Individual Milk Samples Research Articles

Influence of sampling technique and bedding type on the milk microbiota: Results of a pilot study

The objective of this pilot study was to evaluate the influence of sampling technique and exposure to different bedding types on the milk microbiome of healthy primiparous cows. Primiparous Holstein cows (n = 20) with no history of clinical mastitis or monthly somatic cell counts >150,000 cells/mL were selected for this study. From each enrolled cow, a composite milk sample was aseptically collected from all 4 mammary quarters (individual quarter somatic cell counts <100,000 cells/mL), 1 individual quarter milk sample was collected using conventional aseptic technique, and 2 individual quarter milk samples were collected directly from the gland cistern using a needle and vacuum tube. All milk samples were cultured using standard milk microbiological techniques and DNA was extracted. Extracted DNA was subjected to PCR and next-generation sequencing for microbiota determination. All samples yielded relatively little total DNA. Amplification of PCR was successful in 45, 40, and 83% of composite, conventional, and cisternal samples, respectively. Bacteria were successfully cultured from 35% of composite milk samples but from none of the quarter milk samples collected using conventional or cisternal sampling techniques. Bacterial DNA sequences were assigned to operational taxonomic units (OTU) based on 97% sequence similarity, and bacterial richness and diversity were determined. Most samples were dominated by low-prevalence OTU and of the 4,051 identified OTU, only 14 were prevalent at more than 1% each. These included bacteria typically recovered from environmental sources. Chao richness was greatest in composite samples and was 636, 347, and 356 for composite, conventional quarter, and cisternal milk samples, respectively. Shannon diversity was similar among sample types and ranged from 3.88 (quarter) to 4.17 (composite). Richness and diversity did not differ by bedding type among cisternal samples, but the power of this pilot study was limited due to small sample size. Despite the small sample size, for milk samples collected from the gland cistern, overall bacterial community composition differed among bedding types. These results demonstrate that sampling technique and bedding type may be associated with the microbiota detected in bovine milk, and we suggest that these variables should be considered in designing and reporting studies about the milk microbiota.

Short- and long-term association between individual levels of milk antibody against Ostertagia ostertagi and first-lactation heifer’s production performances

It is agreed that exposure of adult dairy cattle to helminths on pasture can negatively affect production performances as milking herd. Young animals, especially replacement heifers, represent the future of a dairy farm and are among the most vulnerable to helminth infections in a dairy herd. For this reason, dairy farmers tend to frequently treat heifers against helminths, although the impact of helminths on heifers’ production performances is still poorly understood. Using different epidemiological and serological tools, this study examines the relationship between heifer exposure to helminths on pasture and production performances over time. During a one-year period, 1,454 individual milk samples were collected from first-lactation heifers in England and tested for Ostertagia ostertagi (O. ostertagi) antibodies. After controlling for other confounders, increasing milk antibody levels against O. ostertagi were significantly associated with decreased milk yield at sampling but not at day 305 of heifer lactation. We did not observe any relationship between milk antibody levels against O. ostertagi in heifers and yields in fat and protein. However, heifers with a high level of milk antibodies against O. ostertagi were more likely to produce dead calf at first calving and present a delay in second calving. Moreover, these heifers had significantly higher levels of milk antibodies against Mycobacterium paratuberculosis (M. paratuberculosis) during their first lactation and were more likely to die before the end of the study. We argue that epidemiological approaches can be useful but must be complemented by other methodologies to better understand the impact of helminth infections in dairy heifers. In order to address the complex dynamics of helminth infections in dairy cattle production we require more comprehensive approaches that include triangulation between data sources and interdisciplinary studies.

Polymorphism at donkey β-lactoglobulin II locus: identification and characterization of a new genetic variant with a very low expression.

In the last years, donkey milk had evidenced a renewed interest as a potential functional food and a breast milk substitute. In this light, the study of the protein composition assumes an important role. In particular, β-lactoglobulin (β-LG), which is considered as one of the main allergenic milk protein, in donkey species consists of two molecular forms, namely β-LG I and β-LG II. In the present research, a genetic analysis coupled with a proteomic approach showed the presence of a new allele, here named F, which is apparently associated with a null or a severely reduced expression of β-LG II protein. The new β-LG II F genetic variant shows a theoretical average mass (Mav) of 18,310.64Da, a value practically corresponding with that of the variant D (∆mass < 0.07Da), but differs from β-LG II D for two amino acid substitutions: Thr100 (variant F) → Ala100 (variant D) and Thr118 (variant F) → Met118 (variant D). Proteomic investigation of the whey protein fraction of an individual milk sample, homozygous FF at β-LG II locus, allowed to identify, as very minor component, the new β-LG II F genetic variant. By MS/MS analysis of enzymatic digests, the sequence of the β-LG II F was characterized, and the predicted genomic data confirmed.

Characterization of the nongenetic causes of variation in the calcium content of bovine milk on French farms

Milk is an important source of Ca in Western diets. Milk Ca is important for the cheesemaking process and could be a useful biomarker of Ca regulation in cows. The objective of this study was to identify and quantify nongenetic factors affecting the variation of Ca content in bovine milk. During the PhénoFinLait program, a survey was performed in 3 major areas of milk production in France. This survey consisted of collecting milk samples, together with information about herd management and cow nutrition, from 924 commercial farms. More than 200,000 individual milk samples were collected, and Ca content was measured by mid-infrared spectroscopy. Each farm was surveyed several times during the year, and 3 to 6 milk samples were collected from each cow. An equation to predict milk Ca content from mid-infrared spectra was developed based on the Ca contents of 292 milk samples, and the milk Ca contents of the 200,000 samples were then predicted. Milk Ca content was lowest in Holstein cows, intermediate in Montbéliarde cows, and highest in Normande cows. For all 3 breeds, milk Ca decreased during the first month of lactation and increased after the fourth month of lactation, with the range between minimum and maximum values largest in Holsteins, intermediate in Montbéliardes, and smallest in Normandes. Milk Ca content also decreased with parity in all 3 breeds. By using multiple factorial analysis, 6 major feeding strategies employed on French dairy farms were characterized based on the data from the survey. Calendar month and cow feeding strategy affected milk Ca content, which dropped in the spring during grazing turnout and was lower when cows were fed fresh and conserved grass rather than corn silage. In conclusion, environmental factors induce variations in milk Ca content in addition to the genetics of the cows, which to date have been identified as a main factor of variation of milk Ca content in dairy cows. In several of the tested conditions, increases in milk production and in the amount of Ca daily secreted in milk were associated with a decrease in milk Ca content as though the mammary gland operated to limit the exportation of Ca when milk production rapidly increased. This result would suggest that milk Ca content could be a biomarker of Ca regulation in dairy cows.

Nutritionally Desirable Fatty Acids Including Cla of Cow's Milk Fat Explained by Animal and Feed Factors

This study evaluated the effects of four factors (breed, parity, month of lactation and feeding ration) on the total explained variation (R2) determining composition of nutritionally important fatty acids. Individual milk samples were collected four times over an entire year (March, June, September, and December, respectively) on a conventional farm from two breeds: Czech Fleckvieh (dual-purpose, local) and Holstein (dairy, worldwide). In total, 145 samples (36; 38; 35 and 36, respectively) were analysed. Within the R2, feeding ration and month of lactation were the main factors affecting milk fatty acids composition, whereas breed and parity showed a low effect. A high percentage of the R2 was observed in rumenic acid (52 %), for example, whereas a low percentage was observed in both palmitic acid (30 %) and oleic acid (30 %). This may be due to intra-breed variability affected by different genetic predisposition of each cows, their performance or individual response to changes in feeding ration.

Impact of somatic cell count and lameness on the production and composition of ewe's milk

High somatic cell count (SCC) in milk and lameness are two very serious problems on the farms. The aim of the study was to evaluate the impact of lameness, SCC, month and order of entry into the milking parlour on the milk production and its composition. The relationship between lameness and SCC and their impact on the order of entry was also evaluated. The experiment was carried out at the farm, located in northern Slovakia. The farm keeps sheep crossbred of Improved Valachian and Lacaune. Milking was performed two times a day in milking parlor 1x24. Samples of milk were taken once a month by evening milking: May, July. In May, individual milk samples were taken from 214 random sampling ewes with milk yield minimum 300 mL per milking. In July, only from selected ewes in May, the milk samples, milk yield and lameness were recorded. Order of ewes entry into the milking parlour in milking row (one milking row is 24 animals) was recorded in both months. In total 23 milking rows were recorded. Ewes was divided by lameness (non-lame, slightly lame, strong lame), by SCC (A1 = to 2x105 cells, A2 = from 2x105 to 4x105 cells, A3 = from 4x105 to 7x105 cells, A4 = from 7x105 to 10x105 cells, A5 = over 10x105 cells.mL-1) and by the order of entry of ewes into the milking parlour (in first group of ewes were milked in 1-5 rows, second 6-11, third 12-17, fourth 18-23 ones). No effect of lameness was found out on milk yield. Lameness in July affected the order of entry into milking parlour in July as compared with their order of entry recorded in May. The strong lame ewes entered 4.19 ±1.07 milking rows later in July than in May. Only 11.2% and 4.2% of milk samples were found out in a group with SCC &gt;10x105 cells.mL-1 during May and July respectively. In both months, the production of lactose was lower in groups with higher SCC. Ewes entering into the milking parlour earlier had higher SCC as ewes entering into milking parlour later in July but no effect was seen in May. In conclusion the studies under practical conditions deserve continuous research attention to identify risk factors of management affecting lameness and udder health for further improvement of sheep breeding.

Phenotypic and genetic relationships between indicators of the mammary gland health status and milk composition, coagulation, and curd firming in dairy sheep

The present study investigated the effect of somatic cell count, lactose, and pH on sheep milk composition, coagulation properties (MCP), and curd firming (CF) parameters. Individual milk samples were collected from 1,114 Sarda ewes reared in 23 farms. Milk composition, somatic cell count, single point MCP (rennet coagulation time, RCT; curd firming time, k20; and curd firmness, a30, a45, and a60), and CF model parameters were achieved. Phenotypic traits were statistically analyzed using a mixed model to estimate the effects of the different levels of milk somatic cell score (SCS), lactose, and pH, respectively. Additive genetic, herd, and residual correlations among these 3 traits, and with milk composition, MCP and CF parameters, were inferred using a Bayesian approach. From a phenotypic point of view, higher SCS levels caused a delayed gelification of milk. Lactose concentration and pH were significant for many milk quality traits, with a very intense effect on both coagulation times and curd firming. These traits (RCT, RCT estimated using the curd firming over time equation, and k20) showed an unfavorable increase of about 20% from the highest to the lowest level of lactose. Milk samples with pH values lower than 6.56 versus higher than 6.78 were characterized by an increase of RCT (from 6.00 to 14.3 min) and k20 (from 1.65 to 2.65 min) and a decrease of all the 3 curd firmness traits. From a genetic point of view, the marginal posterior distribution of heritability estimates evidenced a large and exploitable variability for all 3 phenotypes. The mean intra-farm heritability estimates were 0.173 for SCS, 0.418 for lactose content, and 0.206 for pH. Lactose (favorably), and SCS and pH (unfavorably), at phenotypic and genetic levels, were correlated mainly with RCT and RCT estimated using the curd firming over time equation and scarcely with the other curd firming traits. The SCS, lactose, and pH were significantly correlated with each other's. In conclusion, results reported in the present study suggest that SCS, pH, and lactose affect, contemporarily and independently, milk quality and MCP. These phenotypes, easily available during milk recording schemes measured by infrared spectra prediction, could be used as potential indicators traits for improving cheese-making ability of ovine milk.

Effect of farming system on donkey milk composition.

Donkey milk is considered as a functional food for sensitive consumers, such as children who are allergic to cow milk. No information is available regarding the effect of farming systems on the quality of donkey milk. The present study aimed to evaluate the effect of the farming system and lactation stage on donkey milk with respect to gross composition, as well as fat-soluble vitamins and fatty acids (FA). Individual milk samples were collected from lactating jennies (n = 53) on the six of the largest farms located in North West Italy. The performance of lactating jennies, herd characteristics and feeding strategies were recorded at each milk sampling. The gross composition of the milk, along with the fat-soluble vitamin content, differed in accordance with the farming system. The lactation stage had limited effects on milk quality. A higher milk fat content corresponded to a higher amount of fresh herbage proportion in the diet, with the highest polyunsaturated fatty acid (PUFA), C18:1c9, C18:3n-3, n-3 FA, retinol and α-tocopherol content and the lowest concentrations of the FA that are less favorable for human health in the milk of animals fed on only forage diets. Extensive farming of dairy donkeys increased the fat content and fat-soluble vitamin concentration of milk and also altered the FA composition to a more favorable profile for human nutrition. © 2017 Society of Chemical Industry.

The effect of patent Dictyocaulus viviparus (re)infections on individual milk yield and milk quality in pastured dairy cows and correlation with clinical signs

BackgroundInfections with the bovine lungworm Dictyocaulus viviparus might lead to reduced milk production and detrimental impacts on milk quality resulting in considerable economic losses in dairy farming.MethodsIn the presented field study, 1988 faecal samples were collected from 1166 Black and White dairy cows allocated in 17 small and medium-sized German grassland farms. Faecal samples were collected in summer and autumn 2015 to assess D. viviparus larvae excretion. Test-day records were used to estimate the association between patent D. viviparus infections in individual cows and the milk production parameters milk yield, milk protein and milk fat content by using linear mixed models. Bulk tank milk (BTM) samples from each farm and individual milk samples from those cows which were excreting larvae in summer were collected in autumn. In addition, occurrence of the clinical symptom “coughing” was noted in individual cows during autumn sampling to determine its association with patent lungworm infections.ResultsPatent D. viviparus infections were found on 23.5% (4/17) of farms with a prevalence at the individual cow level of 0.9% (9/960) in summer and 3.4% (35/1028) in autumn. No BTM sample exceeded the BTM ELISA cut-off value of 0.410 optical density ratio (ODR), the mean value was 0.168 ODR. Only one individual milk sample exceeded the individual milk ELISA cut-off value of 0.573 ODR (mean value of 0.302 ODR). A patent D. viviparus infection status was associated with a lower average daily milk yield of 1.62 kg/cow/day (P = 0.0406). No significant association was found with milk protein or fat content representing milk quality parameters. Coughing was observed in 5.9% (61/1028) of cows. Of the coughing cows, only 4.9% (3/61) had a patent lungworm infection. Fisher’s exact test showed no significant difference between infected and non-infected coughing cows.ConclusionsFarmers and veterinarians should be aware that patent lungworm (re)infections in dairy cows reduce milk yield, despite the absence of clinical signs. Furthermore, if dairy cows present with coughing, other differential diagnoses need to be considered in addition to dictyocaulosis.

Improving the Quality of Milk Fatty Acid in Dairy Cows Supplemented with Soybean Oil and DHA-Micro Algae in a Confined Production System

The objective was to reduce saturated fatty acids (SFA) and increase conjugated linoleic acid (CLA, cis-9, trans-11 C18:2), α-linolenic (cis-9, cis-12, cis-15 C18:3) and docosahexaenoic (DHA, C22:6) contents in milk from confined dairy cows in order to promote a healthier option. The work was carried out in a commercial farm (Talar) located in Laguna del Sauce, Maldonado (Uruguay). Twenty four cows were assigned to one of two treatments (12 cows per treatment) over a 6 weeks experimental period. Treatments consisted in a control total mixed ration (C-TMR) without supplementary lipids (L) or the same TMR with the addition of 0.144 kg/cow·day of algae and 0.72 kg/cow·day of soybean oil (L-TMR). Chemical composition of the TMR (44.27% DM) averaged 15.94% for crude protein (CP), 38.20% neutral detergent fiber (NDF), 20.36% acid detergent fiber (ADF), 5.56% fat, 5.30% ash and 28.6% nonstructural carbohydrate (NSCH) with 1.81 Mcal/kg of net energy for lactation (NEL). After 39 days of feeding, individual milk samples were collected during three consecutive days. From the total milk collected, 20 ml were immediately used for chemical composition (Milko Scan) and 80 ml for analysis for milk FA profile. From week 3 onwards, milk production (kg/cow·day) resulted higher (P < 0.001) in L-TMR (36.9) compared to C-TMR (35.2). At week 6 of trial, the difference in milk production averaged 5.14% for L-TMR. Supplementary lipids reduced (P < 0.002) milk fat concentration (g/100g) from 3.36 in C-TMR to 2.40 in L-TMR without effect (P = 0.43) on milk protein content (C-TMR = 3.20; L-TMR = 3.07 g/100g). Milk lactose (C-TMR = 4.86, L-TMR = 4.69 g/100g) and urea nitrogen contents (C-TMR = 21.18, L-TMR = 17.33 g/100g) tended (P < 0.056) to decrease in L-TMR as well as fat corrected milk output (C-TMR = 30.89, L-TMR = 29.49 kg/cow·day, P < 0.098). Lipid supplementation reduced (-23%) milk con-tent of C12:0 to C16:0 FA averaging 45.19 in C-TMR and 34.74 g/100g in L-TMR (P < 0.001). The atherogenic index (AI) of milk decreased (P < 0.001) from 2.69 in C-TMR to 1.50 in L-TMR (-44.2%). Concentration (g/100g) of elaidic (C18:1 trans-9) (0.23) and C18:1 trans-10 (0.44) FA increased (P < 0.001) in L-TMR milk. Milk vaccenic acid (trans-11 C18:1, VA) increased from 1.08 in C-TMR to 2.56 g/100g of FA in L-TMR (P < 0.001). Milk CLA content (cis-9, trans-11 C18:2) increased (127%) from 0.62 in C-TMR to 1.41 g/100g FA in L-TMR milk. Content of α-linolenic acid resulted 20% higher (P < 0.001) in L-TMR milk (0.35 g/100g FA) compared to C-TMR (0.30 g/100g FA). Milk DHA increased from 0 in C-TMR to 0.14 g/100g FA in L-TMR. The omega-6/-3 ratio in C-TMR milk (9.61) was reduced (P < 0.001) to 6.78 in L-TMR milk. Milk oleic acid (cis-9 C18:1) resulted higher (P < 0.001) in L-TMR (23.65) than in C-TMR (19.75 g/100g FA). The nutritional value of milk fat from confined cows was naturally improved by feeding polyunsaturated FA in the ration, obtaining a reduction of saturated FA and increased levels of healthy FA (CLA, DHA and α-linolenic).

Phenotypic variation of milk fatty acid composition of Pinzgauer cattle breed

This paper investigated sources of variation of milk fatty acid (FA, g/100 g total FA) profile routinely predicted by mid-infrared spectroscopy in Pinzgauer dual-purpose cattle breed. A total of 19,578 individual milk samples collected from 1232 cows and 77 herds between 2011 and 2014 were available for phenotypic characterisation. Data were analysed using a linear mixed model which included stage of lactation, parity and their interaction as fixed effects, and cow and herd-test-day as random effects. Milk yield averaged 20.87 kg/d, and means for fat, protein and casein were 4.01, 3.44 and 2.72%, respectively. Saturated FA (SFA), monounsaturated FA (MUFA) and polyunsaturated FA (PUFA) averaged 69.20, 25.43 and 3.19 g/100 g total FA, respectively. About half of the SFA were provided by C16:0 (31.24 g/100 g total FA), and almost all MUFA by C18:1 (22.18 g/100 g total FA). Fixed effects were significant in explaining the variation of the studied traits. Milk of first-parity cows had the lowest percentage of SFA, medium-chain FA and C14:0, and the greatest percentage of MUFA, PUFA, trans FA, short- and long-chain FA, and C18:1. Saturated FA, C14:0 and C16:0 increased from calving until 120 days in milk, whereas unsaturated FA, MUFA, PUFA, long-chain FA, C18:0 and C18:1 decreased. Although both parity and stage of lactation affected milk FA, greater variation was observed during lactation than among parities.

Diagnostic potential of the peptide-mediated magnetic separation (PMS)-phage assay and PMS-culture to detect Mycobacterium avium subsp. paratuberculosis in bovine milk samples.

Controlling the spread of Johne's disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), in domestic livestock is challenging. Current diagnostic methods lack sufficient sensitivity to detect subclinically infected animals, and thus, better diagnostic methods are needed. This study was carried out to investigate the diagnostic potential of two novel peptide-mediated magnetic separation (PMS)-based tests-a PMS-phage assay and PMS-culture-both of which have been developed and optimized to detect viable MAP cells in bovine milk. Individual milk samples (50ml) were obtained from 105 "non-infected" and 40 "MAP-infected" animals (classified as such on the basis of prior faecal culture and serum-ELISA results) in three dairy herds and tested in parallel by the PMS-phage assay and PMS-culture. Diagnostic sensitivity (DSe) and specificity (DSp) of the PMS-phage and PMS-culture methods were determined relative to the MAP infection status of the animal contributing the milk sample. The PMS-based tests applied individually showed moderate DSe (PMS-culture 0.250 and PMS-phage assay 0.325) and high DSp (0.962 and 1.000, respectively). When results of the two PMS-based tests were combined, DSe increased substantially to 0.525, and the DSp was calculated to be 0.962. It was concluded that combined application of the PMS-phage assay and PMS-culture provided the most complete picture regarding the presence of viable MAP in bovine milk samples. A comprehensive validation of the PMS-based assays relative to currently used diagnostic methods (faecal culture and serum-ELISA) would be the next step in assessment of the diagnostic potential of these novel PMS-based methods.

Field findings about milk ethanol stability: a first report of interrelationship between α-lactalbumin and lactose.

Milk ethanol stability is not only associated with microbiological acidification, but is a phenomenon with many variables that influence the balance of soluble salts, mainly calcium ion activity. On this basis, we wanted to find out more about milk ethanol stability by studying its relationship with milk protein fractions and others major components. The influence of milk composition on ethanol stability was assessed through a predictive model comprising 180 individual raw milk samples. An additional model was used to assess the ethanol stability status as a response to the proteins fractions quantified by electrophoresis. Of the total samples, 68% were classified as stable and 32% as unstable to alcohol. Milk ethanol instability increased at low values of lactose content and high values of ash percentage. α-Lactalbumin (α-La) was also associated with ethanol stability, and the higher the α-La percentage the lower were the chances of ethanol instability. The lower values of α-La in unstable milk samples might be related to lower content of lactose, as α-La promotes lactose synthesis, a key component for the osmotic balance of milk and thus its ethanol stability. This is the first field report linking ethanol stability indirectly with α-La. © 2017 Society of Chemical Industry.

Urinary metabolites of organophosphate esters: Concentrations and age trends in Australian children

There is growing concern around the use of organophosphate esters (OPEs) due to their suspected reproductive toxicity, carcinogenicity, and neurotoxicity. OPEs are used as flame retardants and plasticizers, and due to their extensive application in consumer products, are found globally in the indoor environment. Early life exposure to OPEs is an important risk factor for children's health, but poorly understood. To study age and sex trends of OPE exposures in infants and young children, we collected, pooled, and analysed urine samples from children aged 0–5years from Queensland, Australia for 9 parent OPEs and 11 metabolites. Individual urine samples (n=400) were stratified by age and sex, and combined into 20 pools. Three individual breast milk samples were also analysed to provide a preliminary estimate on the contribution of breast milk to the intake of OPEs. Bis(1-chloroisopropyl) phosphate (BCIPP), 1-hydroxy-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP), bis(1,3-dichloroisopropyl) phosphate (BDCIPP), dibutyl phosphate (DBP), diphenyl phosphate (DPHP), bis(2-butoxyethyl) phosphate (BBOEP), bis(2-butoxyethyl) 3-hydroxyl-2-butoxyethyl phosphate (3OH-TBOEP), and bis(2-butoxyethyl) hydroxyethyl phosphate (BBOEHEP) were detected in all urine samples, followed by bis(methylphenyl) phosphate (80%), and bis(2-ethylhexyl) phosphate (BEHP, 20%), and bis(2-chloroethyl) phosphate (BCEP, 15%). Concentrations of tris(2-chloroethyl) phosphate (TCEP), BCEP, tris(2-ethylhexyl) phosphate (TEHP), and DBP decreased with age, while bis(methylphenyl) phosphate (BMPP) increased with age. Significantly higher concentrations of DPHP (p=0.039), and significantly lower concentrations of TEHP (p=0.006) were found in female samples compared to males. The estimated daily intakes (EDIs) via breastfeeding, were 4.6, 26 and 76ng/kg/day for TCEP, TBP and TEHP, respectively, and were higher than that via air and dust, suggesting higher exposure through consumption of breast milk.

A longitudinal study of gastrointestinal parasites in English dairy farms. Practices and factors associated with first lactation heifer exposure to Ostertagia ostertagi on pasture

The gastrointestinal nematode Ostertagia ostertagi is an important cause of lost production, health, and welfare in cattle. Detailed records were obtained over a 5-yr period (2010-2015) by questionnaires and qualitative interviews to investigate the practices adopted by dairy farmers to control cattle helminth infections and the factors associated with heifer exposure to O. ostertagi on pasture. In total, 1,454 heifers' individual milk samples were collected over a 1-yr period (2014-2015) in 43 dairy farms in England and tested for O. ostertagi antibody by ELISA. Multilevel linear regression models were used to investigate the association between individual milk optical density ratio (ODR) against O. ostertagi and heifer management from birth to time of sampling. Farm and heifer median ODR against O. ostertagi were 0.98 (interquartile range = 0.76-1.02) and 0.64 (interquartile range = 0.42-0.84), respectively. The majority of heifers (88%) received an anthelmintic treatment before sampling in this study. After controlling for the effect of anthelmintic treatments, heifer individual milk ODR against O. ostertagi significantly increased with high stocking rate at first grazing and co-grazing with adult cows before calving. Conversely, heifer individual milk ODR against O. ostertagi significantly decreased when heifers had co-grazed with sheep and pasture grass had frequently been mowed. Overall, these results provide evidence to support targeting grazing management toward limiting the use of anthelmintics in dairy young stock to enable sustainable control of cattle helminth infections in England. However, to be accepted and adopted by farmers, these best practices would need to take into account farmers' perspectives and contextual challenges.

ALLERGENICITY ASSESSMENT OF GOAT'S MILK DIFFERENT EXPRESSIONS OF ALPHA S1-CASEIN IN PATIENTS ALLERGIC TO COW'S MILK

Background: Cow’s milk protein allergy (CMPA) is the most common food allergy, especially, in infants and young children. In this case, milk from other mammalian species has been suggested as a possible nutritional alternative to cow’s milk. Goat’s milk is used quite popular to replace for cow’s milk. In the goat species, αS1casein (αS1-CN), coded by the CSN1S1 gene, is characterized by qualitative and quantitative polymorphisms extensively. This aim of this study is to evaluate allergenicity of goat’s milk containing differentk kinds of αS1CN. Methods: Individual milk samples from 26 selected goats with different CSN1S1 genotypes were analyzed by SDS-PAGE and immunoblotting by using sera from children allergic to cow’s milk with IgE specific to CN and/or serum protein. Results: The absence of reactivity for the αs1-CN highlighted with immunoblotting for all goat milk samples. Conclusions: The goat’s milk with particular genotype for CSN1S1 could be used as a source protein alternative in the case of αs1-CN awareness. Furthermore, these tests could be useful for evaluating from time to time the reactivity of patients with CMPA against milk proteins of these goats selected to establish the safety of its use in the specific subject. Key words: Allergenicity, milk protein, goat, alphaS1-Casein, CSN1S1gene

Coagulase gene polymorphism, enterotoxigenecity, biofilm production, and antibiotic resistance in Staphylococcus aureus isolated from bovine raw milk in North West India

BackgroundStaphylococcus aureus is the predominant bacterium responsible for various diseases in animals and humans. Preventive strategies could be better implemented by understanding the prevalence, genetic patterns, and the presence of enterotoxin and biofilm-producing genes along with the antibiotic susceptibility of this organism. This study was conducted in Rajasthan, the northwestern state of India, holding the largest population of cattle that makes it the second largest milk producer in India and no such prior information is available on these aspects.MethodsA total of 368 individual quarter bovine raw milk samples were collected from 13 districts of Rajasthan, and screened for the presence of S. aureus. Microbiological and molecular approaches were followed for bacterial identification. Genetic diversity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) of coagulase gene (coa), whereas enterotoxin and biofilm-producing genes were studied by PCR analysis. Antibiotic strips were employed to study the antibiotic resistance among strains.ResultsIn all, 73 S. aureus strains were obtained from 368 bovine raw milk samples out of that only 30 showed the presence of coa. Nine types of coa patterns ranging from 730 to 1130 bp were observed among these isolates. PCR–RFLP of coa distinguished the isolates into 15 genotypic patterns, of which patterns I, IV, V, and VI were predominant. Of the isolates, 30% were positive for sec, 10% for sea, and 3.3% for seb; these genes are responsible for enterotoxin production, whereas all isolates were found positive for icaAD and eno. The prevalence rates of other biofilm-producing genes fnbA, clfB, ebpS, sasG, fnbB, sasC, cna, bap, fib and, bbp were 97, 93, 90, 80, 80, 77, 53, 27, 10, and 6.6%, respectively. Twenty-seven (90%) strains were multidrug resistant, of which 15 were methicillin resistant. Maximum sensitivity was reported for kanamycin and it could be considered as a drug of choice for controlling S. aureus mediated cattle infections in the studied regions.ConclusionsOverall, these strains could cause several diseases to humans, insisting the need for developing a stricter hygiene program for improving milking practices and animal health.

Polybrominated diphenyl ethers and indicator polychlorinated biphenyls in human milk from China under the Stockholm Convention

Seven congeners of polybrominated diphenyl ethers (PBDEs) (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153,BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) (PCB-28, PCB-52, PCB-101, PCB-138, PCB-153 and PCB-180) were measured in 32 regional pooled human milk samples originating from 1760 volunteering primiparous mothers to evaluate the current human body burden of general population and the temporal trend in China. Individual human milk samples were collected following a WHO-designed procedure. This work is one of parts of the evaluation of effectiveness of Stockholm Convention performance. The concentration of ∑7PBDEs ranged from 0.3 ng g−1 lipid to 4.0 ng g−1 lipid with a mean of 1.5 ng g−1 lipid. The concentration of ∑6PCBs ranged from 2.3 ng g−1 lipid to 19.0 ng g−1 lipid with a mean of 6.6 ng g−1 lipid. By comparing with background determination in 2007, there was no significance for ∑7PBDEs. However, BDE-47, BDE-99, and BDE-100 significantly decreased with an average of 45%, 48%, and 46%, respectively, from 2007 to 2011, and an increase of BDE-183 was founded in most regions. For ∑6PCBs, there was a significant decline with an average reduction of 41% from 2007 to 2011. These results indicate the effectiveness of reduction and elimination of POPs in China. Future national human milk biomonitoring is worthy to be done to further evaluate the time trend and effectiveness of the Convention performance.

Analyse of Relationships Between Some Milk Indicators of Cow Energy Metabolism and Ketosis State

Good health is important for animal reproduction and support of foodstuff chain quality and safety. Milk is suitable for noninvasive monitoring. Analyses of milk composition and result interpretation along environmental conditions and physiological principles plays important role in health control. Ketosis is a disorder of energy metabolism in dairy cows. It deteriorates milk yield (MY) and quality and animal reproduction and can have a fatal impact. Aim was to analyse relationships between milk energy metabolism indicators as acetone (AC) and component quotients which can serve in health control and estimate their thresholds. AC and fat/lactose (F/L) and fat/crude protein (F/CP) ratio could represent good ketosis indicators. There were 960 individual milk samples from the Holstein (H) and Czech Fleckvieh (CF) dairy cows (1:1). Their whole lactations, first third of lactations (FTL) and summer and winter seasons were analysed. Lactation MY of included herds (7) varied from 5,500 to 10,000 kg. Milk AC levels did not differ (P &gt; 0.05) between H and CF breed in whole lactation but differed in FTL (H 3.88 and CF 2.72 mg.l–1; P &lt; 0.05). This difference 1.16 mg.l–1is equal to 29.9 % and this is not too much essential. The F/L ratio was not affected (P &gt; 0.05) by parity and season in whole lactation but was influenced (P &lt; 0.01 and &lt; 0.05) in this way during FTL. As maximum there can be explained only 17.8 % of variability (correlation index 0.42; P &lt; 0.001) in log AC values by F/L quotient variability for CF in FTL in summer season. As maximum there can be explained up to 84.4 % of variations (correlation index 0.92; P &lt; 0.001) in F/CP values by F/L quotient variations for H in FTL in summer season. Equations were used for model calculation of AC and F/L cut‑off limits to subclinical ketosis indication in FTL period. These were from 2.05 to 3.29 mg.l–1about AC and from 0.84 to 0.87 about F/L according to breeds (CF and H) and lactation parity (1stand others). The results can be used in methods of cow health problem identification, prevention, treatment and troubleshooting during lactation.

Somatic Cell Count and Milk Yield Losses in Goats

This work is aimed at prediction and quantification of goat milk yield (MY, kg) losses by the somatic cell count (SCC, 103.ml−1) in milk recording. The goal is to support the prevention of milk secretion disorders, milk yield and quality. During two years there were evaluated composition and properties of individual milk samples (n = 1 173). There were included animals of brown short‑haired (BSH) breed and BSH × white short‑haired in one flock. The linear and nonlinear regression, interpolation, extrapolation, approximation and qualified estimation were used for milk losses prediction along the SCC. The relevant values of the SCC arithmetic and geometric mean and median and MY arithmetic mean were: 1,400 103.ml−1 (with high variability of 128 %), 745 and 747 103.ml−1; 2.94 kg/ day. The relationship between fat and crude protein had a correlation coefficient of 0.395, P &lt; 0.001. There were stated the correlations between SCC and: lactose −0.416, P &lt; 0.001; solids non fat −0.25, P &lt; 0.001; MY −0.135, P &lt; 0.01. The relationship between SCC and MY was negative along months, 6 cases out of 7 and significant in March and May (P &lt; 0.05 and P &lt; 0.01). For instance predicted MY for SCC intervals 1–1.999, 2–2.999, 3–3.999, 4–4.999, 5–5.999, 6–6.999 and ≥ 7 thousands 103.ml−1 may be 3.99, 3.77, 3.6 , 3.46, 3.33, 3.23 and 3.13 kg in 3rd month etc. The corresponding MY losses by SCC are evident from this trend. The result use is focused on the original dairy goat farm and use elsewhere is possible in farms with similar SCC, goat milk yield and rearing system.