Teat Wall Research Articles

Different Types of Milk Flow Curves and Factors Affecting Milkability in Buffalo Species

Buffaloes are characterized by longer teats and teat canals and stronger muscular resistance of the teat wall than cattle; it is necessary to have a high vacuum level to open the teat canal and begin milk ejection. In buffalo milking management, milk yield, and flow profiles are essential parameters to record and evaluate. The milking machine is a critical point, and the characteristics of the milking vacuum and the pulsation rate are closely related to milk flow observations. In Italy, the most used vacuum levels are 44-46 kPa (range 40-53 kPa). The data on the milkability traits of the Mediterranean Italian breed made it possible to classify eight different types of milk flow curves due to anatomical, physiological, and management differences. This study aims to evaluate the main factors influencing milkability in dairy buffaloes. The results suggest the detachment of the milking cluster to reduce the decreasing and blind phases with the following advantages: reduction of the total milking time and consequently of the worker's time, improvement of the farmer's profitability and milk quality through decreasing the incidence of mastitis. Milk ability is influenced by physiological, sanitary, management, and genetic factors. In Mediterranean Italian buffaloes milked with the Automatic Milking System (AMS), a considerable variation in milk ejection and, consequently, in the milk flow curve was found compared to the conventional one, with better pre-stimulation, independent milk ejection for each teat, optimal milking of all quarters. In conclusion, continuous milkability monitoring will help optimize milking practices by reducing labor time and increasing farmers’ income through better milk quality. In addition, the identification of buffaloes with desirable types of milk flow curves could be helpful for buffalo breeders’ associations to address farmer management and to define potential new breeding objectives.

Ultrasonographic, endoscopic and radiographic examinations of the dromedary mammary glands and teats

The aim of the present study was to examine the mammary gland of dromedary camels using ultrasonography, endoscopy and radiography. These techniques are easy to perform in the field and feasible to diagnose pathological conditions of the mammary gland. Udders of 49 slaughtered and 26 adult dromedary camels submitted for necropsy were used for the examinations. Additionally, 11 lactating female dromedary camels were selected for the ultrasonographic udder examination. The transition from the milk ducts into the udder cistern, the teat cistern and the teat canals were examined in individual udders. Teat cistern length, teat end width, teat wall thickness, teat cistern width and middle cistern wall thickness were measured using ultrasonography. The measurements resulted in mean values of the teat cistern length of 37.3 mm, the teat end width of 2.0 mm, the teat wall thickness of 4.4 mm, the teat cistern width of 8.2 mm and the cistern wall thickness of 3.5 mm. The teat wall was differentiated into three layers, a hyperechoic outer layer, a hypoechoic middle layer and a hyperechoic inner layer. The mid cistern wall was hyperechoic. Endoscopic examination is an easy to perform and practicable method for examining the inner structures of the teats of dead animals; however, the feasibility has not been shown in lactating animals yet. Ring-like folds were present in the teat cistern, which protruded horizontally into the lumen. It was also possible to visualize the branchlike transition of the teat cistern into the larger milk ducts. Radiographic examination using barium sulfate contrast medium showed that the teat cistern ends in a network of initially wide but branching and narrowing milk ducts. The two teat canals and cisterns are completely independent of each other and there is no communication between the glandular tissue of the two canals and cisterns.

Assessing teat canal morphology in the dry period and during lactation by high-resolution ultrasound.

Our objectives were to quantify the dimensions of a fully 'closed' teat canal in dry cows and to describe recovery of the teat canal between milkings in lactating cows to assess whether and when full closure is attained, since this is an important determinant of udder health. Using an ultrasound scanner, teat canal length and diameter (proximal, midpoint and distal), teat cistern width, teat end width, whole teat width and teat wall thickness in 77 dry and 39 lactating dairy cows were measured. The dry cows represented a cross section of the dry population, with days since dry off ranging from 0 to 69 (median: 27). Data from lactating cows were recorded just before milking, and every 3 h post-milking. To control for location a cross-over (parlour vs. barn) study design was used. In dry cows, teat canal length and diameter did not vary by quarter or days since dry off, but multiparous cows had significantly wider teat canals than primiparous cows. The dry cow measurements can be used as baseline for dimensions for closed teats. In lactating cows, all teat dimensions except teat end width changed significantly during the 12-h milking cycle. Location (parlour vs. barn) did not affect the measurements, except teat end width and teat wall thickness. Teat canal length increased after milking and returned to pre-milking values by 9 h. Proximal and midpoint teat canal diameters decreased slightly just after milking and then progressively increased to above the pre-milking values by 9 h. Distal teat canal diameter increased after milking, partially contracting by 9 h. We found that during the dry period the teat canal is in a steady state, but its diameter is not zero, while during the lactation, the teat canal is in a near constant state of remodelling.

Teat morphology across five buffalo breeds: a multi-country collaborative study.

The buffalo (Bubalus bubalis) is a species of worldwide importance, raised to produce milk, meat, and hides, and often used as a working animal in rural contexts with low access to hi-tech solutions. In the present study, 100 lactating buffaloes (50 primiparous and 50 pluriparous) of five popular breeds were recruited to characterize and compare teat morphology. In particular, the focus was put on the Nili Ravi, Mediterranean, Egyptian, Bulgarian Murrah, and Azeri buffaloes raised in Pakistan, Italy, Egypt, Bulgaria, and Iran, respectively. In all countries, a longitudinal cross-section ultrasound was obtained before the milking to measure teat parameters at individual level: overall, teat canal length (TCL) averaged 24.13mm, teat diameter (TD) 30.46mm, cisternal diameter (CD) 17.80mm, and teat wall (TW) 7.12mm. The most variable trait across breeds was TCL which was positively correlated with CD and TD and negatively with TW, regardless of the teat position (front/rear or left/right). A strong negative correlation was found between TW and CD (- 0.43). The analysis of variance revealed that the fixed effect of breed significantly affected all the traits except TD. In fact, Bulgarian Murrah, Azeri, and Egyptian buffaloes presented the greatest estimate of TCL, whereas NR the smallest (14.70mm). The TW was maximum in Nili Ravi, Egyptian, and Mediterranean buffaloes, with estimates equal to 8.19, 7.59, and 8.74mm, respectively. Nili Ravi also showed the greatest TL (82.39mm). In terms of CD, the lowest least square mean was that of Mediterranean buffaloes (12.14mm). Primiparous and pluriparous buffaloes differed in terms of TD, TW, and TL, with older animals presenting the highest least square mean. In terms of position, instead, significant differences were observed for TD, CD, and TL when comparing front and rear teats, as left and right teats did not differ. Teat anatomy includes a set of heritable morphological features and is therefore breed-dependent. Differences presented in this study could be attributed to the divergent breeding objective and selective pressure across the five breeds; e.g., in some cases such as Mediterranean buffalo, selection for decades was oriented to improve milk production and milkability and achieve optimal conformation for mechanical milking. A better understanding of the mammary gland anatomical descriptors can be informative of the history of a breed and could provide useful insights to guide possible selection.

Biometric and ultrasonographic evaluation on mammary gland of goat

Gross and ultrasonographic studies were conducted on the mammary gland of goat (n=18 for each study) during pre-pubertal, lactating and non-lactating stages. Mammary gland was located into the inguinal region and divided into two halves by mammary groove which was prominent during lactation stage. Each halve had separate glandular body and conical teat divisible into tip, mid and base regions. The mammary gland contained numerous lactiferous ducts which opened into the gland sinus that continued distally as teat sinus and teat canal. The gland sinus and teat sinus were separated from each other by annular folds, which were more prominent in lactating animals. At the junction of teat sinus and teat canal, small mucosal elevation was observed as Furstenberg’s rosette. Teat wall was lined by skin, teat internal mucosal layer and teat sinus from outside to inside. Ultrasonographic observations showed that the lactating mammary gland contained an echogenic structure of variable size indicating gland sinus, lactiferous ducts, blood vessels, glandular parenchyma, while the homogenous echogenic component depicting more connective tissue stroma in non-lactating and pre-pubertal goat. The teat wall was made up of innermost hyperechogenic layer (teat mucosa), middle hypoechogenic (fibromuscular) layer and mild hyperechogenic teat skin. Teat sinus was anechogenic, however teat canal was demarcated by hyperechogenic streak. Biometrical and ultrasonographic observations were recorded on teat canal length, maximum diameter of teat, maximum teat wall thickness. Present study showed that there was no significant difference in biometric and ultrasonographic measurements of goat teat. Therefore, it may be concluded that the gross and ultrasonographic observations may be used to diagnose any abnormality in the udder during clinical examination.

The mouthpiece chamber vacuum pattern indicates the cessation of milk flow and suits as an indicator to reduce teat end vacuum at a quarter level

We investigated the suitability of the quarter mouthpiece chamber vacuum (MPCV) as an indicator for cessation of quarter milk flow to potentially adjust the teat end vacuum at a quarter level. We tested the hypothesis that a MPCV increase is a clear indicator of quarter milk flow cessation. In addition, we tested if a quarter-individual vacuum reduction at MPCV increase reduces the mechanical effect on the teat. Ten dairy cows were milked twice daily with a quarter-specific vacuum supply with continuously high (51 kPa; TRT51) or low vacuum setting (41 kPa; TRT41), or high vacuum setting combined with a quarter-specific vacuum reduction by 10 kPa immediately after the quarter-specific MPCV increase (TRT51/41). Whole udder milk flow was continuously recorded. Each treatment was repeated at 4 subsequent milkings. The high vacuum settings (TRT51; TRT51/41) reached higher values in peak flow rate and average milk flow and consequently shorter machine-on time. The time from start of milking until the steep increase of the MPCV was shorter in front than rear quarters, and hence the time from start of MPCV increase until end of milking was longer in front than rear teats. Teat condition of the right front teats was measured for teat wall diameter by ultrasound and teat tissue thickness by cutimeter at 5 and 20 min after each experimental milking. The teat measurements were taken at the teat tip (distal barrel) and 2 cm above the teat tip (proximal barrel). The proximal teat wall diameter tended to be higher in TRT51 than in TRT41, both 5 and 20 min after milking. The distal teat wall diameter at 5 min was greater in TRT51 than in TRT41. In TRT51/41 the teat wall diameter at both locations was intermediate, not significantly different from either TRT51 or TRT41. The distal teat tissue thickness was greater in TRT51 than in TRT41, and tended to be greater in TRT51/41 than in TRT41 at 5 min. The proximal teat tissue thickness at 5 min was higher in TRT51 and TRT51/41 than in TRT41. The teat tissue thickness decreased from 5 to 20 min only in the proximal barrel. The quarter-individual MPCV increase appears to be a suitable indicator of the cessation of milk flow. The lack of a significant reduction of mechanical effect on the teat by a reduced vacuum of 41 kPa indicates that the vacuum level chosen may be still too high under conditions of a separate vacuum supply for each quarter, which prevents a vacuum drop caused by the whole udder milk flow.

Increased teat wall thickness in response to machine milking

Transiently increased teat wall thickness in response to machine milking has been documented by various methods, including ultrasound. However, correlative ultrasonography and histology to detect the origin of this phenomenon is lacking. The first goal of the present study was to evaluate and compare milking-related changes of the teat tissue in 2 breeds of dairy cows (11 Simmental and 3 Holstein) using B-mode ultrasonography. Additionally, the observed changes were compared with ultrasonographic findings in a Holstein cow with periparturient udder edema. Finally, corresponding histological sections of the Simmental teats were analyzed and compared with those from a lactating nonmilked Angus cow. We hypothesized that the mechanical load of both stretching by the vacuum during phases of open teat cup liner and compression by the closed liner during machine milking results in a transient congestion of blood vessels in the teat wall. The barrel of 1 front teat of each cow was scanned immediately before and after machine milking (system vacuum: 42 kPa; pulsation rate: 60 cycles/min; pulsation ratio: 65:35). Shortly after milking (33 ± 6 min), the Simmentals were slaughtered, and their scanned teat was immediately removed and processed for investigation by light microscopy. Ultrasonography after milking revealed anechoic tubular structures mainly in the inner half of the teat wall. Histological examination revealed these structures to be thick-walled veins. The left front and hind teats of the nonmilked lactating cow, collected and prepared identically to those from the Simmental cows, showed the same histological features. Ultrasonographic measurements showed that the diameter of these veins significantly increased after milking compared with matching images before milking. This effect was most pronounced in the Holstein cows. Similarly, these veins were very prominent in the periparturient cow. However, neither the milked cows, including the periparturient cow, nor the lactating nonmilked cow provided any evidence of edematous extravasation on ultrasonography or histology. These findings corroborated our hypothesis that the increase in size of thick-walled veins in the teat tissue is the main reason for the thickening of the teat walls in response to machine milking.

The Effect of Pre-milking Stimulation on Teat Morphological Parameters and Milk Traits in the Italian Water Buffalo.

Water buffaloes (Bubalus bubalis) are very sensitive to environmental stimulus before and during milking, and this explains why disrupted milk ejections due to blood oxytocin level instability are frequent in this species. According to the literature, the manual stimulation (MS) of teats before milking promotes oxytocin release and allows milk ejection to start within 2–3 min. However, the pre-milking stimulation of teats is not always part of the milking routine in Italian buffalo farms; moreover, buffaloes with unstable milk let-down are sometimes treated with exogenous oxytocin (OX). Different types of pre-milking stimulation can impact differently on the mammary gland epithelium and structures and, therefore, on milk yield. In this study, we observed the changes in teat morphological traits before and after the application of three types of stimuli, i.e., no manual stimulation (NS), MS, and OX, in buffaloes reared in an Italian dairy farm. In particular, measurements were available for 23 and 21 buffaloes for front and rear teats, respectively. Subsequently, the effect of the pre-milking stimulation type was estimated on teat morphological characteristics and on milk traits recorded after the application of stimuli. The results showed that the teat canal length was shorter (P < 0.05) after stimulation in the case of MS and OX compared to NS. Cistern diameter was overall greater for MS and lower for OX. On the contrary, teat wall thickness was greater and lower for OX and MS, respectively. Milk yield and quality (fat, protein, and somatic cell score) were similar across the three types of pre-milking stimulation. In perspective, the impact of these types of pre-milking stimulation should be evaluated on a large scale, and the focus might be put on mammary gland epithelium integrity, mastitis incidence, and other udder health indicators in milk, e.g., electrical conductivity, differential somatic cell count, lactose content, and sodium and chloride concentration.

Different vacuum levels, vacuum reduction during low milk flow, and different cluster detachment levels affect milking performance and teat condition in dairy cows

Traditionally, machine milking is performed at a constant vacuum supply. The system vacuum has to be set high enough to allow a sufficiently high vacuum at the teat end, despite the inevitable vacuum drop caused by milk flow. This leads to an increased vacuum load on the teat, especially when milk flow ceases at the end of milking. We tested the hypothesis that a milk flow-controlled adaptation of vacuum settings during milking allows even higher vacuum levels than are usually recommended during the period of high milk flow if the vacuum is reduced during low milk flow. Combined with a high cluster detachment flow rate level, increased milking performance is expected without an increased effect on teat tissue. Ten Holstein dairy cows were milked with a bucket milker with the claw vacuum adjusted in the absence of milk flow at a regular (43 kPa) and high (48 kPa) claw vacuum, with and without vacuum reduction during low milk flow (<2 kg/min), and combined with different cluster detachment levels (0.2, 0.6, and 1 kg/min). Each treatment was applied in each cow during 4 subsequent milkings in a randomized crossover design. Both claw vacuum and milk flow were continuously recorded throughout milking. Teat tissue thickness was measured using a cutimeter and teat wall diameter was measured by B-mode ultrasonography at 5 min after the end of milking. Milk yield was not affected by either vacuum settings or detachment levels. Machine-on time in treatments with vacuum reduction was shorter at high than at low vacuum and decreased with increasing detachment levels. Average milk flow was higher at high than at low vacuum and reached highest values in milkings without vacuum reduction at both vacuum levels. The average milk flow was higher at a cluster detachment of 1 kg/min than at 0.2 kg/min. However, both teat tissue thickness and (as a tendency) teat wall diameter at 5 min after cluster detachment were higher in milkings at high vacuum without vacuum reduction compared with all other treatments. In conclusion, high claw vacuum up to 48 kPa increases milking performance because of higher milk flow and reduced machine-on time. Negative effects of high vacuum on teat tissue are prevented by reducing vacuum during low milk flow (<2 kg/min) at the start and end of milking. Additionally, using a high cluster detachment level reduces machine-on time without a loss of harvested milk.

Teat characteristics in relation to animal temperament during milking in buffaloes, and comparison of buffalo and cow teat morphology

This study aimed to examine the teat characteristics in relation to the animal temperament during milking in the Anatolian buffaloes using ultrasonographic, histomorphological and immunohistochemical methods. The teat canal length (TCL), teat wall thickness (TWT), teat cisternal diameter (TCD), teat diameter (TD), teat length (TL), and teat circumference (TC) values in docile (n=5) and nervous (n=7) buffaloes were measured at the 0th,3rd and 6th minute of stimulation. In additional experiments, comparative histomorphology and immunohistochemical examinations of buffalo (n=7) and cow teats (n=8) were performed. It was determined that post-stimulation mean TCL values were significantly higher in nervous buffaloes than those of teats in docile buffaloes (p<.05). A significant positive correlation between TCD and TD, TL and TC in both docile and nervous buffaloes was noted (p<.05). Unlike nervous buffaloes where only 3/14 teat canals were open by 3rd minute of milking stimulation, almost all (9/10) teat canals were observed opened in docile buffaloes. There were fewer muscle but more collagen bundles in buffalo teats compared with cow teats. It seems that temperament of animal during milking effects the milking efficiency, and in nervous buffaloes, probably the stimulation alone may not be sufficient for opening of the teat canal and hence achieve complete milking.

Short communication: Teat wall diameter and teat tissue thickness in dairy cows are affected by intramammary pressure and by the mechanical forces of machine milking

The objective of this study was to validate and apply 2 different methods to record changes in teat tissue related to machine milking. Teat wall diameter was measured via B-mode ultrasound cross sectioning with a 7.5-MHz linear probe. Teat tissue thickness was measured using a cutimeter (spring-loaded caliper, spring constant 6.5 N/cm, 0.5 N at closed jaws). Both methods were applied at the teat barrel, 2 cm above the teat tip. In experiment 1, 24 teats from freshly slaughtered cows were used to perform ultrasound imaging (12 teats) or cutimeter measurements (12 teats) while the teat cisterns were filled with water to increase the intracisternal pressure from 0 to 30 kPa in steps of 1 kPa. Teat tissue thickness did not change at an intracisternal pressure from 0 to 10 kPa but increased with intracisternal pressure at levels >10 kPa. In contrast, teat wall diameter decreased with intracisternal pressure between 0 and 7 kPa but did not significantly change at a pressure ≥7 kPa up to 30 kPa. Significant Pearson correlation coefficients between intracisternal pressure and teat wall diameter were observed from 0 to 7 kPa (r = -0.38), and between intracisternal pressure and teat tissue thickness from 10 to 30 kPa (r = 0.45). In experiment 2, ultrasound and cutimeter measurements were performed in 12 lactating Holstein cows. Measurements before and during milking, immediately after cluster removal, with normal milking or with a 5-min overmilking, were performed and continued at 5-min intervals for 60 min and at 10-min intervals until 120 min. Additionally, with the 5-min overmilking treatment, measurements were continued at 60-min intervals up to 10 h after milking. Teat wall diameter decreased in response to milk ejection, followed by a continuous increase during the course of milking, with highest values after 5 min overmilking. Teat tissue thickness did not change during milking but was significantly increased after overmilking. Teat wall diameter and teat tissue thickness recovered to premilking levels within 35 min after normal milking and within 60 min after overmilking. Until 10 h after overmilking, the teat wall diameter decreased steadily, whereas teat tissue thickness was unfluctuating. In the physiologically relevant range of intramammary pressure, ultrasound measurements of the teat wall were affected by both intramammary pressure and mechanical forces, whereas cutimeter measurements were not affected by the intramammary pressure.

Ultrasonographic Evaluation of Teat Structure and Detection of Prominent Annular Folds in Brazilian Dairy Buffaloes

Udder and teat characteristics differ between buffaloes (Bubalus bubalis) and cattle (Bos taurus) and the differences are important in relation machine milk ability. Dairy buffalo milk out more slowly and are more difficult to milk than dairy cows, especially when milking machines are used. The goal of this study was to determine the ultrasonographic characteristics of udder and teat morphology in dairy buffaloes in Brazil, a country with a relatively recent history of buffalo farming. External assessment of the udder type and ultrasonography of the teat were done in 63 purebred Murrah and Mediterranian ´ Murrah dairy buffalo cows on three farms with different management systems. Udder types differed among farms; the rear-heavy udder type was most prevalent on two farms and the ball-shaped type occurred frequently on the third farm. Ultrasonographic measurements of the teat were made on one farm and showed correlations between the width of the teat tip and teat canal length, between the width of the teat tip and teat wall thickness and between the width of the teat tip and teat length. During the ultrasonographic examination of the teat, hyperechogenic membrane-like structures in the region of the annular folds, referred to as prominent annular folds (pAFs), were detected in at least one teat in 98 % of all buffaloes. These folds caused narrowing of the lumen between the teat cistern and gland cistern, but their physiological function and relevance concerning machine milk ability remain unclear. Further studies are needed to evaluate the effect of prominent annular folds on milk flow characteristics during mechanical milking in dairy buffaloes.

An observational study investigating the association of ultrasonographically assessed machine milking-induced changes in teat condition and teat-end shape in dairy cows

Mechanical forces during machine milking induce changes in teat condition which can be differentiated into short-term and long-term changes. Machine milking-induced short-term changes in teat condition (STC) are defined as tissue responses to a single milking and have been associated with the risk of new intramammary infection. Albeit, their association with teat characteristics, such as teat-end shape, has not been investigated by rigorous methods. The primary objective was to determine the association of STC, as measured by ultrasonography, with teat-end shape. The second objective was to describe possible differences in the recovery time of teat tissue after machine milking among teats with different teat-end shapes. Holstein cows (n=128) were enrolled in an observational study, housed in free-stall pens with sand bedding and milked three times a day. Ultrasonography of the left front and right hind teat was performed after teat preparation before milking (t−1), immediately after milking (t0) and 1, 3, 5 and 7 h after milking (t1, t3, t5, t7). The teat tissue parameters measured from ultrasound scans were teat canal length, teat-end diameter, teat-end diameter at the midpoint between the distal and proximal end of the teat canal, teat wall thickness, and teat cistern width. Teat-end shape was assessed visually and classified into three categories: pointed, flat and round. Multivariable linear regression analyses showed differences in the relative change of teat tissue parameters (compared with t−1) at t0 among teats with different teat-end shapes, with most parameters showing the largest change for round teats. The premilking values were reached (recovery time) after 7 h in teats with a pointed teat-end shape, whereas recovery time was greater than 7 h in teats with flat and round teat-end shapes. Under the same liner and milking machine conditions, teats with a round teat-end shape had the most severe short-term changes. The results of this observational study indicated that teat-end shape may be one of the factors that contribute to the severity of STC.

478 Ultrasound teat wall diameter and cutimeter teat tissue thickness before, during, and after machine milking.

478 Ultrasound teat wall diameter and cutimeter teat tissue thickness before, during, and after machine milking.

Evaluation of inner teat morphology by using high-resolution ultrasound: Changes due to milking and establishment of measurement traits of the distal teat canal

The teat canal is important in the defense against invading pathogens, but its functional features can be impeded by the milking process. The objective of our study was to compare teat morphology before and after a standard milking procedure using high-resolution ultrasonography. Tissue changes were determined by measuring inner traits of teat morphology: teat width, teat end width, teat cistern width, diameter of the lower and upper teat wall, teat canal length, and teat canal diameter. Additionally, 3 traits describing the distal teat canal and its external orifice were established: diameter of the distal teat canal orifice, distal teat canal perimeter, and distal teat canal surface. In the first trial, we verified the repeatability of scanning over time with a mixed model. During the second trial, significant changes after milking were observed for all measured traits of teat morphology except teat end width. The traits from the distal teat canal and its orifice were remarkably changed by milking: distal teat canal orifice, +28.9%; distal teat canal perimeter, +25.0%; and distal teat canal surface, +41.5%. Comparing multiparous versus primiparous cows, higher values of teat width, teat end width, and teat canal length were observed in the older animals. Testing the effect of milk yield on teat dimensions, cows with milk yields >11.0 kg/afternoon milking were found to have larger teat widths, teat end widths, and cistern widths before attachment of the cluster. Furthermore, we observed associations of inner teat morphology toward bacterial counts in the appropriate milk. Regarding this udder health-related parameter especially, the newly established traits showed a connection. Teats in which milk showed bacterial growth had larger distal teat canal perimeters and distal teat canal surfaces. High-resolution ultrasonographic scanning of dairy teats allowed a detailed visualization of the inner morphology. The applied procedure can therefore serve as a useful tool for comparison and evaluation of different milking techniques by analyzing the resulting changes of the morphological traits. The thorough description of teat tissue can also be applied for drawing conclusions on the status of the teat canal's physical and mechanical defense function.

Sonographic findings of congenital bovine teat and udder affections

The objective of this study was to elucidate sonographic findings of congenital affections of bovine teat and udder. The present study was carried out on twelve bovine patients presented to Teaching Veterinary Clinical Complex, College of Veterinary and Animal sciences, Palampur. Various congenital affections observed were ectopic udder, congenital teat fistula, conjoined teat and congenital athelia. An ectopic udder was evident with functional gland cistern and teat cistern and was having a mixed echogenic mass of tissue. Congenital teat fistula showed an accessory full-thickness opening in the lateral teat wall. The conjoined teat was revealed as an accessory hypoechoic tubular cavity found adjacent to the normal teat cistern. Congenital athelia was evident with the absence of teat cistern and streak canal. The longitudinal scan at the level of glandular region revealed an anechoic gland cistern. Based on the sonographic evaluation of congenital teat and udder affections, the ultrasonography proved as a vital diagnostic aid for diagnosing various insidious congenital udder and teat disorders. Sonography equips the surgeon/Clinician in ascertaining the prognosis and helps in the future aspect of bovine udder and teat disorders management and formulation of a precise and efficient therapeutic plan.

Application of colour Doppler and three-dimensional (3D) ultrasonography for visualization of mammary gland structures in goats

The aim of the present study was to evaluate the potential of colour Doppler and three-dimensional ultrasound for visualization of mammary gland structures in goats. Ten Bulgarian white milk goats, aged from 2 to 4 years, weighing 48–54 kg were used. Mammary gland scans were performed via the transcutaneous approach, using 11.0 MHz linear transducer for teat and 5.0 MHz transducer for udder parenchyma. Colour Doppler ultrasonography permitted the visualization of blood vessels in the udder parenchyma, the teat wall skin and the Furstenberg’s venous ring at the boundary between gland cistern and teat cistern. After differentiation of blood vessels, it was possible to determine the direction and velocity of blood flow. The three-dimensional (3D) ultrasonography of caprine mammary gland was capable of visualization of detailed description of the following morphological structures: papillary orifice, rosette of Furstenberg, teat wall, teat and gland cisterns, the parenchyma and the lactiferous ducts. The papillary orifice was seen as a small structure at the tip of the teat, and immediately above it, the teat canal was seen as a thin white band. The 3D image of the rosette of Furstenberg represented a clearly observable thickening at the boundary between the teat canal and the teat cistern. The 3D image of the teat wall allowed for differentiation of its three layers. In the region of the gland cistern, the lactiferous ducts and the parenchyma were distinguished, as well as the boundary between teat and gland cisterns. The analysis of results indicated that colour Doppler ultrasound permits the visualization of mammary blood vessels and their differentiation from anechoic lactiferous ducts and milk in teat and gland cisterns. The three-dimensional (3D) ultrasound check provides an opportunity for detailed observation of all morphological mammary gland structures of goats, which could serve as a background for detection of occurring pathological changes. The main advantage of 3D ultrasonography is the possibility for in-depth observation of the different udder parts, which allows for a more precise diagnostics.

Reduced claw vacuum and b-phase during low milk flow does not impact oxytocin release and milking performance.

Oxytocin release, milking characteristics, and teat condition were investigated with reduced claw vacuum and pulsation settings compared to milking at regular settings with or without pre-stimulation. The reduced vacuum and pulsation settings during low milk flow are expected to protect the teat tissue before the occurrence of milk ejection at the start of milking, and at the end of milking during a potential overmilking period, i.e. at a milk flow &lt;200 g/min. Seven cows were machine-milked either after a 60 s manual pre-stimulation, or without pre-stimulation and reduced vacuum and pulsation settings, or at full vacuum and normal pulsation during the start of milking. Plasma oxytocin (OT) concentration increased similarly in response to manual pre-stimulation and to both milking with reduced, or with full vacuum and pulsation settings, however delayed by 1 min if the cluster was attached without pre-stimulation. In all treatments OT concentrations remained elevated throughout milking. Milk flow curves were mostly non-bimodal at milkings after manual pre-stimulation and bimodal at milkings without pre-stimulation. The main milking time was shorter and average milk flow was higher during milking after pre-stimulation, but did not differ between treatments without pre-stimulation. Milk yields and peak flow rates were not affected by treatments. Either reduced or full vacuum settings were again applied during an intended overmilking from 200 to 100 g/min of milk flow towards the end of milk harvest. Pre-milking teat ultrasound cross sections were recorded one day before the experiment started. Post-milking ultrasound cross sections were performed at 15 min after each experimental milking. Teat wall thickness was increased after milking as compared to pre-milking but did not differ among treatments. In conclusion, OT release and milking performance are similar if milking is performed with pre-stimulation, or without pre-stimulation but reduced claw vacuum and b-phase during low milk flow.

Vacuum levels and milk-flow-dependent vacuum drops affect machine milking performance and teat condition in dairy cows

Different levels of claw vacuum during machine milking may influence milking performance and teat condition. The claw vacuum acts on the teat and is responsible for removal and transport of milk but is also causing potential effects on the teat tissue. In the absence of milk flow, the claw vacuum is similar as the system vacuum. During milk flow, the claw vacuum drops to lower levels depending on lifting height and tube length and diameter, which may influence milking performance and the mechanical load on the teat tissue. The goal of the present study was to investigate the effects of high system vacuum and extremely low claw vacuum during milk flow on milking performance and teat condition after milking recorded by ultrasound. Treatments were control (treatment 1) with a system vacuum of 42 and a minimum claw vacuum during milk flow of 33 kPa; treatment 2 representing a system vacuum of 50 kPa, with a minimum claw vacuum almost similar as treatment 1 (34 kPa); and treatment 3 with the same system vacuum as treatment 1 but a claw vacuum drop during milk flow down to 24 kPa. Total milk yield was similar in all treatments, but strip yield was lower in treatment 3 than in the other treatments. Milk flow was similar in treatment 1 and treatment 2, but was reduced in treatment 3, thus causing a prolonged milking time in treatment 3. Teat wall thickness was increased and teat cistern diameter was decreased in treatment 2 as compared with the other treatments. The results demonstrate that the minimum claw vacuum had the main influence on milking performance independent of the level of the system vacuum and related vacuum drops and a low minimum claw vacuum caused low milk flow and long milking times. Teat condition at the end of milking, however, was mainly dependent on the system vacuum, and the load on the teat tissue was obviously increased at a system vacuum of 50 kPa. This effect was obviously occurring toward the end of milking when milk flow decreased and hence the milk flow dependent vacuum drop disappeared. Therefore, an early cluster detachment should be considered to avoid an increased effect on the teat tissue. Estimates of simulated early detachment levels in the present study of up to 1,000g/min lead to the assumption of minimal milk loss at simultaneously shorter machine-on time through the avoidance of lowest milk flow at the end of milking.

Antigen-Specific Mammary Inflammation Depends on the Production of IL-17A and IFN-γ by Bovine CD4+ T Lymphocytes.

Intramammary infusion of the antigen used to sensitize cows by the systemic route induces a local inflammation associated with neutrophil recruitment. We hypothesize that this form of delayed type hypersensitivity, which may occur naturally during infections or could be induced intentionally by vaccination, can impact the outcome of mammary gland infections. We immunized cows with ovalbumin to identify immunological correlates of antigen-specific mammary inflammation. Intraluminal injection of ovalbumin induced a mastitis characterized by a prompt tissue reaction (increase in teat wall thickness) and an intense influx of leukocytes into milk of 10 responder cows out of 14 immunized animals. The magnitude of the local inflammatory reaction, assessed through milk leukocytosis, correlated with antibody titers, skin thickness test, and production of IL-17A and IFN-γ in a whole-blood antigen stimulation assay (WBA). The production of these two cytokines significantly correlated with the magnitude of the milk leukocytosis following the ovalbumin intramammary challenge. The IL-17A and IFN-γ production in the WBA was dependent on the presence of CD4+ cells in blood samples. In vitro stimulation of peripheral blood lymphocytes with ovalbumin followed by stimulation with PMA/ionomycin allowed the identification by flow cytometry of CD4+ T cells producing either IL-17A, IFN-γ, or both cytokines. The results indicate that the antigen-specific WBA, and specifically IL-17A and IFN-γ production by circulating CD4+ cells, can be used as a predictor of mammary hypersensitivity to protein antigens. This prompts further studies aiming at determining how Th17 and/or Th1 lymphocytes modulate the immune response of the mammary gland to infection.