Antibiogram of Escherichia coli Isolated from Dairy Cattle and in-Contact Humans in Selected Areas of Central Ethiopia.

Background: Antimicrobial resistance (AMR) is a global threat to public and animal health. Escherichia coli is considered an indicator organism for monitoring AMR among gram-negative Enterobacteriaceae in humans and animals. The current study aims to assess the antibiogram profile of E. coli isolated from dairy cattle and in-contact humans in central Ethiopia and to identify risk factors associated with multidrug resistance (MDR). Methods: A cross-sectional study was conducted in which 58 farms were recruited from selected districts of central Ethiopia. E. coli was isolated using standard bacteriological techniques. A total of 200 representative isolates (140 from cattle and 60 from humans in contact) were randomly selected and tested for susceptibility to a panel of 13 antimicrobials using the Kirby-Bauer disc diffusion assay. Results: The highest rate of resistance was observed for sulfamethoxazole+trimethoprim (58.6%, 82/140) and amoxicillin+clavulanic acid (70.0%, 42/60) among E. coli isolates from cattle and hmans, respectively. In contrast, resistance rates in isolates from in contact humans with the cattle were 30%, 33.3%, and 66.7%, respectively. Resistance to tetracycline (p=0.02), streptomycin (p=0.03), and sulfamethoxazole+trimethoprim (p=0.007) was significantly high in E. coli isolated from cattle on commercial dairy farms than in those isolated from cattle on smallholder farms. There was no significant difference (p>0.05) in the rate of resistance between E. coli isolated from in contact humans with smallholder and commercial dairy farms. Antimicrobial use for treatment purpose (p=0.04) and non-compliance with the drug withdrawal period (p=0.03) were significantly associated with the farm-level occurrence of MDR. Conclusion: A high rate of resistance was detected in E. coli isolated from the feces of dairy cattle and in-contact humans. This necessitates an effective intervention through a one-health approach and further molecular studies are required to establish source attribution.

Multiplex fluorescent amplification-refractory mutation system PCR method for the detection of 10 genetic defects in Holstein cattle and its comparison with the KASP genotyping assay.

The common deleterious genetic defects in Holstein cattle include haplotypes 1-6 (HH1-HH6), haplotypes for cholesterol deficiency (HCD), bovine leukocyte adhesion deficiency (BLAD), complex vertebral malformation (CVM) and brachyspina syndrome (BS). Recessive inheritance patterns of these genetic defects permit the carriers to function normally, but homozygous recessive genotypes cause embryo loss or neonatal death. Therefore, rapid detection of the carriers is essential to manage these genetic defects. This study was conducted to develop a single-tube multiplex fluorescent amplification-refractory mutation system (mf-ARMS) PCR method for efficient genotyping of these 10 genetic defects and to compare its efficiency with the kompetitive allele specific PCR (KASP) genotyping assay. The mf-ARMS PCR method introduced 10 sets of tri-primers optimized with additional mismatches in the 3' end of wild and mutant-specific primers, size differentiation between wild and mutant-specific primers, fluorescent labeling of universal primers, adjustment of annealing temperatures and optimization of primer concentrations. The genotyping of 484 Holstein cows resulted in 16.12% carriers with at least one genetic defect, while no homozygous recessive genotype was detected. This study found carrier frequencies ranging from 0.0% (HH6) to 3.72% (HH3) for individual defects. The mf-ARMS PCR method demonstrated improved detection, time and cost efficiency compared with the KASP method for these defects. Therefore, the application of mf-ARMS PCR for genotyping Holstein cattle is anticipated to decrease the frequency of lethal alleles and limit the transmission of these genetic defects.

Administering the maternal appeasing substance before slaughter to improve carcass characteristics of finishing cattle.

Two experiments evaluated carcass characteristics of finishing steers administered the maternal bovine appeasing substance (mBAS) prior to slaughter. In Exp. 1, 954 Angus-influenced finishing steers housed in 6 original pens were used. Each original pen was split into a pair of experimental pens 14.3 d ±â€…3 d prior to slaughter, in a manner that number of steers and average pen body weight (BW; 636 ±â€…4 kg) were similar. An oiler containing mBAS (Ferappease Finish Cattle 5%; FERA Diagnostics and Biologicals; College Station, TX) was added to one of the experimental pens 7 d prior to slaughter (n = 6), whereas the other pen did not contain an oiler (CON; n = 6). The oiler delivered 120 mL of mBAS/steer during a 7-d period. Steer BW was recorded 7 d prior to and during loading (final BW) to the packing plant. No treatment effects were detected (P ≥ 0.51) for BW gain, final BW, and proportion of carcasses that graded Choice or Prime. Carcass dressing percentage was greater (P = 0.02) in mBAS compared with CON steers (65.9% vs. 64.2%; SEM = 0.5), which was not sufficient to impact hot carcass weight (HCW; P = 0.29). Incidence of dark-cutting carcasses did not differ between treatments (P = 0.23). In Exp. 2, 80 Angus-influenced finishing steers housed in 16 pens (5 steers/pen; 600 ±â€…4 kg of BW) were used. Pens were arranged in 4 rows of 4 pens/row, and rows were alternately assigned to receive an oiler containing mBAS (n = 8) or mineral oil (CON+; n = 8) 7 d prior to slaughter. Oilers were designed to deliver 120 mL/steer of mBAS or mineral oil during the 7-d period. Steer BW was recorded as in Exp. 1, and a blood sample was collected during exsanguination. No treatment effects were detected (P ≥ 0.20) for BW parameters, carcass marbling score, backfat thickness, Longissimus muscle area, yield grade, and proportion of carcasses that graded Choice or Prime. Carcass dressing was greater (P = 0.02) in mBAS steers compared with CON + (60.6 vs. 59.6%; SEM = 0.3) but HCW did not differ (P = 0.47) between treatments. Plasma cortisol concentration was less (P < 0.01) in mBAS steers compared with CON + (11.7 vs. 20.8 ng/mL; SEM = 1.6). Incidence of dark-cutting carcasses did not differ (P = 0.53) between treatments. In summary, mBAS administration to finishing cattle using oilers during the last 7 d on feed alleviated the adrenocortical stress response elicited by the process of slaughter, which likely resulted in increased carcass dressing.

Empirical analysis of drought-induced cattle destocking in South Africa.

Destocking as a drought mitigation strategy exposes smallholder cattle farmers to adverse effects, including the distortion of farm planning and income loss, as cattle are sold off regardless of the market price. Factors influencing destocking as a drought mitigation strategy for smallholder cattle farmers have received less attention in the literature. The study assessed the relationship between drought and cattle destocking as well as factors that affect farmers' destocking decision. The relationship between drought and cattle destocking was assessed using correlation analysis, while determinants of destocking were identified through the zero-inflated Poisson (ZIP) regression model, which controlled for structural zeros. The research covered the period 2008-2017 using secondary data from the National Income Dynamics Study (NIDS), the South Africa Weather Service and the Food and Agriculture Organisation (FAO). The study found that drought has direct correlation with the quantity of beef produced in South Africa at -0.67, with a 1% significance level. Farmers' socioeconomic characteristics such as cattle herd size, income, secondary occupation, fodder purchase and ownership of land positively influenced cattle destocking decision while household size and cattle loss during drought influenced destocking decision negatively. Contribution: The study estimated the determinants of smallholder cattle farmers' decision to destock during drought, using a count model and accounted for socioeconomic and farmer-specific factors.

Effects of dietary energy levels on microorganisms and short-chain fatty acids of rumen and tight junction proteins in Honghe Yellow cattle.

This study was conducted to investigate the effects of dietary energy levels on microorganisms and short-chain fatty acids (SCFAs) of rumen and the expression of tight junction proteins in Honghe Yellow cattle. A total of fifteen male Honghe Yellow cattle were randomly divided into three treatments (five replicates per treatment), consisting of formulated energy concentrations of 5.90 MJ/kg (high-energy diet, group H), 5.60 MJ/kg (medium-energy diet, group M) and 5.30 MJ/kg (low-energy diet, group L). The results showed that compared with group H, the expression of Claudin-1 in rumen epithelium of groups M and L was increased, but the expression of ZO-1 was decreased (p < 0.05). Moreover, compared with group H, group M down-regulated the expression of Occludin and Claudin-1 in the brain (p < 0.05). For rumen bacteria, the dominant phyla included Bacteroidetes and Firmicutes, the abundance of Actinobacteriota in groups M and L was significantly increased compared with group H (p < 0.05). At the genus level, the relative abundance of Corynebacterium, Eubacterium_nodatum_group and Neisseraceae in groups M and L was significantly decreased compared with group H (p < 0.05). For rumen fungi, the dominant phyla included Basidiomycota, Ascomycota and Neocariastigomycota, the relative abundance of Ascomycetes was significantly higher than that of groups M and L compared with group H (p < 0.05). At the genus level, the relative abundance of Neocelimastigaceae and Myceliophthora in groups M and L was significantly reduced compared with group H (p < 0.05). Furthermore, the expression of Claudin-1 in rumen epithelium was significantly positively correlated with Actinobacteriota, Corynebacterium and Neisseriaceae. The expression of ZO-1 in the spinal cord was significantly positively correlated with Myceliophthora. The expression of Occludin in brain was positively correlated with valerate content (p < 0.05). In summary, dietary energy levels affected the rumen microbiota of Honghe Yellow cattle. The expression of Claudin-1 in rumen epithelium and the total SCFAs concentration were increased with decreasing dietary energy levels, but the expression of Claudin-1 in brain and ZO-1 in the spinal cord were reduced with decreasing dietary energy levels. Meanwhile, the rumen microbiota and SCFAs were significantly correlated with the expression of TJP.

The effects of a glyphosate-based herbicide on the bovine gametes during an in vitro embryo production model.

Roundup® (R), while it is the most used herbicide globally, and its residues are ubiquitous in urban and suburban areas, its impact on vertebrates' safety remains highly debated. Here, in three in vitro experiments, we investigated the effects of a very low dose (1 ppm) of R on the fertilization capacity and embryo development in cattle. In the first experiment, frozen-thawed bull semen exposed to R for 1 h exhibited reduced motility parameters but unaffected fertilization ability. However, after in vitro fertilization, the rates of embryo formation were significantly lower compared to the untreated controls. In the second experiment, oocytes exposed to R during in vitro maturation showed reduced cleavage rates, and the embryo yield on days 7, 8, and 9 of embryo culture was significantly lower than that of the controls. In the third experiment, oocytes were matured in the presence of R and in a medium containing both R and Zinc, chosen to offer antioxidant protection to the oocytes. Day-7 blastocysts were analyzed for the expression of genes associated with oxidative stress, apoptosis, and epigenetic reprogramming. Exposure to R markedly suppressed embryo formation rates compared to the controls. The combination of R with Zinc restored the blastocyst yield, which on days 8 and 9 was comparable to that of the controls and higher than the groups exposed only to R on all days. The gene expression analysis revealed that R promotes oxidative stress development, triggers apoptosis, and induces epigenetic changes in developing embryos, while zinc presence alleviates these adverse effects of R. These findings imply that even at very low doses, R could be highly toxic, leading to functional abnormalities in both gametes, potentially affecting fertility in both genders.

Physiological high temperatures alter the amino acid metabolism of bovine early antral follicles.

Heat stress reduces the developmental competence of bovine oocytes during the growth phase; however, the detailed mechanisms remain unclear. Amino acids play various critical roles in follicular development, including protein synthesis and as energy sources. We performed in vitro growth (IVG) culture of oocyte-cumulus-granulosa complexes (OCGCs) to assess the amino acid metabolism of small follicles at high temperatures. We isolated OCGCs from early antral follicles (0.5-1.0 mm) and subjected them to IVG culture for 12 days. OCGCs in the heat shock group were cultured under a temperature cycle of (38.5°C: 5 h, 39.5°C: 5 h, 40.5°C: 5 h, and 39.5°C: 9 h) to reproduce the body temperature of lactating cows under a hot environment. OCGCs in the control group were cultured at a constant temperature of 38.5°C for 24 h. Of the surviving OCGCs, those showing similar morphology and size between the groups were selected for amino acid analysis. We analyzed the free amino acids and their metabolites in the culture medium and calculated the depletion or appearance of molecular species. The depletion of three essential amino acids (isoleucine, leucine, and valine), two non-essential amino acids (aspartic acid and glycine), and ornithine was higher in the heat shock group (P < 0.05). Alanine depletion was lower in the heat shock group (P < 0.05). We concluded that heat exposure alters the amino acid metabolism of OCGCs isolated from early antral follicles, which might be involved with the diminished developmental potential of oocytes during summer.

Effect of Intra-ovarian Injection of Mesenchymal Stem Cells or its Conditioned Media on Repeated OPU-IVEP Outcomes in Jersey Heifers and Its Relationship with Follicular Fluid Inflammatory Markers.

Background: Repeated Ovum Pick Up (OPU) could have a detrimental effect on ovarian function, reducing In Vitro Embryo Production (IVEP). The present study examined the therapeutic effect of adipose-derived Mesenchymal Stem Cells (MSCs) or its Conditioned Medium (ConM) on ovarian trauma following repeated OPU. Resolvin E1 (RvE1) and Interleukin-12 (IL-12) were investigated as biomarkers. Methods: Jersey heifers (n=8) experienced 11 OPU sessions including 5 pre-treatment and 6 treatment sessions. Heifers received intra-ovarian administration of MSCs or ConM (right ovary) and Dulbecco's Modified Phosphate Buffer Saline (DMPBS; left ovary) after OPU in sessions 5 and 8 and 2 weeks after session 11. The concentrations of RvE1 and IL-12 in follicular fluid was evaluated on sessions 1, 5, 6, 9, and 4 weeks after session 11. Following each OPU session, the IVEP parameters were recorded. Results: Intra-ovarian administration of MSCs, ConM, and DMPBS did not affect IVEP parameters (p>0.05). The concentration of IL-12 in follicular fluid increased at the last session of pre-treatment (Session 5; p<0.05) and remained elevated throughout the treatment period. There was no correlation between IL-12 and IVEP parameters (p>0.05). However, RvE1 remained relatively high during the pre-treatment and decreased toward the end of treatment period (p<0.05). This in turn was associated with decline in some IVEP parameters (p<0.05). Conclusion: Intra-ovarian administration of MSCs or ConM during repeated OPU did not enhance IVEP outcomes in Bos taurus heifers. The positive association between RvE1 and some of IVEP parameters could nominate RvE1 as a promising biomarker to predict IVEP parameters following repeated OPU.

Genomic Analysis of Inbreeding and Coancestry in Nordic Jersey and Holstein Dairy Cattle Populations.

In recent years, Genomic Selection (GS) has accelerated genetic gain in dairy cattle breeds worldwide. Despite the evident genetic progress, several dairy populations have also encountered challenges such as heightened inbreeding rates and reduced effective population sizes. The challenge has been to find a balance between achieving substantial genetic gain while managing genetic diversity within the population, thereby mitigating the negative effects of inbreeding depression. This study aims to elucidate the impact of GS on pedigree and genomic rates of inbreeding (ΔF) and coancestry (ΔC) in Nordic Jersey (NJ) and Holstein (NH) cattle populations. Furthermore, key genetic metrics including the generation interval (L), effective population size (Ne), and future effective population size (FNe) were assessed between 2 time periods, before and after GS, and across distinct animal cohorts in both breeds: females, bulls, and approved semen-producing bulls (AI-sires). Analysis of ΔF and ΔC revealed distinct trends across the studied periods and animal groups. Notably, there was a consistent increase in yearly ΔF for most animal groups in both breeds. An exception was observed in NH AI-sires, which demonstrated a slight decrease in yearly ΔF. Moreover, NJ displayed minimal changes in yearly ΔC between the periods, whereas NH exhibited elevated ΔC values across all animal groups. Particularly striking was the substantial increase in yearly ΔC within the NH female population, surging from 0.02% to 0.39% between the periods. Implementation of GS resulted in a reduction of the generation interval across all animal cohorts in both NJ and NH breeds. However, the extent of reduction was more pronounced in males compared with females. This reduction in generation interval influenced generational changes in ΔF and ΔC. Bulls and AI-sires of both breeds exhibited reduced generational ΔF between periods, in contrast to females that demonstrated an opposing pattern. Between the periods, NJ maintained a relatively stable Ne, 29.4 before and 30.3 after GS, while NH experienced a notable decline from 54.3 to 42.8. Female groups in both breeds displayed a negative Ne trend, while males demonstrated either neutral or positive Ne developments. Regarding FNe, NJ exhibited positive FNe development with an increase from 40.7 to 57.2. The opposite was observed in NH, where FNe decreased from 198.8 to 42.7. In summary, it was evident that the genomic methods could detect differences between the populations and changes in ΔF and ΔC more efficiently than pedigree methods. GS implementation yielded positive outcomes within the NJ population regarding the rate of coancestry but the opposite was observed with NH. Moreover, analysis of ΔC data hints at the potential to decrease future ΔF through informed mating strategies. Conversely, NH faces more pressing concerns, even though ΔF remains comparatively modest in contrast to what has been observed in other Holstein populations. These findings underscore the necessity of genomic control of inbreeding and coancestry with strategic changes in the Nordic breeding schemes for dairy to ensure long-term sustainability in the forthcoming years.

Prognostic indicators of outcome in nonambulatory beef cattle presented to 2 referral hospitals: A retrospective study of 63 cases.

BACKGROUND: Down cow syndrome is commonly described in dairy cattle. The diagnosis and treatment of nonambulatory cattle is challenging and prognostic indicators of this condition in beef cattle have not been determined. OBJECTIVES: Evaluate records of beef cattle (≥2 years of age) presented to 2 referral hospitals for inability to stand and identify prognostic indicators for survival to discharge. ANIMALS: Sixty-three adult beef cattle treated for inability to stand at 2 referral hospitals. METHODS: Medical records of 63 beef cattle presented for inability to stand between January 2010 and December 2022 were retrospectively analyzed. Continuous and categorical variables were included in univariate and multivariate regression models to evaluate their association with outcome. RESULTS: Of 63 animals included in the study, 19% (12/63) were discharged, and the remaining 81% (n = 51) either died (11.1%) or were euthanized (69.8%). The odds of being discharged increased with each additional day of hospitalization (odds ratio [OR], 2.66; 95% confidence interval [CI], 1.39-6.89) and with each additional flotation therapy session (OR, 2.108; 95% CI, 1.209-4.219). Down beef cattle with a diagnosis of calving peripheral nerve paralysis and capable of walking out the tank after the first flotation session were 6.66 (95% CI, 1.58-35.51) and 30 (95% CI, 4.4-614.98) times more likely to be discharged compared with cattle that had other diagnoses and those that were unable to walk out the tank, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment of nonambulatory beef cattle carries a poor prognosis. Practitioners can use information from our study as a guide for treatment or euthanasia decisions of nonambulatory beef cattle.

Trace mineral source and chromium propionate supplementation affect performance and carcass characteristics in feedlot steers.

Angus-crossbred steers (n = 400; 369.7 ± 7.6 kg) were used to determine the influence of trace mineral (TM) source and chromium propionate (Cr Prop) supplementation on performance, carcass characteristics, and ruminal and plasma variables in finishing steers. Steers were blocked by body weight (BW) and randomly assigned within block to treatments in a 2 x 2 factorial arrangement, with factors being: 1) TM source (STM or HTM) and 2) Cr supplementation (0 or 0.25 mg Cr/kg DM, -Cr or +Cr, respectively). Treatments consisted of the addition of: 1) sulfate TM (STM; 90, 40, and 18 mg/kg DM of Zn, Mn, and Cu, respectively), 2) STM and 0.25 mg Cr/kg DM from Cr Prop, 3) hydroxychloride TM (HTM; 90, 40, and 18 mg/kg DM of Zn, Mn, and Cu, respectively), and 4) HTM and 0.25 mg Cr/kg DM from Cr Prop. Each treatment consisted of 10 replicate pens with 10 steers per pen. Body weights were obtained on consecutive days at the initiation and termination of the 154-d study. Steers were fed a steam-flaked corn-based finishing diet. Ractopamine hydrochloride was fed for the last 31 d of the study. Ruminal fluid and blood samples were obtained from one steer per pen on d 28 and 84 for ruminal volatile fatty acids (VFA) and plasma TM and glucose analysis. Steers were slaughtered at the end of the study and individual carcass data were collected. No Cr x TM source interactions were detected. Steers supplemented with HTM had greater (P ˂ 0.04) hot carcass weight (HCW), dressing percentage (DP), longissimus muscle (LM) area, and USDA yield grade (YG), and tended (P ˂ 0.12) to have greater average daily gain (ADG) than those receiving STM. Average daily gain, gain:feed, dressing percentage, and longissimus muscle area were greater (P ˂ 0.04) for +Cr steers compared to - Cr steers. Hot carcass weight tended (P ˂ 0.06) to be greater for +Cr steers. Ruminal acetate concentrations at 28 d were lesser (P ˂ 0.01) for HTM vs. STM steers, and greater (P ˂ 0.04) for +Cr steers compared to - Cr steers. Plasma concentrations of Zn, Cu, and Mn were not affected by TM source or Cr supplementation. Steers supplemented with Cr had greater (P ˂ 0.05) plasma glucose concentrations than - Cr steers at 28 but not at 84 d. Results of this study indicate replacing STM with HTM improved carcass characteristics in finishing steers, and Cr Prop supplementation improved steer performance and carcass characteristics.

Effect of composting and storage on the microbiome and resistome of cattle manure from a commercial dairy farm in Poland.

Manure from food-producing animals, rich in antibiotic-resistant bacteria and antibiotic resistance genes (ARGs), poses significant environmental and healthcare risks. Despite global efforts, most manure is not adequately processed before use on fields, escalating the spread of antimicrobial resistance. This study examined how different cattle manure treatments, including composting and storage, affect its microbiome and resistome. The changes occurring in the microbiome and resistome of the treated manure samples were compared with those of raw samples by high-throughput qPCR for ARGs tracking and sequencing of the V3-V4 variable region of the 16S rRNA gene to indicate bacterial community composition. We identified 203 ARGs and mobile genetic elements (MGEs) in raw manure. Post-treatment reduced these to 76 in composted and 51 in stored samples. Notably, beta-lactam, cross-resistance to macrolides, lincosamides and streptogramin B (MLSB), and vancomycin resistance genes decreased, while genes linked to MGEs, integrons, and sulfonamide resistance increased after composting. Overall, total resistance gene abundance significantly dropped with both treatments. During composting, the relative abundance of genes was lower midway than at the end. Moreover, higher biodiversity was observed in samples after composting than storage. Our current research shows that both composting and storage effectively reduce ARGs in cattle manure. However, it is challenging to determine which method is superior, as different groups of resistance genes react differently to each treatment, even though a notable overall reduction in ARGs is observed.

Validation of a commercial ELISA kit to measure 11-oxoetiocholanolone in equine and bovine feces.

Feces are a noninvasive and easily collectible matrix that may help determine cumulative hormone metabolite concentrations over medium-to-long times. To date, 11-oxoetiocholanolone, an important metabolite of cortisol, has been measured in equine and bovine feces solely by an in-house enzyme immunoassay (EIA). Therefore, we validated the use of a commercial ELISA kit (11-oxoetiocholanolone ELISA kit; Cayman Chemical), which had been validated on sheep feces and human urine, to measure 11-oxoetiocholanolone in feces from 42 horses and 32 bulls. The ELISA kit had good precision (intra- and inter-assay CVs: 5.8% and 11.2% for equine feces; 9.9% and 11.2% for bovine feces, respectively), analytical sensitivity (0.186 ng/mL for both equine and bovine feces), and accuracy (parallelism and recovery tests) in determining 11-oxoetiocholanolone concentrations in feces from both species. We found ranges of 11-oxoetiocholanolone concentrations of 1-109 ng/g in equine feces and 40-302 ng/g in feces of bulls. The Cayman Chemical ELISA kit offers a simple and accessible means of analysis of 11-oxoetiocholanolone in equine and bovine fecal samples.

Isolation and propagation of an Egyptian Theileria annulata infected cell line and evaluation of its use as a vaccine to protect cattle against field challenge.

Tropical theileriosis is an important protozoan tick-borne disease in cattle. Vaccination using attenuated schizont-infected cell lines is one of the methods used for controlling the disease. This study describes the production of attenuated schizont-infected cell lines from Egypt and an evaluation of its use as a vaccine to protect calves against clinical disease upon field challenge. Two groups of exotic and crossbred male calves were divided into vaccinated and control groups. The vaccinated groups were inoculated with 4 ml (1 × 106 cells/ml) of the attenuated cell line. Three weeks after vaccination, calves of both groups were transported to the New Valley Governorate (Egyptian oasis) where they were kept under field conditions and exposed to the natural Theileria annulata challenge. All animals in the control group showed severe clinical signs and died despite treatment with buparvaquone, which was administered after two days of persistent fever due to a severe drop in packed cell volume (PCV). Animals in the vaccinated group became seropositive without developing severe clinical signs other than transient fever. Post-mortem examinations revealed enlarged and fragile lymph nodes, spleen, and liver with necrosis and hemorrhages. These findings indicate that the Egyptian attenuated cell line was successful in protecting both exotic and crossbred animals against tropical theileriosis under field conditions.

Hydrolysis of Beef Sarcoplasmic Protein by Dry-Aged Beef-Isolated Penicillium oxalicum and Its Associated Metabolic Pathways.

Yanbian cattle have a unique meat flavor, and high-grade meat is in short supply. Therefore, in this study, we aimed to improve the added value of Yanbian cattle low-fat meat and provide a theoretical reference for the subsequent development of an excellent starter. Rump meat from Yanbian cattle was dry-aged and then screened for protease-producing fungi. Three protease-producing fungi (Yarrowia hollandica (D4 and D11), Penicillium oxalicum (D5), and Meesziomyces ophidis (D20)) were isolated from 40 d dry-aged beef samples, and their ability to hydrolyze proteins was determined using bovine sarcoplasmic protein extract. SDS-PAGE showed that the ability of Penicillium oxalicum (D5) to degrade proteins was stronger than the other two fungi. In addition, the volatile component content of sarcoplasmic proteins in the D5 group was the highest (45.47%) and comprised the most species (26 types). Metabolic pathway analysis of the fermentation broth showed that phenylalanine, tyrosine, and tryptophan biosynthesis was the most closely related metabolic pathway in sarcoplasmic protein fermentation by Penicillium oxalicum (D5). Dry-aged beef-isolated Penicillium oxalicum serves as a potential starter culture for the fermentation of meat products.

Pine needle abortions in cattle due to consumption of Pinus ponderosa in Argentina: Case reports.

Two outbreaks of pine needle abortions in cattle are here reported for the first time in Argentina. The cases occurred in Chubut and Neuquén provinces in the Patagonia region, causing 29.6% and 9% of abortions in each herd respectively. In both outbreaks, the dams were in the last third of gestation, and, due to a period of cold, snow and lack of available forage, they gained access to Pinus ponderosa and Pinus contorta forests. No pathological lesions, serological, molecular, or microbiological evidence of infectious causes were observed in any of the six fetuses analyzed. Microhistological analysis of feces confirmed higher presence of fragments of Pinus spp. needles in the diet of affected dams than in that of non-affected ones (12.2 vs 3.0%). Moreover, toxicological analysis showed higher tetrahydroagathic acid in the sera of affected dams than in that of non-affected ones (10.05 vs 2.81 ppm). In addition, this acid was detected in different fetal fluids (3.6-8.1 ppm) of the six fetuses analyzed. Interestingly, isocupressic acid was detected only in needles of P. ponderosa, and its content was lower than that found in other areas of the world (0.31 and 0.5% in Chubut and Neuquén respectively). These results confirm that the consumption of P. ponderosa by dams could have been the cause of these abortion outbreaks, a fact that should be considered as differential diagnosis in abortions of cattle, especially in silvopastoral systems of Argentina.

Genomic insights into the population history and adaptive traits of Latin American Criollo cattle.

Criollo cattle, the descendants of animals brought by Iberian colonists to the Americas, have been the subject of natural and human-mediated selection in novel tropical agroecological zones for centuries. Consequently, these breeds have evolved distinct characteristics such as resistance to diseases and exceptional heat tolerance. In addition to European taurine (Bos taurus) ancestry, it has been proposed that gene flow from African taurine and Asian indicine (Bos indicus) cattle has shaped the ancestry of Criollo cattle. In this study, we analysed Criollo breeds from Colombia and Venezuela using whole-genome sequencing (WGS) and single-nucleotide polymorphism (SNP) array data to examine population structure and admixture at high resolution. Analysis of genetic structure and ancestry components provided evidence for African taurine and Asian indicine admixture in Criollo cattle. In addition, using WGS data, we detected selection signatures associated with a myriad of adaptive traits, revealing genes linked to thermotolerance, reproduction, fertility, immunity and distinct coat and skin coloration traits. This study underscores the remarkable adaptability of Criollo cattle and highlights the genetic richness and potential of these breeds in the face of climate change, habitat flux and disease challenges. Further research is warranted to leverage these findings for more effective and sustainable cattle breeding programmes.

The Meat Standards Australia carcass grading site affects assessment of marbling and prediction of meat-eating quality in growing European beef cattle.

The lack of consumer feedback on beef eating quality contributes to reduced beef consumption in Europe. The Meat Standards Australia (MSA) grading scheme can assess the palatability of beef carcasses usually graded at the 10th thoracic vertebrae. However, the European beef industry relies on late-maturing breeds usually cut at the 5th vertebrae due to commercial reasons. Data from 55 young bulls and heifers of late-maturing breeds were collected in an Italian slaughterhouse following the MSA guidelines at both carcass grading sites and sides. Intramuscular fat levels were assessed through two scores and used with other variables to feed the MSA model, which predicts the MSA index, the meat-eating quality scores (MQ4) for 5 muscles and for each carcass grading site × side combination. The scores were analyzed using a mixed linear model. A correlation analysis was conducted to predict the variables measured at the 10th site using their correspondent at the 5th carcass grading site. A stepwise regression was conducted to understand the weight of each measured variable on marbling and MQ4 scores measured both at 5th and 10th carcass grading sites. Results showed significantly higher value for the studied traits at the 5th carcass grading site, while carcass side had no significant impact. The equations had high predictive capability and MSA marbling score played a key role in explaining the variability across carcass grading sites. The differences in marbling and MQ4 scores between the carcass grading sites suggest considering this factor if the MSA grading system will be applied to Europe.

Risk factors affecting the feeding site predilection of ticks on cattle in Ghana.

Ticks are important disease vectors affecting animal health and causing substantial economic loss, especially in the tropics and subtropics. To examine the tick burden of cattle and associated risk factors for tick infestation, ticks were collected from 388 cattle within five regions in Ghana. Most of the cattle were males (50.3%) and generally older than 3 years (65%). Of the animals sampled, 2187 ticks were collected with a mean tick burden of 5.6 ticks per cattle, and the average tick burden on the udder/scrotum being significantly higher than in the anal region (Generalized Linear Mix Model [GLMM], p = 0.01197). The tick species identified were predominantly Amblyomma variegatum (42.6%) and Hyalomma rufipes (26.2%). High proportions of cattle examined were found to have A. variegatum infesting the udder/scrotum. Furthermore, H. rufipes infested mostly the anal region compared to other examined body parts (OR 14.8, 95% CI 8.6-25.4, p < 0.001). Using the GLMM, tick abundance was found to be significantly higher in cattle older than 3 years. The tick burden in the udder/scrotum was higher than that from the chest and leg/thigh of the cattle (GLMM, p < 0.05). The tick burden at the anal region was also significantly higher than the leg/thigh and chest. This study indicates that the preferred attachment sites of ticks on cattle are species-dependent and effective treatment with acaricides should take into consideration the udder/scrotum and anal regions as well as prioritizing older cattle.

In vitro effects of two environmental toxicants, beauvericin and glyphosate in Roundup, on cell numbers and steroidogenesis of bovine ovarian cells.

Beauvericin is an emerging Fusariotoxin naturally occurring in cereal grains throughout the world whereas glyphosate (N-phosphonomethyl-glycine) is a non-selective systemic herbicide used worldwide. The purpose of this study is to evaluate a newly developed ovarian cell culture system (that includes both granulosa and theca cells) as an in vitro model for toxicological studies. Specifically, the effects of beauvericin and glyphosate in formulation with Roundup on ovarian cell numbers and steroid production were evaluated. Ovaries collected from cattle without luteal structures were sliced into 30-70 pieces each, and granulosa and theca cells were collected. Harvested cells were cultured for 48 h in 10% fetal bovine serum-containing medium followed by 48 h in serum-free medium containing testosterone (500 ng/mL; as an estrogen precursor) with the following eight treatments: (1) controls, (2) FSH (30 ng/mL) alone, (3) FSH plus insulin-like growth factor-1 (IGF1; 30 ng/mL), (4) FSH plus IGF1 plus beauvericin (3 µM), (5) FSH plus IGF1 plus glyphosate in Roundup (10 µg/mL), (6) FSH plus IGF1 plus fibroblast growth factor 9 (FGF9, 30 ng/mL), (7) a negative control without added testosterone, and (8) IGF1 plus LH (30 ng/mL) with basal medium without added testosterone. In the presence of FSH, IGF1 significantly increased cell numbers, estradiol and progesterone production by severalfold. Glyphosate in Roundup formulation significantly inhibited IGF1-induced cell numbers and estradiol and progesterone production by 89-94%. Beauvericin inhibited IGF1-induced cell numbers and estradiol and progesterone by 50-97% production. LH plus IGF1 significantly increased androstenedione secretion compared with controls without added testosterone indicating the presence of theca cells. In conclusion, the present study demonstrates that toxicological effects of beauvericin and glyphosate in Roundup formulation are observed in a newly developed ovarian cell model system and further confirms that both glyphosate and beauvericin may have the potential to impair reproductive function in cattle.