The Effect of Post Milking Teat Dip and Suckling on Teat Skin Condition,Bacterial Colonisation,and Udder Health

The teat skin of cows was scored (1: smooth as silk; 2: smooth; 3: slightly rough; 4: rough; 5: cracked; and 6: sores) by trained technicians who moved their fingers down the barrel of the teat with a light touch. Technicians ranked the same population of teats in the same rank order, but their mean values differed by half a score which probably could be related to the skin condition of their own fingers. Half udder experiments were carried out for 6 months at 4 farms with 35 to 52 cows each. A postmilking teat spray with 10% glycerol improved teat skin condition (p<0.10) compared with no teat spray. A postmilking teat spray with 120 ppm chlorine dioxide did not influence teat skin condition compared with no teat spray. No differences in udder health could be proven between treatments. Control studies revealed that 10% glycerol as an emollient of a postmilking teat spray improved teat skin condition within 3 weeks from being slightly rough to being smooth for lactating cows (p<0.05) but not for dry cows having smooth teat skin. Neither glycerol nor chlorine dioxide influenced absolute number of bacteria on teat skin after a challenge with Streptococcus uberis and Staphylococcus aureus but half life of S. aureus on unsprayed teats was longest (p = 0.05). Suckling made teat skin more rough than machine milking. Nevertheless, suckling lowered the number of esculin positive bacteria on the teat skin. We concluded that the condition of healthy teat skin (scores 1–4) has no influence on bacterial colonisation in the absence of cracks and sores (scores 5–6).     

Presence of sub-epithelial lymphoid tissues in the teat of ewe-lambs and adult ewes

In the first part of the study, 24 clinically healthy teats from non-lactating ewe-lambs were examined bacteriologically and histologically. No bacteria were isolated from any of these teats; lymphocytes were observed in teat cisterns of six teats (25%) from three ewes. In the second part, 87 teats from adult ewes were examined; their origin was from lactating mammary glands with no bacteria isolated (n = 23), from glands after lactation with no bacteria isolated (n = 25), from lactating glands with bacteria isolated (n = 22) or from glands after lactation with bacteria isolated (n = 17). The salient histological feature was sub-epithelial leucocytic infiltration. In teat cisterns, lymphocytes were the predominant cell type and in teat ducts, lymphocytes and neutrophils were seen in equal proportions. Sub-epithelial lymphoid nodules, some with germinal centers, were detected in 43 (49%) teats; their majority was observed at the border between teat duct and teat cistern. Presence of bacteria was significantly associated with presence of leucocytic activity (P < 0.001) and with presence of lymphoid nodules (P = 0.032). We conclude that the presence of induced sub-epithelial lymphoid tissue at the border between teat duct and teat cistern appears to be important in protecting the mammary gland during the early stages of bacterial invasion.     

Summer mastitis experimentally induced by Hydrotaea irritans exposed to bacteria

Abstract. Summer mastitis is an acute suppurative bacterial infection of the udder in heifers and dry cows. To ascertain the possible role of flies in the transmission of the disease, experimental exposures of recipient heifers to Hydrotaea irritans previously exposed to bacteria were carried out. Flies were allowed to feed on secretions from clinical cases of summer mastitis. The pathogens present were the bacteria Staphylococcus aureus, Streptococcus dysgalactiae, Actinomyces pyogenes , Stuart-Schwan cocci, Peptococcus indolicus, Fusobacterium necrophorum and Bacterioides species. The teats of eight heifers were exposed to flies with verified pathogen content. Two teats of each animal were deliberately damaged before fly exposure. One teat was cut, another pricked with insect needles to mimic insect bites. Two of the heifers developed summer mastitis in the quarters where teats had been cut. The bacterial species isolated from these quarters corresponded to those that had previously been fed to the flies. For the first time, it is now demonstrated that H.irritans is capable of transmitting summer mastitis pathogens and so causing summer mastitis in recipient heifers. Lesions on the teat orifice may be a predisposing factor in the development of the disease.     

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.     

Semi-log model for interpreting the results of swabbing surfaces naturally contaminated

Two mathematical models for depicting microbial depletions during six consecutive swabbings of refrigerated tank wall and teat skin were tested. Although a second degree polynomial equation gave a better adjustment of the data, a first degree equation was preferred to calculate the total numbers of micro-organisms possibly retrieved from surfaces by swabbing. This model was used for estimating the level of milk contamination by teat skin.     

Semi-log model for interpreting the results of swabbing surfaces naturally contaminated

Two mathematical models for depicting microbial depletions during six consecutive swabbings of refrigerated tank wall and teat skin were tested. Although a second degree polynomial equation gave a better adjustment of the data, a first degree equation was preferred to calculate the total numbers of micro-organisms possibly retrieved from surfaces by swabbing. This model was used for estimating the level of milk contamination by teat skin.     

Infrared Thermography and Ultrasonography to Indirectly Monitor the Influence of Liner Type and Overmilking on Teat Tissue Recovery

Eight Danish Holstein cows were milked with a 1-mm thick specially designed soft liner on their right rear teat and a standard liner mounted under extra high tension on their left rear teat. Four of the animals were overmilked for 5 min. Rear teats were subjected to ultrasound examination on the first day and to infrared thermography on the second day. Teats were submersed in ethanol 20 min post-milking on the second day. Ultrasonography measurements showed that teat canal length increased by 30–41% during milking. Twenty minutes after milking, teats milked with modified standard liners still had elongated teat canals while teats milked with the soft liner were normalized. Overmilking tended to increase teat wall thickness. Approximately 80% of variability in teat canal length, from before teat preparation to after milking, could be explained by changes during teat preparation. Thermography indicated a general drop in teat temperature during teat preparation. Teat temperature increased during milking and continued to increase until the ethanol challenge induced a significant drop. Temperatures approached pre-challenge rather than pre-milking temperatures within 10 minutes after challenge. Teat temperatures were dependent on type of liner. Mid-teat temperatures post-challenge relative to pre-teat preparation were dependent on overmilking. Thermography and ultrasound were considered useful methods to indirectly and non invasively evaluate teat tissue integrity.     

Problems associated with traditional hygiene swabbing: the need for in-house standardization

AIMS: To investigate factors influencing the recovery of micro-organisms from surfaces using traditional swabbing techniques. METHODS AND RESULTS: Stainless steel squares were inoculated with known levels (approx. 2.7x10(2)-2.7x10(4)) of either Escherichia coli or Staphylococcus aureus and sampled using different swab/solution combinations. Overlaying the coupons with agar allowed colonies remaining on the surface to be enumerated. Conventional cultivation was used to determine the ease with which the bacteria were released from the swabs and the viability of the organisms within the solutions over a 24-h period. Minimal bacterial growth occurred when the samples were stored at 4 degrees C. At room temperature, whilst the presence of nutrients significantly increased bacterial numbers over time, the addition of Tween 80 to nutrient depleted environments significantly reduced the viability of Staph. aureus. The percentage of bacteria released from directly inoculated swabs was significantly higher than that recovered from surface swabs, highlighting the importance of effectively removing bacterial contaminants from a surface. Increasing the level of mechanical energy generated during swabbing increased the number of bacteria removed from a wet surface. However, it is hypothesized that cellular damage, perhaps caused by the swabbing action itself, may have reduced recoverability from a dry surface. Nonetheless, an increased ability to effectively remove bacteria from a surface did not necessarily correlate with higher bacterial recovery, implying that an equally important factor in terms of swabbing efficiency is the ability of a swab to effectively release bacteria into a diluent. CONCLUSIONS: Both swab and wetting solution can influence the number of bacteria recovered. Under the experimental conditions described here, the use of swabs coated with a brush-textured nylon flock in combination with a non-growth-enhancing wetting solution appeared the best system to use when sampling a wet surface. However, this combination may not always be ideal and proper consideration must be given to how the sample is to be taken, transported and, if necessary, stored prior to analysis. SIGNIFICANCE AND IMPACT OF THE STUDY: Careful selection of swabbing materials can increase the sensitivity of traditional microbiological analysis. However, any improvements made are likely to be insignificant in relation to the overall poor performance of the swabbing technique.     

Identification of novel candidate genes for the inverted teat defect in sows using a genome-wide marker panel

The number of functional teats is an important selection criterion in pig breeding. Inherited defects of the udder, such as the inverted teat, do have a considerable negative impact on the nursing ability of the sow. To investigate the genetic background of this defect and the number of functional teats in Swedish maternal lines, samples from 230 Yorkshire pigs were selected for genotyping using the PorcineSNP60K BeadChip (Illumina Inc.), each pig with at least one inverted teat was matched with one non-affected pig (fullsib or pairs with matching herd and gender). A genome-wide association study on these 230 pigs was performed using the two-step approach implemented in GenABEL using 46,652 single nucleotide polymorphisms across all autosomes and the X chromosome. A number of significant regions were identified for the inverted teat defect on chromosomes 2, 10, and 18. Many of the regions associated with the number of functional teats were located in the same or close regions, except two associated markers on the X chromosome and one on chromosome 3. We identified some of the regions on chromosomes previously reported in one linkage and one gene expression study. We conclude, despite being able to suggest new candidate genes, that further studies are needed to better understand the biologic background of the teat development. Despite the in-depth comparison of identified regions for the inverted teat defect done here, more studies are required to allow a clear identification of genetic regions relevant for this defect across many pig populations.     

Development of a methodology to describe udder conformation in sows

The aim of this study was to develop a methodology to measure sow udder conformation to use in studying the correlation between udder traits and piglet survival, health and performance. The steps in the investigation were (i) to assess the repeatability of measures, (ii) to determine if there was an important difference between the two sides of the udder, (iii) to assess the extent of variation between sows, and finally (iv) to verify if the measures differ in a systematic way over the days shortly before farrowing. A total of 24 sows were scored for six conformation traits of the udder measured twice a day, every day from the sows’ entrance into the farrowing crates until farrowing (1 to 4 days later). The data were recorded from both sides when the sow was lying and when she was standing. The measurements taken were: inter-teat distance within the same row (SAMER; mm between the adjacent teat bases); distance from the base of the teats to the abdominal midline, recorded only in a lying posture (B); distance between the teat base and the adjacent teat on the opposite row, recorded only in a standing posture (OPPR), distance from the base of the teats to the ground (FLOOR); teat length (LEN) measured from the tip to the base, and diameter (DIA) measured at the tip of the teat. Intraclass correlation coefficients (ICC) revealed that most udder conformation traits were highly repeatable (ICC>0.8); only DIA and FLOOR had lower repeatability (ICC=0.7). Measurements did not differ by side. In general, the greatest proportion of variance occurred at the sow level. Traits changed little in the days before farrowing, except for a change 1 day before farrowing in DIA, FLOOR and OPPR. Measures which used anatomical landmarks as the reference point were more reliable than those using the floor of the pen. Udder conformation measures can be used as a reliable phenotype for further study. They can be collected on any day shortly before farrowing, and only from one side and in one posture to save time.     

Genome-wide association studies for the number of teats and teat asymmetry patterns in Large White pigs

The number of teats is a morphological trait that influences the mothering ability of the sows and thus their reproduction performances. In this study, we carried out GWASs for the total number of teats and other 12 related parameters in 821 Italian Large White heavy pigs. All pigs were genotyped with the Illumina PorcineSNP60 BeadChip array. For four investigated parameters (total number of teats, the number of teats of the left line, the number of teats of the right line and the maximum number of teats comparing the two sides), significant markers were identified on SSC7, in the region of the vertnin (VRTN) gene. Significant markers for the numbers of posterior teats and the absolute difference between anterior and posterior teat numbers were consistently identified on SSC6. The most significant SNP for these parameters was an intron variant in the TOX high mobility group box family member 3 (TOX3) gene. For the other four parameters (absolute difference between the two sides; anterior teats; the ratio between the posterior and the anterior number of teats; and the absence or the presence of extra teats) only suggestively significant markers were identified on several other chromosomes. This study further supported the role of the VRTN gene region in affecting the recorded variability of the number of teats in the Italian Large White pig population and identified a genomic region potentially affecting the biological mechanisms controlling the developmental programme of morphological features in pigs.     

Effects of housing and management conditions on teat cleanliness of dairy cows in cubicle systems taking into account body dimensions of the cows

Dirty udders and teats result in a higher workload in terms of cleaning before milking and may constitute a risk for udder health. The aim of this prevalence study on 23 farms with very low within-farm variation in cubicle measures and other cubicle characteristics was to identify potentially influencing housing and management factors concerning teat and teat tip soiling. Information about udder soiling, housing and management was collected through direct recording and farmers’ interviews. Height at withers, shoulder width and diagonal body length were measured in 79% to 100% of the cows in each herd. On the basis of the 25% largest animals, compliance with recommendations for cubicle measures was calculated, which was generally rather low. Stepwise regression was used to find predictors for the percentage of dirty teats and of dirty teat tips. The final model on dirty teats explained 58.5% of the variance and contained four factors (F = 6.34, P = 0.0023). Less soiled teats were found on farms that conducted teat dipping after milking (t = −3.21, P = 0.0048), had increased daily cubicle maintenance time (t = −2.58, P = 0.0187), deep-bedded cubicles (t = −2.42, P = 0.0265) and decreasing compliance concerning cubicle length (t = 2.33, P = 0.0317). The final model on teat tip soiling explained 46.0% of the variance and contained three factors (F = 5.39, P = 0.0075). Less soiled teat tips were associated with increasing height of bedding material (t = −2.89, P = 0.0094) and decreasing compliance concerning resting length (t = 2.12, P = 0.0470). Difficult to explain was the association found between increased passage soiling and decreased teat tip dirtiness (t = −1.86, P = 0.0790). Thus, even under relatively restrictive cubicle conditions, a certain increase in teat and teat tip soiling was found with increasing cubicle length. However, at the same time, measures relating to good management may positively affect teat and teat tip cleanliness. In addition, deep-bedded cubicles yielded advantages in this regard. Both regression models for teat and teat tip cleanliness contained similar but not identical predictive variables. This indicates that dirtiness of each particular area may originate from slightly different though related causes. The low correlations found between udder, teat and teat tip cleanliness should be considered in future studies.     

Development and consequences of teat-order in piglets

Observations were carried out on a total of 247 piglets from 34 litters in order to determine the mechanism and formation factors of teat-order, to evaluate its stability, and to determine their relationship with weight gains and dominance hierarchy.The regular observation of 8 litters from birth to 1 month made it possible to determine that formation of teat-order has a progressive trend; initially, the piglets direct themselves towards teats situated near the angles formed by the legs and the body of the mother, and show a clear tendency to move to the front.They first orientate towards a zone of 4 or 5 teats, within which a progressive predominance of 1 or 2 teats develops. For most of the animals, teat-order becomes stable after 7 days. The size of the litter does not seem to influence the development of teat-order or the preference for front or rear teats. Factors involved in this formation could be the sounds produced by the mother, smell and teat morphology, and recognition of the suckling neighbour's teats.Sex, weight at birth and birth order have no influence on teat-order.The animals suckling the 4 front teat pairs seem to gain a little more weight than the others, and a certain relationship seems to exist between position in teat-order and in dominance hierachy, but this is not very marked.     

Effects of amount of milk, milk flow and access to a rubber teat on cross-sucking and non-nutritive sucking in dairy calves

The aim of this study was to test the effects of different amounts of milk, flow rate of milk, and access to a teat after milk intake on non-nutritive sucking on an empty teat and on cross-sucking on other calves in Bos taurus dairy calves. An additional aim was to test if calves prefer to perform non-nutritive sucking on a teat with the taste of milk or on a clean teat. First experiment involved 11 groups of three calves during gradual decrease from 5 to 2.5 and 1 to 0l of whole milk per meal twice daily. Milk flow was either 0.5 or 1l/min, and the teat buckets were either left or removed after milk intake. When the calves were fed with 5l of milk, non-nutritive sucking and cross-sucking decreased (P<0.001), compared to 1 and 2.5l. Removing the empty teat after milk intake increased cross-sucking (P<0.001). Slow milk flow reduced non-nutritive sucking after milk intake (P<0.05), but did not influence cross-sucking. Duration of recorded milk intake was similar with fast flow and 5l of milk, compared to slow flow and 2.5l of milk. The latter combination increased non-nutritive sucking and cross-sucking, suggesting that amount of milk is more important than duration of milk intake.Second experiment was carried out on 12 individually kept calves. The calves received 2.5l of milk either in an open bucket, in a rubber teat bucket, or half/half in both buckets. When not used for feeding, the open bucket and the teat bucket were filled and emptied again to make them 'tasty' with some drops of milk. The tasty teat bucket was either removed or present after milk intake. The calves had always access to a second clean teat bucket. Source of milk had no influence on recorded behaviour after milk intake. The tasty teat was sucked for twice as long as the clean one when both teats were present (P<0.001). When the tasty teat was removed, the calves increased sucking on the clean teat (P<0.001), but decreased total time spent sucking (P<0.001). We conclude that a high amount of milk and the presence of the teat bucket after milk intake reduces cross-sucking, and that a clean teat is less effective in encouraging calves to suck than a teat with taste of milk.     

Effects of freezing and thawing on glycerol mutants of Escherichia coli

The effects of freezing and thawing on the viability of three glycerol mutants of Escherichia coli were determined when glycerol was absent or present in either the intracellular, extracellular, or both intra- and extracellular milieux.The recovery of nonglycerolated cells was related to the combination of freezing and thawing rates. Cell survival was significantly increased when subjected to the same rates of freezing and thawing.The ability of glycerol to protect against irreversible freeze-thawing injury was related to its cellular localization. Survival was markedly enhanced by extracellular glycerol and further increased by the presence of intracellular glycerol. However, intracellular glycerol alone failed to increase cell recovery. The rate of recovery, in respect to extracellular glycerol, was dependent upon both the rate of freezing and the combination of freezing and thawing rates.     

Genome‐wide association QTL mapping for teat number in a purebred population of Duroc pigs

Because of increasing litter size in Western pig breeds, additional teats are desirable to increase the capacity for nursing offspring. We applied genome‐wide SNP markers to detect QTL regions that affect teat number in a Duroc population. We phenotyped 1024 animals for total teat number. A total of 36 588 SNPs on autosomes were used in the analysis. The estimated heritability for teat number was 0.34 ± 0.05 on the basis of a genomic relationship matrix constructed from all SNP markers. Using a BayesC method, we identified a total of 18 QTL regions that affected teat number in Duroc pigs; 9 of the 18 regions were newly detected.     

Studies on the possible role of cattle nuisance flies, especially Hydrotaea irritans, in the transmission of summer mastitis in Denmark

The summer mastitis pathogens Actinomyces pyogenes, Peptococcus indolicus, Bacteroides melaninogenicus ss. levii, Fusobacterium necrophorum and Streptococcus dysgalactiae were isolated from the polyphagous symbovine dipterans Hydrotaea irritans (Fallén) and Morellia sp. caught around dairy heifers on pasture, but not from the haematophagous species Haematobia irritans (L.), Haematobosca stimulans (Meigen), Culicoides sp. and Simulium sp. Secretions from clinical cases of summer mastitis proved to be sources of summer mastitis bacteria for more than 3 weeks despite antibiotic treatment and teat amputation. Taking into account the seasonal activity pattern of Hydrotaea irritans and its topographical distribution on grazing cattle, it appears evident that this fly may play a central role in the establishment and maintenance of the bacterial contamination with summer mastitis pathogens on the teats of healthy cattle. In the present study the survival of A.pyogenes and P.indolicus for 7 days in experimentally infected Hydrotaea irritans, as demonstrated by the recovery of these microorganisms from agar plates exposed to live infected flies, is described. However, experimental transmission of summer mastitis from sick to healthy heifers by Hydrotaea irritans proved unsuccessful.     

Factors influencing potent antagonistic effects of Escherichia coli and Bacteroides ovatus on Staphylococcus aureus in anaerobic continuous flow cultures

We examined factors related to the potent antagonistic effect of Escherichia coli and Bacteroides ovatus on Staphylococcus aureus in anaerobic continuous flow cultures. In the presence of sugars fermentable by E. coli alone or both E. coli and S. aureus, motile E. coli strains exerted a potent antagonistic effect and S. aureus was expelled from the culture vessel within a few days. Conversely, in the presence of a sugar fermentable by S. aureus alone, the antagonistic effect of E. coli was diminished and S. aureus persisted at ca. 5 x 10(5) cfu/mL. B. ovatus alone exerted only a weak antagonistic effect on S. aureus in any culture conditions; however, when B. ovatus was cocultivated with E. coli and S. aureus, even in the presence of a sugar fermentable by S. aureus but not by E. coli, the potent antagonistic effect was restored. Escherichia coli showed the same level of antagonistic effect either in the presence of acetic acid (ca. 32 mM), propionic acid (4 mM), butyric acid (17 mM) and hydrogen sulfide (5 x 10(-1) mM) or when these metabolic products, except for a small amount of acetic acid (1.2 mM) were not present. In these culture conditions, S. aureus populations were lost at rates much higher than theoretical wash out rates of resting cells. These results indicate the presence of some bactericidal factors other than the volatile fatty acids and hydrogen sulfide. The bactericidal factors were not found in cultures of E. coli heated in boiling water for 10 min and in cell-free culture filtrates. Thus, the bactericidal factors seem to be associated with live E. coli cells. The nature of the bactericidal factors is not clear at present.