Search Results (102)

Maternal undernutrition (MUN) causes severe metabolic disruption in the offspring of mammals. Here we determined the role of histone modification in hepatic gene expression in late-gestation fetuses of nutritionally restricted cows, an established model using low-nutrition (LN) and high-nutrition (HN) conditions. The chromatin immunoprecipitation sequencing results show that genes with an altered trimethylation of histone 3 lysine 4 (H3K4me3) are associated with cortisol synthesis and secretion, the PPAR signaling pathway, and aldosterone synthesis and secretion. Genes with the H3K27me3 alteration were associated with glutamatergic synapse and gastric acid secretion. Compared to HN fetuses, promoter H3K4me3 levels in LN fetuses were higher in GDF15, IRF2BP2, PPP1R3B, and QRFPR but lower in ANGPTL4 and APOA5. Intriguingly, genes with the greatest expression changes (>1.5-fold) exhibited the anticipated up-/downregulation from elevated or reduced H3K4me3 levels; however, a significant relationship was not observed between promoter CpG methylation or H3K27me3 and the gene set with the greatest expression changes. Furthermore, the stress response genes EIF2A, ATF4, DDIT3, and TRIB3 were upregulated in the MUN fetal liver, suggesting involvement of the response in GDF15 activation. Thus, H3K4me3 likely plays a crucial role in MUN-induced physiological adaptation, altering the hepatic gene expression responsible for the integrated stress response and systemic energy metabolism, especially circulating lipoprotein lipase regulation. Full article

Weaning is challenging for dairy calves, frequently resulting in digestive issues. This highlights the importance of implementing appropriate nutritional strategies to enhance gut health and support optimal growth. Postbiotics is a promising alternative to traditional probiotics, conferring health benefits without the risks associated with live bacteria. This study aimed to investigate the effect of dietary supplementation with a postbiotic from dead-cell Limosilactobacillus ingluviei C37 (postbiotic LIC37) on blood biochemical parameters and jejunal epithelium transcriptomic profiles in calves. Fourteen Holstein bull calves were randomly allocated into two groups (n = 7). The control group (CON) received a basic diet, while the postbiotic group (DCLI) was supplemented with 1 g/d of postbiotic LIC37 for 90 days. Blood samples were collected on days 76, 83, and 90, respectively. The jejunal epithelial tissue was obtained from four randomly selected calves per group at day 90 for transcriptome analysis. The results showed that postbiotic LIC37 supplementation reduced globulin, total protein, neutrophil (Neu) levels, and neutrophil-to-lymphocyte ratio (NLR) levels in the DCLI group (p < 0.05). Transcriptomic analysis identified 76 differentially expressed genes (DEGs), with significant upregulation of genes involved in fatty acid metabolism (FABP1), intestinal barrier function (B4GALNT2), and detoxification (GSTA1), alongside downregulation of immune response regulation (FCRLA, FCRL4). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses highlighted enrichment in pathways related to glutathione metabolism, drug metabolism, and vitamin digestion, indicating that postbiotic supplementation improved detoxification, oxidative stress defense, and nutrient absorption in calves. This study provides novel insights into the molecular mechanisms underlying the benefits of postbiotic LIC37 and supports its potential as a sustainable alternative to probiotics in calf nutrition. Full article

Background/Objectives: This study aimed to establish the potential osteotropic effect of pine pollen on bone metabolism in male rats during the development of osteopenia induced by orchidectomy (ORX). We also established the effect of gonadectomy and pine pollen on the characteristics of calf muscles. Methods: This study was conducted using 40 male Wistar rats divided into one sham-operated (SHO) and four ORX groups. The SHO rats and one ORX group (negative control) were treated with physiological saline (PhS). The remaining ORX groups received exclusively testosterone (positive control) and two doses of pine pollen (50 and 150 mg/kg b.w.), respectively. The rats were killed 60 days later and their right tibia and left pelvic limbs were isolated. The tibia was analyzed using densitometry, computed tomography, and a bending machine to determine densitometry, structure, and mechanical properties, respectively. The left pelvic limb allowed for measurements of area, density, and fat tissue in the calf muscle. Results: The dose of 150 mg/kg b.w. inhibited the development of atrophic changes, both in the cortical and trabecular bone tissue. The dose of 50 mg/kg b.w. also has a protective effect on bones but is less pronounced and concerns only the trabecular bone tissue. The higher dose of pine pollen inhibited the catabolism of the calf muscles by maintaining the density and surface area as in the SHO group. It also limited the accumulation of intramuscular and subcutaneous adipose tissue. Conclusions: It is worth emphasizing the osteoprotective effectiveness of pine pollen, especially when administered in larger doses, which demonstrates the possibility of its use in the prevention of the development of osteoporosis in males. Full article

: Negative energy balance (NEB) in dairy cows induces excessive lipolysis, leading to elevated levels of β-hydroxybutyric acid (BHBA), which, when accumulated, can cause liver damage. Rutin (RT), a natural flavonoid with antioxidant and anti-inflammatory properties, has demonstrated potential hepatoprotective effects; however, its ability to mitigate BHBA-induced hepatocellular injury in calves remains unclear. This study first assessed the impact of various BHBA concentrations on oxidative stress in calf hepatocytes, then explored the protective effects and underlying mechanisms of RT, and finally employed untargeted metabolomics to further elucidate RT’s mode of action. The results showed that exposure to 1.2 mM BHBA significantly increased malondialdehyde (MDA), nitric oxide (NO) contents, and reactive oxygen species (ROS) levels, while markedly decreasing glutathione (GSH) content and catalase (CAT) activity compared with the blank control. Notably, pretreatment with 100 μg/mL RT resulted in the greatest increase in GSH contents (180%) compared to BHBA treatment alone, while 150 μg/mL RT led to the most pronounced reduction in MDA contents (220%). Furthermore, BHBA treatment significantly upregulated the expression of Kelch-like ECH-associated protein 1 (Keap1) and downregulated nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO1), and heme oxygenase-1 (HO-1) at both the mRNA and protein levels. These alterations were effectively reversed by pretreatment with 100 μg/mL RT. Non-targeted metabolomics identified 1525 metabolites in total. Based on OPLS-DA, metabolites with a variable importance in projection (VIP) > 1 and p < 0.05 were considered significantly altered. Compared with the blank control, BHBA treatment upregulated 47 metabolites—including 8-hydroxy-2′-deoxyguanosine, 3-hydroxyisovaleric acid, and N-palmitoyl-sphingosine—and downregulated 58 metabolites, such as betaine, linolenic acid, and arachidonic acid. In contrast, RT pretreatment upregulated 207 metabolites relative to the BHBA treatment, including linolenic acid, taurocholic acid, and 4-hydroxybenzoic acid, and downregulated 126 metabolites, including 3-hydroxyisovaleric acid, 8-hydroxy-2′-deoxyguanosine, and pyruvaldehyde. Pathway enrichment analysis indicated that RT alleviated BHBA-induced hepatocyte injury primarily by modulating the fatty acid degradation pathway. In summary, RT mitigated BHBA-induced oxidative stress in calf hepatocytes by regulating the Keap1/Nrf2 signaling pathway and further exerted protective effects through metabolic reprogramming. Full article

Hyperketonemia (HYK) is a common disorder in high-producing dairy cows, resulting in significant economic losses. Defined by elevated beta-hydroxybutyrate (BHB; ≥1.2 mmol/L) without clinical signs, HYK is often considered a gateway disease, predisposing cows to other metabolic and infectious problems. Our objective was to investigate the association between previous lactation risk factors and both BHB concentration and HYK status during the first week postpartum in the subsequent lactation. A retrospective study was conducted using previously collected blood samples from 2336 Holstein multiparous dairy cows from 7 dairy herds, where BHB concentration was measured during the first week postpartum. Data from the previous lactation were extracted from electronic farm records. Log-transformed BHB concentrations and HYK status were each modeled using separate linear mixed models. Both models included the same set of risk factors—lactation, previous lactation total times bred, dry length period, previous lactation days in milk, previous lactation days open, previous lactation days carried calf, previous lactation peak milk production, previous lactation total milk production, previous lactation total milk fat, and previous lactation total milk protein—to investigate their association with these outcomes. Potential confounding variables were offered to the models, and stepwise backward elimination was used to determine which covariates to retain. Significant associations were detected between BHB concentration and dry period length (DDRY), lactation number (LACT), previous lactation total milk protein (TOTP), and previous lactation days open (PDOPN). Inclusive, significant associations were detected between HYK status and previous lactation total milk production (PTOTM), DDRY, LACT, TOTP, and PDOPN. Our results suggest that a dry period longer than 60 days, days open exceeding 130 days, being in their third or greater lactation, and each additional 1000 kg of milk produced in the previous lactation are associated with an increased risk of having high BHB and HYK in the first week postpartum in the subsequent lactation. Full article

Forty multiparous Nellore cows, with an average body weight, body condition score, and gestation days of 533 ± 32 kg, 5.7 ± 0.4 points, and 198 days, respectively, were managed under continuous grazing on a Urochloa decumbens pasture and either received or did not receive 1 kg/day of supplement varying in the levels of inclusion of dried distillers grains (DDG) (Control, 0% DDG, 42% DDG, or 84% DDG) during the last trimester of gestation. The objective was to evaluate the effects of prepartum DDG supplementation on performance, reproduction, fetal development, and calf performance. A quadratic effect of supplementation on BW variation pre- and postpartum was observed (p < 0.05), with cows treated with 42% DDG showing higher BW gain prepartum and low BW loss postpartum. Cows supplemented with 42% DDG had lower levels of non-esterified fatty acids and β-hydroxybutyrate prepartum (p < 0.05). However, body weight-related metrics, such as condition score, carcass traits, and metabolic indicators, varied only by measurement day (p < 0.05). No effect of supplementation was observed on fetal development, calf metabolic profile, milk yield, or postnatal calf performance (p > 0.05). It is recommended to include up to 42% DDG in supplements for beef cows during late gestation grazing on low-quality tropical forage conditions. Full article

Background: Frailty is a state of increased vulnerability to psychosomatic dysfunction associated with aging, with sarcopenia being a major contributing factor. Metabolic-syndrome-related metabolic diseases are recognized as risk factors for sarcopenia. While previous studies have examined the relationship between metabolic disease history or elevated metabolic syndrome indicators and sarcopenia, limited evidence exists regarding the association between metabolic indicators within reference ranges and sarcopenia in the absence of metabolic disease. This study aimed to investigate the relationship between metabolic syndrome indicators within reference ranges and the presence or absence of possible sarcopenia, as well as changes in these indicators over a four-year period, in women aged ≥65 years. Methods: A total of 224 community-dwelling women aged ≥65 years from M City and O Town who participated in health check-ups were included (approval no. 20MH017, 1 October 2020). Data were collected on height, body weight, and metabolic indicators (triglycerides, HDL cholesterol, LDL cholesterol, systolic and diastolic blood pressure, and HbA1c) at baseline and after four years. Physical performance was assessed using calf circumference, grip strength, and the five-time sit-to-stand test. Possible sarcopenia was defined according to AWGS2019 criteria. Results: Higher baseline HDL cholesterol levels were found to be protective against possible sarcopenia. An increase in triglyceride levels over four years was also associated with a reduced likelihood of possible sarcopenia. Conclusions: Maintaining high HDL cholesterol levels and increasing or preserving triglyceride levels may contribute to the prevention of sarcopenia in older women with metabolic indicators within reference ranges. Full article

Bovine viral diarrhea virus (BVDV) remains a major cause of calf diarrhea with substantial economic impacts on global cattle production. While emerging evidence suggests that the host microbiota may modulate viral infection processes, the specific gut microbial alterations induced by BVDV infection require elucidation. This study investigated gut microbiota composition and functional changes in BVDV-infected cows through 16S rRNA sequencing. Following the epidemiological screening of a large Angus cattle herd using RT-PCR, we identified four persistently infected (PI) animals and four BVDV-negative controls. Fecal analysis revealed Firmicutes and Bacteroidetes as dominant phyla in both groups. A significant increase in the Ruminococcus genus was observed in PI cows (p < 0.05), with LEfSe analysis identifying Paludibacter as a BVDV-associated biomarker. The PI group exhibited reduced alpha diversity (Faith’s PD index, p < 0.05) and elevated histidine metabolism pathway abundance compared to controls (p < 0.05). These findings demonstrate that persistent BVDV infection induces structural and functional modifications in the bovine gut microbiota, particularly through the enrichment of specific bacterial taxa and altered metabolic potential. The results provide new insights into virus–microbiota interactions, establishing a foundation for understanding how BVDV infection may influence host physiology through microbial community changes. Full article

This study examined branched-chain fatty acids (BCFAs)’ effects on oxidative stress, energy metabolism, inflammation, tight junction disruption, apoptosis, and Toll-like receptor 4/nuclear factor kappa-B (TLR4/NF-κB) signaling in lipopolysaccharide (LPS)-induced calf small intestinal epithelial cells (CSIECs). Eight groups were used: a control group, an LPS-induced group, and six BCFA treatment groups (12-methyltridecanoic acid (iso-C14:0), 13-methyltetradecanoic acid (iso-C15:0), 14-methylpentadecanoic acid (iso-C16:0), 15-methylhexadecanoic acid (iso-C17:0), 12-methyltetradecanoic acid (anteiso-C15:0), and 14-methylhexadecanoic acid (anteiso-C17:0)) with LPS. The BCFA pretreatments significantly increased CSIEC activity compared to the LPS-induced group, with iso-C14:0 showing the highest activity (89.73%). BCFA reduced Reactive Oxygen Species (ROS) generation and malondialdehyde (MDA) levels and improved the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities and glutathione (GSH) levels. Iso-C16:0 optimized total antioxidant capacity (T-AOC). BCFA enhanced the mitochondrial membrane potential, Adenosine Triphosphate (ATP) enzyme activity, and ATP content, with iso-C14:0 increasing ATP by 27.01%. BCFA downregulated interleukin (IL)-1β, IL-8, tumor necrosis factor (TNF)-α, and interferon (INF)-γ gene expression, reduced IL-6 levels, and increased IL-10 expression. Myeloid differentiation factor 88 (MyD88) mRNA levels were reduced. BCFA alleviated Zonula Occludin (ZO-1), Claudin-1, and Claudin-4 decrease and increased Occludin levels. BCFA mitigated LPS-induced increases in Caspase-3 and BCL2-Associated X (BAX) mRNA levels, reduced Caspase-8 and Caspase-9 expression, and increased B-Cell Lymphoma-2 (BCL-2) mRNA levels. The Entropy Weight-TOPSIS method was adopted, and it was discovered that iso-C15:0 has the best effect. In summary, BCFA supplementation mitigated oxidative stress and enhanced mitochondrial function. BCFA inhibited TLR4/NF-κB signaling pathway overactivation, regulated inflammatory cytokine gene expression, reduced cellular apoptosis, preserved tight junction integrity, and supported barrier function. Full article

This study investigates ferroptosis in the context of peripheral artery disease (PAD), a vascular disease characterized by atherosclerosis of the lower extremities. Muscle atrophy and increased oxidative stress are hallmarks of PAD and correlate with worse clinical outcomes. Given ferroptosis’ association with oxidative stress, we explored its role in PAD myopathy by examining gene and protein markers related to metabolic pathways implicated in ferroptosis using both human PAD patients and cultured myotubes. Intermittent claudication (IC) PAD patients, critical limb ischemia (CLI) PAD patients, and non-PAD controls were recruited for this study. Calf muscle biopsies were analyzed for gene expression using qPCR, and protein levels were determined by Western blotting. Cultured myotubes treated with the ferroptosis inducer erastin provided an in vitro comparison. Results demonstrated upregulation of ferroptosis markers such as lipid peroxidation and PTGS2 gene expression in the muscle of CLI PAD patients compared to controls. Increased expression of ferroptosis-related genes HMOX1, ACSL4, ELAVL1, and Beclin-1 was also observed. Protein analysis showed trends consistent with gene expression in some ferroptosis markers. The increase in ferroptosis markers in CLI PAD patients, particularly in iron metabolism and autophagy pathways, suggests ferroptosis contributes to PAD myopathy. Full article

Most DNA damage caused by oxidative metabolism consists of single lesions that can accumulate in tissues. This review focuses on two classes of lesions: the two 8-oxopurine (8-oxo-Pu) lesions that are repaired by the base excision repair (BER) enzyme and the four 5′,8-cyclopurine (cPu) lesions that are repaired exclusively by the nucleotide excision repair (NER) enzyme. The aim is to correlate the simultaneous quantification of these two classes of lesions in the context of neurological disorders. The first half is a summary of reactive oxygen species (ROS) with particular attention to the pathways of hydroxyl radical (HO^•) formation, followed by a summary of protocols for the quantification of six lesions and the biomimetic chemistry of the HO^• radical with double-stranded oligonucleotides (ds-ODN) and calf thymus DNA (ct-DNA). The second half addresses two neurodegenerative diseases: xeroderma pigmentosum (XP) and Cockayne syndrome (CS). The quantitative data on the six lesions obtained from genomic and/or mitochondrial DNA extracts across several XP and CS cell lines are discussed. Oxidative stress contributes to oxidative DNA damage by resulting in the accumulation of cPu and 8-oxo-Pu in DNA. The formation of cPu is the postulated culprit inducing neurological symptoms associated with XP and CS. Full article

Fifty high-risk bull calves were used in a completely randomized design (ten calves/treatment) to evaluate the optimal period of calcium propionate (CaPr) supplementation following arrival into the feedlot. The variables evaluated were the growth performance, dietary energetics, body fat reserves, serum metabolites, and economic return at day 56 of arrival. Calves, which were weighed at the moment of reception (156.2 ± 1.57 kg off-truck body weight, BW), were received with a 50:50 forage-to-concentrate ratio diet and clean water. At 12 h from reception, they were housed in individual pens during a 56 d feeding period and assigned to treatments consisting of a daily supplementation of a commercial product (Propical^® Dresen Química, SAPI de CV., Mexico City, Mexico) that provided 19 g CaPr/calf for 0, 14, 28, 42, or 56 d following arrival into the feedlot. Compared with the other treatments, the calves receiving CaPr during the initial 42 d had a greater average daily weight gain (p ≤ 0.035) without affecting the dry matter intake (p ≥ 0.24). Thus, the gain efficiency (p ≤ 0.050) and dietary energy utilization were improved (p ≤ 0.046). Rib fat thickness (p ≥ 0.090) and Longissimus lumborum muscle area (p ≥ 0.112) were not affected by the CaPr supplementation, whereas calves showed the greatest values (p ≤ 0.038) to the rump back fat thickness at 42 and 56 days of CaPr supplementation. With the exception of the total albumin (being maximal at day 56 (p ≤ 0.024)) and total cholesterol (which, compared to the controls, was maximal at 28 and 42 d; p = 0.030), the serum metabolic profiles were not affected by the treatments. Using the profit estimated for the control group as a baseline, supplementing CaPr for 42 d yielded a greater net income (USD 34.84 more/calf). CaPr supplementation for more or less than 42 d showed a very similar profit (~USD 6.80/calf). Because the cost of gain was very similar for these treatments and the controls (USD 1.42 vs. 1.46/kg), the positive difference in profit was mediated mainly by an increase in income selling (+USD 13.02/calf) for the CaPr calves. Based on the performance, serum metabolites, and profit, it is concluded that the optimal duration of supplemental CaPr is 42 d. Offering 19 g CaPr during this period enhanced the growth performance, dietary energy, and economic returns. Full article

This study investigated differences in gastrointestinal microbiota and blood metabolomes in calves with different heat stress (HS) responses in the same hot environment. Ten high (H) and ten low (L) HS response preweaning Holstein calves were selected based on their heat stress level (respiratory rate and rectal temperature), jugular vein blood samples and ruminal and fecal samples were collected. Notable variations were observed in the serum levels of heat shock protein 70 (HSP-70) and IL-2 between the two calf groups (p < 0.05). In group H, rumen and fecal microbiota synergism was disrupted. In the H group, the host metabolome exhibited enrichment in pyruvate metabolism and the tricarboxylic acid cycle (p < 0.05). Key factors bridging the relationship between gastrointestinal microbiota and serum metabolites included the rumen bacterial genus g__Ruminococcus, serum HSP-70, malic acid, and fumaric acid. These hubs served as potential indicators for distinguishing the response to heat stress in calves (p < 0.05). In conclusion, this study identified the relationship between gastrointestinal microbiota characteristics and different HS responses of the host, thus providing evidence and new directions for future studies aimed at understanding HS in individual calves (gut microbiota-host interactions). Full article

Extraintestinal pathogenic Escherichia coli (ExPEC) is a group of Escherichia coli strains that can cause severe infectious diseases outside the gastrointestinal tract, such as urinary tract infections, meningitis, septicemia, etc. We report a case of a calf herd infection by ExPEC with high rates of morbidity and mortality. The research purpose of this study was to thoroughly investigate the characteristics of the ExPEC responsible for the calf herd infection. Specifically, we aimed to understand the mechanisms underlying its multidrug resistance and high pathogenicity. Clinical samples were collected for the isolation and identification of ExPECs, cultured on MacConkey agar, and further tested by PCR for the uidA gene, 16S rRNA gene sequencing, and adhesion patterns on HEp-2 cells. The antimicrobial activity was determined using the disk diffusion method according to Clinical & Laboratory Standards Institute (CLSI) guidelines. The pathogenicity was assessed through the experimental infection of Kunming mice, tracking their survival and weight changes, and performing autopsies for bacterial counts and histopathological analysis. Additionally, whole-genome sequencing (WGS) and a comprehensive analysis were performed, including multilocus sequence typing (MLST), serotyping, drug-resistance gene analysis, virulence factor analysis, metabolic pathway analysis, and enrichment analysis, using various online tools and databases. An ExPEC strain named RZ-13 was responsible for this case and was identified as ST345 and O134: H21. Among the 14 antibiotics tested, 13 showed resistance, indicating that the RZ-13 strain is a multidrug-resistant (MDR) bacterium. The experimental infection of Kunming mice proved the greater pathogenicity of RZ-13 than that of CICC 24186. The comprehensive WGS revealed the presence of 28 antibiotic resistance genes and 86 virulence-related genes in the genome of the strain, corroborating its clinical manifestations of MDR and high pathogenicity. Our study isolated a MDR ExPEC strain, RZ-13, with a strong pathogenicity. This is the first case report of ExPEC leading to severe mortality in calf herds in China, underscoring the need for the rational use of antibiotics to reduce the risk of the generation and transmission of MDR bacteria from food-producing animals to ensure food safety and public health. Full article

In the diet of calves, the search for additives that aid in their development is essential due to the impact that these can generate throughout their lives, resulting in a relationship with their longevity and the maintenance of the herd. Yuca schidigera has been used in ruminant diets, impacting health and performance; however, there are few reports on its intake by dairy cattle in the rearing phase. Therefore, this study’s objective was to evaluate whether adding Yucca schidigera to the diet of calves in the rearing phase can benefit health, productive performance, and feed efficiency. The study was conducted over 60 days, with 24 calves divided into two groups: G1 had no added Yucca schidigera and G2 had 188 mg of Yucca schidigera added per kg of dry matter intake. Data and samples were collected at 30-day intervals. No treatment effect was observed in body weight, weight gain, daily weight gain, or feed intake (p > 0.05); however, the calves in G2 showed 26.3% lower feed efficiency than those in G1. Using the concentrate consumption of the calves, the amount of Yucca schidigera ingested was calculated, i.e., 555 mg/calf/day. The total leukocyte count was significantly lower in the calves in G2 compared to G1 on the 60th day. No effect from the treatment or treatment × day interaction was observed for the hematologic variables: erythrocytes, hemoglobin, hematocrit, lymphocytes, granulocytes, monocytes, and platelets. The activities of the enzyme’s gamma glutamyl transferase and aspartate aminotransferase were higher in the animals in group G2. There was no effect from the treatment on albumin, globulin, total protein, C-reactive protein, glucose, cholesterol, urea, or amylase. There was a treatment × day interaction for levels of reactive oxygen species, lipid peroxidation, and glutathione S-transferase, which were higher in the blood of calves in group G2 compared to the control. The activity of myeloperoxidase, superoxide dismutase, and catalase did not differ between groups. Tumor necrosis factor and interleukins (IL-1 and IL-6) in the serum of calves that consumed Yucca schidigera were higher on day 60 compared to the control. A higher concentration of short-chain fatty acids in the ruminal fluid was observed in animals in group G2 compared to G1, primarily due to the higher levels of acetic acid. The amounts of propionate and butyrate were lower in the ruminal fluid of calves in group G2. These results allow us to conclude that the consumption of Yucca schidigera at a dose of 555 mg/animal/day interferes with calves’ metabolism and negatively affects feed efficiency. Full article