG-4 (15+ calves sired; n = 23 sires), SG-5 (20+ calves sired; n = 17 sires), and SG-6 (25+ calves sired; n = 12 sires). Dam groups consisted of DG-1 (1+ calves; n = 489 dams), DG-2 (2+ calves; n = 215 dams), DG-3 (3+ calves; n = 81 dams), DG-4 (4+ calves; n = 38 dams), and DG-5 (5+ calves; n = 9 dams). Statistical analysis (PROC GLM; SAS 9.4) included the fixed effect of sire group (dam group) and all dams (sires) utilized in that grouping. Significance for age at first calving was considered at P < 0.05. Mean separation for age was performed using LSmeans. Sire significantly impacted age at first calving in SG-1 (P = 0.0173) vs dam effect (P = 0.3993; n = 489 dams), SG-2 (P = 0.0159) vs dam effect (P = 0.5476; n = 481 dams), SG-3 (P = 0.0023) vs dam effect (P = 0.2532; n = 439 dams), SG-4 (P = 0.0022) vs dam effect (P = 0.3997; n = 400 dams), SG-5 (P = 0.0002) vs dam effect (P = 0.0602; n = 361 dams), and SG-6 (P = 0.0005) vs dam effect (P = 0.1058; n = 305 dams). The dam impact on age at first calving was never significant in the dam groupings but sires did impact age at first calving in two groups: DG-1 (P = 0.3993) vs sire effect (P = 0.0173; n = 58 sires), DG-2 (P = 0.4823) vs sire effect (P = 0.0173; n = 56 sires), DG-3 (P = 0.3011) vs sire effect (P = 0.3420; n = 49 sires), DG-4 (P = 0.3911) vs sire effect (P = 0.6278; n = 40 sires), and DG-5 (P = 0.3042) vs sire effect (P = 0.9159; n = 23 sires). In summary, evaluation of sire and dam influences on age at first parturition for female offspring demonstrates that the ability to calve at an earlier age is influenced by the sire but not the dam. Further studies into the mechanisms for the transmission of this trait are warranted.

Background Temperament is an important production trait in cattle and multiple strategies had been developed to generate molecular markers to assist animal selection. As nonsynonymous single nucleotide polymorphisms are markers with the potential to affect gene functions, they could be useful to predict phenotypic effects. Genetic selection of less stress-responsive, temperamental animals is desirable from an economic and welfare point of view. Methods and results Two nonsynonymous single nucleotide polymorphisms identified in HTR1B and SLC18A2 candidate genes for temperament were analyzed in silico to determine their effects on protein structure. Those nsSNPs allowing changes in proteins were selected for a temperament association analysis in a Brahman population. Transversion effects on protein structure were evaluated in silico for each amino acid change model, revealing structural changes in the proteins of the HTR1B and SLC18A2 genes. The selected nsSNPs were genotyped in a Brahman population ( n = 138), and their genotypic effects on three temperament traits were analyzed: exit velocity, pen score, and temperament score. Only the SNP rs209984404-HTR1B (C/A) showed a significant association ( P = 0.0144) with pen score. The heterozygous genotype showed a pen score value 1.17 points lower than that of the homozygous CC genotype. Conclusion The results showed that in silico analysis could direct the selection of nsSNPs with the potential to change the protein. Non-synonymous single nucleotide polymorphisms causing structural changes and reduced protein stability were identified. Only rs209984404-HTR1B shows that the allele affecting protein stability was associated with the genotype linked to docility in cattle.

The objective of this study was to determine aspects of liver function in goats with a divergent propensity to consume juniper ( Juniperus spp.), a terpene -containing woody plant. Goats represent a significant contribution to sustainable food production and local economies worldwide. Climate change in arid and semiarid regions has led to a transition of grasslands to woodlands. Goats ( Capra hircus) are adapted to utilize woody plants as a food source; however, herbivory can be limited by plant secondary compounds (e.g., monoterpenes). Estimated breeding values (EBV) have been determined for domestic goats based on their propensity to consume above (H: EBV = 13.1 ± 0.2) or below (L: EBV = −14.8 ± 0.5) the herd average for proportion of juniper in the diet of free-ranging animals. To investigate the physiological and metabolic mechanisms enabling increased intake and tolerance of juniper, H and L adult male Spanish goats within young (2-yr-old) and old (3-5-yr-old) groups that spent their life grazing pastures containing juniper were randomly selected from our research herd. Twenty goats (n = 5 of each age and juniper consumption combination) were weighed and harvested. Serum samples and multiple organs (i.e., liver, kidney, heart, spleen, adrenal, testis) were collected, weighed, and preserved for analyses. With an initial focus on the liver, samples (200 mg) were submitted to Metabolon, Inc. (Morrisville, NC) to identify metabolites by ultra-high-performance liquid chromatography/tandem high resolution/accurate mass spectrometry chromatography methods. Data were analyzed using the PROC MIXED procedure of Statistical Analysis System (SAS Institute Inc., Cary, NC). Goat body weight (BW), relative organ weight (g/kg BW), and serum constituents were analyzed using a model that included age (O, Y), treatment (H, L), and the age x treatment interaction. Animals were the experimental unit and error degrees of freedom = 16. Statistical significance was determined at P ≤ 0.05. Multiple differences in metabolites of the lipid and protein pathways were identified. For example, the relative intensity of 19 monoacylglycerol metabolites was greater (P < 0.05) in H than L goats. This report, however, focuses on the gamma-glutamyl amino acid (GGAA) pathway due to its role in diagnosis of liver dysfunction. Relative liver weight (g/kg BW) was numerically greater (P = 0.15) in H (15.80 ± 0.75) than L (14.58 ± 0.39) goats. Serum gamma glutamyl transferase (U/L) was within the clinically normal range but was greater (P < 0.0001) in H (59.2 ± 2.1) versus L (44.3 ± 2.2), and in Y (55.3 ± 2.9) versus O (48.2 ± 3.2) goats. Of the 18 GGAAs identified from the GGAA super- and sub-pathways, the relative intensities of 11 metabolites were greater (P < 0.05) in liver from H than L; 8 were greater in HY versus LY, and only 2 were greater in OH versus OL goats. The increased expression of serum and liver components of the GGAA pathway for the goats with a positive estimated breeding value for juniper consumption may be indicative of metabolic mechanisms and biomarkers associated with increased tolerance of plant secondary compounds. Texas A&M AgriLife Research. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Bisphosphonates are commonly used to treat and prevent bone loss, but their effects in active, juvenile populations are unknown. This study examined the effects of intramuscular clodronate disodium (CLO) on bone turnover, serum bone biomarkers (SBB), bone mineral density (BMD), bone microstructure, biomechanical testing (BT), and cartilage glycosaminoglycan content (GAG) over 165 days. Forty juvenile sheep (253 ± 6 days of age) were divided into four groups: Control (saline), T0 (0.6 mg/kg CLO on day 0), T84 (0.6 mg/kg CLO on day 84), and T0+84 (0.6 mg/kg CLO on days 0 and 84). Sheep were exercised 4 days/week and underwent physical and lameness examinations every 14 days. Blood samples were collected for SBB every 28 days. Microstructure and BMD were calculated from tuber coxae (TC) biopsies (days 84 and 165) and bone healing was assessed by examining the prior biopsy site. BT and GAG were evaluated postmortem. Data, except lameness data, were analyzed using a mixed-effects model; lameness data were analyzed as ordinal data using a cumulative logistic model. CLO did not have any measurable effects on the skeleton of sheep. SBB showed changes over time (p ≤ 0.03), with increases in bone formation and decreases in some bone resorption markers. TC biopsies showed increasing bone volume fraction, trabecular spacing and thickness, and reduced trabecular number on day 165 versus day 84 (p ≤ 0.04). These changes may be attributed to exercise or growth. The absence of a treatment effect may be explained by the lower CLO dose used in large animals compared to humans. Further research is needed to examine whether low doses of bisphosphonates may be used in active juvenile populations for analgesia without evidence of bone changes.

The beef industry relies on multiple focused segments (e.g., cow-calf, stocker/feeder, and meat packing) to supply the world with beef. Thus, the potential impact of developmental programming on the beef industry needs to be evaluated with regards to the different production traits that drive profitability within each segment. For example, when nutrient restriction of dams occurred early in gestation embryo survival was decreased and the ovarian reserve of heifer progeny was negatively affected. Restriction during mid- to late gestation negatively impacted first service conception rates and pregnancy success of daughters. Even non-nutrient stress has been reported to impact transgenerational embryo development through the male progeny. Primary and secondary muscle fibers form during months two to eight (Days 60-240) of gestation. Therefore, external stimuli (nutrition or environmental) during this window have the potential to decrease the postnatal number of muscle fibers; which has an irreversible impact on animal growth and performance. Nutrient restriction during the last third of gestation resulted in decreased weaning weights, and in some instances decreased dry mater intake, hot carcass weight, and marbling scores. Protein supplementation during late gestation; however, increased weaning weight and ADG to weaning, but progeny of dams restricted in protein in late gestation had greater ribeye area. The importance of developmental programming is recognized; however, its precise application depends on comprehension of its integrated effects across the multiple-focused segments of the beef industry.