Dairy, Volume 5, Issue 1 (March 2024) – 19 articles

The periparturient period, which spans late pregnancy to early lactation in dairy cows, is a crucial phase characterized by complex metabolic and endocrine adjustments necessary for sustained milk production. This research focused on the relationship between serum vaspin, inflammatory cytokines (IL-1, TNF), and markers of negative energy balance (NEB) in 100 primiparous and multiparous Holstein dairy cows. The results demonstrated that one month post-calving, both groups had a significant decrease in serum vaspin levels but increased NEFA levels, indicating possible consequences for lipid metabolism and energy balance. Multiparous cows showed significant elevations in cholesterol, IL-1, and TNF concentrations after calving, indicating increased inflammatory responses. Primiparous cows, on the other hand, responded differently, indicating the role of parity in metabolic adjustments. The study acknowledges limitations such as sample size and its observational nature. Future research should investigate the long-term effects of these metabolic changes on herd health and lactational performance, using advanced technologies to gain a molecular understanding. Despite limitations, this study provides valuable insights into how adipokines, inflammatory markers, and energy balance interact during the periparturient period, offering the potential for improved dairy cow management and productivity while ensuring animal welfare. Full article

The aim of the present research was to study the influence of the calving season in conditions of the upcoming climate changes on the productive traits of dairy cows in Bulgaria. The study was conducted on a cattle farm with a capacity of 500 dairy cows, which were loose-housed in open free-stall barns (shed-type). In the research, 286 lactations of 199 Holstein cattle from the studied farm were included. The cows with the highest average milk yield for lactation—8522.2 kg—calved in the spring, while the cows with the lowest milk yield—8082.7 kg—calved in the summer. Cows that calved in the spring had the highest maximum daily milk yield (lactation peak)—38 kg—whereas cows that calved in the summer had the lowest—35.7 kg. Regarding the composition indicators of milk, fat, and protein content, no significant effect of the calving season was found, but there was a tendency for the lowest values for the percentage of fat in milk to be reported for cows that calved in the summer—3.68%—and the highest for those calved in the spring—3.71%. Regarding the percentage of protein in the milk, the lowest values were observed for cows that calved in autumn—3.19%—and the highest for cows that calved in summer—3.27%. Full article

The dairy industry’s contribution to global warming has been thoroughly examined. However, it is important to raise public awareness of emission hotspots and the possibility of mitigation in dairy supply chains. This study assessed the Carbon Footprint (CF) of five dairy products through a cradle-to-grave Life Cycle Assessment approach and evaluated the carbon sink potential of some practices. The functional units were 1 kg of fresh raw milk, yogurt, fresh cheese, mozzarella cheese, and aged cheese. The data collected were related to an extensive dairy farm, a cheese-factory, two markets, a delivery service, and a court of consumers. The CFs were 4.39, 5.10, 9.82, 8.40, and 15.34 kg CO₂ eq. for fresh raw milk, yogurt, mozzarella cheese, fresh cheese, and aged cheese, respectively. The hotspots of the dairy supply chain considered herein refer to farm activities and energy consumption, whereas conservative agriculture practices and rotational grazing sequestered 1.60 ± 0.80 kg CO₂ eq. per kg of dairy product consumed. The CF was reduced by 0.14 kg CO₂ eq. for 1 kg of dairy product delivered at home compared to direct purchasing at a market. The carbon sink capacity of dairy farms appeared as a primary mean for mitigating climate change in the dairy supply chain. Full article

Dairy cow longevity is associated with three key areas: animal welfare, the economy, and the environment. In pastoral dairy systems, cows are exposed to environmental hardships and variations in feed supply associated with the seasonal growth of pastures. The objectives of this study were to generate base parameters for longevity and evaluate the effect of season and decade of birth on herd life (HL) and length of productive life (LPL) for dairy cows in pasture-based production. Records from the Dairy Herd Improvement Database at the Instituto Nacional para el Control y Mejoramiento Lechero (Uruguay) were extracted. The dataset contained 313,146 cows born between 1 January 2000 and 31 December 2019, classified by decade and season of birth. HL and LPL were calculated for each cow. The effects of season of birth, decade of birth, and the interaction between them on HL and LPL were evaluated using a generalized mixed model. The mean HL was 73.4 and mean LPL was 42.0 months. Cows born in spring had longer LPL and HL (p < 0.001). Cows born in the 2010s had significantly shorter HL (12.8 months) and LPL (9.14 months) (p < 0.001). In conclusion, the season and decade of birth have an impact on the longevity of cows in pastoral-based systems. This study is the first to demonstrate the effect of season of birth on long-term longevity. Full article

Bovine colostrum is the first mammary secretion after parturition; it is rich in Igs and bioactive compounds and could play a role in the development of naturally based products with positive effects on human health. In this discussion, we critically examine the effect of bovine colostrum on the properties of mesenchymal stem cells. Multipotent mesenchymal stem cells (MSCs) are a heterogeneous subset of fibroblast-like cells that can be isolated from various biological tissues, such as bone marrow, umbilical cord, and adipose tissues. They are characterized by their ability to self-renew and differentiate into cells of the mesodermal lineage, including adipocytes, osteocytes, and chondrocytes. Additionally, MSCs display an immunomodulatory capacity due to their ability to interact with effector cells typical of both innate and adaptive immune responses. Considering these important properties, MSCs have gained increasing attention in the field of regenerative medicine in recent decades. To date, most experimental protocols are based on cell culture media supplemented with fetal bovine serum (FBS) to promote the ex vivo expansion of MSCs while preserving their differentiative and immunomodulatory capacities. Future trends could involve the application of bovine colostrum in regenerative medicine. Full article

Background: The UK dairy sheep industry is relatively small but growing, particularly for cheese and yogurt products. Anecdotally, sheep milk (SM) may be better tolerated by humans than cows’ milk and could have environmental as well as health benefits. All milk contains sub-micron particles called extracellular vesicles (EVs) which are mainly derived from the mammary epithelium. Physiologically, milk-derived EVs are thought to aid in the development of infant immunity and the microbiome, but may also have health benefits to adult humans. The purpose of this study was to determine whether EVs could be isolated from raw sheep milk and whether they have any effect on inflammatory responses in THP-1, a human monocyte cell line, in vitro. Methods: Using sequential ultracentrifugation, vesicles of <1 µm (LEV) followed by <200 nm (sEVs) were isolated from six individual sheep during mid-lactation. RNA was extracted and microRNA analyzed by RTqPCR for sequences previously identified in cows’ milk. Human THP-1 monocytes were differentiated into macrophages and incubated with SM-derived LEVs and sEVs in the presence of pro-inflammatory LPS to measure the effects on the secretion of the chemokine CCL-2 or in the presence of DMNQ and fluorescent dihydrorhodamine-1,2,3 to measure reactive oxygen species. Results: LEVs induced an increase in ROS in both monocytes and macrophages, whilst sEVs decreased DMNQ-mediated ROS in macrophages but not monocytes. Interestingly, the LEVs did not induce CCL2 release; however, they increased LPS-induced CCL2 secretion in monocytes but not macrophages. miR26a, miR92a, miR125b, miR155 and miR223 were identified in both sEVs and LEVs by RT-qPCR and could be responsible for the modulation of ROS and CCL2 expression. Conclusions: These findings suggest that like cows’ milk, sheep milk contains EVs, and they can influence human monocyte/macrophage responses, and so is worthy of further investigation for its potential human- and non-human-animal health benefits. Full article

Crossbreeding in dairy cattle with exotic breeds continues to be an appealing practice to the dairy farmers of Bangladesh. However, there is limited knowledge regarding the impact of crossbreeding on both the physical attributes and milk quality traits of crossbred cattle in Bangladesh. Therefore, the primary objective of this study was to evaluate the impact of crossbreeding Bangladeshi local cattle with the exotic Holstein breed on their body characteristics and milk quality. To achieve the goal, data pertaining to body traits and milk samples were gathered from a total of 981 cows from 19 dairy farms located in the northwestern region of Bangladesh. A trained evaluator measured body condition score (BCS), udder score, locomotion score, and body conformation traits. Milk yield information was acquired from official records, while milk composition details were determined through milk analysis. Notably, crossbred cows (Holstein × Local cattle) exhibited greater values for wither height (141 vs. 135, cm), body length (157 vs. 153, cm), heart girth (211 vs. 204, cm), BCS (3.69 vs. 3.27), and udder score (3.29 vs. 2.08) than their Bangladeshi local counterparts. Furthermore, crossbred cows produced 42.4% and 35.3% more milk (10.89 vs. 7.65, kg/d) and fat-corrected milk (10.35 vs. 7.54, kg/d) than Bangladeshi local cattle. However, milk from crossbred cows displayed lower fat and protein content, although their somatic cell score (SCS) and energy-corrected milk remained similar. Additionally, milk from crossbred cows exhibited a longer coagulation time when compared to that of Bangladeshi local cattle. In conclusion, crossbred cows (Holstein × Local cattle) had improved body characteristics with greater milk yield than Bangladeshi local cattle; however, lower fat and protein contents in milk with longer coagulation time were noted. Full article

The aim of this work was develop a technological process for the manufacturing of an ice cream from sheep milk, enriched with both functional ingredients and probiotic bacteria. The studied process involved the use of an enriched milk (EM) obtained by mixing predetermined amounts of sheep skimmed milk concentrated by ultrafiltration (retentate), cream from sheep’s milk and whey, microparticulated whey proteins (MWP), obtained by ultrafiltration of sweet sheep whey as a source of whey proteins, marine algal oil from Schizochytrium spp. as a source of the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), inulin as a prebiotic fiber, and locust bean gum as a stabilizer. The resulting EM was inoculated with starter and aroma cultures together with the probiotic culture of Bifidobacterium animalis subsp. lactis (BB-12^®) in order to obtain a fermented functional product (FFP) with a physico-chemical composition similar to that of EM. FFP was the main ingredient (~80%, w/w) in the ice cream mixture. Two sucrose-alternative sweeteners (trehalose and erythritol), together with dextrose, were subsequently added to obtain the final ice cream formulation. The resulting ice cream met three nutritional claims: “Source of protein”, “Source of fiber” and “High in omega-3 fatty acids” listed in Regulations (EC) No 1924/2006 and (EU) No 116/2010. Furthermore, the ice cream satisfied the requirement of “probiotic food” according to the Italian Ministry of Health’s guidelines for probiotics. The nutritional characteristics of the ice cream, including the concentration of the probiotic culture, remained stable up to 120 days of storage at −20 ± 2 °C. Full article

Egyptian Jallab (EJ) is a conical candy (light to dark brown), manufactured from a part of sugar cane juice, that is used in the black honey industry. EJ is considered an unrefined sugar or a non-centrifugal form of sugar. The traditional use of Jallab is as candy, but it can also be used for making ice cream, cupcakes, biscuits, and toffee, as well as being used in other food applications. In this study, EJ was used as a sugar substitute in ice cream at 0, 25, 50, 75, and 100%. Total solids, titratable acidity, pH, protein, ash, fat, specific gravity, weight per gallon, viscosity, color attributes, total antioxidant activity, total phenolic content, and total flavonoid contents, as well as microbiological analyses, were tested. The total solids, protein, and ash in the Egyptian Jallab ice cream (EJIC) increased from 39.30, 4.85, and 0.87 to 41.19, 6.36, and 1.42, respectively. The gradual sugar substitution led to a significant increase in specific gravity and weight per gallon in pounds. The lightness (L*) of the ice cream decreased significantly due to the substitution of EJ for sugar. Moreover, there was a significant increase in a* (from 0.147 in control samples to 5.52 in treatment 4, which had 100% EJ). The changes in the b* values of Jallab ice cream samples were significantly increased due to the substitution of EJ for sugar. The control samples had a low value of antioxidant activity (21.53%) when compared with the treatment, which has EJ (88.82, 89.96, 91.98, and 92.14%) for EJIC1, EJIC2, EJIC3, and EJIC4, respectively. The total phenolic contents are 2.07, 3.03, 4.14, and 4.68 fold higher in the treatments with EJ substituted for sugar than in the control samples. Total flavonoid contents increased from 5.73 mg QE g⁻¹ in control samples (TC) to 14.68, 21.54, 30.48, and 34.15 mg QE g⁻¹ in EJIC1, EJIC2, EJIC3, and EJIC4 mg QE g⁻¹ in ice cream samples, respectively. Full article

Dietary particle size is one of the most relevant factors influencing rumen function and the selection of the most palatable components of the total mixed ration (TMR) by cows. The aim of this study was to evaluate the particle size distribution (PSD), homogeneity, sorting level, physically effective NDF (peNDF) content of TMRs, and production performances in Calabrian commercial dairy herds in southern Italy. The research was conducted in 13 farms, including 8 with hay-based TMR and 5 with silage-based TMR. All herds delivered fresh feed once a day. At each farm, the TMRs were examined with the Penn State Particle Separator (PSPS) to determine PSD, homogeneity, and feed sorting at two time points (i.e., at fresh feed delivery = T0 and 24 h after feed delivery = Tf). None of the diets that were evaluated met the recommended PSD, showing an excess of long fraction, very short fraction, or both. The homogeneity was good except for three diets, but particle selection raised some concerns in 85% of the farms due to the preferential consumption of the very short fraction by the cows, with rejection of the long fractions. All the diets analyzed met the Penn State University recommended neutral detergent fiber (NDF) values (>28%) except for one farm’s diet. In three of the TMRs observed, however, the content of peNDF > 8 mm was less than 15%. NDF and peNDF > 8 mm values of TMRs showed statistically significant correlations with milk fat content. Therefore, it is important to evaluate the chemical and physical properties of TMR to provide a consistent diet and prevent feed sorting. Full article

Salting influences microbial growth, enzymatic activity, and biochemical reactions during ripening, thus contributing to the final quality of cheese. The aim of this study was to evaluate the influence of different salting methods (dry salting at 12, 24, and 48 h; salting in brine; and salting of partially drained curd, before moulding) on the chemical (moisture and salt content), physicochemical (pH, titratable acidity, and water activity), and sensory characteristics (texture profile analysis, colour, and sensory attributes) of industrial blue-veined cheese. Dry-salted cheeses had lower moisture content and water activity, and higher salt/moisture content and acidity than those salted in brine and in the partially drained curd. Dry-salted cheeses were also characterised by higher values for hardness, fracturability, and instrumental gumminess. Dry-salted cheeses showed differences only in the red/green colour component (a*), with the cheeses salted in the partially drained curd being less greenish. All cheeses scored high (around 7) in the tasters’ overall impression, with the dry-salted cheeses at 12 and 24 h showing optimal growth and distribution of mould, as well as better flavour and texture. Full article

The growing global market of dairy products has led to the need for alternative approaches regarding whey valorization, which is the primary by-product of cheese and strained yogurt production. In this context, prebiotic galactooligosaccharides can be produced enzymatically from whey using commercially available β-galactosidases. A comparative study was conducted to assess the production of galactooligosaccharides from sweet and acid whey, thereby employing two commercial β-galactosidases from Aspergillus oryzae and Kluyveromyces lactis. The study considered the initial lactose content and enzyme load as variables. The maximum yields of galactooligosaccharides in concentrated sweet whey (15% w/v initial lactose) and raw acid whey (3.1% w/v initial lactose) reached 34.4 and 14.7% with lactase from Kluyveromyces lactis (0.13 U/mL), respectively. The corresponding galactooligosaccharide yields for lactase from Aspergillus oryzae were equal to 27.4 and 24.8% in the most concentrated sweet and acid whey, respectively, using enzyme loads of 2 U/mL in sweet whey and 1 U/mL in acid whey. Concerning the profile of the produced galactooligosaccharides, the Kluyveromyces lactis lactase hydrolyzed lactose more rapidly and resulted in higher levels of allolactose and lower levels of 6-galactosyl-lactose, compared to the lactase from Aspergillus oryzae, and achieved in both cases a polymerization degree of up to six. Full article

The objectives of this study were to evaluate the effects of supplementing the diet of high-producing Holstein cows with 2-hydroxy-4-(methylthio)-butanoate (HMTBa) on their milk production and composition, milk fatty acid profile, blood metabolites, and body parameters. The study was conducted in a commercial dairy herd in Paraná State, Southern Brazil. One hundred and fifty-eight multiparous cows were used in a randomized block design during 42 experimental days. Cows were distributed into two treatments: the control treatment cows received 100 g/cow/day of corn meal, while the HMTBa-supplemented cows received 35 g of HMTBa + 65 g/cow/day of corn meal. HMTBa supplementation did not alter milk production but improved milk fat content. Cows receiving HMTBa supplementation showed an increase in the concentration of milk medium-chain fatty acids. Serum levels of blood urea and aspartate aminotransferase were lower in HMTBa-supplemented cows. Cows supplemented with HMTBa increased their body condition score. In summary, HMTB supplementation in high-producing Holstein cows improved productive performance, particularly increased milk fat content, altered milk fatty acid profile, and changed some blood metabolites. Our findings contribute to our understanding of using a methionine analogue as a dietary strategy for optimizing milk quality in high-producing Holstein cows. Full article

Staphylococcus aureus is a major cause of subclinical mastitis in dairy cows, and its development of antibiotic resistance has limited treatment efficacy. Essential oils (EOs) are natural products with a wide range of antimicrobial properties that could be used to treat bovine mastitis. This study aims to investigate the antimicrobial activity of EOs against S. aureus isolated from subclinical bovine mastitis cases in the State of São Paulo—Brazil. A total of 14 S. aureus isolates were selected, based on the presence of biofilm-forming genes (icaA, icaD, and bap), and were cultured to a final concentration of 10³ CFU.mL⁻¹ for the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) analysis of five EOs (Citrus aurantium bergamia—bergamot, Copaifera reticulata—copaiba, Foeniculum vulgare—fennel, Zingiber officinale—ginger, and Ocimum basilicum—basil). The chemical compositions of the EOs were characterized using gas chromatography coupled with a mass-selective detector (GC/MSD). Basil and bergamot EOs exhibited the highest antimicrobial activity against S. aureus strains, with mean MIC/MBC values of 1.561 ± 0.223/2.806 ± 0.255 mg.mL⁻¹ and 2.782 ± 0.228/4.396 ± 0.198 mg.mL⁻¹, respectively. The primary compounds in basil EO were methyl-chavicol, linalool, and α-humulene, while bergamot EO predominantly contained linalyl acetate, limonene, and linalool. This research highlights the potential of basil and bergamot EOs as natural antimicrobial agents for treating bovine mastitis caused by S. aureus, offering a potential alternative to traditional antibiotics and contributing to animal welfare and public health. In addition, it emphasizes the need for further studies to validate the long-term effects, optimal dosages, and application methods. Full article

The aim of this study was to compare the physical, chemical, and microbiological features of bio-yoghurt that had been air-oven-dried at three temperatures (40, 50, and 60 °C) to those of fresh bio-yoghurt. The results showed that drying bio-yoghurt at 40–60 °C decreased the number of probiotic starter bacteria in dried yoghurt products compared to fresh bio-yoghurt. The dried yoghurt’s moisture, protein, fat, carbohydrate, and ash contents were 4.16–4.55%, 38.22–40.02%, 1.33–1.43%, 47.94–49.45%, and 6.37–6.55%, respectively. The pH and total acidity levels of dried yoghurt were within acceptable ranges at various temperatures and storage durations. At different temperatures, the viscosity values of the products decreased by 620–550 cp; however, the hygroscopicity values remained constant. During a 90-day storage period, the dried yoghurt product’s physical, chemical, and microbiological characteristics remained within acceptable levels. Using a drying temperature of 40–50 °C kept the number of live bacteria below acceptable ranges during storage periods. Lactobacillus acidophilus counts were 6.75 and 6.70 log CFU/g, respectively, whereas Bifidobacterium bifidum numbers were 6.66 and 6.08 log CFU/g, respectively. In conclusion, drying bio-yoghurt in an air oven at 40–50 °C provided a dried product with a high number of viable probiotic bacteria and satisfactory physicochemical characteristics after 3 months. Full article

This study aimed to evaluate the effects of replacing earless corn silage (ECS) with cactus cladodes (CC; Opuntia spp.) and sugarcane bagasse (SB) on nutrient intake, digestibility, feeding behavior, milk yield (MY), and composition of lactating dairy cows. Ten Holstein cows, weighing 571 ± 97.0 kg and producing 23.0 ± 4.4 kg of milk per day, were assigned to two contemporaneous 5 × 5 Latin squares. Treatments consisted of five levels of ECS replacement with CC plus SB (0, 25, 50, 75, and 100%). The results showed a linear increase in dry matter (DM) intake (p < 0.05) (15.98 and 18.73 kg/day) and a quadratic increase (p < 0.05) in crude protein and energy intake (2.97 kg/day and 27.52 Mcal/day at 95.4 and 88.6% substitution, respectively). Apparent DM digestibility increased (p < 0.05), but fiber digestibility decreased linearly (p < 0.05). Treatments had a quadratic effect (p < 0.05) on MY and fat-corrected MY (24.17 kg/day and 21.9 kg/day at 63.9% and 38.6% CC plus SB, respectively). Milk fat (3.26 and 2.35%) and total solids content decreased linearly (p < 0.05), whereas the percentages of protein, lactose, and nonfat solids increased (p < 0.05). Additionally, the CC–SB diets linearly reduced the time spent on feeding and rumination and total chewing time. For Holstein cows fed common semiarid diets, milk production can be maximized by replacing 38.6% of ECS with CC plus SB. Full article

Stable flies, Stomoxys calcitrans (L.), are important biting pests of dairy cattle and other livestock. These flies develop in decaying organic matter, such as soiled animal bedding. As part of a larger study of management options in organic dairy production, leftover debris from two winter housing systems, outdoor straw packs and indoor sawdust compost barns, were analyzed for the numbers and size of stable flies produced the following summer. The study was conducted at the University of Minnesota’s West Central Research and Outreach Center in Morris. During winter, independently managed groups of 20 cows were housed from November to May in replicate housing systems. After the cows were moved to summer pasture, fly traps were assembled in the leftover piles (n = 4): emergence traps to quantify stable fly emergence and Olson traps to study ambient adults. The size of the emerged flies and 30 ambient adult females were measured. The sampled females were also dissected to determine the gonotrophic age. During peak emergence in both years, straw piles produced significantly more stable flies than compost bedding, but the adults were equal in size. The Olson traps showed adults were equally abundant at both sources. Over 60% of the females dissected were previtellogenic, indicating local emergence. Compost bedding is useful in managing stable fly numbers, while straw presents a serious stable fly production liability if not disposed of properly. Full article

The aim of this study was to estimate genetic parameters of somatic cell score (SCS) and fat plus protein yield (FPY) using repeatability (RM) and random regression (RRM) models in Florida goats. The data consisted of 340,654 test-day controls of the first three lactations, and the pedigree contained 36,144 animals. Covariance components were estimated with a bivariate RM and RRM using the REML approach. Both models included as fixed effects the combination of herd and control date, litter size, kidding number and lactation length, and as random effects, the additive genetic and permanent environmental effects. A variation in the shape of the genetic parameters along the lactation curve was observed for both traits, and h² oscillated between 0.272 and 0.279 for SCS and 0.099 and 0.138 for FPY. The genetic correlation between SCS and FPY was negative and medium (−0.304 to −0.477), indicating that a low-SCS EBV is associated with a genetic predisposition to high FPY production. Our results showed that given the magnitude of h² for SCS and its r_g with FPY, the SCS could be used as a selection criterion to increase resistance to mastitis, thus obtaining an improved dairy and cheese aptitude in this breed. Full article