Milk Test Research Articles

Physicochemical characteristics of kefir milk from lotus (Nelumbo nucifera) seed milk

This study aims to determine the physicochemical characteristics of milk kefir from lotus seed milk (Nelumbo nucifera) and to determine the effect of increasing the concentration of lotus seed milk (Nelumbo nucifera) on physical and chemical properties. physical composition which includes lightness, chroma and hue color tests as well as viscosity and chemical composition which includes moisture, ash, fat, protein and carbohydrate content as well as to determine the best treatment for the manufacture of kefir milk. The research method used was a randomized block design (RDB) with treatment with different concentrations of lotus seed milk with 5 levels of treatment, namely A0 (100% cow's milk, 0% lotus seed milk), A1 (75% cow's milk, 25% lotus seed milk), A2 (cow's milk 50% lotus seed milk 50%), A3 (cow's milk 25% lotus seed milk 75%), A4 (0% cow's milk 100% lotus seed milk) and was repeated 2 times. The results showed that the lightness and chroma color test of kefir milk with lotus seed milk concentration treatment decreased but the hue color and viscosity of kefir milk increased. The ash, fat, protein and carbohydrate content values of milk kefir with lotus seed milk concentration treatment decreased, but the water content value increased.

Photoelectrochemical sensor for the detection of Escherichia coli O157:H7 based on TPA-NO2 and dual-functional polythiophene films

The detection of Escherichia coli (E. coli) is of great significance for the environment and human health. Herein, a photoelectrochemical (PEC) detection strategy based on molecularly imprinted polymers (MIPs) was proposed for the sensitive detection of E. coli. 4,4′,4″-Trinitrotriphenylamine (TPA-NO2) was prepared using a simple nitration reaction. Subsequently, MIP films were polymerized on the surface of TPA-NO2 using 1,3-dihydrothieno[3,2-d]pyrimidine-2,4-dione as the functional monomer with the dual functions of specific recognition and sensitization. The linear range was 10–108 CFU/mL and the limit of detection was 10 CFU/mL. It showed favorable recoveries in real sample tests of milk, orange juice and tomato. Additionally, the ability of functional monomers to bind excellently with E. coli was verified using molecular docking techniques. This research provided broader possibilities for constructing MIPs-PEC sensors and analyzing the interaction mechanism between E. coli and functional monomers.

Maternal care in wild toque macaques (Macaca sinica) involves prolonged lactation and interbirth intervals as adaptations to reduce maternal depletion and infant mortality in harsh environments.

Weaning age in primates has been challenging to measure and new methods, involving molecular biomarkers in feces, tissue, or teeth have contributed to a solution. Here, we used a direct approach by briefly anesthetizing 442 female toque macaques (Macaca sinica) of Sri Lanka (over a 17-year period) and manually testing their mammary tissue for the presence or absence of milk. Milk tests were related to known offspring ages and maternal care behaviors and indicated that older infants suckled milk well past the weaning age of 7 months that is often reported for food-provisioned primates. Mothers strongly rejected their infants' nursing attempts in two phases, the first at 7 months as an honest signal "giving notice" promoting a shift to greater independence from milk to solid food, and when "shutting down" at final weaning after 12-18 months. The shift to supplementary lactation coincided also with the cessation of mothers carrying their infants and a resumption of cycling. All infants up to 7.2 months suckled milk, 91% of them did up to 18 months, this continued for 42% of infants beyond 18 months, and normally none received milk after 22 months. Lactation extended into 2.2% of cycling and 10.7% of pregnant females (up to 50% of gestation). The interbirth interval was prolonged by factors predicted to draw on female metabolic energy reserves and included the duration of lactation, growth among primiparas, and dietary limitations. The last also increased menarche. Females offset the metabolic costs of lactation with increased foraging and catabolism, but infants died when lactation costs seemingly compromised maternal condition. The prolonged lactation and slowed reproduction are considered adaptations to promote infant survival and growth in an environment where the natural food supply limits population growth and competition for food and water impacts the mortality of the youngest the most.

Understanding Knowledge and Attitude of Farmers towards Antibiotic Use and Antimicrobial Resistance in Jhunjhunu District, Rajasthan India.

The misuse of antibiotics in veterinary practices by farmers is harming livestock production and food safety and leading to the rise of antibiotic resistance (AMR). This can also transfer resistant bacteria from animals to humans, posing a serious public health threat. However, we have not paid enough attention to understanding how farmers behave in this regard. Our study aims to explore farmers' behaviors and identify the factors that influence their choices. To conduct this study, we used a questionnaire with 40 questions and surveyed 208 farmers in Jhunjhunu district, Rajasthan. We analyzed the data using SPSS. Here are the key findings: About 58.3% of the farmers have some awareness of antibiotics, and 49.5% are aware of antimicrobial resistance (AMR). Notably, as the level of education increases, so does awareness of antibiotics. Unfortunately, 63.9% of the farmers are not aware of the withdrawal time, and 64% have no idea about the presence of antibiotic residues during this period. Around 75% of farmers vaccinate their animals, but approximately 56.9% of individuals have never undergone an antibiotic sensitivity test (ABST) for milk. Around 48.6% of farmers are unaware of government testing centers. Several factors hinder farmers from implementing proper animal management practices, such as the high fees of veterinarians. When their animals become sick, their first choice is home remedies, followed by using old prescriptions. Additionally, 63.9% stop treatment once the animal looks better. A significant portion (83.8%) of farmers rely on local pharmacists for medicine. It has been determined that there is no significant correlation between education, experience, age, and the level of awareness concerning withdrawal periods, the existence of government antibiotic sensitivity test (ABST) centers, and entities responsible for sending samples for ABST. In our qualitative analysis, focus groups identified significant barriers to following best farm practices and spreading awareness about AMR. These findings suggest that addressing AMR in livestock requires a comprehensive approach. This should include targeted education and awareness programs for farmers, as well as improved access to veterinary services.

Utilization of kepok banana flour and tempeh flour in making flakes

Utilization of banana flour in making flakes is one of the efforts to diversify flakes products. Flakes made from kepok banana flour have a high carbohydrate but low protein content. According to SNI, the minimum requirement for protein in cereal products is 5%, so to meet the protein content in flakes, it needs to be combined with other ingredients, such as tempeh flour. The use of tempe flour in making flakes made from kepok banana flour is expected to increase the protein content of flakes. This research aimed to determine and obtain the best ratio between kepok banana flour and tempeh flour for making flakes. This research used a completely randomized design with four treatments and four replications. The treatments in this research were the difference in the ratio between kepok banana flour and tempeh flour, namely PT0 (kepok banana flour 100%), PT1 (90:10), PT2 (80:20), and PT3 (70:30). Data were analyzed using variance analysis and then continued with Duncan's New Multiple Range Test at 5% level. The result showed that the ratio of kepok banana flour and tempeh flour significantly affected moisture, ash, fat, protein, crude fiber, carbohydrate contents, crispy resistance in milk, and descriptive and hedonic sensory test. The best ratio of kepok banana flour and tempeh flour was 70:30, respectively. It had 1.77% moisture, 3.39% ash, 11.40% fat, 9,23% protein, 5.52% crude fiber, 74.22% carbohydrate, and crispy resistance in milk 7,61 minutes with a description of light brown, banana and tempeh flavored, crunchy texture, and banana and tempeh taste. Panelists preferred a hedonic assessment of color, aroma, taste, and overall assessment, and panelists preferred the crunchy texture

Detection of Clostridium perfringens in donor milk at a human breast milk bank: a case report

BackgroundThe breast milk bank is a professional organization that collects donor human milk (DHM) for special medical needs by recruiting qualified breast milk donors. Such organizations are also responsible for the disinfection, processing, testing, storage, distribution, and use of breast milk. As DHM is a biological product, it may get contaminated. Microbiological testing is the final step to determine microbial contamination of DHM. However, a universal method for the microbiological analysis of DHM in breast milk banks globally is lacking.DHM without strict screening may become a potential carrier of pathogens and seriously threaten the health of infants. Clostridium perfringens, a gram-positive anaerobic bacterium, is capable of causing wound infections, including gas gangrene, enteritis/enterocolitis, and enterotoxemia. Here, the first case of C. perfringens detected in DHM has been reported to facilitate the identification of such contamination in breast milk banks.Case presentationA breastfeeding mother donated 3000 mL of milk to the breast milk bank of the First Affiliated Hospital of the Army Medical University(over 2900 beds and patient receiving capacity of over 132,000), Chongqing, China. The milk sample was subjected to microbiological screening using liquid enrichment, followed by anaerobic and aerobic culturing. The results revealed the growth of C. perfringens in the anaerobic culture medium, but no bacteria or yeast-like fungi were observed in the aerobic culture medium. The donor did not exhibit any clinical symptoms, and her routine blood results and body temperature were normal. However, the infant fed with her milk had recurrent bloody stools. Breast milk bank infection control emergency handling as well as environmental sampling and investigation revealed that the cause was contamination of the donor’s home-use breast pump with C. perfringens. The infant no longer experienced bloody stool once the donor changed the breast pump.ConclusionsC. perfringens can enter breast milk from contaminated pumping environments or devices, thus causing illness in infants. The microbiological testing of DHM in breast milk banks can be accomplished using liquid enrichment, along with anaerobic and aerobic culture, which is of immense significance in improving the standards for microbiological screening, DHM safety, and infant health.

Microbiological Screening of Donor Human Milk.

Mother's own milk is recognized as the optimal feeding not only for term but also for preterm infants. In addition to risk reduction for sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and retinopathy of prematurity in the early infancy, feeding preterm infants with mother's own milk is also associated with a better neurodevelopmental outcome; lower rates of otitis media, gastroenteritis, and respiratory infections; and a reduced risk of cardiovascular disease, obesity, and diabetes later in life. Donor human milk is the best alternative if mother's own milk is not available or with short supply. There is growing evidence that the benefits of human milk are mediated by the human milk microbiota and by human milk oligosaccharides through their influence on the infant's gut microbiota. Unfortunately, although human milk contains beneficial bacteria, it may also contain pathogenic bacteria. The antimicrobial properties of human milk protect those infants fed with their own mother's raw milk. In donor human milk, however, the antimicrobial activity is diminished due to storage and in particular by pasteurization, hereby lowering the resistance against bacterial infections. Subsequently, microbiological screening of donor human milk might enhance its safety for preterm infants. Up to date, a consensus on recommendations for the microbiological testing of donor human milk is lacking. Existing local and national guidelines for the microbiological screening vary significantly in terms of timing and frequency of testing as well as their specific acceptance and discard criteria. We reviewed the literature about microbiological testing of donor human milk to provide evidence-based recommendations for donor human milk.

Milk as a diagnostic fluid to monitor viral diseases in dairy cattle.

Infectious viral diseases in dairy cattle have substantial implications for milk production, quality and overall animal health. Diagnostic tools providing reliable results are crucial for effective disease control at the farm and industry level. Pooled or bulk tank milk (BTM) can be used as a cost-effective aggregate sample to assess herd disease status in dairy farms. Detection of pathogens or specific antibodies in milk can be used for monitoring endemic diseases within-farm, region or country-level disease surveillance and to make informed decisions on farm management. The suitability of assays applied to pooled milk samples relies on validation data of fit-for-purpose tests to design an optimal testing strategy. Diverse approaches and variable scope of studies determining test accuracy need to be critically appraised before sourcing the parameters to design sampling strategies and interpreting surveys. Determining if BTM or pooled milk is the best approach for a disease management programme should carefully consider several aspects that will impact the accuracy and interpretation, for example, the size of the lactating herd, the risk of infection in the lactating and non-lactating groups, the expected within-herd prevalence, the duration of infection, the duration and concentration of antibodies in milk and use of vaccination. There are examples of tests on BTM samples providing efficient assessments of the herd disease status and supporting disease control programmes for viral diseases. However, challenges arise in pooled milk testing due to the need for accurate estimates of the imperfect sensitivity and specificity of the assays. Integration of new biotechnologies could enhance multiplexing and data interpretation for comprehensive surveillance. The development of highly sensitive assays is necessary to meet the demands of larger dairy herds and improve disease detection and assessment.

Milk as an indicator of dietary imbalance.

Milk provides a readily available diagnostic fluid collected daily or more frequently on an individual animal or herd basis. Milk, as an aggregated sample in bulk tank milk (BTM) represents the status of a herd instead of a single animal. In this review, we examine the potential for milk to predict risks to efficient production, reproductive success, and health on the individual cow and herd level. For many conditions related to disorders of metabolism including hyperlipdaemia and ketonaemia, improved individual cow milk testing may allow a temporally useful detection of metabolic disorder that can target intervention. However, the extension of these tests to the BTM is made more difficult by the tight temporal clustering of disorder to early lactation and the consequent mixing of cows at even moderately different stages of lactation. Integrating herd recording demographic information with Fourier-transformed mid-infrared spectra (FT-MIR) can provide tests that are useful to identify cows with metabolic disorders. The interpretation of BTM urea and protein content provides useful indications of herd nutrition. These may provide indicators that encourage further investigations of nutritional influences on herd fertility but are unlikely to provide strong diagnostic value. The fat-to-protein ratio has a high specificity, but poor sensitivity for detection of fibre insufficiency and acidosis on an individual cow basis. Selenium, zinc, β-carotene, and vitamin E status of the herd can be determined using BTM. There appears to be increasing potential for the use of milk as a diagnostic fluid as more in-parlour tests become available for individual cows. However, the BTM appears to have under-utilised potential for herd monitoring.

Associations of cow- and herd-level factors during the dry period with indicators of udder health in early-lactation cows milked by automated milking systems

This observational study aimed to determine the association of cow-level factors and herd-level housing and management practices during the dry period with indicators of udder health in early-lactation cows in automated milking system (AMS) herds. Data were collected from 166 commercial AMS dairy farms (mean ± standard deviation = 116 ± 111 milking cows; range = 39 to 1,200) across Canada between October 2018 and September 2020. Information on herd demographics, housing, and management practices was obtained on each farm using 2 surveys. On each farm, we selected all cows that had available Dairy Herd Improvement (DHI) somatic cell count (SCC) data for their last milk test before dry-off (>250 d in milk) and their first milk test after calving (5-45 d in milk). Data from 14,007 cows were included after excluding cows with a dry period of <30 d and >120 d. Using the SCC data, we calculated for each cow the somatic cell score (SCS) for the last milk test before dry-off (PreSCS) and the first milk test after calving (PostSCS), which we then averaged per herd at a test-day level. Intramammary infection (IMI) was estimated using cow SCC data. Each cow was classified as not infected (SCC <200,000 cells/mL) or infected (SCC ≥200,000 cells/mL) at her last milk test before dry-off and her first milk test after calving. Based on this classification, cows were further categorized as never infected, always infected, new IMI, or cured IMI. At the cow level, a higher PostSCS was associated with longer dry periods. The odds of having a new IMI were higher for cows of higher parity and that had lower 305-d milk yield before dry-off. Cows with lower parity were more likely to cure an IMI. At the herd level, a higher 305-d milk yield before dry-off was associated with a lower incidence of new IMI and a higher incidence of cured IMI. Separating cows into a different pen as preparation for dry-off tended to be associated with a lower PostSCS and incidence of new IMI. At dry-off, herds that used teat sealants and blanket antibiotic dry cow therapy also had lower PostSCS. During the dry period, housing cows in different groups was associated with a higher PostSCS and a lower incidence of cured IMI, while housing cows in both pack pens and stalls compared with only pack pens was associated with a lower incidence of new IMI. Finally, placing cows onto the AMS to be milked one or more days after calving tended to be associated with a lower PostSCS compared with placing them in the AMS within the first day postpartum. In summary, indicators of udder health in early-lactation cows in AMS herds were associated with several cow-level factors and herd-level housing and management practices before dry-off, at dry-off, during the dry period, and at the beginning of lactation. Thus, if some of the associations identified are causal, AMS producers may be able to improve udder health through modifications of housing and management practices.

Mid-infrared spectroscopy for large-scale phenotyping of bovine colostrum gross composition and immunoglobulin concentration

Immunoglobulin G is the fundamental antibody for acquisition of passive transfer of immunity in ruminant newborns. Colostrum, in fact, must be administered as soon as possible after birth to ensure a successful transfer of IgG from the dam to the calf. Assessment of colostrum Ig concentration and gross composition via gold standards is expensive, time consuming, and hardly implementable for large-scale investigations. Therefore, in the present study we evaluated the predictive ability of mid-infrared spectroscopy (MIRS) as an indirect determination method. A total of 714 colostrum samples collected within 6 h from parturition from Italian Holstein cows, 30% primiparous and 70% pluriparous, were scanned using a benchtop spectrometer after dilution in pure water. The prediction models were developed by correlating spectral information with the reference measurements: IgG concentration (93.54 ± 33.87 g/L), total Ig concentrations (102.82 ± 35.04 g/L), and content of protein (14.71 ± 3.51%), fat (4.61 ± 3.04%), and lactose (2.36 ± 0.51 mg/100 mg). We found a good to excellent performance in prediction of colostrum IgG concentration and traditional composition traits in cross-validation (R2CV ≥ 0.92) and a promising and good predictive ability in external validation with R2V equal to 0.84, 0.89, and 0.74 for IgG, protein, and fat, respectively. In the case of IgG and protein content, for example, the coefficient of determination in external validation was greater than 0.84. The other Ig fractions, A and M, presented insufficient prediction accuracy likely due to their extremely low concentration compared with IgG (4.56 and 5.06 g/L vs. 93.54 g/L). The discriminant ability of MIRS-predicted IgG and protein content was outstanding when trying to classify samples according to the quality level (i.e., low vs. high concentration of IgG). In particular, the cut-off that better discriminate low- from high-quality colostrum was 75.40 g/L in the case of the MIRS-predicted IgG and 13.32% for the MIRS-predicted protein content. Therefore, MIRS is proposed as a rapid and cheap tool for large-scale punctual IgG, protein, and lactose quantification and for the screening of low-quality samples. From a practical perspective, there is the possibility to install colostrum models in the MIRS benchtop machineries already present in laboratories in charge of official milk testing. Colostrum phenotypes collected on an individual basis will be useful to breeders for the definition of specific selection strategies and to farmers for management scopes. Finally, our findings may be relevant for other stakeholders, given the fact that colostrum is an emerging ingredient for the animal and human food and pharmaceutical industry.

Associations between Johne’s disease and fertility in UK dairy herds

The objective of this observational study was to quantify associations between Mycobacterium avium subspecies paratuberculosis (MAP) antibody status and a variety of fertility outcomes, in UK dairy cattle. Longitudinal milk recording, fertility and MAP antibody enzyme-linked immunosorbent assay (ELISA) milk test data were collated retrospectively from 121,762 lactations in 78 herds. Datasets were structured into appropriate units to suit outcomes and enable temporal association between current and future MAP status, and fertility measures. Current MAP status was categorised according to most recent status within 180 days, with time-related future MAP status assigned based on MAP antibody ELISA milk test data for each cow. Multilevel multivariable logistic regression models were used to evaluate associations between MAP status and 21-day pregnancy and submission rate and conception risk. Posterior predictions and cross-validation techniques were used to assess model fit and check model building assumptions. A negative association was found between risk of insemination (Odds Ratio [OR], 0.78; 95% Credible Interval [CI], 0.66–0.92) and conception occurring (OR, 0.65; CI, 0.5–0.84) and transition from negative to non-negative MAP test status in the next 30–90 days. A positive association was observed between risk of insemination (OR, 1.34; CI, 1.16–1.52) and conception occurring (OR, 1.26; CI, 1.11–1.43) and transition from negative to non-negative MAP test status in the next 90–180 days. Current positive MAP test status was negatively and positively associated with insemination (OR, 0.59; CI, 0.49–0.70) and conception risk (OR, 1.12; CI, 0.96–1.30), respectively. Herd managers will have had access to test results, declaring cows with past recent or multiple positive MAP antibody ELISA results not to be bred, negatively influencing insemination risk. Overall, these results demonstrate the temporal association between a positive MAP antibody ELISA result and dairy cow fertility outcomes, with particular variability prior to a positive MAP antibody ELISA result.

Comparative Analysis of Methods for Somatic Cell Counting in Cow's Milk and Relationship between Somatic Cell Count and Occurrence of Intramammary Bacteria.

The aim of this study was to compare three on-farm commercial methods for the indirect detection of subclinical mastitis in dairy cows: the California mastitis test (CMT), the Porta side somatic cell count milk test (Porta SCC), and the DeLaval cell counter (DCC), with the Fossomatic cell count (FSCC), and to evaluate the relationship between the determined somatic cell count SCC and the occurrence of intramammary pathogens in the milk of dairy cows. A total of 284 sensory unchanged mixed milk samples, collected during the milking on a dairy farm, were analyzed in this study for somatic cell counts by the mentioned on-farm tests. Quarter milk samples (n = 583) from all the selected cows were cultured. The agreement, sensitivity, and specificity of the three indirect commercial diagnostic tests (the CMT, the Porta SCC, and the DeLaval cell counter) were calculated, and the FSCC was used as the gold standard. The results were analyzed statistically using the Pearson correlation test and the paired t-test. The CMT matched with the FSCC in 83.1% of the samples, with the Porta SCC in 80.6%, and with the DCC in 80.3% of the samples. The sensitivity and specificity reached 81.0% and 92.9% for the CMT, 79.4% and 90.7% for the Porta SCC, and 75.8% and 97.5% for the DCC, respectively. The correlation between the FSCC and the Porta SCC was 0.86 (p < 0.0001), and between the FSCC and the DCC, it was 0.92 (p < 0.0001). The differences between them were insignificant. Bacteria were detected in 130 (22.3%) quarter milk samples. The most prevalent bacteria were Enterococcus spp. (36.2%), followed by E. coli (20%), coagulase-negative staphylococci (13.1%), A. viridans (9.2%), Streptococcus spp. (9.2%), Proteus spp. (6.2%), and S. intermedius (3.9%). Contagious isolates (S. aureus) were detected in 3 quarter milk samples (2.3%). The agreement between the individual tests and the microbiological culture was as follows: 69.2% for the CMT; 73.7% for the Porta SCC; 71.6% for the DCC; and 76.5% for the FSCC. Higher SCCs were detected in the milk samples contaminated with bacteria than in the healthy milk (p < 0.001). No significance was found between the presence of individual species of intramammary pathogens and the different levels of SCCs. Based on the results, bacteria are the predominant cause of subclinical mastitis. The increased SCC of some milk samples with no presence of bacteria meant that the increase could have been caused by numerous other agents (viruses, fungi, or algae) or factors for mastitis in the dairy industry.

Mastitis prevention and control: Integration of microbiological and management approaches

Mastitis is a common cause of reduced dairy productivity in cows and poor milk quality. This paper considers a set of approaches based on microbiological studies and risk analysis aimed at reducing the number of cows with mastitis and improving milk quality. The study is aimed at examining microbial agents isolated from the milk of sick cows and means of ensuring udder health, and identifying the main dangers that arise due to errors in the implementation of mastitis prevention measures. The study included microbiological tests of milk, wipes and udder dipping using chromogenic media. For a qualitative risk assessment, a survey of consulting managers and veterinarians was conducted. The paper presents the results of microbiological tests of 115 samples of milk, 45 reusable napkins, and 111 samples of udder dips using conventional and chromogenic media. The most common microorganisms in milk samples were Streptococcus spp. 34.4% (S. agalactiae and S. disgalactiae), Staphylococcus aureus 31.1%, and Escherichia coli 28.9%. Staphylococcus aureus and Streptococcus spp. it is associated with infectious mastitis, and Escherichia coli – with sanitary mastitis. To reduce the incidence of mastitis, it is important to apply targeted measures aimed at various categories of pathogens. Udder wipes were contaminated with pathogens associated with the development of mastitis. The use of laundry detergent containing bactericidal components is crucial to minimise contamination of reusable udder wipes. Among the dips under study, 40.6% of the samples had a complete bactericidal effect, and 9.9% had no bactericidal effect. 3 factors of high risk of environmental mastitis and 6 factors of sanitary mastitis were identified. The results of the studies were tested on two dairy farms. Correction of high-risk risk factors led to an increase in the quality of milk in terms of somatic cells and the number of bacteria. The results obtained can be useful for improving the system of prevention and optimisation of mastitis treatment on dairy farms

Assessment of the biological value of forages according to the control tests of milk and its use in the organization of feeding of dairy cattle

The article presents the results of the assessment of the biological usefulness of feed according to the control tests of milk. Scientific research was carried out in LLC "Minskoye" of the Kostroma district of the Kostroma region on a population of 369 cows of the Kostroma and Black-and-White breeds according to the seasons of the year. The authors found that in terms of the level of digestible protein in lactating cows, there is an imbalance in almost all seasons of the year, so most animals are prone to diseases associated with metabolic disorders. The level of rumen acidity in animals of the Koroma breed was more stable (pH = 6.2-6.4) in all seasons of the year, which indicates a lower likelihood of developing acidosis, in contrast to Black-and-White breed cows. Based on the indicators of milk control tests, insufficient supply of raw protein to cows of the Kostroma and Black-and-White breeds during the milking period was established. The highest daily milk yields (more than 30 kg of milk) were obtained from cows in the first and second periods of lactation in all seasons of the year. In animals with a level of availability of digestible protein of 10.3-10.9 g/MJ, there is a normal ratio of fat: protein (1.26:1), with a profitability level of 66.11%, while animals with an insufficient level availability of digestible protein of 10.2 g/MJ and less, had the level of profitability of milk production 73.93 and 86.44%, respectively. When the level of availability of digestible protein is more than 11.0 g/MJ in animals, the likelihood of acidosis increases. Evaluation of the biological value of feeds according to control tests of milk during the period of control milkings will allow monitoring the energy and protein nutrition of animals.

A scoping review of the testing of bulk tank milk to detect nonbacterial pathogens or herd exposure to nonbacterial pathogens in dairy cattle

In this scoping review, we characterized the literature reporting on the testing of bulk milk samples to detect microorganisms other than bacteria that can cause diseases in dairy cattle, including viruses, helminths, algae, and protozoa. A search strategy was completed by screening databases, conference proceedings, animal health agency websites, disease surveillance program websites, and handbooks of cattle-related diagnostic tests for potentially relevant articles. Two reviewers independently screened articles in English, Portuguese, or Spanish; original studies reporting on the testing of farm-level, unprocessed bulk milk samples for presence of pathogens or specific antibodies against agents other than bacteria that can cause diseases in cows were retained. From all studies, we used spreadsheets to extract relevant information, including pathogen screened, test used, and country of origin of bulk milk samples. Additionally, for studies reporting sufficient data to estimate test characteristics, we extracted detailed information about herd eligibility, testing protocol, and herd-level infection definition. A total of 8,829 records were identified, from which 1,592 were retained and assessed for eligibility, and 306 were included. Bovine viral diarrhea virus, Fasciola hepatica, Ostertagia ostertagi, and bovine herpesvirus 1 were the most frequently screened agents, reported from 107, 45, 45, and 33 studies, respectively. Sensitivity of bulk milk ELISA to detect herds with animals infected by bovine herpesvirus 1 ranged from 2 to 100%, and was affected mostly by antigen selection, cut-off adopted, herd vaccination status, and seroprevalence of lactating cows. Bulk milk ELISA had very high specificity to detect herds free of bovine leukemia virus, and varying sensitivity to detect herds with infected animals, which depended on the within-herd seroprevalence of lactating cattle. As for bovine viral diarrhea virus, in general, the sensitivity of bulk milk ELISA was moderate to high (>80%) when infection status was defined based on presence of persistently infected cattle or a high proportion of seropositive lactating cattle. Nevertheless, bulk milk ELISA was not able to distinguish infected and noninfected herds based on presence of seropositive unvaccinated weanlings. The PCR or quantitative PCR protocols employed had very low sensitivities (<40%) and very high specificities (>95%) to classify bovine viral diarrhea virus infection status of dairy herds. Sensitivity and specificity of bulk milk ELISA to classify herds with regards to presence of F. hepatica- or O. ostertagi-parasitized cattle were generally high and driven mostly by the definition of herd infection status. Conversely, bulk milk ELISA demonstrated varying characteristics to detect herds with or without Dictyocaulus viviparus-parasitized cattle, depending primarily on the antigen selected and presence of cattle with clinical signs of lungworm infection.

Ultrasensitive visual detection of the food-borne pathogen via MOF encapsulated enzyme

Various methods have been made to achieve sensitive detection (10 CFU/mL) of Escherichia coli O157:H7 (E. coli) in real samples, however, they are complex, time-consuming, or instrument-dependent. Enzyme-catalyzed reactions are one of the most efficient methods to amplify signals for sensitive detection. ZIF-8 owning stability, porosity, and high specific area are suitable for embedding enzymes which can effectively protect enzyme activity and thus improve detection sensitivity. Herein, a simple visual assay of E. coli with the limits of detection of 1 CFU/mL was developed based on this stable enzyme-catalyzed amplified system. A microbial safety test of milk, orange juice, seawater, cosmetic, and hydrolyzed yeast protein, was successfully performed with the limits of detection of 10 CFU/mL by the naked eye. And this bioassay possessed high selectivity and stability making the developed detection method practically promising.

Evaluation and application of a milk antibody ELISA for assessing the prevalence and incidence of bovine tuberculosis in dairy herds in Hubei Province, China

Bovine tuberculosis (bTB) is a chronic zoonotic disease that is endemic in China. Current in-vitro tests for bTB are mainly based on blood assays. Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner. This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples. Totally 4,395 milk samples were used to assesse the apparent (test) prevalence and incidence of bTB using the milk antibody ELISA. The association between levels of bTB milk antibody and milk quality was also evaluated. Milk and serum antibody tests showed a good correlation with a 87.5% (95% CI: 61.7%, 98.4) positive agreement and 98.7% (95% CI: 95.4, 99.8) negative agreement. The animal level lactoprevalence ranged from 0.3% (95% CI: 0, 1.2) to 33.3% (95% CI: 26.6, 40.6) in different farms and the incidence rate ranged from 0 head/cow-month (95% CI: 0, 0.02) to 0.04 head/cow-month (95% CI: 0.02, 0.07). Twenty percent of sampled farms met the criteria for bTB control in China. The prevalence on large-scale farms was lower (p < 0.001) than on small farms. The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count (SCC), milk protein percentage (MPP) and percentage of total solids (TS). According to this research, milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.

Early Milk Total and Differential Cell Counts as a Diagnostic Tool to Improve Antimicrobial Therapy Protocols

Mastitis is a major cause of antimicrobial treatments either during lactation or at drying off. From a One Health perspective, there should be a balance between the risk of IMI that may impair cow health and welfare and the reduction of antimicrobial usage to decrease antimicrobial resistance, as may happen when applying selective dry-cow therapy. This reduction may be achieved by an early and accurate diagnosis followed by prudent and rationale therapeutical protocols. This study aims to assess the accuracy of PLCC (neutrophils + lymphocyte count/mL) in identifying cows at risk of having IMI due to major pathogens (S.aureus, Str.agalactiae, Str.uberis, and Str.dysgalactiae), and to simulate the impact of this early diagnosis on the potential number of treatments using a decision-tree model. The results of this study showed that PLCC had an overall accuracy of 77.6%. The results of the decision-tree model based on data from the 12 participating herds, with an overall prevalence of major pathogens of 1.5%, showed a potential decrease in the number of treatments of about 30% (from 3.4% to 2.5%) when PLCC in early lactation (days 5-16) was used to identify cows at risk for major pathogens compared with using SCC at the first milk test (days 17-43). The study confirmed that it is possible to improve animal health and reduce the risk of antimicrobial use through early IMI detection based on PLCC and applying a rationale and prudent antimicrobial protocol.

Associations of Eliminating Free-Stall Head Lock-Up during Transition Period with Milk Yield, Health, and Reproductive Performance in Multiparous Dairy Cows: A Case Report

The objective of this retrospective case study was to understand the effects of eliminating free-stall lock-up time during 21 days postpartum on milk yield, reproductive performance, and health events at a large dairy herd. A group of 200 cows were selected as the treatment (TRT) group, which did not receive a lock-up time during early lactation, and a separate group of 200 cows served as the control (CON) group, which received on average 2 h/day of lockup time. The TRT group had greater milk yield (mean ± SE) on the third monthly milk test day (33.1 ± 0.75 vs. 29.9 ± 1.22; p = 0.04) and tended to have greater milk yield on the second test day (38.3 ± 1.55 vs. 39.1 ± 0.79; p = 0.06) compared to the CON cows. Milk fat% (mean ± SE) was greater in the TRT group than in the CON group on the first monthly milk test (3.65 ± 0.06 vs. 3.31 ± 0.12, p = 0.01). The TRT group had lower linear somatic cell scores on the first monthly milk test day compared to the CON group (2.6 ± 0.24 vs. 3.2 ± 0.11; p = 0.01). Cows in the TRT group had lower days in milk at first breeding (DIMFB) (66.2 ± 3.7 vs. 76.7 ± 2.9; p = 0.02) and were confirmed pregnant earlier as indicated by smaller days in milk to pregnancy (DIMPREG) (96.9 ± 12.32 vs. 112.1 ± 5.5; p &lt; 0.01). Cows in the TRT group also had fewer incidences of all health events combined (13% vs. 30.5%; p &lt; 0.001), lameness (3% vs. 9.5%; p = 0.01), and mastitis (3% vs. 16%; p &lt; 0.001). We conclude that eliminating the stall lockup may have contributed to the increased milk yield, health, and reproductive performance of dairy cows in this dairy herd. Future prospective cohort studies are needed to further assess the potential effect of eliminating lock up time on cow performance.