Effects of Mastitis on Buffalo Milk Quality

Exploiting machine learning methods with monthly routine milk recording data and climatic information to predict subclinical mastitis in Italian Mediterranean buffaloes

Mastitis has detrimental effects on the world's dairy industry, reducing animal health, milk production and quality, as well as income for farmers. In addition, consumers' growing interest in food safety and rational usage of antibiotics highlights the need to develop novel strategies to improve mastitis detection, prevention, and management. In the present study we applied machine learning (ML) analyses to predict presence or absence of subclinical mastitis in Italian Mediterranean buffaloes, exploiting information collected the previous month during routine milk recording procedures, as well as climatic data. The data set included 3,891 records of 1,038 buffaloes from 6 herds located in Basilicata Region (South Italy). Prediction models were developed using 4 different ML algorithms (Generalized Linear Model, Support Vector Machines, Random Forest, and Neural Network) and 2 data set splitting approaches for the creation of the training and test sets (by record or by animal ID number, always with 80% of the data used for model training and the remaining 20% for model testing). Support Vector Machine was the best method to predict high or low somatic cell count at the subsequent test-day record in the validation set, and therefore it was used to estimate the contribution of each feature to the best model. Independently from the data set splitting approach, the most important features were somatic cell score, differential somatic cell count, electrical conductivity, and milk production. Among climatic data, the most informative were temperature and relative humidity. When the data were split by animal ID, an improvement in models' predictive performance on the test set was observed, suggesting this as the most appropriate data splitting approach in data sets with repeated measures to avoid data leakage. According to different metrics, Neural Network was the best method for making predictions on the test set. Our findings confirmed the promising role of ML methods to improve prevention and surveillance of subclinical mastitis, exploiting the large amount of data currently available to identify animals that would possibly have high somatic cell count the subsequent month.

Summer Buffalo Milk Produced in China: A Desirable Diet Enriched in Polyunsaturated Fatty Acids and Amino Acids

The objective of the study was to compare and reveal differences in basic chemical parameters, fatty acids, amino acids, and lipid quality indices of crossbred buffalo (swamp x river type) milk produced in summer and winter. The buffalo milk samples were collected in summer (Jul-Aug) and winter (Dec-Jan) from Hubei province, China. The samples were detected by using CombiFoss apparatus, gas chromatography, and an automated specialized amino acid analyzer. The results showed that the basic chemical parameters, fatty acid profiles, lipid quality indices, and amino acid profiles of crossbred buffalo milk differed between summer and winter. Specifically, summer buffalo milk exhibited a higher content of MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids) than winter buffalo milk. Summer buffalo milk had a lower content of major SFA (saturated fatty acids), a higher content of ω-3 and DFA (hypocholesterolemic fatty acids), a lower ω-6/ω-3 ratio, a higher value of 3 unsaturated fatty acid indices (C14, C16, C18), and a lower value of IA (index of atherogenicity) and IT (index of thrombogenicity) than winter buffalo milk. Additionally, 17 amino acids, including 8 EAA (essential amino acids) and 9 NEAA (non-essential amino acids) were higher in summer buffalo milk. These results indicated that summer buffalo milk was more health-beneficial than winter buffalo milk. Therefore, summer buffalo milk might be a desirable diet option for human nutrition and health. Our findings provide valuable information for the research and development of buffalo dairy products in China or other Asian countries.

Effect of Antioxidant Supplementation on Milk Yield and Quality in Italian Mediterranean Lactating Buffaloes

Buffaloes are raised mainly to obtain milk that is nutritionally very rich. The technological characteristics of buffalo milk are optimal for processing into cheese, and it is mainly used to produce mozzarella cheese. Under stressful conditions, buffaloes, like other animals, produce milk qualitatively poorly. The stressors that can affect the quality of production are, in addition to other factors, deficiencies in nutrients such as vitamins, antioxidants, and minerals. In this study, we evaluated the effect of antioxidant supplementation on the quality of buffalo milk. Sixty-six buffaloes were enrolled and subdivided into two balanced groups of 33 each. The ZnSe group received 0.2 kg/head/day of Bufalo Plus® containing antioxidants and barley meal, CaCO3 and MgCO3 mix; the control group was supplemented with 0.2 kg/head/day of barley meal, CaCO3 and MgCO3 mix. The two groups were fed ad libitum with a total mixed ration (TMR). The amount of diet distributed was recorded daily, and the residue in the trough manger was recorded three times per week. TMR samples were taken every two weeks for each group. Daily milk yield was recorded twice a week. Milk samples were collected every four weeks and analysed for chemical and technological properties. Furthermore, milk total antioxidant capacity was determined. The results obtained showed that the antioxidant supplement had no effect on feed intake, feeding behaviour, and feed efficiency. The treatment positively influenced milk production while it did not affect the chemical characteristics of the milk. In addition, the supplement of antioxidants improved the milk clotting properties (MCP). The supplement did not affect the antioxidant activity of the milk.

Relationship Between Somatic Cell Counts and Mammary Gland Parenchyma Ultrasonography in Buffaloes

The aim of the present study was to determine whether the echotextural features of the mammary gland parenchyma in buffaloes during lactation at different somatic cell levels could be used to diagnose mastitis. This study was divided into two parts. In the first experiment, experimental buffaloes (n = 65) with somatic cell counts (SCC) tests (n = 94) in different seasons, including spring (n = 22), summer (n = 24), autumn (n = 37), and winter (n = 11), were used to obtain ultrasonic variables for each quarter of mammary gland that could best explain the corresponding somatic cell level. In the second part of the study, the first part's experimental results were verified by subjecting at least one-quarter udder of eight buffaloes to ultrasonography seven times during mid-July to mid-August for obtaining ultrasonic values at different somatic cell levels. The echo textural characteristics [mean numerical pixel values (NPVs) and pixel heterogeneity (pixel standard deviation, PSD)] were evaluated using 16 ultrasonographic images of each buffalo with Image ProPlus software. The effects of SCC, days in milk (DIM), scanning order (SO), season, as well as the scanning plane and udder quarter (SP + UQ) on both the PSD and NPVs of the mammary gland were significant (p < 0.05). The correlation coefficient between pre-milking sagittal PSD and somatic cell score (SCS) was the highest (r = 0.4224, p < 0.0001) with fitted linear model: y = 0.19445x (dependent variable: SCS, independent variables: pre-milking sagittal PSD; R² = 0.84, p < 0.0001). In addition, SCC and ultrasonic of udder quarter were followed for 1 month, confirming that pre-milking sagittal PSD of mammary gland value could explain the SCC variation in milk. The current study demonstrated that the ultrasonographic examination of the udder could be one of the complementary tools for diagnosing subclinical mastitis in buffaloes.

Dynamics of Macrophages and Polymorphonuclear Leukocytes Milk-Secreted by Buffaloes with Udders Characterized by Different Clinical Status

The study evaluated the dynamics of macrophages and polymorphonuclear leukocytes milk-secreted by Mediterranean Buffaloes (MBs). Sixty quarter-milk-samples were collected and divided into three groups (n = 20 units each one): clinical mastitis (CM), subclinical mastitis (SCM), and intramammary infection (IMI). The control group consisted of an additional 20 healthy quarters. Their health status was assessed by clinical examination, quantitative somatic cell count (QSCC) and bacteriological milk culture. Finally, a differential somatic cell count (DSCC) was performed on all the milk samples. The mean percentage of macrophages, both in CM- and SCM-quarters, showed a significant difference as compared with the healthy-ones. Significant differences were also detected comparing the mean percentages of polymorphonuclear leukocytes between CM- and healthy-quarters, SCM and healthy, IMI and healthy. The QSCC revealed a weak-significant-negative-correlation with the quantitation of macrophages (r = −0.388), and a moderate-significant-positive-correlation with the polymorphonuclear leukocytes (r = 0.477). Macrophages and polymorphonuclear leukocytes showed a weak-significant-negative-correlation between them (r = −0.247). The interpretation of macrophages and polymorphonuclear leukocytes dynamics in milk provided beneficial information regarding the clinical status of the quarters enrolled. Future studies exploring the potential use of DSCC to improve udder health represent an interesting perspective in these ruminants.

Microbiological and physicochemical characteristics of buffalo milk used for dairy products in southern Brazil

In Brazil, the buffalo milk market has been growing. However, identity and quality standards have not been established for this raw material, nor have proper distinctions between buffalo milk and bovine milk been defined. Currently, the State of Rio Grande do Sul (RS) has only three producers that supply raw material for officially marketed derivatives. The aim of this study was to determine the identity and quality standards of raw buffalo milk in this region. Samples were obtained biweekly from three farm cooling tanks between June 2017 and August 2018, to reach a total of 69 samples. The averages for the results of the physicochemical parameters fat, protein, lactose, total solids, SNF (solids-not-fat), calcium, density, FP, acidity and SCC were 5.5 g/100 g, 4.06 g/100 g, 5.07 g/100 g, 15.5 g/100 g, 9.96 g/100 g, 0.161 g/100 g, 1.034 g/ml, -0.527°C, 16°D and 95 × 103 cells/ml, respectively. With reference to the microbiological parameters, the mean of the Standard Plate Count (SPC) and thermotolerant coliforms were 9,0 × 104 CFU/ml and 1.6 × 102 MPN/ml, respectively. Regarding coagulase-positive staphylococci, 36 samples tested positive (52% of total). Neither Salmonella spp. nor Listeria monocytogenes, nor antibiotic or antiparasitic residues were detected in any sample. In conclusion, the buffalo milk used as raw material for dairy products in southern Brazil demonstrated satisfactory physicochemical and microbiological characteristics, in accordance with recent scientific literature.

Milk somatic cell count and its relationship with milk yield and quality traits in Italian water buffaloes

In Southern Italy, buffalo (Bubalus bubalis) milk is mostly intended for the manufacture of Mozzarella di Bufala Campana Protected Denomination of Origin (PDO) cheese. Despite the economic boost of the last 2 decades, the buffalo farming system should be improved to maximize the efficiency of the dairy industry, improve yield and quality of milk and cheese, and work toward better animal welfare. Milk somatic cell count (SCC) is used worldwide as an indicator of udder health in individual milk and is useful for monitoring farm hygiene in bulk milk. Mastitis data are currently not available on a large scale in Italy; thus, SCC is essential for identifying animals with suspected udder infection and inflammation. Moreover, high milk SCC is associated with altered composition and acidity, and poor technological properties of milk. However, payment systems of the PDO area are based simply on the delivered volume of milk rather than on quality characteristics. Hence, currently there are no penalties for elevated SCC in bulk milk in the Italian buffalo dairy industry. In addition, SCC for buffalo milk is not mentioned by either the European Community regulations or the PDO protocol, evidencing a lack of rules for the maximum SCC limit. To provide a phenotypic characterization of SCC at the population level and to improve knowledge on buffalo milk quality, 876,299 test-day records of 70,156 buffaloes reared in the PDO area were analyzed. Data revealed that around 11% of herd-test-dates (≥5 animals sampled each) showed average milk SCC ≥400,000 cells/mL (i.e., above the threshold fixed by the European Community for bovine milk). This suggests that there is room to improve SCC at both the farm and individual level. Within first parity, more than 28 and 15% of lactations had average SCC ≥200,000 and ≥300,000 cells/mL, respectively. Both percentages increased with parity and were 39 and 25% in sixth parity, respectively. Supporting this, the proportion of lactations with average SCC ≥500,000 cells/mL increased from 6% in first parity to 12% in sixth parity. Milk yield and SCC were negatively correlated with each other, especially when SCC level was high. An ANOVA was carried out on test-day record milk yield and composition traits, with fixed effects of parity, lactation stage, class of somatic cell score (n = 6), month of calving, and their interactions; buffalo, herd-test-date, and residual were considered random effects. Significantly lower milk yield and lactose percentage were estimated in progressively higher classes of somatic cell score, whereas no significant differences were observed for fat and protein percentages. This is the first attempt to investigate milk SCC in a large data set of Italian dairy buffaloes. These findings may be helpful for defining reliable and effective SCC thresholds to be adopted whenever specific penalties for high SCC are included in milk payment systems. Finally, these results could be used in mastitis monitoring plans aiming to reduce SCC and udder issues at both the individual and farm levels in the Italian buffalo population.

Phenotypic Characterization of Milk Yield and Quality Traits in a Large Population of Water Buffaloes

Simple Summary

The buffalo dairy industry has deep roots in Southern Italy, due to the traditional link with Mozzarella di Bufala, a Protected Designation of Origin cheese with high economic value and market demand. At farm level, strategies aiming to improve milk yield and quality are essential to maximize profitability and dairy chain efficiency. In this study, we analyzed a large data set of Italian Buffaloes (around 70 thousands animals) in order to detect the phenotypic sources of variation of milk yield and quality traits, disclose exploitable favorable correlations among milk traits, and provide useful information for dairy buffalo chain stakeholders.

Abstract

The buffalo milk industry has economic and social relevance in Italy, as linked to the manufacture of traditional dairy products. To provide an overview of the current status of buffaloes’ performances on a large scale, almost 1 million milk test-day records from 72,294 buffaloes were available to investigate milk yield, energy corrected milk, fat, protein, and lactose content, and somatic cell score (SCS). Phenotypic correlations between milk traits were calculated and analysis of variance was carried out through a mixed model approach including fixed effect of parity, stage of lactation, sampling time, month of calving, and all their interactions and random effects of buffalo, herd-test-date, and residual. Third-parity buffaloes were the most productive in terms of milk yield, while the lowest solid content was detected in sixth parity buffaloes. A considerable gap between primiparous and multiparous buffaloes was observed for milk yield, especially in early- and mid-lactation. Overall, SCS progressively increased with parity and showed a negative correlation with milk yield in both primiparous (−0.12) and multiparous (−0.14) buffaloes. Results suggested that, at the industrial level, milk of primiparous buffaloes may be preferred for transformation purposes, since it was characterized by greater solid content and lower SCS. Results of this study provide a picture of the Italian population of buffaloes under systematic performance records and might be beneficial to both dairy industry and breeding organizations.

Histopathological and microbiological findings in buffalo chronic mastitis: evidence of tertiary lymphoid structures

Buffalo mastitis is an important economic problem in southern Italy, causing qualitative/quantitative alterations in milk and resulting in economic losses due to the sub-clinical course and chronic evolution. We investigated 50 udders of slaughtered buffaloes and subjected them to effectual microbiological screening to evaluate macro and microscopic mammary gland changes, immune-characterize the cell infiltrates, and compare the degree of tissue inflammation with somatic cell counts. Numerous Gram-positive and Gram-negative bacteria were isolated from all samples, majority of which were environmental mastitis pathogens. Histological features referable to chronic mastitis were observed in 92% udders. Lymphocytes, plasma cells and macrophages were found to evolve into aggregates in 48% udders, which often organized to form tertiary lymphoid structures (TLSs). A predominance of interstitial CD8+ over CD4+ lymphocytes and, in TLSs, scattered CD8+ lymphocytes in the mantle cells and CD79+ lymphocytes in germinal centers, were evidenced. Environmental pathogens are known to persist and cause chronic inflammatory changes in buffaloes, where CD8+ lymphocytes play an important role by controlling the local immune response. Moreover, the TLSs evidenced here for the first time in buffalo mastitis, could play a role in maintaining immune responses against persistent antigens, thereby contributing in determining the chronic course of mastitis.

Factors Contributing to the Decline of Traditional Practices in Communities from the Gwallek-Kedar area, Kailash Sacred Landscape, Nepal

Traditional knowledge and practices are increasingly recognized in the resource conservation and management practices, however are declining in many parts of the world including Nepal. Studies on the inventory of traditional knowledge are available, albeit limited, and empirical analysis of factors contributing to the decline of traditional knowledge are negligible in Nepal. We thus initiated this study in the Nepal part of the Kailash Sacred Landscape to (i) document traditional knowledge and practices on agriculture, forest-based herbal remedy, and genetic resource conservation; and (ii) identify factors contributing to the decline of traditional practices in the communities. Data was collected during September-December 2015 through key informant interviews, focus group discussions, and households survey. The household survey data was used in binary logistic regression analysis to identify factors contributing to the decline of six key traditional practices. The study documented 56 types of traditional practices. The regressions showed that the age of the respondent, distance to the nearest forest, distance to the nearest motorable road, family members' ill health, and seasonal migration of the household members for jobs significantly influencing to the decline of the particular traditional practices, however, their effects vary within a practice and among the practices. The use of modern medicine, increasing road linkages, decreasing trend of plant resource availability, and agriculture intensification are responsible for the decline of the particular traditional practices. We recommend to recognize their significance in the governing socio-ecological systems and to link the traditional and scientific knowledge systems through policy formulations.

Recognition of Somatic Cells in Bovine Milk Using Fusion Feature

Mastitis is the major cause of loss in dairy farming. Somatic cells are one of most important standards to detect this infection. This paper proposes a novel image processing algorithm to recognize four types of somatic cells in bovine milk automatically. First, cloud model uses to segment cell images. Second, a variety of features are extracted from regions of interest. Finally, most differential features are selected using ReliefF algorithm and performances of two classifiers, Back propagation networks (BPN) and support vector machine (SVM), are compared. The experimental results are obtained using a large set of images from different sources. The results of our proposed method is not only efficient in accuracy and speed, but also robust to illumination in bovine mastitis via optical microscopy.

Mastitis outcomes on pre-ovulatory follicle diameter, estradiol concentrations, subsequent luteal profiles and conception rate in Buffaloes

The objectives of this study was to investigate the outcome of mastitis, in its clinical or subclinical forms, on the mean diameter of pre-ovulatory follicle (POF), plasma estradiol concentration on the day of estrus, subsequent luteal profile and subsequent conception rate in buffaloes. Sixty dairy buffalo (Bubalus bubalus) conducted in this study were divided into three groups {healthy (H), n=20; subclinical mastitis (SCM), n=18; and clinical mastitis (CM), n=22}. Ultrasonography of ovaries revealed that mean diameter of POF was larger (P<0.05) in H buffalo (14.35mm) compared to SCM (12.40mm) and CM (10.25mm). Also, plasma estradiol concentration on the day of estrus was higher (P<0.05) in H buffalo compared to SCM and CM counterparts; 34.95 vs. 32.87 and 27.50pg/ml, respectively. Besides, positive correlation was observed between the POF diameter with plasma estradiol concentration in H, SCM and CM buffaloes (r=0.64, 0.74, 0.72 respectively, P<0.05). Moreover, positive correlations (P<0.01) were found on days 9, 12, 16, and 21 post-ovulation between POF diameter and luteal profile. Thus, the conception rate in H buffalo was higher (P<0.05) compared with SCM and CM counterparts; 55% vs. 38.89 and 18.18%, respectively. In conclusion, mastitis in its clinical or subclinical forms disrupts the functioning of the pre-ovulatory follicle on the day of estrus, associated with low follicular estradiol production, resulting in suppression to subsequent luteal profile leading to substantial decrease in pregnancy consequence of buffaloes.

Estimation of Mineral and Trace Element Profile in Bubaline Milk Affected with Subclinical Mastitis

The milk samples from buffaloes of Murrah breed at mid lactation stage, reared at an organised dairy farm, were screened for subclinical mastitis based on bacteriological examination and somatic cell count following International Dairy Federation criteria. Milk samples from subclinical mastitis infected and healthy buffaloes were analysed to evaluate physicochemical alterations in terms of protein, fat, pH, electrical conductivity, chloride, minerals (sodium, potassium and calcium) and trace elements (iron, zinc, copper and selenium). In the present study, protein, fat, zinc, iron, calcium and selenium content was significantly lower (P < 0.001), while pH and electrical conductivity were significantly higher in mastitic milk as compared to normal milk. Concentration of electrolytes mainly sodium and chloride significantly increased with higher somatic cell count in mastitic milk and to maintain osmolality; potassium levels decreased proportionately. Correlation matrix revealed significantly positive interdependences of somatic cell count with pH, electrical conductivity, sodium and chloride. However, protein, fat, calcium and potassium were correlated negatively with elevated somatic cell count in mastitic milk. It is concluded that udder infections resulting in elevated somatic cells may alter the mineral and trace element profile of milk, and magnitude of changes may have diagnostic and prognostic value.

Efficacy of a polyvalent mastitis vaccine against Staphylococcus aureus on a dairy Mediterranean buffalo farm: results of two clinical field trials

Background

In the last years the knowledges on Mediterranean Buffalo (MB) mastitis is remarkably improving, nevertheless the attention has been never focused on vaccination as preventive strategy for the control of mastitis in these ruminates. The aim of the current study was to assess clinical efficacy over time of two different preventive vaccination protocols against S. aureus mastitis, in primiparous MB.Vaccinated (VG) and not-vaccinated (N-VG) groups, of 30 MB each one, were selected from two different herds (herd A: VG1 and N-VG1; herd B: VG2 and N-VG2) of the same farm. Herd A received a double vaccination (Startvac®, 45 and 10 days before calving, protocol A), while in herd B an additional administration was performed (52 days after calving, protocol B). Bacteriological milk culture and assessment of somatic cell count (SCC) were performed at 10, 30, 60 and 90 days in milk (DIM) from composite milk samples. After 90 DIM, daily milk yields and SCC values were monthly detected until dry-off.

Results

The overall incidence of positive MB for S. aureus was 40.8% (49/120) in VG1 and 43.3% (52/120) in N-VG1 (Protocol A), while 45.8% (55/120) and 50.8% (61/120) in VG2 and N-VG2 (Protocol B). The latter was associated with a significant decreased in prevalence (at 90 DIM) and incidence of mastitis (animals positive for S. aureus, SCC > 200^10³, with or without clinical signs) in the vaccinated MB, while no difference occurred in protocol A. Moreover, herd B showed a significant reduction in prevalence of intramammary infection (animals positive for S. aureus, SCC < 200^10³, no clinical signs) in the vaccinated MB at 60 DIM while no differences were detected in herd A, at any sampling time; N-VG2 had significantly higher overall SCC values than VG2 (4.97 ± 4.75 and 4.84 ± 4.60 Log10 cells/mL ± standard deviation, respectively), while no differences were recorded in herd A.

Conclusions

The current investigation explores for the first time the clinical efficacy of vaccinations against S. aureus infections in MB, showing encouraging results regarding reduction in mastitis and somatic cell count; the polyvalent mastitis vaccine may be considered an additional tool for in-herd S aureus infection and should be associated to other control procedures to maximize its properties.

Aspectos clínicos e laboratoriais da mastite induzida por inoculação intramamária de Staphylococcus aureus em vacas e búfalas

Vários aspectos relacionados à mastite bubalina precisam ser esclarecidos. Muitas condutas são adaptadas a essa espécie pelo conhecimento adquirido com a espécie bovina. Com este experimento, objetivou-se evidenciar particularidades da mastite em búfalas e vacas que tiveram uma glândula inoculada com 1,0 x 103 UFC de S. aureus. Os animais foram monitorados por cultura bacteriana do leite, California Mastitis Test(CMT), e escores para avaliação da severidade da mastite. Foram utilizados os seguintes critérios: temperatura retal, apetite, produção de leite (resposta sistêmica à inflamação), contagem de células somáticas (CCS), aparência/consistência da glândula e aparência da secreção láctea (resposta localizada à inflamação). Todos os animais desenvolveram mastite clínica superaguda. A bactéria foi recuperada de todas as glândulas desafiadas, sem diferença significativa no percentual de isolamento entre as espécies até o 11º dia pós-inoculação, porém com diferença (P<0,001) no 30º dia pós-inoculação. A CCS pelo método eletrônico e o CMT detectaram nas búfalas resposta mais intensa logo após a inoculação e diminuição mais rápida da contagem ao final do experimento, quando se comparou essa espécie com as vacas. Ambos os testes demonstraram correlação com a cultura bacteriana. Na avaliação da severidade da mastite, as médias do escore total, do escore da resposta local e do escore da resposta sistêmica foram mais elevadas na espécie bovina (P<0,05). Ao longo do período de observação, verificou-se uma capacidade superior das búfalas em recuperar o status sanitário adequado, chegando, ao final do experimento, com os parâmetros avaliados mais próximos dos fisiológicos.