Lactose Content Research Articles

EFFECT OF MASTITIS ON MILK COMPOSITION OF CROSS-BRED (HOLSTEIN FRIESIAN X CHOLISTANI) AND SAHIWAL CATTLE

The present study was designed to investigate the effect of mastitis on various components including fat percentage, protein, total solids, solid not fat, pH, specific gravity and lactose content in milk of cross-bred (Holstein Friesian × Cholistani) and Sahiwal cattle. A total of 376 milk samples (excluding blind and nonfunctional teats) from 100 cows (50 cross-bred and 50 sahiwal) were collected aseptically. Animals of different ages, parity and stages of lactation were selected under field condition. The diagnosis of subclinical mastitis was done on basis of Surf Field Mastitis Test. For bacterial examination of milk, the samples were grown in laboratory and various biochemical tests were performed. The results of the present study indicated that solid not fat (SNF) of mastitic sahiwal and cross-bred cattle and total solids percentage of normal and mastitic cattle were significantly reduced as the severity of mastitis increased in animals. The milk pH of normal and mastitic cattle including both sahiwal and cross-bred was significantly increased in severe cases of mastitis. The specific gravity of normal and mastitic milk samples showed that there was no significant difference in specific gravity as compared to normal. The protein percentage of normal and mastitic cattle including both sahiwal and cross-bred cattle indicated that protein concentration was significantly reduced in severe cases of mastitic animals. The findings of present study highlighted that mastitis cause major alterations in composition of milk leading to poor quality of the milk.

IPTG-induced high protein expression for whole-cell biosynthesis of L-phosphinothricin.

Biocatalytic production of L-phosphinothricin (L-PPT) is currently the most promising method. In this work, we use an Escherichia coli strain coexpressing of D-amino acid oxidase and catalase (E. coli DAAO-CAT) to oxidation biocatalytic D-PPT to PPO, then use the second E. coli strain coexpressing glutamate dehydrogenase and formate dehydrogenase (E. coli GluDH-FDH) to reduce biocatalytic PPO to L-PPT. We compared the effects of different concentrations of IPTG or lactose on protein expression and enzyme activity in 5 L fermenter. The best induction conditions for E. coli DAAO-CAT were 0.05mM IPTG, induction for 18h at 28°C. The specific enzyme activities of DAAO and CAT were 153.20 U g-1 and 896.23 U g-1 , respectively. The optimal induction conditions for E. coli GluDH-FDH were 0.2mM IPTG, induction for 19h at 28°C. The specific enzyme activities of GluDH and FDH were 41.72 U g-1 and 109.70 U g-1 , respectively. The 200mM D-PPT was biocatalyzed by E. coli DAAO-CAT for 4h with space-time yield of 9.0g·L-1 ·h-1 and conversion rate of over 99.0%. Then 220mM PPO was converted to L-PPT by E. coli GluDH-FDH for 3h with space-time yield of 14.5g·L-1 ·h-1 and conversion rate of over 99.0%. To our knowledge, this is the most efficient biocatalytic reaction for L-PPT production. We found that IPTG has advantages compared with lactose in the enzyme activity and biomass of E. coli DAAO-CAT and E. coli GluDH-FDH, and IPTG is more environmentally friendly. Our data implicated that IPTG can replace lactose in terms of economic feasibility and effectiveness for scaled-up industrial fermentations.

The effect of differences in lactation period and milking time on milk production and quality of Saanen Etawa Crossbreed Goats (Sapera)

This research aims to analyze the effect of different lactation periods and milking time on milk production and quality in Sapera goats (Saanen Peranakan Etawa). The research was carried out from September 2021 to January 2022. The materials used were 8 Sapera goats in the II lactation period and 8 Sapera goats in the III lactation period by collecting milk samples in the morning and afternoon. Milk quality analysis of Sapera goats milk using Lactoscan SAP (Nova Zagora, Bulgaria). The following parameters observed were milk production, fat content, protein content, lactose content, and density. This study used the Nested Design method, namely the nested milking time in the lactation period. The research data were analyzed statistically using T Test. The results showed that the difference in lactation period in Sapera goats could affect the density of milk (p<0.05). Differences in milking time in Sapera goats can affect milk production, milk protein content, milk lactose content and density (p<0.05). The conclusion of this study was that Sapera goats milk in the III lactation period showed a higher density of milk than II lactation period. Sapera goat milk yield from morning milking associated higher milk production, lactose content and density than the afternoon milking, but the protein content in the afternoon milking time was higher than the morning milking time and was still in the normal range. Milk fat content and milk protein content have met the standard of SNI No. 01–3141–2011 and Thai Agricultural Standard (TAS) 6006-2008.

Comparative analysis of total protein, casein, lactose, and fat content in milk of cows suffering from subclinical and clinical mastitis caused by Streptococcus spp.

The aim of the study was to analyse the total protein (TP), casein (CAS), lactose (LAC), and fat content of milk from cows with subclinical (SCM) and clinical mastitis (CM) caused by Streptococcus spp. A total of 60 milk samples from diseased cows and 30 milk samples from healthy cows were included in the study. Milk samples were taken from Holstein-Friesian cows from four dairy farms in Lublin Province. The bacteriological examination of the milk was performed and the somatic cells count in 1 mL of milk was determined using a SomaCount FC automatic cell counter. Determination of TP, CAS, LAC, FAT and FA levels in milk was carried out using a DairySpec FT automated Fourier transform infrared spectrometer. Total protein in milk from HE was significantly higher than in milk from cows with mastitis (4.04% vs 3.57% in milk from SCM cows and 3.7% in milk from CM cows, P = 0.001). The CAS level was 2.73% in milk from CM cows and 2.92% in milk from SCM cows vs 3.30% in milk from HE cows, P = 0.001. The changes in CAS and TP in milk resulted in a significant difference in the CAS/TP ratio (81.7% in milk from HE cows vs 73.8% in milk from CM cows). A decrease in levels was also recorded for LAC (4.8% in milk from HE cows vs 4.51% in milk from SCM cows and 4.01% in milk from CM cows, P = 0.001). The fat level was significantly higher in milk from healthy cows than in milk from cows with mastitis (4.0% vs 2.3% in milk from SCM cows and 1.64% in milk from CM cows, P = 0.001). It should be emphasised that the decrease in the levels of TP, LAC and FAT was significant not only in milk from CM cows but also in milk from SCM cows. This is very unfavourable, because the reduction in the main milk components results in poor quality dairy products and impairs line processes.

Milk Yield and Composition, Technological Properties and Homeostasis Indices at Different Lactation Stages and Parities of Two Polish Dairy Goat Breeds

Abstract The purpose of the research was to determine the effect of breed, lactation number, and lactation stage on milk efficiency and goat milk ingredients, these being indicators of milk technological parameters and homeostasis disturbances. Goat breed and number of lactation affected energy-corrected milk, value-corrected milk yield, fat corrected milk, protein, casein, lactose contents and free fatty acids. Additionally, differences in non-fat solids and urea contents were found between two Polish common dairy breeds White Improved (PWI) and Fawn Improved (PFI) goats. Moreover, parity affected milk yield, its acidity and somatic cell count (SCC). Milk yield and milk components were found to vary according to lactation stage. At the beginning of lactation, milk is richer in ingredients which have effect on cheese and yoghurt production. All the goats undergo similar changes related to the lactation stage that is at the same time and this can affect the yield and quality of the curd. In production focused on liquid milk, the age structure of the herd should be properly managed, as the goats in their third lactation or above have higher milk yields, regardless of breed. For cheese production, the PWI breed would be more suitable than PFI as the PWI goat milk contains less SCC and more components essential for milk processing, including caseins.

Is the temperament of crossbred dairy cows related to milk cortisol and oxytocin concentrations, milk yield, and quality?

Reactive dairy cows are more susceptible to stress, and this may result in negative effects on milk yield and quality. The aims of this study were to investigate the relationships between temperament traits and concentration of milk cortisol and oxytocin, milk yield, milkability, and milk quality in Holstein-Gyr cows. Temperament traits were assessed in 76 Holstein-Gyr cows in the milking parlor (by scoring milking reactivity and recording the numbers of steps and kicks during pre-milking udder preparation and when fitting the milking cluster) and during handling in the corral (by measuring the time to enter in the squeeze chute, ET and flight speed, FS). Milk samples were collected for milk quality (% fat, % protein, % lactose, and somatic cell count, SCC), and milk cortisol and oxytocin. Milk yield, milking time, and average flow were also measured. The calmer cows during milking management (class 'low') produced milk with higher protein (p = 0.028) content and tendencies for lower fat (p = 0.056) and higher lactose (p = 0.055) contents. Regarding the hormones, the most reactive cows (class 'high') in the milking and handling corral produced milk with higher concentrations of cortisol (p<0.001) and oxytocin (p = 0.023). In addition, the temperament of the animals affected some of the productive measures evaluated. Cows with reactive temperament had lower milk flow and longer milking time than the intermediate ones and had higher fat and a tendency for lower protein percentage in milk compared to cows with intermediate temperaments. Calm and intermediate cows in the handling corral produced more milk and presented better milkability parameters, such as a shorter milking time and greater average milk flow. Our results suggest that the cows' behavioral reactivity can be related to the intensity of their response to stress during handling.

Endosymbiotic bacteria from donkeys milk in the inhibition of human pathogens

Donkey milk is known for its beneficial aspects such as low fat and cholesterol, total protein and casein content, high lactose, whey protein, calcium, selenium and vitamin D3 content. It also has nutraceutical and utilitarian properties that can boost invulnerability, regulate digestion and conveniently change gut microbiota. The current study was focused on the effect of probiotic bacterial metabolites from donkey milk against human bacterial pathogens. The effective isolate VITRAAJ14 was found to be non-hemolytic and was tolerant to acid, NaCl and bile salt. Antibacterial activity by cross streak method showed maximum zone of inhibition. Well diffusion method also exhibited effective inhibition against Escherichia coli (MTCC No. 9721), Staphylococcus aureus (MTCC No. 3160) and Salmonella enterica (MTCC No. 8587) with fractions obtained from chloroform: ethyl acetate. The metabolites capable of inhibiting pathogens were identified as oleyl alcohol by Gas chromatography- mass spectrometry (GCMS). Lead compounds detected in GCMS was studied for its functional group by Fourier transform infrared spectroscopy (FTIR), which revealed the presence of alcoholic stretch, carboxylic acid OH stretch, alkene and amide bond. The isolate VITRAAJ14 was identified to be the closest neighbour of Bacillus species (MH100985) by 16S rRNA gene sequencing. To our knowledge, current study is the first-time report on the presence of Bacillus sp. from donkey milk showing antibacterial activity due to its ability to produce oleyl alcohol. Scanning electron microscopic images revealed the presence of rod-shaped morphology of the effective bacterium VITRAAJ14.

Nannochloris sp. Microalgae Strain for Treatment of Dairy Wastewaters.

This paper focuses on a process for dairy wastewater treatment by mixotrophic cultivation of microalgae Nannochloris sp., using cheese whey obtained as a side flow from cheese production as an organic carbon source. The microalgae samples were prepared by adding to the standard growth medium increasing amounts of cheese whey, calculated to ensure a lactose concentration between 0 and 10 g/L. The samples were incubated at a constant temperature of 28 °C and 175 rpm stirring speed for a total time of seven days. Two LED (Light Emitting Diode) illumination schemes were applied in order to assess the effect of this parameter on microalgae development and bioactive compound accumulation: continuous illumination (light stress) versus alternative cycles of 12 h light-12 h dark (day-night cycle). The growth medium was analyzed before and after microalgae cultivation in order to determine the reduction of carbon, nitrogen, and phosphorus. The results obtained for this process, after a seven-day cultivation period, were as follows: reduction of 99-100% of lactose from the growth medium, up to 96% reduction in chemical oxygen demand, up to 91% reduction in nitrogen content, and up to 70% reduction in phosphorus content.

Chronic Stress Decreases Lactation Performance.

The ability to provision offspring with milk is a significant adaptive feature of mammals that allows for considerable maternal regulation of offspring beyond gestation, as milk provides complete nutrition for developing neonates. For mothers, lactation is a period of marked increases in energetic and nutritive demands to support milk synthesis; because of this considerable increase in demand imposed on multiple physiological systems, lactation is particularly susceptible to the effects of chronic stress. Here, we present work that explores the impact of chronic stress during lactation on maternal lactation performance (i.e., milk quality and quantity) and the expression of key milk synthesis genes in mammary tissue using a Sprague-Dawley rat model. We induced chronic stress using a well-established, ethologically relevant novel male intruder paradigm for 10 consecutive days during the postpartum period. We hypothesized that the increased energetic burden of mounting a chronic stress response during lactation would decrease lactation performance. Specifically, we predicted that chronic exposure to this social stressor would decrease either milk quality (i.e., composition of proximate components and energy density) or quantity. We also predicted that changes in proximate composition (i.e., lipid, lactose, and protein concentrations) would be associated with changes in gene expression levels of milk synthesis genes. Our results supported our hypothesis that chronic stress impairs lactation performance. Relative to the controls, chronically stressed rats had lower milk yields. We also found that milk quality was decreased; milk from chronically stressed mothers had lower lipid concentration and lower energy density, though protein and lactose concentrations were not different between treatment groups. Although there was a change in proximate composition, chronic stress did not impact mammary gland expression of key milk synthesis genes. Together, this work demonstrates that exposure to a chronic stressor impacts lactation performance, which in turn has the potential to impact offspring development via maternal effects.

A Review of Genetic and Non-Genetic Parameter Estimates for Milk Composition of Cattle

This review focuses on the genetic and non-genetic parameter estimation for dairy cattle milk composition. Milk is the most widely consumed food in the world, containing proteins, fats, lactose, and various vitamins and minerals. Milk's solids content has a direct impact on both its nutritional and economic value. The milk composition trait performances had obtained in the range from 3.5±0.0038 to 6.1±0.05 for fat percentage, 3.07±0.03 to 4.7±0.09 for protein percentage, 3.3 to 5.52±1.71 for lactose content, 12.16±0.14 to 16.02±0.05 for total solid content and 8.47±0.1 to 9.37±0.24 for the solid not fat content of cow milk, respectively. The composition of cow milk is influenced by breed, animal age and health, lactation phase, nutrition, season, milking method, number of lactations, and individual cows. The heritability of milk composition trait ranged from 0.24 to 0.49±0.03 for fat percentage, 0.28 to 0.53±0.009 for protein percentage, 0.41±0.04 to 0.59 for total solid content and 0.17 to 0.68 for the solid not fat content of cow milk, respectively. The repeatability of fat, protein, total solid and solid not fat percentage of bovine milk ranged between 3.9 to 0.98, 0.4 to 0.99, 0.49 to 0.99 and 0.23 to 0.78, respectively. The genetic and phenotypic correlation between fat and solid not fat of cow milk were weakly positive (0.16±0.15, 0.06 ±0.04), whereas a strong positive relationship was found between protein content and solid not fat of cow milk (0.99±0.05, 0.67±0.03), respectively. Enhancing milk compositional quality through genetic selection based on individual performance is successful.

Formulation and Evaluation of Bi-Layer Tablet of Nebivolol and Nateglinide

In the present work, the Bilayered matrix type tablet were prepared by direct and wet granulation technique, in which immediate release layer ( by direct compression) contains Nebivolol and extended release layer (by wet granulation) contains Nateglinide. All the developed bilayer tablets were evaluated for weight variation, friability, thickness and hardness. The percent deviation from the average weight, friability, thickness and hardness was found to be within the prescribed official limits. Release profile of Nebivolol from formulations indicate that lower MCC (Formulations CF1 and CF3) and lactose (Formulation CF3) content displayed higher release rates as compared to formulation with higher MCC and lactose content (Formulation CF2). Also the concentration of KYRON T-314 is also found to influence the release rate of the drug. It was found that formulation containing the highest concentration of superdisintegrants (Formulation CF3) has grater release then other subsequent formulations (Formulations CF1 and CF3). Similarly, the release profile of Nateglinide from formulations indicate that lower HPMC K15M (Formulation CF3) and lactose (Formulation CF3) content displayed higher release rates as compared to formulation with individual HPMC K15M, HPMC K100M, EC (Formulations CF1 and CF2) and higher lactose content (Formulations CF1 and CF2).

Comparative Study on Nutritional Characteristics and Volatile Flavor Substances of Yak Milk in Different Regions of Gannan.

This study aimed to investigate the nutritional properties of yak milk in various areas of Gannan. The milk composition analyzer, automatic amino acid analyzer, and flavor analyzer were used to detect the conventional nutrients, amino acids, and volatile flavor substances of 249 yak milks in Meiren grassland, Xiahe grassland, and Maqu grassland (hereinafter referred to as Meiren yak, Xiahe yak, and Maqu yak) in the Gannan area. The results showed that the fat content of Meiren yak milk was significantly higher than that of Maqu yak and Xiahe yak (p < 0.05). The protein content of Meiren yak milk was significantly higher than that of Xiahe yak (p < 0.05), but not significantly different from that of Maqu yak (p > 0.05). The casein content in the milk of Maqu yak was significantly higher than that of Meiren yak and Xiahe yak (p < 0.05). There was no significant difference in the lactose content of yak milk in the three regions (p > 0.05). The content of glutamic acid in the milk of Meiren yak, Xiahe yak, and Maqu yak was noticeably high, which was 1.03 g/100 g, 1.07 g/100 g, and 1.10 g/100 g, respectively. The total amino acid (TAA) content was 4.78 g/100 g, 4.87 g/100 g, and 5.0 g/100 g, respectively. The ratios of essential amino acids (EAA) and total amino acids (TAA) in the milk of Meiren yak, Xiahe yak, and Maqu yak were 42.26%, 41.27%, and 41.39%, respectively, and the ratios of essential amino acids (EAA) and nonessential amino acids (NEAA) were 73.19%, 70.28%, and 70.61%, respectively. In the yak milk samples collected from three different regions, a total of 34 volatile flavor compounds were detected, including 10 aldehydes, five esters, six ketones, four alcohols, two acids, and seven others. The main flavor substances qualitatively obtained from Meiren yak milk were ethyl acetate, n-valeraldehyde, acetic acid, heptanal, and n-hexanal. Xiahe yak milk mainly contains ethyl acetate, isoamyl alcohol, n-valeraldehyde, heptanal, and ethyl butyrate. Maqu yak milk mainly contains ethyl acetate, n-valeraldehyde, isoamyl alcohol, heptanal, ethyl butyrate, and n-hexanal. Principal component analysis showed that the flavor difference between Xiahe yak and Maqu yak was small, while the flavor difference between Xiahe yak, Maqu yak, and Meiren yak was large. The findings of this research can serve as a foundation for the future advancement and application of yak milk.

Effectiveness of a starch thickened infant formula with reduced lactose content, probiotics and prebiotics on quality of life and clinical outcome in infants with regurgitation and/or colic.

Regurgitation and colic are quite common in young infants, leading to a reduced quality of life (QoL) and to parental distress. Their management is challenging and aims to effectively reassure and relieve symptoms. This study aimed to assess the effectiveness over 30 days of a starch thickened formula with a reduced lactose content, Limosilactobacillus reuteri (Lactobacillus reuteri) DSM 17938 and FOS/GOS. A real-world prospective multicenter experimental study was conducted in a before-after design within subject. Full term infants 0-5 months with regurgitation or colic or both symptoms and without intercurrent illness were included after parental informed consent and received the studied formula. The primary endpoint was the improvement in QoL using the QUALIN infant's questionnaire. Secondary endpoints were the symptoms outcome and the formula tolerance. Of the 101 infants included (age: 6.2 ± 4.3 weeks), 33 had regurgitation, 34 colic and 34 had both. At D30, the QoL score was improved in 75% of infants in per protocol analysis (n = 68; +8.2 ± 13.7; p < 0.001), more in those with colic or both symptoms. Meanwhile, in intention to treat analysis (all p < 0.001), the daily number of regurgitations decreased by 61% and the weekly number of days with colic by 63% while the daily cumulative duration of crying decreased by 82 ± 106 mn. These improvements were observed within the first week by 89 and 76% of parents, respectively. The study formula associated with reassurance is shown to be quickly effective in the management of infant's regurgitation or/and colic in routine clinical practice. https://clinicaltrials.gov/, identifier NCT04462640.

A chemical study of yoghurt produced under isostatic pressure during storage

Yoghurt fermented under sub-lethal high pressure (10, 20, 30 and 40 MPa at 43 °C), and afterward placed under refrigeration (4 °C for 23 days) was studied and compared with yoghurt fermented at atmospheric pressure (0.1 MPa). For a deeper analysis, metabolite fingerprinting by nuclear magnetic resonance (NMR), sugars and organic acids assessment by high performance liquid chromatography (HPLC), total fatty acids (TFA) determination and quantification by gas chromatography with a flame ionization detector (GC-FID) were performed. Metabolomic analyses revealed that only 2,3-butanediol, acetoin, diacetyl and formate vary with the increase of pressure and probable relation with pressure influenced diacetyl reductase, acetoin reductase and acetolactate decarboxylase. Yoghurts fermented at 40 MPa had the lowest content in lactose (39.7 % of total sugar reduction) and the less content in TFA (56.1 %). Further research is of interest to understand more about fermentation processes under sub-lethal high pressure.

Evaluation of 3 northwest European seaweed species on enteric methane production and lactational performance of Holstein-Friesian dairy cows

Seaweeds have been studied for their ability to reduce enteric methane emissions of ruminants when fed as a feed supplement. In vivo research with dairy cattle is mainly limited to the seaweed species Ascophyllum nodosum and Asparagopsis taxiformis, whereas in vitro gas production research covers a broader range of brown, red, and green seaweed species from different regions. The objective of the present study was to determine the effect of Chondrus crispus (Rhodophyta), Saccharina latissima (Phaeophyta), and Fucus serratus (Phaeophyta), 3 common northwest European seaweeds, on enteric methane production and lactational performance of dairy cattle. Sixty-four Holstein-Friesian dairy cattle (16 primiparous, 48 multiparous) averaging (mean ± standard deviation) 91 ± 22.6 d in milk and 35.4 ± 8.13 kg/d fat- and protein-corrected milk yield (FPCM) were randomly assigned to 1 of 4 treatments in a randomized complete block design. Cows were fed a partial mixed ration [54.2% grass silage, 20.8% corn silage, and 25.0% concentrate; dry matter (DM) basis] with additional concentrate bait in the milking parlor and the GreenFeed system (C-Lock Inc.). The 4 treatments consisted of a control diet without seaweed supplement (CON), or CON supplemented with 150 g/d (fresh weight of dried seaweed) of either C. crispus (CC), S. latissima (SL), or a 50/50 mix (DM basis) of F. serratus and S. latissima. Milk yield (28.7 vs. 27.5 kg/d, respectively), fat- and protein-corrected milk (FPCM) yield (31.4 vs. 30.2 kg/d, respectively), milk lactose content (4.57 vs. 4.52%, respectively), and lactose yield (1,308 vs. 1,246 g/d, respectively) increased for SL compared with CON. Milk protein content was lower for SL compared with the other treatments. Milk fat and protein contents; yields of fat, protein, lactose, and FPCM; feed efficiency; milk nitrogen efficiency; and somatic cell count did not differ between CON and the other treatments. Depending on week of experiment, milk urea content was higher for SL compared with CON and CC. No effects were observed of the treatments compared with CON for DM intake, number of visits to the GreenFeed, or gas emission (production, yield, or intensity) of CO2, CH4, and H2. In conclusion, the seaweeds evaluated did not decrease enteric CH4 emissions and did not negatively affect feed intake and lactational performance of dairy cattle. Milk yield, FPCM yield, milk lactose content, and lactose yield increased, and milk protein content decreased, with S. latissima.

Taurine alleviates heat stress-induced mammary inflammation and impairment of mammary epithelial integrity via the ERK1/2-MLCK signaling pathway

Heat stress leads to milk production losses and mammary gland inflammation, which may be associated with mammary epithelium damage. Taurine is one of the most abundant free amino acids in mammals which has anti-inflammatory properties. This study aimed to explore the effect of taurine pretreatment on heat stress-induced mammary epithelial integrity disruption and inflammatory damage. In our first experiment on dairy cows our results showed that compared with animals under autumn thermoneutral condition (THI = 62.99 ± 0.71), summer heat stress (THI = 78.01 ± 0.39) significantly reduced milk yield and disrupted mammary epithelial integrity as revealed by increased concentrations of serotonin and lactose in plasma, and increased levels of SA and Na+/K+ in milk. In our second study, 36 lactating mice were randomly divided into three groups (n = 12) for a 9d experiment using a climate chamber to establish a heat stress model. Our findings suggest taurine pretreatment could attenuate heat stress-induced mammary histopathological impairment, inflammation response, and enhance mammary epithelium integrity, which was mainly achieved by promoting the secretion of ZO-1, Occludin, and Claudin-3 through inhibiting activation of the ERK1/2-MLCK signaling pathway in the mammary gland. Overall, our findings indicated that heat stress induced mammary epithelium dysfunction in dairy cows, and emphasized the protective effect of taurine on mammary health under heat stress conditions using a mouse model, which may be achieved by alleviating the mammary epithelium integrity damage and inflammation response.

IDENTYFIKACJA POLIMORFIZMÓW POJEDYNCZEGO NUKLEOTYDU W OBR ˛EBIE GENÓW KODUJ ˛ACYCH BAKTENCYN ˛E-5 I BAKTENCYN ˛E-7 W POWI ˛AZANIU Z CECHAMI PRODUKCJI MLEKA

Bactencins belong to the bovine cathelicidin family of proteins, and their role in the body is significant. The study analyzed the relationship between polymorphisms within the CATHL2 and CATHL3 genes encoding the Bac-5 and Bac-7 proteins. The study included a herd of Polish Holstein-Friesian cows of the black-and-white breed. Tests were conducted using the PCR-RFLP method with the introduction of the ACRS modification. The study showed that different genetic variants within the polymorphisms studied were significantly associated with selected parameters of milk performance, such as milk yield (P ≤ 0.01), fat (P ≤ 0.01), protein (P ≤ 0.01 and P ≤ 0.05) and lactose (P ≤ 0.01 and P ≤ 0.05) content and somatic cell count (P ≤ 0.01 and P ≤ 0.05).

Unveiling the attributes of rabbit milk

Increasing the knowledge of rabbit milk can help in breeding practice to solve issues considering the health and growth of rabbit kits. The goal of the study was to perform a broad physicochemical analysis of rabbit milk and examine the effect of the reproductive status of the females on daily milk yield and milk attributes. The study was conducted on a commercial rabbit farm and included three consecutive lactations of Hycole does. It has been observed that the daily milk production increased from the 2nd till the 14th day of lactation when does produced almost 300 g of milk daily. The day of lactation caused a significant variation in the content of total solids, solids-not-fat, total protein, casein, lactose, C18: 2, C18: 3, Somatic Cell Count, and pH. The percentage of fat globules categorised according to their diameter changed with the ongoing lactation as well, and the diameter increased from 5 to 7 µm. The percentage of small milk fat globules decreased with lactation day, causing a possible decrease in the digestions rates of milk. Pregnancy had a negative impact on milk production, kits growth performance, and the content of total protein, solids-not-fat, and lactose in milk. Therefore, we can speculate about the negative impact of overlapping lactations and pregnancies on rabbit kits, as their growth is dependent on milk production and composition.

Hydration dominates dielectric spectroscopy-based high accuracy quantification of lactose content in cow's milk.

Lactose is a critical factor in the quality of milk and dairy products. Achieving high accuracy and rapid detection of lactose content in cow's milk remains a challenge. Dielectric spectroscopy has emerged as a promising tool for detecting food components. We explored the effect of lactose content on the dielectric spectra of cow's milk and proposed a rapid analytical method for the quantitative determination of lactose content in cow's milk with high accuracy based on dielectric spectra. We obtained the dielectric spectra of 316 cow's milk samples in the frequency range of 20 to 4500 MHz and noticed a strong negative correlation between the lactose content and the value of the dielectric loss factor (ε'') below 1500 MHz. Lactose doesn't affect cow's milk dielectric properties by excluded volume effect but dominates the effect on the dielectric properties of cow's milk by hydration. The support vector regression (SVR) model based on the variable importance in projection (VIP) has the best prediction performance for lactose content. Its root-mean-square error of prediction set (RMSEP) and residual prediction deviation (RPD) is 0.29 g kg-1 and 6.968, respectively, and its prediction performance is better than that of the currently reported near-infrared (NIR) method and other methods. Despite the weak polarity of lactose molecules, its hydration is a significant factor affecting the dielectric properties of milk. This study provides a basis for high accuracy and rapid quantitative detection of lactose in cow's milk based on dielectric spectra. This article is protected by copyright. All rights reserved.

Evaluating the effects of different processing methods on the nutritional quality of bovine milk

Milk is a universal food that is widely consumed around the world irrespective of age. It has a complex matrix consisting of proteins, carbohydrates, minerals, vitamins, and enzymes that have successfully retained the interest of researchers as yet. The aim of the study was to evaluate the effect of low-temperature long-time (LTLT), ultraviolet light (UV), and ultrasound (US) treatments on physicochemical properties, microbial count, and fatty acid profiling of three types of bovine milk – Country (C), Jersey (J), and Holstein Friesian (HF). The study was conducted in southern India, where these three types of milk are commonly consumed. It was found that no significant (p ˂ 0.05) differences in the proximate composition of milk samples subjected to different treatments compared to untreated milk. However, LTLT treatment resulted in a reduction in ascorbic acid content and significant changes in antioxidant activity and lactose content. LTLT treatment was also able to kill the pathogenic bacteria E. coli, whereas UV and US treatment only showed a notable reduction in the E. coli count. Fatty acid profiling of the treated milk samples was done using GC/MS, and Fourier Transform Infrared Spectroscopy (FTIR) was performed to study the types of chemical bonds present. The results showed that non-thermal treatments (UV and US) were able to sustain the chemical characteristics of milk and had potential for implementation in the dairy industry. Overall, the study highlights the potential benefits of non-thermal treatments such as UV and US in maintaining the chemical properties of milk and reducing pathogenic bacteria count. The findings could be useful in the dairy industry to ensure the safety and quality of milk.