Dairy, Volume 2, Issue 1 (March 2021) – 14 articles

Enzymatic cross-linking by microbial transglutaminase is a prominent approach to modify the structure and techno-functional properties of food proteins such as casein. However, some of the factors that influence structure-function-interrelations are still unknown. In this study, the size of cross-linked sodium caseinate nanoparticles was modulated by varying the ionic milieu during incubation with the enzyme. As was revealed by size exclusion chromatography, cross-linking at higher ionic strength resulted in larger casein particles. These formed acid-induced gels with higher stiffness and lower susceptibility to forced syneresis compared to those where the same number of ions was added after the cross-linking process. The results show that variations of the ionic milieu during enzymatic cross-linking of casein can be helpful to obtain specific modifications of its molecular structure and certain techno-functional properties. Such knowledge is crucial for the design of protein ingredients with targeted structure and techno-functionality. Full article

Glycation between proteins and sugars via the Maillard reaction has been shown to improve the heat stability of proteins. In this study, inulin, a healthy dietary fiber, was glycated with whey protein isolate (WPI), and the effects of reaction conditions were investigated. Conjugates were prepared by freeze-drying mixed WPI and inulin solutions at 1:1 to 6:1 WPI-to-inulin weight ratios followed by dry heating at 70, 75, or 80 °C for 12 to 72 h under uncontrolled, 44%, or 80% relative humidity. Heat stability was evaluated by turbidity, particle size, and rheological measurements. Degree of glycation was assessed by quantifying the loss of amino groups and the formation of the Amadori compounds. Results showed that conjugation led to improved heat stability, as shown by decreased turbidity and particle size as well as the ability to maintain the viscosity compared to control samples. Based on the loss of amino groups, the optimum glycation conditions were achieved with WPI–inulin mixtures at 2:1, 4:1, and 6:1 weight ratios and 80 °C temperature for 12 to 72 h without controlling the relative humidity. The improved heat stability could be due to an increase in negative charge as well as increased structural stabilization of the proteins. Under a limited degree of glycation, glycated WPI–inulin conjugates have great potential to be utilized as food ingredients, especially in the beverage industry. Full article

In dairy farms, the feeding cost, which includes the expenses for purchased feed but also the expenses for feed production, constitutes a very large part of production cost (more than 60%), which indicates the economic importance of the feeding strategy. This study discerns three different feeding strategies: landless farms only purchasing feed from markets (“Purchasing”), farms for which home-grown feeds stand for more than 10% of feeding costs (“Producing”) and farms with less than 10% home-grown feeds (“Multi-purpose”). Based on technical and economic data from 47 dairy cow farms in Greece, alternative scenarios of development of the dairy sector are determined taking into account the dependence on on-farm feed production. Through a parametric programming model, the study provides insights regarding the optimal structure of the system under different scenarios (changing availability of variable capital, changes in milk prices). The results indicate that “Purchasing” farms are the preferred option when variable capital is abundant and milk prices are satisfactory, while “Producing” are the ones surviving with milk prices significantly lower than the actual ones in Greece and European Union. “Multi-purpose” farms perform worse than the other two and are sidelined in both scenarios, as they do not seem to be able to specialize in the dairy enterprise or in crop production and thus to minimize costs. Full article

The aim of this work was to evaluate, by an untargeted metabolomics approach, changes of milk metabolites induced by the replacement of soybean hulls with cocoa husks in the ewes’ diet. Animals were fed with a soybean diet integrated with 50 or 100 g/d of cacao husks. Milk samples were analyzed by an ultra high performance liquid chromatograph coupled to a time of flight mass spectrometer (UHPLC-QTOF-MS) platform. Multivariate statistical analysis showed that the time of sampling profoundly affected metabolite levels, while differences between treatments were evident at the fourth week of sampling. Cocoa husks seem to induce level changes of milk metabolites implicated in the thyroid hormone metabolism and ubiquinol-10 biosynthesis. Full article

Precision livestock farming (PLF) supports the development of sustainable dairy production. The sensors used in PLF provide valuable information for farm management, but they must be validated to ensure the accuracy. The goal of this study was to validate and use the RumiWatch sensor (RWS; Itin+Hoch GmbH, Liestal, Switzerland) to differentiate prehension bites, eating chews, mastication chews and rumination chews in pressure-based system. Twenty cows were used for 14 days to provide a validation dataset. The concordance correlation coefficient (CCC) was adopted to test the concordance between the RumiWatch sensor and video observation. The RumiWatch sensor performed well in counting prehension bites (CCC = 0.98), eating chews (CCC = 0.95) and rumination chews (CCC = 0.96), while it showed an acceptable concordance in counting mastication chews with video observation (CCC = 0.77). Moderate correlations were found between eating chews and daily milk production: daily milk production (kg/day) = 0.001151 × eating chews (chews/day) − 11.73 (R² = 0.31; standard error (SE) = 8.88; p = 0.011), and between mastication chews and daily milk production: daily milk production (kg/day) = 0.001935 × mastication chews (chews/day) + 2.103 (R² = 0.34; SE = 8.70; p = 0.007). Overall, the results indicated that the RumiWatch sensor can be confidently used to quantify and differentiate prehension bites, eating chews and rumination chews; in addition, ingestive behaviours explained up to 34% of the variation in milk production. Full article

Milk production from Asiatic swamp buffalo is a new enterprise in Laos. As yields are limited, provision of high-quality cow-calf molasses nutrient blocks containing 10% urea (UMNB10) may improve productivity. A trial in a recently established commercial buffalo dairy examined dietary supplementation of lactating buffalo cows with UMNB10, with three groups of nine cows in mid-lactation randomly selected. Two groups received ad libitum access to UMBs with the remaining group free of block supplements. All animals were daily fed fresh Napier grass (30 kg), corn (750 gm), rice bran (1.45 kg), plus accessed fresh Mulatto grass. Daily milk production (DMP) and body condition score (BCS) were recorded for the 2 months of access to UMB. Average DMP for the two supplemented groups were 1.02 and 0.96 L, compared to 0.78 L for the control group, suggesting improved milk productivity of 31 and 24% from accessing UMB. Partial budget analysis identified a strong incentive for use of the molasses blocks, with a net profit of USD 408 and USD 295 over a 30-day period for the supplemented groups. A multi-intervention livestock development strategy that includes a combination of nutritional and health interventions has been proposed for scale-out to assist smallholder livestock farming efficiency in developing countries. The use of high-quality molasses blocks may be a simple motivator for these communities to increase the efficiency of large ruminant production, improving rural livelihoods, food security, and potentially, reducing greenhouse gas emissions (GHGe) from ruminant-derived foods. Full article

The inverse association between the groups of odd-chain (OCFA) and branched-chain (BCFA) and the development of diseases in humans have generated interest in the scientific community. In experiment 1, the extent of the passage of odd- and branched-chain fatty acids (OBCFA) from milk fat to fresh cheese fat was studied in sheep and goats. Milk collected in two milk processing plants in west Sardinia (Italy) was sampled every 2 weeks during spring (March, April and May). In addition, a survey was carried out to evaluate the seasonal variation of the OBCFA concentrations in sheep and goats’ cheeses during all lactation period from January to June. Furthermore, to assess the main differences among the sheep and goat cheese, principal component analysis (PCA) was applied to cheese fatty acids (FA) profile. Concentrations of OBCFA in fresh cheese fat of both species were strongly related to the FA content in the unprocessed raw milk. The average contents of OBCFA were 4.12 and 4.13 mg/100 mg of FA in sheep milk and cheese, respectively, and 3.12 and 3.17 mg/100 mg of FA in goat milk and cheese, respectively. The OBCFA concentration did no differed between milk and cheese in any species. The content of OBCFA was significantly higher in sheep than goats’ dairy products. The OBCFA composition of the cheese was markedly affected by the period of sampling in both species: odd and branched FA concentrations increased from March to June. The seasonal changes of OBCFA in dairy products were likely connected to variations in the quality of the diet. The PCA confirmed the higher nutritional quality of sheep cheese for beneficial FA, including OBCFA compared to the goat one, and the importance of the period of sampling in the definition of the fatty acids profile. Full article

Practical experience suggests that music can have a positive effect on the welfare of dairy cows, which for some other animal species has been shown in earlier studies. Music could, furthermore, be a useful tool to support, for example, daily milking routines. In this pilot study we explored effects of music inside an automatic milking system (AMS) on cows’ milk yield and behavior. The experiment was conducted on a Finnish dairy farm with 56 cows in loose housing. Over two 2-day periods without and with selected music pieces played inside the AMS, data on daily milk yield (DMY), selection gate passing frequency (GP), milking frequency (MF), and milking interval (MI) were recorded. For analyses, data of 17 Holstein-Friesian cows were used. At cow level, mean values over repeated measurements without and with music were calculated, and analyzed by paired t-tests (DMY, MF) or Wilcoxon tests (MI, GP). During intervals with music versus without, cows passed the selection gate more often (15.8 versus 13.8) and had higher MF (3.0 vs. 2.8). No differences were found in MI (07:49:21 vs. 08:37:38) and DMY (36.5 vs. 37.0). The latter might be explained by a ceiling effect. Overall, the results suggest that the investigated sample of cows perceived the selected music as attractive and that playing music might be a practical tool to reduce necessary efforts of driving cows to milking. Full article

This short communication addresses the hypothesis that the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is low in dairy goats in Sweden. Methicillin-resistant S. aureus is a widespread zoonotic bacterium of clinical importance in both animals and humans. In Sweden, MRSA is rare among both animals and humans. However, MRSA has been detected in a few goat herds in Sweden with a high within-herd occurrence of mecC-MRSA, but only a limited number of herds were investigated and most of them were not producing milk for human consumption. The prevalence of MRSA among dairy goat herds in Sweden is not known and a cross-sectional prevalence study was therefore conducted. A total of 22 bulk milk samples from the same number of herds, and pooled swabs from nose, mouth, and perineum from 113 goats, were collected during August and September 2019 for bacteriological investigation. After culturing on selective media, suspected isolates were confirmed as S. aureus using MALDI-TOF and subjected to PCR targeting the mecA and mecC genes to confirm MRSA status. No samples were found to be positive for MRSA, and there are therefore no indications of a spread of MRSA in Swedish dairy goat herds. Full article

Postpartum uterine diseases are common in dairy cows and are a great concern for the dairy industry as they are associated with various consequences, including lower fertility, lower milk yield, and an overall negative impact on the host health. An infected uterus is a source of bacterial compounds and cytokines that spill into the systemic circulation, spreading inflammation to other organs. In this review article, we discuss a short overview of the anatomy of the reproductive tract of dairy cows and several infectious diseases of the uterus including metritis, endometritis, and pyometra. Additionally, we discuss the microbiome of the reproductive tract in health and during uterine diseases. As well, diagnostic criteria for metritis and endometritis and contributing factors for increased susceptibility to metritis infection are important topics of this review. To better understand how the uterus and reproductive tract respond to bacterial pathogens, a section of this review is dedicated to immunity of the reproductive tract. Both the innate and adaptive immunity systems are also discussed. We conclude the review with a factual discussion about the current treatments of uterine diseases and the new developments in the area of application of probiotics for uterine health. Mechanisms of actions of probiotics are discussed in detail and also some applications to prevent uterine infections in dairy cows are discussed. Full article

The objectives of this study were to examine the effects of varying dietary energy supply as well as the impacts of subclinical ketosis (SCK) on blood chemistry and liver health. A total 63 German-Holstein cows were housed from three weeks antepartum until sixteen weeks postpartum. After calving, cows were assigned to one of four treatment groups receiving either moderate or high energy concentrations in roughage and secondly moderate or high amounts of concentrates. Retrospectively, cows were additionally grouped according to their β-hydroxybutyrate concentration (SK: cows with SCK vs. CON: cows without SCK). The different energy supply of treatment groups had little effects on blood and liver variables; greater differences occurred between SK and CON cows. Liver fat content of SK cows was 34% higher compared to CON cows. Also, the activity of aspartate aminotransferase and γ-glutamyl transferase, bilirubin concentration, and percentage of granulocytes were increased in SK cows. The results indicate that cows were able to adjust their metabolism to different dietary energy supplies without having a clearly increased risks for metabolic disorders. However, individual animals of all groups developed a metabolic derailment during the postpartum period resulting in SCK, which is closely connected with impaired liver function, compromised immune-responsiveness, and elevated oxidative stress. Full article

Examples of niche tourism have emerged in parallel to the growing importance of food tourism in destination management and marketing. Examples of this include mushroom tourism, tea tourism, or udon tourism, among others. This study analyzes one of this specialist forms of food tourism: dairy tourism. Dairy tourism is the leisure and tourist practice that leads to the discovery of production, transformation, and commercialization processes of milk and milk derivatives. Specifically, the objective of this research is to discuss the relationships between local dairy landscapes and tourism in the Catalan region of Empordà, in the northeast of the Iberian Peninsula. Drawing on field visits and interviews with the seven regional producers, results describe the mechanisms of dairy tourism from a local marketing perspective. Full article

During late gestation and early lactation, many proliferative processes and metabolic adaptions are involved in homeorhesis. An adjusted supply of oxygen is a precondition for an optimized cellular energy metabolism whereby erythrocytes play a central role. Endogenous L-carnitine modulates the mitochondrial fatty acid utilization for generating adenosine triphosphate (ATP). As it might be insufficient around calving due to increased need, L-carnitine supplementation is frequently recommended. Thus, the present study addressed the interplay between the red hemogram, platelets, oxidative stress indices, and L-carnitine supplementation of dairy cows around calving. German Holstein cows were assigned to a control (n = 30) and an L-carnitine group (n = 29, 25 g of rumen-protected L-carnitine per cow and per day), and blood samples were taken from day 42 ante partum (ap) until day 110 postpartum (pp), with a higher sampling frequency during the first three days pp. The time courses of the erythrogram parameters reflected the physiological adaptations to the oxygen need without being influenced by L-carnitine supplementation. Erythrocytic antioxidative enzymatic defence paralleled the relative development of polycythemia ap, while non-enzymatic total plasma antioxidative capacity continuously increased pp. In contrast to erythrocytes, the platelet counts of the L-carnitine supplemented cows varied at significantly higher levels. This can be interpreted as a result of a membrane-stabilizing effect of L-carnitine. Full article