Normal Quarters Research Articles

Systemic early warning systems for EU14 based on the 2008 crisis: proposed estimation and model assessment for classification forecasting

Abstract Reliable forecasts of an economic crisis well in advance of its onset could permit effective preventative measures to mitigate its consequences and become a valuable tool for banking regulation and macroprudential policy. Using the EU14 crisis of 2007–2008 as a template, we develop methodology that can accurately predict a banking crisis several quarters in advance in each country. The data for our predictions are standard, publicly available macroeconomic and market variables that are preprocessed by moving averages and filtering. The prediction models then utilize the filtered data to distinguish pre-crisis from normal quarters through standard statistical classification methodology plus one proposed method, enhanced by an innovative goodness-of-fit measure used in the estimation and in the threshold selection. Empirical results are quite satisfactory and can be used by policy makers, investors and researchers who are interested in estimating the probability of a crisis as much as one and a half years in advance in order to deploy prudential policies. Implications to bank regulatory policy are discussed.

Receiver operating characteristic analysis of milk lactosefor identification of mastitis in buffaloes

Receiver operating characteristic (ROC) analysis is a simple statistical tool used to classify a diagnostic indicator in terms of area under a ROC curve (AUC) and to develop potential threshold values of a diagnostic indicator. Milk lactose was analyzed by ROC analysis to see its accuracy to discriminate infected and healthy udder quarters, and to develope an optimum threshold value along with corresponding sensitivity (Se), specificity (Sp) and positive likelihood ratio (LR+) value. Data for the present study comprised of 1516 milk samples collected from Jaffrabadi buffaloes. Milk lactose was estimated by milk analyzer ‘LACTOSCAN’ and further samples were checked for sub-clinical mastitis by California mastitis test (CMT). The threshold values of milk lactose for identification of moderate and severe infection were found to be 5.31g% (Se, 58.82%; Sp, 58.28%) and 5.23g% (Se, 70.97%; Sp, 64.41%), respectively by ROC analysis. Milk samples with lactose content below 5.31g% were 1.41 times more likely come from moderately infected quarters (LR+ = 1.41); whereas, below 5.23g% were 1.99 times more likely come from severely infected quarters (LR+ = 1.99). The overall accuracy of milk lactose for discrimination of normal quarters from moderately infected quarters was 64% (AUC=0.64) and from severely infected quarters was 72% (AUC=0.72) (P<0.001). Thus, the present study indicated that milk lactose classified mastitic and healthy udder quarters in Jaffrabadi buffaloes with moderate accuracy.

Systemic Early Warning Systems for Eu15 Based on the 2008 Crisis

Reliable forecasts of an economic crisis well in advance of its onset could permit effective preventative measures to mitigate its consequences. Using the EU15 crisis of 2008 as a template, we develop methodology that can accurately predict the crisis several quarters in advance in each country. The data for our predictions are standard, publicly available macroeconomic and market variables that are preprocessed by moving averages and filtering. The prediction models then utilize the filtered data to distinguish pre-crisis from normal quarters through standard statistical classification methodology plus a proposed new combined method, enhanced by an innovative threshold selection and goodness-of-fit measure. Empirical results are very satisfactory: Country-stratified 14-fold cross validation achieves 92.1% correct classification and 85.7% for both true positive rate and positive predictive value for the EU15 crisis of 2008. Results will be of use to policy makers, investors, and researchers who are interested in estimating the probability of a crisis as much as one and a half years in advance in order to deploy prudential policies.

Effect of forelimb lameness on hoof kinematics of horses at a trot

To determine kinematic changes to the hoof of horses at a trot after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness values after perineural anesthesia. 6 clinically normal Quarter Horses. For each horse, a sole-pressure model was used to induce 3 grades (grades 1, 2, and 3) of lameness in the right forelimb, after which perineural anesthesia was administered to alleviate lameness. Optical kinematics were obtained for both forelimbs with the horse trotting before (baseline) and after induction of each grade of lameness and after perineural anesthesia. Hoof events were identified with linear acceleration profiles, and each stride was divided into hoof-contact, break-over, initial-swing, terminal-swing, and total-swing segments. For each segment, kinematic variables were compared within and between limbs by use of mixed repeated-measures ANOVA. During hoof-contact, the left (nonlame) forelimb hoof had greater heel-down orientation than did the right (lame) forelimb hoof, and during break-over, the nonlame hoof went through a larger range of motion than did the lame hoof. Maximum cranial acceleration during break-over for the lame hoof was greater, compared with that at baseline or for the nonlame hoof. Following perineural anesthesia, the sagittal plane orientation of the hoof during hoof-contact did not vary between the lame and nonlame limbs; however, interlimb differences in maximum cranial acceleration and angular range of motion during break-over remained. Results suggested that hoof kinematics may be useful for detection of unilateral, weight-bearing forelimb lameness in horses that are trotting.

Effect of forelimb lameness on hoof kinematics of horses at a walk

To determine kinematic changes to the hoof of horses at a walk after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness (baseline) values after perineural anesthesia. 6 clinically normal Quarter Horses. For each horse, a sole-pressure model was used to induce 3 grades of lameness in the right forelimb, after which perineural anesthesia was administered to eliminate lameness. Optical kinematics were obtained for both forelimbs with the horse walking before (baseline) and after induction of each grade of lameness and after perineural anesthesia. Linear acceleration profiles were used to identify hoof events, and each stride was divided into hoof-contact, break-over, initial-swing, terminal-swing, and total-swing segments. Kinematic variables were compared within and between limbs for each segment by use of mixed repeated-measures ANOVA. During the hoof-contact and terminal-swing segments, the hoof of the left (nonlame) forelimb had greater sagittal-plane orientation than did the hoof of the right (lame) forelimb. For the lame limb following lameness induction, the break-over duration and maximum cranial acceleration were increased from baseline. After perineural anesthesia, break-over duration for the lame limb returned to a value similar to that at baseline, and orientation of the hoof during the terminal-swing segment did not differ between the lame and nonlame limbs. Subclinical unilateral forelimb lameness resulted in significant alterations to hoof kinematics in horses that are walking, and the use of hoof kinematics may be beneficial for the detection of subclinical lameness in horses.

UDDER-HALVE-WISE COMPARATIVE PREVALENCE OF CLINICAL AND SUB-CLINICAL MASTITIS IN LACTATING GOATS WITH THEIR BACTERIAL PATHOGENS AND ANTIBIOTIC SENSITIVITY PATTERNS IN BANGLADESH

Goats are the major parts of subsidiary economy of the rural people in Bangladesh. Dairy animals including lactating goats are prone to the intramammary infection (IMI) and associated with a lot of economic impact on the farmers but the reports on caprine mastitis are very limited in inland literature. This study was undertaken to determine the udder-halve-wise comparative prevalence of clinical and sub-clinical caprine mastitis with their associated bacterial pathogens and antibiotic sensitivity patterns during the period from January to May 2010. The teat and udder of a lactating population of 1025 Black Bengal goats maintained under rural (village) condition in two different districts (Joypurhat and Mymensingh) of Bangladesh were physically examined, of which 54 (5.27%) goats had clinical mastitis which constituted as experimental animals for this study. Of the 54 selected goats, 59 (54.63%) udder-halves were affected with clinical mastitis whereas the remaining 49 (45.37%) udder-halves of the selected goats were found physically normal. Out of 59 udder-halves, 49 (90.74%) were unilaterally and 5 (9.26%) were bilaterally affected with clinical mastitis. The prevalence of clinical mastitis was found significantly (p < 0.01) higher in left udder-haves (H = 47; 79.66%) in comparison to the right (H = 12; 20.34%) udder-halves. Milk samples collected from all the 108 udder-halves were examined bacteriologically, of which 102 (94.44%) udder-halves had bacterial infection. No significant differences was observed on the status of bacterial pathogens between clinically (H = 55; 93.22%) and sub-clinically (H = 47; 95.92%) affected udder-halves, and between the single (CH = 45; 76.27% and SCH = 35; 71.43%) and mixed (CH = 10; 16.95% and SCH = 12; 24.49%) bacterial infections in both the clinical and sub-clinical mastitis udder-halves. The major bacterial pathogens isolated were Staphylococcus spp. which showed to be highest frequency (38.98%), followed by Escherichia coli (27.12%) and Bacillus spp. (10.17%) as a single clinical IMI whereas mixed IMI were also detected in both clinically and sub-clinically affected udder-halves. Antibiotic sensitivity results showed a relatively high level of resistance to ampicillin, amoxycillin and streptomycin, whereas gentamicin and ciprofloxacin were found to be the most effective drugs. These results indicate the high prevalence of sub-clinical mastitis in apparently normal quarters of lactating goats than those had clinical mastitis in other udder-halves, and therefore, there is a need for the prudent use of antibacterial in animal health and production through bacteriological and antibiogram studies in Bangladesh.DOI: http://dx.doi.org/10.3329/bjvm.v9i2.13456

Bayesian estimation of the diagnostic accuracy of a multiplex real-time PCR assay and bacteriological culture for 4 common bovine intramammary pathogens

Bacteriological culture (BC) is the traditional method for intramammary infection diagnosis but lacks sensitivity and is time consuming. Multiplex real-time PCR (mr-PCR) enables testing the presence of several bacteria and reduces diagnosis time. Our objective was to estimate bacterial species-specific sensitivity (Se) and specificity of both BC and mr-PCR tests for detecting bacteria in milk samples from clinical mastitis cases and from apparently normal quarters, using a Bayesian latent class model. Milk samples from 1,014 clinical mastitis cases and 1,495 samples from apparently normal quarters were analyzed by BC and mr-PCR. Two positive culture definitions were used: ≥1cfu/0.01mL and ≥10cfu/0.01mL of the specified bacteria. The mr-PCR was designed to simultaneously detect Staphylococcus aureus, Streptococcus uberis, Escherichia coli, and Streptococcus agalactiae. The priors used in our Bayesian model were weakly informative, with BC priors using the best available error data. Results were compared with those obtained using uniform priors for mr-PCR to test robustness. Weak and uniform priors gave about the same posterior distributions except for Strep. uberis from normal quarters and Strep. agalactiae. Multiplex real-time PCR Se on milk from clinical mastitis were lower than mr-PCR Se on milk from normal quarters. Multiplex real-time PCR Se was higher than BC on milk from normal quarters. Multiplex real-time PCR Se was generally lower than BC on milk from clinical mastitis and it varied by clinical severity. The estimate specificities of detection for all pathogens were ≥99%, regardless of sample type. The effect of milk sample preservation before testing was evaluated and may have been a factor that affected our observed results. A significant association was observed between sample age and mr-PCR results leading to reduced detection of E. coli and Strep. agalactiae in nonclinical samples. Differences in sample age between conduct of BC and of mr-PCR did not concur with any apparent differences between Se estimates of the 2 tests. Further work should be done to extend these results to other PCR-based tests for detecting bacterial species in milk samples, for which presented results could be used as prior parameter distributions. Limits of sample handling and storage and the potential existence of substances in clinical case samples that may interfere with PCR reactions also are worth further investigation.

Effect of mastitis on raw milk compositional quality.

In this study, we investigated the impact of mastitis infection on the quality of milk composition in small-scale dairy bovine herds. The purpose of this study was to find a milk quality somatic cell count (SCC) standard that could be used as an integral component of a control program. In all, 396 quarter milk samples from lactating cross-bred cows (Holstein & Zebu) were analyzed; 56% of these quarters were experiencing intramammary infection, with an overall mean SCC of 5.46 × 105 ± 2.30 × 104cells/ml. Infected quarters had significantly (p < 0.05) higher mean SCC levels (6.19 × 105± 4.40 × 104cells/ml) compared to healthy quarters (2.65 × 105 ± 2.40 × 104cells/ml). In high SCC milk and infected quarters, the concentrations of non-casein fractions, sodium, chloride, and free fatty acid were higher (p < 0.05), while the casein content, lactose, casein-to-total protein, potassium, and calcium were lower (p < 0.05) compared to normal quarters. These findings suggest a mean SCC threshold limit of 5.46 × 105 cells/ml for the region. It was concluded that the results could be used to propose a milk quality SCC standard that can be used as an integral component of a control program.

Relationship of blood and milk cell counts with mastitic pathogens in Murrah buffaloes

The present study was undertaken to see the effect of mastitic pathogens on the blood and milk counts of Murrah buffaloes. Milk and blood samples were collected from 9 mastitic Murrah buffaloes. The total leucocyte Counts (TLC) and Differential leucocyte counts (DLC in blood were within normal range and there was a non-significant change in blood counts irrespective of different mastitic pathogens. Normal milk quarter samples had significantly (P<0.01) less Somatic cell counts (SCC. Lymphocytes were significantly higher in normal milk samples, whereas infected samples had a significant increase (P<0.01) in milk neutrophils. S. aureus infected buffaloes had maximum milk SCC, followed by E. coli and S. agalactiae. Influx of neutrophils in the buffalo mammary gland was maximum for S. agalactiae, followed by E.cli and S. aureus. The study indicated that level of mastitis had no affect on blood counts but it influenced the milk SCC of normal quarters.

Glycaemic and insulinaemic response of Quarter Horses to concentrates high in fat and low in soluble carbohydrates

Quarter Horses are particularly susceptible to polysaccharide storage myopathy (PSSM). Nutritional therapy and possibly prophylaxis includes fat-supplemented diets whilst starch supply should be kept to a minimum. To investigate the glycaemic and insulinaemic response of clinically normal Quarter Horses to concentrates high in fat and low in starch. Twelve Quarter Horses were studied. The precondition for inclusion in the study population was that the horses had not shown clinical signs of myopathy. The Quarter Horses were fed according to a 4 x 4 Latin square design haylage plus isocaloric concentrates based on barley and oats as control (CO), sugar beet pulp, grass meal and soybean oil (SB), rice bran and grass meal (RB) and rice bran, grass meal, sugar beet pulp and soybean oil (CP), each over 2 weeks after 1 week of adaptation. At the end of each period, 1 kg of concentrate was fed and blood sampled 0, 30, 60, 90, 120, 180, 240, and 300 min post prandial (ppr.). Creatine kinase (CK; 0 min ppr. only), glucose and insulin were analysed. Glycaemic and insulinaemic index was calculated from each concentrates area under the curve (AUC) relative to CO. Rice bran containing concentrates were partially refused at the beginning of the trial periods. CK activity, and glucose and insulin patterns (ppr. mean, peak, AUC, index) were highest with CO (P<0.05). The correlation between glucose and insulin (P<0.001) ranged from r = 0.570 (CO) to r = 0.364 (RB). Basal CK was highly correlated (P<0.001) to the mean ppr. plasma glucose. Rice bran, sugar beet pulp, grass meal and soybean oil are suitable to include in concentrates that induce low glycaemic and insulinaemic response. Its acceptance seems to be a question of habituation. Although the mechanism is not completely understood, glucose patterns and basal CK activity are highly positively correlated. Both were affected by the type of concentrate used. Results support the suggestion that low-starch and high-fat feeding may be helpful not only in the nutrition of affected horses, but also to prevent future PSSM associated discomfort in particularly susceptible horses.

Visual appearance and CMT score of foremilk of individual quarters in relation to cell count of cows milked automatically

The objectives of the study were: to evaluate the interaction between visual appearance and California mastitis test (CMT) score of the foremilk in relation to the cell count of the milk; to evaluate the consequences of sorting milk according to these criteria; and to explore whether visual appearance and CMT score of foremilk depended on the time interval between milkings. Measuring somatic cell count (SCC) in composite milk only and discarding milk above certain thresholds will not ensure that milk from all cows with visually abnormal foremilk is withheld from delivery. Low thresholds of SCC will reduce the frequency of cows with abnormal milk but increase the discarding of milk from cows with visually normal foremilk. CMT score of foremilk differentiated better between cows with high and low SCC in composite milk than visual inspection of foremilk. CMT scores of foremilk decreased with increasing interval between milkings within cow, whereas the visual appearance was independent of the interval. We propose that visual appearance of the foremilk should be kept as a criterion for sorting milk at time of milking. For test purposes, the use of visual appearance of foremilk for differentiation between normal and abnormal milk has to be done on multiple milkings. Additionally, CMT scoring of foremilk improves correct classification of normal and abnormal quarters and especially when including data from the previous milking.

Skeletal muscle metabolic response to exercise in horses with 'tying-up' due to polysaccharide storage myopathy.

Polysaccharide storage myopathy (PSSM) is a distinct cause of exertional rhabdomyolysis in Quarter Horses that results in glycogen and abnormal polysaccharide accumulation. The purpose of this study was to determine if excessive glycogen storage in PSSM is due to a glycolytic defect that impairs utilisation of this substrate during exercise. Muscle biopsies, blood lactates and serum CK were obtained 1) at rest from 5 PSSM Quarter Horses, 4 normal Quarter Horses (QH controls) and 6 Thoroughbreds with recurrent exertional rhabdomyolysis (TB RER) and 2) after a maximal treadmill exercise test in PSSM and QH controls. In addition, 3 PSSM horses performed a submaximal exercise test. At rest, muscle glycogen concentrations were 2.4x and 1.9x higher in PSSM vs. QH controls or TB RER, respectively. Muscle lactates at rest were similar between PSSM and QH controls but significantly higher in PSSM vs. TB RER. Muscle glucose-6-phosphate concentrations were also higher in PSSM horses than controls combined. During maximal exercise, mean muscle glycogen concentrations declined 2.7x more and mean lactate increased 2x more in PSSM vs. QH controls; however, differences were not statistically significant. Blood lactate concentrations after maximal exercise did not reflect generally higher muscle lactate in PSSM vs. QH controls. No change in blood lactate concentrations occurred in PSSM horses with submaximal exercise. Serum CK activity increased significantly 4 h after maximal and submaximal exercise and was significantly higher in PSSM vs. QH controls. These results show that during maximal exercise, PSSM horses utilised muscle glycogen and produce lactic acid via a functional glycolytic pathway and that during submaximal exercise oxidative metabolism was unimpaired. The excessive glycogen storage and formation of abnormal polysaccharide in PSSM horses therefore appear to reflect increased glycogen synthesis rather than decreased utilisation. The specific subset of horses with exertional rhabdomyolysis due to PSSM would likely benefit clinically from a diet low in soluble carbohydrates like grain with fat added as well as gradually increasing daily exercise to reduce excessive glycogen accumulation and enhance utilisation.

Effect of high-intensity exercise on arterial blood gas tensions and upper airway and cardiac function in clinically normal Quarter Horses and horses heterozygous and homozygous for hyperkalemic periodic paralysis

Abstract Objective To determine the effect of exercise on arterial blood gas tensions and upper airway and cardiac function in clinically normal Quarter Horses and horses heterozygous and homozygous for hyperkalemic periodic paralysis (HYPP). Animals and Procedure 5 clinically normal Quarter Horses, and 5 heterozygous and 2 homozygous HYPP-affected horses were examined before, during, and after exercise on a high-speed treadmill. Arterial blood gas tensions, ECG, and echocardiogram were obtained prior to exercise. Upper airway endoscopy, collection of arterial blood samples, and continuous electrocardiography were performed during a high-intensity stepwise exercise test. An ECG was obtained within 1 minute after completion of the final step. Results None of the horses homozygous or heterozygous for HYPP had signs of weakness or muscle fasciculations before, during, or after exercise. Horses homozygous for HYPP had intermittent laryngospasm, dynamic pharyngeal collapse, and appreciable hypoxemia, hypercapnia, and ventricular premature contractions during exercise. Heterozygous and clinically normal horses did not have any abnormalities. Potassium concentration increased significantly above the baseline reference range during exercise in all groups of horses. Conclusions Horses homozygous for HYPP had laryngospasm and dynamic pharyngeal collapse associated with exercise, most likely secondary to increase in potassium concentration. Upper airway dysfunction is the most likely cause of hypoxemia and hypercapnia. Cardiac arrhythmias were most likely caused by a combination of hypoxemia and hyperkalemia. (Am J Vet Res 1998;59:615–618)

集団発生した緑膿菌性乳房炎について

When milk from each quarter was examined in lactating cows, Pseudomonas aeruginosa was detected from most of the quarters. It belonged to serotype II-B or III-G. It was also detected from the granulation tissue of mastitis quarters and the tissue of normal quarters of a killed cow. It belonged to the same serotypes as mentioned above.The isolated strains were sensitive to Colistin, Polymyxin B., Chloramphenicol, Oxytetracycline, and Tetracycline.

Glucose levels in normal and mastitic milk

Glucose levels in 188 quarter for milks from different cows were determined by an enzymic procedure. Mean glucose content was 0.22 mM (standard error +/- 0.009) and results ranged from 0.02-0.57 mM. Abnormal quarters had lower glucose levels (P less than 0.01) than normal quarters but variability within each classification was large. Glucose content was negatively correlated with both somatic cell count (r = 0.49) and N-acetyl-beta-D-glucosaminidase level (r = -0.61). Milk glucose was considered to be of limited value as a diagnostic test for mastitis.

Use of a conductivity meter for the detection of subclinical mastitis

The conductivity of milk from 164 cows in four herds was measured. There were significant differences between the normal and the mastitic quarters in each of the four herds. However, there was a marked difference in conductivity levels between the herds, the mean conductivity of the normal quarters in one herd being higher than that of the mastitic quarters in another herd. In a trial using a hand-held mastitis detector on 123 cows from three herds, 91 per cent of the 106 mastitic quarters were detected. However, 33 per cent of the 315 normal quarters also gave a positive reading.

Clinical pharmacokinetics of carbenicillin, carfecillin, ticarcillin and BL-P 1654 in dairy cows.

The minimal inhibitory concentrations (MIC) of carbenicillin, ticarcillin and BL-P 1654 for gram-negative udder pathogens were determined using the agar plate dilution method. The MIC of the drugs for 50% and 90% of the isolates examined ranged for Escherichia coli and Aerobacter spp. from 1.56 to 25 micrograms/ml, and for Klebsiella spp. and Pseudomonas spp. from 3.12 to 50 micrograms/ml. The Serratia spp. were relatively non-susceptible for the drugs studied (MIC greater than 50 micrograms/ml). Each drug was administered intravenously at 5 g and 15 g per cow to different groups of cows with normal and inflamed quarters of the udder. Distribution and elimination kinetic parameters calculated from serum drug level data were very similar to those of other beta-lactam antibiotics. Although drug concentrations in milk from inflamed quarters were higher than in milk from normal quarters, they were considerably below the MIC for the majority of gram-negative udder pathogens. The data suggest that parenteral treatment of gram-negative udder infections with carbenicillin, carfecillin, ticarcillin and BL-P 1654 at the dose levels used in the present study is unlikely to result in a bacteriological cure and would probably be clinically ineffective.

Pharmacokinetics of polymyxin B administered via the bovine mammary gland.

Polymyxin B was infused into normal, chronically inflamed, and acutely inflamed quarters of the mammary gland of lactating cows at dosages ranging between 1 and 2 million units (100-200 mg) per quarter. Samples of milk from treated and non-treated quarters, jugular venous blood, subcutaneous abdominal (mammary) venous blood, and urine were collected at intervals after treatment and were assayed using microbiological test methods for polymyxin B concentrations. The drug was not absorbed from normal and chronically inflamed quarters; more than 90% of the infused dose was recovered in milk within 24 h after treatment, and drug residues were detected up to the ninth milking. Drug concentrations in milk from acutely inflamed quarters were significantly lower than in milk from normal quarters; 55% of the infused dose was recovered in the milk within 24 h after treatment. The drug was detected in milk from non-treated quarters, in blood from the subcutaneous abdominal vein, and in the urine during 36-48 h after acutely inflamed quarters were infused with the drug. These data indicate that polymyxin B is well distributed throughout, and is absorbed to a significant degree into the systemic circulation from the acutely inflamed udder.

Electrical Conductivity of Milk for Detection of Mastitis

The potential value of electrical conductivity of milk as a screening test for subclinical mastitis was evaluated. Conductivity of foremilk and of post-milking strippings from 368 quarters of 92 cows was measured. Infection status of quarters was determined by bacteriological analysis of strict foremilk samples. Infections were classified as by primary or secondary pathogens, depending on the importance of the isolated organism as a mastitis pathogen. Somatic cells were counted on foremilk samples.Milk conductivity increased with infection. Conductivity of postmilking strippings was higher than that of foremilk in samples from quarters infected by primary pathogens. By thresholds which correctly classified at least 90% of normal quarters, accuracy of identifying primary pathogen infections by absolute conductivity was 62.8 and 96.2% with foremilk and postmilking strippings. Differential conductivity and combination of absolute and differential methods also were evaluated with the latter being the most effective. Number of quarters with elevated conductivity of postmilking strippings tended to be higher when somatic cell count was greater than 500,000/ml in both normal and infected groups. Conductivity of milk seems to hold promise as an indicator of subclinical mastitis.

Influence of Exercise and Stage of Lactation on the Milk Somatic Cell Response of Normal Quarters to Adrenocorticotrophin

Intramuscular injections of 200 IU of adrenocorticotrophin (ACTH) for 4 consecutive days failed to elicit detectable increases in the somatic cell content of milk from normal quarters despite large and sustained increases in the concentration of circulating leukocytes. Neither exercise nor stage of lactation had any detectable effect on the milk somatic cell response to ACTH. During midlactation (86 days in milk, 26 kg daily production) milk somatic cell counts for uninfected and Corynebacterium bovis-infected quarters averaged 28 and 77 × 103 cells/ml of milk, respectively, and during late lactation (302 days in milk, 5-kg daily production), 28 and 58 × 103 cells/ml of milk. The data suggest that neither ACTH nor late lactation will increase the concentration of milk somatic cells in quarters free from mastitis pathogens. These results support the use of the somatic cell concentration of milk as a criterion on which to assess milk quality.