Journal of Dairy Research最新文献

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 communication aimed to describe the concentrations of major bone metabolic markers in colostrum from dairy cows on the day of calving and to clarify their associations with parity and the incidence of milk fever (MF). Forty-five Holstein cows were categorized into three groups based on parity: P1 (first calving; n = 18), P2 (second calving; n = 11) and P3 (third to sixth calving; n = 16). Within the P3 group, 6 cows developed MF within a few hours after calving (MF cows), whereas 10 showed no signs of MF (non-MF cows). Concentrations of osteoprotegerin (OPG), tartrate-resistant acid phosphatase isoform 5b (TRAP5b), cross-linked N-telopeptide of type I collagen (NTx), bone-specific alkaline phosphatase (BAP or ALP3) and calcium (Ca) were measured. With increasing parity, serum concentrations of Ca, ALP3 and TRAP5b significantly declined (P < 0.001-0.05). Parity also significantly influenced colostral bone markers: colostral BAP was highest in the P2 group (P < 0.01). Among P3 cows, serum Ca concentrations were significantly lower in MF cows than in non-MF cows, although no significant differences were observed in colostral Ca concentrations. Although no statistically significant differences were detected in other colostral bone metabolic markers between MF and non-MF cows, colostral OPG concentrations tended to be higher in MF cows (P = 0.088). Across all 45 cows and within the P3 group, colostral OPG was moderately and positively associated with serum OPG, as well as with both colostral and serum NTx concentrations. In conclusion, colostral OPG concentration in parturient cows with three or more parities may serve as a useful indicator for reflecting the bone metabolic status of dairy cows with and without MF.

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.

This study aimed to evaluate the effects of cashew nut shell liquid (CNSL) levels in goats' diets on their performance and milk quality. We hypothesize that the inclusion of CNSL in lactating goats' diets may influence the biohydrogenation process, increasing the levels of CLA (i.e., C18:2-c9 t11 isomer) and its precursors (rumenic acid, C18:1-t11) in goat milk. Eight lactating Saanen goats were assigned to a replicated 4 × 4 Latin square design with four diets: a control diet with no inclusion of CNSL and diets with the inclusion of 5, 15 and 20 g of CNSL per kg/dry matter. Intake of major nutrients was not different between diets, and no difference was observed in apparent total-tract digestibility of nutrients, except that ether extract intake increased linearly (P < 0.001) with CNSL inclusion rate. Milk yield (2.39 kg/day) and milk composition were not affected by the inclusion of CNSL. The milk fatty acids (FAs) C18:1-t9 (P = 0.001) and C18:3-n3 (P = 0.007) presented higher concentrations in milk with CNSL inclusion. The partial sum of omega-3 FA (Σn3), PUFA/SFA ratio and n6:n3 and n3:n6 ratios showed linear responses (P < 0.05) with increasing levels of CNSL. In conclusion, the CNSL affected the milk lipid profile in a way that is favourable to human health. CNSL may be a viable strategy to enhance milk with bioactive FAs.

The trend towards health-conscious consumption has led the food industry to enhance the nutritional content of staple products like yoghurt. This review explores the integration of nutrient-rich fruit peels into yoghurt, emphasizing both health benefits and technological advancements. Fruit peels, which are frequently discarded as agro-industrial waste, are abundant in nutrients, antioxidants and dietary fibres, which can boost yoghurt's nutritional profile. Incorporating fruit peels not only supports waste reduction and sustainability but also contributes to the added value of yoghurt products. Technological innovations have made it possible to efficiently process and incorporate these peels while preserving their benefits. The review evaluates various methods such as fermentation, drying and grinding and their effects on yoghurt's taste, texture and shelf-life. Additionally, it considers consumer acceptance and market potential for these enhanced yoghurts. Overall, this approach highlights the promise of fruit peels as functional ingredients, promoting health benefits and advancing yoghurt production technologies.

The aim of this study was to develop a fermented dairy beverage based on buttermilk, enriched with prebiotic fibre and supplemented with protein, and to evaluate its physicochemical and microbiological properties. Four treatments were formulated: control (T1), inulin (T2), whey protein (T3), and inulin plus whey protein (T4). During 36 days of refrigerated storage, pH, titratable acidity, syneresis, protein content, lactic acid bacteria count, and rheological behaviour were evaluated. Treatments T1 and T2 exhibited minimal differences across all parameters, confirming the feasibility of adding inulin to dairy beverages without altering their characteristics. Treatments T3 and T4 showed significant differences in all parameters except microbial counts, displaying higher pH, titratable acidity, protein content, and viscosity, and lower syneresis, highlighting the influence of protein supplementation on product properties. Overall, the results demonstrated that the use of buttermilk to produce dairy beverages is promising and may lead to a new variety of healthy products for consumption.