Relationship between teat morphological traits and subclinical mastitis in Frieswal dairy cows

The present study was aimed to investigate the relationship between selected morphological traits of teat and subclinical mastitis (SCM) in Frieswal crossbred dairy cows. A total of 1040 quarters from 261 lactating cows were evaluated for teat shape (bottle/fleshy/collapsed/conical/normal/pencil and short), teat-end shape (dished/flat/funnel/pocketed/pointed and rounded), teat orientation (aligned/misaligned) and teat position (front and rear; left-sided and right-sided). Each udder quarter was screened with California Mastitis Test (CMT) for the purpose of defining quarter health status. Data were analysed using Chi-square test and multivariable logistic regression procedure. An overall prevalence of SCM (CMT positive) at quarter level was 30.6%. Most of the teats had normal or cylindrical shapes (48%), dished teat-ends (40.7%), and aligned (central or squared) in orientation (65%). At bivariable level, significant association of SCM with teat shape, teat position, teat orientation, parity, and stage of lactation was observed (P < 0.05 to P < 0.001). Teat-end shapes showed some association with SCM (P = 0.07). Results of multivariable analysis showed that pencil-shaped teats were least associated with SCM (P < 0.05) as compared to other teat shapes. Prevalence of SCM was also higher in rear teats (P = 0.015), misaligned teats (P = 0.01), and cows in second or higher parities (P < 0.01) and late stage of lactation (P < 0.001). The results of the present study indicate that selected morphological traits of teat are associated with SCM in Frieswal crossbred cows; therefore, selection towards desirable morphological traits could help reduce mastitis in this breed.     

Disease frequencies in dairy cows in Sweden. VI. Tramped teat

An epidemiologic study of 11 653 episodes of tramped teat is presented and various risk factors identified.Swedish Red and White Breed (SRB) had a lower incidence than Swedish Friesian Breed (SLB). The incidence increased to reach a peak in the fifth (SRB) and fourth (SLB) parities. The incidence was highest in the month of calving and decreased throughout the lactation period. Dystocia and parturient paresis increased the risk of tramped teat in the month of calving in SRB cows. In SLB cows, parturient paresis increased the risk. Cows of both breeds with a positive history of tramped teat had an increased risk of recurrence in subsequent lactations. Loose-housed cows had a lower incidence than tied cows. A positive report of tramped teat increased the risk of removal, irrespective of mastitis status.     

Relationship between California Mastitis Test score and ultrasonographic teat measurements in dairy cows

Objective The majority of published studies about mastitis are related to the control and prevention of mastitis, with particular emphasis on eliminating predisposition factors. The objective of the current study was to determine the role of teat morphology as an important factor in the aetiology of mastitis. Design Ultrasonographic measurements were taken from 190 teats from 100 dairy cows of different breeds. Procedure Mastitis in cows was diagnosed by the California Mastitis Test (CMT) and microbiological tests. The data were evaluated in the light of the clinical history of the animals. Results Main effects of breed on teat diameter at the position of the Furstenberg rosette (FTD) and teat cistern diameter (CD), that of age on FTD and overall teat diameter (OTD), and that of CMT score on CD and OTD were significant (P < 0.05, P < 0.01). Number of lactations, pregnancy, the lactation period and the udder lobe (rear, front) were not found to have a significant effect on any of the measurements. Results showed that CD was significantly smaller (1.44 ± 0.04 cm) (P < 0.01) in CMT‐positive udder lobes than that in CMT‐negative lobes. No difference was detected in canal length, CD, teat wall thickness, OTD or FTD between the CMT‐positive and ‐negative lobes. Conclusion The occurrence of mastitis could be related to specific ultrasonographic teat measurements (e.g. CD, OTD and FTD) and these may be important in the breeding of cows with a predisposition to mastitis, as well in the evaluation of in‐herd cows in terms of udder/teat deformities.     

Associations between teat injuries and fistula formation in lactating dairy cows treated with surgery

OBJECTIVE: To determine associations between rate of fistula formation and parity, lactation period, wound age, wound location, and shape of teat injuries in surgically treated teats in dairy cows. STUDY DESIGN: Prospective clinical study. ANIMALS: 106 lactating dairy cows with teat lacerations. PROCEDURES: Lacerations were classified via shape, location, and age. Associations between potential risk factors and fistula formation were analyzed. Seasonal distribution, type of injured teat, parity, and days in lactation were determined. RESULTS:Cows with teat injury in their first and second parity had 4.1 times the odds of fistula formation, compared with cows with parity >or= 3.Teats sutured within 48 to 72 hours of injury had 8.3 times the odds of fistula formation, compared with teats sutured within the first 24 hours. Cows in early lactation stage (first 60 days of lactation) were more susceptible to teat injuries. Occurrence of teat injury was greater at the third, fourth, and fifth parity. CONCLUSIONS AND CLINICAL RELEVANCE: Season, parity, and lactation period were associated with prevalence of teat injury in lactating dairy cows in a range system. Neither the type of suture material used nor the suturing technique was associated with effects on healing of the operated full-thickness teat wounds. Factors such as parity and age of the wound can be associated with delay in the healing process, which may result in fistula formation.     

Comparison of media to isolate Staphylococcus aureus from teat skin and milking unit liners.

Four procedures were compared for isolation of Staphylococcus aureus from swabbing solutions of teat skin and milking unit liners from commercial dairies. In 2 procedures, 0.1 ml of swabbing solutions were added to either 5 ml Vogel-Johnson or Baird Parker broth media and enriched at 37 degrees C, 4 h. Following enrichment, 0.1 ml culture was transferred to modified Baird-Parker agar and incubated at 37 degrees C, 48 h. In the other 2 procedures, 0.1 ml of swabbing solution was directly placed on either blood or modified Baird-Parker agar plates and incubated at 37 degrees C 48 h. Combining results from all methods, Staphylococcus aureus were isolated from 72 of 913 (7.9%) skin samples, and 34 of 268 liners (12.6%). On average, 43.1% (31/72) of the S. aureus isolates were found by the enrichment in liquid Vogel-Johnson procedure. The average isolation percentage for other methods ranged from 19.4% to 25.0%. Isolation of S. aureus from milking unit liner or teat skin swabbing solutions was approximately twice as likely after enrichment in Vogel-Johnson liquid media as opposed to other methods of isolation. This indicates that enrichment in Vogel-Johnson liquid media improved recovery of S. aureus from swabbing solutions.     

Ultrasonography of the teat canal in cows and sheep

When the isolated teat of a cow was examined with an 8.5 MHz linear array transducer in a vertical plane, the teat canal appeared as a thin, white line, bordered on each side by parallel, thick, grey-black bands. In a horizontal plane a comparable image was obtained. In a sheep, images of comparable quality were obtained with a 12 MHz transducer. Histological studies of the tissues whose removal led to the disappearance of this characteristic ultrasonographic appearance showed that it was associated with the stratified keratinised squamous epithelium with distinct papillae. The content of keratin in the stratum corneum was apparently responsible for the bright zone; the stratum lucidum was not visible, and the surrounding dark, less echoic area was associated with the stratum granulosum. Doppler echography in live animals confirmed this designation. The outer layers of the teat wall were more echogenic.     

Endoscopic, pathologic-anatomic and histologic findings in the bovine teat. 1. Changes in the area of the teat cistern in slaughtered cows

In the present study 795 teats of slaughtered cows were examined endoscopically. Teats which showed lesions were examined histologically. Abnormalities were detected endoscopically in 37 teats. In five cases red discolorations were observed. Histologically these alterations proved to be fresh bleedings within the fibromuscular layer of the teat cistern. Thirteen teats showed yellowish discolorations of the cistern surface. Three of these cases could not be cleared up histologically. In the other cases moderate or severe blood pigment deposition (n = 10) or severe fibrosis (n = 3) of the fibromuscular layer were found. Neither fresh bleeding nor severe blood pigment deposition was found in teats with normal coloured epithelium of the cistern. Cistern surface was smooth in 18 cases, whereas in 19 cases nodules were found. Histologically all nodules consisted of fibrovascular tissue ("granulation tissue") covered with cisternal epithelium. Detailed histological examinations, however, revealed considerable morphological variations regarding the overlying epithelium, the extent and kind of cellular infiltration, the extent of angioplasia and fibroplasia as well as fresh bleedings or deposition of blood pigment in the underlying fibrovascular tissue in some cases. It was concluded, that teat endoscopy enables a differentiation between fresh and old bleedings according to the coloration of the cisternal surface. Nodular proliferations of the cistern surface generally consists of fibrovascular ("granulation") tissue. Further histological details, however, and thus possible information about the pathogenesis of the lesions cannot be assessed endoscopically.     

Occurrence and radiological studies of different teat changes in milk cows

The aim of this study was to investigate the incidence of different teat lesions in cows that cause obstruction of milk flow. 18,400 teats were palpated in Konya slaughterhouse. From these 1000 hard milking or obstructed teats were found (5.4%). Based on the radiographical results, distal 1/3, proximal 2/3, complete teat lesions and congenital obstructions were found in 70.1, 16.6 and 0.7% respectively.     

Relationship between penetrability of the papillary duct (teat) and phagocytic capability in lactating dairy cows

To determine whether there is a reciprocal relationship between penetrability of the papillary duct of the teat (streak canal) and phagocytic capability, 3 cows with highly penetrable papillary ducts and 3 with ducts highly resistant against penetration were identified, using a penetrability assay. Leukocytes harvested from milk from these cows were tested for their capability to phagocytose Staphylococcus aureus. Phagocytic capability was found to be independent of the ability of microorganisms to gain access to the interior of the mammary gland.     

Surgical treatment of accessory teat and gland cistern complexes in three cows

The diagnosis of accessory teat and gland cistern complexes, a technique used for surgical removal of the fistulae, a method for connecting 2 complexes at the level of the teat cisterns, and complications observed after the procedures are described for 3 cows. All cows produced greater than 8,000 kg of milk during the lactation in which surgery was performed. The surgical procedure may be economically justified in cows that are high milk producers or have the genetic potential for high milk production.     

Simulation study of teat score in first-parity Gelbvieh cows: parameter estimation

Teat scores from 9,598 first-parity Gelbvieh cows were used to investigate the adequacy of grouping approaches to decrease score misclassifications or inconsistencies as well as to simplify the data collection process. The procedure was tested using simulated data and then validated using teat score records of Gelbvieh cattle. First-parity cows were considered to be 4 yr of age or younger at first calving, did not have multiple records within 280 d, and were at least 50% Gelbvieh. Producers scored cows within 24 h of parturition. Teat score, a subjective measure of teat size, ranged from 0 (very large) to 50 (very small). A linear mixed model that included herd-year, month of calving, and age at calving as systematic effects; regression on the percentage of Gelbvieh; and additive breeding values (BV) and residual as random effects was used to generate the data. Simulated data were analyzed using one of three scoring methods: all values (S50), 10 classes (S10), and five classes (S5). The 10 classes were formed by subdividing every five scores into a single class starting at score zero. Similarly, the five classes were formed by combining every 10 scores into one class. The average Pearson correlations, based on five replicates, between the true and estimated BV (systematic effects) were 0.36 (0.85), 0.35 (0.89), and 0.32 (0.87) using S50, S10, and S5, respectively. Average correlations between estimated BV (systematic effects) were 0.97 (0.95), 0.89 (0.92), and 0.92 (0.97) based on S50 and S10, S50 and S5, and S10 and S5, respectively. Field data were used to validate the simulation procedure. The field data were categorized into 10 classes (F10) and five classes (F5) as described for the simulated data. Pearson correlations between estimated BV (systematic effects) were 0.99 (0.93), 0.93 (0.88), and 0.93 (0.96), based on F50 with F10, F50 with F5, and F10 with F5, respectively. The extremely high correlations between predicted BV based on S50, S10, S5, F50, F10, with F5 suggest that a simplified score classification method could be adopted without compromising the expected genetic progress for the trait under consideration. Furthermore, the difference in corresponding Pearson correlations across the field and simulated data might suggest the presence of some inconsistencies or misclassifications of the actual scoring system.     

Relationship between morphological characteristics of the teat duct and prevalence of intramammary infections with Streptococcus agalactiae in dairy cows

The objective of the study was to determine the relationship between morphological findings of the surface of teat duct particularly the level of ceratosis and the prevalence of intramammary infections (IMI). The study was conducted on a commercial dairy herd housing about 3000 lactating dairy cows. We examined 891 quarters in the middle of lactation. Duplicate samples of quarter foremilk were collected monthly. The bacteriological status of quarters was determined according to the recommendations of IDF. At the same time teats were evaluated by clinical examinations. The appearance of teat skin lesions and the status of the teat duct especially the existence of hyperceratosis (HC) was documented. Four classes of teat duct hyperceratosis were defined: without, slight, medium and severe HC. The rate of IMI in different classes of hyperceratosis of teat duct was compared by Chi-square analysis. Prevalences of intramammary infections were determined three times (P1, P2 and P3) during the study period. Prevalence of infection was high for S. aureus (P1: 5.6% vs. P2: 4.5% vs. P3: 4.3%), Sc. agalactiae (P1: 2.7% vs. P2: 2.6% vs. P3: 2.8%) and CNS (P1: 10.7% vs. P2: 8.8% vs. P3: 9.6%). Furthermore we detected IMI caused by other streptococci, yeast, E. coli and mixed infections. A positive correlation between status of HC and prevalence of IMI for Sc. agalactiae was found. At the second and third sampling time the rate of intramammary infection with Sc. agalactiae in quarters with medium HC (P2: 9.21% and P3: 13.73%) differed significantly (p < 0.05) compared to groups without (P2: 1.56% and P3: 1.91%) and slight hyperceratosis (P2: 2.33% and P3: 2.56%). The results of our study indicate a correlation between morphology of teat duct surface, especially regarding to Sc. agalactiae. On one hand HC can cause high intramammary infection rate with Sc. agalactiae. On the other hand it is possible that HC is the consequence of a quarter infection with Sc. agalactiae. Further research is required.