Ear Necrosis (swine - fighting)

Ear necrosis in swine is a condition characterized by tissue death affecting the tips and margins of the ear pinnae, resulting from damage caused primarily by ear biting during fighting and aggressive interactions among pigs. This condition represents a significant welfare concern in commercial pig production, occurring most commonly when pigs are mixed into new social groups and must establish dominance hierarchies through physical confrontations. The damage begins with bite wounds that introduce bacteria into ear tissues, leading to vascular compromise, infection, and progressive tissue necrosis that can result in partial or complete loss of ear tip tissue.

Ear necrosis occurs in pig operations worldwide, with prevalence varying considerably based on management practices, housing systems, genetics, and environmental conditions. The condition is most common in recently weaned pigs and in growing-finishing pigs following regrouping events when unfamiliar animals are mixed together. Prevalence studies have reported ear lesion rates ranging from minimal in well-managed operations to over fifty percent in facilities with significant social stress or other predisposing factors. The seasonal pattern of ear necrosis tends to show higher incidence during periods when pigs are housed indoors in close confinement, though outdoor systems are not immune to the problem.

The economic and welfare impact of ear necrosis in swine operations is substantial and multifaceted. Affected pigs experience pain from both the initial bite wounds and the subsequent necrotic process, representing a serious animal welfare concern that has drawn increasing attention from consumers, retailers, and regulatory bodies. Economically, ear necrosis causes reduced growth rates in affected animals, increased medication costs for treatment, additional labor for identifying and managing affected pigs, and potential condemnation of affected carcasses or carcass parts at slaughter. The condition may also indicate broader welfare problems within the operation that could affect overall herd performance.

Early detection and prompt management of ear necrosis are essential for minimizing individual animal suffering and preventing widespread outbreaks within affected groups. When bite wounds are identified early, before significant bacterial invasion and vascular compromise occur, treatment with antimicrobials and anti-inflammatory medications can prevent progression to necrosis. However, once tissue death has begun, the necrotic process will proceed until demarcation occurs, and management focuses on preventing secondary complications and supporting the animal through the healing process. Ultimately, prevention through appropriate management strategies is far more effective than treatment of established cases.

The primary cause of ear necrosis in swine is traumatic injury from ear biting during aggressive interactions between pigs, particularly during the establishment of social hierarchies following mixing of unfamiliar animals. When pigs from different litters or groups are combined, they engage in fighting to establish dominance relationships, with ears being frequent targets of bites due to their accessibility and vulnerability. The bite wounds create portals for bacterial entry, damage blood vessels supplying ear tissues, and initiate inflammatory responses that can progress to tissue necrosis. The ears' relatively poor blood supply and thin tissue structure make them particularly susceptible to necrotic changes following injury.

While not truly hereditary, genetic factors influence susceptibility to ear necrosis through their effects on pig temperament, aggression levels, and ear conformation. Some genetic lines produce pigs with more aggressive tendencies that are more likely to inflict and receive ear bites during social interactions. Ear size and shape may influence vulnerability, with larger, more pendulous ears potentially presenting more accessible targets. Selection for rapid lean growth in commercial genetics may have inadvertently affected behavior and stress responses in ways that influence fighting behavior. However, management and environmental factors generally outweigh genetic factors in determining ear necrosis incidence.

Environmental and management factors play critical roles in ear necrosis development in swine operations. Inadequate space allowances force pigs into closer contact and more frequent confrontations, increasing fighting and ear biting. Poor ventilation leading to elevated ammonia levels and thermal stress increases irritability and aggression. Inadequate feeder and waterer space creates competition that triggers fighting. Barren environments lacking appropriate enrichment materials redirect natural rooting and chewing behaviors toward pen mates' ears. Mixing pigs of disparate sizes or ages creates unfair contests that may result in more severe injuries to smaller individuals.

Risk factors for ear necrosis include the weaning and nursery period when pigs undergo the stress of separation from the sow and introduction to new environments and pen mates, regrouping events at any stage of production, high stocking densities, inadequate environmental controls, nutritional deficiencies that may affect healing or increase irritability, health challenges that reduce general vitality and potentially increase vulnerability to injury and infection, and management practices that necessitate frequent handling or disruption of established groups. The interaction of multiple risk factors often determines whether ear necrosis becomes a significant problem in a given facility or group of pigs.

The pathophysiology of ear necrosis involves the interplay between mechanical injury, bacterial infection, vascular compromise, and the body's inflammatory response. Initial bite wounds damage skin integrity and introduce oral bacteria from the biting pig's mouth into ear tissues. Common bacterial isolates from necrotic lesions include Staphylococcus species, Streptococcus species, and various other opportunistic organisms. The bacterial infection triggers intense inflammation with edema, thrombosis of small blood vessels, and tissue hypoxia. As blood supply is compromised, tissue dies beginning at the ear margins and tips where perfusion is most tenuous. The necrotic tissue eventually sloughs, leaving variably sized defects in the ear pinna.

Early warning signs of developing ear necrosis in swine include fresh bite wounds and scratches on the ears, behavioral indicators of recent fighting such as skin wounds on other body areas, and signs of pain or irritation affecting the ears. Pigs with early ear damage may shake their heads more frequently, hold their ears in abnormal positions, or show reluctance to allow handling of their heads. Observation of actual fighting behavior in the pen indicates ongoing risk for ear injuries. The transition from fresh wounds to necrosis may be subtle initially, with early signs including darkening of ear tip tissue, increasing edema, and development of a demarcation line between viable and compromised tissue.

Common symptoms of ear necrosis in pigs progress from the initial traumatic injury through inflammatory changes to established necrosis and eventual tissue loss. Fresh bite wounds appear as punctures, lacerations, or crush injuries on the ear margins and tips, often with associated bleeding and swelling. As inflammation develops, the affected areas become edematous, warm, and painful. When vascular compromise leads to necrosis, the tissue color changes from normal pink through purple or blue to black as tissue death progresses. The necrotic tissue becomes dry, leathery, and eventually separates from viable tissue along a line of demarcation, ultimately sloughing to leave defects in the ear.

Behavioral changes in pigs with ear necrosis reflect both the pain of the condition and any systemic effects of infection. Affected pigs may go off feed or show reduced appetite, particularly during the acute inflammatory phase. Activity levels may decrease, with affected animals spending more time lying down and less time at feeders. Some pigs become head-shy, avoiding contact and showing defensive reactions when people approach. Social dynamics may shift, with affected animals dropping in the social hierarchy as their reduced vitality makes them less competitive. In severe cases with significant infection, systemic illness may cause more generalized depression and lethargy.

Physical signs of ear necrosis evolve as the condition progresses through stages. In the inflammatory stage, ears show swelling, reddening, increased warmth, and obvious pain response to manipulation. Discharge from wounds may be serous initially, becoming purulent if bacterial infection intensifies. As necrosis develops, affected tissue changes color through the purple-blue-black spectrum, becomes cold as blood flow ceases, and loses sensation. A distinct line of demarcation develops between dead and viable tissue. Eventually, the necrotic tissue dries, mummifies, and separates, leaving partial loss of ear tip tissue. Scarring of remaining ear tissue produces permanent deformity.

Symptom progression in ear necrosis follows a predictable timeline once vascular compromise has occurred. Fresh bite wounds may develop within minutes to hours of a fighting episode. Inflammatory changes including swelling and color change begin within hours and progress over one to three days. Frank necrosis with tissue death becomes evident by three to seven days post-injury in cases with significant vascular damage. The demarcation between viable and non-viable tissue stabilizes over one to two weeks. Sloughing of necrotic tissue occurs over two to four weeks, with healing of the remaining viable ear tissue continuing for several additional weeks. The entire process from initial injury to healed residual ear may span four to eight weeks.

Emergency symptoms requiring immediate intervention in cases of ear necrosis include signs of severe secondary infection with systemic illness such as high fever, severe depression, complete anorexia, or sepsis. Extensive tissue involvement affecting areas beyond the ears or suggesting aggressive spreading infection warrants urgent veterinary attention. Hemorrhage from damaged blood vessels that fails to stop with simple pressure requires intervention. Pigs showing extreme pain, inability to eat or drink, or rapid deterioration need immediate evaluation and care. While most ear necrosis cases can be managed without emergency intervention, these serious complications require prompt aggressive treatment.

Clinical examination for ear necrosis in swine is typically straightforward, as the condition produces characteristic visible lesions. Examination begins with observation of behavior and ear appearance from a distance before moving pigs for closer inspection. The examiner notes any head shaking, ear scratching, or abnormal ear carriage. Physical examination of both ears assesses the extent and stage of lesions, comparing affected areas to unaffected tissue. The character of any wounds, the presence and color of any necrotic tissue, and the development of demarcation lines are documented. Palpation assesses tissue temperature, consistency, and pain response, distinguishing between inflamed viable tissue and insensate necrotic areas.

Diagnostic tests for ear necrosis are generally unnecessary for diagnosis but may be helpful for guiding treatment decisions and investigating underlying factors in severe outbreaks. Bacterial culture and sensitivity testing of wound or lesion samples can identify specific pathogens and guide antimicrobial selection when treatment failure occurs or resistant organisms are suspected. Complete blood counts may reveal leukocytosis consistent with bacterial infection or anemia in cases with significant blood loss. Serology or PCR testing for specific swine pathogens may be warranted if underlying infectious disease is suspected as a predisposing factor. In severe outbreaks, necropsy examination of affected pigs can provide comprehensive assessment of tissue changes and contributing factors.

Differential diagnosis for ear lesions in pigs includes several conditions that must be distinguished from fighting-related ear necrosis. Ear mite infestation causes crusty lesions and ear irritation but without the bite wound pattern and tissue necrosis. Sunburn in outdoor pigs can damage ear tips but follows sun exposure patterns rather than bite distribution. Vesicular diseases including foreign animal diseases like foot-and-mouth disease can cause ear lesions and must be ruled out through appropriate testing when clinical signs are compatible. Frostbite in cold weather causes necrosis of ear tips with a different history and seasonal pattern. Ergot toxicosis from contaminated feed causes peripheral tissue necrosis including ear tips. Swine erysipelas and other systemic infections can cause ear discoloration and necrosis.

Herd-level diagnostic assessment is essential when ear necrosis affects multiple pigs or reaches significant prevalence within a group. Systematic evaluation of management factors should assess stocking density, feeder and waterer space, environmental conditions, and enrichment provision. Review of mixing and grouping practices identifies high-risk events. Examination of nutritional adequacy investigates potential deficiencies affecting healing or behavior. Assessment of overall herd health identifies underlying disease challenges that may predispose to ear necrosis through general debilitation or specific effects on circulation or immunity. Analysis of when and where ear necrosis cases occur guides targeted prevention strategies.

Emergency and immediate treatment of ear necrosis focuses on managing pain, controlling infection, and preventing disease progression in affected individuals while addressing the group-level factors driving the outbreak. Individual pigs with fresh ear wounds or early necrotic changes should be treated promptly with systemic antimicrobials to control bacterial infection and prevent spread of tissue damage. Injectable nonsteroidal anti-inflammatory drugs provide analgesia and reduce inflammation, helping maintain feed intake and comfort. Severely affected individuals may need to be removed from the group and housed separately to prevent further injury and allow healing without social stress.

Medical management of established ear necrosis centers on antimicrobial therapy to control infection, pain management, and supportive care. Systemic antimicrobials effective against the gram-positive organisms commonly isolated from ear lesions should be administered, with selection guided by culture results if available. Common choices include penicillins, cephalosporins, or lincosamides, with strict attention to withdrawal times for food-producing animals. Treatment duration typically extends for five to seven days or until infection is clearly controlled. Anti-inflammatory therapy continued throughout the acute phase improves comfort and supports appetite.

Topical treatment of ear necrosis lesions may supplement systemic therapy but is generally secondary in importance. Gentle cleaning of wounds with dilute antiseptic solutions removes debris and reduces bacterial load. Topical antimicrobial sprays or ointments can provide local antibacterial activity, though penetration into necrotic tissue is limited. Fly repellent applications prevent myiasis in outdoor or warm-weather conditions. Once necrotic tissue has clearly demarcated and begun to slough, debridement of loose dead tissue may speed healing, though aggressive debridement before demarcation is complete risks extending tissue loss.

Supportive care for pigs with ear necrosis includes environmental and nutritional management alongside medical treatment. Affected pigs should be housed in clean, dry conditions with adequate space to avoid further trauma. Access to feed and water should be easy, without competition that might discourage eating. Good nutrition supports immune function and tissue healing. Protection from environmental extremes reduces stress during recovery. Pigs healing from ear necrosis should be monitored daily to assess response to treatment, identify any complications, and adjust management as needed.

Group-level intervention is essential because treating individual affected pigs does not address the underlying causes driving ear necrosis outbreaks. Management changes to reduce fighting and ear biting should be implemented immediately when ear necrosis is identified. Providing additional space, if possible, reduces confrontations. Adding environmental enrichment such as chains, ropes, or other manipulable materials redirects oral behaviors away from pen mates. Ensuring adequate feeder and waterer access eliminates competition as a fighting trigger. Addressing environmental stressors including temperature extremes, poor air quality, and inadequate lighting reduces irritability. These group-level interventions are more important than individual treatment for controlling ear necrosis outbreaks.

Treatment decisions for ear necrosis in commercial swine operations must balance individual animal welfare against practical and economic considerations. All affected pigs deserve appropriate pain management and basic supportive care regardless of economic analysis. For mildly affected animals, topical treatment and management changes may be sufficient. Moderate cases benefit from systemic antimicrobial and anti-inflammatory therapy. Severely affected pigs may require more intensive individual care or, if prognosis for recovery is poor, humane euthanasia may be the most appropriate welfare choice. Withdrawal times for all medications must be observed for food-producing animals, potentially affecting marketing timing.

Recovery timeline for ear necrosis in swine varies based on the extent of tissue damage, the effectiveness of treatment, and the resolution of underlying risk factors. The acute inflammatory phase typically resolves within one to two weeks with appropriate antimicrobial and anti-inflammatory therapy. Necrotic tissue completes demarcation and begins sloughing over two to four weeks from the initial injury. Complete healing of the remaining viable ear tissue may require an additional two to four weeks following tissue loss. The total timeline from initial injury to healed residual ear typically spans four to eight weeks, though minor lesions may resolve more quickly while severe cases take longer.

Post-treatment care and monitoring for pigs recovering from ear necrosis includes ongoing observation of healing progress, completion of prescribed treatments, and continued attention to underlying risk factors. Affected ears should be examined regularly to assess healing, identify any complications such as secondary infection or delayed healing, and determine when active treatment can be discontinued. Pigs should be monitored for return of normal behavior, appetite, and growth. Protection from further ear trauma during the healing period is essential, which may require continued separation from aggressive pen mates or implementation of effective group-level management changes.

Prognosis for pigs with ear necrosis is generally good for survival and recovery of function, though permanent ear deformity is common. Most affected pigs recover successfully with appropriate treatment and management, returning to normal growth and performance once healing is complete. The extent of permanent ear tissue loss varies from minimal notching to significant shortening or complete loss of ear tips. While ear deformity is cosmetically undesirable, it does not impair the pig's function or productivity once healed. Pigs that develop severe secondary infection, systemic illness, or extensive tissue necrosis have more guarded prognoses and may require euthanasia in severe cases.

Return to production considerations for pigs recovered from ear necrosis include ensuring complete healing before exposure to stressful situations, observing medication withdrawal times, and addressing any residual ear changes that might affect identification or market acceptance. Pigs should be fully healed before transport or exposure to additional social stress. All antimicrobial and anti-inflammatory treatments must have completed appropriate withdrawal periods before slaughter. Ear tags or other ear-based identification may need to be relocated if original placement sites are damaged. Market pigs with significant ear deformity should be evaluated for any impact on acceptance at slaughter facilities.

Vaccination plays no role in direct prevention of ear necrosis, as this condition results from traumatic injury and behavioral factors rather than specific infectious agents. However, maintaining overall herd health through comprehensive vaccination programs reduces disease challenges that might debilitate pigs and increase their vulnerability to injury or their aggressive behavior. Vaccination against common swine pathogens including porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, and other endemic diseases reduces health stressors that can predispose to ear necrosis through effects on pig vitality and behavior.

Biosecurity considerations for ear necrosis prevention relate primarily to disease prevention rather than direct ear necrosis prevention, as the condition is not transmissible between animals in the usual sense. Maintaining high health status through biosecurity measures reduces disease challenges that may predispose to ear biting behavior or impair healing. Controlling endemic diseases allows pigs to direct energy toward growth rather than immune responses. Good biosecurity practices also support overall animal welfare and performance, indirectly reducing ear necrosis risk.

Nutritional prevention strategies for ear necrosis focus on meeting all nutrient requirements to support normal behavior, immune function, and tissue healing. Adequate protein and amino acid intake supports growth and tissue repair. Mineral nutrition, particularly zinc and copper, is important for skin health and wound healing. Some research suggests that dietary salt levels and electrolyte balance may influence redirected oral behaviors toward pen mates. Fiber inclusion in diets may help satisfy foraging drives and reduce ear biting. Feed particle size and diet texture have been investigated as factors affecting stomach health and potentially behavior. Ensuring consistent feed availability eliminates nutritional stress that might increase aggression.

Management practices represent the most important interventions for ear necrosis prevention in swine operations. Avoiding mixing of unfamiliar pigs prevents the fighting that occurs during social hierarchy establishment. When mixing is unavoidable, strategies to reduce fighting intensity include mixing at night, providing distractions, and using masking odors. Providing adequate space per pig reduces confrontations and allows subordinate animals to escape aggressors. Ensuring abundant feeder and waterer access eliminates competition. Environmental enrichment with manipulable materials such as chains, ropes, balls, straw, or wood provides alternative outlets for oral behaviors. Maintaining optimal environmental conditions including temperature, humidity, and air quality reduces stress and irritability.

Quarantine principles apply to ear necrosis prevention primarily through their role in controlled introductions rather than infectious disease prevention. Gradual introduction of new pigs through adjacent pens with limited contact before full mixing allows some habituation and reduces fighting intensity when pigs are combined. Mixing pigs of similar size and age creates fairer contests with less severe outcomes. Timing mixing events to occur during cooler parts of the day or in the evening when pigs are less active may reduce fighting. Supervision during initial mixing allows intervention if fighting becomes severe. These controlled introduction practices substantially reduce ear necrosis incidence in operations where mixing is necessary.

Daily management and monitoring for ear necrosis prevention requires consistent attention to pig behavior and ear health throughout all production phases. Personnel observing pigs during feeding, moving, or routine care should watch for fresh ear wounds, signs of fighting, and early indicators of developing necrosis. Any observed fighting should prompt evaluation of management factors that might be triggering aggressive behavior. Early identification of pigs with ear damage allows prompt treatment before necrosis develops. Daily observation also identifies environmental or management problems that increase ear biting risk, enabling timely corrections. Documentation of ear lesion observations supports tracking of problem severity and evaluation of intervention effectiveness.

Housing and environmental management are critical determinants of ear necrosis risk in swine facilities. Space allowances should meet or exceed recommendations for the age and size of pigs, with greater space helping reduce fighting and allowing subordinate animals to escape aggressors. Flooring should provide secure footing without abrasive surfaces that might exacerbate ear wounds. Environmental controls should maintain temperatures within the thermoneutral zone for pigs of each age, as thermal stress increases irritability and fighting. Ventilation should maintain good air quality with low ammonia and dust levels. Lighting programs should provide appropriate photoperiods with adequate intensity for normal behavior.

Enrichment provision represents one of the most effective management interventions for reducing ear biting and ear necrosis in swine. Manipulable materials that pigs can chew, root, and explore provide appropriate outlets for oral behaviors that might otherwise be directed toward pen mates. Effective enrichment materials include chains or ropes suspended at pig height, rubber or plastic balls or toys, straw or hay when management allows, and pieces of natural wood. Enrichment should be provided in sufficient quantity that all pigs can access materials without competition. Materials should be novel and interesting, with periodic rotation to maintain engagement. Research consistently demonstrates reduced ear and tail biting in groups with effective enrichment compared to barren environments.

Record keeping and monitoring systems for ear necrosis support both prevention and outbreak management. Records should document ear lesion prevalence by group, pen, or building to identify high-risk areas. Tracking ear necrosis over time reveals seasonal patterns, relationships to specific events such as mixing, and response to management changes. Treatment records for affected individuals ensure regulatory compliance for food-producing animals and provide outcome data. Aggregate analysis of records identifies risk factors specific to the operation and guides targeted prevention strategies. Benchmarking against industry standards helps evaluate whether ear necrosis prevalence represents normal background levels or indicates problems requiring intervention.

Economic considerations in ear necrosis management support investment in prevention strategies. Direct costs of ear necrosis include treatment medications, labor for identifying and treating affected pigs, reduced growth performance in affected animals, and potential carcass condemnations or downgrades at slaughter. Indirect costs include broader welfare implications that may affect market access, consumer acceptance, and regulatory standing. Prevention costs include space and facility investments, enrichment materials, and management attention. Economic analysis consistently shows that prevention through appropriate housing, management, and enrichment is more cost-effective than treating ear necrosis outbreaks. Producer investments in ear necrosis prevention also demonstrate commitment to animal welfare that supports market relationships.

High-risk breeds and genetic lines for ear necrosis include those with more aggressive temperaments that engage in more frequent or more intense fighting when establishing social hierarchies. Some genetic lines selected intensively for production traits may have inadvertently acquired behavioral characteristics that increase aggression or reduce stress tolerance. Ear conformation may influence susceptibility, with larger ears potentially presenting more accessible targets, though research on this relationship is limited. Crossbred pigs may show heterosis for vigor and activity that could translate to more intense social interactions. However, management and environmental factors typically overwhelm genetic effects in determining ear necrosis incidence, meaning that appropriate management can control ear necrosis regardless of genetics.

Production type considerations significantly influence ear necrosis risk in swine operations. Intensive confinement systems that house large numbers of pigs in limited space see higher ear necrosis rates than extensive or outdoor systems where space limitations are less constraining. The weaner and nursery phases present particular risk due to the stress of weaning combined with mixing of pigs from different litters. Growing-finishing facilities that receive pigs from multiple sources and mix them upon arrival experience high ear necrosis risk during the post-arrival period. Breeding herds with stable social groups typically see less ear biting than production facilities with frequent mixing events. The system's design for enrichment provision, space allowance, and environmental control strongly influences ear necrosis prevalence.

Genetic selection and testing approaches for reducing ear necrosis susceptibility remain largely in the research phase rather than routine commercial application. Some genetic improvement programs include temperament or behavior assessments that might indirectly select for reduced aggression and fighting. Selection for stress resistance and adaptability could reduce the behavioral responses that lead to ear biting. Genomic studies have identified potential markers associated with tail biting behavior that might also relate to ear biting, though practical implementation is not yet widespread. Most genetic companies focus selection on production traits rather than behavior, leaving management as the primary tool for ear necrosis control in commercial operations.

Commonly co-occurring conditions with ear necrosis in swine include tail biting and tail necrosis, which share many of the same predisposing factors and often occur together in affected groups. Skin wounds and abrasions from fighting may be present on body areas beyond the ears. Secondary bacterial infections of ear lesions may spread to cause more generalized illness in severely affected pigs. Stress-related conditions including gastric ulceration may be elevated in herds with significant ear necrosis problems. Other welfare-compromising conditions such as lameness, respiratory disease, and poor body condition may be more prevalent in operations where management factors predispose to ear necrosis. The presence of ear necrosis often indicates broader welfare challenges requiring comprehensive assessment and intervention.

Conditions with similar symptoms that must be differentiated from fighting-related ear necrosis include other causes of ear tissue damage and necrosis. Ear mite infestation causes ear irritation and crusty lesions but not the necrosis pattern seen with fighting injuries. Frostbite in cold weather causes ear tip necrosis but follows cold exposure rather than fighting. Sunburn in outdoor pigs damages ear tips exposed to solar radiation. Ergot toxicosis from contaminated feed causes peripheral necrosis including ear tips. Vesicular diseases causing ear lesions must be ruled out through appropriate diagnostic testing. Bacterial ear infections may complicate or be confused with fighting injuries. Swine erysipelas can cause ear discoloration and necrosis through a different pathophysiology.

Complications and sequelae of ear necrosis include secondary bacterial infection that may become severe, potentially leading to sepsis in serious cases. Aural hematoma may develop secondary to head shaking and ear trauma associated with the condition. Permanent ear deformity results from tissue loss, affecting appearance and potentially complicating ear-based identification methods. The experience of ear necrosis may affect pig behavior, potentially leading to changes in social position, feeding patterns, or stress responses. Chronic ear changes predispose to secondary infections or additional injury. In herds with endemic ear necrosis, cumulative welfare impacts affect overall herd wellbeing and productivity. The presence of ear necrosis may indicate systemic management problems requiring comprehensive evaluation and improvement.