The study presented in this Research Communication aimed to investigate the relationship between physiological responses, body surface temperature and shade-seeking behaviour in Nili Ravi dairy buffaloes during summer months. We enrolled 60 buffaloes, and each animal was observed for three consecutive days starting before sunrise until they moved towards the shade structures. A repeated measures ANOVA was employed to assess the changes in physiological parameters and body surface temperature between the early morning and the occurrence of shade-seeking behaviour. The average temperature humidity index and heat load index during the behavioural monitoring period (0400 to 1200 h) were 81.3 ± 6.5 and 92.9 ± 17, respectively (mean ± sd). There was no significant difference in core body temperature between sunrise and the time of shade-seeking event. However, the buffaloes had a slightly higher respiration rate at the time of shade-seeking (19.2 vs. 22.4 breaths/min). In addition, body surface temperature, measured at the flank region, shoulder, base of the ear and forehead was significantly higher at the occurrence of shade-seeking behaviour compared to the early morning. On average, the buffaloes sought shade when the surface temperature was 2°C higher than the temperature recorded before sunrise. Overall, the current findings suggest that body surface temperature, rather than core body temperature was strongly associated with shade-seeking behaviour in dairy buffaloes. These findings could be useful in developing strategies to mitigate the effects of heat stress in dairy buffalo herds and thereby improve animal welfare.

Milk fat synthesis is tightly regulated by hormones and growth factors. Leptin is a versatile peptide hormone that exerts pleiotropic effects on metabolic pathways. In this study, we evaluated the expression and function of leptin and its long form receptor OB-Rb in dairy cow mammary tissues from different physiological stages and in cultured mammary epithelial cells. The results showed that the expression of leptin and OB-Rb were significantly higher in the mammary tissues of lactating cows as compared with dry cows, suggesting that they are related to milk component synthesis. In cultured dairy cow mammary epithelial cells, leptin treatment significantly increased OB-Rb expression and intracellular triacylglycerol content. Transcriptome analysis identified the difference in gene expression between leptin treated cells and control cells, and 317 differentially expressed genes were identified. Gene ontology and pathway mapping showed that lipid metabolism-related gene expression increased and signal transduction pathway-related genes were the most significantly enriched. Mechanistic studies showed that leptin stimulation enhanced sterol regulatory element-binding protein 1 expression via activating the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway, which in turn up-regulated the expression of genes related to milk fat synthesis. Moreover, we found that fatty acid synthesis precursors, acetate and β-hydroxybutyrate, could positively regulate the expression of leptin and OB-Rb in bovine mammary epithelial cells, thereby potentially increasing milk fat synthesis. Our study provided novel evidence in the regulation of leptin on milk fat production in mammary glands of dairy cows, as well as experimental basis for artificial regulation of milk fat

Rapid diagnostic tests that differentiate between Gram positive, Gram negative and the absence of aerobic bacteria in milk samples from dairy cows with clinical mastitis can support antimicrobial treatment decisions and contribute to a more prudent use of antimicrobials in the dairy industry. The objective of this study was to evaluate the test characteristics of the novel rapid BACT mastitis test in discriminating causes of clinical mastitis under laboratory conditions. Test outcomes of 155 milk samples from clinical mastitis cases were incubated for 14–16 h in the BACT test and compared to results of bacteriological culture. The accuracy for detection of bacterial growth and Gram positive growth was 91 and 89%, respectively. The BACT test could provide an accurate and relatively fast decision tool for farmers to aid in antimicrobial treatment decisions in cases of clinical mastitis.

This research communication addresses the hypothesis that double premilking teat disinfection (DD) is more effective in reducing soiling and bacterial count on the cows' teat skin and milkers' gloves than conventional disinfection (CONV). The design was a 3 × 3 Latin square (three groups of cows and three treatments) with conventional teat disinfection (CONV, lactic acid application after forestripping), double teat disinfection using the same disinfectant (DD1D, lactic acid application before and after forestripping), and double teat disinfection using two different disinfectants (DD2D, application of lactic acid before and chlorine-based disinfectant after forestripping). All groups were assigned for six days for each treatment, and the evaluations and samples were collected on the last day, before and after treatment. We evaluated the teat cleanliness score (TCS), count of Gram-negative bacteria (coliforms and noncoliforms), Staphylococcus spp., Streptococcus spp., and total bacterial count (TBC) on the cows' teats and TBC on the milkers' gloves. TCS after premilking was lower in DD than CONV treatment. The reduction of Staphylococcus spp. count was greater in the DD treatment and tended to be higher in the DD2D. The TBC reduction on the cows' teats was greater in the DD treatments. The TBC on the milkers' gloves was lower for DD before and after premilking. In conclusion, DD can be an alternative for reducing some bacterial populations on cow teats and preventing the transmission of microorganisms between cows via the milkers' hands.

We aimed to determine the efficacy of different post-milking teat dips in the prevention of intramammary infection and teat condition scores in common crossbred cows (Holstein Frisian × Tharparkar) found in Indian sub-tropical conditions. Eighty healthy crossbred cows were selected and randomly divided into four groups: untreated control, 1% w/v iodine, 5% v/v lactic acid and finally essential oil mix (eucalyptus, lavender, peppermint, and tea tree oils). Samples were collected quarter-wise (n = 308). Sampling as well as teat scoring was done simultaneously. 1st sample was collected before starting teat dipping, followed by 15th day in milk (DIM), 45th DIM and 90th DIM, respectively. The study found that post-milking teat dipping significantly reduced the mean California mastitis test score, somatic cell count and electrical conductivity of the milk in the treatment groups compared to the control group, and also improved milk yield in the treatment groups. There were no differences between the individual treatments. The study also found a significant reduction in teat end condition and teat skin condition after 90 d of post-milking teat dipping.

We investigated the antimicrobial components in cow milk at dry off and postpartum and their contribution in preventing new high SCC at quarter level. Milk samples from 72 quarters of 19 lactating cows were collected at last milking before dry off and at 7 d after parturition. Milk yield of each cow was recorded and SCC, IgG, IgA, lactoferrin, lingual antimicrobial peptide (LAP), and S100A7 concentrations in each quarter milk sample were measured. The postpartum milk yield was significantly higher than that at dry off. The IgG, IgA and lactoferrin concentrations in milk at dry off were significantly higher than those at postpartum, whereas the LAP concentration was lower. Quarters with SCC < 300 000 cells/ml at both dry off and postpartum were classified as persistent low SCC (PL) whereas those that rose above that same threshold postpartum were classified as new high SCC (NH). At dry off, IgG and LAP concentrations in milk were significantly higher in PL than in NH. These results suggest that high LAP concentrations during the dry period may contribute toward the prevention of new high SCC.

Milk is a fundamental food matrix that is widely consumed. Milk fat is important for producing dairy products such as butter, cream, cheese and whole milk powder. Aside from flavour, it has been linked to human health and its chemistry can be modulated by various means towards a more healthy fatty acid profile. Industry and stakeholders have different interests in milk fat, based on specific policies which reflect the type of research and funding initiatives currently performed in different countries. This position paper summarizes the current state-of-the-art with regards to milk fat research and industry as well as stakeholder initiatives, and then highlights new developments based on information gathered from North America (United States and Mexico), Europe (United Kingdom, Spain, Italy, and Finland), Africa (Egypt), Asia (China and Bangladesh) and Oceania (New Zealand). South America is an important contributor to the dairy industry but will not be considered here and thus this paper must be considered cross-continental rather than global. This manuscript intends to show a wide ‘picture’ of milk fat from different angles in different parts of the globe.

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.

In free-range (extensive) dairy farming the wealth and type of consumed vegetation positively affects milk characteristics such as flavour. As free-range feeding is included as a requirement in the specifications of certain protected designation of origin cheeses, there is a need to develop methodology to identify different animal feeding regimes. This study evaluated goat milk based on two feeding regimes, namely free-range and intensive (controlled diet fed exclusively at the farm). Conventional mid-infrared spectroscopy (4000–400 cm−1) using Fourier transformed infrared technology was assessed for the discrimination of 65 milk samples obtained during spring time from the same dairy farm and breed of animals, which could be categorized as intensive and free-range feeding regimes. Chemometric analysis, whereby a supervised method of orthogonal partial least-square-discriminant analysis was applied, was shown to be essential for interpreting the spectroscopic data. The produced model returned distinct clusters of the two milk types, intensive and free-range with 95.4% correct classification accuracy.

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.

The study was carried out in dairy cows to elucidate whether treatment of clinical mastitis quarters with Spectramast® LC (ceftiofur hydrochloride, 125 mg, Zoetis) created a reason for discarding milk from adjacent untreated healthy quarters. The antibiotic was infused once daily in the affected mammary quarter for four days. Forty-nine cows were evaluated after diagnosis of clinical mastitis in three or fewer udder quarters. In all cases, quarters that did not receive treatment had milk samples collected one day after the end of treatment. All milk samples from untreated quarters were below the maximum permissible limit for the presence of antibiotic residues after analysis with the BetaStar S Combo test. Pharmacokinetic and pharmacodynamic characteristics may explain this finding. We conclude that it is feasible to use milk from untreated quarters of animals that have been treated with Spectramast® LC. We also reiterate the need to carry out tests with other pharmacological bases, and that the results found in this experiment cannot be extrapolated to other drugs.

Dairy cattle have considerable importance in the development of the Brazilian economy, being directly linked to economic and social progress. In the first half of 2020, 12.1 billion liters of milk were produced in Brazil and in 2019, there was a new record of 25.01 billion liters produced (IBGE, 2020). This production comes from a wide variety of production systems, coming from smallholder farmers as well as from large companies that use the latest technologies available on the market. Dairy production is a complex activity. For one to obtain economical success, several aspects must be monitored. Maintaining the health of animals is a top priority, and the literature suggests that various diseases are a common challenge for dairy producers. Mastitis is the main disease that affects dairy cows, responsible for considerable economic loss and significant zootechnical and productive challenges (Ruegg, 2017). It is considered the second leading cause of cow culling in dairy herds, behind reproductive problems. Mastitis is characterized by infection of the mammary gland and may or may not occur with inflammation, generating changes in the mammary tissue and properties of the milk. It is classifield into clinical or subclinical mastitis, according to presence or absence of clinical signs, and into contagious or environmental based on the causative agent (Correa et al., 2001).

The aim of this research was to investigate the ability of an in vitro simulated gastrointestinal digestion (SGID) to generate peptides from bovine lactoferrin (LF) that possess antibacterial activity. Escherichia coli was examined as the target pathogen due to its prevalence in foods and the well-documented antibacterial effect of both LF and LF peptides against this organism. Results showed that in-vitro digested LF, specifically gastric LF digesta, exhibited significant antibacterial activity at low concentrations against E. coli compared to its undigested counterpart. Additionally, the highest antibacterial activity in the gastric digesta was associated with a relatively high molecular weight fraction of >30 kDa obtained within the first 30 min of the SGID. This demonstrates that the digestive process can result in the generation of antibacterial LF peptides and contribute to improving the antimicrobial properties of LF exhibited in its undigested state, making it a suitable dairy food additive to potentially provide protection against bacterial pathogens within the gastrointestinal system.

We evaluated the effect of including 0, 2, 5, 10, 20, 40 and 100% of individual milk from cows at extended lactation (more than 315 d in milk) on milk ethanol stability (MES), pH, acidity and ionic calcium (iCa) of the bulk tank milk. The study was carried out on commercial dairy farms in Brazil using milk samples of individual cows, bulk tank and their mixtures. Samples of individual cows were classified as low (≤74%), intermediate (76–78%) and high (≥80%) stability classes based on MES. Data were submitted to Anova, multiple linear regression analysis and logistic regression. Low, intermediate and high stability milk had values of 108, 89 and 79 mg/dl for iCa, and 21, 23 and 20 for acidity, respectively, but similar values for pH and DIM. MES increased linearly with pH, while it decreased linearly with iCa. When individual milks presented higher MES than bulk tank milk, MES and pH increased linearly with individual milk inclusion and DIM, while iCa decreased with individual milk inclusion. When individual milks presented lower MES than bulk tank milk, MES decreased, while iCa increased linearly with individual milk inclusion. Inclusion of milk with higher MES than the bulk tank decreased the odds of low stability, while inclusion of individual milk with lower MES than bulk tank increased it. At extended lactation, 73% of cows produced milk with acceptable (intermediate or better) MES, and iCa was the only functional variable related to MES. Effects of the mixture of individual milks into bulk tank milk functional traits depend on whether individual cows present values higher or lower than bulk tank.

The aim of this study was to compare the effects of feeding pasteurized waste milk or saleable milk to calves on weight, health and emergence of antimicrobial resistance in Escherichia coli strains isolated from those calves. An experimental study under field conditions on a commercial pasture-based Argentinian dairy farm was carried out. Forty Holstein calves were assigned randomly to either pasteurized waste milk (PWM) or non-pasteurized saleable milk (SM). The antimicrobial agents (AM) used on the farm, both to treat or prevent diseases, were recorded. The passive immunity level, calf live weight, AM presence in milk, clinical examination of calves, and E. coli isolation and identification, were performed. A total of 258 E. coli strains were isolated from fecal samples (132 isolates from SM calves and 126 from PWM calves at six sampling times). All E. coli isolated were used to perform AM susceptibility tests (disc diffusion and agar dilution). No differences were observed between groups in health parameters, average daily gain or prevalence of resistant E. coli strains to any AM evaluated throughout the study. Peaks of trimethoprim, sulfamethoxazole and enrofloxacin minimum inhibitory concentration (MIC) were observed at 30 d in E. coli from both groups of calves, whilst additional peaks to tetracyclin and ampicillin were observed only in SM calves. All MIC apart from gentamicin decreased at 75 and 90 d of age (during the weaning period). Gentamicin MIC behaved differently, having no peaks and increasing at 90 d only in PWM group. In conclusion, we found no evidence that emergence of antibiotic resistance is related to the consumption of pasteurized waste milk.

In this research communication we investigate the prevalence and antimicrobial susceptibility of S. aureus harboring virulent genes responsible for mastitis in cattle of Punjab, Pakistan. A total of 690 milk samples were collected from commercial dairy farms for analysis of the prevalence of subclinical and clinical mastitis and isolation of S. aureus. Virulence ability and methicillin resistance in S. aureus (MRSA) was determined by targeting the pvl (the gene for Panton–Valentine leukocidin) and mecA genes, respectively. A total of 175 S. aureus isolates exhibiting prevalence of pvl gene (6.28%) and mecA gene (22.28%) were determined. Antimicrobial susceptibility testing of pvl positive and negative MRSA against different classes of antibiotics revealed 100% resistance against β-lactams while 100% sensitivity towards tylosin and linezolid.

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.

In this research paper we introduce and validate an enhanced method for the detection of sodium benzoate and potassium sorbate in milk. Sodium benzoate and potassium sorbate are widely employed as preservatives in the food industry; however, their use to restrict microbial growth in milk is prohibited. Our novel method achieved performance indicators in accordance with the criteria outlined by the International Conference on Harmonization. The extraction process involved sample dilution in acetonitrile (1:1 v/v), followed by subsequent centrifugation, filtration and injection into a high-performance liquid chromatography system with a photodiode array detector. The detection and quantification limits for sodium benzoate were determined to be 0.204 and 0.618 mg/l, respectively, while for potassium sorbate, these values were 0.108 and 0.328 mg/l, respectively. The accuracy ranged from 92.67 to 99.53%, with pH 4.0 selected as the optimal condition to ensure adequate resolution of the preservatives. The proposed method stands out due to its simplicity and speed, using a single reagent in modest quantities during sample preparation. This approach reduces toxicity and minimizes the production of pollutants during disposal. Furthermore, the novel method requires less raw material and energy consumption, aligning with the principles of green chemistry. Its lower quantitation limits render it more sensitive when compared to the official analysis. The preparation, separation, and simultaneous detection of these preservatives in a short period of time make this method suitable for integration into industrial workflows.

This study aimed to elucidate the effects of various nutritional supplements on the physical, structural and sensory attributes of low-fat yogurt derived from camel milk, with the longer-term objective of enhancing its appeal and suitability for elderly consumers. Fresh camel milk was obtained from an Australian farm. Two yogurt variants were created: plain yogurt (CMY) and yogurt with added fructooligosaccharides, microbial transglutaminase (a ubiquitous food additive with potential health risks), apple pectin and linseed oil (CMYWA). The syneresis index of these yogurts was quantified through centrifugation, colour changes due to additives were assessed via colorimetric methods and both viscosity and granulometry were determined using precise instrumental techniques. After 7 d refrigerated storage, syneresis was 50% in CMY vs. 30% in CMYWA. Viscosity on day 7 was 205 mPa.s for CMYWA vs. 110 mPa.s for CMY. The CMYWA granule size increased from 2.1 μm on day 0 to 2.8 μm on day 14, while CMY granule size remained stable around 1.9 μm. Lactobacilli counts were higher in CMYWA at 2.8 × 107 CFU/g vs. 2.3 × 106 CFU/g in CMY. In a paired preference test with 37 consumers aged 18–65, CMYWA was significantly preferred over CMY. Sensory evaluations further substantiated that the yogurts with added supplements were more appealing to the palate. The results demonstrate the supplements improved camel milk yogurt properties.