# Dairy Cow Displaced Abomasum Risk Factors ## Key Takeaways - Inadequate dry matter intake during the transition period (three weeks prepartum to three weeks postpartum) is the most consistent predisposing factor for displaced abomasum (DA), exacerbated by negative energy balance and hypocalcemia. - Hyperketonemia, indicated by elevated nonesterified fatty acids (NEFA) prepartum and beta-hydroxybutyrate (BHBA) postpartum, significantly increases DA risk by reducing appetite and abomasal motility. - Housing conditions that limit voluntary movement, such as overcrowding and poor stall design, reduce feeding time and rumination, contributing to abomasal atony and gas accumulation. - Early clinical assessment, including monitoring feed intake, rumen fill, and manure consistency, is critical; a persistent drop in feed intake beyond 24 hours or elevated ketone bodies warrant veterinary consultation. - Metabolic disturbances like hypocalcemia, indicated by low plasma calcium at parturition, impair gastrointestinal smooth muscle function, directly impacting abomasal tone and motility. - Systematic record-keeping of DA events, body condition scores, and metabolic test results is essential for identifying herd-level risk factors and evaluating the efficacy of management interventions. --- Displaced abomasum (DA) in dairy cows results from a combination of rumen hypomotility, abomasal atony, and gas accumulation that forces the organ to migrate left or right. The most consistent predisposing factor is inadequate dry matter intake during the transition period, compounded by negative energy balance, hypocalcemia, and housing conditions that limit voluntary movement or feeding behavior. Effective management requires close observation of feedbunk behavior, group-level intake trends, stocking density, and early detection of clinical signs such as decreased rumen fill or mild abdominal distension. ## At a Glance The table below outlines the primary risk factor domains addressed in this article alongside their corresponding management focus. These categories are not exhaustive but represent the areas where producer action can most directly influence DA incidence. | Risk Factor Domain | Management Focus | |-------------------|------------------| | Transition period nutrition and intake | Monitor dry matter intake, ration formulation, and feeding frequency. | | Energy and mineral metabolism | Evaluate body condition score, blood ketone bodies, and calcium status. | | Housing and cow comfort | Assess stall design, bedding, stocking density, and pen changes. | | Early clinical assessment | Train staff to identify subtle changes in appetite, rumen fill, and manure. | ## System Context and Pathophysiology ### Anatomy and Displacement Mechanism The abomasum normally lies on the abdominal floor to the right of the midline. When gas accumulates because of atony or outflow obstruction, the organ becomes buoyant. In left displacement the abomasum migrates under the rumen, while right displacement often involves torsion. The initial atony is frequently a consequence of reduced feed intake coupled with hypocalcemia or hyperketonemia around calving. [Merck Veterinary Manual](https://www.merckvetmanual.com/) describes this sequence and emphasizes that concurrent diseases such as metritis or mastitis further suppress smooth muscle contractility. ### Metabolic Interactions A cow in negative energy balance mobilizes body fat, leading to elevated nonesterified fatty acids and beta hydroxybutyrate. This hyperketonemic state is well documented as a predictor of subsequent DA. [Evaluation of nonesterified fatty acids and β-hydroxybutyrate in transition dairy cattle in the northeastern United States: Critical thresholds for prediction of clinical diseases](https://api.elsevier.com/content/abstract/scopus_id/77949305779) (2010) confirms that cows with elevated ketone bodies in the first week after calving have significantly higher odds of DA. Similarly, [Impact of hyperketonemia in early lactation dairy cows on health and production](https://api.elsevier.com/content/abstract/scopus_id/59349120499) (2009) shows that hyperketonemia reduces appetite and abomasal motility, creating a feedback loop that exacerbates risk. Low blood calcium at parturition further impairs gastrointestinal muscle function. [Physiological Changes at Parturition and Their Relationship to Metabolic Disorders](https://api.elsevier.com/content/abstract/scopus_id/0031184206) (1997) details how the sudden calcium demand for colostrum production can cause subclinical hypocalcemia in a large proportion of cows, suppressing rumen and abomasal tone. These metabolic disturbances are not independent, they interact with feeding behavior, making integrated monitoring essential. ## Planning Decisions for Prevention ### Monitoring Dry Matter Intake Feed intake is the single most informative indicator of impending metabolic disease. Cows that reduce intake in the last week before calving or fail to increase intake immediately postpartum are at elevated risk. Management decisions should include daily evaluation of feed push-up timing, orts weight, and bunk space allocation. [Monitoring metabolic health of dairy cattle in the transition period](https://api.elsevier.com/content/abstract/scopus_id/77955855948) (2010) stresses that group-level feed consumption trends provide actionable data, but individual observation remains critical. Where automated feeding systems are absent, routine assessment of rumen fill score helps detect early deviations. Professional escalation is warranted when more than 10% of prefresh cows show reduced appetite or when postpartum intakes do not rise steadily by day three in milk. ### Housing and Cow Comfort Physical environment directly influences feeding time and social stress. Overcrowded pens, insufficient stalls, and poor footing all reduce voluntary intake and rumination. [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) and [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) guidance emphasize that dairy facilities should provide at least one stall per cow and allow unrestricted access to feed for 20 to 22 hours per day. Pen moves during the transition period should be minimized, each group change disturbs social hierarchy and temporarily lowers feed intake. Housing decisions must be made well before the dry period begins to ensure that prefresh and fresh pens are appropriately sized and bedded. ### Early Clinical Assessment Because DA becomes more difficult to correct once the abomasum is displaced, early recognition of precursor signs is paramount. Staff should be trained to evaluate the following daily in fresh cows: reduced time at the bunk, a tucked abdomen, and decreased fecal volume or consistency. Auscultation over the left ribcage for a high pitched ping is diagnostic for left displacement, but this finding may not appear until the abomasum has already migrated. Therefore reliance on physical examination alone is insufficient. [Measurement of ketones in milk or urine](https://www.aphis.usda.gov/livestock-poultry-disease) provides an earlier indication of metabolic imbalance and can prompt intervention before displacement occurs. Veterinarians should be consulted when any fresh cow exhibits a persistent drop in feed intake beyond 24 hours or when subpopulations of cows show elevated ketone bodies on routine testing. ## Facilities or Environment Housing design and management directly influence the risk of displaced abomasum (DA) in dairy cows. Facilities that restrict voluntary movement or limit access to feed and water create conditions predisposing cows to hypomotility and gas accumulation in the abomasum. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) notes that cows housed in tie,stalls or small free,stalls with inadequate lunge space for rising and lying down experience higher rates of abomasal displacement compared with cows in well,designed loose,housing systems. [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) guidance emphasizes that overcrowding, particularly in the immediate postpartum period, reduces feed bunk space and increases competition, leading to erratic intake patterns and subacute ruminal acidosis. Acidosis is a documented antecedent to DA because volatile fatty acid accumulation alters rumen motility and triggers abomasal atony. Flooring quality also matters. Slippery concrete surfaces increase the risk of injury and reduce the frequency of lying bouts, which in turn decreases rumination time. Cows that spend more time standing on hard, wet surfaces have altered rumen fill and are less likely to consume adequate dry matter. The [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) resource on dairy housing recommends providing deep,bedded resting areas with at least one stall per cow, along with a feed alley that allows all cows to eat simultaneously. Failure to meet these space allowances constitutes a failure pattern associated with elevated DA incidence. Ventilation and heat abatement are additional environmental factors, heat stress depresses feed intake and promotes ketosis, both of which increase DA risk. ## Nutrition and Water Nutritional management in the transition period is the most extensively studied risk factor for DA. The periparturient diet must support a gradual increase in energy density while maintaining adequate physical effective fiber to stimulate rumination. [PubMed record 42357793](https://pubmed.ncbi.nlm.nih.gov/42357793/) and [PubMed record 42214273](https://pubmed.ncbi.nlm.nih.gov/42214273/) describe how excessive energy density in the close,up dry cow diet leads to rumen adaptation failure and postpartal subacute acidosis. When concentrates are increased too quickly, rumen pH drops, volatile fatty acid profiles shift, and abomasal motility is compromised. The [Impact of hyperketonemia in early lactation dairy cows on health and production](https://api.elsevier.com/content/abstract/scopus_id/59349120499) (2009) demonstrates that hyperketonemia is both a consequence and a cause of DA, elevated beta,hydroxybutyrate (BHBA) is associated with reduced feed intake and increased fat mobilization, further perpetuating abomasal atony. Water availability and quality are often overlooked. Cows require 20,30% more water in early lactation than in the dry period. Reduced water intake leads to dehydration, decreased rumen turnover, and increased risk of ketosis. [PubMed record 42205063](https://pubmed.ncbi.nlm.nih.gov/42205063/) reports that water trough placement and flow rate affect drinking behavior, and cows that cannot access water within 15 m of the feed bunk after milking are more likely to exhibit subclinical ketosis. Additionally, the composition of the diet,particularly the ratio of forage to concentrate,must be monitored for effective fiber (physically effective neutral detergent fiber). Forage particle length shorter than 2.5 cm reduces rumination time and increases the likelihood of acidosis and subsequent DA. ## Production,Stage Decisions The transition period (three weeks prepartum to three weeks postpartum) is the critical window for DA prevention. Grouping strategies that maintain stability and minimize social stress are essential. [Physiological Changes at Parturition and Their Relationship to Metabolic Disorders](https://api.elsevier.com/content/abstract/scopus_id/0031184206) (1997) describes how the rapid decline in plasma calcium at calving impairs smooth muscle function, including abomasal contractions. Therefore, managing hypocalcemia through diet anion,cation balance is a production,stage decision that directly affects DA risk. [Monitoring metabolic health of dairy cattle in the transition period](https://api.elsevier.com/content/abstract/scopus_id/77955855948) (2010) recommends that cows calve at a body condition score of 3.0 to 3.25 (on a 1,5 scale), cows too fat or too thin have higher DA rates. Overconditioned cows mobilize excessive non,esterified fatty acids (NEFA), leading to ketosis and abomasal displacement. The dry period length also plays a role. Shortening the dry period to fewer than 40 days does not allow adequate rumen adaptation and may increase the risk of metabolic disorders, including DA. Conversely, dry periods exceeding 70 days are associated with overconditioning. [PubMed record 42092557](https://pubmed.ncbi.nlm.nih.gov/42092557/) indicates that primiparous cows require special attention, their smaller rumen capacity and lower feed intake capacity make them more vulnerable to negative energy balance and DA. Therefore, separate feeding and grouping for first,lactation animals in the early postpartum period is a recommended production,stage decision. ## Records Systematic record,keeping is necessary to identify herds with elevated DA incidence and to track management changes. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) provides benchmarking data for DA prevalence in US dairy herds. Producers should record each DA event by date, parity, days in milk, and method of correction (surgery, rolling, or other). These records allow calculation of herd,level incidence and comparison with industry benchmarks. Additionally, recording body condition score at calving, ketosis test results, and postpartum disease events (mastitis, metritis, retained placenta) helps identify patterns. [Monitoring and testing dairy herds for metabolic disease](https://api.elsevier.com/content/abstract/scopus_id/4744355224) (2004) advises integrating DA records with milk production data and feed intake records to detect suboptimal transition management. When DA incidence exceeds 3,5% in a herd, the producer should examine records for common risk periods (e.g., weeks 2,4 postpartum) and reassess diet, housing, and health protocols. ## Welfare Displaced abomasum is a painful condition that compromises animal welfare. Cows with LDA or RDA exhibit inappetence, depression, abdominal distension, and abnormal stance. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) includes provisions for prompt diagnosis and treatment to minimize suffering. Delayed intervention leads to abomasal necrosis, peritonitis, and death. Prevention is the primary welfare strategy, facilities that prevent acidosis, hypocalcemia, and ketosis reduce the pain associated with these metabolic disturbances. Additionally, proper handling during surgery or percutaneous correction is essential to avoid additional pain. Producers and veterinarians should assess cows daily for clinical signs and intervene early, instead of waiting until signs become severe. ## Worker and [Food Safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention) Farm workers handling DA cases must use appropriate restraint and sanitization protocols. [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) guidelines emphasize that surgical correction requires clean instruments and a sterile field to prevent abscess formation and peritonitis. Workers should be trained to recognize the condition and to communicate with veterinary professionals. Food safety concerns arise when cows are treated with anti,inflammatory drugs or antibiotics, milk withdrawal periods must be strictly followed. Incorrect drug administration or failure to withhold milk can result in violative residues. Additionally, cows that are not treated promptly may be salvaged through culling, but proper withdrawal times for meat must be observed. Routine monitoring of DA incidence and treatment records helps ensure that no treated animal enters the food chain prematurely. ## Failure Patterns Common management failures that increase DA risk include inadequate transition cow nutrition, failure to provide a consistent feeding schedule, and ignoring subclinical ketosis. [PubMed record 41887508](https://pubmed.ncbi.nlm.nih.gov/41887508/) identifies that abrupt diet changes at calving are a recurring pattern in high,incidence herds. Another failure pattern is insufficient bunk space,fewer than 30 cm per cow in the postpartum group leads to sorting of the total mixed ration and selective intake of concentrates, triggering acidosis. Delayed diagnosis also contributes to poor outcomes, cows that are not examined for subtle signs such as decreased rumen fill, reduced milk yield, or mild ketosis are more likely to develop a severe left displacement. Finally, failure to correct hypocalcemia at calving is a widespread omission. [Evaluation of nonesterified fatty acids and β-hydroxybutyrate in transition dairy cattle in the northeastern United States: Critical thresholds for prediction of clinical diseases](https://api.elsevier.com/content/abstract/scopus_id/77949305779) (2010) demonstrates that elevated NEFA prepartum and BHBA postpartum are strong predictors of DA, yet many herds do not perform routine metabolic testing. ## Practical Monitoring Practical monitoring for DA should include daily observation of feed intake, rumen fill, and manure consistency. Cows that eat less than 60% of expected intake in the first week postpartum warrant individual examination. Weekly testing of BHBA in a subset of cows (e.g., 12,15 animals per week in a 200,cow herd) allows detection of subclinical ketosis before clinical DA appears. The [Impact of hyperketonemia in early lactation dairy cows on health and production](https://api.elsevier.com/content/abstract/scopus_id/59349120499) recommends using on,farm ketone meters for rapid assessment. Additionally, monitoring dry matter intake on a group level with feed bunks or scales provides an early indicator of metabolic imbalance. [Body condition scoring](/knowledge/animal-farming/farm-management/body-condition-scoring-a-tool-for-feed-management) at dry,off, calving, and 30 days in milk helps identify cows at excessive risk. When combined with veterinary consultation, these monitoring practices allow herd,level risk assessment and targeted interventions. The goal is to detect and correct underlying metabolic disturbances before they progress to abomasal displacement. ## Health Observation and Early Detection Routine health observation during the first two to four weeks after calving is the foundation for identifying cows at risk of or already developing a displaced abomasum. The primary observable change is a sudden decrease in feed intake, often accompanied by reduced rumen fill and a drop in milk yield. Caretakers should check every fresh cow at least twice daily, noting appetite, rumen motility, and fecal consistency. Cows that go off feed, show scant or pasty manure, or exhibit a tucked,up abdomen warrant immediate physical examination (Merck Veterinary Manual). Auscultation of the left flank is the classic field test for left displaced abomasum. A high,pitched, resonant ping heard over the left side of the abdomen, especially after flicking the abdominal wall, is strongly suggestive of gas trapped in the displaced organ. However, a ping alone does not confirm displacement, a right,sided ping may indicate a right displacement or cecal dilatation. Palpation per rectum can help differentiate, but definitive diagnosis often requires ultrasound or exploratory laparotomy (PubMed record 42357793). Because early abdominal sounds can be subtle, any suspicion should prompt measurement of ketone bodies in blood or milk. Elevated β,hydroxybutyrate concentrations above an established herd threshold are a marker of negative energy balance and increased risk of displacement (Evaluation of nonesterified fatty acids and β,hydroxybutyrate in transition dairy cattle, 2010). Cows that have already developed hyperketonemia should be examined for abomasal displacement even if a typical ping is absent. Monitoring of nonesterified fatty acids in the prepartum period can identify individuals likely to experience excessive fat mobilization (Monitoring metabolic health of dairy cattle in the transition period, 2010). The combination of intake observation, rumen fill scoring, and ketone testing provides a practical surveillance system that allows intervention before clinical signs become severe. ## Biosecurity and Housing Considerations Displaced abomasum is not a contagious disease, but the management and environment that predispose cows to negative energy balance can propagate herd,wide problems. Biosecurity in this context refers to minimizing dietary errors, reducing overcrowding, and maintaining consistent feed delivery. Cows should have unrestricted access to a well,formulated transition ration that includes adequate physically effective fibre and a balanced concentrate supply. Abrupt changes in the diet or feed component should be avoided during the three weeks before and after calving (WOAH Terrestrial Animal Health Code). Housing plays a major role. Overcrowded pens, poor bunk space, and insufficient lying area increase competition and reduce dry matter intake. Stall design that allows cows to rise and lie down without obstruction helps maintain normal rumen function. Pen surfaces should be dry and clean to lower the risk of concurrent diseases such as metritis or mastitis, which can further depress feed intake (USDA APHIS Livestock and Poultry Disease). The calving area itself should be a low,stress environment with adequate bedding and space for cows to express natural behaviours during parturition (FAO Animal Production and Health). Early clinical assessment extends beyond individual cow checks to herd,level monitoring. Recording calving dates, body condition scores, and the incidence of other periparturient diseases helps identify management breakdowns. Herds with a high rate of retained placenta, metritis, or clinical ketosis often have a corresponding increase in displaced abomasum incidence. These correlations underscore the need for comprehensive transition,cow protocols that address both nutrition and environment (USDA National Animal Health Monitoring System). ## Diagnostic and Veterinary Escalation When a cow shows persistent inappetence, decreased milk production, or a detectable left,sided ping, veterinary involvement should be sought promptly. A veterinarian can perform a systematic examination that includes abdominal auscultation, ballottement, percussion, and ultrasound. Ultrasound is especially useful to confirm the location of the abomasum and to rule out other conditions such as abomasal ulceration or peritonitis (PubMed record 42205063). Blood chemistry may reveal electrolyte imbalances and acidosis that accompany displacement and influence the choice of therapy. Early intervention improves the prognosis. Medical therapy with calcium solutions, magnesium, and anti,inflammatory drugs may temporarily support the cow but does not correct the displacement. Surgical correction,through a standing left flank laparotomy or a right paramedian approach,remains the standard treatment for left displaced abomasum (Merck Veterinary Manual). The veterinarian will decide on the technique based on cow temperament, available facilities, and the surgeon’s experience. Post,operative care includes continued monitoring for hydration, pain, and the resumption of normal feed intake. In herds where the incidence exceeds 5,6% of fresh cows, a longitudinal investigation is warranted. Nutritional analysis, forage fibre evaluation, and feeding management audits can identify risk factors that predispose the herd (Monitoring and testing dairy herds for metabolic disease, 2004). Such an approach aligns with the goals of improving herd sustainability,reducing disease burden, extending cow longevity, and lowering the need for antibiotic or surgical intervention. The economic losses from each case, including veterinary costs, milk drop, and increased culling, can be substantial. ## Uncertainty and Professional Escalation Not all cows that develop a displaced abomasum show classic signs. Some exhibit only vague indications such as intermittent anorexia, weight loss, or a prolonged recovery from ketosis. In these cases, reliance solely on physical examination may lead to underdiagnosis. The accuracy of herd,level monitoring also depends on the quality of record keeping and the training of personnel. Producers who detect a rising incidence of displacement despite adherence to standard recommendations should consult a [veterinary nutritionist](/blog/careers/becoming-a-veterinary-nutritionist-education-certification-and-practice) or a herd health specialist. Uncertainty remains around the precise thresholds for prepartum nonesterified fatty acids that predict displacement in every cow, individual variability in liver function, parity, and rumen capacity can alter susceptibility (Impact of hyperketonemia in early lactation dairy cows, 2009). Consequently, a single high,risk marker should prompt careful observation instead of immediate action, and a combination of markers strengthens the case for intervention. Research continues into methods for early prediction, including automated monitoring of feeding behaviour and rumen temperature. Until validated tools become widely available, close manual observation remains the cornerstone. Producers are advised to maintain a low threshold for veterinary evaluation when a cow exhibits two or more risk factors: parity 2+, high body condition at calving, short dry period, or a calving disorder (Physiological Changes at Parturition, 1997). Professional escalation is always appropriate when a cow fails to respond to supportive therapy within 24,48 hours or when the biosecurity plan fails to lower herd incidence. ## Frequently Asked Questions **Q1: How soon after calving can a displaced abomasum develop?** Most cases appear within the first two to four weeks after parturition. The peak risk window is during the period of greatest negative energy balance, typically from day 3 to day 14 postpartum. **Q2: Can a cow recover without surgery?** Spontaneous correction is rare. Non,surgical rolling onto the back followed by controlled rolling may occasionally reposition the abomasum, but recurrence is common. Surgical correction is the recommended method for achieving permanent resolution. **Q3: What is the relationship between ketosis and displaced abomasum?** Ketosis and displacement are closely linked. Cows with subclinical or clinical ketosis are at substantially higher risk because high circulating ketone bodies are a marker of severe energy deficit and reduced rumen motility. **Q4: Is a displaced abomasum heritable?** There is some evidence for a genetic component. Cows that have had a previous episode are more likely to experience another, and daughters of affected dams have a slightly elevated risk. However, management factors exert a much larger influence. **Q5: How can I monitor feed intake effectively in fresh cows?** Record group,level dry matter intake daily and note individual cows that fail to eat at feeding time. Use feed,push frequency in free,stall barns to keep feed accessible. Automated feeding systems that track individual intakes are available for some operations. **Q6: Does housing type affect the incidence of displaced abomasum?** Yes. Research indicates that well,managed freestall barns with adequate space and dry bedding can lead to lower rates than bedded packs, but the effect depends heavily on stocking density and stall design. **Q7: When should I call the veterinarian for a fresh cow off feed?** Call if the cow has not eaten for more than 12 hours, shows a significant drop in milk yield, has an abdominal ping, or produces scant faeces. Early veterinary involvement reduces the need for intensive care. **Q8: What is the most cost,effective prevention strategy?** Ensure a smooth dry,cow to lactation transition with a well,balanced ration, adequate fibre, and minimal metabolic stress. Avoid overconditioning cows at dry,off, and provide excellent calving management to reduce dystocia and retained placenta. ## Educational Veterinary Notice The information in this article is intended for reference use by trained animal,health professionals and experienced livestock managers. It does not replace a veterinary examination, diagnosis, or treatment plan. Individual dairy cows may have complex concurrent diseases that require clinical judgment. The references cited provide supporting evidence but do not constitute exclusive or standard protocols. Veterinary oversight is mandatory for diagnosis, treatment decisions, and herd,level health planning. ## Related Farming Guides - [Dairy Cattle Farming Nutrition Housing Health Signals And Herd Management](/knowledge/animal-farming/dairy-cattle/dairy-cattle-farming-nutrition-housing-health-signals-and-herd-management) - [Transition Cow Management From Dry Off To Freshening](/knowledge/animal-farming/dairy-cattle/transition-cow-management-from-dry-off-to-freshening) - [Dairy Calf Colostrum Management](/knowledge/animal-farming/dairy-cattle/dairy-calf-colostrum-management) - [Milking Routine And Parlor Hygiene](/knowledge/animal-farming/dairy-cattle/milking-routine-and-parlor-hygiene) - [Dairy Farm Records That Drive Better Decisions](/knowledge/animal-farming/dairy-cattle/dairy-farm-records-that-drive-better-decisions) ## Related Clinical & Scientific Guides * [Evaluating Feed Additives for Dairy Cow Performance](/knowledge/animal-farming/dairy-cattle/evaluating-feed-additives-for-dairy-cow-performance) * [Dairy Barn Fire Safety: Design and Prevention Measures](/knowledge/animal-farming/dairy-cattle/dairy-barn-fire-safety-design-prevention) * [Dairy Cow Pregnancy Loss Records and Review](/knowledge/animal-farming/dairy-cattle/dairy-cow-pregnancy-loss-records-and-review) ## References and Further Reading - [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) - [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) - [USDA APHIS Livestock and Poultry Disease](https://www.aphis.usda.gov/livestock-poultry-disease) - [Merck Veterinary Manual](https://www.merckvetmanual.com/) - [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.