Disposition kinetics of lactoferrin in milk after intramammary administration

Disposition kinetics of lactoferrin (Lf) purified from cheese whey was studied in the milk of Finnish Ayrshire cows after intramammary administration of 1 g of Lf into one udder quarter. Intramammary administration of 1 g of Lf increased Lf concentration in milk for several hours. Mean elimination half-life of Lf was 2.2 h and a mean maximum concentration of 6.3 g/L was reached between 1 and 4 h. After 8 h of administration, Lf concentrations in milk decreased to almost the same level as before the infusion. Forty-eight hours postinfusion, the mean Lf concentration was again higher than in the milk samples taken before the infusion of Lf, being on average 1.5 g/L. Lactoferrin caused some local tissue irritation in the udder quarter. Severity of the irritation reactions varied between cows. The udder quarters of primiparous cows reacted faster than those of multiparous cows, but irritation reactions decreased more rapidly in the older cows than in primiparous cows. The cows had no general signs such as fever or anorexia. The somatic cell count returned to baseline level 4 days after the administration.     

The interrelationships between milkability traits and subclinical mastitis in cows

The investigation was conducted during 2005-2006 on 4010 dairy cows. Having performed statistical data analysis, we determined that the lowest somatic cell count (SCC) in Red and Red-White cow population was obtained when the milking time was 5-6 min., milking speed was higher than 1.5 kg/min., high milk flow was from 2.51 to 4 kg/min., and in Black-White cow population having a milking time was higher than 7 min., milking speed was from 1.01 to 2 kg/min., a high milk flow --from 2.01 to 4 kg/min. (p<0.001). In Red and Red-White cow population with subclinical mastitis, milking time was longer and milking speed was slower than in healthy cows. High milk flow values were least in healthy Black-White cow population. This determines a more equal milk flow which is desired in milking cows mechanically. Most sensitive to udder infection are 1st lactation cows which have a higher milk flow. A larger phenotype correlation coefficient in Red and Red-White cow population was between the SCC and milking time (-0.089, p<0.01) and between high milk flow (0.086, p<0.01) and milk yield (-0.071, p<0.05). However in Black-White cow population, correlation was found between SCC and milk yield (-0.117, p<0.01) and milking speed (-0.110, p<0.01). Contagious mastitis pathogens were identified in Red and Red-White cow milk samples primarily from productive cows having a milking speed of 1.01-1.5 kg/min., and in Black-White cow population having a milking speed of 1.51-2.0 kg/min.     

Effects of autogenous toxoid-bacterin in lactating cows with Staphylococcus aureus subclinical mastitis

To evaluate clinical effects of autogenous toxoid-bacterin treatment for Staphylococcus aureus subclinical mastitis in lactating cows, 22 cows which had at least one S. aureus infected quarter were selected from among cows at a S. aureus prevalent dairy farm. Eleven cows were injected with their own autogenous toxoid-bacterin and the others were maintained as non-injected control. In the toxoid-bacterin injected group, 27% of infected quarters were cured during the 12-week trial, compared to 5% in the control group. New intramammary infections with S. aureus were only detected in 3 quarters of the control group. Mean IgG antibody titer against S. aureus somatic antigens and alpha-toxin in serum and milk were significantly increased in the toxoid-bacterin injected group (p<0.05) and remained higher than those of the control group which showed no significant changes (p<0.05). In contrast to the control group, from 3 weeks after the second injection of the toxoid-bacterin injected group, mean S. aureus cfu/ml in milk samples from injected quarters with S. aureus was significantly decreased until the end of the study (p<0.05). In the toxoid-bacterin injected group, significant decreases of mean SCC were detected from milk samples from infected quarters with S. aureus from week 7 to week 10 (p<0.05). These data show that autogenous toxoid-bacterin treatment against S. aureus subclinical mastitis in lactating cows may increase the cure rate of the infections, reduce the severity of the infections and also prevent occurrence of the new infections.     

酵母培养物益康XP对奶牛血浆内毒素含量及其它指标影响的研究

选取泌乳初期(泌乳天数<40d)健康奶牛12头,按胎次、泌乳天数和产奶量相同或相似的原则进行配对,分为试验组和对照组。两组日粮组成相同,但试验组牛每天添加益康XP(剂量为试验第1-7d500g/头/d,从第8d后减少到120g/头/d,分两次饲喂)。试验期为60d。于试验前1d、试验第20d、40d、60d分别采血,用鲎试剂法测定血浆内毒素含量;定期测定日均产奶量、乳脂率、乳蛋白率和体细胞数;并记录情期受胎率及疾病发生情况。结果表明:试验组奶牛在试验后第20d、40d、60d血浆内毒素均极显著低于对照组(p<0.01);产奶量在第20d、60d显著高于对照组(p<0.05);两组奶牛乳脂率、乳蛋白率、体细胞数差异均不显著(p>0.05);试验组情期受胎率极显著高于对照组(p<0.01);在疾病发生率方面,试验组极显著低于对照组(p<0.01)。     

A method to estimate the somatic cell count of milk from a mastitic quarter using composite somatic cell count.

The purpose of the study was to estimate the extent to which one quarter could be inflamed relative to the other three quarters of a cow, given that knowledge only of the composite milk somatic cell count (SCC) was available. An algebraic relationship, which incorporated the parameters of composite milk SCC, production loss associated with composite milk SSC, SCC of milk from an inflamed quarter, and SCC from three non-inflamed quarters, was used to derive hypothetical estimates of the SCC in one inflamed quarter. A simple case was considered in which one quarter was mastitic, the SCC in milk of the noninflamed quarters was equal, and there was no production compensation by the noninflamed quarters. Previously published estimates were used for production loss associated with composite milk SCC. For moderate composite milk SCC (300,000-500,000 cells/mL) and low-to-moderate SCC in milk of noninflamed quarters (100,000 cells/mL), the SCC of milk from one inflamed quarter was predicted to be very high, ranging from about 1.26 million (log10 SCC = 6.1) to 6.3 million (log10 SCC = 6.8) cells/mL, and compatible with signs of clinical mastitis. These results suggest that in order to screen cows with clinical mastitis in only one quarter, composite milk SCC should be considerably lower than values presented previously by other investigators.     

Clinical acidosis in a Gippsland dairy herd

OBJECTIVE: To report on spontaneous clinical and subclinical acidosis in a large dairy herd, to evaluate the diets and feeding strategies involved, and to report on measures of rumen function in the cows affected. DESIGN: A Gippsland dairy herd was sampled as part of a wider randomised cross-sectional study that examined the prevalence, risk factors for, and effects of, acidosis on rumen function of dairy cattle. Three herds on the farm were involved in the study: the transition herd (cows 3 weeks prior to calving), the very fresh lactating herd (1 < days in milk < 10, herd 1) and the fresh lactating herd (10 < days in milk < 120, herd 2) including a small lame herd fed separately. The transition cows were fed 2 kg dry matter triticale per cow per day and hay with an estimated total dry matter intake of 4.8 kg per cow per day. The lactating cow diet included 6.75 kg dry matter triticale per cow per day with total concentrate fed being 8.1 kg dry matter per cow per day in the milking parlour. Silage, lucerne cubes, hay and pasture (herd 2 only) was also fed to the lactating cows with the estimated total dry matter intake for cows in herds 1 and 2 being 13.7 kg and 20.8 kg per cow per day respectively. Three primiparous and five multiparous cows in early lactation (< 100 days in milk) were randomly selected from each of two lactating herds: herds 1 and 2. Rumen fluid was sampled from each cow by both rumenocentesis and stomach tube. The rumenocentesis samples were tested for pH at the time of sampling. Stomach tube samples were frozen and subsequently tested for volatile fatty acid, ammonia, and D- and L-lactate concentration. RESULTS: In the very fresh herd, there was a high prevalence of severe lameness and scouring, coupled with a mean rumen pH 5.67, low mean total volatile fatty acid concentration 71.0 mM and high mean concentrations of L- and D-lactate, (7.71 mM and 7.31 mM), respectively. Cows in the fresh herd had moderate signs of scouring and lameness. A lame herd comprising approximately 50 cows separated from the fresh herd was also present on the farm. The mean rumen pH of the fresh herd was 5.74 and mean rumen concentrations of volatile fatty acids, ammonia, L- and D-lactate were within ranges considered normal. CONCLUSIONS: The transition diet failed to supply sufficient energy and protein for maintenance of cows of this live weight in late gestation. The diet fed to the very fresh herd was low in effective fibre and contained an excessive content of non-structural carbohydrate in the form of processed, rapidly fermentable grain. The sudden change from the transition diet to the diet fed to the very fresh herd probably also precipitated the outbreak of acidosis. This case report provides unique detail, including information on diets and rumen parameters, of an outbreak of acidosis in a pasture-fed herd.     

Milk prostaglandins and electrical conductivity in bovine mastitis

Prostaglandin (PG) levels in milk samples from healthy and mastitic cows were determined by radioimmunoassay. In composite milk the PG levels were rather high both in healthy and mastitic samples, and the only significant difference was in thromboxane B₂ (TXB). In quarter milk samples classified according to the degree of mastitis by use of somatic cell counts, PGE₂ was 40, PGF₂15, and TXB₂ 44 per cent higher respectively in affected samples. PG levels were in good correlation with somatic cell counts (r=0.63–0.68, p<0.01) and electrical conductivity (r=0.36–0.52, p<0.01), two established criteria for diagnosis of mastitis. PGE₂ also correlated with protein, TXB₂ with fat content. PGF₂ was in a negative correlation with milk yield. The good correlation of PGs with somatic cell counts and electrical conductivity suggests that PGs might be used as markers of mastitic inflammation.     

Efficacy of specific egg yolk immunoglobulin (IgY) to bovine mastitis caused by Staphylococcus aureus

The objective of this study was to estimate the efficacy of specific egg yolk immunoglobulin (IgY) to bovine mastitis caused by Staphylococcus aureus. Eighteen lactating cows with clinical mastitis and 18 lactating cows with experimental mastitis (1 quarter per cow) were randomly assigned to three treatments: IgY (20mg/ml) infusion, penicillin (100mg/ml) infusion and no infusion. Treatments for clinical mastitis and experimental mastitis were performed by a 6-day course of intramammary infusion with a dosage of 10ml at an interval of 12h. Milk samples were collected at morning milking time for testing color, clot, somatic cell counts (SCC) and bacterial count. For most of the cows treated with IgY and penicillin, the milk color and clot recovered to normal form during the therapy course. The milk SCCs and bacterial counts of treated cows decreased compared to those of untreated cows (p<0.05). The cure rates by IgY for experimental and clinical mastitis were 83.3% and 50%, respectively, and those by penicillin were 66.7% and 33.3%, respectively. These results showed the potential of specific IgY to be an alternative therapy for mastitis caused by S. aureus.     

A new diagnostic indicator using concanavalin a low-affinity lactoferrin levels in mammary gland secretion in mastitic drying cows

We examined the effective diagnostic indicator using the concanavalin A (Con A) low-affinity lactoferrin (Lf) to mastitic drying cows. The concentrations of both Lf and Con A low-affinity Lf in mammary gland secretions (MGSs) were lower than normal MGSs at the early and middle dry periods and colostrums. On the other hand, the levels of Con A low-affinity Lf in MGSs increased following the appearance of mastitis symptoms, and decreased when the mastitic symptoms were cured. Moreover, IgG1 concentrations of colostrums decrease on the quarters where a high level of Con A low-affinity Lf was determined after the onset of dry period. These results suggest that this method could be used as a useful indicator to mastitic drying cows.     

Pharmacokinetics of sodium cephapirin in lactating dairy cows

Sodium cephapirin was administered (10 mg/kg of body weight, IM) at 8-hour intervals in 4 consecutive doses to each of 6 lactating dairy cows. Blood, normal milk, mastitic milk, urine, and endometrial tissue samples were collected serially. Mean peak cephapirin concentrations in serum were 13.3 micrograms/ml 10 minutes after the 1st injection and were 15.8 micrograms/ml 20 minutes after the 4th injection (post[initial]injection hour [PIH] 24.33). The overall elimination rate constant value was 0.66/h and plasma clearance was 760 ml/h/kg. Mean peak cephapirin concentration in normal milk was 0.11 microgram/ml at PIH 2 and mean peak cephapirin concentration in mastitic milk was 0.18 microgram/ml at PIH 4. Cephapirin was not detected in the endometrium. The highest concentration of cephapirin in urine was 452 micrograms/ml, 2 hours after the 4th dose (PIH 26).     

益康XP对奶牛血浆内毒素含量及其他指标的影响

选取泌乳天数<40 d的健康奶牛 12头,按胎次、泌乳天数和产奶量相同或相似的原则,分为试验组和对照组。两组日粮组成相同,试验组牛每天添加益康XP的剂量为试验第1天至第7天500 g/(头·d),从第 8 天后减少到120 g/(头·d),分两次饲喂。试验期为60 d。于试验前 1 天,试验第 20 天,40天和第 60 天分别采血,用鲎试剂法测定血浆内毒素含量;定期测定日均产奶量、乳脂率、乳蛋白率和体细胞数;记录情期受胎率及疾病发生情况。结果表明,试验组奶牛在试验后第20天,第 40 天和第 60 天血浆内毒素均极显著低于对照组(P<0.01);产奶量在第20天,第60天显著高于对照组(P<0.05);两组奶牛乳脂率、乳蛋白率、体细胞数差异均不显著(P>0.05);试验组情期受胎率极显著高于对照组(P<0.01);在疾病发生率方面,试验组极显著低于对照组(P<0.01)。     

Association between Coxiella burnetii shedding in milk and subclinical mastitis in dairy cattle

The objective of this research was to explore the potential association between Coxiella burnetii shedding in milk and chronic subclinical mastitis in dairy cattle. In two separate studies, we identified an association between PCR-based detection of C. burnetii in milk and chronic subclinical mastitis in lactating dairy cows. These studies were conducted in a commercial dairy herd where there was ongoing intensive monitoring of subclinical mastitis by aerobic bacteriology, but no prior knowledge or management of C. burnetii infections. In a case-control study, quarter level C. burnetii status determined by real-time quantitative PCR (RT-qPCR) was strongly associated with chronic subclinical mastitis as measured by milk somatic cell counts. In a subsequent cross sectional study, 147 (45%) of 325 lactating cows were positive for C. burnetii by RT-qPCR of composite milk samples. In a generalized linear model, accounting for the effect of covariates including aerobic intramammary infection status, C. burnetii PCR status was a significant predictor of linear somatic cell count score. In agreement with a small number of previous reports, this research provides evidence that there may be mammary gland specific manifestations of C. burnetii infections in dairy cattle.     

Induction of Escherichia coli mastitis in cows fed selenium-deficient or selenium-supplemented diets

Ten Holstein heifers were fed a selenium-deficient (SeD) diet (0.04 mg of Se/kg on a total ration dry-matter basis) 3 months before calving and throughout their first lactation. A selenium-supplemented (SeS) diet (2 mg of Se/head/d) was fed to a group of 10 heifers. In about the 14th week of lactation, the cows were challenge-exposed to Escherichia coli by administering 15 to 40 colony-forming units (CFU) into 1 mammary gland. Selenium concentration (microgram/ml) in blood around the time of challenge exposure was 0.033 +/- 0.002 (mean +/- SEM) in SeD and 0.132 +/- 0.006 in SeS cows. Infections were established in all challenge-exposed quarters. The frequency of quarter atrophy and agalactia, and reduction in whole-udder milk yield in the first 4 days after challenge exposure, were greater (P less than 0.05) in the SeD cows. Log10 peak bacterial concentrations in milk were higher (P less than 0.05) in SeD (7.63 +/- 0.34 CFU/ml) than in SeS cows (5.57 +/- 0.66 CFU/ml). Mean log bacterial concentration was significantly higher (P less than 0.05) from 12 to 20 hours after challenge exposure in SeD than in SeS cows. Duration of infection was significantly greater (P less than 0.05) in SeD (162.0 +/- 12.0) than in SeS cows (114.4 +/- 18.0 hours). Milk somatic cell counts increased significantly more slowly (P less than 0.05) in SeD than in SeS cows from 8 to 16 hours after challenge exposure. Ratios of milk somatic cells to bacteria in milk were significantly lower (P less than 0.05) in SeD than in SeS cows at 12 and 16 hours after challenge exposure.     

Effect of Infusing Lactoferrin Hydrolysate into Bovine Mammary Glands with Subclinical Mastitis

The therapeutic effect of administering lactoferrin hydrolysate (LFH) into the mammary glands of cows with subclinical mastitis was evaluated. Seven millilitres of a preparation of LFH (7% protein) was infused into 35 quarters of 25 cows with subclinical mastitis. The numbers of bacteria in the milk from infected quarters decreased, and bacteria disappeared by the 14th day after the administration of LFH. The mean somatic cell counts (SCC) peaked one day after administration of LFH and the counts were significantly (p<0.01) decreased on days 7, 14 and 21 compared to those before the administration of LFH. The mean lactoferrin concentration in the milk peaked on days 2 or 3 and then gradually decreased to day 14, returning to the level before the administration of LFH. It appears that administration of LFH may have a therapeutic effect when infused into the quarters of cows with subclinical mastitis.     

Indicators of inflammation to evaluate the recovery from acute bovine mastitis

The recovery of 39 mastitic cows was evaluated using alpha 1-antitrypsin, N-acetyl-beta-D-glucosaminidase (NAGase), plasmin and somatic cell counting for monitoring the inflammatory process. Bacteriological investigation was undertaken during the acute phase and at days 21 and 50 after treatment. In the quarters with a bacteriological cure the concentrations of all inflammatory markers in the milk returned to normal within three weeks. The quarters which harboured subclinical infection at days 21 and 50 after the onset of the disease showed higher values of the inflammatory parameters than uninfected, healed quarters. NAGase was the best predictor of the bacteriological status during the healing period (three weeks after therapy). The study suggests that NAGase determination in each quarter (with interquarter evaluation) possibly in conjunction with a bacteriological investigation three weeks after therapy, would be a good combination for assessing the outcome of treatment.     

Role of prostaglandins in pathogenesis of bovine mastitis induced by Escherichia coli endotoxin

Four doses (5 to 100 micrograms, 1 dose/quarter) of Escherichia coli endotoxin were introduced into lactating mammary glands of 2 cows. There was no effect on milk prostaglandin (PG) E2 concentration, except that the concentration was increased from 200 pg/ml of milk to 1,060 pg/ml at post-treatment hour (PTH) 8 in cow 1 and from 75 to 420 pg/ml at PTH 4 in cow 2 after the highest dose 100 micrograms. Endotoxin caused a dose-dependent increase in milk PGF2 alpha concentrations in both cows. After the highest dose, PGF2 alpha was maximally increased from 200 to 3,500 pg/ml at PTH 4 in cow 1 and from 250 to 2,000 pg/ml in cow 2 at PTH 8. The instillation of 50 micrograms of endotoxin in all 8 quarters of 2 more lactating cows caused no significant (P greater than 0.05) changes in milk PGE2 and thromboxane B2 concentrations, whereas milk PGF2 alpha was significantly increased from the base-line value of 642 to 2,683, 1,189, and 2,281 pg/ml at PTH 4, 8, and 12, respectively. The 6-keto-PGF1 alpha was also significantly increased from the base-line value of 305 to 871, 631, and 600 pg/ml at the corresponding times, respectively. A marked increase in vascular permeability, as judged by high concentrations of serum albumin in the whey, was observed as early as PTH 4 and peaked at PTH 12 followed by a gradual decline, although it remained significantly increased over the control for 48 hours after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Phmacodynamics and pharmacokinetics of carprofen, a non-steroidal anti-inflammatory drug, in healthy cows and cows with Escherichia coli endotoxin-induced mastitis

The pharmacodynamics of carprofen and its pharmacokinetics in plasma and milk of healthy cows and cows with endotoxin-induced mastitis were studied after a single intravenous dose of 0.7 mg/kg body weight. Carprofen was administered to five clinically healthy cows and to the same cows 3 weeks later, 2 h after intramammary infusion of endotoxin. Mastitis developed in all endotoxin-infused quarters. The pharmacokinetic characteristics of carprofen in healthy cows were a small volume of distribution (0.09 l/kg), a relatively low systemic clearance (2.4 ml/h kg), and a long elimination half-life (30.7 h). In the mastitic cows, systemic clearance (1.4 ml/h kg) was significantly lower (P less than 0.01), and elimination half-life (43.0 h) was significantly longer (P less than 0.01) than in the normal animals. Concentrations of carprofen in milk from healthy quarters were below the limit of detection for the assay (0.022 micrograms/ml). In milk from mastitic quarters, concentrations of carprofen increased up to 0.164 micrograms/ml during the first 12 h after induction of mastitis, but were less than 0.022 micrograms/ml at 24 to 48 h. Compared with the untreated mastitic controls, carprofen treatment significantly reduced heart rate (P less than 0.01), rectal temperature (P less than 0.001), quarter swelling (P less than 0.01) and other parameters measured. Local and systemic adverse reactions to carprofen were not observed.     

Concentrations of IL-6 in Serum and Whey from Healthy and Mastitic Cows

Inflammatory cytokines, such as interleukin (IL)-6, have been shown to reflect clinical signs in certain conditions in diseased animals. In this study, we quantified the IL-6 concentrations in the serum and milk whey from 94 dairy cows with acute clinical mastitis and 55 healthy lactating cows. The IL-6 concentrations in serum from mastitic cows were significantly higher on the first day of illness compared to those of normal cows. Higher concentrations of IL-6 were also detected in the whey from mastitic cows, whereas low concentrations of IL-6 were detected in both serum and whey samples from normal cows. IL-6 concentrations in the serum taken at the onset of illness from cows that later required euthanasia were significantly higher than those in samples from cows that later recovered. These results suggest that serum IL-6 concentrations may be of prognostic value in identifying cows with severe mastitis.     

The economic benefit of treating subclinical Streptococcus agalactiae mastitis in lactating cows

The economic benefits of treating lactating cows for Streptococcus agalactiae mastitis were studied at a large (689 milking cows) central California dairy. Postcure milk production of case cows (infected, treated, and cured) was compared with production of paired control cows (uninfected) and was matched for yield, days in milk, days in gestation, and parity. A simulation was used to plot expected lactation curves for mastitic cows (infected, not treated) with characteristics similar to those of each control cow, and these curves were compared with actual case-cow lactation curves. The difference in actual and expected production was used to calculate net economic benefits of treatment. Comparison of expected with actual production indicated a net benefit from treatment of $396/cow for cows treated in early lactation and $237 for cows treated in midlactation, but a net loss of $55 for cows treated in late lactation. Lactation number did not have a significant impact on economic benefits of treatment. In contrast to other studies indicating no economic benefit from treating mastitis during lactation, this study's positive results may have been attributable to the high cure rate (98%) and the subclinical form of mastitis being treated. Streptococcus agalactiae mastitis treatment during early and midlactation would appear to be an economically justifiable option for dairy managers.