The characteristic cooking-stretching process for pasta-filata cheese production applies shear forces accompanied by thermal treatment to form a fibrous cheese structure. This work aims to summarize the traditional and novel cooking-stretching equipment and related parameters, as well as shear-induced alterations in the micro-, meso-, and macro-behaviour of mozzarella cheese. Apparatus like cooker-stretchers, extruders, Thermomix, etc., have been summarized. Operating parameters, e.g., screw speed, were found less convenient to describe the process, in comparison with system variables like specific mechanical energy. These variations induce different cheese properties, including anisotropy, rheology, stretchability, and those related to fibre formation. Nowadays, researchers are devoted to 1) better qualifying and quantifying the system variables, and 2) developing online techniques to monitor the dynamic changes in components that occur during processing. This review provides an idea for researchers and manufacturers to study and produce customized pasta-filata cheese products, and facilitate improvements in controlling dairy processing and innovating processing approaches.
ABSTRACT: Unknown parent groups (UPG) model missing parentships according to breed, year, and pathway of selection. Genetic evaluations need a sensible definition of rules to form UPG to ensure their accurate estimation. With more complex evaluations, systematic rules are needed to form UPG. We propose several methods to ascertain informativity and join consecutive UPG within breed and pathway. First, a pseudocount of records based on descendants with record can be easily computed from a pedigree and a list of animals in records by propagating fractions of one from the flagged animals to ancestors through the pedigree, from youngest to oldest. Then, 2 rules are proposed: the first joins UPG forward in time until records appear, and the second joins consecutive UPG backward in time to achieve a minimum pseudocount. Finally, a simplified model estimates the precision of contrasts of UPG. Computations are feasible even for very large datasets. We illustrate with 2 examples from all-breed US traditional BLUP evaluation for yield and health traits. For yield traits, the number of pseudorecords is very high, and joining UPG occurs mainly in small breeds. Joining or not results in very similar estimated breeding values and genetic trends. For health traits, joining UPG occurs for all breeds, and more intensely for small breeds. Joining or not joining UPG resulted, for some trait-breed combinations, in quite different genetic trends and estimated breeding values. The approximated contrasts across all pairwise UPG show that the joining strategies achieve more precision, in the form of lower SE.
Olga Wellnitz, Benjamin Jenni, Natascha Stoffel
et al.
Oxytocin (OT), the peptide hormone whose release from the pituitary is essential to induce milk ejection, has been measured in blood plasma of dairy cows for decades. In the present study we tested the possible use of saliva instead of blood sampling to record OT release by using a commercially available ELISA for salivary OT measurement both in saliva and blood plasma. Measurements were performed to detect the expected OT increase in response to intravenous OT injections and during machine milking. Three dairy cows were injected with increasing dosages (0.5, 1, 5, and 10 IU i.v.) of OT, and blood and saliva samples were repeatedly taken during 1 h after injection. Furthermore, 5 cows were milked and blood and saliva samples were taken during and until 20 min after milking. To verify the expected release of OT during milking, we used our established RIA for measurements in plasma in parallel to ELISA measurements. Our results showed that the commercial ELISA kit used was able to detect the OT concentrations in both saliva and plasma. The massive increase of OT concentration after OT injection and during milking could be detected in plasma with both RIA and ELISA. However, we did not observe any change of salivary OT within the duration of the experiments. Our results showed that short-term increases in blood plasma OT, such as in response to OT injection or milking, were not reflected by increasing salivary OT concentrations.
Marcos Busanello, Maihury Corrêa Santo, Rodrigo de Almeida
The relationship between live BW (LBW) and mature BW (MBW) is critical for formulating optimal diets in dairy cattle, particularly regarding target BW (TBW) growth. Current nutritional guidelines suggest dairy cows reach MBW by the third calving (based on Holstein data), whereas beef cows reach it by the fourth calving. This study investigated LBW variations among different parities in Holstein and Jersey lactating cows, assessing the applicability of established proportion of MBW (%MBW) values across breeds. An observational study was conducted in dairy herds in Paraná State, Southern Brazil, comprising 19 Holstein and 9 Jersey herds, collecting LBW data at various growth stages. Nonlinear mixed models indicated MBW values of 705 kg for Holsteins and 460 kg for Jerseys, with Jersey cows showing faster maturation rate. Our findings revealed both breeds achieved recommended TBW verified by the %MBW at critical growth stages, but primiparous Jerseys exceeded the recommended values at first calving. Notably, while Holstein cows reach MBW by their third lactation, Jersey cows seem to achieve it by the fourth lactation, similar to beef cattle. This highlights the need for revised nutritional standards that better reflect the growth potential of different dairy breeds.
ABSTRACT: Genetic enhancement of feed efficiency can improve the economic sustainability and environmental responsibility of dairy farming. Although genetic selection holds promise for improving feed efficiency across the lifespan of dairy cows, comprehensive data spanning whole lactations or even a productive lifetime are currently limited. To address this, we used production data and data from a camera-based feed intake and BW recording system, along with records of production, feed intake, and weight on Holstein cows from a research herd. We aimed to estimate variance components for a multivariate, multiparity model of production, feed intake, and BW data to calculate genetic residual feed intake (gRFI) for each of the Nordic breeds (Holstein, Jersey, and Red Dairy Cattle). Our approach included investigating a new definition of energy balance (EBbody) calculated from changes in body reserves, serving as an energy sink in gRFI. The data in our analysis consisted of 4,751 Holstein cows (7,851 lactations), 2,068 Jersey cows (3,486 lactations), and 3,235 Red Dairy Cattle cows (5,419 lactations). We used Gibbs sampling to estimate posterior means and SD for all model parameters. Our findings revealed moderate lactation-wise heritability of gRFI (0.15–0.38) across all breeds and parities. Moreover, gRFI genetic correlations varied (−0.2 to 0.4) between early- and mid- to late-lactation stages across all breeds, and for lactation-wise gRFI, there were moderately high genetic correlations (0.39–0.59) between primi- and multiparous lactations across the 3 breeds. Those results suggest the importance of recording phenotypes in most time periods within and across lactations. Our analysis indicated that improving gRFI with one genetic SD unit corresponded to a 2% to 3% gain in net return profit per cow-year, with no or minimal impact on production and body reserve management. We demonstrated the feasibility of incorporating EBbody into gRFI. Comparing gRFI calculated with EBbody or changes in BW as an energy sink trait for body reserve management were highly genetically correlated (>0.95). This result shows that the choice of the energy sink trait for body reserve management in gRFI will yield limited reranking among cows and sires when based on BW records only. However, EBbody offers an opportunity to incorporate BCS information without increasing the number of genetic parameters to be estimated, but it relies on parameters estimated in experimental settings. In conclusion, our study demonstrates the feasibility of developing a model for gRFI over most of the productive lifetime of dairy cattle, offering significant economic benefits without compromising productivity or body reserve management. Moving forward, comprehensive recording schemes covering whole lactations and productive lifetimes are advantageous for accurate selection indices of gRFI.
Mary Beth de Ondarza, Vinícius Carneiro de Souza, Ermias Kebreab
et al.
ABSTRACT: Supplemental dietary rumen available fats show promise as enteric methane (eCH4) mitigators for lactating dairy cows. However, concerns include variability in eCH4 response and possible negative effects on dairy cow performance. Successful implementation of this mitigation option requires better prediction of responses specifically to rumen available fatty acids (FA) as well as understanding the modulating effects of other dietary and animal characteristics. Using meta-analytic and meta-regression techniques, 35 published studies with diet definition were used to assess changes in eCH4 emissions and lactation performance associated with supplemental fat, specific supplemental rumen available FA types, and other dietary characteristics. Enteric CH4 (g/d) was reduced by 3.77% per percentage unit of supplemental rumen available ether extract (EE). Supplemental rumen available PUFA (C18:2 and C18:3) and UFA (C18:1, C18:2, C18:3) mitigated eCH4 (g/d) emissions in dairy cows by 6.88 and 4.65% per percentage unit increase, respectively. The anti-methanogenic effects of PUFA, MUFA and MCFA increased with correspondingly greater basal dietary levels of each FA type. Higher rumen-degradable starch (RDS; >18% DM) in the basal diet promoted greater reductions in eCH4 yield (eCH4/DMI, g/kg) with supplemental rumen available PUFA and UFA. Both milk fat percentage and yield (kg/d) were reduced with rumen available fat supplementation with a reduction of 7.8% and 6.0%, respectively, relative to control diets. Our results highlight the importance of determining basal levels of the rumen available FA before providing supplemental rumen available FA as an option for enteric eCH4 mitigation. Dairy nutritionists can use estimates generated from this analysis to predict changes in eCH4 emissions and dairy cow performance associated with dietary supplementation of rumen available EE and specific rumen available FA types for the purpose of eCH4 mitigation.
ABSTRACT: As the call for an international standard for milk from grassland-based production systems continues to grow, so too do the monitoring and evaluation policies surrounding this topic. Individual stipulations by countries and milk producers to market their milk under their own grass-fed labels include a compulsory number of grazing days per year (ranging from 120 d for certain labels to 180 d for others), a specified amount of herbage in the diet, or a prescribed dietary proportion of grassland-based forages (GBF) fed and produced on-farm. As these multifarious policy and label requirements are laborious and costly to monitor on-farm, fast economical proxies would be advantageous to verify the proportion of GBF consumed by the cows in the final product. With this in mind, we employed readily available mid-infrared spectral data (n = 1,132 spectra) from routine milk controls to develop binary classification models for 4 main feed groups from a primarily forage-based diet: total GBF (≥50% [n = 955], ≥75% [n = 599], ≥85% [n = 356]), pasture (≥20% [n = 451], ≥50% [n = 284], ≥70% [n = 152]), fresh herbage (pasture + fresh herbage indoor feeding; ≥20% [n = 517], ≥50% [n = 325], ≥70% [n = 182]), and whole plant corn (fresh + conserved; ≥10% [n = 646], ≥30% [n = 187]), with the latter as a negative control. We compared 4 machine learning methods to assess which statistical model performs best at discriminating these classes. Three of these models have not yet been tested for herd-level dietary proportion classification, and all 4 follow completely different approaches: least absolute shrinkage and selection operator (LASSO), partial least squares discriminant analysis (PLS-DA), random forest (RF), and support vector machines (SVM). Seasonality has been a missing element from previous dietary herbage proportion classification models. As grazing and fresh herbage indoor feeding are highly dependent on the season, we developed an indicator to incorporate seasonality in a consistent, unbiased manner into our models. We also tested 3 sets of covariates. The first set included only mid-infrared spectra derived data, the second included mid-infrared spectra derived data plus seasonality indices and the third included mid-infrared spectra derived data, seasonality indices and additional herd specific information (DIM, breed, and parity). Of the 4 machine learning algorithms tested for the binary classification of GBF proportion at herd level, LASSO and PLS-DA performed best according to evaluation metrics; however, the RF and SVM models were not far behind the best performing model evaluation metrics in each feed category. Our best performing model, the LASSO model containing seasonality indices and herd specific information, classified total GBF ≥50% with an accuracy of 78.6%, precision of 85.1%, sensitivity of 90.6%, specificity of 14.1%, and F1 score (harmonic mean of precision and sensitivity) of 87.7%; this was very similar to the PLS-DA model. Our results suggest that in general, LASSO and PLS-DA machine learning algorithms perform better for dietary GBF classification than RF or SVM algorithms.
Minas Frescal cheese is a relevant nutritional source in the diet, and its consumption is expressive and growing. However, the unsaturated fatty acids and cholesterol present in its lipid fraction are susceptible to oxidation, with implications for health issues, due to quality losses and the formation of harmful compounds for consumers. Due to the importance of dairy products associated with the enhancement of food quality and clean production practices, it is important to the lipid fraction, identifying the composition of fatty acids and cholesterol content. The food industry uses different strategies for the use of antioxidants to reduce lipid oxidation and increase shelf life. Herbs and spices are natural ingredients widely used not only as a food flavoring but also for their health attributes. The present study is a literature review on the lipid composition of Minas Frescal cheese and the use of natural additives to protect against lipid oxidation. Thus, the use of vegetable sources in Minas Frescal cheese, in addition to providing flavor, aroma, and color, is an option for natural preservatives to replace synthetic additives, and presents antioxidant, antimicrobial, and anticancer compounds, with protective potential against undesirable reactions, corroborating to consumer demand for healthy food.
J. Denis-Robichaud, N. Barbeau-Grégoire, M.-L. Gauthier
et al.
ABSTRACT: The objective of this cross-sectional study was to estimate the validity of laboratory culture, Petrifilm and Tri-Plate on-farm culture systems, as well as luminometry to correctly identify IMI at dry-off in dairy cows, considering all tests to be imperfect. From September 2020 until December 2021, we collected composite milk samples from cows before dry-off and divided them into 4 aliquots for luminometry, Petrifilm (aerobic count), Tri-Plate, and laboratory culture tests. We assessed multiple thresholds of relative light units (RLU) for luminometry, and we used thresholds of ≥100 cfu/mL for the laboratory culture, ≥50 cfu/mL for Petrifilm, and ≥1 cfu for Tri-Plate tests. We fitted Bayesian latent class analysis models to estimate the sensitivity (Se) and specificity (Sp) for each test to identify IMI, with 95% credibility interval (BCI). Using different prevalence measures (0.30, 0.50, and 0.70), we calculated the predictive values (PV) and misclassification cost terms (MCT) at different false negative-to-false-positive ratios (FN:FP). A total of 333 cows were enrolled in the study from one commercial Holstein herd. The validity of the luminometry was poor for all thresholds, with an Se of 0.51 (95% BCI = 0.43–0.59) and Sp of 0.38 (95% BCI = 0.26–0.50) when using a threshold of ≥150 RLU. The laboratory culture had an Se of 0.93 (95% BCI = 0.85–0.98) and Sp of 0.69 (95% BCI = 0.49–0.89); the Petrifilm had an Se of 0.91 (95% BCI = 0.80–0.98) and Sp of 0.71 (95% BCI = 0.51–0.90); and the Tri-Plate had an Se of 0.65 (95% BCI = 0.53–0.82) and Sp of 0.85 (95% BCI = 0.66–0.97). Bacteriological tests had good PV, with comparable positive PV for all 3 tests, but lower negative PV for the Tri-Plate compared with the laboratory culture and the Petrifilm. For a prevalence of IMI of 0.30, all 3 tests had similar MCT, but for prevalence of 0.50 and 0.70, the Tri-Plate had higher MCT in scenarios where leaving a cow with IMI untreated is considered to have greater detrimental effects than treating a healthy cow (i.e., FN:FP of 3:1). Our results showed that the bacteriological tests have adequate validity to diagnose IMI at dry-off, but luminometry does not. We concluded that although luminometry is not useful to identify IMI at dry-off, the Petrifilm and Tri-Plate tests performed similarly to laboratory culture, depending on the prevalence and importance of the FP and FN results.
Waste is an inherent and unavoidable part of any process which can be attributed to various factors such as process inefficiencies, usability of resources and discarding of not so useful parts of the feedstock. Dairy is a burgeoning industry following the global population growth, resulting in generation of waste such as wastewater (from cleaning, processing, and maintenance), whey, and sludge. These components are rich in nutrients, organic and inorganic materials. Additionally, the presence of alkaline and acidic detergents along with sterilizing agents in dairy waste makes it an environmental hazard. Thus, sustainable valorization of dairy waste requires utilization of biological methods such as microbial treatment. This review brings forward the current developments in utilization and valorization of dairy waste through microbes. Aerobic and anaerobic treatment of dairy waste using microbes can be a sustainable and green method to generate biofertilizers, biofuels, power, and other biobased products.
Listeria monocytogenes is one of the most important foodborne pathogens. This microorganism is a serious concern in the ready-to-eat (RTE) meat and dairy-ripened products industries. The use of lactic acid bacteria (LAB)-producing anti-L. monocytogenes peptides (bacteriocins) and/or lactic acid and/or other antimicrobial system could be a promising tool to control this pathogen in RTE meat and dairy products. This review provides an up to date about the strategies of use of LAB and their metabolites in RTE meat products and dairy foods by selecting the most appropriate strains, by analysing the mechanism by which they inhibit L. monocytogenes and methods of effective application of LAB, and their metabolites in these kinds of products to control this pathogen throughout the processing and storage. The selection of LAB with anti-L. monocytogenes activity allows to dispose of effective strains in meat and dairy-ripened products, achieving reductions form 2–5 logarithmic cycles of this pathogen throughout the ripening process. The combination of selected LAB strains with antimicrobial compounds, such as acid/sodium lactate and other strategies, as the active packaging could be the next future innovation for eliminating risk of L. monocytogenes in meat and dairy-ripened products.
ABSTRACT: Growing interest in the manufacture of extended shelf-life (ESL) milk, which is typically achieved by a high-temperature treatment called ultra-pasteurization (UP), is driven by distribution challenges, efforts to reduce food waste, and more. Even though high-temperature, short-time (HTST) pasteurized milk has a substantially shorter shelf life than UP milk, HTST milk is preferred in the United States because consumers tend to perceive UP milk as less desirable due to the “cooked” flavor associated with high-temperature processing. While ESL beyond 21 d may be possible for HTST, the survival and outgrowth of psychrotolerant aerobic spore-forming bacteria can still be a limitation to extending shelf life of HTST milk. Microfiltration (MF) is effective for reducing vegetative microorganisms and spores in raw milk, but it is unclear what the effects of membrane pore size, storage temperature, and milk type (i.e., skim vs. whole) are on the microbial shelf life of milk processed by both MF and HTST pasteurization. To investigate these factors, raw skim milk was MF using different pore sizes (0.8 or 1.2 μm), and then MF skim milk and standardized whole milk (MF skim with heat-treated [85°C for 20 s] cream) were HTST pasteurized at 75°C for 20 s. Subsequently, milk was stored at 3°C, 6.5°C, or 10°C and total bacteria counts were measured for up to 63 d. An ANOVA indicated that mean bacterial concentrations between storage temperatures were significantly different from each other, with mean maximum observed concentrations of 3.67, 5.33, and 8.08 log10 cfu/mL for storage temperatures 3°C, 6.5°C, and 10°C, respectively. Additionally, a smaller difference in mean maximum bacterial concentrations throughout shelf life was identified between pore sizes (<1 log cfu/mL), but no significant difference was attributed to milk type. An unexpected outcome of this study was the identification of Microbacterium as a major contributor to the bacterial population in MF ESL milk. Microbacterium is a psychrotolerant, thermoduric gram-positive, non-spore-forming rod with a small cell size (∼0.9 μm length and ∼0.3 μm width), which our data suggest was able to permeate the membranes used in this study, survive HTST pasteurization, and then grow at refrigeration temperatures. While spores continue to be a key concern for the manufacture of MF, ESL milk, our study demonstrates the importance of other psychrotolerant, thermoduric bacteria such as Microbacterium to these products.
ABSTRACT: Yak milk is rich in essential milk proteins of nutritional and therapeutic value. In this study, whey proteins of milk from 3 yak breeds (Gannan, GN; Huanhu, HH; Maiwa, MW) in China were comprehensively identified and compared using a data-independent acquisition quantitative proteomics approach. A total of 632 proteins were identified in yak milk whey samples, in which immune-related proteins were abundant. Compared with other milks, more proteins were involved in oxidation-reduction process and with ATP binding. In addition, we identified 96, 155, and 164 differentially expressed proteins (DEP) for GN versus HH, GN versus MW, and HH versus MW, respectively. “Phagosome” and “complement and coagulation cascades” were the most significant pathways for DEP of GN versus HH and GN or HH versus MW yak milk based on the Kyoto Encyclopedia of Genes and Genomes pathway analysis. Protein-protein interaction network analysis showed that DEP for the 3 comparisons had significant biological interactions but were associated with different functions. The results provide useful information on yak milk from different breeds in China, and elucidate the biological functions of yak milk proteins.
ABSTRACT: The objective of this study was to identify metabolites associated with metritis and use them for identification of cellular mechanisms affected during transition into lactation. Holstein cows (n = 104) had blood collected in the prepartum period (d −14 ± 6 relative to calving), at calving (d 0), and at the day of metritis diagnosis (d 7 ± 2 after calving). Cows with reddish or brownish, watery, and fetid discharge were diagnosed with metritis (n = 52). Cows with metritis were paired with herdmates without metritis (n = 52) based on days in milk. The metabolome of plasma samples was evaluated using untargeted gas chromatography time-of-flight mass spectrometry. Univariate analyses included t-tests and fold change analyses. Metabolites with false discovery rate adjusted P ≤ 0.10 on t-tests were used for partial least squares discriminant analysis coupled with permutational analysis using 2,000 permutations. Metabolites with false discovery rate adjusted P ≤ 0.10 on t-tests were also used for enriched pathway analyses and identification of cellular processes. Cows that developed metritis had affected cellular processes associated with lower amino acid metabolism in the prepartum period, greater lipolysis, cell death, and oxidative stress at calving and at metritis diagnosis, and greater leukocyte activation at calving, but lower immune cell activation at metritis diagnosis. In summary, cows that developed metritis had plasma metabolomic changes associated with greater lipolysis, oxidative stress, and a dysregulated immune response which may predispose cows to metritis development.
S. G. Machado, F. Baglinière, Sophie Marchand
et al.
Raw bovine milk is highly nutritious as well as pH-neutral, providing the ideal conditions for microbial growth. The microbiota of raw milk is diverse and originates from several sources of contamination including the external udder surface, milking equipment, air, water, feed, grass, feces, and soil. Many bacterial and fungal species can be found in raw milk. The autochthonous microbiota of raw milk immediately after milking generally comprises lactic acid bacteria such as Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc species, which are technologically important for the dairy industry, although they do occasionally cause spoilage of dairy products. Differences in milking practices and storage conditions on each continent, country and region result in variable microbial population structures in raw milk. Raw milk is usually stored at cold temperatures, e.g., about 4°C before processing to reduce the growth of most bacteria. However, psychrotrophic bacteria can proliferate and contribute to spoilage of ultra-high temperature (UHT) treated and sterilized milk and other dairy products with a long shelf life due to their ability to produce extracellular heat resistant enzymes such as peptidases and lipases. Worldwide, species of Pseudomonas, with the ability to produce these spoilage enzymes, are the most common contaminants isolated from cold raw milk although other genera such as Serratia are also reported as important milk spoilers, while for others more research is needed on the heat resistance of the spoilage enzymes produced. The residual activity of extracellular enzymes after high heat treatment may lead to technological problems (off flavors, physico-chemical instability) during the shelf life of milk and dairy products. This review covers the contamination patterns of cold raw milk in several parts of the world, the growth potential of psychrotrophic bacteria, their ability to produce extracellular heat-resistant enzymes and the consequences for dairy products with a long shelf life. This problem is of increasing importance because of the large worldwide trade in fluid milk and milk powder.
In the present study, 124 samples of milk and milk products were analyzed for the presence of aflatoxin M<sub>1</sub> (AFM<sub>1</sub>), which were purchased from the central cities of Punjab, Pakistan. The analysis was carried out using reverse-phase liquid chromatography, which was equipped with a fluorescence detector. The results showed that 66 samples (53.8%) of raw milk and milk products were found to be contaminated with detectable levels of AFM<sub>1</sub> above ≤50 ng/L, and 24.2% of the samples had levels of AFM<sub>1</sub> higher than the permissible limit of the European Union (EU; 50 ng/kg). In total, 53.6% of the raw milk, 57.8% of the UHT (ultra-heat-temperature) milk, 45% of the powdered milk, 57.1% of the yogurt, 55.5% of the cheese, and 50% of the buttermilk samples had levels higher than the LOD, i.e., 4 ng/L. The highest mean of 82.4 ± 7.8 ng/kg of AFM<sub>1</sub> was present in the positive samples of raw milk. The highest dietary intake of AFM<sub>1</sub> was found in infants’ milk (5.35 ng/kg/day), UHT milk (1.80 ng/kg/day), powdered milk (5.25 ng/kg/day), and yogurt (1.11 ng/kg/day). However, no dietary intake was detected in the cheese and butter milk samples used for infants. The results from the undertaken work are beneficial for establishing rigorous limits for AFB<sub>1</sub> in animal feed, especially considering the high prevalence rate of hepatitis cases in the central cities of Punjab, Pakistan.
Muhammad Anees Ur Rehman, Khurram Ashfaq, Faiza Iqbal
et al.
Popular dairy product yoghurt is fermented with the potential of health-promoting characteristics. It is considered a nutrient-dense foodstuff enriched with calcium, providing bioavailable form. The essential amino acids required for optimal health are present in Yoghurt. It may also be a probiotic carrier that may transfer large probiotic bacteria into the body, providing unique health benefits. Milk proteins in yoghurt are of higher biological value. Yoghurt is also said to help with lactose tolerance, immunological boosting, and the prevention of gastrointestinal problems. Consumer demand for Yoghurt and its products has surged due to these well-known health benefits, and it has become the fastest-growing dairy industry. Yoghurts are available in various styles, differing in fat content, flavor profile, and texture, making them suited for multiple meal settings. The current review covers yoghurt history, varieties, processing technology, and the nutritional profile of Yoghurt.
ABSTRACT: Dairy cows are motivated to access dry lying surfaces and will seek protection from wind and rain, but winter conditions may limit these opportunities when cows are managed outdoors. The primary aim of this observational study was to determine the effects of weather and paddock soil conditions on lying behavior of dairy cows managed outdoors during winter and fed crop in situ, a practice occurring in New Zealand with year-round grazing of dairy cows. A secondary aim was to characterize eating and ruminating behaviors during winter weather and paddock soil conditions. Four groups (99 nonlactating, pregnant cows each) were managed on 4 outdoor paddock areas on the same farm; the groups were fed pasture silage and grazed either kale (2 groups) or fodder beet (2 groups). Behaviors were recorded using validated leg-based (lying behavior) and ear-based (eating and ruminating time) accelerometers on 30 focal cows in each group over 32 d. Soil depth and wetness were scored daily at 25 points along 4 transects within each paddock area using recognized technical measures (penetrometer, soil volumetric water content), which were compared with practical tools for farmer use (ruler, moisture meter, percentage of sites in paddock scored as dry, wet, sodden, or with surface water pooling). Rainfall occurred most days during the study (mean 1.6 mm/d; maximum 12.2 mm/d), resulting in wet and muddy paddocks (mud depth with ruler: mean 6 cm, maximum 18 cm; paddock sites scored as wet or sodden: mean 34%, maximum 100%; paddock sites with surface water pooling: mean 27%, maximum 100%). Group lying time was 9.6 ± 2.3 h/d (mean ± standard deviation); however, 21% of cows consistently lay less than 8 h/d (to a minimum of 4.9 h/d). A mixed regression model tested the effects of daily weather and paddock soil conditions on daily lying time, with group as the observational unit, day as repeated measure, crop type as a fixed effect, crop type interactions with explanatory variables, and random intercepts of group and paddock within group. Lying time was less on the day of and day after rainfall (24 and 29 min/d less for 1 mm increase in rainfall, respectively). Two days after rainfall, lying time rebounded to about 1 h longer than before the rainfall. On the day after the heaviest rainfall event, group average lying time was only 2.5 ± 1.9 h/d (mean ± standard deviation); in 2 groups, 30% and 38% of cows, respectively, did not lie down at all for 24 h. Lying time decreased with deteriorating paddock soil conditions, especially with increasing surface water pooling, suggesting that this may be a useful measure to estimate the quality of the lying surface. Descriptively, ruminating time appeared to decrease with increased surface water pooling, possibly due to decreased lying time. Our results demonstrated that dairy cows could experience periods of short or no lying time during inclement weather and muddy paddock soil conditions. Prior rainfall and surface water pooling may be useful measures to determine if lying time, and thus animal welfare, are compromised.