Cow's Milk Research Articles

Role of Milk-Derived Antimicrobial Peptides and Their Future Perspectives in Pharmaceutical/ Dairy Industries

Milk is a good source of bioactive peptides of high nutritive/ pharmaceutical value. In recent decades, the curiosity about bioactive milk peptides has been increasing because of their positive impact on physiological and metabolic functions in human health. A variety of naturally acquired bioactive peptides have been found in fermented dairy products like sour milk and cheese. Initially, these bioactive peptides are found as inactive forms within the precursor protein sequence and can be released in different ways. They can be generated by gastrointestinal digestion of milk, fermentation of milk with proteolytic microorganisms, or hydrolysis via proteolytic enzymes. Once they are released from the precursor protein sequence, they influence body functions and human health. Peptides derived from cow milk exert multifunctional properties, including antimi-crobial, antidiabetic, antihypertensive, anti-inflammatory, immune-modulatory, antioxidant activ-ities, etc. Bioactive antimicrobial peptides are observed in the Cow milk proteins. The Cow milk peptides afford the non-immune-based defense and control for various microbial infections. These activities depend upon their amino acid composition/ sequence. Potential pathogens are con-stantly exposed to mucosal surfaces (lungs and small intestine). The risk of chronic disease was inhibited by antimicrobial peptides, which may afford natural immune protection with the avoid-ance of microbial resistance. In this regimen, the present review summarizes the milk-derived an-timicrobial peptides obtained from casein/ whey protein, along with their future perspectives in the pharmaceutical and dairy industries.

Analisis Kandungan Protein pada Susu Sapi Perah Kemasan dari Peternakan Desa Gunung Perak Sinjai Barat

Humans require food and beverages that serve as building materials, regulators, and sources of energy. Protein is an essential component that functions in tissue maintenance, formation of essential body compounds, antibody production, and maintaining bodily balance. However, the protein content in packaged dairy cow milk can decrease over storage time after packaging, which may affect the nutritional value received by consumers. This study aims to identify and analyze changes in protein levels in packaged dairy cow milk over three days after packaging. The research method used is UV-VIS spectrophotometry with a Genesys 10-S spectrophotometer to measure the protein content in dairy cow milk samples taken from Gunung Perak Village, Sinjai Barat Subdistrict, Sinjai Regency. The results showed that the protein content of the milk one day after packaging was 0.027%, two days after packaging was 0.021%, and three days after packaging was 0.019%. This decrease in protein levels indicates that the duration of storage after packaging negatively affects the protein quality of the milk. The implication of these research findings is the need for special attention in the storage and distribution process of packaged dairy cow milk to maintain its protein content, ensuring that the nutritional value received by consumers remains optimal. Further research with different methods is recommended to obtain more in-depth information about the factors influencing changes in protein levels in the milk.

A Cost-Effective and Sensitive Method for the Determination of Lincomycin in Foods of Animal Origin Using High-Performance Liquid Chromatography.

Lincomycin (LIN) is extensively used for treating diseases in livestock and promoting growth in food animal farming, and it is frequently found in both the environment and in food products. Currently, most of the methods for detecting lincomycin either lack sensitivity and precision or require the use of costly equipment such as mass spectrometers. In this study, we developed a reliable high-performance liquid chromatography-ultraviolet detection (HPLC-UVD) method and used it to detect LIN residue in 11 types of matrices (pig liver and muscle; chicken kidney and liver; cow fat, liver and milk; goat muscle, liver and milk; and eggs) for the first time. The tissue homogenates and liquid samples were extracted via liquid-liquid extraction, and subsequently purified and enriched via sorbent and solid phase extraction (SPE). After nitrogen drying, the products were derivatized with p-toluene sulfonyl isocyanic acid (PTSI) (100 µL) for 30 min at room temperature. Finally, the derivatized products were analyzed by HPLC at 227 nm. Under the optimized conditions, the method displayed impressive performance and demonstrated its reliability and practicability, with a limit of detection (LOD) and quantification (LOQ) of LIN in each matrix of 25-40 μg/kg and 40-60 μg/kg, respectively. The recovery ranged from 71.11% to 98.30%. The results showed that this method had great selectivity, high sensitivity, satisfactory recovery and cost-effectiveness-fulfilling the criteria in drug residue and actual detection requirements-and proved to have broad applicability in the field of detecting LIN in animal-derived foods.

Determination of multi-residue pesticides in dairy products using single-step emulsification/demulsification clean-up strategy combined with low-pressure gas chromatography-tandem mass spectrometry

In this study, a simple, sensitive, and rapid method was developed for the simultaneous determination of 99 kinds of pesticides in fatty milk samples. This novel emulsification-demulsification clean-up approach, coupled with an automatic demulsification-dehydration cartridge, allowed rapid single-step clean-up operation and high throughput. It also achieved effective and selective removal of lipids. The analysis was performed using low-pressure gas chromatography-tandem mass spectrometry (LPGC–MS/MS). Based on the optimal conditions, the targeted pesticides showed good linearity in the range of 5–250 μg/kg, with recoveries of 70–120% at spiking levels of 5, 10, and 20 μg/kg in cow milk, goat milk, and almond milk, respectively. The limit of quantification for most pesticides was 5 μg/kg, and the RSDs were lower than 20%. Analysis of real dairy products obtained from local markets revealed a potential risk in plant-derived almond milk, but no significant risks were found for cow and goat milk.

Four novel Acinetobacter lwoffii strains isolated from the milk of cows in China with subclinical mastitis

BackgroundAcinetobacter lwoffii (A. lwoffii) is a Gram-negative bacteria common in the environment, and it is the normal flora in human respiratory and digestive tracts. The bacteria is a zoonotic and opportunistic pathogen that causes various infections, including nosocomial infections. The aim of this study was to identify A. lwoffii strains isolated from bovine milk with subclinical mastitis in China and get a better understanding of its antimicrobial susceptibility and resistance profile. This is the first study to analyze the drug resistance spectrum and corresponding mechanisms of A. lwoffii isolated in raw milk.ResultsFour A. lwoffii strains were isolated by PCR method. Genetic evolution analysis using the neighbor-joining method showed that the four strains had a high homology with Acinetobacter lwoffii. The strains were resistant to several antibiotics and carried 17 drug-resistance genes across them. Specifically, among 23 antibiotics, the strains were completely susceptible to 6 antibiotics, including doxycycline, erythromycin, polymyxin, clindamycin, imipenem, and meropenem. In addition, the strains showed variable resistance patterns. A total of 17 resistance genes, including plasmid-mediated resistance genes, were detected across the four strains. These genes mediated resistance to 5 classes of antimicrobials, including beta-lactam, aminoglycosides, fluoroquinolones, tetracycline, sulfonamides, and chloramphenicol.ConclusionThese findings indicated that multi-drug resistant Acinetobacter lwoffii strains exist in raw milk of bovine with subclinical mastitis. Acinetobacter lwoffii are widespread in natural environmental samples, including water, soil, bathtub, soap box, skin, pharynx, conjunctiva, saliva, gastrointestinal tract, and vaginal secretions. The strains carry resistance genes in mobile genetic elements to enhance the spread of these genes. Therefore, more attention should be paid to epidemiological surveillance and drug resistant A. lwoffii.

Brief communication: New method for measuring nitrogen isotopes in tooth dentine at high temporal resolution.

Nitrogen isotopes (δ15N) are widely used to study human nursing and weaning ages. Conventional methods involve sampling 1-mm thick sections of tooth dentine-producing an averaging effect that integrates months of formation. We introduce a novel protocol for measuring δ15N by multicollector secondary ion mass spectrometry (SIMS). We sampled dentine δ15N on a weekly to monthly basis along the developmental axis in two first molars of healthy children from Australia and New Zealand (n = 217 measurements). Nitrogen isotope ratios were determined from measurements of CN- secondary molecular ions in ~35 μm spots. By relating spot position to enamel formation, we identified prenatal dentine, as well as sampling ages over more than 3 years. We also created calcium-normalized barium and strontium maps with laser ablation-inductively coupled plasma-mass spectrometry. We found rapid postnatal δ15N increases of ~2‰-3‰, during which time the children were exclusively breastfed, followed by declines as the breastfeeding frequency decreased. After weaning, δ15N values remained stable for several months, coinciding with diets that did not include meat or cow's milk; values then varied by ~2‰ starting in the third year of life. Barium did not show an immediate postnatal increase, rising after a few months until ~1-1.5 years of age, and falling until or shortly after the cessation of suckling. Initial strontium trends varied but both individuals peaked months after weaning. Developmentally informed SIMS measurements of δ15N minimize time averaging and can be precisely related to an individual's early dietary history.

Penyuluhan Penetapan Harga Pokok Produksi Barang/Jasa Bagi Anggota AMPI/HKTI Bandung Barat

ABSTRACT The aim of this community service is to provide an understanding of how to determine the basic production price of cow's milk products for dairy farmers in Pengalengan and to provide an understanding of marketing strategies for cow's milk products for dairy farmers in Pengalengan. The method used is interactive where the speaker and participants ask each other questions and answers regarding the counseling given. The result of this community service is that the participants understand how to calculate the cost of production for goods and services sold in the form of cow's milk and agricultural products such as potatoes and vegetables. The implication of this community service is the application of the correct calculation of the cost of production for livestock breeders and farmers in canning so as to produce competitive selling prices.

Identification of the serum metabolites associated with cow milk consumption in Chinese Peri-/Postmenopausal women

Cow milk consumption (CMC) and downstream alterations of serum metabolites are commonly considered important factors regulating human health status. Foods may lead to metabolic changes directly or indirectly through remodelling gut microbiota (GM). We sought to identify the metabolic alterations in Chinese Peri-/Postmenopausal women with habitual CMC and explore if the GM mediates the CMC-metabolite associations. 346 Chinese Peri-/Postmenopausal women participants were recruited in this study. Fixed effects regression and partial least squares discriminant analysis (PLS-DA) were applied to reveal alterations of serum metabolic features in different CMC groups. Spearman correlation coefficient was computed to detect metabolome-metagenome association. 36 CMC-associated metabolites including palmitic acid (FA(16:0)), 7alpha-hydroxy-4-cholesterin-3-one (7alphaC4), citrulline were identified by both fixed effects regression (FDR < 0.05) and PLS-DA (VIP score > 2). Some significant metabolite-GM associations were observed, including FA(16:0) with gut species Bacteroides ovatus, Bacteroides sp.D2. These findings would further prompt our understanding of the effect of cow milk on human health.

Discrimination of cow, goat, and sheep milk by femtosecond and nanosecond laser-induced breakdown spectroscopy

In the present work, femtosecond Laser Induced Breakdown Spectroscopy, fs-LIBS, is applied for the first time for the analysis of the inorganic content and the identification of the animal origin of milk samples (i.e., cow, goat, and sheep). The fs-LIBS spectra were analyzed by different machine learning algorithms (i.e., multivariate statistical analysis), and their performance was assessed. The obtained classification accuracies of the milk samples based on the animal origin were found to attain values up to 95 %, depending on the algorithm used. For comparison purposes, LIBS experiments were also carried out employing nanosecond laser pulses, ns-LIBS. The obtained results from both the fs- and ns-LIBS experiments were found to be in excellent agreement between them. The present findings, using fs laser excitation, demonstrate and extend the capabilities of LIBS technique, for the identification of the animal origin of milk samples, thus making fs- and/or ns-LIBS technique a powerful and useful tool for milk authentication, quality, and safety control related research.

Development and validation of an ELISA kit for the detection of Staphylococcus aureus enterotoxin A, B, C1, C2, C3, D, E from food samples

Staphylococcus aureus (S. aureus) is a significant food-borne pathogen that poses a threat to human health. The classical serotypes staphylococcal enterotoxin (SE) A, B, C1, C2, C3, D, E produced by S. aureus are the primary cause of its food-borne pathogenic toxicity. Therefore, establishing a highly sensitive, rapid, robust, high-throughput detection method for the total amount of classical serotypes of SEs is crucial for food safety and public health. This study prepared 10 rabbit polyclonal antibodies and 40 mouse monoclonal antibodies targeting SEA, SEB, SEC1, SEC2, SEC3. Upon identifying the optimal antibody pairs through square array method and optimization, a sandwich ELISA kit for the detection of SEs (SEA, SEB, SEC1, SEC2, SEC3, SED, SEE) was developed, with respective limits of detection at 0.169–0.688 ng/mL. In addition, this sandwich ELISA kit could detect SEs in raw cow milk, pasteurized milk, fermented milk, milk powder, whey powder, rice, raw pork, and canned beef samples with coefficients of variation below 7%. Meanwhile, this sandwich ELISA kit was stable at 4 °C for one-year storage. The study fills a research gap in the detection of the total amount of classical serotypes of SEs.

An overview of probiotic camel milk as a nutritional beverage: Challenges and perspectives

AbstractThere are challenges such as standardization for commercialization and guaranteeing sensory characteristics in camel milk processing. This review gathers a general view of the probiotic camel milk, its contents, its health aspects, and its industrial production. One of the potential candidates of a healthy food product is “probiotic camel milk” which contains several nutritional elements including Lactic acid bacteria and Bifidobacteria and postbiotics such as endopolysaccharides, exopolysaccharides, numerous beneficial enzymes, short‐chain fatty acids, teichoic acids, peptides, peptidoglycan‐derived neuropeptides, cell surface proteins, different vitamins, plasmalogens, and different kinds of organic acids. It should also be considered that camel milk generally has some advantages over cow milk like its health‐beneficial antidiabetic, hypoallergenic, and anticancer properties. As a result, it is gaining much attention from both consumers and manufacturers, and the global probiotic market trend is growing. Although there are obstacles in standardizing processing techniques and maintaining sensory excellence, the health benefits, economic prospects, and adaptability of camel milk and its probiotic variations create a promising avenue for continued research and advancement. Therefore, developing standardized processing techniques and sensory evaluation methods for probiotic camel milk can unlock its full potential as a nutritious beverage, offering a promising solution for consumers seeking healthy and functional food products.

Increasing the productivity of cows through the use of premixes based on forest and mineral resources in feeding

The influence of premixes based on forest (pine needles, pine nut shells, arabinogalactan) and mineral (bentonite clay, expanded vermiculite) raw materials on dairy productivity of cows has been studied. The experiment was conducted in the Krasnoyarsk region on three groups of Black-and-White breed cows (10 heads per group) at the age of the third calving, with a live weight of 530–550 kg. The control group was fed the basic diet, the 1st experimental group was fed a premix consisting of bentonite clay, pine coniferous flour, pine nut shells, vitamin and mineral complex and arabinogalactan in addition to the basic diet. Cows of the 2nd experimental group were fed a premix of a similar compo sition with the exception of bentonite clay, instead of which expanded vermiculite was included in the premix. The duration of the experiment was 60 days. The cows were kept tethered and walking, milking was automatic in the milk pipeline. The feeding ration corresponded to zootechnical standards. The studied premixes were fed in a mixture with concentrated feeds once a day. The research was carried out according to generally accepted methods using modern certified equipment. Feeding the cows of the studied premixes had a positive effect on milk productivity in both experimental groups, however, the greatest increase in productivity compared with the control was found in cows of the 2nd experimental group who received a premix with expanded vermiculite in the composition. Milk yield of natural fat content in this group increased by 7.60%, milk yield of basic fat content – by 14.02%, the mass fraction of fat in milk – by 0.23 percentage points, the amount of milk fat – by 14.02%, milk protein – by 9.65%. The organoleptic parameters of the milk of experimental cows under the influence of the studied premixes did not deteriorate and met the requirements of the GOST (Russian National Standard) for premium milk.

Heat Stress in Iraq Slashes Dairy Cow Health and Milk Production

This study examined the impact of heat stress on dairy cows in Iraq, categorizing them into Comfortable Zone (CZ), Mild Stress (MS), and High Stress (HS) based on the Thermal Humidity Index (THI). Over 90 days, cows were monitored for physiological, hematological, biochemical, and milk production parameters. Results showed that as heat stress increased, cows exhibited higher respiration, heart, and pulse rates, and rectal and skin temperatures. Hemoglobin and packed cell volume decreased, while red blood cell count and other related measures increased. Biochemical analyses revealed higher levels of cortisol, blood urea nitrogen, total protein, and liver enzymes, with reduced albumin. Milk yield and quality significantly declined under HS conditions. These findings highlight the need for effective heat stress mitigation to protect cow health and dairy productivity in hot climates. Highlights: Heat Stress Impact: Increased respiration, heart, pulse rates, and rectal and skin temperatures. Blood Changes: Lower hemoglobin, higher cortisol, blood urea nitrogen, liver enzymes. Milk Production: Reduced yield, fat content, and protein content under high stress. Keywords: heat stress, dairy cows, physiology, milk production, Iraq

Development a new vegan muffin formulation and evaluation their some quality and sensory characteristics

This study aimed to develop a healthy, vegan muffin that is gluten-free and lactose-free, while maintaining sensory appeal. Black chickpea flour, aquafaba, and almond milk were incorporated into the recipe to achieve this. Various substitutions were tested, including 11.1% (M-1), 16.7% (M-2), and 22.2% (w:w) (M-3) chickpea flour replacements, along with 19.4% almond milk and 11.1% aquafaba, compared to control muffins (M-0) containing wheat flour, cow milk, and chicken egg. Results showed pH values ranging from 6.45 to 6.95 for batter and 6.76 to 7.10 for baked muffins, with dry matter content between 63.71% and 65.54%, and baking loss between 9.76% and 11.81%. Calorie values were highest in M-0 (330.69 kcal/100 g), reduced to 272.83-269.72 kcal/100 g with chickpea flour, aquafaba, and almond milk. Muffin height and volume decreased insignificantly in M-1, M-2, and M-3 compared to reference muffins (p&gt;0.05). The uniformity index, volume, symmetry index, and volume index significantly decreased with chickpea flour addition (p0.05). Overall, this demonstrates the potential to create sensorially pleasing vegan muffins by incorporating ingredients like black chickpea flour, aquafaba, and almond milk.

Infant versus noninfant formulas and cow's milk: Transition based on age or weight?

Infant formulas are meant to be used until 1 year of age, at which point children are transitioned to non-infant formulas or cow's milk, depending on their remaining dietary intake. Noninfant formulas and cow's milk are appropriate for children who have an average weight at that 1-year mark (9-9.5 kg); however, can contribute significant protein and/or electrolytes to children who are underweight for age, particularly if they still rely heavily on formula feeding for their caloric intake. In this short communication, we present several cases of patients who received excessive amounts of nutrients for age following the formula transition at the 1-year mark. We also provide recommendations for clinicians to consider when faced with underweight infants who are meant to be transitioning off infant formulas.

Influence of the season on the main components of cow milk in Ukraine

The quality of dairy products depends on the safety and quality of raw materials, therefore, the analysis of physicochemical and sanitary indicators of raw cow milk is of great importance. The composition of bulk milk of three technological groups of cows: early lactation (5–60 days in milk), primiparous cows and all other cows starting from the second lactation was studied according to seasons. Regardless of the group of animals, the fat content in bulk milk was significantly lower in summer than in other seasons of the year, and the highest in winter. In each group of animals, the lowest somatic cell count was observed in the fall, while the highest indicator of the study of bulk milk of cows in early lactation and primiparous was determined in the winter, and in the spring of cows from the second lactation. The lowest milk urea content in all groups of animals was noted in summer. The lowest protein level was observed in autumn (3.27 ± 0.11%), and the highest in winter (3.39 ± 0.11%) in the bulk milk of cows in early lactation. The ratio of fat to protein in summer 1.12 ± 0.03 was significantly lower compared to other seasons of the year. The highest level of somatic cells was recorded in this group in winter (290 ± 82 * 103 cells/mL), which was twice as much as in autumn (141 ± 54 * 103 cells/mL), and by 56.8% more than in summer (185 ± 39 * 103 cells/mL). The milk urea content in the summer was 194.0 ± 17.6 mg/kg, which is significantly lower than the indicators in other seasons of the year in the group of early lactation. In the summer period, the lowest protein content (3.23 ± 0.06%) in the bulk milk of primiparous cows was observed compared to other seasons of the year. The winter was characterized by the highest level of somatic cell count in milk (221 ± 49 * 103 cells/mL), which was almost twice as high as the autumn period (116 ± 31 * 103 cells/mL). The highest urea content in the milk of primiparous cows was found in autumn (228.6 ± 21.9 mg/kg), which exceeded the summer figure by 14.5%. The lowest protein content (3.29 ± 0.06%) and the highest in winter (3.44 ± 0.09%) was observed in the bulk milk of cows of the second lactation and older. The somatic cell count in milk in autumn (160 ± 69 * 103 cells/mL) was lower than the winter and spring indicators by 37.5% and 49.3%, respectively. The milk urea content in the summer (198 ± 22 mg/kg) was significantly lower than the autumn and winter indicators. In further studies, to improve the sanitary quality of milk, it is planned to use different hygienic means for processing the udder of cows depending on the season.

Crafting Algerian “Jben”: a traditional soft cheese enhanced by locally derived starters

The global dairy industry faces challenges in sourcing cost-effective and suitable lactic starters for traditional cheese production. This study investigates the use of locally selected lactic starters in crafting Algerian Jben cheese, aiming to provide a sustainable alternative to imported starters. Local lactic starters comprising Lactococcus lactis, Leuconostoc mesenteroides, and Enterococcus durans were characterized by their technological properties when applied to cow's milk. The resulting cheese was compared with another cheese produced under similar conditions but using an industrial mesophilic starter, including strains of Lactococcus and Leuconostoc. Physicochemical and microbiological analyses were conducted on both cheeses, followed by sensory evaluations using the triangular and classification tests. Microbiological analyses revealed the absence of pathogenic germs or spores in both types of cheese. However, the cheese made with the industrial starter exceeded the standards for fecal coliforms and total coliforms. Titratable acidity measurements indicated comparable levels in both cheeses. Interestingly, there were no discernible differences in taste or aroma between the two types, with both being well received by tasters. In conclusion, our findings suggest that local lactic starters have the potential to replace the commercial starters currently employed in the Algerian dairy industry.

Prevalence and risk factors for milk allergy overdiagnosis in the BEEP trial cohort.

Cow's milk allergy (CMA) overdiagnosis in young children appears to be increasing and has not been well characterised. We used a clinical trial population to characterise CMA overdiagnosis and identify individual-level and primary care practice-level risk factors. We analysed data from 1394 children born in England in 2014-2016 (BEEP trial, ISRCTN21528841). Participants underwent formal CMA diagnosis at ≤2 years. CMA overdiagnosis was defined in three separate ways: parent-reported milk reaction; primary care record of milk hypersensitivity symptoms; and primary care record of low-allergy formula prescription. CMA was formally diagnosed in 19 (1.4%) participants. CMA overdiagnosis was common: 16.1% had parent-reported cow's milk hypersensitivity, 11.3% primary care recorded milk hypersensitivity and 8.7% had low-allergy formula prescription. Symptoms attributed to cow's milk hypersensitivity in participants without CMA were commonly gastrointestinal and reported from a median age of 49 days. Low-allergy formula prescriptions in participants without CMA lasted a median of 10 months (interquartile range 1, 16); the estimated volume consumed was a median of 272 litres (26, 448). Risk factors for CMA overdiagnosis were high practice-based low-allergy formula prescribing in the previous year and maternal report of antibiotic prescription during pregnancy. Exclusive formula feeding from birth was associated with increased low-allergy formula prescription. There was no evidence that practice prescribing of paediatric adrenaline auto-injectors or anti-reflux medications, or maternal features such as anxiety, age, parity and socioeconomic status were associated with CMA overdiagnosis. CMA overdiagnosis is common in early infancy. Risk factors include high primary care practice-based low-allergy formula prescribing and maternal report of antibiotic prescription during pregnancy.

Mitigating antibiotic misuse in dairy farming systems and milk value chain market: Insights into practices, factors, and farmers education in Nyabihu district, Rwanda

The widespread misuse of antibiotics to combat bacterial infections in dairy farming is a global concern contributing to antimicrobial resistance (AMR). To gain insights within small-scale dairy farming, a study was conducted in Nyabihu district of Rwanda from September 2021 to April 2023 to assess practices and factors associated with antibiotic use, investigate antibiotic residues in cow milk and undertake a comprehensive training program to improve quality milk production. A mixed-methods approach, combining cross-sectional and longitudinal intervention studies, involved 42 regular dairy farmers from both open and zero-grazing systems delivering milk to the Union pour la Promotion des Cooperatives des Eleveurs en Nyabihu (UPROCENYA) milk collection center (MCC). Standardized questionnaires and farm interviews were conducted to assess antibiotic use practices while bulk tank milk samples from the same farmers were collected and tested for antibiotic residues using rapid tests over 16 months (8 months before and 8 months after training).Out of 451 bulk tank milk samples tested, 27 samples (6%) contained antibiotic residues, primarily tetracyclines (55.3%) and beta-lactams (44.7%). Before farmers training, 5182.75 l of milk were rejected monthly due to antibiotic residues. Following training, milk rejections decreased to 3192.75 l per month, reflecting 38.35% monthly decrease. However, no statistically significant difference was found by independent t-test (t = 1.441; p = 0.173) between milk rejected before and after training. 97.6% of interviewed farmers reported using antibiotics within six months preceding data collection, with 71.4% primarily used for disease treatment, notably targeting tick-borne diseases (34.0%). Alarming practices included administering antibiotics without referring samples for laboratory examination (100%), disregarding withdrawal periods (88.1%) and administering antibiotics without a veterinary doctor's prescription (85.7%). Factors contributing to these practices included limited farmer’s knowledge on antibiotics, easy access to antibiotics in local agro-veterinary shops, and insufficient veterinary services. Antibiotic-laden milk was used to feed calves (38.6%), consumed at home (26.5%), and sold (12.0%).The observed misuse of antibiotics and disregard for antibiotic withdrawal periods pose significant threats to both milk quality and human health. The authors recommend that dairy farmers prioritize animal health monitoring, seek veterinary advice for disease prevention and treatment and implement biosecurity measures to prevent diseases and thus reduce antibiotic usage. Collaborative efforts among stakeholders are highly recommended to enhance capacity building for dairy farmers and support research initiatives. Furthermore, it is strongly suggested to strengthen regulations on the prudent use of antibiotics within the Rwandan food production system to curb antimicrobial resistance across both animal and human populations.

Effects of feeding sulfate trace minerals above recommendations on nutrient digestibility, rumen fermentation, lactational performance, and trace mineral excretion in dairy cows

Most trace minerals (TM) are fed above dairy cow requirements in commercial herds but their fate and effects on dairy cows have not been well documented. In this study, we evaluated the effects of feeding short-term sulfate TM above recommendations on apparent total-tract digestibility of nutrients, rumen fermentation characteristics, serum concentrations, milk yield and composition as well as milk, fecal, and urinary TM excretion in mid-lactation dairy cows. Eight multiparous Holstein cows [average body weight: 684 (SD: 29) kg at 82 (SD: 10) days in milk] in a quadruple 2 × 2 crossover design were fed a basal diet, differing in sulfate TM supplement concentrations, to provide either 0.11, 17, and 63 (control; CON) or 0.95, 114, and 123 (high trace minerals; HTM) mg of dietary Co, Mn, and Zn/kg of dry matter, respectively. Each experimental period had a 21-d adaptation to the diet, followed by a 10-d sample collection period. Feed ingredients and total feces and urine were collected during 4 consecutive d and rumen fluid was collected 0, 1, 2, 4, and 6 h relative to feeding. Milk yield was recorded daily and milk samples were collected on 4 consecutive milkings. Ingestion of Co, Mn, and Zn was higher for HTM compared with CON group by 216, 233, and 93%, respectively. Dry matter intake averaged 25.0 (SE = 0.6) kg/d, and apparent total-tract digestibility of major nutrients was similar between treatments. There was no measurable effect of HTM on ruminal pH, major volatile fatty acids, and protozoa counts. Isovalerate molar proportion was 9.4% greater for HTM compared with CON group. Neither milk yield (43.5 kg/d; SE = 0.8) nor milk fat and protein concentrations differed between treatments. Milk urea nitrogen concentration was significantly higher for HTM (11.7 mg/dL) compared with CON group (9.7 mg/dL; SE = 0.7). Fecal excretion of Co, Mn, and Zn increased by 223, 198, and 75%, respectively, for HTM compared with CON group. Urinary excretions of TM were marginal compared with feces, and only urinary Co and Mn were significantly higher for HTM than CON cows as similarly obtained for serum Co and Mn concentrations. Milk TM yields were not modified by treatments. In summary, short-term dietary sulfate TM supply over the recommendation did not improve cow performance but significantly increased fecal TM excretion, which could have impacts on TM accumulation in soils where manure is applied and could potentially result in leaching into nearby watersheds. Further studies are needed to evaluate the impact of high fecal TM excretion on the environment using the One Health approach. Moreover, the impacts of TM oversupply on milk production and cow health should be evaluated by long-term experiments.