# Hay Testing and Forage Allocation for Goat Herds


## Key Takeaways

-   **Objective Nutritional Assessment:** Hay testing provides crucial objective data on crude protein, fiber (ADF/NDF), energy (TDN/NE), and key minerals (Ca, P, Mg, K) to prevent nutritional deficiencies and toxicities, which are critical for immune competence and metabolic health as referenced by WOAH standards.
-   **Targeted Forage Allocation:** Analysis allows for the partitioning of hay lots based on nutrient profiles, enabling efficient allocation to specific production groups (lactating does, growing kids, dry does, bucks) with distinct protein and energy requirements, thereby optimizing growth, lactation, and reproductive performance.
-   **Informed Ration Balancing and Supplementation:** Test results are essential for veterinarians and nutritionists to formulate precise concentrate feeds and mineral mixes, avoiding over- or under-supplementation and preventing issues like urinary calculi or poor bone development, as supported by USDA NAHMS data.
-   **Disease Prevention and Welfare:** Routine forage analysis acts as a preventive management tool by identifying potential mycotoxin contamination (requiring specific assays if suspected) and nutritional imbalances that lower immune function, thereby reducing susceptibility to parasitism and metabolic disorders, aligning with WOAH animal welfare standards.
-   **Storage and Economic Optimization:** Moisture content and mold risk detected through testing guide storage decisions and predict spoilage rates, while nutrient content per ton enables cost-per-unit calculations for least-cost ration formulation and informs long-term production record keeping and economic planning.
-   **Diagnostic and Biosecurity Tool:** Hay testing serves as a first-line diagnostic tool for herd health issues like poor growth or reproductive failure, helping differentiate nutritional causes from infectious agents, and is a critical component of biosecurity by identifying and preventing the introduction of pathogens and contaminants into the herd.

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Hay testing provides the objective nutritional data necessary to balance goat rations, prevent deficiencies and toxicities, and allocate forage efficiently across production groups. Forage analysis supports group feeding decisions, nutrition consultations with veterinarians or extension specialists, storage management, and long-term production record keeping.

## At a Glance

| Factor | Relevance to Goat Herds | How Hay Testing Supports |
| ------ | ----------------------- | ------------------------ |
| Group Feeding | Lactating does, growing kids, dry does, and bucks have different protein and energy requirements. | Analysis partitions hay lots by crude protein, fiber, and mineral content for targeted allocation. |
| Nutrition Consultations | Veterinarians and animal nutritionists require accurate forage quality data to formulate supplements and avoid over- or under-supplementation. | Test results enable precise, evidence-based recommendations for concentrate feeds and mineral mixes. |
| Storage Decisions | Moisture content, mold risk, and nutrient deterioration affect feed safety and shelf life. | Testing at harvest and during storage helps predict spoilage rates and guides hay purchase timing. |
| Production Records | Herd performance benchmarks rely on consistent feed quality information across seasons and years. | Regular testing documents annual and seasonal variation, supporting trend analysis and economic planning. |

## System Context for Hay Testing in Goat Herds

Goats are selective, intermediate feeders that can digest higher fiber fractions than cattle but still require forage of adequate nutrient density to meet production demands. The nutrient composition of hay varies widely with forage species, maturity at harvest, growing conditions, and curing or ensiling methods. [Effect of forage species and ensiling conditions on silage composition and quality and the feed choice behaviour of goats](https://api.elsevier.com/content/abstract/scopus_id/85062567837) confirmed that goats exhibit distinct preferences for forages based on fermentation characteristics and physical form. Without laboratory analysis, visual appraisal and historical assumptions often fail to detect marginal protein levels, suboptimal energy content, or mineral imbalances that can depress milk yield, kid growth, and reproductive performance.

Hay testing also supports disease prevention. Nutritional deficiencies lower immune competence and predispose herds to parasitism and metabolic disorders, per standards referenced in the [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/). Routine forage analysis is therefore a preventive management tool, also a production optimization step.

## Planning Decisions Informed by Forage Analysis

Testing results directly influence several operational planning decisions:

- Which hay lots to purchase or feed first. Hays high in neutral detergent fiber (NDF) but low in crude protein may be reserved for dry does or maintenance groups, while higher-quality lots are allocated to lactating females or growing kids.
- Whether to blend forages or add supplements. A hay testing report that reveals marginal protein levels prompts a nutrition consultation to adjust concentrate or protein meal inputs.
- Storage duration and inventory management. High-moisture hay or hay with elevated mold counts, as detected by analysis, must be used quickly or discarded to avoid mycotoxin exposure. [Testing for variation in animal preference for Jesup tall fescue hays with wild-type, novel, or no fungal endophyte](https://api.elsevier.com/content/abstract/scopus_id/54949142838) illustrates how forage variety and endophyte status affect intake and animal performance, emphasizing the need for lot-specific quality data.
- Economic assessments. Knowing the actual nutrient content per ton enables cost-per-unit-of-protein or cost-per-unit-of-energy calculations, informing least-cost ration formulation.

The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) and related [USDA APHIS](https://www.aphis.usda.gov/livestock-poultry-disease) resources note that systematic record keeping of feed quality supports outbreak investigations and herd health benchmarking. Hay testing records become part of that data ecosystem.

## Core Management Framework for Hay Allocation

A practical framework for incorporating hay testing into goat herd management involves three steps: sampling, laboratory analysis, and record integration.

Representative sampling is essential. Use a hay probe to collect cores from multiple bales in a lot, then submit to a certified forage testing laboratory. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) and [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) guidelines recommend sampling at harvest, at several points during storage, and before feeding a new lot. Results should include dry matter, crude protein, acid detergent fiber (ADF), NDF, total digestible nutrients (TDN) or net energy estimates, and key minerals (calcium, phosphorus, magnesium, potassium). If endophyte contamination or mycotoxins are suspected, request additional assays.

Once results are returned, consult with a veterinarian or animal nutritionist to integrate forage data into the feeding program. The nutrition consultation is a professional escalation point: interpreting forage analysis requires knowledge of goat physiological stages, interaction with other feedstuffs, and local mineral profiles. Use the test report to adjust concentrate amounts, select mineral formulations, and decide which hay lots are fed to which groups.

Record each test result with the lot identifier, harvest date, storage conditions, and the group fed. Over multiple seasons, these records reveal trends that guide future hay purchasing contracts, grazing management, and herd production targets. The framework is cyclical: test, consult, allocate, record, and repeat.

## Hay Testing in Relation to Storage and Environment

Hay testing results directly inform storage decisions that preserve forage quality and prevent spoilage. Moisture content, a standard parameter in forage analysis, determines the risk of microbial growth during storage. Hays with moisture levels above safe thresholds should be used earlier or dried further before stacking. The presence of mold or elevated fungal counts in hay tests signals inadequate drying conditions or poor bale density, requiring managers to adjust harvest timing or aeration practices. Environmental factors such as ambient humidity and barn ventilation interact with hay composition, for example, legume hays with higher protein content are more prone to heating due to microbial activity. The [FAO](https://www.fao.org/animal-production/en/) guidelines emphasize that periodic retesting after storage detects nutrient losses from respiration or leaching. Facilities with enclosed storage benefit from results that indicate whether hay retains its feeding value over time. Producers should layer hay test data with environmental monitoring to decide which lots to feed first and which to reserve for later production stages.

## Group Feeding Strategies Based on Forage Analysis

Forage analysis enables precise allocation of hay to different groups within a goat herd according to physiological stage and production goals. The crude protein concentration, neutral detergent fiber (NDF), and acid detergent fiber (ADF) reported in a hay test allow managers to match feed to the requirements of lactating does, growing kids, dry does, or breeding bucks. Studies on the [feed choice behaviour of goats](https://api.elsevier.com/content/abstract/scopus_id/85062567837) demonstrate that goats prefer certain forage types based on palatability and nutrient density, but group feeding limits individual selection, hay test data therefore substitutes for animal choice by ensuring the offered forage meets group needs. When multiple hay lots are available, results guide which lot is offered to high-producing animals (higher protein, lower fiber) and which to maintenance groups. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) notes that goats require higher dietary protein for lactation compared to sheep and cattle, so hay testing is especially critical to verify that legume or grass-legume mixes contain adequate crude protein for milking does. In mixed herds, a single hay analysis may not suffice if body condition scores vary widely, separate testing of each lot protects against overfeeding or underfeeding particular groups.

## Nutrition Consultation and Ration Balancing

Hay testing provides the foundation for professional nutrition consultations. Veterinarians and animal nutritionists use laboratory reports to calculate how much concentrate supplement, mineral premix, or protein source must be added to the forage-based diet. Without a forage analysis, supplementation becomes guesswork, risking either nutrient excesses that waste feed or deficiencies that impair health and production. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) has documented that routine feed testing improves herd-level nutritional management in livestock operations. When a hay test reveals marginal calcium-to-phosphorus ratios or low trace mineral levels, consultants can adjust mineral mixes accordingly to prevent urinary calculi in males or poor bone development in kids. The [FAO](https://www.fao.org/animal-production/en/) feed analysis protocols stress that ration balancing must account for dry matter intake, which is influenced by hay palatability and digestibility as reflected in NDF values. Producers who present complete hay test reports to their veterinarian facilitate timely adjustments before production losses occur.

## Production-Stage Decisions: Growth, Lactation, and Maintenance

Hay quality requirements shift sharply across production stages, and testing allows stage-specific allocation. Growing kids need hay with moderate protein (e.g., 14 to 16 percent crude protein on a dry matter basis) and low fiber to support rapid skeletal and muscle development, a hay test confirming these values justifies feeding a high-quality forage without unnecessary concentrate. Lactating does have the highest nutritional demands, testing ensures that the hay offered does not become the limiting factor in milk yield or quality. A study comparing [carcass and meat quality traits of kids](https://api.elsevier.com/content/abstract/scopus_id/85125752187) illustrates that forage quality during the pre-weaning and growing phases influences ultimate meat characteristics, underscoring the importance of consistent hay testing across production cycles. Dry does in early gestation can tolerate higher-fiber hays with lower protein, which helps prevent excessive body condition gain and associated metabolic problems. Production-stage decisions also extend to breeding bucks: hay testing reveals whether a forage supports optimal body condition for fertility without causing obesity. Records of hay test results linked to production records (milk weights, growth rates, breeding success) create a feedback loop that refines future forage purchases and allocation plans.

## Records and Monitoring for Continuity

Systematic recordkeeping of hay test results, lot identification, feeding rates, and animal performance amplifies the value of forage analysis. 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 record maintenance that support traceability and disease investigation, in a goat operation, linking hay test data to health events (e.g., pregnancy toxemia, enterotoxemia) helps identify feed-related causes. Producers should record the laboratory, sampling date, lot number, and all analyte values for each hay purchase or harvest. These records become reference points for negotiating with hay suppliers or adjusting conservation practices. Practical monitoring includes weekly [body condition scoring](/knowledge/animal-farming/farm-management/body-condition-scoring-a-tool-for-feed-management) of representative animals from each feeding group and comparing trends to the hay test database. Fecal consistency, rumen fill scores, and rate of feed refusal offer real-time checks that complement laboratory data. When a hay test indicates that a lot is lower in energy than expected, managers can increase the feeding rate or supplement with concentrates, then monitor whether body condition stabilizes. Cross-referencing production records with hay test results over multiple seasons reveals patterns such as declining hay quality from a particular supplier or optimal moisture windows for local harvests.

## Welfare Implications of Inadequate Forage Allocation

Improper hay allocation based on untested assumptions compromises goat welfare. Feeding hay that is too low in protein or energy leads to weight loss, poor coat condition, reduced immune function, and increased susceptibility to parasitic infections. Conversely, feeding overly rich hay to maintenance groups can cause obesity, hepatic lipidosis, and joint stress. The [WOAH](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) animal welfare standards for livestock emphasize the provision of feed that meets nutritional requirements and is free from harmful contaminants, hay testing is the primary means of verifying that requirement for stored forages. Mycotoxin contamination, detectable only through laboratory analysis, poses a chronic welfare risk because goats cannot avoid toxic hays in confinement feeding. Welfare monitoring must include regular assessment of animals fed from each hay lot, with attention to signs of nutritional deficiency such as pica (abnormal chewing), rough hair coats, and low activity levels. When hay test results reveal a deficiency or toxicity, immediate reformulation of the diet or replacement of the affected hay protects animal wellbeing. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) advises veterinary involvement whenever herd-level health or performance deviates from expectations, and hay test reports provide essential data for that consultation.

## Worker and [Food Safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention) Considerations

Hay testing also supports worker and food safety. Moldy hay with high dust levels exacerbates respiratory problems for workers handling the feed, testing for aerobic stability and fungal species helps managers decide whether to wet the hay, feed in wellventilated areas, or discard hazardous lots. The [FAO](https://www.fao.org/animal-production/en/) guidelines for safe animal feed include recommendations to monitor for physical hazards, pesticide residues, and biological contaminants, all of which can be addressed through routine hay testing. For dairy goat operations, hay contaminated with weeds that produce alkaloids or that accumulate nitrates can lead to milk residues, affecting food safety. Testing for nitrate levels is particularly important if the hay was harvested under drought stress or heavy nitrogen fertilization. Although goats are less sensitive to some plant toxins than other ruminants, the [USDA APHIS](https://www.aphis.usda.gov/livestock-poultry-disease) disease surveillance programs note that feedborne intoxications can mimic infectious disease outbreaks, delaying diagnosis. A hay test that includes a screen for common antinutritional factors provides an early warning system that protects both animal products and human handlers.

## Common Failure Patterns in Forage Programs

Several recurring failures undermine the benefits of hay testing. One common pattern is testing only a single sample from a heterogeneous hay supply, leading to nonrepresentative results. Proper sampling requires multiple cores from different bales in a lot, as emphasized by [FAO](https://www.fao.org/animal-production/en/) protocols. Another failure is ignoring changes in hay quality between harvest and feeding, loss of vitamin A or oxidative rancidity of fats can occur during storage, yet only a fresh test captures these changes. Managers who treat hay test data as static risk feeding animals degraded forage. A third pattern is failing to adjust allocation as the herd's physiological composition changes, a hay that sufficed for dry does becomes inadequate when the lactation season begins. The [effect of forage species and ensiling conditions](https://api.elsevier.com/content/abstract/scopus_id/85062567838) on silage composition illustrates that even within a single forage type, variable harvest conditions produce divergent quality profiles, requiring testing of each cutting. Without regular testing, producers often compensate by overfeeding concentrate, raising feed costs and increasing the risk of ruminal acidosis.

## Practical Monitoring Methods for Hay Quality and Intake

Beyond laboratory analysis, producers can monitor hay quality and intake using straightforward observations. Measuring feed refusals daily provides a crude index of palatability, if large amounts of a particular hay are left uneaten, testing for high NDF or unpalatable constituents is warranted. Rumen fill and fecal scoring give immediate feedback on fiber digestibility, although these observations should be corroborated by hay test NDF values. Body condition scoring every two weeks in each feeding group allows early detection of weight loss or gain that correlates with hay quality. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) describes physical examination techniques that reveal subtle signs of nutritional stress, such as dull eyes, reduced skin elasticity, and slow escape response. These practical monitoring methods bridge the gap between infrequent laboratory tests and daily feeding decisions. When monthly hay test reports are combined with weekly condition scores and feed intake records, the operation builds a reliable system for adjusting forage allocation in real time. This approach reduces reliance on guesswork and positions hay testing as a continuous management tool instead of a one-time diagnostic event.

Hay testing also informs ration formulation but also plays a critical role in health monitoring, biosecurity, and sustainable management. Regular analysis of forage nutrients and contaminants allows herd managers to anticipate and correct imbalances before clinical signs appear, reducing reliance on reactive treatments.

**Health observation.** The nutrient profile of hay directly influences goat body condition, immune competence, and reproductive performance. Protein and energy levels affect growth rates, milk yield, and resistance to internal parasites. Mineral content, particularly calcium, phosphorus, copper, and selenium, must be evaluated relative to goat physiological stages, imbalances can precipitate urinary calculi in males or weak offspring in does. Mycotoxin contamination, often indicated by visible mold or heating during storage, can cause feed refusal, liver damage, or immunosuppression. Studies on feed-choice behaviour in goats (see Effect of forage species and ensiling conditions on silage composition and quality and the feed choice behaviour of goats, 2019) demonstrate that goats can detect quality differences, but palatability alone does not guarantee nutritional adequacy. Hay testing provides objective data that confirm whether observed intakes meet metabolic demands.

**Biosecurity.** Hay and other forages can introduce pathogens, weed seeds, and fungal spores into a herd. Moisture content measured through testing helps predict the risk of post-storage spoilage. High-moisture hay (>15,18 percent, though precise thresholds depend on local humidity) encourages mould growth and potential mycotoxin production. Testing for the presence of toxic endophytes, as exemplified by work on tall fescue varieties (Testing for variation in animal preference for Jesup tall fescue hays with wild-type, novel, or no fungal endophyte, 2008), allows managers to avoid feeding infected forage to pregnant or lactating does. The [WOAH Terrestrial Animal Health Code](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) emphasises feed biosecurity as part of general disease prevention. Removing haylots that test positive for harmful contaminants prevents herd exposure and reduces the need for veterinary interventions.

**Diagnostic and veterinary escalation.** When a herd presents with poor growth, reduced feed intake, diarrhoea, or reproductive failure, hay testing becomes a first-line diagnostic tool. It helps distinguish nutritional deficiencies from infectious or parasitic causes. For instance, a low copper test may explain ill-thrift or poor coat quality, while an elevated calcium-to-phosphorus ratio can point toward urinary obstruction risk. Recent reports (see [PubMed record 40053018](https://pubmed.ncbi.nlm.nih.gov/40053018/) and [PubMed record 38141243](https://pubmed.ncbi.nlm.nih.gov/38141243/)) illustrate the role of feed analysis in differential diagnosis of metabolic disorders in small ruminants. However, testing should complement, not replace, a thorough clinical examination by a veterinarian. If test results suggest a toxicity or deficiency, samples of serum, liver, or urine may be needed for confirmation. The [Merck Veterinary Manual](https://www.merckvetmanual.com/) provides standard reference ranges for trace minerals, but those ranges must be interpreted in context of diet, age, and physiological state. Professional escalation occurs when results fall outside expected intervals or when multiple animals show similar clinical signs despite adequate feed intake.

**Uncertainty.** Hay testing carries inherent limitations. A single composite sample may not capture the variability within a haystack or across different cuttings. Moisture, nutrient content, and contaminant levels can differ between core samples. Laboratory methods also have analytical tolerances, inter-laboratory variation exists. Therefore, results must be treated as estimates instead of absolute values. When borderline or unexpected values appear, repeat sampling from additional bales is advisable. Furthermore, goat nutritional requirements vary by breed, stage of production, and environmental stress. A diet that appears adequate on paper may still cause subclinical problems if animals have concurrent illness or parasitism. The [FAO Animal Production and Health](https://www.fao.org/animal-production/en/) guidelines encourage using forage analysis as part of an integrated approach that includes regular body condition scoring, parasite monitoring, and veterinary supervision. Uncertainty does not invalidate the tool, rather, it underscores the need for professional interpretation.

**Sustainability.** Precision allocation of hay based on laboratory analysis reduces waste and feed costs. Feeding low-quality hay to animals with lower energy requirements (e.g., dry does) and reserving high-quality hay for lactating or growing animals optimises nutrient use. This practice decreases the amount of imported supplements needed, lowering the carbon footprint of the operation. Avoiding overfeeding of protein and phosphorus also reduces nitrogen and phosphorus excretion into the environment. The [USDA National Animal Health Monitoring System](https://www.aphis.usda.gov/livestock-poultry-disease/nahms) and related extension programs promote feed testing as a component of environmentally sustainable livestock production. Furthermore, storing hay at the moisture level indicated by testing helps prevent spoilage losses, conserving the energy invested in harvesting and baling. Long-term records of hay analyses allow producers to track changes in soil fertility, cutting management, and weather patterns, supporting adaptive management decisions.

## Frequently Asked Questions

**1. How often should I submit hay samples for my goat herd?**
Test at least once per cutting or whenever the hay source changes. Also test after prolonged storage if mould or heating is observed.

**2. Which nutrients are most important to request in a standard hay test for goats?**
Crude protein, total digestible nutrients (or energy), calcium, phosphorus, magnesium, copper, selenium, and zinc. A mycotoxin screen is advisable when hay appears mouldy or has been wet.

**3. How do I collect a representative hay sample?**
Use a hay probe to sample ten to twenty bales selected from different locations within the lot. Combine the cores into one composite bag. Avoid taking samples only from the exposed ends.

**4. Can hay testing replace a veterinary nutrition consultation?**
No. Testing provides raw data, translating that data into a balanced ration for a specific herd requires knowledge of goat physiology, feedstuff interactions, and current production goals.

**5. What should I do if my hay tests low in crude protein?**
Supplement with a higher-protein forage (e.g., legume hay) or a concentrated protein source such as soybean meal, canola meal, or a commercial goat supplement. Consult a nutritionist for precise amounts.

**6. Is a mycotoxin test necessary for all hay lots?**
It is strongly recommended for any hay that shows visible mould, a musty odour, or evidence of heating. Testing is also prudent when goats exhibit feed refusal, diarrhoea, or undiagnosed illness.

**7. How does hay quality affect reproductive success in goats?**
Inadequate energy and protein can delay puberty, reduce conception rates, and lower milk production. Mineral imbalances, especially in selenium and copper, may cause weak kids, retained placenta, or poor colostrum quality.

**8. Can I use hay test results to compare different suppliers?**
Yes. Objective nutrient profiles allow you to assess value per unit of nutrient and to select hay that best matches your herd’s nutritional requirements. Keep records of each supplier’s analyses for future purchasing decisions.

**Educational veterinary notice.** Hay testing is a practical tool for improving herd health, reducing waste, and supporting sustainable goat production. Results must be interpreted by a qualified veterinarian or animal nutritionist who can integrate them with clinical findings, body condition scores, and production records. For specific feeding recommendations and diagnostic workups, consult your local veterinary practitioner or extension specialist.

## Related Farming Guides

- [Goat Farming Dairy And Meat Production Browse Kidding Parasite Risk And Welfare](/knowledge/animal-farming/goats/goat-farming-dairy-and-meat-production-browse-kidding-parasite-risk-and-welfare)
- [Meat Goat Pasture And Browse Management](/knowledge/animal-farming/goats/meat-goat-pasture-and-browse-management)
- [Parasite Control Without Driving Anthelmintic Resistance](/knowledge/animal-farming/goats/parasite-control-without-driving-anthelmintic-resistance)
- [Goat Farm Biosecurity Checklist](/knowledge/animal-farming/goats/goat-farm-biosecurity-checklist)
- [Livestock Nutrition And Feed Management A Cross Species Decision Framework](/knowledge/animal-farming/farm-management/livestock-nutrition-and-feed-management-a-cross-species-decision-framework)

## Related Clinical & Scientific Guides

* [Goat Breeding Season Planning: Timing, Nutrition, and Health Checks](/knowledge/animal-farming/goats/goat-breeding-season-planning)
* [Alfalfa Hay for Goats: Feeding Decisions and Mineral Context](/knowledge/animal-farming/goats/alfalfa-hay-for-goats-feeding-decisions-and-mineral-context)
* [Goat Fiber Production: Cashmere and Mohair Management](/knowledge/animal-farming/goats/goat-fiber-production-cashmere-mohair-management)


## 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.


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