Milk Lactose Levels Research Articles

The Relation between Milk Lactose Concentration and the Rumination, Feeding, and Locomotion Behavior of Early-Lactation Dairy Cows.

This study hypothesizes that higher in-line milk lactose concentrations are indicative of enhanced dairy cow behaviors-including increased rumination, feeding, and locomotion activities-reflecting superior overall health and well-being. It posits that fluctuations in milk lactose levels have a substantial impact on the physiological and behavioral responses of dairy cows, thereby affecting their milk yields and compositions. Each cow's milk lactose, fat, protein, and fat-to-protein ratio were continuously monitored using the BROLIS HerdLine in-line milk analyzer (Brolis Sensor Technology, Vilnius, Lithuania). The RumiWatch noseband sensor (RWS; ITIN + HOCH GmbH, Fütterungstechnik, Liestal, Switzerland) was employed to measure the biomarkers of the rumination, feeding, and locomotion behavior. The measurements were recorded over 5 days at the same time (during morning milking). A total of 502 cows were examined. During these 5 days, 2510 measurements were taken. Based on the lactose content in their milk, the cows were divided into two categories: the first group consisted of cows with milk lactose levels below 4.70%, while the second group included cows with milk lactose levels of 4.70% or higher. Our study showed that cows with higher milk lactose concentrations (≥4.70%) produced significantly more milk (16.14% increase) but had a lower milk protein concentration (5.05% decrease) compared to cows with lower lactose levels. These cows also exhibited changes in rumination and feeding behaviors, as recorded by the RWS: there was an increase in the mastication and rumination behaviors, evidenced by a 14.09% rise in other chews and a 13.84% increase in rumination chews, along with a 16.70% boost in bolus activity. However, there was a notable 16.18% reduction in their physical activity, as measured by the change in time spent walking.

Evaluation of milk lactose levels for early diagnosis of mastitis

Evaluation of milk lactose levels for early diagnosis of mastitis

Relationship between Temperament and Stage of Lactation, Productivity and Milk Composition of Dairy Cows.

Simple SummaryCattle temperament can be described as a response to changes in the environment and is crucial for successful herd management using innovative technologies. Despite the economic aspects of animal productivity and welfare, there is still a lack of objective evidence for a wider use of temperament in dairy cattle breeding programmes. The aim of this study was to evaluate the relationship between cow temperament and milk indices describing cow productivity, metabolic status and mastitis resistance. The coefficient of heritability of temperament was determined. Only a small part of the phenotypic changes in this indicator in the analysed population was associated with genetic factors; however, the correlation of cow temperament with milk lactose and somatic cells suggests that temperament could be used in sustainable breeding programmes, giving priority to animal welfare and health. A statistically significant decrease in temperament scores with increasing lactation periods was only found in primiparous cows. It is also argued that changes in milk production, milk composition and quality associated with mastitis and a cow’s metabolic status should be taken into account when assessing the cow’s temperament, as these factors can affect the welfare and behaviour of an animal, and therefore the expression and intensity of their reaction to their environment.The aim of this study was to assess the relationship between temperament and milk performance in cows at different stages of lactation, describing their productivity, metabolic status and resistance to mastitis. This study showed that with increasing lactation, cows’ temperament indicators decreased (p < 0.001) and they became calmer. The highest temperament score on a five-point scale was found in cows between 45 and 100 days of lactation. In the group of pregnant cows, we found more cows (p = 0.005) with a temperament score of 1–2 compared with non-pregnant cows A normal temperament was usually detected in cows with lactose levels in milk of 4.60% or more and when the somatic cell count (SCC) values in cow milk were <100,000/mL and 100,000–200,000/mL, with a milk fat-to-protein ratio of 1.2. A larger number of more sensitive and highly aggressive cows was detected at a low milk urea level. In contrast to a positive phenotypic correlation (p < 0.05), this study showed a negative genetic correlation between the temperament of cows and milk yield (p < 0.001). Positive genetic correlations between temperament scores and milk somatic cells (p < 0.001) and milk fat-to-protein ratio (p < 0.05) were found to indicate a lower genetic predisposition in cows with a calmer temperament to subclinical mastitis and ketosis. On the other hand, the heritability of temperament (h2 = 0.044–0.100) showed that only a small part of the phenotypic changes in this indicator is associated with genetic factors.

Milk Lactose as a Biomarker of Subclinical Mastitis in Dairy Cows.

Simple SummaryEarly bovine subclinical mastitis detection may improve treatment strategies and milk yield and reduce the use of antibiotics. Scientific research is therefore focusing on the identification of new and less expensive biomarkers. One of the biomarkers with the greatest potential is milk lactose. To establish whether lactose could be used as an indicator for subclinical mastitis, milk samples from seventy-two herds were screened for bovine subclinical mastitis agents. This study evaluated the prevalence of subclinical mastitis pathogens, their seasonal occurrence, and the relationship with milk lactose concentration. Milk samples were mostly found to be infected with mixed microbiota, coagulase-negative Staphylococcus and Staphylococcus aureus. Yeast, Enterococcus spp. and coliform bacteria such as Escherichia coli were found during the outdoor grazing period. Increases in somatic cell count and decreases in lactose concentration were directly related to the presence of bovine subclinical mastitis agents. These findings suggest that changes in lactose content could be tracked as a diagnostic method in subclinical mastitis prevention in cows.Bovine subclinical mastitis can cause great harm to dairy herds because of its negative impact on milk production and quality and cow health. Improved diagnostic tools are needed to maximise the control of subclinical mastitis distribution and ensure the high quality of milk as an industrial product. Between 2015 and 2020, seventy-two dairy herds were screened for bovine subclinical mastitis causative agents to identify the relationship between seasons, lactose levels and subclinical mastitis infection. The predominant species found in the milk samples were mixed microbiota, coagulase-negative Staphylococcus and Staphylococcus aureus. Yeasts were found exclusively in autumn, while Enterococcus spp. and Escherichia coli were only found in summer and autumn. A negative correlation was detected between milk lactose and number of somatic cells in milk (−0.471; p < 0.001). The lactose levels in milk were closely associated with the prevalence (%) of subclinical mastitis pathogens, such as Streptococcus agalactiae (y = −1.8011x + 10.867, R2 = 0.9298), Staph. aureus (y = −3.5216x + 25.957, R2 = 0.8604) and other Streptococci (y = −0.5956x + 7.6179, R2 = 0.6656). These findings suggest that milk lactose may be used as a biomarker of suspected udder inflammation in modern health prevention programmes for cows to reduce the prevalence of subclinical mastitis pathogens in dairy cattle herds.

Inline Milk Lactose Concentration as Biomarker of the Health Status and Reproductive Success in Dairy Cows

In this study, cow reticulorumen content pH and temperature together with the activity were registered using smaXtec boluses, specially designed for animal care. Body weight, rumination time, milk fat/protein ratio, milk yield, milk lactose, milk electrical conductivity, milk somatic cell count and consumption of concentrated feed were registered by Lely Astronaut® A3 milking robots. The cows in this study were assigned into two groups according to the milk lactose concentration: group 1—milk lactose &lt; 4.70% (n = 20), group 2—milk lactose ≥ 4.70% (n = 15). The following cows were further classified according to milk fat and protein ratio: F/P &lt; 1.2 (class 1), F/P = 1.2 (class 2) and F/P &gt; 1.2 (class 3). According to our results, we can conclude that inline registered milk lactose concentration can be used to indicate the health status and reproductive success of fresh dairy cows. Cows with an increased lactose concentration (≥4.70%) showed more activity (54.47%) and had less risk of mastitis (determined by lower milk electrical conductivity (EC) and somatic cell counts (SCC)) and metabolic disorders, determined by milk F/P. A higher glucose concentration was also apparent in the cows with higher lactose concentration. Registered lower levels of milk lactose can be used for early identification of metabolic disorders and mastitis (set at milk SCC ≥ 100 thousand/mL). Lactose levels in cows’ milk were positively associated with their reproductive success.

Effects of indirect indicators of udder health on nutrient recovery and cheese yield traits in goat milk

In dairy goats, very little is known about the effect of the 2 most important indirect indicators of udder health [somatic cell count (SCC) and total bacterial count (TBC)] on milk composition and cheese yield, and no information is available regarding the effects of lactose levels, pH, and NaCl content on the recovery of nutrients in the curd, cheese yield traits, and daily cheese yields. Because large differences exist among dairy species, conclusions from the most studied species (i.e., bovine) cannot be drawn for all types of dairy-producing animals. The aims of this study were to quantify, using milk samples from 560 dairy goats, the contemporary effects of a pool of udder health indirect indicators (lactose level, pH, SCC, TBC, and NaCl content) on the recovery of nutrients in the curd (%REC), cheese yield (%CY), and daily cheese yields (dCY). Cheese-making traits were analyzed using a mixed model, with parity, days in milk (DIM), lactose level, pH, SCC, TBC, and NaCl content as fixed effects, and farm, breed, glass tube, and animal as random effects. Results indicated that high levels of milk lactose were associated with reduced total solids recovery in the curd and lower cheese yields, because of the lower milk fat and protein contents in samples rich in lactose. Higher pH correlated with higher recovery of nutrients in the curd and higher cheese yield traits. These results may be explained by the positive correlation between pH and milk fat, protein, and casein in goat milk. High SCC were associated with higher recovery of solids and energy in the curd but lower recovery of protein. The higher cheese yield obtained from milk with high SCC was due to both increased recovery of lactose in the curd and water retention. Bacterial count proved to be the least important factor affecting cheese-making traits, but it decreased daily cheese yields, suggesting that, even if below the legal limits, TBC should be considered in order to monitor flock management and avoid economic losses. The effect of NaCl content on milk composition was linked with lower recovery of all nutrients in the curd during cheese-making. In addition, high milk NaCl content led to reductions in fresh cheese yield and cheese solids. The indirect indicators of the present study significantly affected the cheese-making process. Such information should be considered, to adjust the milk-to-cheese economic value and the milk payment system.

&lt;b&gt;Gir and Guzerat cow milk production and composition according to lactation stage, somatic cell count, physiological state and body condition

ABSTRACT. This work was realized to evaluate lactation stage, physiological state, somatic cell count (SCC) and body condition score (BCS) on production and composition of cow's milk from Gir and Guzerat breeds were studied. Ninety-eight cows were analyzed and classified according to their physiological state, lactation stage, SCC and BCS. Milk production was weighed monthly to obtain production data. Composed samples were collected in vials containing preservatives and sent to the laboratory for analysis. Data were used for statistic descriptive analysis and analysis of variance. Higher milk production in the first 60 days of lactation was observed. Fat, protein and total solids concentration increased according to the increase of days in milk; while lactose concentration decreased. Higher levels of fat, protein and total solids in milk of non-pregnant cows were observed; while pregnant cows had higher daily production and higher lactose content in their milk. Higher lactose levels in milk were observed in animals with lower SCC. The BCS had no effect on milk composition or on somatic cell count. Zebu cow milk production and composition are influenced by lactation stage, physiological state and SCC.

Effect of curd washing on composition, lactose metabolism, pH, and the growth of non-starter lactic acid bacteria in full-fat Cheddar cheese

Cheddar cheese was manufactured in triplicate from mid-lactation milk and analysed over a 270-day ripening period. The curd was washed in the cheese vat to give target levels of lactose plus lactic acid in cheese moisture (LLAMc) in the final cheese of 5.3 (control), 4.5, 4.3 and 3.9% (w/w); these values correspond to the expected LLAMc levels in non-washed cheeses made from milk with lactose levels of 4.8 (control), 4.6, 4.3 and 3.8% (w/w), respectively. Increasing curd washing from 0 to 33% of milk volume significantly reduced mean levels of total lactate and LLAMc over the ripening period. Conversely, it increased the mean cheese pH by ∼0.3–0.4 at times≥90 days. The LLAMc was ∼1.0–1.6 units lower than predicted based on levels of milk lactose and curd washing. Otherwise, alteration of curd washing generally did not affect gross composition or microbiology of the cheese.

Effects of Recombinant Human Prolactin on Breast Milk Composition

The objective of this study was to determine the impact of recombinant human prolactin (r-hPRL) on the nutritional and immunologic composition of breast milk. We conducted 2 trials of r-hPRL treatment. In the first study, mothers with documented prolactin deficiency were given r-hPRL every 12 hours in a 28-day, open-label trial. In the second study, mothers with lactation insufficiency that developed while they were pumping breast milk for their preterm infants were given r-hPRL daily in a 7-day, double-blind, placebo-controlled trial. Breast milk characteristics were compared before and during 7 days of treatment. Among subjects treated with r-hPRL (N = 11), milk volumes (73 ± 36 to 146 ± 54 mL/day; P < .001) and milk lactose levels (155 ± 15 to 184 ± 8 mmol/L; P = .01) increased, whereas milk sodium levels decreased (12.1 ± 2.0 to 8.3 ± 0.5 mmol/L; P = .02). Milk calcium levels increased in subjects treated with r-hPRL twice daily (2.8 ± 0.6 to 5.0 ± 0.9 mmol/L; P = .03). Total neutral (1.5 ± 0.3 to 2.5 ± 0.4 g/L; P = .04) and acidic (33 ± 4 to 60 ± 6 mg/L; P = .02) oligosaccharide levels increased in r-hPRL-treated subjects, whereas total daily milk immunoglobulin A secretion was unchanged. r-hPRL treatment increased milk volume and induced changes in milk composition similar to those that occur during normal lactogenesis. r-hPRL also increased antimicrobially active oligosaccharide concentrations. These effects were achieved for women with both prolactin deficiency and lactation insufficiency.

Disrupted secretory activation of the mammary gland after antenatal glucocorticoid treatment in sheep

Antenatal glucocorticoids are administered to women at risk of preterm delivery to prevent neonatal respiratory morbidity. The effects of exogenous glucocorticoids on the development of lactation are unknown. This study investigated the effects of a single dose of antenatal glucocorticoids on secretory activation in sheep before and after parturition. Pregnant ewes (N=36) were randomised to receive either medroxyprogesterone acetate (MPA) at 118 days of pregnancy and betamethasone at 125 days (BETA group), MPA at 118 days and saline at 125 days (MPA group) or saline at 118 and 125 days (SALINE group). The concentration of lactose, progesterone, cortisol and prolactin in maternal plasma was measured during pregnancy. After term parturition, the concentration of lactose in milk and maternal plasma was measured daily for 5 days. Lambs were weighed at birth and at 5 days of age; milk volume was measured on day 5. The concentration of lactose in maternal plasma increased significantly after betamethasone administration, corresponding to a fall in plasma progesterone. No changes in lactose were observed in MPA or SALINE ewes. Transient decreases in cortisol and increases in prolactin were observed in the BETA group, but not in either the MPA or SALINE group. After parturition, BETA ewes experienced reduced milk yield and lamb weight gain, and delayed increases in milk lactose levels compared with MPA and saline controls. This study demonstrated that, in sheep, antenatal glucocorticoid administration disrupted secretory activation, causing precocious mammary secretion before parturition and compromising postpartum milk production and lamb growth.

Effect of Preterm Birth and Antenatal Corticosteroid Treatment on Lactogenesis II in Women

The onset of copious milk secretion after birth is known as lactogenesis II. The objective of this study was to investigate the effect of preterm birth and antenatal corticosteroids on the timing of lactogenesis II after birth. Women who had received antenatal betamethasone treatment and were expressing for a preterm infant whose gestational age was <34 weeks (N = 50) were included. On days 1 to 10 postpartum, participants measured the volume of milk expressed in 24-hour periods and collected milk samples. Lactose and citrate levels were analyzed in the milk. The gestational age at delivery was 31 weeks (range: 24.2-33.7). Milk volume was recorded by 46 women on 320 expression days and was positively associated with gestational age. Gestational age modified the effect of interval between betamethasone administration and delivery on milk volume. At gestational age 28 to 34 weeks, women who delivered 0 to 2 days after betamethasone treatment obtained significantly greater volumes than women who delivered 3 to 9 days after treatment. Milk samples (N = 324) were collected by 42 mothers. Mean +/- SD lactose and citrate levels were 156.800 +/- 36.217 and 3.458 +/- 1.442 mM, respectively. There was a significant positive effect of gestational age on milk lactose levels but not citrate levels. Betamethasone treatment did not alter lactose or citrate levels in milk. Delivery at extremely preterm gestational ages caused a significant delay in the onset of lactogenesis II. The volume of milk was reduced further when antenatal corticosteroids were administered between 28 and 34 weeks' gestation and delivery occurred 3 to 9 days later. In view of the advantages of mothers' own milk, additional support with lactation is recommended for mothers of preterm infants, particularly those who have been treated with corticosteroids before the delivery.

Dose dependent changes in inflammatory parameters in the milk of dairy cows after intramammary infusion of lipopolysaccharide

The goal of this study was to evaluate the dose dependent changes in common milk and blood parameters for udder health after an intramammary (IM) infusion of five different doses of lipopolysaccharide (LPS, 100, 50, 25, 12.5 and 6.25 &amp;mu;g, respectively). Ten Holstein Friesian cows randomly divided into five groups of 2 cows each were IM infused into one quarter with one LPS dose dissolved in 10 ml of saline. The contralateral quarter was infused with 10 ml saline (9 g/l). Milk samples were taken immediately before and 12, 24, 36, 48 and 60 hours after the treatment. All milk samples were analysed for somatic cell counts (SCC), lactose, sodium (Na), chloride (Cl) and electrical conductivity (EC). Two blood samples were taken immediately after milking for analysing leukocytes (WBC), polymorphonuclear neutrophils (PMN), Na and Cl. The SCC increased maximal at 12 hours after the LPS challenge and differed among LPS doses, as well as the area under curve from 0 to 36 hours (AUC 0&amp;minus;36 h). There were no significant differences among LPS doses in lactose levels for the regression at 12 hours and AUC 0&amp;minus;36 h. Lactose levels in milk from quarters receiving the lowest dose of LPS were lowest after 24 hours, whereas in all other groups lactose levels decreased maximal within the first 12 hours. The regression at 12 hours as well as the AUC 0&amp;minus;36 h showed significant changes for Cl levels but not for Na and EC, respectively. Amongst all groups EC increased maximal within 12 hours and peak EC showed dose dependent differences with highest values at the highest LPS dose. There were no dose differences in WBC. Blood electrolytes showed only tendentially dose dependent differences for blood Na in AUC 0&amp;minus;36 h. The results were possibly due to a great individual variance amongst all cows. In conclusion there are dose dependent differences in the response to LPS especially in milk parameters, which are likely caused by a greater tight junction damage by higher LPS doses. 100 &amp;mu;g LPS seems to be a threshold between low and high doses of LPS. All doses used in this study induced signs of mastitis but there might be a low dose of LPS with only an enhancing effect on mammary gland immune status without inducing mastitis symptoms. This needs to be investigated for developing new ways of mastitis prophylaxis.

Influence of space allowance and milk yield level on behaviour, performance and health of dairy cows housed in strawyard and cubicle systems

Two experiments were conducted to study the effects of two space allowances and two initial milk yield levels on indicators of welfare relating to behaviour, performance and health of dairy cows housed in strawyards (experiment 1), and cubicles (experiment 2). The experiments were carried out with 24 and 32 Holstein Friesian cows, respectively, and had changeover designs each with two periods of 4 weeks, and two replicates of six and eight cows in each treatment. The respective total and bed space allowances per cow for strawyards were, 13.5 and 9.0 m 2 for high, and 6.7 and 4.5 m 2 for low space allowance. For cubicles, respective allowances per cow were 10.6 and 3.9 m 2 for high and 7.75 and 2.3 m 2 for low. Space allowance had no significant effect on milk production, liveweight change, condition score, feed intake or on total time spent feeding and lying. In strawyards, cows were dirtier ( P<0.01) at the low space allowance and milk lactose levels were lower ( P<0.01), indicating some prevalence of mastitis. In cubicles, agonistic interactions were greater ( P<0.001) at the low space allowance and the diurnal pattern of lying was disrupted, especially for high yielding cows. High milk yield cows in strawyards had lower lying times ( P<0.001) and lying synchrony ( P<0.01) than low yielding cows. Higher feed intakes of high yielding cows ( P<0.001) resulted in higher ruminating times ( P<0.001) in both experiments and higher feeding times in experiment 1 ( P<0.001) than for low yielding cows. It is concluded that for strawyards, cleanliness of the cows is a key welfare indicator, and can be controlled by management of the straw beds. Total lying time and lying synchrony are also key factors of welfare, and have particular relevance for cubicle systems where lower values were recorded. High yield dairy cows had a shorter lying time than low yield cows, and there was no evidence that high and low yield cows respond differently to changes in space allowance, indicating that their housing requirements are similar.

Effect of decreased milking frequency of cows in late lactation on milk somatic cell count, polymorphonuclear leucocyte numbers, composition and proteolytic activity.

The effects of reducing the frequency of milking of cows in late lactation on milk somatic cell count (SCC), polymorphonuclear leucocyte (PMN) content, chemical composition and proteolytic activity were investigated. Intermittent milking is frequently practised by Irish farmers in late lactation, and the objective of this study was to determine whether this procedure could be linked to altered quality of milk. Seventeen Holstein Friesian cows in late lactation (> 215 d in milk) were assigned to two treatment groups, and were either milked twice a day until drying-off (control group) or milked intermittently as the yield fell (test group). Milk composition and enzymic characteristics were measured on two occasions. At the first sampling, day 7, test cows were on once daily milking and at the second, day 15, the test cows were being milked every second day. Milk yields were significantly lower in test than control animals and decreased between days 7 and 15 in both groups. Milk SCC and PMN levels were increased on reducing milking frequency and, at day 15, the increase was not linked to decreased milk yield. Milk lactose levels were significantly decreased and pH, alpha-lactalbumin levels, plasmin activity and plasminogen activity significantly increased by reducing milking frequency. In conclusion, reduced frequency of milking in late lactation leads to the production of milk that is abnormal in character and this may be linked to reduced quality of dairy products manufactured from such milk.

Lactose synthesis and secretion by mammary epithelial cells in vitro, a comparative study

1. 1. A method is reported for studying lactose metabolism using dispersed mammary epithelial cells (MEC) in vitro. 2. 2. Lactose synthesis in the mouse was apparent during late pregnancy and continued throughout lactation. Rates of lactose synthesis and secretion and cell lactose contents were proportional to each other and were dependent upon the stage of lactation. 3. 3. Comparative analysis of dispersed MEC of other lactating animals revealed the following ranking of relative rates of lactose synthesis and secretion and of cell lactose contents: guinea pig, early lactation (EL) > rat, mid-lactation (ML) > rabbit (ML) = mouse (ML) > hamster (ML) > mouse (EL). 4. 4. Rates of lactose synthesis and secretion and cell lactose levels were proportional to the lactose concentration of each species' milk. In EL and ML mice, calculated Golgi secretory vacuole lactose concentrations closely approximated milk lactose levels. 5. 5. It is proposed that milk lactose levels are established by and are equivalent to the lactose concentrations of the primary fluid secretion of MEC, i.e. the fluid contents of the Golgi vacuole.

Milk composition and thiamine transfer in thiamine deficient rats

Milk composition was determined in rats maintained on a thiamine deficient diet from the 10th day of pregnancy. Percentage of thiamine transfer was reduced after the 14th postpartum day. Milk composition of thiamine deficient dams 18 days postpartum revealed similar protein and amino acid levels in both thiamine deficient and control rats, whereas milk protein fractions showed some differences. Milk lactose levels were depressed in thiamine deficient rats. Fatty acid content was higher in milk of thiamine deficient than in pair fed and adlibitum controls. The supply of a larger proportion of calories from lipids rather than carbohydrates may have clinical significance.