This study focuses on the carriage and antibiotic-susceptibility profiles of Gram-positive bacteria in dromedary camel milk. A total of 103 milk samples were collected from apparently healthy female dromedaries in southern Tunisia. Bacterial growth was observed only in 82 of these samples, yielding 86 Gram-positive bacterial isolates. Staphylococcus was the most frequently isolated genus (54/86, 62.8%) with 13% of coagulase-positive staphylococci (CoPS) represented by S. aureus and S. intermedius and 87% of coagulase-negative staphylococci (CoNS) (n = 47) identified as S. simulans, S. xylosus, S. warneri, S. hominus1, S. capitis, S. sciuri and S. equorum. Cellulomonas spp. (16, 18.6%), Lactococcus lactis subsp. lactis (8, 9.3%), Aerococcus viridans (7, 8.5%) and Kocuria rosea (1, 1.1%) were also identified. Staphylococcus species showed the highest resistance to chloramphenicol (50% of samples), followed by clindamycin (42.6% of samples), neomycin and nalidixic acid (40.7% each). No resistance genes were detected for the low levels of resistance to penicillin, oxacillin and cefoxitin. Cellulomonas spp., L. lactis subsp. lactis and A. viridans isolates exhibited moderate frequency of resistance, particularly to aminoglycosides and tetracycline. However, resistances to sulphonamide-trimethoprim, ciprofloxacin, nitrofurantoin, tylosin and rifampicin were rarely detected. Multidrug-resistant (MDR) bacteria were identified in 11.7% of the total isolates, with the higher rates observed for L. lactis subsp. lactis (25% of samples), A. viridans (14.2% of samples) and Cellulomonas spp. (6.25%), while 11% of Staphylococcus isolates were MDR, significantly more in CoPS (28.5%) than CoNS (8.5%). Additionally, MDR rate was higher in older female (p = 0.042) and those raised alongside ruminants (p = 0.030). All tested MDR bacteria exhibited significant combinations of resistance genes, including aph3-IIIa and ant6-Ia for aminoglycosides, cat(pC221) for chloramphenicol, ermA for erythromycin and clindamycin, tetK for tetracycline and drfA for trimethoprim-sulphonamide. Further, comprehensive studies are needed to understand MDR bacteria emergence within camel milk.

The integration of phenotypic, genomic and pedigree data into a single-step model for predicting genomically enhanced estimated breeding values (GEBVs) has become crucial for the accurate genetic evaluation of dairy cattle. This study compared two widely used software implementations, MiXBLUP and BLUPF90IOD3, for the prediction of breeding values using the single-step G-BLUP model based on data from the Polish national evaluation for stature. Four core animal sets were tested, which differed in the selection of bulls and cows. The GEBVs were predicted and validated using different subsets of the population. Both software packages resulted in high correlations (0.89 and 0.97) between full and truncated dataset predictions and similar validation performance, with MiXBLUP exhibiting slightly greater consistency across different sets of core animals. The ranking of the top 50 bulls remained stable across the implementations. This study concludes that both software implementations provide comparable GEBV predictions, suggesting that software choice should consider computational efficiency, cost and modeling flexibility, with MiXBLUP offering additional options for GEBV estimation.

The aim of the experiment reported in this research paper was to determine the influence of the bovine appeasing substance (BAS) on milk yield, energy metabolism, inflammation, and stress in cows during the transition period. Twenty-four multiparous Holstein cows (day 28 pre-partum to 21 postpartum) were distributed randomly into two groups: control (n = 12) and BAS (Secure Cattle®; n = 12). Each animal was administered 5 mL of the product on days 28 and 14 pre-partum and on the day of calving. The feed intake was assessed using automated, individual feeders and the milk yield was determined electronically. Six milk samples were obtained from each animal, which were analyzed for chemical composition and somatic cell count. Six blood samples were obtained per animal for future biochemical analyses (free fatty acids, beta hydroxybutyrate, cortisol, myeloperoxidase and paraoxonase 1). The statistical analyses were conducted with the JMP Pro 14 software, with P ≤ 0.05 being considered as statistical significance. BAS-treated cows showed higher milk yield than controls. Dry matter intake (DMI) during the pre- and postpartum periods was greater for the control than treated group. The BAS group exhibited reduced plasma cortisol postpartum. In conclusion, cows treated with BAS showed higher milk yield, lower DMI, and reduced plasma cortisol concentrations than controls.

The aim of this review is to quantify the strength of evidence for the efficacy of exogenous enzymes (EE) in dairy calf rearing, by systematically identifying, consolidating and discussing existing research on the subject. This review identified 17 articles that measured the effect of EE alone or in combination with another treatment on indicator variables for calf performance, behaviour, health or environmental output; 15 studies realised a positive effect of enzyme supplementation on at least one variable, and one study realised a negative effect of treatment on body parameters. Inconsistent results were noted for effects of EE on growth and feed efficiency. Studies that combined EE with another treatment, did not tend to find performance improvements compared to stand-alone treatments. However, several studies were underpowered which could have limited their ability to detect effects on primary response variables. All papers that measured digestibility found an increase in fibre digestibility from enzyme treatment; however, this did not always result in improved feed efficiency or growth. Reductions in non-nutritive oral behaviour, increased resting time and rumination, were observed in studies measuring calf behaviour, as were enhanced rumen development and reduced cost of calf rearing; suggesting that EE could enhance calf health and welfare, whilst having additional advantages for rearing economics. Future research into the efficacy of EE in dairy calves is worth pursuing. However, a targeted and evidence-based approach to experimental design is required, with due consideration given to enzyme actions and interactions, as well as robust power analysis for sample size.

This study explored the relationship between dairy technology adoption (DTA), crop diversification and food security among smallholder farmers practicing mixed agriculture in Bason Werana Woreda, North Shewa Zone, Amhara Region. A systematic sampling method selected 252 households from two randomly chosen government administrative areas (kebeles), proportional to size. Data were analysed using descriptive statistics and an endogeneity-corrected recursive conditional mixed process regression model to examine bidirectional causation. Findings showed a 34% adoption rate of dairy technology, with improved housing and vaccination being the most common, while artificial insemination and improved breeds had the lowest adoption. The Herfindahl Iindex for crop diversification was 0.31, indicating a lower-middle level. Food security analysis, based on the Food Consumption Score, revealed that 78.57% of households were food secure, while 16.27% and 5.16% had borderline and poor food security, respectively. The regression results indicated that DTA significantly improves food security, and vice versa, but no causal relationship was found between these factors and crop diversification. The study identified key household-level and policy-related variables that are critical for enhancing DTA and addressing food insecurity. Overall, the findings underscore the importance of designing and promoting context-specific, locally optimal agricultural strategies that are closely aligned with household characteristics. Such alignment is essential for advancing dairy sector development and improving the welfare of smallholder farmers in Ethiopia.

Lactotransferrin (LTF), a critical multifunctional glycoprotein, plays an essential role in the immune defence, growth and development, and milk quality of dairy cows. The regulatory mechanisms governing gene expression are intricate, with sequence variations in the promoter region potentially exerting a substantial impact on gene expression. In this study, sequencing analysis of the bovine lactotransferrin promoter region was conducted, leading to the identification of two linked single nucleotide polymorphism (SNP) sites. A significant association between these SNPs and lactotransferrin content was observed in a cohort of 301 Holstein cows. Subsequently, further investigation into the transcriptional activity of various lactotransferrin genotypes was performed by constructing promoter fragments encompassing different lactotransferrin genotypes. The findings reveal that the two SNPs significantly influence the activity of the lactotransferrin promoter, thereby affecting lactotransferrin expression. These results hold substantial implications for advancing our understanding of the regulatory mechanisms underlying lactotransferrin expression and for the genetic enhancement of dairy cows.

This research paper addresses the hypothesis that the in vivo criterion of bovine somatic cell count (SCC) < 200,000 cells/ml milk as a diagnostic marker for healthy mammary tissue is not suitable to be adopted to milk samples taken post slaughter. To study immune mechanisms associated with intramammary infections, we developed a mammary explant model. As SCC is routinely applied to differentiate between healthy and inflamed mammary tissue, donor cows were selected based on their milk SCC obtained in vivo. Furthermore, milk cell differentiation for early mastitis detection via flow cytometry allows identification of leucocyte subpopulations and complements SCC. To replace in vivo examination and allow for post mortem selection of donor cows, this explorative study aimed to investigate how slaughter influences the reliability of SCC and differential milk cell count (DMCC) and to assess their validity as diagnostic markers for udder health in bovine milk samples obtained post slaughter. Therefore, quarter milk samples from cows were obtained in vivo and post mortem and analysed to determine SCC and DMCC and identify major mastitis pathogens. The logarithmized numbers of SCC, non-viable cells, viable cells, lymphoid cells, polymorphonuclear (PMN) and large cells per ml milk were compared using linear mixed-effects models in milk samples obtained from cows in vivo and post mortem. The number of lymphoid cells, PMN and large cells was significantly higher in milk samples obtained post mortem than in vivo, with PMN being the most prominent cell population. Higher milk SCC values measured post mortem might be explained by migration of leucocytes into the periphery during slaughter. This should be considered when modelling intramammary infection in vitro using udder tissue. Reflecting these findings, it is not feasible to endorse SCC as a reliable marker for post mortem selection of donor cows with healthy mammary tissue for in vitro models.

This study tested the effects of the methylenetetrahydrofolate reductase (MTHFR) rs110692574 polymorphism and rumen-protected choline and methionine supplementation on biochemical parameters, milk yield, reproductive performance and health status during the transition period in Holstein cows raised in Türkiye. Genotypes of 356 cows were determined using the tetra-primer amplification refractory mutation system–polymerase chain reaction (ARMS-PCR) method. Following genotyping, 80 cows were selected and assigned to four groups based on nucleotide genotype at two loci (homozygous CC and heterozygous CT) and dietary supplement (choline or choline + methionine). Blood samples were collected on day 21 prepartum, on the day of parturition (day 0), and on day 21 postpartum to measure homocysteine, folic acid, vitamin B12, and non-esterified fatty acid concentrations. beta-hydroxybutyric acid (BHBA) values and production data were obtained from the farms’ routine monitoring records. Statistical analyses were performed using repeated-measures analysis of variance (ANOVA) to assess time-dependent effects, and a general linear model was used for between-group comparisons at the same time points. The frequency of the CT genotype was 12.64%. The polymorphism significantly affected folic acid and vitamin B12 concentrations across different stages of the transition period. Feed supplementation had a significant effect on folic acid concentrations on calving day and on day 21 postpartum, as well as on milk yield on days 100, 200 and 305. Moreover, the polymorphism was significantly associated with folic acid and vitamin B12 concentrations on day 21 prepartum and with BHBA values on day 7 postpartum. This variation was linked to specific health issues that could lead to decreased productivity. In conclusion, genotype-based nutritional strategies were found to play a key role in maintaining metabolic balance and enhancing productivity during the transition period.

The confirmatory factor analysis technique was used to quantify a latent variable for test-day lactation performance (TDLP) in the first parity of Chinese Holstein dairy cows by applying five measurable traits, including test-day milk yield (TDMY), test-day milk fat percentage (TDFP), test-day milk protein percentage (TDPP), test-day somatic cell score (TDSCS) and test-day milk urea nitrogen (TDMUN). The standardised factor loadings of TDMY, TDFP, TDPP, TDSCS, and TDMUN for describing TDLP were 0.46, −0.52, −0.70, −0.14 and −0.19, respectively. Genetic analysis was conducted using a multivariate repeatability model within a Bayesian framework. The posterior means for the heritability and repeatability estimates of TDLP were 0.26 ± 0.02 and 0.34 ± 0.02, respectively. In general, posterior means for heritability and repeatability estimates of the measurable traits were low to medium. The heritability estimates ranged from 0.05 for TDSCS to 0.28 for TDPP, and repeatability estimates ranged from 0.15 for TDMUN to 0.38 for TDMY. The latent variable of TDLP exhibited positive genetic (0.62) and phenotypic (0.40) correlations with TDMY, whereas its genetic and phenotypic correlations with other measurable traits were negative, ranging from −0.96 (TDLP–TDPP) to −0.11 (TDLP–TDSCS). The corresponding phenotypic correlations ranged from −0.85 (TDLP–TDPP) to −0.07 (TDLP–TDSCS). It may be concluded that breeding for higher TDLP might increase TDMY but could reduce milk composition traits. In general, the negative genetic and phenotypic correlations suggest a trade-off between milk quantity (yield) and quality (composition).

Plasminogen is an inactive protease in milk, which can be activated to plasmin. Whole milk contains fat and in response to lipase activity, free fatty acids are released. Free fatty acids are not known to act as an activator for plasminogen. The aim of this study was to determine whether commercial bovine plasminogen could be activated to plasmin by commercial free fatty acids present in milk, and also to determine if plasminogen activators to plasmin are present in abnormal milk using milk agar plates and the Merck protease assay. Fatty acids and activators present in abnormal milk had the ability to activate plasminogen to plasmin, which could, after weeks, harm milk protein stability during extended storage time (ultra-high temperature milk). The milk agar plate technique containing plasminogen could detect plasmin activators present in abnormal milk. This can act as an indicator of high-risk milk being used within the ultra-high temperature milk industry.

This Research Communication reports the physicochemical properties, aflatoxin levels and antibiotic residues in buffalo milk. The milk and feed samples were collected from nine farms in Peninsular Malaysia, with the lactation stage studied in one farm. Buffalo milk composition varied across farms; Petaling Jaya showed high fat and total solids but low protein and solids non-fat (SNF), while Jitra 1 and Seberang Perai 2 exhibited higher protein, casein and SNF. Langkawi and Hulu Langat had higher moisture, ash and lactose levels. Early and late lactation were linked to higher protein and casein. Aflatoxin B1 in feed was undetectable; however, aflatoxin M1, amoxicillin and oxytetracycline were present in milk but below the regulatory limits. These findings indicate that current on-farm management practices are effective in ensuring the safety and quality of buffalo milk, while continuous monitoring remains crucial.

This research paper investigated the hypothesis that the high production of 3-methylbutanal by lactic acid bacteria is achieved not only through a direct metabolic pathway but also via an indirect pathway. 3-methylbutanal is a flavour compound that contributes to the sensory profile of various cheeses, often described as nutty, malty, or chocolate-like depending on its concentration and the cheese matrix. Although it is desired in certain cheese varieties, its acceptability varies among different cheese types. Among the various compounds responsible for this nutty scent, 3-methylbutanal plays a pivotal role. Certain strains of lactic acid bacteria are known to produce 3-methylbutanal from leucine, via both direct and indirect pathways. While it has commonly been assumed that the direct pathway is the primary mechanism, this study reports the discovery of Lactococcus cremoris AJ01, which produces 3-methylbutanal predominantly through an indirect pathway. We first investigated the effects of milk fermentation conditions on 3-methylbutanal and acid production by strain AJ01. The effect of leucine supplementation on 3-methylbutanal production was then examined. Finally, we explored the metabolic pathway responsible for 3-methylbutanal synthesis in this strain, determined the nucleotide sequence of the pyruvate dehydrogenase gene involved in the indirect pathway, and evaluated its enzyme activity to assess its contribution to production. When cultured in milk at 20 °C, strain AJ01 produced titratable acidity at >0.6% and 3-methylbutanal at >6 mg/kg within 18 h. Adding leucine to the milk enhanced 3-methylbutanal production, while excessive leucine supplementation inhibited it. Strain AJ01 exhibited activity of pyruvate dehydrogenase, while no activity of α-keto acid decarboxylase, the direct-pathway enzyme, was detected, suggesting that it produces 3-methylbutanal via the indirect pathway. These findings may contribute to the effective management and enhancement of flavour profiles in fermented dairy products, particularly cheeses.

High-temperature short-time (HTST, 72°C, 15 s) pasteurization can be successfully used for human milk (HM) preservation. The purpose of this study was to compare the effects of different HTST heating methods: microwave (MHTST) and standard convective (CHTST) on macronutrients, fatty acids (FAs), lactoferrin (LF), vitamin C, lysozyme (LZ), α-amylase (α-A) activity, lipid oxidation and antioxidant properties of HM. Regardless of the heating methods, the macronutrients and FA content, LZ activity and antioxidant properties of HM proved to be insensitive to HTST treatment, while the concentration of vitamin C decreased by 42.6% and 50.2%, and the activity of α-A by 6.0 and 7.2% when using MHTST and CHTST, respectively. LF content changed significantly only when CHTST was used (42.3% reduction). There were no negative effects of microwave heating under controlled conditions on the HM components. Satisfactory results regarding the impact of MHTST on HM composition and potential economic benefits suggest that this technology can be applied in HM banks to ensure adequate safety and quality.

The aim of this study was to investigate whether hair can be used as a non-invasive sample material that is less influenced by homeostasis than blood. Blood analysis is an invasive method of assessing trace element status, concentrations can be influenced by homeostasis, and they might not accurately reflect the true status of the animal. Thus, hair samples could play an important non-invasive role in diagnosing chronic deficiencies. The study group included 100 veal calves of a variety of different breeds and crossbreeds aged between 2 and 5 months, consisting of both sexes. Samples were taken to compare different locations and colours of hair. The concentration of trace elements Mn, Fe, Se, Co, Cu, Zn and Mo of different coloured ear and shoulder hair (black, brown and white) were measured, and concentrations were compared with those in the liver, kidney, muscle and blood plasma. All samples were measured with triple-quadrupole collision/reaction cell ICP-MS. This study showed that both hair colour and hair location have an influence on trace element concentration. In this animal series, no strong correlations could be found between trace element concentrations in hair and other tissues, suggesting that such an approach is only feasible when a heterogeneous animal series is used. Whether hair is a feasible sample material for trace element analysis cannot be conclusively answered; a larger sample size and further studies on other influencing factors would have been required. In addition, the procedure would need to be highly standardized, as both sampling localization and hair colour appear to have an influence.

This study investigated the hypothesis that a natural biopolymer system could simultaneously mitigate and detect aflatoxin M1 (AFM1) contamination in milk. AFM₁, the hydroxylated metabolite of aflatoxin B₁, is a potent carcinogen that remains stable during milk processing and continues to pose significant food safety concerns. The research therefore aimed to determine the prevalence of moulds and AFM1 in raw buffalo and cow milk from Giza Governorate, Egypt, and to evaluate the performance of a novel natural biopolymer complex composed of chitosan, β-cyclodextrin, AFM₁-specific antibodies and anthocyanins, designed for dual functionality in AFM₁ adsorption and diagnostic signal enhancement. Total mould counts were assessed following the ISO protocol, while milk composition and somatic cell count (SCC) were determined by Bentley 150 scan. AFM1 detection was initially performed by thin-layer chromatography (TLC) and subsequently quantified by a validated reversed-phase high-performance liquid chromatography (HPLC) method. The HPLC method exhibited excellent performance with linearity (R2 = 0.99999), sensitivity (LOD 0.002 µg/L, LOQ 0.007 µg/L) and precision (RSD ≤ 1.5%). The lowering in milk compositional quality was statistically significant (P < 0.05) with elevated SCC in AFM₁-positive samples. Screening revealed AFM1 contamination in 28% of buffalo and 56% of cow milk samples, with mean concentrations of 0.084 µg/L and 0.188 µg/L, respectively. Application of the natural biopolymer achieved AFM1 reductions of 65–73% in buffalo milk and 83–90% in cow milk, while anthocyanins within the polymer provided concentration-dependent diagnostic signals. Sensory evaluation indicated that treated milk maintained acceptable organoleptic properties without adverse effects on compositional quality. These findings emphasise the prospective use of natural biopolymers as dual-function analytical and mitigation tools for AFM1 in milk, offering a reliable approach for routine milk safety monitoring.

This study aimed to evaluate the microclimatic conditions of natural shading provided by Ipês (Handroanthus heptaphyllus [Vell.] Mattos), and of an artificial shading structure characterized by the combination of an aluminized net on the outside and a black polypropylene net on the inside. In addition, their effects were analysed with respect to the physiological and behavioural responses of Holstein cows kept at pasture in a tropical climate. Two paddocks were used, one with trees and the other with trees and an artificial shade structure. Eight multiparous cows were evaluated over 20 non-consecutive days and selected according to their predominant coat colour: four with predominantly white coats and four with predominantly black coats. The experimental days were classified as very hot, with radiation above 625 Wm−2; and hot days, with radiation between 300 and 625 Wm−2. The mean radiant temperature (°C), the radiant heat load (Wm−2) and the black globe humidity index were calculated. The mean radiant temperature for artificial shading was lower for all days (P < 0.05), with values below 30°C during daylight hours. The radiant heat load was lower under the artificial shading structure regardless of the day (P < 0.05), with values below 470 Wm−2. When compared microclimatically with natural shading, artificial shading was more efficient (P < 0.05) in reducing mean radiant temperature and radiant heat load. Although behavioural variation (P < 0.05) was observed, these results were related to the difference in coat pattern. Animals with predominantly black coats grazed in the early morning hours and sought protection as thermal comfort levels rose.

This Research Paper investigates the hypothesis that variations in genes related to immune system function may influence the antioxidant potential of cow milk. The present study analysed the association between genotypes at selected osteopontin (OPN), chemokine receptor type 1 (CXCR1) and L-selectin (SELL) gene loci and the total antioxidant capacity of milk from 519 Polish Holstein–Friesian black-and-white cows. Genotyping at the genomic loci employed the polymerase chain reaction-restriction fragment-length polymorphism method, while the Trolox-equivalent antioxidant capacity method was used to measure milk TAC. The statistical method involves analysis of variance with Dunnett's post hoc tests. The results of analyses showed that the chosen genotypes as a TT (CXCR1 – c.291C > T), TT (CXCR1 – c. + 365 T > C) and TT (SELL – c.567C > T) combination was significantly associated with higher mean milk antioxidant capacity (P < 0.039). Therefore, analysing polymorphisms in genes related to the bovine immune system appears to be important in the context of selecting animals that produce milk with enhanced functional properties.