Dynamic alterations of flavor, functional nutrients, and microbial community during fermentation of different animal milk kefirs.

Kefir is a traditional dairy beverage, usually made from cow or goat milk fermented with kefir grains, and has many health benefits. To elucidate the fermentation patterns of animal milk kefirs during the fermentation process and find the optimal milk types, cow, camel, goat, and donkey milk were fermented with kefir grains for 0, 1, 3, 5, and 7 days. Volatile and non-volatile metabolites and microbial changes were dynamically monitored. The results showed that volatile flavor substances were massively elevated in four kefirs on days 1-3. Lipids and carbohydrates gradually decreased, while amino acids, small peptides, and tryptophan derivatives accumulated during fermentation in four kefirs. Besides, four kefirs had similar alterations in Lactobacillus and Acetobacter, while some distinctions existed in low-abundance bacteria. Association analysis of microorganisms and volatile and non-volatile metabolites also revealed the underlying fermentation mechanism. This study found that appropriately extending the fermentation time contributed to the accumulation of some functional nutrients. Furthermore, goat and donkey milk could be the better matrices for kefir fermentation.

A2 milk: Bioaccessibility of essential minerals and the release of amino groups under static in vitro digestion conditions.

Alternative milk products such as A2 milk are gaining popular stand within consumer market, for their healthy profile and expected greater digestibility characteristics. However, total mineral content and its bioaccessible profile have lacked in studies through the years, even more because of their relevance in public health. The present study aimed to evaluate the mineral profile of commercial A2 bovine milk (AT) and estimate the bioaccessibility of calcium, phosphorus and magnesium using the INFOGEST protocol. Non-A2 samples (NAT) were evaluated for comparison purpose. The determination of Ca, Mg, Na and K was performed by FAAS and total P was quantified by colorimetric method. Total protein content was determined by Kjeldahl method. Free amino acids were quantified by OPA method along the in vitro digestion stages. Total content of Ca, Na and P exhibited equivalent results between samples, although A2 milk showed elevated levels of total Mg and K in the analyzed batches. AT showed protein content equivalent to NAT. In addition, levels of free NH2 were observed 2 times higher in AT, during the first hour of pancreatic phase in the intestinal digestion. Bioaccessibility of Ca showed equivalent percentages for AT (12-42 %) and NAT (10-39 %). The observed low values were possibly derived from interferences with saturated fatty acids and standardized electrolytes during digestion. Similar amounts of bioaccessible Mg were found for all milk samples (35-97 %), while A2 samples evidenced percentages of bioaccessible P exceeding 60 % across the three batches. Despite the health benefits associated to A2 milk, the study did not evidence clear distinction from non-A2 milk in terms of enhanced essential mineral solubility in digestive tract simulation, considering the association of greater digestibility expected for A2 milk.

Performance and incidence of diarrhea in suckling Jersey calves supplemented with mineral-vitamin complex and Virginiamycin.

The rearing of calves is an essential activity of a dairy system, as it impacts the future production of these animals. This study aims to evaluate the incidence of diarrhea, performance, and blood parameters of suckling calves that received mineral-vitamin supplementation in milk plus virginiamycin that was offered in milk (via the abomasum) or by esophageal tube (via the rumen). Twenty-seven calves were used, from the first week to 60 days of age, submitted to the following treatments: CONTROL, without supplementation; MILK, supplementation of 20 g of a mineral-vitamin complex with 100 mg of virginiamycin, diluted in milk; RUMEN, supplementation of 20 g of a mineral-vitamin complex diluted in milk and 100 mg of virginiamycin in gelatin capsules via an esophageal applicator. MILK and RUMEN calves had lower fecal consistency scoring, fewer days with scores 2 and 3 throughout the experimental period, and lower spending on medication compared to the CONTROL animals. Supplemented calves had higher fat and protein intake and reached feed intake of 600 g earlier than CONTROL animals, but did not differ in performance and hematological parameters. Supplementation with virginiamycin and vitamin-mineral complex for suckling calves reduced the incidence and days of diarrhea, and reduced medication costs, with no difference in performance, but the supplemented animals had higher initial protein and fat intake and reached targeted feed intake earlier to begin the weaning process.

Evaluation of different ratios of neutral detergent-soluble carbohydrate fractions on performance, ingestive behavior, and nitrogen balance in dairy goats.

Cell components soluble in neutral detergent are a diverse group, both compositionally and nutritionally. The present study aimed to evaluate production responses, behavior (eating, ruminating, and idling), and nitrogen balance of dairy goats fed different ratios of neutral detergent-soluble carbohydrate fractions. Five multiparous Alpine does with mean ± SD initial body mass of 49.5 ± 7.9 kg and 60 days of lactation were randomly assigned in a 5 × 5 Latin square design. The treatments were the ratios of starch (starch associated with soluble sugar [StSS]) to neutral detergent-soluble fiber (NDSF) (StSS:NDSF): 0.89, 1.05, 1.24, 1.73, and 2.92. No effect was observed (P > 0.05) of StSS:NDSF on the intakes of neutral detergent fiber (NDF) and NDSC. However, DM intake showed a quadratic behavior (P = 0.049). The ingestive behavior was affected by StSS:NDSF linearly increased (P = 0.002) the feeding efficiency. The increase in StSS:NDSF caused a linear increase in fecal (P = 0.011), urinary (P < 0.001), and milk nitrogen excretion (P = 0.024). The increase in StSS:NDSF affected (P = 0.048) milk yield and net energy lactation (P = 0.036). In conclusion, dairy goats experience reduced dry matter intake and milk yield when subjected to high-NDSC diets, specifically those above 1.24 StSS:NDSF ratio. Elevated NDSC levels in the diets lead to decreased feeding time, whereas rumination remains unaffected. Nitrogen losses in goats increase linearly with high-NDSC diets, and a significant impact on nitrogen balance.

Lipidomic Comparisons of Whole Cream Buttermilk Whey and Cheese Whey Cream Buttermilk of Caprine Milk.

Buttermilk is a potential material for the production of a milk fat globule membrane (MFGM) and can be mainly classified into two types: whole cream buttermilk and cheese whey cream buttermilk (WCB). Due to the high casein micelle content of whole cream buttermilk, the removal of casein micelles to improve the purity of MFGM materials is always required. This study investigated the effects of rennet and acid coagulation on the lipid profile of buttermilk rennet-coagulated whey (BRW) and buttermilk acid-coagulated whey (BAW) and compared them with WCB. BRW has significantly higher phospholipids (PLs) and ganglioside contents than BAW and WCB. The abundance of arachidonic acid (ARA)- and eicosapentaenoic acid (EPA)-structured PLs was higher in WCB, while docosahexaenoic acid (DHA)-structured PLs were higher in BRW, indicating that BRW and WCB intake might have a greater effect on improving cardiovascular conditions and neurodevelopment. WCB and BRW had a higher abundance of plasmanyl PL and plasmalogen PL, respectively. Phosphatidylcholine (PC) (28:1), LPE (20:5), and PC (26:0) are characteristic lipids among BRW, BAW, and WCB, and they can be used to distinguish MFGM-enriched whey from different sources.

Relationship between the components of mare breast milk and foal gut microbiome: shaping gut microbiome development after birth.

The gut microbiota (GM) is essential for mammalian health. Although the association between infant GM and breast milk (BM) composition has been well established in humans, such a relationship has not been investigated in horses. Hence, this study was conducted to analyze the GM formation of foals during lactation and determine the presence of low-molecular-weight metabolites in mares' BM and their role in shaping foals' GM. The fecal and BM samples from six pairs of foals and mares were subjected to 16S ribosomal RNA metagenomic and metabolomic analyses, respectively. The composition of foal GM changed during lactation time; hierarchical cluster analysis divided the fetal GM into three groups corresponding to different time points in foal development. The level of most metabolites in milk decreased over time with increasing milk yield, while threonic acid and ascorbic acid increased. Further analyses revealed gut bacteria that correlated with changes in milk metabolites; for instance, there was a positive correlation between Bacteroidaceae in the foal's gut microbiota and serine/glycine in the mother's milk. These findings help improve the rearing environment of lactating horses and establish artificial feeding methods for foals.

Solid phase extraction technology combined with UPLC-MS/MS: a method for detecting 20 ß-lactamase antibiotics traces in goat's milk.

We develop and validate a method for the rapid determination and identification of 20 ß-lactamase antibiotics traces in goat's milk by combining the solid phase extraction technology with ultra-high performance liquid chromatography-tandem mass spectrometry. Goat milk samples were extracted with acetonitrile twice. The supernatant was then extracted and cleaned by solid-phase extraction using divinylbenzene and N-vinylpyrrolidone copolymer. The method was validated, with limits of quantification (LOQs) of 0.3 µg kg-1, specificities of 1/3 LOQ, linearities (R2) > 0.99, recoveries of 80-110%, repeatabilities <10.0%, and intermediate precisions <10.0%. The developed method was suitable for the routine analysis of ß-lactamase antibiotics residues in goat's milk and was used to test 76 goat milk samples produced in China.

A review on the safety of growth factors commonly used in cultivated meat production.

Growth factors are commonly added to cell culture media in cellular agriculture to mimic the endogenous process of proliferation and differentiation of cells. Many of these growth factors are endogenous to humans and known to be present in the edible tissues and milk of food animals. However, there is little or no information on the use of growth factors intentionally added in food production before the advent of cultivated meat. Ten commonly used growth factors have been reviewed to include information on their mode of action, bioavailability, occurrence in food and food animals, endogenous levels in humans, as well as exposure and toxicological information drawn from relevant animal studies and human clinical trials with a focus on oral exposure. In addition, a comparison of homology of growth factors was done to compare the sequence homology of growth factors from humans and domestic animal species commonly consumed as food, such as bovine, porcine, and poultry. This information has been gathered as the starting point to determine the safety of use of growth factors in cultivated meat meant for human consumption. The change in levels of growth factors measured in human milk and bovine milk after pasteurization and high-temperature treatment is discussed to give an indication of how commercial food processing can affect the levels of growth factors in food. The concept of substantial equivalence is also discussed together with a conservative exposure estimation. More work on how to integrate in silico assessments into the routine safety assessment of growth factors is needed.

Effect of feeding sodium butyrate to beef female cows during pre- and post-partum period on concentrations of glucagon-like peptides in plasma and colostrum.

The objective of this study was to evaluate the effect of feeding beef cows with sodium butyrate during the late pregnancy and early post-partum periods on concentrations of glucagon-like peptide (GLP)-1 and 2 in plasma, colostrum, and transition milk. Twelve Japanese Black female cows were fed concentrate feed without (CON; n = 6) or with (BUTY; n = 6) sodium butyrate supplementation at 1.1% of dietary dry matter from -60 d relative to the expected parturition date to 4 d after parturition. Plasma total cholesterol concentration was higher for the BUTY than for the CON (P = 0.04). In addition, plasma GLP-1 concentration was higher for the BUTY than for the CON at 3 d after calving (P < 0.05). This study showed for the first time that GLP-1 is present in the colostrum of Japanese Black cows at higher concentrations as compared to in plasma (P < 0.01). On the other hand, no treatment effect was observed for concentrations of metabolite and hormone in colostrum and transition milk. In summary, feeding beef cows with sodium butyrate during the late gestation and early post-partum period likely increases plasma GLP-1 concentrations post-partum without affecting the components of colostrum and transition milk.

Microwave Dielectric Response of Bovine Milk as Pregnancy Detection Tool in Dairy Cows.

The most reliable methods for pregnancy diagnosis in dairy herds include rectal palpation, ultrasound examination, and evaluation of plasma progesterone concentrations. However, these methods are expensive, labor-intensive, and invasive. Thus, there is a need to develop a practical, non-invasive, cost-effective method that can be implemented on the farm to detect pregnancy. This study suggests employing microwave dielectric spectroscopy (MDS, 0.5-40 GHz) as a method to evaluate reproduction events in dairy cows. The approach involves the integration of MDS data with information on milk solids to detect pregnancy and identify early embryonic loss in dairy cows. To test the ability to predict pregnancy according to these measurements, milk samples were collected from (i) pregnant and non-pregnant randomly selected cows, (ii) weekly from selected cows (n = 12) before insemination until a positive pregnancy test, and (iii) daily from selected cows (n = 10) prior to insemination until a positive pregnancy test. The results indicated that the dielectric strength of Δε and the relaxation time, τ, exhibited reduced variability in the case of a positive pregnancy diagnosis. Using principal component analysis (PCA), a clear distinction between pregnancy and nonpregnancy status was observed, with improved differentiation upon a higher sampling frequency. Additionally, a neural network machine learning technique was employed to develop a prediction algorithm with an accuracy of 73%. These findings demonstrate that MDS can be used to detect changes in milk upon pregnancy. The developed machine learning provides a broad classification that could be further enhanced with additional data.

From bowls to pots: The dairying revolution in Northwest Turkey, a view from Barcin Höyük, 6600 to 6000 BCE.

Research has identified Northwest Turkey as a key region for the development of dairying in the seventh millennium BCE, yet little is known about how this practice began or evolved there. This research studies Barcin Höyük, a site located in Bursa's Yenisehir Valley, which ranges chronologically from 6600 BCE, when the first evidence of settled life appears in the Marmara Region, to 6000 BCE, when Neolithic habitation at the site ceases. Using pottery sherds diagnostic by vessel category and type, this paper aims at identifying which ones may have been primarily used to store, process, or consume dairy products. Organic residue analysis of selected samples helped address the process of adoption and intensification of milk processing in this region over time. The lipid residue data discussed in this paper derive from 143 isotopic results subsampled from 173 organic residues obtained from 805 Neolithic potsherds and suggest that bowls and four-lugged pots may have been preferred containers for processing milk. The discovery of abundant milk residues even among the earliest ceramics indicates that the pioneer farmers arrived in the region already with the knowhow of dairying and milk processing. In fact, these skills and the reliance on secondary products may have given them one of the necessary tools to successfully venture into the unfarmed lands of Northwest Anatolia in the first place.

Gold nanoparticles-doped MXene heterostructure for ultrasensitive electrochemical detection of fumonisin B1 and ampicillin.

Early transition metal carbides (MXene) hybridized by precious metals open a door for innovative electrochemical biosensing device design. Herein, we present a facile one-pot synthesis of gold nanoparticles (AuNPs)-doped two-dimensional (2D) titanium carbide MXene nanoflakes (Ti3C2Tx/Au). Ti3C2Tx MXene exhibits high electrical conductivity and yields synergistic signal amplification in conjunction with AuNPs leading to excellent electrochemical performance. Thus Ti3C2Tx/Au hybrid nanostructure can be used as an electrode platform for the electrochemical analysis of various targets. We used screen-printed electrodes modified with the Ti3C2Tx/Au electrode and functionalized with different biorecognition elements to detect and quantify an antibiotic, ampicillin (AMP), and a mycotoxin, fumonisin B1 (FB1). The ultralow limits of detection of 2.284 pM and 1.617 pg.mL-1, which we achieved respectively for AMP and FB1 are far lower than their corresponding maximum residue limits of 2.8 nM in milk and 2 to 4 mg kg-1 in corn products for human consumption set by the United States Food and Drug Administration. Additionally, the linear range of detection and quantification of AMP and FB1 were, respectively, 10 pM to 500 nM and 10 pg mL-1 to 1 µg mL-1. The unique structure and excellent electrochemical performance of Ti3C2Tx/Au nanocomposite suggest that it is highly suitable for anchoring biorecognition entities such as antibodies and oligonucleotides for monitoring various deleterious contaminants in agri-food products.

ELISA assay for the quantification of ipilimumab in human serum, plasma, milk, and cerebrospinal fluid.

Ipilimumab is an immune checkpoint inhibitor of the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Ipilimumab has become part of the standard of care for different types of cancer. The efficacy of these treatments is limited due to immune-related toxicity and high economic costs. Dose rationalization studies based on pharmacokinetic data may help to address these limitations. For this purpose, more sensitive analytical methods are needed. We report the development and validation of the first enzyme-linked immunosorbent assay (ELISA) for sensitive determination of ipilimumab concentrations in human serum, plasma, cerebrospinal fluid (CSF), and milk. Our assay is based on the specific capture of ipilimumab by immobilized CTLA-4. The lower limit of quantifications of ipilimumab in serum, plasma, and milk are 50 ng/mL and 10 ng/mL in CSF. The ELISA method showed long-term storage stability for at least one year at -80°C and was successfully cross-validated with ultraperformance liquid chromatography coupled with tandem mass spectrometry. The ELISA method is reliable, relatively inexpensive, and can be used in serum, plasma, CSF, and milk from patients treated with ipilimumab, as evidenced by the analysis of real clinical samples.

Double-Tube Multiplex TaqMan Real-Time PCR for the Detection of Eight Animal-Derived Dairy Ingredients.

Milk and dairy products represent important sources of nutrition in our daily lives. The identification of species within dairy products holds importance for monitoring food adulteration and ensuring traceability. This study presented a method that integrated double-tube and duplex real-time polymerase chain reaction (PCR) with multiplex TaqMan probes to enable the high-throughput detection of animal-derived ingredients in milk and dairy products. The detection system utilized one pair of universal primers, two pairs of specific primers, and eight animal-derived specific probes for cow, buffalo, goat, sheep, camel, yak, horse, and donkey. These components were optimized within a double-tube and four-probe PCR multiplex system. The developed double-tube detection system could simultaneously identify the above eight targets with a detection limit of 10-0.1 pg/µL. Validation using simulated adulterated milk samples demonstrated a detection limit of 0.1%. The primary advantage of this method lies in the simplification of the multiplex quantitative real-time PCR (qPCR) system through the use of universal primers. This method provides an efficient approach for detecting ingredients in dairy products, providing powerful technical support for market supervision.

Methionine and Leucine Promote mTOR Gene Transcription and Milk Synthesis in Mammary Epithelial Cells through the eEF1Bα-UBR5-ARID1A Signaling.

Amino acids are essential for the activation of the mechanistic target of rapamycin (mTOR), but the corresponding molecular mechanism is not yet fully understood. We previously found that Met stimulated eukaryotic elongation factor α (eEF1Bα) nuclear localization in bovine mammary epithelial cells (MECs). Herein, we explored the role and molecular mechanism of eEF1Bα in methionine (Met)- and leucine (Leu)-stimulated mTOR gene transcription and milk synthesis in MECs. eEF1Bα knockdown decreased milk protein and fat synthesis, cell proliferation, and mTOR mRNA expression and phosphorylation, whereas eEF1Bα overexpression had the opposite effects. QE-MS analysis detected that eEF1Bα was phosphorylated at Ser106 in the nucleus and Met and Leu stimulated p-eEF1Bα nuclear localization. eEF1Bα knockdown abrogated the stimulation of Met and Leu by mTOR mRNA expression and phosphorylation, and this regulatory role was dependent on its phosphorylation. Akt knockdown blocked the stimulation of Met and Leu by eEF1Bα and p-eEF1Bα expression. ChIP-PCR detected that p-eEF1Bα bound only to the -548 to -793 nt site in the mTOR promoter, and ChIP-qPCR further detected that Met and Leu stimulated this binding. eEF1Bα mediated Met and Leu' stimulation on mTOR mRNA expression and phosphorylation through inducing AT-rich interaction domain 1A (ARID1A) ubiquitination degradation, and this process depended on eEF1Bα phosphorylation. p-eEF1Bα interacted with ARID1A and ubiquitin protein ligase E3 module N-recognition 5 (UBR5), and UBR5 knockdown rescued the decrease of the ARID1A protein level by eEF1Bα overexpression. Both eEF1Bα and p-eEF1Bα were highly expressed in mouse mammary gland tissues during the lactating period. In summary, we reveal that Met and Leu stimulate mTOR transcriptional activation and milk protein and fat synthesis in MECs through eEF1Bα-UBR5-ARID1A signaling.

BCM-7: Opioid-like Peptide with Potential Role in Disease Mechanisms.

Bovine milk is an essential supplement due to its rich energy- and nutrient-rich qualities. Caseins constitute the vast majority of the proteins in milk. Among these, ß-casein comprises around 37% of all caseins, and it is an important type of casein with several different variants. The A1 and A2 variants of ß-casein are the most researched genotypes due to the changes in their composition. It is accepted that the A2 variant is ancestral, while a point mutation in the 67th amino acid created the A1 variant. The digestion derived of both A1 and A2 milk is BCM-7. Digestion of A2 milk in the human intestine also forms BCM-9 peptide molecule. The opioid-like characteristics of BCM-7 are highlighted for their potential triggering effect on several diseases. Most research has been focused on gastrointestinal-related diseases; however other metabolic and nervous system-based diseases are also potentially triggered. By manipulating the mechanisms of these diseases, BCM-7 can induce certain situations, such as conformational changes, reduction in protein activity, and the creation of undesired activity in the biological system. Furthermore, the genotype of casein can also play a role in bone health, such as altering fracture rates, and calcium contents can change the characteristics of dietary products. The context between opioid molecules and BCM-7 points to a potential triggering mechanism for the central nervous system and other metabolic diseases discussed.

Composition and fatty acid profile of milk from cows fed diets supplemented with raw and n-3 PUFA-enriched fish oil.

Dietary supplementation of ruminants with fish oil is a strategy for favorably modifying the fatty acid composition of milk fat. This study investigated the effect of supplementing cows' diet with fish oil after low-temperature crystallisation (LTC-FO) compared to its raw form (FO) on milk yield, milk components (fat, protein, and lactose), and milk fatty acid profile. Twenty-four mid-lactating multiparous Polish Holstein-Friesian cows fed a total-mix ration were randomly assigned to two homogeneous groups (n = 12 cows each) and supplemented with LTC-FO or FO at 1% of dry matter. Milk samples were collected on days 14 and 30 of the 30-day experiment. No significant differences between the groups in terms of milk yield, milk protein, and lactose content were found, however, the fat yield and content decreased in the LTC-FO group. Milk fat from cows in the LTC-FO group contained significantly higher levels of C18:1 trans-11, C18:2 cis-9, trans-11, C18:3n - 3, C20:5, and C22:6, and lower levels of saturated fatty acids compared to the FO group (p < 0.05). Therefore, LTC-FO may be a more efficient feed additive than FO and may serve as a practical way to modify the fatty acid composition of milk fat.

The impact of heat-set milk protein gel textures modified by pH on circulating amino acid appearance and gastric function in healthy female adults: a randomised controlled trial.

Modification of dairy proteins during processing impacts structural assemblies, influencing textural and nutritional properties of dairy products, and release and availability of amino acids during digestion. By modifying only pH, acid heat-set bovine dairy gels with divergent textural properties were developed to alter protein digestion. In vitro assay confirmed faster digestion of protein from a firm gel (pH 5.65) versus a soft gel (pH 6.55). We hypothesised that firm gel (FIRM-G; pH 5.6) would result in greater indispensable amino acid (IAA) appearance in circulation over 5 h and corresponding differences in gastric myoelectrical activity relative to soft gel (SOFT-G; pH 6.2). In a randomised, single-blind cross-over trial, healthy females (n = 20) consumed 150 g of each gel; plasma amino acid appearance was assessed over 5 hours. Iso-nitrogenous, iso-caloric gels were prepared from identical mixtures of bovine milk and whey protein concentrates; providing 17.7 g (FIRM-G) and 18.9 g (SOFT-G) of protein per serving. Secondary outcomes included gastric myoelectrical activity measured by body surface gastric mapping, glycaemic, triglyceridaemic, and subjective appetite and digestive responses. Overall plasma IAA (area under the curve) did not differ between gels. However, plasma IAA concentrations were higher, and increased more rapidly over time after SOFT-G compared with FIRM-G (1455 ± 53 versus 1350 ± 62 µmol L-1 at 30 min, p = 0.024). Similarly, total, branched-chain and dispensable amino acids were higher at 30 min with SOFT-G than FIRM-G (total: 3939 ± 97 versus 3702 ± 127 µmol L-1, p = 0.014; branched-chain: 677 ± 30 versus 619 ± 34 µmol L-1, p = 0.047; dispensable: 2334 ± 53 versus 2210 ± 76 µmol L-1, p = 0.032). All other measured parameters were similar between gels. Peak postprandial aminoacidaemia was higher and faster following ingestion of SOFT-G. Customised plasma amino acid appearance from dairy is achievable by altering gel coagulum structure using pH during processing and may have minimal influence on related postprandial responses, with implications for targeting food design for optimal health. The Clinical Trial Registry number is ACTRN12622001418763 (https://www.anzctr.org.au) registered November 7, 2022.

NAGase sensing in 3% milk: FET-based specific and label-free sensing in ultra-small samples of high ionic strength and high concentration of non-specific proteins.

Biosensing with biological field-effect transistors (bioFETs) is a promising technology toward specific, label-free, and multiplexed sensing in ultra-small samples. The current study employs the field-effect meta-nano-channel biosensor (MNC biosensor) for the detection of the enzyme N-acetyl-beta-D-glucosaminidase (NAGase), a biomarker for milk cow infections. The measurements are performed in a 0.5 µL drops of 3% commercial milk spiked with NAGase concentrations in the range of 30.3 aM-3.03 µM (Note that there is no background NAGase concentration in commercial milk). Specific and label-free sensing of NAGase is demonstrated with a limit-of-detection of 30.3 aM, a dynamic range of 11 orders of magnitude and with excellent linearity and sensitivity. Additional two important research outcomes are reported. First, the ionic strength of the examined milk is ∼120 mM which implies a bulk Debye screening length <1 nm. Conventionally, a 1 nm Debye length excludes the possibility of sensing with a recognition layer composed of surface bound anti-NAGase antibodies with a size of ∼10 nm. This apparent contradiction is removed considering the ample literature reporting antibody adsorption in a predominantly surface tilted configuration (side-on, flat-on, etc.). Secondly, milk contains a non-specific background protein concentration of 33 mg/ml, in addition to considerable amounts of micron-size heterogeneous fat structures. The reported sensing was performed without the customarily exercised surface blocking and without washing of the non-specific signal. This suggests that the role of non-specific adsorption to the BioFET sensing signal needs to be further evaluated. Control measurements are reported.

Effect of exogenous oestrogen treatment frequency on induction of artificial lactation in pseudopregnant sows.

In this study, we examined whether the frequency of exogenous oestrogen treatment affects the induction of artificial lactation and milk production. Furthermore, we analysed changes in milk components obtained from artificially lactating sows. Pseudopregnant induced by treatment with 30 mg of estradiol dipropionate (EDP) on Day 10 (Day 0 = the last day of estrus) were divided into three groups: those administered 5 mg of EDP once on Day 39 (n = 5), twice on Days 32 and 39 (n = 5) and three times on Days 25, 32 and 39 (n = 6). All animals were treated with prostaglandin F2α (PGF2α) on Day 46 for induced lactation. Artificial lactation was induced in 66.7%-80.0% of sows, and the EDP treatment frequency before PGF2α administration had no significant effect on either the induction rate of artificial lactation or the milk yield during the experimental period. The milk composition (levels of crude protein, crude fat, crude ash, lactose and immunoglobulin) did not differ among the groups. In conclusion, the number of EDP treatments prior to PGF2α administration had no effect on either the efficiency of artificial lactation induction or milk production.