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.     

Procedures and surgeries of the teat.

Injuries to the end of the teat are frequent and frustrating to treat. Treatment of these injuries evolved from being aggressive using teat knives to a more conservative approach employing rest nonreactive teat inserts. The process of milking seems simple, but it involves fine-tuned mechanics. Teat fibrosis, even when small, has a disastrous effect on the production life of an animal. There is no place for error; any surgical intervention should be precise and aim for perfection. Medical imaging techniques and minimally invasive surgery help the surgeon to make the best decision. Finally, more investigation is needed to treat varicose veins to understand the origin and develop better treatment. Teat injuries have drawn more attention more recently. Surgical interventions are better planned, and blind treatment with unsuitable teat knives is avoided. Treatment of superficial of full-thickness teat lacerations does not require a high level of anatomic or surgical knowledge, although basic surgical principles should be applied. Hemostasis, delicate débridgement and tissue handling, and appropriate suture materials and patterns are key to success. Appropriate sedation, anesthesia, and analgesia are essential to achieve this goal and should never be neglected.     

猪乳头数性状QTL研究进展

乳头数是种猪繁殖性能选育的重要指标之一。母猪乳头数与其繁殖性能有着较强的相关性,乳头数越多,则窝产仔数越多。因此,在选择种公猪及母猪时要着重考虑乳头数,对乳头数性状施予较高的选择强度,选育出乳头数较多的种猪,以满足高产仔数的需要。论文综述了猪乳头的形成和调控机制,猪乳头数性状QTL定位方法及其研究进展,旨在深入理解猪乳头数性状在猪繁殖性能中的重要作用,为种猪选育提供参考。     

Sampling of the bovine teat for studies of defence mechanisms and inflammatory reactions based on a surgical procedure separating the teat and udder cisterns

A surgical procedure to separate the teat and udder cisterns in the udder quarter was described. The sampling method used and its influence on the somatic cell count and bacteriological status of the teat samples were determined. The surgical procedure resulted in complete separation of the teat cistern from the udder cistern in nine out of fourteen teats in six cows. An increase in SCC was seen in one of nine teats during the sampling period of 4 to 8 days. Coagulase-negative staphylococci were isolated in samples from three of six teats at the end of the sampling period. The described methods could be of considerable importance in future studies of inflammatory reactions and defence mechanisms in the bovine teat.     

The prophylactic effect of a teat sealer on bovine mastitis during the dry period and the following lactation

AIM: To determine the prophylactic efficacy of a teat sealer, administered at drying off, in reducing new intramammary infections in the dry period and the following lactation. METHODS: A total of 528 cows with late lactation somatic cell counts <2 00,000 cells/ml was identified in three commercial herds. Of these, bacteriological examination showed 482 cows were uninfected in all four quarters and 46 were infected in only one quarter. At drying off, uninfected quarters were randomly allocated to the following treatments: no infusion (negative controls), infusion with a bismuth subnitrate based teat sealer, infusion with teat sealer + antibiotic, or infusion with a cephalonium-based dry cow antibiotic (positive control). New infections were identified during the dry period by periodic udder palpations and at calving by bacteriological culture. RESULTS: All three infused treatments reduced the incidence of new intramammary infections due to Streptococcus uberis, both during the dry period and at calving, by about 90% (p <0.01). The majority of the infections were due to Streptococcus uberis. For all treatments, a 50% lower incidence of clinical mastitis over the first 5 months of the ensuing lactation was reported by farmers. X-ray imaging of 19 teats showed that the teat sealer material was retained, at least in part, in the lower teat sinus over about 100 days of the dry period. CONCLUSIONS: Closure of the teat canal from day one of the dry period as achieved by the teat sealer was as effective in reducing new dry period infections as the infusion of a long-acting dry cow antibiotic formulation. The lower incidence of new infections in the ensuing lactation among the infused quarters implies that fewer subclinical infections persisted from the dry period. Use of teat sealers at drying off appears to offer the same prophylactic efficacy as the dry cow antibiotic approach.     

Resistance mechanisms of the bovine udder: new implications for mastitis control at the teat end

Investigations on bovine teat-end defenses and their role in mastitis control were reviewed. Alteration of teat canal keratin by method of intramammary drug infusion through the teat canal influenced the number of new infections. At the beginning of the nonlactating period, 2 methods of administering antibiotic were studied: full insertion of treatment syringe cannulas into teat cisterns and expelling contents and partial insertion of cannulas into the distal 2 to 3 mm of teat canals and slowly infusing contents. Partial cannula insertion reduced new infections by 50% and is an easily adopted management tool to reduce prevalence of mastitis. Intramammary devices used during lactation and the nonlactating period increased leukocyte concentrations in mammary secretions. An abraded polyethylene coil device reduced clinical mastitis and increased milk yield. Staphylococci colonize teat canal keratin and lacteal secretions of dairy heifers as early as 9 months of age, leading to intramammary infection at time of calving and persisting into lactation. Subsequent somatic cell counts are associated with milk production losses. Previously, such infections were shown to be associated only with older, mature animals.     

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.     

Milk-flow, ultrasonographic, theloscopic, and histopathological characteristics of the teat in cows with toxic mastitis

The milk-flow, imaging, and histopathological characteristics of the teat in five cows with toxic mastitis were investigated. Teats were grouped into type I (without gross and histopathological abnormality), type II (no abnormal gross findings, but with histopathological abnormality), and type III (with gross and histopathological abnormality). Normal teats from six cows served as controls. Type II and III teats had lower milk-flow, compared with the controls. Ultrasonography revealed no abnormal findings, except for irregular mucosal surface in type II teats and absence of hyperechoic line along the teat canal in type III teats. The theloscopic findings varied from normal to mucosal abnormalities in type II and III teats. Histopathology demonstrated epithelial changes, congestion, hemorrhage, edema, cellular infiltration, and elastic fiber degradation in type II and III teats, with the type III teats showing severe changes. Toxic mastitis was characterized by impaired milk-flow and various degrees of imaging and histopathological abnormality.     

Influence of milking technique and lactation on the bovine teat by means of ultrasonographic examination

The teats of Brown Swiss and Austrian Simmental cows, divided into two groups, one milked by means of an automatic milking system, the other using a conventional milking parlour, were examined monthly by ultrasonography. Aim of the study was to compare the effects of two different milking machines upon the structures of the bovine teat canal and wall by ultrasonography and thereby evaluate ultrasonography as a research tool for visualisation of different influences on the bovine teat. Length and thickness of the teat canal and teat wall thickness were measured and analysed. During lactation, teat canal length and thickness increased in both groups, teat canal length decreased in conventional milked cows at the end of lactation. Shorter and narrower teat canals were observed in automatic milked cows. Differences between the groups in teat canal length and thickness were determined in early lactation. During lactation teat wall thickness showed a slight increase. Automatic milked cows displayed thinner teat walls than cows milked in the milking parlour. Teat morphology was influenced by the number and duration of lactations, milk yield, quarter of the udder and time and date of examination. It was concluded that the effect of the two different milking machines caused significant differences in bovine teat morphology and that ultrasonography proved to be an appropriate method for visualising influences of the milking technique on the bovine teat.     

猪翻乳头的解剖组织学特征的研究与探讨

通过对正常乳头，翻乳头，副乳头及其乳房的组织样本进行解剖学观察，对照，发现正常乳头由乳基，乳头本组成；翻乳头由乳基，不明显的乳头体组成；副乳头只有小突起。对各类乳腺做成切片观察，对照，发现正常乳头和翻乳头均有完整的乳腺，乳管，副乳头的乳腺，乳管不发达，且很稀少。     

副乳头对奶牛生产性能的影响及其相关基因LGR5的遗传表达分析

试验旨在探究副乳头（SNT）对奶牛产奶性能的影响及乳腺发育相关基因LGR5与副乳头发生的关系。收集325头有副乳头奶牛及同年出生的737头无副乳头奶牛的产奶性能数据,比较有、无副乳头奶牛间的产奶性能差异;利用实时荧光定量PCR技术检测有、无副乳头奶牛LGR5基因的表达差异,通过直接测序法测定有、无副乳头奶牛的LGR5基因序列,寻找该基因上的遗传突变。结果表明,无副乳头奶牛的日产奶量、高峰奶量及泌乳持续力等产奶性能均优于有副乳头奶牛,但未达到统计学显著水平;LGR5基因在有副乳头奶牛中的表达量显著高于无副乳头奶牛（P<0.05）;在LGR5基因第1内含子中检测到3个SNPs：rs42849472、rs42849471和rs42849470,有副乳头奶牛中3个SNPs的AA基因型频率均极显著高于无副乳头奶牛（P<0.01）。结果提示,LGR5基因可能与奶牛副乳头发生有关,可作为有效的候选基因。     

Effects of quarter individual and conventional milking systems on teat condition

An on-farm experiment was performed to investigate the effects of two milking systems on teat condition. An auto-tandem milking parlor made by GEA^® with a conventional milking cluster (CON) and a single tube milking system called MultiLactor^® (MULTI) from Siliconform GmbH were tested. For both milking system, in total 73 animals were milked over a period of seven months. To assess the effect of milking on teat condition, each teat was scored according to teat-condition evaluation systems. To evaluate teat condition, the teat color, ring formation at the teat base and formation of teat hyperkeratosis were assessed. The evaluation was conducted once a month after milking. The collected data were then statistically analyzed with generalized linear mixed models. The only differences found between the two milking systems occurred with respect to their effect on teat color. MULTI showed significantly better scores compared to CON. There were no significant differences between the milking systems with regard to teat-end hyperkeratosis and ring formation at the teat base.     

Evaluation of three-dimensional ultrasonography of the bovine mammary gland

OBJECTIVE: To evaluate 3-dimensional (3-D) ultrasonography of the bovine mammary gland, particularly of the teat. ANIMALS: 6 lactating cows. PROCEDURES: Clinical and ultrasonographic examinations of mammary glands of each cow were performed. Teats were removed from a slaughtered cow and examined via ultrasonography. All scans were performed by use of a sensorless standard transducer (8.5 to 10 MHz linear array). The 2-dimensional data acquired were downloaded to an off-line system, and software was used to digitize each image and produce a 3-D block of digitized information. The selected anatomic area was displayed as a 3-D volume cube. RESULTS: Good-quality, 3-D views of the entire mammary gland were acquired by obtaining sections through the glandular parenchyma, gland cistern, teat cistern, and teat canal. CONCLUSIONS AND CLINICAL RELEVANCE: 3-D ultrasonography allows perspective images of the mammary gland to be obtained. Many scanners routinely used in veterinary practice have the resolution required to produce satisfactory images, and the cost of refitting a standard ultrasonographic unit with 3-D software is affordable; however, the cost of a volume transducer with a positioning system and mechanical sweep strategy may be prohibitive. Three-dimensional ultrasonography is a new imaging technique that has promising applications in many fields of veterinary medicine.     

Effects of different teat inserts on wound healing of experimentally incised streak canal in non-lactating cattle

The recurrence of reduced milk flow is a common sequela after placement of teat inserts in the streak canal as a treatment for teat injury. We evaluated the effects of three types of commercial teat inserts on wound healing. Thirty-two normal streak canals of eight cows were incised longitudinally using a teat knife. Then, a wax-bougie, silicone self-retaining cannula, and catgut teat dilator were placed in each cow for 7 days. No insert was placed on the remaining teat as a control. Histopathological examination revealed that granulation polyps with squamous metaplasia developed in the area around the rosette of Furstenberg in most teats in which silicone cannulas and catgut teat dilators were placed, whereas the controls and the teats with wax-bougies healed with less tissue reaction. This study suggests that the placement of irritating inserts, such as a silicone cannula and catgut teat dilator, interfere with wound healing.     

Effect of pre-milking teat preparation procedures on the microbial count on teats prior to cluster application

A study was carried out to investigate the effect of six pre-milking teat preparation procedures on lowering the staphylococal, streptococcal and coliform microbial count on teat skin prior to cluster application. The teat preparations included 'Iodine', 'Chlorhexidine' teat foam, 'Washing and drying' with paper, 'No preparation', 'Chlorine' teat foam, and disinfectant 'Wipes'. Teat preparations were applied for five days to 10 cows for each treatment during two herd management periods (indoors and outdoors). Teats were swabbed on day four and five before teat preparation and repeated after teat preparation. The swabs were plated on three selective agars: Baird Parker (Staphylococcus spp.), Edwards (Streptococcus spp.), and MacConkey (coliform). Following incubation, microbial counts for each pathogen type were manually counted and assigned to one of six categories depending on the microbial counts measured. The results were analysed by logistic regression using SAS 28. The main analysis was conducted on binary improvement scores for the swabbing outcomes. There were no differences for staphylococcal, streptococcal and coliform bacterial counts between treatments, measured 'before' teat preparation. Treatments containing 'Chlorhexidine' teat foam (OR = 4.46) and 'Wipes' (OR = 4.46) resulted in a significant reduction (P < 0.01) in the staphylococcal count on teats compared to 'Washing and drying' or 'No preparation'. 'Chlorine' teat foam (OR = 3.45) and 'Wipes' (3.45) had the highest probability (P < 0.01) of reducing streptococcal counts compared to 'Washing and drying' or 'No preparation'. There was no statistical difference between any of the disinfectant treatments applied in reducing coliforms. Thus, the use of some disinfectant products for pre-milking teat preparation can have beneficial effects on reducing the levels of staphylococcal and streptococcal pathogens on teat skin.     

Studies of endotoxin-induced neutrophil migration in bovine teat tissues, using indium-111-labeled neutrophils and biopsies.

Neutrophil migration through bovine teat tissues into the teat cistern, after endotoxin infusion into the teat cistern, was determined in vivo by 2 experimental procedures, indium-111 labeling of blood neutrophils, and obtaining multiple biopsy specimens from the teat cistern tissues. In both experiments, the number of leukocytes in the teat cistern flushing samples was continuously measured. A lag phase of approximately 1 hour was required between endotoxin infusion into the teat cistern and the first observed neutrophil accumulation in the teat tissues. The rate of neutrophil accumulation in the teat tissues was highest between postinfusion (PI) hours 1 and 2, and the accumulation process ceased after PI hour 3. Neutrophils migrated toward the epithelium, and intraepithelial neutrophils were observed beginning approximately 2 hours after infusion, which coincided with the first influx of cells into the teat cistern. The cell influx into the teat cistern increased continuously up to PI hour 3, peaked between PI hours 3 and 5, and was close to preinfusion value at PI hour 22. Use of indium-111-labeled neutrophils in the study of the inflammatory process provides a reliable noninvasive method to quantify cell migration in vivo. Use of biopsies allows quantification of the number of cells in different tissue areas, but has the disadvantage of being invasive. These 2 procedures complement each other, and could be of use in future studies of the local inflammatory process.     

The association between teat end hyperkeratosis and teat canal microbial load in lactating dairy cattle

Most pathogens that cause bovine mastitis invade the udder lumen through the teat canal. Amino acids and intercellular lipids may support microbial colonisation of the teat canal epithelium by pathogenic microorganisms. The aim of this study was to investigate the association between teat end hyperkeratosis, which is induced by machine milking, and teat canal microbial load. Contralateral teats, which differed in teat end hyperkeratosis scores, were identified in a split-udder experiment. The teat canal's microbial load was evaluated using the wet and dry swab technique. Staphylococcus (S.) aureus, Streptococcus (Sc.) uberis, Escherichia (E.) coli and other coliforms were detected by agar plate cultures. The positive detection of E. coli and the log(10)-transformed E. coli load of a teat canal were significantly associated with the teat end hyperkeratosis score (P<0.05). There were significant differences with respect to positive findings for E. coli, as well as the microbial load of E. coli and Sc. uberis, between the less-calloused and the more-calloused teat of a pair. For S. aureus, no significant associations between hyperkeratosis score and teat canal microbial load were detected. In general, a teat with a highly calloused teat end had an increased teat canal microbial load compared with the contralateral teat, characterised by a lower callosity. The results of the present study indicate that the environmental pathogen load is associated with teat end hyperkeratosis. Further research is needed to identify factors that may affect teat canal microbial load in lactating dairy cattle.     

Teat tip reconstruction by supernumerary teat autotransplantation in cattle

OBJECTIVE: Evaluation of use of a supernumerary teat as a pedicle graft to repair experimental teat tip damage in cattle. STUDY DESIGN: Experimental study. ANIMALS: Mature, non-gravid hybrid cows with > or =1 supernumerary teat. METHODS: The main teat and adjacent supernumerary teat were examined for patency by ultrasound with a 8 MHz linear array transducer. The tip of the main teat was resected at the junction of cistern and canal. The supernumerary teat was partially resected semi-circumferentially at the cranial aspect of the base to maintain vascular supply and transplanted by end-to-end anastomosis. The pedicle of the supernumerary teat graft was amputated in stages starting at 14 days, again at 16 days and separated at 18 days. Reconstructed teat patency was evaluated at intervals by ultrasonography and confirmed at 50 days by histopathology. Repeated measures ANOVA was used to compare the measurements of luminal diameter between days; significance was set at P<.05. RESULTS: All reconstructed teats were patent. Decreased luminal diameters were detected at 25, 32, 39, and 46 days by ultrasonography. On histopathology, granulation and epithelial (mucosal) proliferation contributed to luminal reduction. CONCLUSIONS: In this experimental model of an acute damage to a teat tip, supernumerary teat grafting was successfully used to restore teat anatomy. CLINICAL RELEVANCE: Supernumerary teat pedicle grafting may be considered as a salvage technique for reconstruction of a damaged bovine teat in cows that have an adjacent patent supernumerary teat. Function of the reconstructed teat in a lactating cow remains unknown.     

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.     

Obliteration of all teat cisterns in a cow

A rare case of agalactia in a 7 year old cow is described. At the start of the 5th lactation all the teat cisterns were obliterated. Post mortem x-ray examination, with bariumsulfate contrast deposition in the glandular--and the teat cisterns, showed horizontal membranes in the proximal half of the teat cisterns. The membranes were 13--20 mm thick and consisted of fibrous tissue. Glandular tissue, distal parts of teat cisterns and teat canals were normal, and there was no sign of mastitis Obliteration of the teat cisterns, which had developed during the dry period, between the 4th and 5th lactation periods, were assumed to be a result of improper machine milking. The importance of overmilking is discussed.