The objective was to examine the prevalence of extended-spectrum β-lactam (ESBL) resistance among Shiga toxigenic Escherichia coli (STEC) isolated from raw milk. The findings from disc diffusion analysis and polymerase chain reaction revealed a high occurrence of ESBL resistance, specifically to penicillins, cephalosporins, and carbapenems, in isolated STEC strains. Additionally, a distinct sequence type of STEC was also identified in milk through comparative analysis.

This research paper aimed to demonstrate that mammary secretions provided by sheep farmers across Scotland from cases of clinical mastitis are free from environmental contamination, as well as to provide information on the major bacterial causes of disease and levels of antimicrobial resistance. Mastitis represents one of most significant diseases of small ruminant production worldwide. Staphylococcus aureus, Mannheimia haemolytica, Streptococcus uberis and coagulase-negative Staphylococcal species are common pathogens isolated from cases of sheep mastitis. Sampling kits supplied to 23 farms provided 33 samples for bacteriology, antimicrobial susceptibility testing and genetic analysis. Of the bacterial isolates identified, 60% were S. aureus, 23% M. haemolytica and 7% coagulase-negative staphylococci. Low levels of antimicrobial resistance were identified in the S. aureus isolates which provided novel multi-locus sequence types. In conclusion, this proof-of-concept survey demonstrated that mammary secretions free from environmental contamination may be provided by sheep farmers. It also provided data on the prevalence of antimicrobial resistance associated with clinical mastitis in sheep and will inform on the scale required for larger surveys aiming to improve current strategies for mastitis control in sheep flocks across the UK.

This study aimed to estimate live body weight from body measurements for Holstein × Zebu dairy cows (n = 156) reared under conditions of humid tropics in Mexico using multivariate adaptive regression splines algorithm (MARS) with several train-test proportions. The body measurements included withers height, rump height, hip width, heart girth, body length and diagonal body length. The data were divided into 65:35, 70:30 and 80:20 split data for training and testing sets, respectively. The MARS algorithm was used to construct a prediction model, which predicted the body weight from the body measurements of the test dataset. The results emphasized that the MARS algorithm had an explanation rate for 80:20 train and test set of 0.836 and 0.711, respectively, with minimum Akaike information criterion values. This indicates that it is a reliable way of predicting body weight from body measurements. The results suggest that body weight prediction can be performed with the MARS algorithm in a reliable way, therefore, this algorithm may be a useful tool for animal breeders and researchers in the development of feeding and selection-aimed approaches.

This research communication screened and identified differentiated expressed genes in bovine mammary epithelial cells (BMECs) upon prolactin (PRL) stimulation. PRL of 5 μg/ml increased β-casein synthesis in BMECs with milk protein synthesis capacity. RNA sequencing (RNA-seq) was used to screen differentially expressed genes (DEGs). A total of 375 DEGs (165 up-regulated and 210 down-regulated) were identified between PRL-stimulated group and the control group. Gene ontology enrichment analysis showed that the up-regulated genes were primarily associated with cell functions, metabolic processes, and biological regulatory processes. Pathway enrichment analysis showed that the up-regulated genes were mainly enriched in JAK-STAT, Rap1, Ras and Notch signaling pathways, which are widely involved in cell proliferation, differentiation and milk component synthesis. This study provides an initial understanding of the changes in gene expression in BMECs with PRL-stimulation, as determined by RNA-seq transcriptomic analysis, thereby enhancing our knowledge of the molecular regulation of lactation metabolism.

One of the major challenges in lameness management is prompt detection, especially before visible gait disturbance. This scoping review describes the potential biomarkers for lameness in dairy cows reported in the literature, their relevance in lameness diagnosis, identifying cows at risk of developing claw lesions and monitoring recovery after treatment. Using specific keywords, a comprehensive literature search was performed in three databases: PubMed, Google Scholar and ScienceDirect to retrieve relevant articles published between 2010 and 2022. A total of 31 articles fulfilling the inclusion criteria were analysed. The categories of potential markers for lameness reported in the literature included acute phase proteins (APPs), nociceptive neuropeptides, stress hormones, proteomes, inflammatory cytokines and metabolites in serum, urine and milk. Cortisol, APPs (serum amyloid A and haptoglobin) and serum, urinary and milk metabolites were the most studied biomarkers for lameness in dairy cows. While APPs, nociceptive neuropeptides and blood cortisol analyses assisted in elucidating the pain and stress experienced by lame cows during diagnosis and after treatment, evidence-based data are lacking to support their use in identifying susceptible animals. Meanwhile, metabolomic techniques revealed promising results in assessing metabolic alterations occurring before, during and after lameness onset. Several metabolites in serum, urinary and milk were reported that could be used to identify susceptible cows even before the onset of clinical signs. Nevertheless, further research is required employing metabolomic techniques to advance our knowledge of claw horn lesions and the discovery of novel biomarkers for identifying susceptible cows. The applicability of these biomarkers is challenging, particularly in the field, as they often require invasive procedures.

Signal transducers and activators of transcription (STAT) genes are involved in signal mediation of various hormones and cytokines. STAT1 located on chromosome number 2 is involved in mammary gland development and is associated with milk composition traits in bovines. This study aimed to find any relationship and impact of STAT1/BspHI gene with milk fat and protein yields in a herd of Holstein Friesian (HF) crossbred cattle of sub-tropical climate of Northern India. Milk composition data of 535 adult HF crossbred cows for a period of 12 years was collected from the records maintained at Livestock Farm, Guru Angad Dev Veterinary and Animal Sciences University. First lactation data of 222 animals was chosen for further analysis. After data correction for non-genetic factors (season of calving, period of calving, interaction effect of season and period of calving and age at first calving) these animals were categorised into two groups based on corrected high and low milk fat and protein yields. Forty animals were then selected for blood collection and further laboratory analysis. Amplified using PCR-RFLP technique, the 314 bp STAT1 gene was digested using BspHI restriction enzyme. C-T polymorphism at nucleotide position 201 and 260 of the STAT1 amplicon was observed. At 201, for genotype AA and Aa, the genotypic frequencies were 0.80 and 0.20%. At 260, for genotype BB and Bb, the genotypic frequencies were 0.25 and 0.75%. Least square analysis showed a significant association of all genotypes with milk fat and protein yields. Hence, STAT1 can be used as a potential candidate gene to aid in better animal selection in breeding programmes.

Integrons are important genetic elements that allow easy acquisition and dissemination of antimicrobial resistance genes. Studies reporting occurrence of integrons in Staphylococcus aureus (S. aureus) isolated from bovine mastitis in large dairy farms across China are scarce. The aim of this study was to investigate the occurrence of class 1 integrons (intI1), antimicrobial resistance (AMR) and associated genes in S. aureus isolated from bovine mastitis and their associations. Minimum inhibitory concentrations (MICs) were determined to evaluate the AMR phenotypes, whereas PCR was carried out to assess the occurrence of AMR genes and intI1. In addition, index cluster analysis was used to estimate associations between AMR phenotype, genotype and intI1 in 103 isolates. Overall, 83% of S. aureus were intI1-positive and 5 types of gene cassettes were detected. Susceptibility against single antimicrobial agents ranged from 0% (erythromycin), 12% (ampicillin) and 16% (penicillin G) to 96% (gentamicin). Most isolates (64%) were intermediate-resistant against erythromycin, whereas resistance against ceftriaxone (22%), clindamycin (4%), cefotaxime (2%), tetracycline (1%) and ciprofloxacin (1%) were relatively uncommon. The predominant resistant gene was blaZ gene (n = 88, 85%) followed by tetD gene (n = 85, 83%). With an estimated prevalence of 12% of the mecA gene, methicillin-resistant S. aureus isolates had higher MIC50 and MIC90 for majority of antimicrobials than methicillin-susceptible S. aureus isolates. Presence of the ermC gene was associated with erythromycin resistance. Ampicillin, erythromycin and penicillin G resistance were associated with intI1. The data presented in our study indicated that class 1 integron-mediated resistance possibly plays an important role in dissemination of AMR in S. aureus isolated from bovine mastitis.

This research paper describes a validation study evaluating the ability of IceTag accelerometers (Peacock Technology, UK) to detect play behaviour in weaned dairy calves. Play behaviour is commonly observed in young animals and is regarded as an indicator of positive welfare states. Eight Holstein Friesian calves aged three to five months old were monitored using leg-mounted accelerometers for 48 h. Data generated by accelerometers to quantify calf activity included step count, lying times and a proprietary measure of overall activity termed ‘motion index’ (MI). Calf behaviour was filmed continuously over the same 48-h period using closed circuit television cameras and analysed using one-zero sampling to identify the presence (1) or absence (0) of play within each 15-min time period. A positive correlation between MI and visually recorded play was found. Visual observations were compared with accelerometer-generated data and analysed using 2 × 2 contingency tables and classification and regression tree analysis. A MI value of ≥69 was established as the optimum threshold to detect play behaviour (sensitivity = 94.4%; specificity = 93.6%; balanced accuracy = 94.0%). The results of this study suggest that accelerometer-generated MI data have the potential to detect play behaviour in weaned dairy calves in a more time efficient manner than traditional visual observations.

This research communication reports the effects of a compound enzyme preparation consisting of fibrolytic (cellulase 3500 CU/g, xylanase 2000 XU/g, β-glucanase 17 500 GU/g) and amylolytic (amylase 37 000 AU/g) enzymes on nutrient intake, rumen fermentation, serum parameters and production performance in primiparous early-lactation (47 ± 2 d) dairy cows. Twenty Holstein–Friesian cows in similar body condition scores were randomly divided into control (CON, n = 10) and experimental (EXP, n = 10) groups in a completely randomized single-factor design. CON was fed a basal total mixed ration diet and EXP was dietary supplemented with compound enzyme preparation at 70 g/cow/d. The experiment lasted 4 weeks, with 3 weeks for adaptation and then 1 week for measurement. Enzyme supplementation significantly increased diet non-fibrous carbohydrates (NFC) content as well as dry matter intake (DMI) and NFC intake (P < 0.05). EXP had increased ruminal butyrate and isobutyrate percentages (P < 0.01) but decreased propionate and valerate percentages (P < 0.05), as well as increased serum alkaline phosphatase activity and albumin concentration (P ≤ 0.01). Additionally, EXP had increased milk yield (0.97 kg/d), 4% fat corrected milk yield and energy corrected milk yield, as well as milk fat and protein yield (P < 0.01). In conclusion, dietary supplementation with a fibrolytic and amylolytic compound enzyme preparation increased diet NFC content, DMI and NFC intake, affected rumen fermentation by increasing butyrate proportion at the expense of propionate, and enhanced milk performance in primiparous early-lactation dairy cows.

Minerals are supplemented routinely to dairy cows during the dry period to prevent metabolic issues postpartum. However, limited information exists on the impacts of mineral supplementation on colostrum carotenoids. This study aimed to determine the effects of prepartum supplementation with three micro-nutrients; inorganic selenium (INORG), organic selenium (ORG) or rumen-protected choline (RPC) on the carotenoid content of bovine colostrum and transition milk (TM) from pasture-based dairy cows. A total of 57 (12 primiparous and 45 multiparous) Holstein-Friesian (HF) and HF × Jersey (JEX) cows were supplemented daily for 49 ± 12.9 d before calving. Colostrum samples were collected from all cows immediately postpartum and TM one to five (TM1–TM5) were collected from a sub-set of 15 cows (five per treatment group) at each consecutive milking postpartum. Carotenoid concentration was determined using ultra-high performance liquid chromatography – diode array detection (UHPLC-DAD). With the use of transmittance, the colour index and colour parameters a*, b* and L* were used to determine colour variations over this period. Prepartum supplementation did not have a significant effect on colostrum β-carotene concentration or colour. Positive correlations between β-carotene and colour parameter b* (R2 = 0.671; P < 0.001) and β-carotene and colour index (R2 = 0.560; P < 0.001) were observed. Concentrations of β-carotene were highest in colostrum (1.34 μg/g) and decreased significantly with each milking postpartum (TM5 0.31 μg/g). Breed had a significant effect on colostrum colour with JEX animals producing a greater b* colostrum than HF animals (P = 0.030). Primiparous animals produced colostrum with the weakest colour compared to second or ≥third parity animals (P = 0.042). Despite statistical increases in the b* parameter in colostrum from JEX cows and multiparous cows, β-carotene concentrations did not significantly increase suggesting that other factors may influence colostrum colour. The b* parameter may be used as an indicator for estimating carotenoid concentrations in colostrum and TM, particularly when assessed via transmittance spectroscopy.

The work reported in the Research Communication investigated in vitro rumen gas kinetics and fermentation profile as well as in vivo performance of lactating ewes fed corn silage (CS), sunflower silage (SFS) and their 50 : 50 mixture (CS-SFS). For the in vivo experiment, nine early-lactation Suffolk × Texel ewes were grouped in a replicated 3 × 3 Latin square design of three 21-d periods. Treatments were based on ad libitum CS, SFS, and CS-SFS supplemented with concentrate at 48 g/kg LW0.75. In vitro results showed that the CS had the highest dry matter degraded substrate and microbial crude protein production followed by CS-SFS. The in vivo data showed that animals fed on CS had higher digestibility of dry matter and organic matter than CS-SFS, while SFS were intermediate. Nitrogen (N) intake, fecal N excretion, and urine N excretion were similar between groups, however, milk N excretion was lower in SFS than CS. Milk yield was higher for CS and CS-SFS than SFS group, however, SFS-fed ewes had higher milk fat content than either CS or CS-SFS (all differences reported here were significant, P < 0.05 or better). Overall, CS-SFS could be used as dietary roughage for dairy ewes without deleterious effects on nutrient intake, N-balance and milk yield whilst potentially offering a more sustainable alternative to CS.

This research paper addresses the hypothesis that substituting soybean meal with locally produced yeast protein from Cyberlindnera jadinii in barley-based concentrates for Norwegian Red (NR) dairy cows does not have adverse effects on milk fatty acid (FA) composition, rumen microbiota and sensory quality of milk. As soybeans also represent valuable protein sources for human consumption, alternative protein sources need to be investigated for animal feed. A total of 48 NR dairy cows were allocated into three feeding treatments, with the same basal diet of grass silage, but different concentrates. The concentrates were all based on barley, but 7% of the barley in the barley-concentrate (BAR; negative control) was replaced by either soybean meal (SBM; conventional control) or yeast microbial protein (YEA). The experiment lasted for a total of 10 weeks, including 2 weeks of adaptation with the soybean meal concentrate. Analysis of the feed revealed some differences in the FA composition of the YEA concentrate compared to the SBM and BAR concentrates. In milk, only two FAs (C17:1n-8cis9 and an unidentified isomer of C18:3) were significantly different between the YEA- and SBM-group, while six FAs differed between the BAR- and SBM-group. However, the amount of these FAs was low compared to the entire FA profile (<0.7 g/100 g). The experimental diets did not affect rumen microbiota nor the milk sensory quality. This study shows that C. jadinii can replace soybean meal as a protein source in concentrates (7% inclusion) for NR dairy cows fed a diet composed of grass silage and concentrates without any effects on rumen microbiota, and without compromising the FA composition or sensory quality of milk.

This research paper proposes a simple image processing technique for automatic lameness detection in dairy cows under farm conditions. Seventy-five cows were selected from a dairy farm and visually assessed for a reference/real lameness score (RLS) as they left the milking parlor, while simultaneously being video-captured. The method employed a designated walking path and video recordings processed through image analysis to derive a new computerized automatic lameness score (ALDS) based on calculated factors from back arch posture. The proposed automatic lameness detection system was calibrated using 12 cows, and the remaining 63 were used to evaluate the diagnostic characteristics of the ALDS. The agreement and correlation between ALDS and RLS were investigated. ALDS demonstrated high diagnostic accuracy with 100% sensitivity and specificity and was found to be 100% accurate with a perfect agreement (ρc = 1) and strong correlation (r = 1, P < 0.001) for lameness detection in binary scores (lame/non-lame). Moreover, the ALDS had a strong agreement (ρc = 0.885) and was highly correlated (r = 0.840; 0.796–1.000 95% confidence interval, P < 0.001) with RLS in ordinal scores (lameness severity; LS1 to LS5). Our findings suggest that the proposed method has the potential to compete with vision-based lameness detection methods in dairy cows in farm conditions.

This study investigates a novel early pregnancy marker in water buffaloes, focusing on RSAD2 mRNA expression, known to be upregulated by interferon-tau (IFNT) during pregnancy. While RSAD2 is primarily recognized for its antiviral effect, we hypothesized its role as a conceptus-induced component in regulating pregnancy in buffaloes. Given its differential expression compared to other IFNT-induced genes in cows, RSAD2 may serve as a biomarker for early pregnancy detection in buffaloes. RNA, cDNA, and plasma samples were obtained from archived samples collected before insemination (d0) and at d20, d25 and d40 after insemination. Twelve RNA samples, having optimal optical density and concentration, from six pregnant and six non-pregnant buffaloes were selected. The cDNA was analyzed to measure the abundance of RSAD2 mRNA using real-time quantitative PCR (RT-qPCR) and plasma for protein expression analysis using Western blot. The RT-qPCR analysis showed a transcript of RSAD2 increased significantly by 7-fold and 6-fold on d20 and d25, compared to both d0 and d40 in the pregnant group only. At d20, the sensitivity of RSAD2 was 100% and the specificity was 83.3%, and at d25-d both the sensitivity and specificity was 100%, indicating low incidences of misdiagnosing early pregnancy in buffaloes. In the non-pregnant group, RSAD2 expression remained low and did not change after insemination. Western blot analysis revealed an immunoreactive RSAD2 protein band. Densitometry analysis of the RSAD2-specific protein band, based on gray mean value, showed significantly increased expression of RSAD2 at d25 compared to d0 in the pregnant group. In conclusion, these results indicated that RSAD2 expressions at both the mRNA and protein levels show promising potential for detecting pregnancy at d25 post-insemination.

This Research Communication introduces a novel enzymatic-fluorometric analytical procedure for glycerol and glycerol 3-phosphate in milk. Milk from thirty-seven goats was analysed during 9 consecutive days during which a two-day feed restriction was introduced. Fractional milk triacylglyceride and free glycerol increased significantly while glycerol 3-phosphate reacted more moderately. The energy status of the mammary cell is discussed.

α-Lactalbumin (α-LA) and β-lactoglobulin (β-LG) are major whey proteins in bovine milk. We studied the effects of these molecules on the intestinal cell response by comparing the native form with the denatured form containing oligomers obtained by treatment with 2,2,2-trifluoroethanol (TFE). We previously reported that proteins in native and TFE-treated forms exhibited cell growth stimulation and cytotoxicity, respectively, in undifferentiated rat crypt IEC-6 and human colon Caco-2 cells. However, neither whey protein showed cytotoxicity even in the TFE-treated form in differentiated Caco-2 cells. Only undifferentiated immature intestinal cells can distinguish between these native and denatured proteins. Moreover, α-LA and β-LG exhibited different oligomer formation characteristics during the TFE treatment. In the present study, we compared the effects of native and TFE-treated whey proteins on IEC-6 cells in more detail. The native forms of both whey proteins exhibited cell proliferative effects in a concentration-dependent manner. For the TFE-treated forms, α-LA showed rapid and potent cytotoxicity, whereas β-LG altered cell responses depending on its concentration and exposure time; lower concentration/shorter exposure and higher concentration/longer exposure induced cell growth stimulation and cytotoxicity, respectively. Pre-treatment of the cell membrane with cholesterol suppressed the effects on the cell response only in TFE-treated β-LG (TFE-β-LG). In a preliminary examination using inhibitors of signal transduction, TFE-treated α-LA acted on the intrinsic apoptosis pathway via Bcl-2-associated X and p53, whereas the action of TFE-LG did not require this pathway. Tyrosine phosphorylation is necessary for the cell proliferation effect of both native whey proteins; however, native α-LA, but not native β-LG, also required activation of the pathway with selective epidermal growth factor receptor tyrosine kinase and Janus kinase 2/3. In summary, the two major bovine milk whey proteins induced similar yet discrete responses in undifferentiated intestinal cells. Even when oligomers are formed, β-LG may be much less hazardous to immature intestinal cells than α-LA.

This research article describes an investigation into the udder health, bacterial isolation and antimicrobial sensitivity of three staphylococcal species isolated from the milk of non-dairy goats, suckling their kids, on two smallholder farms in the Hong Kong Special Administrative Region. Udder lesions were visually noted in 21 of 34 goats and two goats had palpable abnormalities. Collected milk samples grew a total of 11 bacterial organisms and the most frequently isolated organism was Staphylococcus chromogenes. Selected isolates of S. aureus, caprae and simulans from both farms were tested by antimicrobial sensitivity testing for 23 antimicrobials and all isolates showed antimicrobial resistance to doxycycline and tetracycline. Less common resistance was shown to ampicillin, chloramphenicol, penicillin and rifampicin. This preliminary study confirms the presence of udder lesions and mastitis bacteria in non-dairy goats in Hong Kong, along with the first information on the antimicrobial profile of three common Staphylococcus species bacteria affecting goats.

The geometry of milk liners may affect milking performance and cow comfort as the milk liner is the only part of the milking machine that comes into contact with the teat. To determine the effect of alternative shape of milk liners we compared square (SQR) vs. the conventional round (RND) teat cup liner on milking performance and comfort of dairy cows. Treatment milk liners were randomly allocated to clusters within each side of the 12 a side double up-herringbone dairy shed in a complete randomised block design over two periods. Milking performance data from a total of 10 065 (late stage of lactation and once-a-day milking frequency, LATE) and 18 048 (early stage of lactation and twice-a-day milking frequency, EARLY) milking events were automatically recorded by a DeLaval milk meter, and separately analysed for LATE and EARLY, respectively. In EARLY, cow comfort behaviour was also recorded during afternoon milking sessions. Across the two study periods, average milk flow rate, milk flow rate during 0–15, 15–30 and 30–60 s after cluster attachment, and milk flow rate at cluster take-off were higher in SQR compared to RND treatment. Proportion of time in a milking session with low milk flow rate and duration of milking session were less in SQR compared to RND treatment. However, effect of geometry of milk liner on peak milk flow rate was inconsistent across the two-study periods. Peak milk flow rate was higher (P < 0.001) in SQR than RND in LATE, but higher (P < 0.001) in RND than SQR in EARLY. Stomping and kicking behaviours of cows were similar between treatments. Results of this study suggest that square milk liners potentially improve milking performance, without adverse effect on cow comfort compared to conventional round liners. Long-term, multi-site studies are required to confirm potential teat-end health benefits associated with square milk liners and further verify these results.