Three sources of sensory data: cow's individual rumination duration, activity and milk yield were evaluated as possible indicators for clinical diagnosis, focusing on post-calving health problems such as ketosis and metritis. Data were collected from a computerised dairy-management system on a commercial dairy farm with Israeli Holstein cows. In the analysis, 300 healthy and 403 sick multiparous cows were studied during the first 3 weeks after calving. A mixed model with repeated measurements was used to compare healthy cows with sick cows. In the period from 5 d before diagnosis and treatment to 2 d after it, rumination duration and activity were lower in the sick cows compared to healthy cows. The milk yield of sick cows was lower than that of the healthy cows during a period lasting from 5 d before until 5 d after the day of diagnosis and treatment. Differences in the milk yield of sick cows compared with healthy cows became greater from 5 to 1 d before diagnosis and treatment. The greatest significant differences occurred 3 d before diagnosis for rumination duration and 1 d before diagnosis for activity and milk yield. These results indicate that a model can be developed to automatically detect post-calving health problems including ketosis and metritis, based on rumination duration, activity and milk yield.

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 effect of temperature and time of heating whole milk on the renninclotting time, the primary phase of rennin action and the protein (mainly β-lactoglobulin) soluble in 2% trichloroacetic acid (TCA), have been studied. Considerable changes in these parameters occurred above 60°C. The primary phase was inhibited (the degree of inhibition being both temperature and time-dependent), the clotting time was increased, and the protein soluble in 2% TCA decreased considerably.

It is suggested that the inhibition of the primary phase was due to complex formation between κ-casein and β-lactoglobulin, the increase in clotting time to a combination of complex formation and a change in the distribution of Ca, and the decrease in β-lactoglobulin to both its interaction with κ-casein and its heat denaturation. The relevance of such changes to the heat stability of milk is discussed.

The amounts of total lipid and fatty acids consumed, leaving the stomach and excreted in the faeces were examined in 4 sheep fitted with rumen and re-entrant duodenal cannulas. Diets of high (HM1) and low (CM1) roughage content were given at 0·9 times maintenance and the low-roughage diet was also given at 1·7 and 2·3 times maintenance. With all the rations more fatty acid left the abomasum than was consumed in the food, the difference being greater on ration CM1 than on ration HM1 and increasing irregularly with the amount of the low-roughage ration fed. Of the fatty acid entering the duodenum in the chyme, 72–89% was digested in the intestine. About 80% of the increase in fatty acids in the stomach was stearic acid and most of the remainder was palmitic acid. Almost all the polyunsaturated C18 acids ingested in the food were hydrogenated in the stomach, and the amounts of oleic acid were also greatly reduced, although more oleic acid entered the duodenum in the chyme with ration CM1 than with ration HM1. The possible origins of the increase in fatty acids in the stomach are discussed.

The ability of total milk proteose peptone and individual proteose peptone components to inhibit lipolysis in milk was examined. Proteose peptone (1·5 mg/ml) when added to milk inhibited lipolysis, and component 3 was a more effective inhibitor than component 5 or component 8-fast. Inhibition by proteose peptone also occurred when the milk was treated with between 2 and 20% v/v bovine blood serum or with 5 μg/ml heparin. In vitro activity of milk lipoprotein lipase and its stability were not affected by proteose peptone. It was concluded that proteose peptone does not interact with lipase or its activator and that the mechanism of inhibition involves the substrate.

The experiment used 45 Comisana ewes, divided into 3 groups of 15. The aim was to determine the effects of two different stocking densities and two different housing conditions on welfare, and on production performance of dairy ewes. The stocking densities tested were: high stocking density (1·5 m2/ewe, HD group) and low stocking density (3 m2/ewe, LD group); the two housing conditions tested were: ewes housed indoors (LD group, 3 m2/ewe) and ewes allowed to use an outdoor area (LDP group, 3 m2/ewe divided into 1·5 m2/ewe indoors and 1·5 m2/ewe outdoors). At the beginning of the experiment, and then every 2 months, the cell-mediated immune status of sheep was evaluated. One month after the beginning of the experiment, and 20 d later, the ewes were injected with chicken egg albumin (OVA) to assess their humoural immune responses. Starting from the beginning of the experiment and then monthly, behavioural activities of ewes were monitored using 15-min scans. After lamb weaning, milk yield from individual ewes was measured and milk composition analysed weekly. Housing conditions (low density reared ewes indoors v. low density reared ewes with free access to an outdoor area) affected cell-mediated response, which was higher in LDP than in LD ewes. Concentrations of anti-OVA IgG were mainly influenced by space allowance, with higher antibody titres in LD than in HD ewes throughout the experiment. Both housing conditions and space allowance affected sheep behavioural activities: a greater proportion of LDP ewes displayed standing and drinking behaviours than LD ewes, and a greater proportion of LD ewes was observed walking than HD ewes. Ewes allowed access to the outdoor area had a higher protein content and lower somatic cell count in their milk, whereas reduced space allowance led to a reduction in milk yield and an increase in somatic cell count of milk. Results indicate that both increased space allowance and availability of outdoor area can improve the welfare and production performance of the lactating ewe.

The effects of the isocaloric replacement of starch in a low-fat concentrate mixture by either 5 or 10% ‘stearic acid’ (85% pure) or 10% ‘palmitic acid’ (85% pure) on the yield and composition of milk fat were investigated in a feeding experiment with 12 cows in mid-lactation. The concentrate mixtures were given with a highroughage diet that supplied daily 4·4kg of hay and 2·7kg of sugar-beet pulp.

The inclusion of 5 or 10% ‘stearic acid’ in the concentrate mixture decreased the concentrations and yields of 10:0, 12:0, 14:0, 14:1, 16:0 and 16:1 in the milk fat but increased the concentrations and yields of 18:0 and 18:1. When the concentrate mixture contained 10% ‘stearic acid’ the decreases in the yields of the shorter chain acids and the increases in the yields of 18:0 and 18:1 in the milk fat were more pronounced than when the concentrate mixture contained 5% ‘stearic acid’. The inclusion of 10% ‘stearic acid’ in the concentrate mixture also decreased the concentrations of 6:0 and 18:2 in the milk fat. The inclusion of 10% ‘palmitic acid’ in the concentrate mixture decreased the concentrations of 6:0, 8:0, 10:0, 12:0, 14:0, 14:1, 18:0 and 18:2 in the milk fat but increased the concentrations of 16:0 and 16:1. This dietary treatment also reduced the yields of 6:0, 10:0, 12:0, 14:0 and 18:2 but increased the yields of 4:0, 16:0 and 16:1 in the milk fat. The inclusion of 5% ‘stearic acid’ or 10% ‘palmitic acid’ in the concentrate mixture increased the yield of total milk fat.

The inclusion of 10% ‘palmitic acid’ or 10% ‘stearic acid’ in the concentrate mixture increased the relative proportions of propionic and iso-butyric acids in the rumen liquor but decreased the proportions of η-butyric and valeric acids. The inclusion of ‘stearic acid’ at the level of 5% in the concentrate mixture increased the relative proportions of iso-butyric and iso-valeric acids but decreased the proportion of butyric acid in the rumen liquor.

Of 161 cultures of aerobic sporeformers isolated from raw and pasteurized milk 96 were found to be B. cereus, 27 B. mycoides, 17 B. subtilis, 11 B. sphaericus, 3 B. megatherium, 2 B. pumilus, 1 B. firmus and 4 were unidentified strains.

Typical broken cream followed by rapid sweet curdling of sterile milk was produced by 36 of 39 strains of B. cereus and 5 strains of B. mycoides examined. Three strains of B. cereus failed to produce broken cream. These 3 strains were atypical in that they failed to produce lecithinase, unlike the remaining 93 strains isolated during this study. Other species of aerobic sporing bacilli tested, including 17 strains of B. subtilis, 10 of B. sphaericus, 2 of B. megatherium, 2 of B. pumilus and 1 of B. firmus, all failed to produce broken cream and in fact produced no visual change in milk within 48 hr. at 22° C.

Under the conditions of our experiments, 48 out of 60 samples of fresh farm milk and 12 out of 14 samples of freshly bottled pasteurized milk developed broken cream within 18 hr. at 22° C. followed by sweet curdling within a further 24 hr. Strains of B. cereus or B. mycoides were isolated from all samples showing broken cream, but only 3 atypical strains of B. cereus were isolated from the 14 samples which did not develop the fault.

It seems that the production of broken cream is in some way associated with the production of lecithinase by B. cereus and B. mycoides. This view is supported by the fact that three non-lecithinase producing strains of B. cereus were also unable to produce broken cream. However, attempts to reproduce the fault by adding a concentrated culture filtrate to sterile milk or cream were unsuccessful.

Because of the widespread distribution of spores of B. cereus and B. mycoides in both raw and pasteurized milk, the absolute prevention of broken cream does not seem possible, but preliminary observations suggest that maintenance of milk at 5° C. or lower from the time of pasteurization until delivery to the consumer may sufficiently delay the onset of the fault to obviate the difficulty in practice except in very hot weather in households where insufficient care is taken to keep milk cool.

Use of a model of the renneting reaction has led to the definition of the amounts of soluble casein present in milks of different concentrations, at the time of clotting. It is shown that, although the clotting time (RCT) is relatively little affected by the concentration of milk by ultrafiltration, the proportion of casein which is soluble at the RCT is highly dependent upon the concentrations of both milk and rennet. This may affect the structure of the curd.

Milk from cows fed a low-fat diet high in cereals designed to stimulate fat synthesis de novo was lower in unsaturated fatty acids (21·3%) than milk from cows fed a diet high in fat, mainly from roasted soy beans (41·3% unsaturated fatty acids). Buttermilk from the more unsaturated milk was less oxidatively stable during storage (at 4 °C, followed for 11 d) than buttermilk from the more saturated milk, as monitored both by primary lipid oxidation products (lipid hydroperoxides) and by the secondary lipid oxidation product, hexanal. Fat-soluble antioxidants, β-carotene and α-tocopherol, analysed by HPLC, were not consumed during storage for either of the two types of buttermilk. In contrast, the antioxidative capacity of the serum phase decreased during storage as evaluated in a radical scavenging assay based on the semi-stable water-soluble radical nitrosodisulphonate (Fremy's salt). The time course for the decrease in water-soluble antioxidants was very similar for the two types of buttermilk suggesting that oxidation is initiated in the serum phase independently of fatty acid composition.

In this study, the physicochemical properties of a low-fat dried yogurt paste (kashk) were determined, and the effects of different concentrations (0, 0·1, 0·3 and 0·5% w/w) of gum tragacanth exudates from Astragalus gossypinus on the stability and texture of the samples were investigated by measuring amount of syneresis, turbidity, particle size distribution (PSD), flow behaviour and viscoelastic properties. The flow behaviour index was not very sensitive to the concentration of gum, while a remarkable concentration dependency of the power-law consistency coefficient and Herschel–Bulkley yield stress was observed. The initial increase in the gum concentration at 0·1 and 0·3% levels led to a higher degree of syneresis, which was related to the depletion flocculation mechanism. However, the reduced amount of syneresis in samples containing 0·5% gum tragacanth was attributed to the significant increase in viscosity of the continuous phase, which is also accompanied by trapping of the aggregated casein particles. The presence of 3% salt in the samples may have led to the neutralization of charges on the surface of gum tragacanth; consequently, the non-adsorbing behaviour of high-ionic-strength polysaccharides inhibited the formation of electrostatic protein–polysaccharide complexes. Furthermore, maximum values of polydispersity, syneresis and tan δ at high frequencies were found in samples containing 0·1% gum tragacanth.

The effect of brining time and smoking on the free fatty acid content of Idiazabal cheese during ripening was examined. The main free fatty acids considered underwent at least some increase during the first stage of ripening before day 90 and tended to level off around a constant value towards the end of the ripening period. There were significant differences in free fatty acid levels during ripening among cheeses with different brining times and between smoked and unsmoked cheeses. Brining time and smoking exerted marked effects on lipolytic activity during cheese ripening, depending upon the free fatty acid involved and ripening time. In general, brining and smoking led to increases in free fatty acid levels at the end of the ripening period; the different behaviour of butyric acid may be due to a specific lipolytic activity.

ATP-binding cassette (ABC) transporters play a pivotal role in human physiology, and mutations in these genes often result in severe hereditary diseases. ABC transporters are expressed in the bovine mammary gland but their physiological role in this organ remains elusive. Based on findings in the context of human disorders we speculated that candidate ABC transporters are implicated in lipid and cholesterol transport in the mammary gland. Therefore we investigated the expression pattern of selected genes that are associated with sterol transport in lactating and nonlactating mammary glands of dairy cows. mRNA levels from mammary gland biopsies taken during lactation and in the first and second week of the dry period were analysed using quantitative PCR. Five ABC transporter genes, namely ABCA1, ABCA7, ABCG1, ABCG2 and ABCG5, their regulating genes LXRα, PPARγ, SREBP1 and the milk proteins lactoferrin and α-lactalbumin were assessed. A significantly enhanced expression in the dry period was observed for ABCA1 while a significant decrease of expression in this period was detected for ABCA7, ABCG2, SREBP1 and α-lactalbumin. ABCG1, ABCG5, LXRα, PPARγ and lactoferrin expression was not altered between lactation and dry period. These results indicate that candidate ABC transporters involved in lipid and cholesterol transport show differential mRNA expression between lactation and the dry period. This may be due to physiological changes in the mammary gland such as immigration of macrophages or the accumulation of fat due to the loss of liquid in the involuting mammary gland. The current mRNA expression analysis of transporters in the mammary gland is the prerequisite for elucidating novel molecular mechanisms underlying cholesterol and lipid transfer into milk.

Twenty-three strains of lactic acid streptococci were shown to be types of Streptococcus cremoris or Str. lactis by cultural, biochemical and serological means. The antibiotics produced by the cremoris strains could be differentiated readily from the lactis antibiotics, of which at least five different varieties are described. A cross-test and a resistant-strain test were used to differentiate the antibiotics.

Continuous measurements of curd-firming using a commercial vibratingreed viscometer and a pressure transmission system (PTS) developed at this Institute were compared both in the laboratory and during Cheddar cheesemaking. The coefficient of variation about the mean of the curd-firmness measured in reconstituted skim-milk 40 min after renneting was 3·5% with the viscometer and 2·6% with the PTS. The effects of changes in conditions on the curd-firming rate of raw whole milk were determined. As the rennet concentration was raised the rates increased linearly as measured by the viscometer, but non-linearly as measured by the PTS. Addition of CaCl2 increased the rates measured by both instruments rapidly at first then more slowly at higher levels. Raising the temperature increased the rate exponentially in the case of the viscometer but more slowly with the PTS. With both instruments the curd-firming rates of milk at pH 5·8 were 6·5 times those at pH 6·7 but the rates fell slightly at pH 5·6. In experimental cheesemaking, the mean readings of both instruments at the subjectively determined cutting time of the curd had the same coefficient of variation.

The commercial viscometer is probably more suitable for laboratory investigations of the earlier stages of the coagulation of milk by rennet whilst the PTS may prove the more useful in indicating the optimum cutting time of the curd during cheesemaking.

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.

The objective of this study was to evaluate the effect of dietary supplementation with selenium (Se) and vitamin E (VitE) on milk yield, composition and renneting parameters in dairy Jonica breed goats. Forty multiparous lactating goats fed the same basal diet were randomly allocated to 1 of 2 dietary treatments: for 135 days, the experimental period. Basal diet was composed by ad libitum mixed vetch-oat hay and a definite amount of a pelleted concentrate. Dietary treatments included: (1) the control diet containing background Se and VitE only, and (2) the experimental diet containing sodium selenite as the Se supplement in concentrate (0·20 mg/head per day of Na-selenite and 20 mg/day per head of VitE). During the trial, no significant differences (P>0·05) were registered in dry matter intake and body weight gain among groups. Goats fed Se-VitE diet showed the highest milk production (P<0·05), and fat (P<0·01) and protein (P<0·05) yields and percentages. Somatic cell count were significantly lower in Se-VitE diet compared with control group (P<0·05). Significant differences (P<0·05) were observed in milk renneting properties. Based on our results, it was concluded that dietary supplementation with SE and VitE led to an increase of milk production and quality in Jonica goat, with positively improvement in milk coagulation aptitude.

Total and differential cell counts were obtained for 1710 samples of milk taken from cows in which the stage of lactation was known. A bacteriological examination of the samples was also made. The total and differential cell counts considered together showed no marked advantage over the total cell count alone in the diagnosis of mastitis, except in milk of late lactation.

One of the most important stages governing the accuracy of lactose determinations in milk is the preparation of the protein-free serum. Factors influencing the lactose content of the serum are: (1) the complete precipitation of protein, (2) the formation of lactose-protein complexes, and (3) the degree of hydration of the protein coagulum.

Experiments are described which show how these factors are influenced by different clearing agents operating at different pH values. On the basis of the results obtained a reagent containing zinc acetate, phosphotungstic acid and acetic acid is suggested; it reduces to a minimum any errors introduced by the above factors.