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Social interactions between cows play a fundamental role in the daily activities of dairy cattle. Real-time location systems provide on a continuous and automated basis information about the position of individual cows inside barns, offering a valuable opportunity to monitor dyadic social contacts. Understanding dyadic social interactions could be applied to enhance the stability of the social structure promoting animal welfare and to model disease transmission in dairy cattle. This study aimed to identify the effect of different cow characteristics on the likelihood of the formation and persistence of social contacts in dairy cattle. The individual position of the lactating cows was automatically collected once per second for 2 wk, using an ultra-wideband system on a Swedish commercial farm consisting of almost 200 dairy cows inside a freestall barn. Social networks were constructed using the position data of 149 cows with available information on all characteristics during the study period. Social contacts were considered as a binary variable indicating whether a cow pair was within 2.5 m of each other for at least 10 min per day. The role of cow characteristics in social networks was studied by applying separable temporal exponential random graph models. Our results revealed that cows of the same parity interacted more consistently, as well as those born within 7 d of each other or closely related by pedigree. The repeatability of the topological parameters indicated a consistent short-term stability of the individual animal roles within the social network structure. Additional research is required to elucidate the underlying mechanisms governing the long-term evolution of social contacts among dairy cattle and to investigate the relationship between these networks and the transmission of diseases in the dairy cattle population. ., his project was funded by Formas, a Swedish Research Council for Sustainable Development, Stockholm, Sweden (ID: 2019–02276 and 2019–02111) and by the Kjell and Märta Beijer Foundation (Stockholm, Sweden).

Ketoconazole (KTZ) is widely used as a fungicide, but it is also known to target steroid hormone formation which may affect female reproductive health. Our study aims to investigate the effects of KTZ on in vitro matured bovine cumulus-oocyte complexes (COCs), as a model for female reproductive toxicity. Cumulus cells of in vitro maturing COCs produce progesterone and pregnenolone, but exposure to 10 -6M KTZ effectively blocked the synthesis of these hormones. Exposure to lower concentrations of KTZ (i.e. 10 -7M and 10 -8M) had no such effect on steroidogenesis compared to the 0.1% v/v DMSO vehicle control. Classical parameters of in vitro COC maturation, such as oocyte nuclear maturation to the metaphase II stage and expansion of the cumulus investment, were not affected by any KTZ concentration tested. Apoptosis and necrosis levels were also not altered in cumulus cells or oocytes exposed to KTZ. Moreover, oocytes exposed to KTZ during maturation showed normal cleavage and early embryo development up to day 8 post fertilization; albeit a statistically significant decrease was observed in day 8 blastocysts produced from oocytes exposed to the lowest concentration of 10 -8M KTZ. When unexposed mature oocytes were fertilized, followed by embryo culture for 8 days under KTZ exposure, no adverse effects in embryo cleavage and blastocyst formation were observed. In conclusion, KTZ has no major impact on in vitro bovine oocyte maturation and blastocyst formation in our study, even at concentrations blocking steroidogenesis.

The livestock industria is a crucial activista in the Ecuadorian economy, especially with regard to beef production. This study aimed to evaluate the phaneroptic characteristics of cattle, the relationship between body condition and carcass performance of crossbred cattle slaughtered in municipal slaughter centers in the central zone of Ecuador. Data were analyzed from 500 unregistered cattle (361 males and 139 females) collected during the months of October and November 2023 in the province of Tungurahua. Characteristics such as coat color, nose, hoof, dewlap, umbilical fold, udder and scrotum were evaluated, along with the body condition and live weight of the animals. The results showed a predominance of the mixed Holstein breed, followed by crosses between breeds. Significant correlations were found between live weight, body condition and carcass yield. Males tended to have a higher live weight compared to females, and higher live weight cattle presented superior performance. These findings provide a detailed understanding of the phenotypic characteristics and their relationship with carcass yield in crossbred cattle slaughtered in the central zone of Ecuador, which contributes to improving the efficiency and quality of livestock production in the region., La industria ganadera es una actividad crucial en la economía ecuatoriana, especialmente en lo que respecta a la producción de carne vacuna. Este estudio, tuvo como objetivo evaluar las características fanerópticas de los bovinos, la relación entre la condición corporal y rendimiento a la canal de los bovinos mestizos faenados en los centros de faenamiento municipales de la zona central del Ecuador. Se analizaron datos de se evaluaron 500 bovinos (361 machos y 139 hembras) sin registro recolectados durante los meses de octubre y noviembre de 2023 en la provincia de Tungurahua. Se evaluaron características como el color de capa, morro, pezuña, papada, pliegue umbilical, ubre y escroto, junto con la condición corporal y el peso vivo de los animales. Los resultados mostraron una predominancia de la raza Holstein mestiza, seguida de cruces entre razas. Se encontraron correlaciones significativas entre peso vivo, condición corporal y rendimiento a la canal. Los machos tendieron a tener un peso vivo mayor en comparación con las hembras, y los bovinos de mayor peso vivo presentaron un rendimiento superior. Estos hallazgos proporcionan una comprensión detallada de las características fenotípicas y su relación con el rendimiento a la canal en los bovinos mestizos faenados en la zona central de Ecuador, lo que contribuye a mejorar la eficiencia y calidad de la producción ganadera en la región.

Over the past decades, daughter designs, including genotyped sires and their genotyped daughters, have been used as an approach to identify QTL related to economic traits. The aim of this study was to identify genomic regions inherited by Gir sire families and genes associated with number of viable oocytes (VO), total number of oocytes (TO), and number of embryos (EMBR) based on a daughter design approach. In total, 15 Gir sire families were selected. The number of daughters per family ranged from 26 to 395, which were genotyped with different SNP panels and imputed to the Illumina BovineHD BeadChip (777K) and had phenotypes for oocyte and embryo production. Daughters had phenotypic data for VO, TO, and EMBR. The search for QTL was performed through GWAS based on GBLUP. The QTL were found for each trait among and within families based on the top 10 genomic windows with the greatest genetic variance. For EMBR, genomic windows identified among families were located on BTA4, BTA5, BTA6, BTA7, BTA8, BTA13, BTA16, and BTA17, and they were most frequent on BTA7 within families. For VO, genomic windows were located on BTA2, BTA4, BTA5, BTA7, BTA17, BTA21, BTA22, BTA23, and BTA27 among families, being most frequent on BTA8 within families. For TO, the top 10 genomic windows were identified on BTA2, BTA4, BTA5, BTA7, BTA17, BTA21, BTA22, BTA26, and BTA27, being most frequent on BTA7 and BTA8 within families. Considering all results, the greatest number of genomic windows was found on BTA7, where the VCAN, XRCC4, TRNAC-ACA, HAPLN1, and EDIL3 genes were identified in the common regions. In conclusion, 15 Gir sire families with 26 to 395 daughters per family with phenotypes for oocyte and embryo production helped to identify the inheritance of several genomic regions, especially on BTA7, where the EDIL3, HAPLN1, and VCAN candidate genes were associated with number of oocytes and embryos in Gir cattle families.

The reproductive efficiency and milk yield of cows are crucial factors in a dairy farm's profitability. However, abortions can have a negative impact on these factors. While the morbidity of abortion has been estimated in many countries, information on the burden on dairy cattle in tropical conditions is limited, and Costa Rica is a good example. This study aims to assess the incidence and recurrence of bovine abortion in dairy cattle from Costa Rica. The study analysed the morbidity of abortion in Costa Rican dairy herds between 2010 and 2022. The incidence rate (IR) and the recurrence rate (ReR) were calculated per 100 cow-months at risk using data from the Veterinary Automated Management and Production Control Programme (VAMPP). The dataset comprised 1032,457 lactations from 330,265 cows in 1134 specialized dairy herds. Abortions were classified either as early foetal mortality (EFM) or late foetal mortality (LFM). Rates were estimated based on cow breed, lactation number, and ecological zone to which the farm belongs. The IR of general abortion, EFM, and LFM cases were 0.98, 0.41, and 0.57 per 100 cow-months at risk, respectively. No statistically significant differences were found in the IR between cow breed, lactation number, and ecological zone, nor for the trend of abortions over calving years. The first ReR (for cows that had one previous abortion during the lactation) was 0.95, and the second ReR (for cows that had two previous abortions during the lactation) was 1.41 per 100 cow-months at risk. These results suggest that bovine abortions are an important ongoing problem in dairy farms in Costa Rica with potentially detrimental effects on the reproductive and productive performance of cows and may be representative of other specialized tropical dairy systems in Latin America.

The objective was to compare pregnancy per service event (P/S) in lactating dairy cows following timed artificial insemination (AI) or timed embryo transfer (ET) using either fresh or frozen in vitro-produced embryos. Oocytes were collected once per week for up to 9 wk using transvaginal ovum pick-up from elite dairy donors (ET-DAIRY; n = 40; Holstein-Friesian and Jersey) and elite beef donors (ET-ELITE-BEEF; n = 21; Angus). Both ET-DAIRY and ET-ELITE-BEEF donors consisted of heifers and cows. In addition, oocytes were collected from the ovaries of beef heifers of known pedigree following slaughter at a commercial abattoir (ET-COMM-BEEF; n = 119). Following in vitro maturation and fertilization, presumptive zygotes were cultured in vitro to the blastocyst stage. Grade 1 blastocysts were either transferred fresh or frozen for on-farm thawing and direct transfer. A total of 1,106 recipient cows (all lactating, predominantly Holstein-Friesian) located on 16 herdlets were blocked based on parity, calving date, and Economic Breeding Index, and randomly assigned to receive AI (n = 243) or ET (n = 863) after estrous synchronization with a 10-d Progesterone-synch protocol. Cows assigned to ET were further randomized to receive fresh (n = 187) or frozen (n = 178) ET-ELITE-BEEF embryos, fresh (n = 169) or frozen (n = 162) ET-DAIRY embryos, or fresh (n = 80) or frozen (n = 87) ET-COMM-BEEF embryos. Pregnancy was diagnosed using transrectal ultrasound on d 32 to 35 after synchronized ovulation and confirmed on d 62 to 65, at which time fetal sex was determined. Pregnancy per service event at d 32 was not different between AI (48.8%) and ET (48.9%) and did not differ between dairy and beef embryos (50.3% vs. 48.1%, respectively). However, P/S was less on d 32 following transfer of frozen embryos (41.6%) compared with fresh embryos (56.1%). Pregnancy loss between d 32 and 62 was greater for ET (15.1%) compared with AI (4.7%), with greater losses observed for frozen beef (18.5%)

MicroRNAs (miRNAs) are small highly conserved non-coding RNA molecules that orchestrate a wide range of biological processes through post-transcriptional regulation of gene expression. During development, miRNAs play a key role in driving embryo patterning and morphogenesis in a specific and stage-dependent manner. Here, we investigated whether sperm from bulls with different fertilizing ability in vitro influence blastocyst quality and miRNA content. Results demonstrate that blastocysts obtained using sperm from high fertility sires (H group) display significantly greater cleavage and blastocyst development as well as greater transcript abundance in blastocysts for the developmental competence markers CDX2, KRT8, NANOG, OCT4, PLAC8, PTGS2, SOX17, and SOX2, compared to blastocysts generated using sperm from low fertility sires (L group). In parallel, high throughput deep sequencing and differential expression studies revealed that H blastocysts exhibit a greater miRNA content compared to L blastocysts, with hsa-miR-4755-5p and hsa-miR-548d-3p uniquely detected in the H group, and greater abundance of hsa-miR-1225-3p in the H group. Gene ontology (GO) and KEGG pathway analyses indicated that the 3 differentially expressed miRNAs identified are involved in the regulation of many biological mechanisms with a key role in aspects of early embryo development, including transcriptional regulation, cellular biosynthesis, nucleic acid metabolism, cellular differentiation, apoptosis, cytoskeleton remodeling, cell-to-cell interactions, and endocytosis. Overall, our results indicate that sperm fertilizing ability influences blastocyst developmental ability and miRNA content. In addition, we demonstrate an association between blastocyst quality and miRNA content, thus suggesting the possibility to score miRNA expression as biomarkers for improved routine embryo selection technologies to support assisted reproductive efforts.

Schistosoma reflexum (SR) is a lethal congenital syndrome characterized by U-shaped dorsal retroflexion of the spine and exposure of abdominal viscera. SR is usually associated with severe dystocia. The syndrome is thought to be inherited as a Mendelian trait. We collected a series of 23 SR-affected calves from four breeds (20 Holstein, one Red Danish, one Limousin, one Romagnola) and performed whole-genome sequencing (WGS). WGS was performed on 51 cattle, including 14 cases with parents (trio-based; Group 1) and nine single cases (solo-based; Group 2). Sequencing-based genome-wide association studies with 20 Holstein cases and 154 controls showed no association (above Bonferroni threshold; P-value<3 ×10-09). Assuming a monogenic recessive inheritance, no region of shared homozygosity was observed, suggesting heterogeneity. Alternatively, the presence of possible dominant acting de novo mutations were assessed. In Group 1, heterozygous private variants, absent in both parents, were found in seven cases. These involved the ACTL6A, FLNA, GLG1, IQSEC2, MAST3, MBTPS2, and MLLT1 genes. In addition, heterozygous private variants affecting the genes DYNC1LI1, PPP2R2B, SCAF8, SUGP1, and UBP1 were identified in five cases from Group 2. The detected frameshift and missense variants are predicted to cause haploinsufficiency. Each of these 12 affected genes belong to the class of haploinsufficient loss-of-function genes or are involved in embryonic and pre-weaning lethality or are known to be associated with severe malformation syndromes in humans and/or mice. This study presents for the first time a detailed genomic evaluation of bovine SR, suggesting that independent de novo mutations may explain the sporadic occurrence of SR in cattle.

Background: Satellite cells are myogenic precursor cells in adult skeletal muscle and play a crucial role in skeletal muscle regeneration, maintenance, and growth. Like embryonic myoblasts, satellite cells have the ability to proliferate, differentiate, and fuse to form multinucleated myofibers. In this study, we aimed to identify additional transcription factors that control gene expression during bovine satellite cell proliferation and differentiation. Results: Using chromatin immunoprecipitation followed by sequencing, we identified 56,973 and 54,470 genomic regions marked with both the histone modifications H3K4me1 and H3K27ac, which were considered active enhancers, and 50,956 and 59,174 genomic regions marked with H3K27me3, which were considered repressed enhancers, in proliferating and differentiating bovine satellite cells, respectively. In addition, we identified 1,216 and 1,171 super-enhancers in proliferating and differentiating bovine satellite cells, respectively. Analyzing these enhancers showed that in proliferating bovine satellite cells, active enhancers were associated with genes stimulating cell proliferation or inhibiting myoblast differentiation whereas repressed enhancers were associated with genes essential for myoblast differentiation, and that in differentiating satellite cells, active enhancers were associated with genes essential for myoblast differentiation or muscle contraction whereas repressed enhancers were associated with genes stimulating cell proliferation or inhibiting myoblast differentiation. Active enhancers in proliferating bovine satellite cells were enriched with binding sites for many transcription factors such as MYF5 and the AP-1 family transcription factors; active enhancers in differentiating bovine satellite cells were enriched with binding sites for many transcription factors such as MYOG and TFAP4; and repressed enhancers in both proliferating and differentiating bovine satellite cells were enriched with binding site

Dairy cattle are typically disbudded or dehorned. Little is known, however, about the biological function and role of horns during thermoregulatory processes in cattle, and thus about the potential physiological consequences of horn removal. Anecdotal evidence suggests that dairy cow horns increase in temperature during rumination, and few studies on other bovid species indicate that horns aid thermoregulation. The objective of this study was, therefore, to elucidate a possible thermoregulatory function of the horns in dairy cattle. Using non-invasive infrared thermography, we measured the superficial temperature of the horns, eyes, and ears of 18 focal cows on three different farms in a temperate climate zone under various environmental circumstances. Observations of social and non-social behaviours were conducted as well. Based on environmental temperature, humidity, and wind speed, the heat load index (HLI) was calculated as a measure of the heat load experienced by a cow. The temperature of the horns increased by 0.18 °C per unit HLI, indicating that horns serve the dissipation of heat. Dehorned cows had higher eye temperatures than horned cows, though this result should be interpreted with caution as the low sample size and experimental setup prevent casual conclusions. We did not, however, find changes in horn temperature during rumination, nor with any other behaviours. Our study thus supports a role of horns in thermoregulation, but not related to rumination. These results should be considered when assessing the potential consequences of horn removal, a painful procedure.

Although bovine respiratory syncytial virus (BRSV) infection has been reported in cattle in Argentina, it has not been associated with pneumonia in Argentina. We report here 5 cases of bovine pneumonia associated with BRSV. Autopsies were performed on 35 beef cattle with gross and/or microscopic lesions of pneumonia from 3 commercial feedlots. Lung samples in 5 of 35 animals were BRSV-positive by reverse-transcription nested PCR. The lungs of 2 of these 5 animals were coinfected with Mannheimia haemolytica, and 1 with bovine viral diarrhea virus 1. Microscopically, the lungs of 3 of the 5 BRSV PCR-positive animals had fibrinosuppurative bronchopneumonia, with or without pleuritis; 2 of the 5 had interstitial pneumonia. We conclude that BRSV is part of the bovine respiratory disease complex in Argentina.

Bovine brucellosis is a zoonotic disease that causes substantial economic losses and strongly impacts public health. Though it has been eradicated in many developed countries, it is still endemic in developing countries like Ethiopia: The study's objectives were to estimate the seroprevalence of bovine brucellosis, determine the risk factors, quantify and assess the knowledge, attitude, and behavior of cattle owners in a few selected areas of Ethiopia's Gambella region. Lare and Jikawo were the two districts of the Gambella Region selected purposively. Kebeles, study animals and peasant associations were randomly chosen. A total of 384 serum samples from 70 herds were collected and screened using the Rose Bengal Plate Test and confirmed using the Complement Fixation Test. A semi-structured questionnaire survey was used to assess the risk factors for the seroprevalence of bovine brucellosis and the knowledge, attitude and practice of farmers in the study areas about the disease. The seroprevalence of brucellosis was summarized using descriptive statistics, and the association between risk factors, and seroprevalence of brucellosis was evaluated using logistic regression. The principal findings of the current study showed that individual and herd level seroprevalence of brucellosis using the Rose Bengal Plate test was 6.8% (26/384) and 24.3% (17/70), respectively, and the respective confirmation by complement fixation test3.1% (12/384) and 12.9% (9/70). Among the risk factors, herd size and the presence of other species had statistically significant associations (p<0.05) with Brucella seropositivity. Female cattle with more parity and those with abortion history had higher odds of Brucella antibodies compared to their counterparts. Although the overall respondents' knowledge, attitude, and practice were 66.4%, most were unaware that the disease was zoonotic, the ability of the disease to cause abortion, and the mode of the disease's transmission. Most respondents a

type:Article, Mycoplasma bovis (M. bovis) is a significant worldwide pathogen of cattle. Neutrophils have an important role in the innate immune response during infection with M. bovis. However, even though neutrophils accumulate in M. bovis infection, the interaction of M. bovis and neutrophils has not been fully elucidated. We attempted to elucidate the innate immune response of neutrophils stimulated with M. bovis and evaluate the transcriptome and functional analysis of bovine neutrophils stimulated with M. bovis. Proinflammatory cytokines, such as inducible nitric oxide (iNOS), which was the most increased gene in transcriptome analysis, were increased in quantitative polymerase chain reaction analysis of bovine neutrophils stimulated with live or heat-killed M. bovis. Nitric oxide and intracellular reactive oxygen species production of neutrophils stimulated with M. bovis was significantly increased. Neutrophils stimulated with M. bovis showed an increased ratio of nonapoptotic cell death compared to unstimulated controls. We demonstrated that neutrophil extracellular traps (NETs) formation was not recognized in neutrophils stimulated with live M. bovis. However, heat-killed M. bovis induced NETs formation. We also showed the interaction with M. bovis and bovine neutrophils regarding proinflammatory cytokine gene expression and functional expression related to NETs formation. Live and killed M. bovis induced innate immune responses in neutrophils and had the potential to induce NETs formation, but live M. bovis escaped NETs.

Biological fluids, the most complex blends, have compositions that constantly vary and cannot be molecularly defined1. Despite these uncertainties, proteins fluctuate, fold, function and evolve as programmed2-4. We propose that in addition to the known monomeric sequence requirements, protein sequences encode multi-pair interactions at the segmental level to navigate random encounters5,6; synthetic heteropolymers capable of emulating such interactions can replicate how proteins behave in biological fluids individually and collectively. Here, we extracted the chemical characteristics and sequential arrangement along a protein chain at the segmental level from natural protein libraries and used the information to design heteropolymer ensembles as mixtures of disordered, partially folded and folded proteins. For each heteropolymer ensemble, the level of segmental similarity to that of natural proteins determines its ability to replicate many functions of biological fluids including assisting protein folding during translation, preserving the viability of fetal bovine serum without refrigeration, enhancing the thermal stability of proteins and behaving like synthetic cytosol under biologically relevant conditions. Molecular studies further translated protein sequence information at the segmental level into intermolecular interactions with a defined range, degree of diversity and temporal and spatial availability. This framework provides valuable guiding principles to synthetically realize protein properties, engineer bio/abiotic hybrid materials and, ultimately, realize matter-to-life transformations.

The transmission of genetic information across generations depends on the integrity of the germline. Primordial germ cells (PGCs) are the embryonic precursors of mature germ cells, spermatozoa and oocytes, and their proper development is essential for reproductive success. PGCs are initially formed in extraembryonic regions and migrate to the developing gonads. Through a series of mitotic divisions, meiosis, and differentiation, PGCs transform into fully mature gametes that carry the genetic material required for the creation of a new individual upon fertilization. The NANOS gene family has been found to play a critical role in germ cell development across various organisms, including mammals, with specific expression in germ cells. Through murine studies, Nanos3 has been identified as a crucial regulator of germ cell development in both sexes, protecting germ cells from apoptosis during migration and colonization of the gonadal ridge. In contrast, Nanos2 is specifically involved in male germ cell differentiation and maintenance of the spermatogonial stem cell population. These genes exert their control through translational repression of target mRNAs, influencing the expression of key factors involved in meiosis and germ cell differentiation. Recent studies in pigs, sheep, and cattle have shown that NANOS2 knockout (KO) animals replicate the male-specific germline ablation observed in mice, while female germline development remains unaffected. Similarly, NANOS3 KO livestock, including male and female pigs and a female bovine fetus, exhibited a complete loss of germ cells but normal gonadal development. Notably, live NANOS3 KO cattle have not been generated to date, and the specific role of NANOS3 in male cattle has yet to be explored. Collectively, these findings suggest that NANOS3 KO livestock could serve as potential hosts for germline complementation, a technique where donor cells from one genetic background replace the germline of a sterile host with a differe

Milk oligosaccharides (MOs) can be prebiotic and antiadhesive, while fatty acids (MFAs) can be antimicrobial. Both have been associated with milk microbes or mammary gland inflammation in humans. Relationships between these milk components and milk microbes or inflammation have not been determined for cows and could help elucidate a novel approach for the dairy industry to promote desired milk microbial composition for improvement of milk quality and reduction of milk waste. We aimed to determine relationships among milk microbiota, MFAs, MOs, lactose, and somatic cell counts (SCC) from Holstein cows, using our previously published data. Raw milk samples were collected at three time points, ranging from early to late lactation. Data were analyzed using linear mixed-effects modeling and repeated-measures correlation. Unsaturated MFA and short-chain MFA had mostly negative relationships with potentially pathogenic genera, including Corynebacterium, Pseudomonas, and an unknown Enterobacteriaceae genus but numerous positive relationships with symbionts Bifidobacterium and Bacteroides. Conversely, many MOs were positively correlated with potentially pathogenic genera (e.g., Corynebacterium, Enterococcus, and Pseudomonas), and numerous MOs were negatively correlated with the symbiont Bifidobacterium. The neutral, nonfucosylated MO composed of eight hexoses had a positive relationship with SCC, while lactose had a negative relationship with SCC. One interpretation of these trends might be that in milk, MFAs disrupt primarily pathogenic bacterial cells, causing a relative increase in abundance of beneficial microbial taxa, while MOs respond to and act on pathogenic taxa primarily through antiadhesive methods. Further research is needed to confirm the potential mechanisms driving these correlations. IMPORTANCE Bovine milk can harbor microbes that cause mastitis, milk spoilage, and foodborne illness. Fatty acids found in milk can be antimicrobial and milk oligosaccharides can

Blackleg is a common cause of death in cattle, mostly caused by the bacterium Clostridium chauvoei. Cardiac lesions were traditionally considered uncommon in cases of blackleg in cattle until a 2018 study reported otherwise. This study was aimed at determining the prevalence of cardiac disease among cattle that died of blackleg in Tennessee, USA. The outcome of this study would reinforce the importance of assessing cardiac lesions in suspected cases of blackleg in cattle. The University of Tennessee Veterinary Medical Center database searched for cattle with a confirmed diagnosis of blackleg necropsied between 2004 and 2018. Of the 120 necropsy reports, 37 had a diagnosis of blackleg. Histology slides of skeletal muscle (26/37) and the heart (26/37) were reviewed to confirm the presence of supportive lesions. Of the 37 cases of blackleg identified, 26 animals (70.3%) had cardiac lesions, including 4 (10.8%) that had only cardiac involvement without skeletal muscle lesions. Specifically, (5.4%; 2/37) had only necrotizing myocarditis; (13.5%; 5/37) had only fibrinous or fibrinosuppurative pericarditis, epicarditis, or endocarditis; (51.4%; 19/26) had a combination of myocarditis and pericarditis, epicarditis, or endocarditis; and (29.7%; 11/37) had no lesions. Furthermore, of the 26 cases with cardiac lesions, 24 cases had gross lesions, while 2 cases were identified only by microscopic examination. This indicates that gross examination alone is insufficient to identify cardiac involvement in blackleg cases in cattle. Contrary to traditional perceptions, cardiac lesions in cases of bovine blackleg could be as high as 70% and are most often associated with skeletal muscle lesions. The prevalence of cardiac lesions in cases of blackleg in cattle may be higher when the heart is examined microscopically than if it is only evaluated grossly. Pathologists should specifically evaluate the heart for lesions in suspected cases of blackleg in cattle and utilize microscopic exam

BACKGROUND: Rumen juice analysis (RJA) involves analysis of a 10mL sample within minutes after sampling. However, it can be challenging to collect 10 mL of rumen juice (RJ) from some ruminants, and clinical circumstances can delay RJA. OBJECTIVES: Quantify the effect of sample volume (2, 5, 10, 50, and 100 mL), and time-to-analysis (0, 30, and 60 minutes) on RJA. ANIMALS: Cannulated cow. METHODS: Observational experimental study. Two liters of RJ were collected at 26 separate times. The samples were subdivided into 2 duplicates of each sample volume at each sampling time; and analyzed at 0, 30, and 60 minutes after collection. Rumen juice analysis included pH measurement, methylene blue reduction time (MBRT), and protozoal motility. RESULTS: The pH of 2 and 5 mL samples was significantly (P = .01) higher than the pH of 50 and 100 mL samples at all time points. The MBRT was significantly lower (faster bacterial reduction) for 100 mL samples compared to all other samples at 0 minute and to 2, 5, and 50 mL samples at 30 min. The pH and MBRT at 60 minutes were significantly higher than at 0 minute for all volumes (P < .05 and P < .01, respectively). For large protozoa, small sample volumes (2 and 5 mL) had significantly lower protozoal motility (scores of 5 and 4.5, respectively) compared to 100 mL samples at 60 minutes (score of 4; P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE: Interpretation of RJA could be affected by small sample volumes and delays to analysis. Sample volumes of ≥10 mL analyzed within 30 minutes after collection are recommended.

Fibroblast growth factor 21 (FGF21) has been identified in multiple mammalian species as a molecular marker of energy metabolism while also providing negative feedback to the gonads. However, the role of FGF21 in regulating the energetic and reproductive physiology of beef heifers and cows has yet to be characterized. Herein, we investigated the temporal concentrations of FGF21 in female beef cattle from the prepubertal period to early lactation. Circulating concentrations of FGF21, non-esterified fatty acids, plasma urea nitrogen, glucose, and progesterone were assessed. Ultrasonography was employed to determine the onset of puberty and resumption of postpartum ovarian cyclicity as well as to measure backfat thickness. Finally, cows and calves underwent the weigh-suckle-weigh technique to estimate rate of milk production. We have revealed that FGF21 has an expansive role in the physiology of female beef cattle, including pubertal onset, adaptation to nutritional transition, rate of body weight gain, circulating markers of metabolism, and rate of milk production. In conclusion, FGF21 plays a role in physiological functions in beef cattle that can be applied to advance the understanding of basic scientific processes governing the nutritional regulation of reproductive function but also provides a novel means for beef cattle producers to select parameters of financial interest.

Fascioliasis is one of the most prevalent and economically significant parasitic illnesses of domestic animals, particularly cattle, sheep, goats, and man. It is particularly widespread in countries with heavy cattle production especially places with low interest in vector-related diseases. Therefore, the study was designed to investigate the prevalence of this parasitic disease among the cattle slaughtered in the selected abattoirs in Oyo, Oyo State, Nigeria. Two hundred and fifty (250) faecal samples were collected from the rectum of the slaughtered cattle. The samples were analyzed using the Formol-ether Concentration technique. Also, post mortem examination of the liver and other organs of the slaughtered cattle (250) at the abbattior were also examined for Fasciola infestation. The data were were analyzed with Chi-square at 5% level of significance using SPSS. It was observed that 77 (30.8%) were positive to fascioliasis out of the 250 slaughtered cattle examined. The prevalence of the infection based on the sex of the cattle was found to be statistically significant (p = 0.001).The percentage of fascioliasis depending on the breed of the cattle was observed to be lowest (25%) in Sokoto Gudali and highest (33.33%) in White Fulani. The analysis implied that there was a strong association between infection and cattle breeds. Prevalence of fascioliasis based on the estimated age of animals was not statistically significant however; animals aged 3 years and 6 months had the highest percentage (54.1%) while those within 2 years and 6 months had no cases of fascioliasis. Fascioliasis is an endemic illness in the study area among cattle slaughtered for consumption. This suggests the possibility of human infestation through consumption especially when it is under-processed. The need for health policy to ensure slaughtering of healthy cattle become important to ensure safe public health especially through consumption of meat. Also, public health intervention through mas

Indicine and taurine subspecies present distinct morphological traits as a consequence of environmental adaptation and artificial selection. Although the two subspecies have been characterized and compared at genome-wide level and at specific loci, their epigenetic diversity has not yet been explored. In this work, Reduced Representation Bisulphite Sequencing (RRBS) profiling of the taurine Angus (A) and indicine Nellore (N) cattle breeds was applied to identify methylation differences between the two subspecies. Genotyping by sequencing (GBS) of the same animals was performed to detect single nucleotide polymorphisms (SNPs) at cytosines in CpG dinucleotides and remove them from the differential methylation analysis. A total of 660,845 methylated cytosines were identified within the CpG context (CpGs) across the 10 animals sequenced (5 N and 5 A). A total of 25,765 of these were differentially methylated (DMCs). Most DMCs clustered in CpG stretches nearby genes involved in cellular and anatomical structure morphogenesis. Also, sequences flanking DMC were enriched in SNPs compared to all other CpGs, either methylated or unmethylated in the two subspecies. Our data suggest a contribution of epigenetics to the regulation and divergence of anatomical morphogenesis in the two subspecies relevant for cattle evolution and sub-species differentiation and adaptation.

Several key developmental events are associated with early embryonic pregnancy losses in beef and dairy cows. These developmental problems are observed at a greater frequency in pregnancies generated from in-vitro-produced bovine embryos. This review describes critical problems that arise during oocyte maturation, fertilization, early embryonic development, compaction and blastulation, embryonic cell lineage specification, elongation, gastrulation, and placentation. Additionally, discussed are potential remediation strategies, but unfortunately, corrective actions are not available for several of the problems being discussed. Further research is needed to produce bovine embryos that have a greater likelihood of surviving to term.

Ungulate embryos undergo critical cell differentiation and proliferation events around and after blastocyst hatching. Failures in these processes lead to early pregnancy losses, which generate an important economic impact on farming. Conventional embryo culture media, such as SOF, are unable to support embryo development beyond hatching. In contrast, N2B27 medium supports early post-hatching development, evidencing a swift in embryonic nutritional requirements during this developmental window. Here, we investigate if earlier exposure to N2B27 could improve embryo development after hatching. Embryo culture in N2B27 from day (D) 5, 6 or 7 significantly enhanced complete hypoblast migration (>45 vs. ∼24%) and epiblast development into an embryonic disc (ED)-like structure at D12 (>40 vs. 23%), compared to embryos cultured in SOF up to D9. Culture in N2B27 from D5 significantly increased epiblast and hypoblast cell number in D8 blastocysts, but post-hatching embryos cultured in N2B27 from D5 or 6 frequently showed a disorganized distribution of epiblast cells. In conclusion, bovine embryo culture in N2B27 from D7 onwards improves subsequent post-hatching development. This improved fully in vitro system will be very useful to functionally explore cell differentiation mechanisms and the bases of early pregnancy failures without requiring animal experimentation.

Despite passing routine laboratory tests for semen quality, bulls used in artificial insemination exhibit significant variation in fertility. Routine analysis of fertility data identified a dairy bull with extreme subfertility (10% pregnancy rate). To characterize the subfertility phenotype, a range of in vitro, in vivo, and molecular assays were carried out. Sperm from the subfertile bull exhibited reduced motility and severely reduced caffeine-induced hyperactivation compared to controls. Ability to penetrate the zona pellucida, cleavage rate, cleavage kinetics, and blastocyst yield after IVF or AI were significantly lower than in control bulls. Whole-genome sequencing from semen and RNA sequencing of testis tissue revealed a critical mutation in adenylate kinase 9 (AK9) that impaired splicing, leading to a premature termination codon and a severely truncated protein. Mice deficient in AK9 were generated to further investigate the function of the gene; knockout males were phenotypically indistinguishable from their wild-type littermates but produced immotile sperm that were incapable of normal fertilization. These sperm exhibited numerous abnormalities, including a low ATP concentration and reduced motility. RNA-seq analysis of their testis revealed differential gene expression of components of the axoneme and sperm flagellum as well as steroid metabolic processes. Sperm ultrastructural analysis showed a high percentage of sperm with abnormal flagella. Combined bovine and murine data indicate the essential metabolic role of AK9 in sperm motility and/or hyperactivation, which in turn affects sperm binding and penetration of the zona pellucida. Thus, AK9 has been found to be directly implicated in impaired male fertility in mammals.

Classical bovine spongiform encephalopathy (BSE) in cattle was caused by the recycling and feeding of meat and bone meal contaminated with a transmissible spongiform encephalopathy (TSE) agent but its origin remains unknown. This study aimed to determine whether atypical scrapie could cause disease in cattle and to compare it with other known TSEs in cattle. Two groups of calves (five and two) were intracerebrally inoculated with atypical scrapie brain homogenate from two sheep with atypical scrapie. Controls were five calves intracerebrally inoculated with saline solution and one non-inoculated animal. Cattle were clinically monitored until clinical end-stage or at least 96 months post-inoculation (mpi). After euthanasia, tissues were collected for TSE diagnosis and potential transgenic mouse bioassay. One animal was culled with BSE-like clinical signs at 48 mpi. The other cattle either developed intercurrent diseases leading to cull or remained clinical unremarkable at study endpoint, including control cattle. None of the animals tested positive for TSEs by Western immunoblot and immunohistochemistry. Bioassay of brain samples from the clinical suspect in Ov-Tg338 and Bov-Tg110 mice was also negative. By contrast, protein misfolding cyclic amplification detected prions in the examined brains from atypical scrapie-challenged cattle, which had a classical BSE-like phenotype. This study demonstrates for the first time that a TSE agent with BSE-like properties can be amplified in cattle inoculated with atypical scrapie brain homogenate.

Arachidonic acid (AA) is the precursor of prostaglandins, which may play autocrine roles during early embryo development.

BACKGROUND: Rearing replacement heifers is pivotal for the dairy industry and is associated with high input costs for the preweaned calves, due to their higher susceptibility to diseases. Ensuring calf health and viability calls for systematic approaches in order to mitigate the costs induced by managing sick calves and to ensure animal welfare. The objective of this study was to develop a systematic and feasible health-monitoring tool for bovine dairy calves based on repeated clinical observations and diagnostic results of calves at three time points; the 1st (T0), the 3rd (T1) and the 12th (T3) week of age. The study included observations from 77 dairy heifer calves in nine Danish commercial dairy herds. Immunisation status was assessed by serum Brix% at T0. Clinical scoring included gastrointestinal disease (GD) and respiratory disease (RD). The average daily weight gain (ADWG) was estimated from heart-girth measurements. Pathogen detection from nasal swabs and faecal samples were analysed for 16 respiratory and enteric pathogens by means of high-throughput real time-PCR. All measures obtained in each herd were visualised in a panel to follow the health status of each calf over time.RESULTS: The individual clinical observations combined with diagnostic information from immunisation and pathogen detection form each enrolled calf are presented in a herd dashboard illustrating the health status over the study period. This monitoring revealed failure of passive transfer (Brix% < 8.1) in 31% of the 77 enrolled calves, signs of severe GD peaked at T0 with 20% affected calves, while signs of severe RD peaked at T2 with 42% affected calves. ADWG over the first eight weeks was estimated to be 760 g (± 190 g). Pathogen profiles varied between herds.CONCLUSIONS: The large variation in both clinical disease and pathogen occurrence across herds emphasizes the need for herd specific monitoring. Combining the results of the present study from measures of imm

MicroRNAs (miRNAs) are small, single-stranded, non-coding RNA molecules of 22-24 nucleotides that regulate gene expression. In the last decade, miRNAs have been described in sperm of several mammals, including cattle. It is known that miRNAs can act as key gene regulators of early embryogenesis in mice and humans; however, little is known about the content, expression, and function of sperm-borne miRNAs in early bovine embryo. In this study, total sperm RNA was isolated from 29 cryopreserved sperm samples (each coming from a separate bull) using a RNeasy kit and treatment with DNase I. RNA concentration and purity were determined through an Epoch spectrophotometer and an Agilent Bioanalyzer. The expression of 10 candidate miRNAs in bovine sperm (bta-miR-10a, bta-miR-10b, bta-miR-138, bta-miR-146b, bta-miR-19b, bta-miR-26a, bta-miR-34a, bta-miR-449a, bta-miR-495 and bta-miR-7), previously identified in testis and/or epididymis, was evaluated with RT-qPCR. The cel-miR-39-3p was used as a spike-in exogenous control. Nonparametric Mann-Whitney tests were run to evaluate which miRNAs were differentially expressed between bulls with high fertility [HF; non-return rates (NRR) ranging from 39.5 to 43.5] and those with subfertility (SF; NRR ranging from 33.3 to 39.3). Several sperm functionality parameters (e.g., viability, membrane stability or oxygen consumption, among others) were measured by multiplexing flow cytometry and oxygen sensing technologies.RNA concentration and purity (260/280 nm ratio) (mean ± SD) from the 29 samples were 99.3 ± 84.6 ng/µL and 1.97 ± 0.72, respectively. Bioanalyzer results confirmed the lack of RNA from somatic cells. In terms of the presence or absence of miRNAs, and after applying the Livak method, 8 out of 10 miRNAs (bta-miR-10b, -138, -146b

Endocrine disrupting chemicals (EDCs) can interfere with normal hormonal action and regulation. Exposure of women to EDCs has been associated with adverse reproductive health outcomes. The assays currently used to identify EDCs that elicit female reproductive toxicity lack screening tests that address effects on the maturation of oocytes, a process that enables them to be fertilized and develop into embryos. Here, a screening method employing the bovine model of in vitro oocyte maturation and embryo production is described. Endpoints explored address important events in oocyte maturation and developmental competence acquisition. To test the method, the effects of the known human EDC diethylstilbestrol (DES; an estrogen receptor agonist) were evaluated in a range of concentrations (10 -9 M, 10 -7 M, 10 -5 M). Bovine oocytes were exposed to DES during in vitro maturation (IVM) or embryos were exposed during in vitro embryo culture (IVC). The endpoints evaluated included nuclear maturation, mitochondrial redistribution, cumulus cell expansion, apoptosis, and steroidogenesis. DES-exposed oocytes were fertilized to record embryo cleavage and blastocyst rates to uncover effects on developmental competence. Similarly, the development of embryos exposed to DES during IVC was monitored to assess the impact on early embryo development. Exposure to 10 -9 M or 10 -7 M DES did not affect the endpoints addressing oocyte maturation or embryo development. However, there were considerable detrimental effects observed in oocytes exposed to 10 -5 M DES. Specifically, compared to vehicle-treated oocytes, there was a statistically significant reduction in nuclear maturation (3% vs 84%), cumulus expansion (2.8-fold vs 3.6-fold) and blastocyst rate (3% vs 32%). Additionally, progesterone and pregnenolone concentrations measured in IVM culture media were increased. The screening method described here shows that bovine oocytes were sensitive to the action of this particular chemical (i.e

Northern Ireland has a comprehensive bTB programme which faces many challenges. The main subject of this dissertation, chronic bTB herds, is one such example, bringing together many factors which interact in a complex manner providing a difficult backdrop in which to apply control policies. The challenges faced include insufficiencies in diagnostic techniques, programme fatigue among farmers who feel a lack of empowerment about their circumstances and an agricultural industry evolving in ways which potentially make disease control more difficult. However, even though the challenges are great it will only be through logical and well thought out science, including social science, that bTB eradication can be achieved.

Precise regulation of gene expression ensures oocytes and embryos accomplish the dynamic events required for successful oocyte maturation and early embryo development. However, most studies of gene expression regulation have focused on the mouse. In this respect, we used the cow as an alternative mammalian model to study gene expression regulation during oocyte maturation and early embryo development. We described dynamic changes in gene expression and poly(A) tail length during bovine oocyte maturation and early embryo development. As a result of these changes, the reference genes most suitable for gene expression normalization are different when different reverse transcription priming methods are employed. On the other hand, epigenetic alterations and differential regulation of transcription factors affect gene expression at the transcriptional level in embryos. One of the major epigenetic events-XCI, is initiated at morula stage in female bovine embryos. However, the initiation of XCI does not lead to complete down-regulation of all X-linked genes. The expression of the transcription factor CDX2 in bovine embryos is up regulated after exposure to LPA. But LPA stimulation does not change embryo constitution in terms of percentages of cells committed to one or another lineage. Overall, a better understanding of gene expression regulation during ocoyte maturation and early embryo development broadens our fundamental knowledge of mammalian embryonic development and will improve our understanding of the requirements for cell lineage determination and pluripotency, and the short and longer term consequences of epigenetic disturbances resulting from sub-optimal maternal health and nutrition or in vitro fertilization and embryo culture conditions.

Neospora caninum is recognised for causing cattle abortion, provoking severe economic losses in the livestock industry worldwide. The aim of the present study was to evaluate the reactivation and foetal infection in pregnant heifers inoculated with live N. caninum tachyzoites before puberty. A total of 15 30-month-old pregnant heifers were allocated into four groups: animals inoculated with live tachyzoites of NC-Argentina LP1 isolate before puberty and challenged with live tachyzoites of NC-1 strain at 210 days of gestation (DG) (Group A); animals mock inoculated before puberty and challenged with NC-1 strain at 210 DG (Group B), animals inoculated before puberty but not subsequently challenged (Group C); and noninfected and nonchallenged animals (Group D). The results of this study showed that 100% of animals infected before puberty (Groups A and C) suffered reactivation of the infection at the seventh month of gestation. In addition, in three and two calves from Groups A and C, respectively, congenital infection was confirmed. Interestingly, we provide evidence that the use of live N. caninum tachyzoites in young animals as a strategy to induce protection is neither safe nor effective., Research Grants from Agencia Nacional de Promoción Científica y Tecnológica y FONCyT, INTA, Depto. de Sanidad Animal, Fac. de Veterinaria, TRUE, pub

Heat stress is detrimental across many, if not most aspects of animal agriculture. Heat stress can have direct effects on the animal, effects on their environment and effects on the feedstuffs they consume. The work presented here will address direct effects on the animal (using dairy cattle) and effects on their feed (using pigs). Dairy cattle were chosen to study direct effects on the animal because they exhibit unique metabolic adaptions during heat stress. One adaptation of interest is a heat-stress induced state of hyperinsulinemia and hypoglycemia while self-limiting feed intake. In regards to effects on feedstuffs, high ambient temperatures are associated with elevated concentrations of mycotoxins in cereal grains. Mycotoxins are problematic because, at sufficient concentrations, they induce specific, toxic effects. Zearalenone is one such mycotoxin that is particularly problematic for swine, as it is a potent phytoestrogen. As such, it can reduce productivity by disrupting reproductive processes. Although these topics are disparate, the overarching goal of this work is to improve agricultural animal productivity during periods of heat stress. Overall, the three objectives of this thesis were to: 1) isolate the production-related effects of hyperinsulinemia with hypoglycemia from heat stress, 2) determine whether glucose supplementation during heat stress could improve or rescue milk production during heat stress, and finally, 3) investigate reproductive tract morphology following different durations of zearalenone consumption in peri-pubertal gilts. The first experiment compared the effects of thermoneutral, thermoneutral + hyperinsulinemic-hypoglycemic clamp (HHC), environmental heat stress, and heat stress + euglycemic clamp (EC) on milk production, milk components, and circulating glucose concentrations. Milk production, as expected, did decrease under heat stress when compared to thermoneutral conditions. Milk production during the HHC was intermediate

Scientists have developed techniques like ovum pick up (OPU) and follicular ablation as a large source of oocytes for creating IVP bovine embryos. These techniques have allowed for more efficient dissemination of valuable female genetics compared to traditional artificial insemination or embryo flushing. IVP embryos have lower embryo development rates and quality, leading to lower pregnancy rates. Nerve growth factor-beta (NGF), however, has been previously shown to improve 48-hour cleavage rates and the number of hatching/ hatched blastocysts out of total presumptive zygotes. We hypothesize that NGF will improve IVP embryo development by positively influencing cleavage and blastocyst rates. The first two experiments' objectives were to determine the effect of recombinant bovine (60 or 90% purity) and human NGF (97% purity) supplementation during in vitro fertilization on 24- and 48-hour cleavage and day 8 blastocyst development rates. The objective of the third experiment was to assess the effect of the supplementation of bovine NGF (90% purity) on heat shocked and non-heat shocked in vitro-matured cumulus-oocyte complexes, assessing cleavage rates at 48 and 72 hours post insemination and blastocyst development rates. The results of experiment 1 show there were no differences between any of the three treatment groups (bNGF60, hNGF95, and control) for 24 hour (P = 0.66) or 48 hour (P = 0.33) embryonic cleavage rates. Additionally, there were no differences between treatments in the total percentage of blastocysts per oocyte (P = 0.91) or the percentage of blastocysts per cleaved embryo (P = 0.32). The results of experiment 2 also showed no differences between any of the three treatment groups (bNGF90, hNGF95, and control) for 24 hour (P = 0.16) or 48 hour (P = 0.18) embryonic cleavage rates. Additionally, there were no differences between treatments in the total percentage of blastocysts per oocyte (P = 0.42) or the percentage of blastocysts per cleaved embryo (P =

Dairy cattle characteristically exhibit decreased milk yield and reproductive performance, as well as increased uterine infection rates during periods of high stress. Chromium supplementation has demonstrated efficacy as a feed additive capable of reducing the detrimental effects of stress. As such, its application in dairy production may help to alleviate economic losses associated with seasonal heat stress and the stress experienced during the early postpartum period. Therefore, the objective of the work described in this thesis was to evaluate the potential benefits of short-duration, high-dose chromium (Cr) supplementation in early postpartum dairy cows during the summer months. Multiparous, early postpartum cows (20.95 ± 0.21 DIM, 658.29 ± 13.61 kg) were assigned to one of two treatment groups: 1) normal TMR (Con; n=10) and 2) normal TMR + Cr propionate supplementation (CrPro; 12 mg/h/d Cr; n=12). Body weight (BW), milk yield, and feed intake were measured each day of the experiment. Ambient temperature and humidity were monitored, and the temperature-humidity index (THI) was calculated for the duration of the study as an indicator of the severity of the heat stress experienced by the cows. Transrectal ultrasonography was performed every three days to assess ovarian follicular and luteal dynamics. Respiration rates (RR), rectal temperatures (RT), and blood glucose were recorded concurrently with ovarian ultrasonography. Plasma was collected and used for analysis of progesterone concentrations. Every six days in conjunction with ultrasonography, endometrial cytology samples were collected via cytobrush from each cow to determine the incidences of subclinical endometritis (SCE), as determined by polymorphonuclear leukocyte (PMNL) %. There were no treatment-based differences in RR, RT, blood glucose, feed intake, milk yield, or BW. However, the supplementation strategy did improve reproductive parameters. Within the Con group, there was an increase in PMNL % betwe