Teat Orifice Research Articles

The association between teat shape and bimodal milk ejection in Holstein dairy cows

Our objectives were to investigate the association of teat shape with (1) bimodality (2) incremental milk flow rates (average flow rates during the first 15 s, 15-30 s, 30-60 s, and 60-120 s of milking), and (3) peak milk flow rate in Holstein dairy cows milked 3 times per day. In this prospective cohort study, we analyzed 220,928 milking observations that were collected from 2,520 cows from a single dairy herd over a period of 31 d. Teat shape was visually assessed and classified into 1 of 4 categories as follows: (1) triangular barrel and pointed teat end (TP), (2) square barrel and round teat end (SR), (3) square barrel, round teat end, and flat in the area of the teat orifice (SRF), and (4) square barrel and flat teat end (SF). Individual cow-level milk flow rates were obtained using electronic on-farm milk meters. We considered bimodality to be present if any of the incremental milk flow rates (flow rates during 15-30 s, 30-60 s, or 60-120 s) were lower than any of the previous rates (flow rates during the first 15 s, 15-30 s, or 30-60 s). The frequency distribution of cows with different teat shapes was as follows: TP, 96 (3.8%); SR, 1,751 (69.5%); SRF, 617 (24.5%); and SF, 56 (2.2%). A generalized linear mixed model revealed differences in the odds of bimodality among cows with different teat shapes. Compared with cows in category SR, the odds (95% confidence interval) of bimodality of cows in other categories were as follows: TP, 0.68 (0.48-0.97); SF, 1.96 (1.21-3.19); and SRF, 1.46 (1.23-1.72). General linear mixed models indicated an association between teat shape and all incremental milk flow rates, with higher milk flow rates being present for cows with teat shapes in the SRF and SF categories. The general linear mixed model for the dependent variable peak milk flow rate indicated an association between teat shape and peak milk flow rate. Least squares means and 95% confidence intervals were 5.1 (4.9-5.3) kg/min for TP, 5.8 (5.5-6.1) kg/min for SF, 5.6 (5.5-5.7) for SRF, and 5.3 (5.3-5.4) for SR, respectively. We conclude that in this study cohort, bimodality is more likely to occur in cows with flat teat ends compared with those with a round teat ends. We attribute this relationship to the difference in milking speed across cows with different teat shapes. Teat shape may serve as a useful phenotype to identify cows that are more likely to exhibit bimodality. Because our study population was unique, future studies considering different circumstances such as breed, milking system, and milking routine are needed before results can be extrapolated.

Infrared Thermography of Teat in French Dairy Alpine Goats: A Promising Tool to Study Animal-Machine Interaction during Milking but Not to Detect Mastitis.

There is a need to develop tools for mastitis management in goats and to measure the effects of milking machines on teats. Infrared thermography (IRT), as shown in cows, was a good candidate for early mastitis detection and focusing on milking equipment and settings implicated in potential problems. The aim of this study was to test IRT to detect udder inflammation and the effects of mechanical milking on teats in relation to inflammation status, udder balance, and teat shape in Alpine goats. IRT spectra were compared before and after milking in 551 goats from three commercial herds compared to their individual SCC (somatic cell count). We found no regression or trend between logSCC and IRT measurement or response to milking, even in highly inflamed goat udders. The effect of milking was significant (p < 0.05) with global temperature reduction after milking, but differences were seen between teat parts and unbalanced half udders. The highest reduction in skin temperature was observed at the teat orifice (-1.06 ± 0.05) and the lowest at the teat barrel (-0.37 ± 0.05). The teats with long barrels showed more IRT reactions, which clearly indicates poor adaptation to the liners used. In conclusion, the IRT was not able to detect mastitis, but it is a good tool to diagnose the effects of the milking machine in order to adapt milking equipment and settings to the goats and improve their welfare.

BILATERALTEAT LACERATION AND ITS SUCCESSFUL SURGICAL MANAGEMENT IN HOLSTEIN FRIESIAN CROSSBRED CATTLE

A 5.5 years old Holstein Friesian crossbred cattle was presented with a history of traumatic injury by barbed metallic wire on right fore-teat six hours before. Clinical examination revealed full-thickness, bilateral, longitudinal laceration of the same teat, extending from base of the teat to the distal teat orifice with leakage of milk. Prompt reconstructive surgery was performed under sedation and local anesthesia to repair the laceration. The closure of the teat cistern was performed by suturing the laceration in three layers.Post-operative care included intra-mammary and systemicantibiotic therapy with NSAID for five consecutive days along with daily antiseptic dressing of the wound and regular drainage of milk via the fixed infant feeding tube in the teat cistern. The animal had shown uneventful recovery without any complication with removal of skin sutures on 10th post-operative day and started hand milking from the same teat on 20th post-operative day.

Measurement of Mammary Blood Flow in Lactating Camels (Camelus dromedarius) Using Antipyrine Absorption Method

Mammary blood flow has been measured in human breast as well as cow, sheep and goat udders. According to the available literature, mammary blood flow has not been measured in lactating camels. So, the objective of this research was to measure mammary blood flow (MBF) in lactating camel. Data from two lactating camels were used to measure MBF using the antipyrine absorption method. Following complete manual removal of the milk from the udder, 3g of antipyrine dissolved in 30mL of distilled water was injected into each udder gland by the teat orifice. Blood samples were collected simultaneously from the left and right milk veins and pulmonary artery at 15, 20, 25, 30, 35, and 40 minutes following the infusion of antipyrine. Oxytocin (20IU) was injected intravenously 45 min following the infusion of antipyrine, and the volume of the milk removed by manual milking from each udder quarter was measured. Concentrations of antipyrine in the milk and blood were calculated, and MBF per udder gram per minute was measured. Results showed MBF of 6250ml/min (9000L/24h) for camel number 1 and 7800ml/min (11232L/24h) for camel number 2. Blood to milk ratios were 1200:1 and 1021:1 for camel number 1 and 2, respectively. MBF per gram of udder weight was 735.29ml/min/g and 829.78ml/min/g for camel number 1 and 2, respectively.

Understanding bovine mammary gland niches for staphylococci using different milk sampling techniques

Mastitis is usually caused by a bacterial intramammary infection (IMI) with Staphylococcus being the most commonly isolated genus. The standard method for diagnosing an IMI is to aseptically prepare the teat end and collect milk via the teat orifice into a sterile vial for bacterial culture. While this method has been advocated for decades, there has been debate about the importance of some bacteria isolated from such samples when the milk somatic cell count (SCC) in the mammary quarter is &lt; 200,000 cells/ml (threshold for a healthy mammary gland). Recently, Hiitio et al. (2016) showed that milk samples collected directly from the gland cistern were less likely to contain staphylococcal DNA when using a commercial PCR diagnostic test kit than milk samples that were collected via the teat orifice. Unfortunately, the PCR only differentiated staphylococci into Staphylococcus spp. and Staphylococcus aureus, and so it is unknown which of the nonaureus staphylococcal (NAS) species may be more likely to inhabit the teat canal than those that cause a true IMI. These data provide preliminary evidence that some staphylococci in milk may be teat canal inhabitants and not intramammary pathogens that cause mastitis. The objective of this study was to determine if some species of staphylococci isolated from milk are only isolated when the sample is collected through the teat orifice and absent in cisternal milk collected using the method described by Hiitio et al. (2016).

Mammary involution and relevant udder health management in sheep

Abstract Objective of the paper is to describe mechanisms leading to mammary involution in ewes and changes taking place in the mammary gland during that period. Mammary involution is the regression of mammary tissue to non-secreting state and takes place as initiated, gradual or senile. In mutton-type production systems cessation of lactation is abrupt, whilst in dairy-type production systems it is progressive or abrupt. The period from cessation of milk removal until the beginning of subsequent lactation period is termed ‘dry-period’ and is distinguished into stage of active involution, stage of the ‘steady-state’ involution and stage of redevelopment and lactogenesis. The ‘dry-period’ is important in health management of sheep for optimum milk production during the subsequent lactation period, as it is necessary for renewal of mammary epithelial cells. Mammary involution is influenced by decreased activity of galactopoietic hormones and local mechanisms in response to milk accumulation in the gland. Milk accumulation plays a major role in triggering apoptosis of epithelial cells. There are two pathways leading to apoptosis, an intrinsic and an extrinsic. During involution, significant histological changes take place in the mammary gland, mainly reduction (up to 3.6% up to the 4th day) of the epithelial area of the gland and increase of its stromal part. The mammary gland is particularly susceptible to infections after cessation of lactation; progressively, that changes; a keratin plug is formed at the teat orifice, leucocytes accumulate in the gland and concentrations of immunoglobulins and lactoferrin increase. Udder health management at the end of a lactation period aims to cure infections that have occurred during the previous lactation period and prevent new intramammary infections during the ‘dry-period’. Culling ewes with at least one mammary gland permanently damaged or ones chronically affected or others with incidents of relapsing mastitis or not fully respondent to mastitis treatment during the preceding lactation period contributes to decrease of veterinary expenses for mastitis control in the flock, elimination of sources of potential infection for other animals in the flock and decrease of flock bulk somatic cell counts in the subsequent lactation period. Culling should be complemented with intramammary antibiotic administration at the end of a lactation period. In many clinical studies from around the world, administration of antimicrobial agents at the end of a lactation period has been found beneficial. Antibiotic administration at drying-off may be performed to all animals in a flock (‘complete’) or only to those considered to be infected (‘selective’). In all cases, maintenance of the prescribed withdrawal periods is essential to safeguard public health. The procedure should always be applied as part of a strategic udder health management plan in a flock; implementation improves the welfare of animals and affords significant financial benefits to the farmer. Correct udder health management in ewes at the end of a lactation period will contribute to improved mammary health for the forthcoming lactation period.

Genetic parameters for the external udder morphology in commercial farms of Istrian sheep from Croatia

Istrian sheep is a local breed with superior milk yield and composition. Excellent udder shape of this breed needs to be preserved in future, since it’s economic value resides within the artisanal cheese production. Genetic parameters for the teat angle (Alpha) and the height of the cisternal part below the teat orifice (Cis) were estimated in order to evaluate the possibility for conservation of udder traits amiable for machine milking. Udder morphometry of the 240 registered Istrian ewes was measured from digital photographs of the posterior view of the udder on 10 commercial farms three times during lactation. Original pedigree records were trimmed to four recent generations. Heritabilities were estimated using single trait animal model. The stage of the lactation, interaction of lactation number, month of lambing and the farm were fixed effects, and the additive genetic value of the individual and permanent environment of the individual were random effects. Estimated heritability was 0.05 for Alpha and 0.71 for Cis mid-lactation measurements. Measurements of Cis during lactation did not result in a significant additive effect. The result shows potential in estimating genetic parameters of important udder traits in small commercial dairy ewe populations, using the digital measurements, given the reduction of non-genetic variability in the sample.

A retrospective study of surgical affections of mammary glands in cattle and buffaloes and their management in the field.

The present retrospective study was conducted from 2003 to 2015 in Egypt to document common surgical affections of the udder and teat in cattle and buffaloes, and determine medical and surgical treatment options that are feasible in a field setting. We diagnosed 19 different surgical affections and classified them into 4 groups according to their location. Teat orifice affections (12.41%) included imperforate teat, contracted teat orifice, enlarged teat orifice, and black spot. Teat cistern affections (23.76%) included teat fistula, dilated teat cistern, teat polypi, and webbed teat. Teat surface affections (50.35%) included sore teat, supernumerary teat, sloughed teat, teat papilloma and fibropapilloma, teat wounds, and teat viral lesions. Udder affections (13.48%) included hypermastia, udder wounds, and suppurative and gangrenous mastitis. In cattle, the number of surgical affections located on the teat surface (20 ± 5.4) was significantly higher compared with other locations as well as compared with buffaloes (P<0.05). No treatment was indicated in 24% of recorded cases. Medical and surgical treatment was indicated in 73.75% of affected animals. Favorable results were achieved with the recommended treatments when applied in the field.

Prevalence of udder and teat affections in large ruminant in Beni-Suef and El-Fayoum provinces

This investigation was carried out on 5457 animals; among which, 3916 cows, 1531buffaloes and 10 she-camels in Beni-Suef and Fayoum provinces. Animals weresubjected to clinical examination to study the congenital and acquired udder andteat surgical affections. Clinical findings of affected animals were recorded. It hasbeen found that the prevalence of teat and udder affections were: in cattle(19.87%; 778/3916), 141 (3.6%) had congenital anomalies, (hyperthelia 2.17%,leaker 0.38%, athelia 0.26%, pendulous udder 0.20%, hypermastia 0.26%,hypoplasia of mammary gland 0.13%, hyperplasia of teat 0.08%, teat obstruction0.08% and fistula 0.05%)and 637 (16.267%) suffered from acquired affections(fibrosis 6.26%, mastitis 3.29%, pendulous udder 1.18%, edema 1.15%,fistula/wound 0.84%, teat obstruction 0.66%, teat stenosis 0.66%, ulcer/crack0.64%, abscess 0.54%, hematoma 0.26%, seborrhea 0.23%, impetigo 0.18%,neoplastic growths 0.18%, udder gangrene 0.15% and teat gangrene 0.05%). Inbuffaloes (11.43%; 175/1531), 11 (0.72%) had congenital anomalies (hypermastia0.59%, hyperthelia 0.07% and fistula 0.07%), and 164 (10.71%) had acquiredaffections (fibrosis 2.81%, ulcer/cracks 2.09%, mastitis 1.89%, seborrhea 1.44%,obstruction 0.91%, edema 0.46%, hematoma 0.33%, fistula/wound 0.26%, teatgangrene 0.26%, stenosis 0.13%, abscess 0.07% and impetigo 0.07%). In shecamels, no congenital anomalies were recorded with only one animal showed anacute mastitis and other had a teat orifice obstruction

Gross anatomy and ultrasonography of the udder in goat

Abstract Introduction: The udder is a very important structural and physiological component in all dairy animals, so the precise knowledge of its normal gross morphology is fundamental for the clinical examination. Objective: The current study aimed to clarify the gross anatomical characteristics and ultrasonographic findings of the udder in Egyptian native breeds of goat (Baladi goat). Materials and Methods: Thirteen healthy Baladi goats during lactation period were grossly investigated and then they were examined through B-mode ultrasonography. Two specimens were used for corrosion casting and the remaining specimens were subjected to the anatomical dissection. Results: The gross anatomical investigation revealed that the udder of goat was consisted of two halves; each one had mammary body and teat, and it was suspended in the ventral abdominal wall and pelvic floor through the medial and lateral suspensory laminae. Moreover, each half was composed of a single mammary unit which included the mammary glandular parenchyma, lactiferous ducts, lactiferous sinus and teat canal ended by a teat orifice. These mammary structures showed variant echogenicity during ultrasonographic examination according to their reflective intensity to the ultrasound. Conclusion: The morphological features and ultrasonographic findings obtained in this study could assist in the further diagnosis of several pathological conditions of the udder of goat.

Association of anatomical characteristics of teats with quarter-level somatic cell count

Mastitis occurs after bacteria successfully traverse the teat orifice and cause an intramammary infection. Anatomical characteristics of the teat are potential risk factors for infection. The objective of this study was to identify potential associations between anatomical characteristics of teats and quarter-level somatic cell count (QSCC) from cows on larger dairy farms in Wisconsin. Teat dimensions (length and diameter at the teat barrel and apex) were measured, and hyperkeratosis scores were assessed for 3,713 quarters of 959 cows on 9 dairy farms. The SCC of quarter milk samples obtained from those teats was determined. Multivariate models were used to determine associations of teat anatomical characteristics with QSCC. Subclinical mastitis was defined as a quarter milk sample with SCC of >150,000 cells/mL. Teat dimensions and milk components varied among farms. In the group of farms enrolled in this study, prevalence of subclinical mastitis in mammary gland quarters ranged from 13.6 to 28.9%. An interaction of teat apex diameter and quarter position (front or rear) was identified for QSCC. For both front and rear quarters, a tendency existed for narrower teat barrels to be associated with increased QSCC. However, for front quarters only, greater diameter of the teat apex was associated with increased QSCC. Teat shape (square or triangular teats) was not associated with QSCC. Milk samples obtained from teats with hyperkeratosis scores of very rough had greater QSCC compared with milk samples obtained from teats with hyperkeratosis scores of normal, smooth ring, or rough ring.

İneklerde Meme Başı Hiperkeratozunun Rastlantısı ve Süt Somatik Hücre Sayısına Etkisi

Objective: In this study, the frequency of hyperkeratosis and its effect on milk somatic cell counts were researched. Material and Methods: A total of 2332 teats in 583 Holstein cows in different stage of lactation were evaluated on the base of the criteria of morphological structure of the teat end and teat length, milk yield and number of lactations. Macroscopic appearances of lesions on the teat orifice were classified and also were photographed. Somatic cell counts (SCC) were evaluated using the fossomatic method. Results: The SCC was determined to be less than 200.000 cells/mL in 72.8% of the quarters and greater than this in 27.2%. Forty-nine percent of the teat ends were normal while hyperkeratosis was identified in 51%. Hyperkeratosis degrees of 1, 2, 3, 4 and 5 was determined in 17%, 13.8%, 9.2%, 5% and 6% respectively. The study findings demonstrated that there was a significant rise in SCC parallel to increasing severity of hyperkeratosis (p<0.001) and that even mild hyperkeratosis could result in an increase in SCC (p<0.05). A significant correlation was determined between severe hyperkeratosis and pointed teat ends (p<0.001). The relationship between hyperkeratosis and milk yield was determined to be significant (p<0.001). However the connection between number of lactations and teat length with hyperkeratosis was not identified as statistically significant. Conclusion: It was concluded that pointed teat ends have a greater tendency to develop hyperkeratosis, the development of hyperkeratosis increased as milk yield dropped and hyperkeratosis could result in a significant increase in SCC and consequently pose a risk to udder health.

Teat Morphology Characterization With 3D Imaging.

The objective of this study was to visualize, in a novel way, the morphological characteristics of bovine teats to gain a better understanding of the detailed teat morphology. We applied silicone casting and 3D digital imaging in order to obtain a more detailed image of the teat structures than that seen in previous studies. Teat samples from 65 dairy cows over 12 months of age were obtained from cows slaughtered at an abattoir. The teats were classified according to the teat condition scoring used in Finland and the lengths of the teat canals were measured. Silicone molds were made from the external teat surface surrounding the teat orifice and from the internal surface of the teat consisting of the papillary duct, Fürstenberg's rosette, and distal part of the teat cistern. The external and internal surface molds of 35 cows were scanned with a 3D laser scanner. The molds and the digital 3D models were used to evaluate internal and external teat surface morphology. A number of measurements were taken from the silicone molds. The 3D models reproduced the morphology of the teats accurately with high repeatability. Breed didn't correlate with the teat classification score. The rosette was found to have significant variation in its size and number of mucosal folds. The internal surface morphology of the rosette did not correlate with the external surface morphology of the teat implying that it is relatively independent of milking parameters that may impact the teat canal and the external surface of the teat.

Effect of presampling procedures on real-time PCR used for diagnosis of intramammary infections with Staphylococcus aureus in dairy cows at routine milk recordings

Aseptic procedures for milk sample collection are considered crucial for bacterial culture to avoid misdiagnosis and subsequently unnecessary treatment or culling. The objective of this field study was to investigate the effect of presampling procedures on the PCR-positivity at cycle threshold value ≤37 of real-time PCR assay to detect Staphylococcus aureus from composite milk samples at routine milk recordings while accounting for known cow-level risk factors. A total of 1,199 dairy cows from 6 herds with conventional milking parlors were sampled and tested by PCR in 2011. Following the farmers’ routine premilking preparations, 624 cows of the 1,199 cows were randomly selected for bacterial culture preceded by presampling procedures. These procedures were: cleaning of udder teats, removing the first streams of milk, and 70% alcohol teat disinfection. Data on parity, somatic cell counts, days in milk, daily milk yield, fat %, and protein % were extracted from the Danish Cattle Database, whereas energy-corrected milk was calculated based on the latter 3. The within-herd prevalence of intramammary infections with Staph. aureus was 31%, ranging from 16 to 48% in the 6 herds. Univariable analysis showed that the presampling procedures, somatic cell counts, energy-corrected milk, and days in milk were significantly associated with PCR-positivity, whereas parity was not significant. A multivariable model with herd as random effect showed that presampling procedures decreased the chance of being PCR-positive to 0.75 (95% CI; 0.58–0.97) compared with cows where the presampling procedures were not carried out. In conclusion, presampling procedures decreased the cow’s chance of being PCR-positive to Staph. aureus. Presampling procedures appeared to improve the specificity of PCR for detection of Staph. aureus by reducing false positives through destruction of Staph. aureus bacteria colonizing or contaminating the teat skin, orifice, and canal. Random herd effects accounted for only 8.9%, indicating that the cluster effect due to herd management on the PCR positivity to Staph. aureus was virtually negligible.

Prevalence, incidence and risk factors of heifer mastitis

Traditionally heifers, as calves and as primiparae, have been thought of as a group as free of mastitis. Without appreciable lacteal secretion, there is reduced nutrient fluid available to support growth of intramammary pathogens. Contagious mastitis is primarily transmitted at milking time and the milking process affects the patency of the teat orifice which can increase the risk of development of environmental mastitis. Logically therefore prepartum heifers should be free of intramammary infections. During the last 20 years there have been numerous investigations describing the nature of mastitis in heifers and thus the dogma that heifers are free of this disease has been challenged. The purpose of this manuscript is to review that literature describing heifer intramammary infections that cause both subclinical and clinical disease. Mammary quarter infection prevalence ranges between 28.9–74.6% prepartum, and 12.3–45.5% at parturition. Generally, the pathogens that cause mastitis in heifers are the same as those that cause infections in the older cows. In all but one study reviewed, coagulase-negative staphylococci (CNS) are the most prevalent cause of subclinical intramammary infections in heifers. Coagulase-positive staphylococci (CPS) in some studies are the second most prevalent pathogens, while in other studies the environmental mastitis pathogens are more prevalent. The risk factors for subclinical mastitis appear to be season, herd location, and trimester of pregnancy; all suggesting that management can have an impact in control of this disease prepartum. With respect to clinical mastitis, the most prevalent mastitis pathogen has been reported to be CNS in one study and CPS, or environmental mastitis pathogens, in other studies. The heifer is most at risk for clinical mastitis during the periparturient period. Risk factors found are related to diet, mammary gland factors such as edema and leaking of milk, and factors associated with the change in management and introduction of the heifer to the milking herd.

Field Study on Protocols for Evaluation of Teat Skin Conditions

Different protocols to evaluate teat skin status under field conditions based on scoring and on the measurement of pH and hydration of teat skin were evaluated. After determination of the teat score for all eligible animals in a commercial dairy herd, 50 of them were chosen, based on their pre-trial average teat score, and separated in two groups. Two different post-dipping products with the same amount of disinfectant, but with a different concentration of emollient were applied. All four teats were assessed with the corneometer and pH probes. A digital picture of each teat skin and teat orifice was taken with a digital camera. Hydration and pH data were analysed by anova with repeated-measurement factors, while teat skin and apex score patterns, were assessed by the means of Mann-Whitney test; between- and within-group changes were assessed by the mean of Mantel-Haenzel chi-square statistic. Data showed that teat skin pH and hydration could be assessed under field conditions and they were influenced by teat conditioning. The approach based on evaluating odds for scores, stratified for sampling and for treatment, was found to be a sensitive and informative way to compare the changes between and within treatment groups.

Cow-Related Risk Factors for Milk Leakage

Milk leakage in dairy cows is a symptom of impaired teat sphincter function. Milk leakage is related to an increased risk of mastitis in heifers and cows, and causes hygiene problems. The aim of our study was to assess whether teat shape, condition of teat orifice, and peak milk flow rate are risk factors for milk leakage. We conducted a longitudinal observational study in 15 German dairy farms in which cows were maintained in loose housing. The farms were visited monthly at 2 consecutive milkings. During the evening milking, milk flow curves were measured with the LactoCorder. Milk leakage was recorded during the subsequent morning milking, when cows entered the milking parlor. Immediately after detachment of the milking cluster, teat shape, teat end shape, and condition of the teat orifice of cows were assessed between 9 and 100 d in milk (DIM) and during late lactation (>250 DIM). Data from 1600 cows were analyzed. Milk leakage was treated as the binary response variable in a logistic regression model with herd as a random effect. Primiparous cows with high peak milk flow and teat canal protrusion were at greater risk of milk leakage. High peak milk flow rate, short teats, teat canal protrusion, inverted teat ends, and early lactation increased the risk of milk leakage in multiparous cows. Random herd effects accounted for only 10% of the total variation, indicating that the impact of management or other herd-level factors on the occurrence of milk leakage is virtually negligible for practical purposes.

Influence of Vacuum Level and Overmilking on Udder Health and Teat Thickness Changes in Dairy Ewes

The effects of vacuum level and overmilking on udder health were studied in ewes. Vacuum levels of 36 and 42 kPa were assigned to two groups of 23 Manchega ewes in a crossover study design with two experimental periods of 5 wk for each. Moreover, for each ewe, one teat was overmilked 1.5 to 2min at all milkings during these 10 wk. The milking machine used had a midlevel milkline and pulsation was fixed at 180 cycles per min and a pulsation ratio of 50:50. Bacterial exposure of all teats was increased by dipping them in a suspension of Staphylococcus simulans at eight milkings of each period. New intramammary infections (IMI) were not significantly affected by the vacuum level used (18 and 23% of ewes infected, at 36 and 42 kPa, respectively) or application of overmilking (9 and 11% of half udders infected without and with overmilking, respectively). Likewise, neither factor significantly affected the somatic cell count (SCC) of the milk. Teat thickness changes after milking varied significantly due to the presence of overmilking (−13.6 and −7.4%, in teats not overmilked and overmilked, respectively) but were not affected by vacuum level. At no time were any lesions or variations visibly noted in the teat walls or orifice. So, in this work we were unable to demonstrate that the vacuum and overmilking levels assayed, both used with a pulsation rate of 180 cycles/min, have an important effect on the state of udder health in the short term. Furthermore, it was also observed that, in absence of IMI, the two factors studied did not cause irritation of any kind in the gland that might influence the SCC of the milk.

Classification and Longitudinal Examination of Callused Teat Ends in Dairy Cows

To examine the development of teat end callosity thickness and roughness in early lactation and to quantify cow factors of interest, a system to classify teat end condition was developed. A distinction was made between rough and smooth rings around the teat orifice. In addition, a classification of the degree of callosity was developed. Kappa coefficients for the repeatability of scoring by this classification system by different workers were 0.71 for teat end callosity thickness and 0.86 for teat end callosity roughness. The teat end callosity classification system was used for a longitudinal study with 40 cows during the first 14 wk of lactation. Models were built to predict teat end callosity thickness and roughness, machine-on time, and milk yield. For the response variables, teat end callosity thickness, machine-on time, and milk yield, the consecutive measurements appeared to follow a lactation curve model with a subject-specific general slope and intercept. Teat end callosity increased rapidly the first 8 wk. Cow factors such as days in milk, parity, machine-on time, and teat end shape were associated with the degree of teat end callosity, and the probability of the callosity ring to become rough. Teat end callosity thickness did not decrease within the 14-wk trial period for most teats. Pointed or round teat ends showed more callus than inverted teat ends. Longer machine-on time resulted in a higher probability of the callosity ring to become rough. Rear teats showed less callosity than front teats in this study.

乳牛の潜在性乳房炎と乳頭口異常の関連

乳牛の潜在性乳房炎と乳頭口異常の関連