Variations in mammary glucose uptake were measured during the normal pregnancy-lactation cycle in dairy goats. In addition mammary glucose uptake was studied in response to somatotropin (ST) treatment in mid-lactation and acute increases in glucose concentration induced by sodium-propionate challenge in early lactation. Mammary glucose uptake was independent of arterial glucose, insulin and Insulin-like Growth Factor-1 (IGF-1) concentrations during lactation and during acute increases in arterial glucose concentration. Glucose uptake in the lactating mammary gland of the goat must therefore be carried out by an insulin-independent carrier, possible GLUT1, and glucose supply is not a limiting factor for uptake under in vivo conditions. Extraction of glucose uptake changed markedly during the normal course of lactation, following the overall changes in milk yield. Concentrations of glucose in skimmed milk, believed to reflect intracellular glucose concentration, changed in opposite directions, resulting in decreasing ratios of arterialratioskimmed milk glucose concentration with progressing lactation. Thus, mammary synthetic capacity also involves a capacity for glucose uptake, which may be influenced by variations in glucose carrier numbers, as well as mammary metabolic activity (intracellular glucose concentration). In contrast to the situation during the normal course of lactation, ST stimulated milk yield, despite less efficient glucose extraction.

1. The denaturation of albumin and globulin took place rapidly in samples of milk heated at temperatures of 75°C. and above, and was complete in approximately 60, 30, 10–15, and 5–10 min. at 80, 90, 95, and 100°C. respectively.

2. There was no change in the non-protein nitrogen content of milk on heating at temperatures up to 100°C.; on continued heating at 95 and 100°C. extremely small amounts of proteose were produced by hydrolysis of protein.

3. In milk heated at 115 and 120°C. the denaturation of albumin and globulin was followed by appreciable hydrolysis of protein, which resulted in considerable increases in the proteose and in the non-protein nitrogen contents.

The present study investigates the effect of adaptive resistance to ciprofloxacin (Cip) and benzalkonium chloride (BC) on biofilm formation potential (BFP), efflux pump activity (EPA) and haemolysin activity of Escherichia coli isolates of dairy origin. All the isolates, irrespective of antimicrobial susceptibility, developed significant adaptive resistance (P < 0·05). All the resistant phenotypes (antibiotic resistant: AR; & biocide resistant: BR) were stronger biofilm former and post-adaptation, an insignificant change was observed in their BFP. Whereas, post-adaptation, non-resistant isolates (antibiotic non-resistant: ANR; biocide non-resistant: BNR) transformed from poor or moderate to strong biofilm formers. Post-adaptive percentage increase in EPA was highly significant in non-resistant categories (P < 0·01) and significant at P < 0·05 in BR category. Interestingly, post-adaptive increase in EPA in BR isolates was more than that in AR yet, the latter exhibited greater adaptive resistance than the former. These findings indicated prevalence of some other specific resistance mechanism/s responsible for adaptive resistance against Cip. Strain specific variations were observed for stability of adaptive resistance and haemolysin activity for all the categories. Our findings especially in reference to post-adaptation upgradation of BFP status of non-resistant isolates seems to be providing an insight into the process of conversion of non-resistant isolate into resistant ones with enhanced BFP. These observations emphasize the serious implications of sub-lethal residual levels of antimicrobials in food environments and suggest a role of food chain in emergence of antimicrobial resistances.

The concentrations of seven types of microorganism in the milk produced by farms using high quality milking procedures were monitored monthly. The most commonly encountered bacterium was Pseudomonas, whose concentration varied greatly between samples, but lactococci, lactobacilli and yeasts were also present at more stable concentrations. Staphylococcus aureus and β-glucuronidase-positive Escherichia coli were occasionally detected. Listeria monocytogenes was found in the samples from only one farm, while Yersinia enterocolitica was never detected. There were seasonal variations in the concentrations of lactobacilli and yeasts over the 2 years monitored. The changes in certain bacteria (Lactococcus, Lactobacillus) on any given farm were very similar from one year to the next. The microbiological characteristics of the milk from the farms examined seemed to be fairly constant. The profiles of some bacteria used for cheesemaking were relatively stable over time. It thus seems that the milk provided by different producers could be typed.

The study investigated the seasonal changes in the compositional, physicochemical and processing characteristics of milk from a mixed-herd of spring- and autumn-calving cows during the year 2014–2015. The volume proportion of autumn-calving milk (% of total milk) varied with season, from ~10–20 in Spring (March–May), 5–13 in Summer (June–August), 20–40 in Autumn (September–November) and 50–100 in Winter (December–February). While all characteristics varied somewhat from month to month, variation was inconsistent, showing no significant trend with progression of time (year). Consequently, season did not significantly affect many parameters including concentrations of total protein, casein, whey protein, NPN, total calcium, pH, rennet gelation properties or heat stability characteristics. However, season had a significant effect on the concentrations of total P and serum P, levels of αs1- and β-caseins as proportions of total casein, casein micelle size, zeta potential and ethanol stability. The absence of a significant effect of season for most compositional parameters, rennet gelation and heat-stability characteristics suggest that milk from a mixed-herd of spring- and autumn-calving cows is suitable for the manufacture of cheese and milk powder on a year-round basis, when the volume proportion of autumn milk, as a % of total, is similar to that of the current study.

The aim of this review was to present various topics related to lactose intolerance with special attention given to the role of fermented foods and probiotics in alleviating gastrointestinal symptoms. Lactose intolerance is a common digestive problem in which the human body is unable to digest lactose, known as milk sugar. Lactose intolerance can either be hereditary or a consequence of intestinal diseases. Recent work has demonstrated that fermented dairy products and probiotics can modify the metabolic activities of colonic microbiota and may alleviate the symptoms of lactose intolerance. We suggest that, lactose free dairy products could be recommended as alternatives for the alleviation of lactose intolerance and for the promotion of human health and wellness.

The overall objective of this study was to investigate how relevant research publications address the validity of diagnostic methods for acute puerperal metritis (APM) in dairy cows, a disease commonly treated with antibiotic drugs. Therefore, a literature search was conducted in Journal of Dairy Science, Theriogenology, Animal Reproduction Science and The Veterinary Journal utilizing the ScienceDirect database. The search revealed 259 articles addressing APM. After applying exclusion criteria, a total of 48 trials remained. It was determined whether the author gave a clear definition of APM, the time of diagnosis relative to calving, and the person who performed the diagnosis. Studies were checked for the presence of definitions of possible findings, thresholds, and test characteristics of the methods used. Overall 9 different diagnostic methods were employed. On average 2·5 ± 1·75 diagnostic methods were used in a study. References to support the use of the diagnostic methods were provided in 10 of 48 articles (20·8%). Vaginal discharge, transrectal palpation and rectal temperature were examined in 39, 22, and 21 of the studies, respectively. Thresholds for diagnostic tests and test characteristics were mentioned in 6 and 3 of the 48 articles, respectively. Based on this systematic review of 48 research papers the evidence supporting the use of the diagnostic methods to identify cows with APM has either been not reported or is weak. In conclusion, the reporting of the diagnostic methods to identify cows with APM needs to be improved and further high-quality research is necessary to improve diagnostic performance of the methods employed.

La formation de gaz dans la pâte du fromage fondu, au cours de la conservation, représente un défaut assez fréquent qui entraîne le gonflement ou même l'éclatement des emballages, notamment lorsque ces derniers sont constitués par des boites métalliques.

Small numbers of bovine staphylococci, usually less than 30, were infused into the teat cistern of 17 cows secreting less than 100 000 leucocytes/ml milk. Infection was assumed to have occurred if the organisms multiplied sufficiently to be recovered in the foremilk and inflammation was regarded as demonstrated if there was an increase in leucocytes. If the staphylococci were recovered at the 1st post-infusion milking they were consistently recovered thereafter and inflammation always followed but was never evident at the 1st post-infusion milking. Inflammation was usually evident by the 3rd but in one instance was delayed to the 11th post-infusion milking. There was never inflammation in the absence of infection. When there was a high probability that the infusion contained one organism or more, infection occurred in 2 of 10 quarters infused with coagulase-negative staphylococci and 23 of 25 quarters infused with coagulase-positive staphylococci.

A significant positive relationship was found between the number of staphylococci found at the 1st post-infusion milking and the number of leucocytes at the 3rd postinfusion milking.

Reliable identification of the aetiological agent is crucial in mastitis diagnostics. Real-time PCR is a fast, automated tool for detecting the most common udder pathogens directly from milk. In this study aseptically taken quarter milk samples were analysed with a real-time PCR assay (Thermo Scientific PathoProof Mastitis Complete-12 Kit, Thermo Fisher Scientific Ltd.) and by semi-quantitative, in-depth bacteriological culture (BC). The aim of the study was to evaluate the diagnostic performance of the real-time PCR assay in routine use. A total of 294 quarter milk samples from routine mastitis cases were cultured in the national reference laboratory of Finland and examined with real-time PCR. With BC, 251 out of 294 (85·7%) of the milk samples had at least one colony on the plate and 38 samples were considered contaminated. In the PCR mastitis assay, DNA of target species was amplified in 244 samples out of 294 (83·0%). The most common bacterial species detected in the samples, irrespective of the diagnostic method, was the coagulase negative staphylococci (CNS) group (later referred as Staphylococcus spp.) followed by Staphylococcus aureus. Sensitivity (Se) and specificity (Sp) for the PCR assay to provide a positive Staph. aureus result was 97·0 and 95·8% compared with BC. For Staphylococcus spp., the corresponding figures were 86·7 and 75·4%. Our results imply that PCR performed well as a diagnostic tool to detect Staph. aureus but may be too nonspecific for Staphylococcus spp. in routine use with the current cut-off Ct value (37·0). Using PCR as the only microbiological method for mastitis diagnostics, clinical relevance of the results should be carefully considered before further decisions, for instance antimicrobial treatment, especially when minor pathogens with low amount of DNA have been detected. Introducing the concept of contaminated samples should also be considered.

High temperature is a major stress that negatively affects welfare, health, and productivity of dairy animals. Heat-stressed animals are more prone to disease, suggesting that their immunity is hindered. Although productive and physiologic responses of dairy animals to heat stress are well known, there is still limited information on the response at the transcriptome level. Our objective was to evaluate the changes in performance and blood transcriptomics of dairy goats under heat stress. Eight multiparous Murciano-Granadina dairy goats in mid-lactation were assigned to 1 of 2 climatic treatments for 35 d. Treatments and temperature-humidity index (THI) were: (1) thermal neutral (TN: n = 4; 15–20 °C, 40–45%, THI = 59–65), and (2) heat stress (HS: n = 4; 12 h at 37 °C–40%, THI = 86; 12 h at 30 °C–40%, THI = 77). Rectal temperature, respiratory rate, feed intake and milk yield were recorded daily. Additionally, milk composition was evaluated weekly. Blood samples were collected at d 35 and RNA was extracted for microarray analyses (Affymetrix GeneChip Bovine Genome Array). Differences in rectal temperature and respiratory rate between HS and TN goats were maximal during the first 3 d of the experiment, reduced thereafter, but remained significant throughout the 35-d experimental period. Heat stress reduced feed intake, milk yield, milk protein and milk fat contents by 29, 8, 12, and 13%, respectively. Microarray analysis of blood revealed that 55 genes were up-regulated, whereas 88 were down-regulated by HS. Bioinformatics analysis using the Dynamic Impact Approach revealed that 31 biological pathways were impacted by HS. Pathways associated with leukocyte transendothelial migration, cell adhesion, hematopoietic cell lineage, calcium signaling, and PPAR signaling were negatively impacted by HS, whereas nucleotide metabolism was activated. In conclusion, heat stress not only negatively affected milk production in dairy goats, but also resulted in alterations in the functionality of immune cells, which would make the immune system of heat-stressed goats less capable of fending-off diseases.

A cover for a 40 gal. cheese vat has been specially designed to allow cheese to be made under conditions which prevent the entry of micro-organisms into the vat from the dairy environment. The technique employed is described. Using milk free from lactobacilli it has been possible to make Cheddar cheese in which no lactobacilli grew during the ripening period. An assessment of the role of these and other micro-organisms in cheese ripening should now be possible.

The technique should also be of help in other cheese investigations where control of the microflora is desired.

Folic acid activity was determined for National Dried Milk and for 5 proprietary dried milk foods for babies, for a proprietary liquid milk baby food and for 8 brands of tinned evaporated milk. For comparison, values were determined for mature breast milk, for raw bulk cow's milk, for bottled pasteurized cow's milk and for goat's milk.

Human milk and raw and pasteurized cow's milk all had much the same folate activity, equivalent to about 54 µg folic acid/1. Values for goat's milk were much lower, around 6 µg/1.

Values for the reconstituted baby milks ranged from 9 to 65 µg/1, though only 2 of the products had markedly lower values than breast milk. The question is discussed whether the folic acid requirement in infants can be met by formulas based on cow's milk without having recourse to folic acid supplementation.

Small volumes of milk each containing an average of less than 10 colonyforming units of Staphylococcus aureus were injected into the teat cisterns of 39 quarters of 10 cows.

Typical staphylococci were recovered from only 14 quarters following overnight incubation of milk stripped manually from each quarter 10 min after injection. There was an inverse relationship between the total leucocyte count of the milk taken from the quarter before infusion and recovery of staphylococci.

From 4 of 8 quarters from which Staph. aureus could not be recovered by enrichment it was possible to recover the organism by centrifuging the milk and culturing the deposit of leucocytes and bacteria.

It is suggested that release of ingested staphylococci from defunct phagocytes may be important in initiation of infection, failure of antibiotic therapy and recurrence of infection.

Unsupplemented acid goat whey containing 0·96% protein and 2·76% lactose was fermented aerobically with 32 microflora extracted from various raw milk cheeses and dairy products. These microflora were screened for their ability to hydrolyse whey proteins (α-lactalbumin and/or β-lactoglobulin) and to generate peptides inhibitors of Angiotensin I Converting Enzyme. Five microflora were able to degrade whey protein. The most efficient microflora was able to fully hydrolyse α-lactalbumin and to a lesser extend β-lactoglobulin. It was extracted from Bamalou des Pyrenées cheese. Micro-organisms involved consisted of yeast Kluyveromyces marxianus and lactobacillus Lactobacillus rhamnosus. Both were able to produce ACE inhibitory peptides after whey fermentation.

Interesterification of milk fats resulted in increased softening points, hardness and high melting glycerides (HMG). Increasing the content of trans-unsaturated acyl groups in milk fat resulted in increased softening points and hardness. While the increased solid fat content after interesterification occurred mostly at the higher measuring temperatures, the increase due to isomerization occurred mainly at the lower measuring temperatures. However, in both cases hardness was increased at all measuring temperatures. These results indicate that glyceride structure and trans-unsaturated acyl content influence the physical properties of the solidified fat.

Samples of bulk silo milk from 5 creameries in the south west of Scotland were taken over a 16-month period. The average radii of casein micelles were determined by measuring the wavelength dependence of the turbidity of skim-milk diluted with its own ultrafiltrate. In addition, the concentrations of casein, soluble and colloidal Ca and P1 were measured. The average size of casein micelles followed a pronounced seasonal trend with smaller average sizes in the summer compared to the winter period, confirming earlier observations made on milks from individual cows. The average size of casein micelles correlated positively (r = +0·777, P < 0·001) with the amount of colloidal P1 per unit weight of casein and negatively (r = −0·77, P < 0·001) with casein-bound Ca. Average micelle radius was negatively correlated with heat stability at the natural pH of milk (r = −0·61, P < 0·001), but there did not appear to be any causal relation between these 2 variables.

The concentrations of lactose, potassium, sodium, chloride and citric acid were determined in milks of cows, sows, ewes and goats. For cows, sows and ewes trends with lactation are reported and for all species correlations between constituents in milks secreted in mid-lactation are given. The results are discussed in relation to the secretion of water-soluble constituents in milk.

Eleven Shorthorn cows were milked for 14 days before their expected calving date. The total amount of prepartum secretion varied, between cows, from 1 to 961.

Determinations of total solids, fat, solids-not-fat, lactose, total protein, ash, calcium, phosphorus, chloride, casein, albumin, globulin, proteose-peptone, N.P.N., vitamin A and carotenoids were made regularly on the secretions of eight of these cows during the prepartum period, and for 4 days postpartum; and, for comparison, on five samples of Short-horn colostrum each representing the total secretion obtained from the two milkings within the first 24 hr. after calving.