Milk Concentrations Research Articles

Changes in milk productivity and quality of goat milk when including cake and probiotic in the diet

Relevance. One of the solutions to reduce food waste is to try to get the most out of food waste and byproducts. The experiment assessed the milk productivity and milk quality of lactating Nigerian goat goats when using hemp cake on the background of a probiotic substance.Methodology. The research was carried out in 2 stages: in the 1st experiment, the effect on the digestibility of nutritional components of feed was studied as a result of the inclusion of waste from the fat and oil industry in the diet of goats in the amount of 5% hemp (QL) cake, in the 2nd experiment, the enzymatic probiotic drug “Cellobacterin+” (“Biotrof” LLC) was additionally included in the experimental group at a dosage of 10 g/goal /day.Results. According to the research results, it was found that the inclusion of hemp cake in the diet of lactating goat goats did not have a negative effect on milk yield and milk quality, and contributed to a reduction in the cost of its production. The additional introduction of the probiotic drug “Cellobacterin+” into the diet contributed to an increase in milk yield in goats, in the conditions of the Southern Urals, and improved the chemical composition of milk, in particular, increased fat and protein content.

Impact of pasture feeding cows and seasonality on the concentration of selected fat-soluble compounds in milk and their ability to be used as biomarkers of “Grass-Fed” dairy

This study investigated the impact of proportion of pasture in the cow diet on the concentration of selected fat-soluble compounds in milk including β-carotene, lutein, retinol (vitamin A), α-tocopherol (vitamin E) and zeaxanthin. Bulk tank milk samples (n = 102) were collected weekly (n = 34) across an entire lactation from three herds operating either a high (GRS), medium (PMR) or no pasture allowance (TMR) feeding system. Concentrations of β-carotene and lutein increased significantly with increasing pasture allowance, with a > 2 fold increase of β-carotene in milk, between high and no pasture allowance treatments. GRS feeding system resulted in milks with higher concentrations of retinol, α-tocopherol, and zeaxanthin, compared to both PMR and TMR systems. A biomarker model based on the fat-soluble compounds concentration in milk, demonstrated excellent differentiation of high pasture allowance derived milks from that of medium and no pasture milks, with area under the curve scores of 0.955 and 0.971 respectively. Strong correlations were observed between the concentrations of lutein and zeaxanthin in milk and the milks corresponding yellow colour, while a significant correlation was exhibited between β-carotene and b*-value. Such correlations with milk colour may have a significant impact on the consumer preference of milk and dairy products produced therefrom.

Detection of urea in milk by urease-inorganic hybrid nanoflowers combined with portable colorimetric microliter tube.

Asimple one-pot green synthesis method was used to prepare urease-inorganic hybrid nanoflowers (UE-HNFs), which had a high surface-to-volume ratio to improve enzyme catalytic efficiency and make urease reusable. A portable colorimetric microliter tube based on urease-inorganic hybrid nanoflowers (UE-HNFs-PCMT), as an urea colorimetric biosensor, was developed for determining urea concentration in milk. The combination of urea colorimetric biosensor and asmartphone is usedfor capturingthe colour change of milk after reaction. There was a good linear relationship between colour intensity of the image (Δ intensity) and urea concentration (43-600mg L-1), with a detection limit of 12.81mg L-1. UE-HNFs-PCMT has the advantages of no need for complex equipment, easy operation, reusability, low detection cost, good portability, and environmental friendliness and can achieve urea detection in milk.

Characterization and monitoring of changes during lactation in the profile of multiple bioactive compounds of milk from grazing mares.

Mare milk has often been considered a food product with potential functional properties. However, the bioactive compound composition of mare milk, including vitamins and other minor bioactive compounds, as well as factors affecting this composition have scarcely been studied. Therefore, the present study aimed to characterize the changes during lactation in the content of water- and fat-soluble vitamins and total polyphenols, and the total antioxidant capacity of mare milk from semi-extensive farms. A total of 310 individual milk samples from 18 mares belonging to three commercial farms and 12 lactation times were analyzed. Ascorbic acid (vitamin C), thiamine (vitamin B1), riboflavin (vitamin B2), nicotinic acid and niacinamide (vitamins B3), pantothenic acid (vitamin B5), pyridoxal and pyridoxine (vitamins B6), folic acid (vitamin B9), cyanocobalamin (vitamin B12), tocopherols and tocotrienols (vitamin E) and retinol and retinyl esters (vitamin A) were quantified using liquid chromatography. Total polyphenols and antioxidant capacity assays were analyzed using spectrophotometry. The concentration of most bioactive compounds tended to decline as lactation progressed, with the exception of polyphenols and the total antioxidant capacity that oscillated during lactation. On the other hand, the effect of the different semi-extensive management of the farms was only significant for vitamin B3 content. To the best of our knowledge, the present study provides the most in-depth description of the vitamin profile of mare milk as well as new insights into polyphenol content and antioxidant capacity of mare milk. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of pre- and postpartum dietary fat sources (soybean oil versus linseed oil) on lactation performance and blood metabolites in transition dairy cows

This study investigated the effects of supplementation with two calcium salt fatty acid sources (soybean oil (CaSO) and linseed oil (CaLN)) before and after parturition on lactation performance and blood metabolite profiles in dairy cows. A study was conducted with twenty-four multiparous Holstein cows (parity = 3.12 ± 0.9 and Backfat thickness = 21.77 ± 1.98) that were divided into a 2 × 2 factorial design 21 days before expected calving. The aim was to investigate the interplay between prepartum (CaSO or CaLN, at 2 % of dry matter) and postpartum (at 1.4 % of dry matter) fat supplementation on lactation performance and blood metabolite profiles. Initially, cows were grouped according to the source of prepartum fat (either CaSO or CaLN, with 12 cows in each group). Postpartum, these groups were further subdivided according to whether the fat source was administered continuously (LN-LN, SO-SO) or alternately (LN-SO, SO-LN) over a 28-day period. This resulted in four different treatment groups, each with six cows. The fat supplements contained 84 % fat and 9 % Ca. No statistically significant differences were found in dry matter intake (DMI), colostrum yield or most concentrations of blood metabolites (insulin, cholesterol, glucose, triglycerides, total protein, albumin, β-hydroxybutyric acid (BHB), non-esterified fatty acids (NEFA), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and urea-N). However, cows fed CaSO prepartum had a significantly higher plasma concentration of insulin-like growth factor-1 (IGF-1) than cows fed CaLN. Cows fed CaSO had higher backfat thickness (BFT) from day −21–0 than those fed CaLN (P = 0.05). Notably, cows in the SO-SO group lost the most weight, while cows in the SO-LN group lost the least, especially on days 21 and 28 postpartum (P = 0.05). Switching from soybean oil prepartum to linseed oil postpartum (SO-LN) significantly increased milk production in the first 28 days of lactation compared to other diets. In addition, the fat content in milk was influenced by the type of fat supplementation prepartum, with cows receiving CaSO having a lower milk fat percentage than those receiving CaLN (P < 0.05). The results on blood parameters suggest potential benefits of the SO-LN diet for postpartum cows, as emphasized by stable BHB concentrations and the highest IGF-1 concentrations, especially without the elevated BHB concentrations typically associated with the SO-SO diet. The blood concentrations of total protein, urea-N, triglycerides and NEFA were not affected by the treatments. Also, the dietary change did not adversely affect liver function, as shown by unchanged AST and ALT concentrations. Therefore, the results suggest that a dietary intervention involving the administration of soybean oil prepartum and switching to linseed oil postpartum (SO-LN strategy) has the potential to improve milk yield during the early lactation period.

Investigating the Transfer of Lisinopril into Human Milk: A Quantitative Analysis.

Lisinopril is commonly prescribed to manage conditions such as hypertension and heart failure. While concerns about fetal toxicity have traditionally limited the use of lisinopril in women of reproductive age, recent ACOG guidelines promote aggressive treatment of hypertension, which may require the use of pharmacologic agents not previously considered in the postpartum period. We aimed to estimate infant exposure to maternal lisinopril via breastmilk and report the tolerance of the breastfed infant. Five volunteers taking lisinopril provided samples of their human milk and their associated health information for research through the InfantRisk Center Human Milk Biorepository. The milk pharmacokinetics of lisinopril were measured using liquid chromatography-mass spectrometry. The mean milk concentration of lisinopril was 0.49 ng/mL per 10 mg daily dose. The Relative Infant Dose (RID) was 0.06% for lisinopril, more than 100 times lower than the standard 10% safety threshold. The minimal transfer of lisinopril into human milk in this study suggests the drug is unlikely to pose a clinically significant risk to healthy breastfed infants.

Association of healthy eating index (HEI), alternative healthy eating index (AHEI) with antioxidant capacity of maternal breast milk and infant’s urine: a cross-sectional study

Maternal dietary quality may alter the nutrient content of breast milk. In this study, we aimed to investigate the relationship between the healthy eating index (HEI) and alternative healthy eating index (AHEI) of a breastfeeding mother’s diet with the antioxidant profile of her breast milk and her infant’s urine. This study included 300 healthy mother-infant pairs. The participants’ dietary intake was estimated using a validated semi-quantitative food frequency questionnaire. The diet quality of participants was assessed using the HEI and AHEI. The total antioxidant content of the breast milk and infant’s urine was evaluated using ferric reducing antioxidant power (FRAP), 2, 2′-diphenyl-1-picrylhydrazyl (DPPH), thiobarbituric acid reactive substances (TBARs), and Thiol quantification assays. After adjusting for confounding factors, the odds of a low malondialdehyde (MDA) content of breast milk were significantly higher in the highest quartile of HEI than in the lowest quartile. The odds of low DPPH and FRAP in infant urine decreased in the highest quartile of HEI compared to the lowest quartile. No significant relationship was found between AHEI and antioxidant levels of breast milk and the infant’s urine. Our findings demonstrate that a high quality diet of breastfeeding mothers, identified by a higher HEI, can affect the oxidant-antioxidant balance of a mother’s breast milk and her infant’s urine.

Prepartum supplementation of dairy cows with inorganic selenium, organic selenium or rumen-protected choline does not affect carotenoid composition or colour characteristics of bovine colostrum or transition milk.

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.

Impact of diferent types of selection on the milk productivity of Kostroma breed cows

The article studies the influence of homogeneous and heterogeneous selection on the milk productivity of first-calf cows (milk yield, fat and protein content in milk). The object of research is cattle of the Kostroma breed. The research methods were zootechnical, population-genetic and analytical using computer programs IAS “SELEX” Multifarm and BON-MilkRegion. The modern cattle breeding base in the Kostroma region is represented by three breeding plants and two breeding reproducers. In 2022, the Karavaevo Breeding Farm JSC received 9,297 kg of milk per cow, the Minskoe LLC pedigree reproducer received 7,371 kg of milk, and the Rodina collective farm, Gridino and Agrofirma Planet LLC received more 6000 kg of milk. Record milk yields reach 15,000 kg of milk or more in 305 days of lactation. The following lines have been identified as promising in the Kostroma breed: lines Ladka 2537 and Kursa 3722, related groups Master 106902, Meridian 90927 and Concentrate 106157. To improve the productive qualities of dairy cattle, it is necessary to use both intraline selection and cross-lines, taking into account their compatibility. In breeding farms, using homogeneous selection, high productivity indicators were obtained: in terms of milk yield - from first-calf heifers of the related groups Laird, Concentrate and Meridian, in terms of fat and protein content in milk - Laird and Ladka. With heterogeneous selection, the best combinations were identified across farms.

Dielectric spectroscopy technology combined with machine learning methods for nondestructive detection of protein content in fresh milk.

To quickly achieve nondestructive detection of protein content in fresh milk, this study utilized a network analyzer and an open coaxial probe to analyze the dielectric spectra of milk samples at 100 frequency points within the 2-20GHz range, focusing on the dielectric constant ε' and the dielectric loss factor ε''. Feature variables were extracted from the full dielectric spectra using the successive projections algorithm (SPA), uninformative variables elimination (UVE), and the combined UVE-SPA method. These variables were then used to develop partial least squares regression (PLSR), support vector machine (SVM), decision tree (DT), random forest (RF), and least squares boosting (LSBOOST) models for predicting protein content. The results showed that ε' decreased monotonically with increasing frequency, while ε'' increased monotonically. The UVE-SPA method for feature extraction demonstrated superior performance, with the UVE-SPA-PLSR model being the best for predicting milk protein content, achieving the highest RC 2=0.998 and RP 2=0.989 and the lowest RMSEC=0.019% and RMSEP=0.032%. This study provides a theoretical reference for evaluating milk quality and developing intelligent detection equipment for natural milk.

Effects of organic and inorganic selenium mixes in pregnant sows on piglet growth, selenium levels in serum and milk, and selenium deposition in newborn piglet tissues.

This study was conducted to evaluate the effects of organic and inorganic selenium mixes in pregnant sows on piglet growth, selenium levels in serum and milk, and selenium deposition in newborn piglet tissues. A total of 44 multiparous sows (Yorkshire×Landrace) with average body weight (BW), backfat thickness, and parity were assigned to one of the three treatments with 14 or 15 sows per treatment in a completely randomized design. The treatments were as follows: i) Control, corn-soybean meal-based diet with no addition of selenium premix; ii) ISOS(mixed inorganic selenium and organic selenium) 30, a basal diet supplemented with 0.15 ppm of inorganic Se and 0.15 ppm of organic Se; iii) ISOS50, a basal diet supplemented with 0.25 ppm of inorganic Se and 0.25 ppm of organic Se. At day 21 of lactation, supplementing a high level of mixed Se at 0.50 ppm resulted in higher piglet BW and weight gain than adding a low level of mixed Se at 0.30 ppm (p<0.05). Selenium concentration of colostrum in sows fed ISOS50 diet was significantly higher than those in sows fed ISOS30 diet (p<0.05). Selenium concentrations in the serum at days 90 and 110 of gestation and 24 hours postpartum were highest when sows were fed ISOS50 diet (p<0.05). Additionally, increasing levels of mixed Se led to an increase in piglet serum Se concentration at 24 hours postpartum (p<0.05). Before ingesting colostrum, piglets from sows fed a mixed selenium (Se) diet had significantly higher kidney Se concentrations compared to those from the control group, with the ISOS50 treatment showing the most significant difference (p<0.05). Supplementation of the gestation diet with 0.5 ppm of mixed Se may improve piglet growth performance, increase Se concentrations in milk, and enhance Se status in the serum of sows, as well as in the serum and tissues of their offspring.

Flavonoids in breast milk and their absorption, metabolism, and bioactivity in infants.

Flavonoids are present in plant foods such as vegetables and fruits and exhibit various physiological effects, including antioxidant and anti-inflammatory properties. Ingested flavonoids are absorbed from the intestinal tract and circulated in the blood. Some studies have indicated the presence of flavonoids in breast milk. However, information on their metabolites and concentrations in breast milk and the subsequent transfer to and physiological functions in infants is limited. Therefore, this review presents a compilation of recent findings on the transfer of flavonoids to infants via breast milk and their bioactivities.

Composition and Antioxidant Status of Human Milk of Women Living in Bydgoszcz (Poland).

The aim of this study was to compare cortisol concentrations, nutritional composition, and the antioxidant status of human milk of women living in Bydgoszcz (Poland), taking into account maternal factors (fertility, area of residence, economic activity, and breastfeeding period). The basic composition of human milk was evaluated using the MIRIS HMATM analyzer. The level of cortisol was determined by the enzyme-linked immunosorbent method. In order to determine the antioxidant activity, the DPPH radical method was used. It was observed that the concentration of cortisol in human milk in the group of women living in the city center was higher compared to the milk of women living on the outskirts of the city. In the group of women breastfeeding from 3 to 5 weeks after childbirth, the concentration of cortisol in milk was higher compared to the group of women breastfeeding less than 12 months of age and compared to the group of women lactating over 12 months of age. The antioxidant status of human milk was highest in the group of professionally active women and in the group of breastfeeding women from 3 to 5 weeks after childbirth. The basic composition and the caloric value of human milk differed statistically significantly in the study groups. Based on this study, it can be concluded that the composition and antioxidant status of human milk depends on maternal factors (fertility, professional activity, area of residence, and breastfeeding period). Higher cortisol concentrations in breast milk are probably determined by the area of residence (city center and associated higher noise/sound and stress levels) and lactation period (hormonal imbalance, fatigue, and postpartum period). Milk from economically active women shows greater protection against reactive oxygen species compared to milk from inactive women, protecting against the occurrence of diseases of civilization. Milk from breastfeeding women over 12 months of age also shows protection against reactive oxygen species, despite the fact that the highest level of antioxidant status of human milk occurs in the initial period of lactation.

Dietary supplementation with pterostilbene activates the PI3K-AKT-mTOR signalling pathway to alleviate progressive oxidative stress and promote placental nutrient transport

BackgroundProgressive oxidative stress easily occurs as a result of a gradual increase in the intensity of maternal metabolism due to rapid foetal development and increased intensity of lactation. However, studies on the effects of processive oxidative stress on nutrient transport in the placenta have received little attention. The present study was conducted on sows at 85 days of gestation to study the effects of pterostilbene (PTE) on maternal oxidative stress status and placental nutrient transport.ResultsPTE increased the antioxidant capacity and immunoglobulin content in mothers’ blood and milk, reduced the level of inflammatory factors, and improved the nutrient content of milk. PTE also reduced sow backfat loss and the number of weak sons, and increased piglet weaning weight and total weaning litter weight. We subsequently found that PTE enhanced placental glucose and fatty acid transport and further affected glycolipid metabolism by increasing the expression of LAL, PYGM, and Gbe-1, which activated the PI3K phosphorylation pathway. Moreover, PTE addition altered the relative abundance of the Firmicutes, Proteobacteria, Parabacillus, and Bacteroidetes-like RF16 groups in sow faeces. PTE increased the levels of acetate, propionate, butyrate and isovalerate in the faeces.ConclusionsThese findings reveal that the addition of PTE during pregnancy and lactation mitigates the effects of processive oxidative stress on offspring development by altering maternal microbial and placental nutrient transport capacity.Graphical

Dynamics of 137Cs concentrations in cow milk in the districts of Bryansk region

The publication continues the series of research addressed to the dynamics of 137Cs concentrations in agricultural products after the Chernobyl accident. The purpose of the present paper was to analyze the data describing the changes of 137Cs concentrations in cow milk. The information on countermeasures in animal breeding is presented, the system of radiological monitoring of milk contamination is described. It is shown that the dynamics of 137Cs concentrations in milk was seriously affected by the implementation of agrotechnical and veterinary measures. Effective half-lives of 137Cs concentrations in milk in the first period after the accident (1987-1992) ranged from 1 to 2.0 years. In the subsequent period (1991-2015), the reduction of milk contamination slowed down and the half-lives ranged from 5 to 25 years depending on the scope of remediation works and 137Cs aging in the soil.

Study on Vitamin K Levels in Mature Milk of Chinese Lactating Mothers.

This study sought to understand the levels of vitamin K in the mature milk of Chinese lactating mothers, thereby providing a foundation for the development of appropriate intake (AI) of vitamin K for infants aged 0-5 months. Five hundred healthy lactating mothers were selected from the mature milk bank established by the Chinese Maternal and Infant Nutrition and Health Cohort by using a simple random sample procedure. Relevant information about lactating mothers and their infants was obtained by a questionnaire survey. Vitamin K1 and vitamin K2 (MK-4 and MK-7) in mature milk were determined by liquid chromatography-tandem mass spectrometry. The total concentration of vitamin K in mature milk was 4.50 (2.85-6.33) ng/mL. The concentrations of vitamin K1, vitamin K2, MK-4, and MK-7 were 2.81 (1.66-4.39) ng/mL, 1.37 (0.75-2.11) ng/mL, 1.20 (0.58-1.97) ng/mL, and 0.13 (0.08-0.19) ng/mL, respectively. The concentration of vitamin K1 was highest and the concentration of MK-7 was lowest. The concentrations of vitamin K2 and MK-4 in mature milk from the south were significantly higher than those in mature milk from the north. The total vitamin K, vitamin K2, and MK-4 concentrations in mature milk of lactating mothers residing in urban areas were higher than those in rural areas. There was a tendency for the concentration of total vitamin K and vitamin K1 to increase with the mother's age. Moreover, the concentration of MK-4 in mature milk was highest in summer, followed by spring and winter. The levels of vitamin K1 and MK-4 in mature milk were found to be affected by lactation stage; they were highest at 91-120 days and lowest at 31-60 days. Based on the concentration of vitamin K in mature milk found in this study, it is recommended that the appropriate intake of VK for Chinese infants aged 0-5 months is 3.49 μg/d (2.18 μg/d for VK1 and 1.06 μg/d for VK2).

High-pressure processing and heat treatment of Murrah buffalo milk: Comparative study on microbial changes during refrigerated storage

This study aims to evaluate the effect of high-pressure processing (HPP) (500 and 600 MPa for 3 min and 5 min) on the microbial changes of Murrah buffalo milk in comparison to heat treatment (72 °C for 15 s of holding time) during refrigerated storage of 28 days. The results indicated that the total plate count (TPC) of raw milk at day 0 was 5.5 ± 0.6 log10 CFU/mL. At day 0, heat treatment lowered TPC to 3.9 ± 0.6, while HPP treatment was in the range of 4.1 ± 0.3 to 4.8 ± 0.6 log10 CFU/mL. Similarly, lowered yeast and mold count and lactic acid bacteria were noted in heat- and HPP-treated milk samples compared to the control sample during refrigerated storage. There were no Staphylococcus aureus and Escherichia coli detected in heat and HPP-treated samples. Heat or HPP treatment at 600 MPa for 5 min significantly extended the shelf-life of Murrah buffalo milk for three weeks at the refrigerated storage. In addition, HPP treatment did not alter the pH, lightness (L* value), protein, or fat content of Murrah buffalo milk during refrigerated storage. Hence HPP at 600 MPa for 5 min could be a suitable alternative to conventional heat treatment.

Non-destructive detection of water adulteration level in fresh milk based on combination of dielectric spectrum technology and machine learning method

To rapidly realize the identification of fresh milk for water adulteration and to predict the amount of water adulteration, this study adopts a coaxial probe and a vector network analyzer to analyze the variation laws of dielectric constant ε', dielectric loss factor ε'' and dielectric loss angle tangent tanδ in the range of 2–20 GHz under 100 frequency points. Soft independent modeling of class analogy (SIMCA), Naive Bayes (NB), K-nearest neighbors (KNN), and support vector machine (SVM) models were built based on full dielectric spectra for qualitative testing of adulteration levels in milk. Feature variables of FDS were extracted by using the successive projections algorithm (SPA) and uninformative variables elimination (UVE). Partial least squares regression (PLSR), support vector regression (SVR), and particle swarm optimization least square support vector regression (PSO-LSSVR) models were built for quantitative testing of adulteration levels in milk. The results demonstrate an increasing trend of ε'' and tanδ with increasing frequency and a decreasing trend of ε'. The ε'-SIMCA model achieves the best effect in distinguishing water adulteration in milk, showing accuracy (ACC) of 1, Sensitivity (SNS) of 1, Specificity (SPC) precision (PRE) of 1, and an F1-score (F1) of 1. The tanδ-SPA-PSO-LSSVR model optimally predicts the optimal prediction effect of moisture content of milk, showing an RP2 of 0.994 and an RMSEP of 0.016 %. This study is conducive to building a more comprehensive knowledge system of water adulteration in fresh milk. Its results can provide a theoretical reference in the development of non-destructive detection instruments for natural milk.

Fabrication of MnSnO2 intercalated TA-rGO modified sensor for selective electrochemical detection of chloramphenicol in real samples

Chloramphenicol (CAP), a potent antibiotic capable of inhibiting protein synthesis, presents significant challenges related to long-term dosing and its persistent leaching into the environment, raising concerns about environmental contamination and resistance development. To address this issue, we developed a reliable, low-cost, and biocompatible nanocomposite material comprising tannic acid (TA)-reduced graphene oxide (rGO) intercalated into manganese-doped tin oxide nanoparticles (MnSnO₂ NPs). The structural formation and catalytic activity of the MnSnO₂ NPs/TA-rGO nanocomposite were characterized using field emission-scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. This material exhibits robust interfacial interactions and synergistic effects, resulting in an admirable electrocatalytic reduction response for CAP sensing. The presence of co-interference molecules improved the selectivity performance of the MnSnO2 NPs/TA-rGO-modified glassy carbon electrode. The fabricated exhibited a two linear determination range (0.011–103.43 μmol L−1 and 103.43–1924.16 μmol L−1), with a detection limit (LOD) is 6.7 nmol L−1 and limit of quantification (LOQ) is 12.3 nmol L−1. Furthermore, this sensor demonstrated good sensitivity, admirable reproducibility, repeatability, and storage stability. Finally, the practicability of the fabricated MnSnO2 NPs/TA-rGO glassy carbon electrode sensor was evaluated by analyzing the CAP content in milk, honey, eye drops, biofluids (human serum and urine), and river water, and satisfactory recovery rates of 95.4 %–100.3 % were noted.

Dietary macronutrient composition and partial soybean meal replacement with slow-release urea: Effects on performance, digestibility, rumen fermentation, and nitrogen metabolism in dairy cows

A 2 × 2 factorial arrangement of treatments was used to investigate the interactive effects of dietary macronutrient composition [high-starch, low-fat, low-fiber (HsLFF) than low-starch, high-fat, high-fiber (LsHFF)] and N source [soybean meal (SBM) or partially replaced by slow-release urea (SRU)] on lactation performance, rumen fermentation, N utilization efficiency, nutrient digestibility, blood metabolites, and feeding behavior in cows. A replicated 4 × 4 Latin square design was used involving 12 multiparous Holstein cows (milk yield of 40.5 ± 5.6 kg/d, BW of 590 ± 20 kg; 81 ± 12 d in milk). The HsLFF diet contained 300 g/kg starch, 31.3 g/kg fat, and 301 g/kg NDF, without straw or additional fat. In contrast, the LsHFF diet contained 195.5 g/kg starch, 60.8 g/kg fat, and 367.5 g/kg NDF, enriched with wheat straw (100 g/kg), and additional fat (34 g/kg). The diets were formulated to be iso-nitrogenous and isocaloric. Cows fed the HsLFF diet had greater DM intake, digestibility of DM and CP, milk yield and milk protein %, but lower intakes of NDF, and physically effective NDF, and milk fat % than cows fed the LsHFF diet. Replacing SBM with SRU significantly increased milk solids yield without affecting other lactation performance or BW. Cows fed the LsHFF diet had higher ruminal pH and branched-chain VFA proportions but lower total VFA concentrations compared with the HsLFF diet, while those on the LsHFF-SRU diet had the highest ruminal ammonia levels. Compared with the HsLFF diet, cows fed LsHFF had lower NE intake, milk energy output and energy requirement for maintenance, although energy balances were similar among groups. The HsLFF diet improved N utilization, resulting in higher N content in milk and lower N excretion in feces. Blood metabolite studies showed significant interactions between the main factors, particularly for blood glucose and creatinine, with the lowest levels in cows fed the LsHFF-SRU and LsHFF-SBM diets. In addition, alanine aminotransferase levels were higher in cows fed the LsHFF diet than in cows fed the HsLFF diet. This could indicate early-stage liver stress due to the metabolic imbalance caused by a high-fat, low-starch diet, which can alter energy metabolism. Cows on the HsLFF-SRU diet had the highest glucose levels, indicating possible changes in carbohydrate metabolism or a higher metabolic rate. The concentration of BUN increased steadily after feeding in the LsHFF diet and peaked after 4 h in the LsHFF-SRU diet, with no difference between N sources in the HsLFF diet. Partial replacement of SRU with SBM had no effect on BUN. The interaction between the main factors had a significant effect on MUN content, which was highest in LsHFF-SRU and lowest in HsLFF-SRU, with no difference between the N sources in the HsLFF diets. Overall, while diets with reduced starch and increased fiber and fat compromised lactation performance, partially substituting SRU with SBM helped maintain milk production and milk nitrogen efficiency. However, the LsHFF-SRU diet was less efficient in N utilization, as shown by higher levels of ruminal ammonia, BUN and MUN.