Poultry Reproduction: Understanding Breeding and Fertility

Successful poultry reproduction depends on understanding the reproductive anatomy and physiology of both males and females, then applying that knowledge through practical breeding management. For farmers, the measurable outcomes are fertility and hatchability, which directly determine chick numbers, flock replacement costs, and overall enterprise profitability. This article explains the biological basis of poultry breeding and provides a management checklist for improving fertility in commercial and smallholder flocks.

At a Glance: Key Factors Affecting Poultry Fertility

Reproductive Anatomy and Physiology in Poultry

Female Reproductive System

The hen has a single functional reproductive tract on the left side of the body. The ovary produces yolks, and the oviduct is divided into distinct regions that each contribute to egg formation. The infundibulum captures the released yolk and is the site where fertilization occurs. The magnum adds albumen, the isthmus deposits shell membranes, and the shell gland or uterus forms the shell. The vagina is the final passage for the egg and is also the site where sperm are deposited during natural mating.

Sperm storage is a unique feature of avian reproduction. After mating or artificial insemination, sperm travel to sperm storage tubules located at the junction of the vagina and shell gland. Sperm can remain viable in these tubules for days or weeks, allowing a single insemination to fertilize multiple eggs. The sperm storage tubules are critical to understanding why insemination timing and semen quality matter so much in poultry breeding. Research on sperm fitness assessment highlights that sperm must survive a sequence of steps after deposition, including reaching the storage tubules, remaining viable inside them, reacquiring motility, and finally binding to and penetrating the egg [24].

Male Reproductive System

The rooster has two testes located internally near the kidneys. Sperm production occurs continuously once the bird reaches sexual maturity, and semen is transported through the ductus deferens to the cloaca. The rooster does not have accessory sex glands like mammals, so semen is relatively concentrated. The phallus is a small non-intrusive organ, and mating involves a cloacal kiss where the male and female vents are pressed together.

Sperm quality depends on several factors including testicular function, hormone balance, and overall health. Aquaporins, which are proteins that transport water and small molecules, are present in the male reproductive organs and sperm of birds and mammals. Research suggests these proteins may serve as future biomarkers for male fertility assessment in livestock and poultry [10]. While this technology is not yet available for routine farm use, it indicates the direction of fertility testing.

Breeding Management for Natural Mating

Flock Structure and Male to Female Ratio

The ratio of males to females in a breeding flock directly affects fertility. Too few males means some females may not be mated regularly. Too many males leads to competition, injury to females, and wasted resources. The optimal ratio depends on the species and breed. For chickens, a common range is one rooster per eight to twelve hens. For turkeys, the ratio is often lower due to the larger body size of toms and the potential for injury to hens.

Male broiler breeders have a prominent impact on flock fertility because the male to female ratio is low in breeder flocks [13]. This means the fertility contribution of each individual male is substantial. If one male is subfertile or infertile, the impact on overall flock fertility is greater than in flocks with higher male numbers.

Male Condition and Reproductive Aging

Reproductive aging is a documented challenge in male broiler breeders. Fertility decline is well documented after 45 weeks of age [13]. Several factors contribute to this decline including overweight condition, dysfunction of Sertoli and Leydig cells, compromised antioxidant capacity, hormone imbalances, and epididymal lithiasis or stone formation [13]. These factors reduce sperm production and quality.

Body weight management is the most practical intervention for maintaining male fertility. Overweight roosters have reduced mating activity and poorer semen quality. Feed allocation should be adjusted to maintain males within their target weight range throughout the breeding period. Nutritional strategies that support antioxidant status and improve sperm fatty acid profiles have shown promise in mitigating reproductive aging [13].

Mating Behavior and Observation

Farmers should observe mating activity directly, especially during early morning and late afternoon when mating is most frequent. Signs of active mating include courtship behavior, cloacal contact, and the presence of mating-related feather loss on the backs of hens. If mating activity declines, check male health, body condition, and the male to female ratio.

Artificial Insemination in Poultry

When to Use Artificial Insemination

Artificial insemination is used in several situations. Turkeys are commonly inseminated artificially because their large body size makes natural mating difficult and can cause injury to hens. Broiler breeders are sometimes inseminated artificially to improve fertility, especially in older flocks. Artificial insemination is also used for genetic improvement programs and for preserving genetic resources [8].

The technique allows more control over which males contribute to the next generation and can improve fertility when natural mating is not effective. However, artificial insemination requires training, equipment, and careful semen handling. The benefits must be weighed against the labor and skill requirements [27].

Semen Collection and Handling

Semen collection in poultry is performed using abdominal massage. The rooster or tom is restrained, and gentle pressure is applied to the abdomen to stimulate ejaculation. Semen is collected into a small container and must be protected from contamination, temperature extremes, and direct sunlight.

Semen quality declines rapidly after collection. Sperm are sensitive to temperature shock, and even short periods at incorrect temperatures reduce fertility. For liquid storage, semen is diluted in extenders that provide nutrients and protect sperm membranes. Research on grey partridge semen found that short-term liquid storage for 24 hours at 5 degrees Celsius reduced sperm motility, viability, and the proportion of morphologically normal spermatozoa [17]. The same study found that higher sperm doses consistently resulted in higher fertility rates in both fresh and stored semen [17].

Insemination Timing and Technique

The timing of insemination relative to egg production matters because of the sperm storage tubules. Insemination should be scheduled so that sperm are present in the storage tubules when eggs are being fertilized. For chickens, insemination is typically performed in the afternoon after most eggs have been laid for the day. This timing reduces the risk of the inseminated semen being expelled with an egg.

The insemination dose and technique affect fertility. Sperm dose significantly affects fertilization success, with higher doses resulting in higher fertility rates [17]. The insemination should deposit semen in the vagina, and the hen should be held in position briefly after insemination to prevent semen loss.

Semen Storage and Preservation

Two major types of storage technology are used for avian sperm preservation: liquid storage and cryopreservation [8]. Liquid storage keeps semen viable for hours to a few days at cool temperatures. Cryopreservation involves freezing semen for long-term storage, which is important for preserving genetic resources.

Cryopreservation of poultry semen is more challenging than in mammals. The composition of the cryo-diluent is considered the most important factor for developing effective cryopreservation methods for avian semen [8]. Research continues to identify extenders and cryoprotectants that improve post-thaw sperm quality and fertility [8].

Nutrition and Fertility

Feed Formulation for Breeding Flocks

Nutrition directly affects reproductive performance in both males and females. Breeding flocks require diets formulated for reproduction instead of for growth or egg production alone. Key nutrients include protein, energy, vitamins, and minerals.

Vitamin A has been studied for its effects on reproduction in aged laying hens. Research on Sinai laying hens at 52 weeks of age found that diets supplemented with 2000 or 6000 IU of vitamin A per kilogram of diet increased fertility rate and decreased early embryonic mortality [22]. The same study found that increasing vitamin A from 4000 to 6000 IU per kilogram significantly boosted hatchability rates [22]. These findings support attention to vitamin levels in breeder diets, especially for older flocks.

Diet and Fertility Relationships

The relationship between diet and fertility has been studied extensively in humans, and some patterns are relevant to poultry nutrition. Research on human fertility found that adherence to healthy diets favoring seafood, poultry, whole grains, fruits, and vegetables is related to better fertility in women and better semen quality in men [6]. While this research is not directly about poultry, it supports the general principle that diet quality affects reproductive outcomes.

For poultry, the practical implication is that breeder diets should be balanced and complete. Deficiencies or excesses of specific nutrients can impair fertility. Feed ingredients also matter. Research on Japanese quail found that corn germ meal inclusion at 10 percent of the diet enhanced feed conversion ratio, while inclusion at 20 percent deteriorated it [25]. The same study found that feeding 10 percent corn germ meal increased fertility and chick weight after hatching and reduced embryonic death [25]. This demonstrates that alternative feed ingredients can be used successfully when inclusion rates are appropriate.

Body Condition and Feed Allocation

Body condition is a practical indicator of nutritional status in breeding birds. Both undercondition and overcondition reduce fertility. Underweight birds may not have sufficient nutrient reserves for reproduction. Overweight birds, especially males, have reduced mating activity and fertility.

Feed allocation should be adjusted based on body weight monitoring. For broiler breeders, controlled feeding is standard practice because these birds have been selected for rapid growth and will overconsume if given free access to feed. The goal is to maintain birds at the target body weight for their age and breed.

Environmental Factors Affecting Fertility

Heat Stress

Heat stress is a major environmental determinant that adversely affects poultry performance worldwide [7]. The adverse effects of high environmental temperature include decreases in growth rate, body weight, egg production, egg weight, egg quality, meat quality, semen quality, fertility, and hatchability [7]. These effects cause substantial financial losses to the poultry industry.

Selection of birds for high performance has increased their susceptibility to heat stress [7]. This means that modern commercial breeds may be more sensitive to high temperatures than traditional breeds. Research on Thai native and black-boned chickens found that heat stress significantly reduces monthly egg production, and the two genotypes had different heat stress thresholds [19]. Thai native chickens exhibited greater tolerance to elevated thermal conditions, with a threshold of 74 compared to 72 for black-boned chickens [19].

Practical heat stress management includes providing shade, ensuring adequate ventilation, and using cooling systems such as fans, misters, or evaporative cooling pads. Water availability is critical during hot periods. Feeding during cooler parts of the day can help maintain feed intake. Genetic strategies are being explored to select birds with greater heat tolerance [7].

Lighting and Photoperiod

Photoperiod affects poultry reproduction, and lighting management is an important approach for increasing egg production [9]. In birds, photoperiod regulation is a complex physiological process [9]. Supplementary artificial lighting has been shown to increase mean egg production, the length of the egg production period, and fertility [9].

Lighting programs should be matched to the breed and production system. For geese, a meta-analysis of five studies on White Roman geese found that supplementary artificial light increased egg production and fertility [9]. However, the authors noted that examination of more breeds is necessary to make more definitive assessments [9].

For chickens, lighting programs typically involve increasing day length to stimulate sexual maturity and maintain egg production. The intensity, duration, and consistency of lighting all matter. Sudden changes in lighting can cause stress and reduce production.

Housing and Ventilation

Housing conditions affect fertility through their influence on bird health, comfort, and behavior. Good ventilation removes moisture, ammonia, and heat from the house. Poor ventilation leads to respiratory problems and reduced feed intake, which can impair reproduction.

Flooring and litter conditions matter for natural mating. Slippery or wet floors can cause injury during mating. Clean, dry litter provides good footing and reduces the risk of footpad lesions and other health problems.

Health Management and Biosecurity

Disease Effects on Reproduction

Disease can reduce fertility through direct effects on the reproductive organs or through general illness that reduces feed intake, body condition, and mating activity. Respiratory diseases can cause egg production drops and poor shell quality. Reproductive tract infections can cause peritonitis and reduced fertility.

Health management practices directly affect production and reproduction outcomes [26]. A comprehensive health program includes vaccination, biosecurity, monitoring, and treatment when needed. The USDA National Agricultural Library provides resources on animal health and welfare that can help farmers understand disease prevention and management [2].

Biosecurity Measures

Biosecurity is the first line of defense against disease introduction and spread. Key measures include controlling visitor access, disinfecting equipment and vehicles, preventing contact with wild birds, and isolating new or returning birds. Rodent and insect control are also important because pests can transmit diseases.

The World Organisation for Animal Health provides guidance on animal health and welfare standards [4]. Following these standards helps protect flock health and supports international trade in poultry products.

Vaccination and Medication

Vaccination programs should be designed for the specific diseases present in the region and the production system. The U.S. Food and Drug Administration provides resources on animal veterinary products, including vaccines and medications [3]. Farmers should work with their veterinarian to develop appropriate vaccination schedules.

Medication use must follow label instructions and withdrawal periods. The FDA regulates animal drugs and provides guidance on their safe use [3]. Improper medication use can lead to drug residues in eggs or meat, which is a food safety concern.

Records and Measurements

Fertility Records

Fertility is measured by candling eggs during incubation. Eggs that show embryonic development are fertile. Eggs that are clear or show no development are infertile. Fertility percentage is calculated as the number of fertile eggs divided by the total number of eggs set, multiplied by 100.

Fertility records should be maintained for each hatch. Records should include the date, flock identification, male and female ages, insemination or mating dates, and the number of eggs set. These records allow farmers to track fertility trends and identify problems early.

Hatchability Records

Hatchability is measured as the number of chicks hatched divided by the number of fertile eggs set, multiplied by 100. Hatchability of all eggs set is another useful measure that accounts for both fertility and embryonic survival.

Hatchability records should include the number of eggs set, the number of fertile eggs, the number of chicks hatched, and the timing of hatch. Early, mid, and late embryonic mortality should be recorded when possible. This information helps identify whether problems are related to fertility, egg handling, incubation conditions, or nutrition.

Semen Quality Assessment

Semen quality can be assessed using several in vitro tests. These tests evaluate sperm motility, viability, morphology, membrane integrity, acrosome integrity, and DNA integrity [24]. Each test evaluates specific sperm features, and combining several assays provides a more reliable fertility estimate [24].

The sperm-egg interaction assay using the inner perivitelline layer of chicken eggs is highlighted as a single test that evaluates multiple sperm characteristics and is highly correlated with fertility [24]. This test is more complex than basic semen evaluation but provides more useful information.

For routine farm use, microscopic evaluation of sperm motility and morphology is the most practical approach. Sperm should show vigorous forward movement and normal morphology. The proportion of morphologically normal spermatozoa can be surprisingly low even in fresh ejaculates, as found in grey partridge research where fresh ejaculates had only 14.2 percent morphologically normal spermatozoa [17].

Common Failure Patterns in Poultry Breeding

Low Fertility with Normal Hatchability

When fertility is low but hatchability of fertile eggs is normal, the problem is likely related to mating or insemination. Possible causes include insufficient males, poor male fertility, mating problems due to body condition or leg issues, and improper insemination technique.

Check the male to female ratio, observe mating activity, and assess male body condition. If artificial insemination is used, review the semen collection and insemination procedures. Semen quality should be evaluated microscopically.

Normal Fertility with Low Hatchability

When fertility is normal but hatchability is low, the problem is likely related to egg handling, storage, incubation, or nutrition. Possible causes include poor egg storage conditions, improper incubation temperature or humidity, egg contamination, and nutritional deficiencies.

Review egg collection and storage procedures. Eggs should be collected frequently, stored at the correct temperature and humidity, and set promptly. Incubation conditions should be monitored and calibrated. Egg breakage and contamination should be minimized.

Seasonal Fertility Decline

Fertility often declines during hot weather due to heat stress [7]. High ambient temperature reduces semen quality, fertility, and hatchability [7]. Seasonal declines can also be related to changes in photoperiod.

Implement heat stress management measures during hot periods. Provide shade, ventilation, and cooling. Adjust feeding times to cooler parts of the day. Ensure adequate water supply. Consider genetic selection for heat tolerance [7].

Age-Related Fertility Decline

Fertility declines with age in both males and females. Male broiler breeders show fertility decline after 45 weeks of age [13]. This decline is associated with overweight condition, testicular dysfunction, and other physiological changes [13].

Management strategies to mitigate reproductive aging include body weight control, nutritional support for antioxidant status, and attention to sperm fatty acid profiles [13]. Some producers use artificial insemination to maintain fertility in older flocks.

Genetic Considerations in Poultry Breeding

Genetic Improvement Programs

Genetic improvement programs aim to select birds with superior production and reproduction traits. The Food and Agriculture Organization of the United Nations provides resources on animal production, including genetic improvement [1]. The USDA Agricultural Research Service conducts research on animal production and protection, including genetics [5].

Genetic improvement requires accurate records of performance traits. Pedigree records track the relationships between birds. Selection decisions are based on estimated breeding values that account for the genetic merit of individual birds.

Reproductive Traits and Genetic Selection

Fertility is an important economic trait that relies on the genetic merit of both males and females [11]. Despite the importance of the paternal contribution to reproductive success, most research has focused on the female [11]. The advent of omics technologies has stimulated the search for accurate predictors of male fertility [11].

Omics approaches including genomics, transcriptomics, proteomics, and metabolomics have contributed significantly to understanding chicken reproduction [12]. These technologies have led to the discovery of genes associated with reproductive features and disorders [12]. They have also helped create biomarkers for fertility and embryonic viability [12].

For most farmers, genetic selection is not a direct activity. Instead, farmers purchase breeding stock from hatcheries and breeding companies that conduct genetic improvement programs. The quality of the breeding stock purchased directly affects the fertility and hatchability of the flock.

Breed Differences in Reproduction

Different breeds and lines have different reproductive characteristics. Research on the Nicobari chicken breed found that dwarfism, which occurs naturally in this breed, affected growth and production traits [23]. Dwarf hens had a higher age at first egg and lower egg weights, but better shell thickness [23]. Fertility and hatchability were lower in dwarf dams mated with dwarf sires than in crosses between normal and dwarf birds [23].

This research demonstrates that breed-specific characteristics must be considered in breeding management. Farmers should understand the expected reproductive performance of their breed and manage accordingly.

Practical Breeding Management Checklist

Pre-Breeding Preparation

Before the breeding season begins, complete the following steps. Review the previous season's fertility and hatchability records to identify problem areas. Check the health status of the flock and complete any needed vaccinations. Assess male body condition and cull males that are underweight, overweight, or showing signs of poor health. Verify that the male to female ratio is appropriate for the breed and production system. Clean and disinfect housing, equipment, and incubators. Calibrate incubator temperature and humidity sensors. Stock feed and supplements needed for the breeding period.

During the Breeding Period

Monitor body weight of males and females weekly. Observe mating activity regularly, especially during early morning and late afternoon. Collect and record fertility and hatchability data for each hatch. Evaluate semen quality if artificial insemination is used. Maintain consistent lighting schedules. Monitor house temperature and humidity, especially during hot periods. Check feed and water supply daily. Watch for signs of disease or stress. Keep detailed records of all management activities.

Post-Breeding Review

At the end of the breeding period, review the season's records. Calculate fertility and hatchability percentages for the entire period and for shorter intervals. Identify patterns of decline and their timing. Compare performance to breed standards and previous seasons. Evaluate the effectiveness of management interventions. Document lessons learned for the next breeding season.

Welfare and Safety Considerations

Bird Welfare in Breeding Flocks

Breeding flocks have specific welfare needs. Males and females should have adequate space for natural behavior, including mating. Overcrowding causes stress and injury. Perches and other environmental enrichment can support natural behavior.

The USDA National Agricultural Library provides resources on animal health and welfare [2]. The World Organisation for Animal Health sets standards for animal welfare [4]. Farmers should be familiar with these standards and apply them to their operations.

Worker Safety in Breeding Operations

Handling breeding birds carries some risks. Roosters and toms can be aggressive, especially during the breeding season. Workers should be trained in safe handling techniques. Protective clothing, including gloves and eye protection, should be used when handling birds or collecting semen.

Artificial insemination requires close contact with birds and involves handling of semen. Workers should follow hygiene protocols to prevent disease transmission between birds and to protect their own health.

Food Safety Considerations

Food safety is relevant to breeding operations because eggs from breeding flocks may enter the food chain if they are not used for hatching. The FDA regulates food safety for animal products [3]. Farmers should follow good hygiene practices when collecting and handling eggs.

If medications are used in breeding flocks, withdrawal periods must be observed before eggs or meat enter the food chain. The FDA provides guidance on drug use in animals [3]. Farmers should keep accurate medication records and follow label instructions.

Professional Escalation Criteria

When to Consult a Veterinarian

Consult a veterinarian when fertility or hatchability drops suddenly or persistently below expected levels. Also consult when birds show signs of disease, when semen quality is poor, when there are unexplained embryonic deaths, or when you need help designing a health program. A veterinarian can perform diagnostic testing, recommend treatments, and help identify underlying causes of reproductive problems.

When to Consult a Nutritionist

Consult a nutritionist when feed formulation changes are needed, when birds are not maintaining target body weight, when fertility problems may be related to nutrition, or when using alternative feed ingredients. A nutritionist can formulate diets that meet the specific needs of breeding flocks.

When to Consult a Geneticist or Breeder

Consult a geneticist or breeder when selecting breeding stock, when considering genetic improvement programs, or when reproductive problems may have a genetic basis. Breeding companies can provide information on the expected performance of their lines and recommendations for management.

Frequently Asked Questions

What is the ideal male to female ratio for a chicken breeding flock?

The ideal ratio depends on the breed and production system. For standard chickens, one rooster per eight to twelve hens is commonly recommended. For broiler breeders, the ratio is often lower because males have a prominent impact on flock fertility [13]. Observe mating activity and fertility records to determine if the ratio needs adjustment.

How long can sperm remain viable in the hen after mating or insemination?

Sperm are stored in sperm storage tubules located at the junction of the vagina and shell gland [24]. Sperm can remain viable in these tubules for days or weeks, allowing a single insemination to fertilize multiple eggs. The exact duration depends on the species, breed, and individual hen.

What causes low fertility in a flock with normal hatchability?

Low fertility with normal hatchability suggests the problem is related to mating or insemination instead of egg handling or incubation. Check the male to female ratio, observe mating activity, assess male body condition, and evaluate semen quality. If artificial insemination is used, review the collection and insemination procedures.

How does heat stress affect poultry reproduction?

Heat stress adversely affects production, reproduction, and growth performance in poultry [7]. High environmental temperature decreases semen quality, fertility, and hatchability [7]. Heat stress also reduces egg production, egg weight, and egg quality [7]. Management measures include shade, ventilation, cooling systems, and adjusting feeding times.

What is the best time to inseminate hens artificially?

Insemination is typically performed in the afternoon after most eggs have been laid for the day. This timing reduces the risk of the inseminated semen being expelled with an egg. The insemination dose should be adequate, as higher sperm doses consistently result in higher fertility rates [17].

Can vitamin supplementation improve fertility in older flocks?

Research on aged laying hens found that dietary supplementation with vitamin A at 6000 IU per kilogram of diet improved reproductive efficiency and antioxidative status [22]. Fertility rate increased and early embryonic mortality decreased with supplementation at 2000 or 6000 IU per kilogram [22]. Work with a nutritionist to determine appropriate supplementation levels for your flock.

How is fertility measured in a breeding flock?

Fertility is measured by candling eggs during incubation. Eggs that show embryonic development are fertile. Fertility percentage is calculated as the number of fertile eggs divided by the total number of eggs set, multiplied by 100. Fertility records should be maintained for each hatch to track trends over time.

What are the signs of reproductive aging in male broiler breeders?

Fertility decline is well documented in male broiler breeders after 45 weeks of age [13]. Contributing factors include overweight condition, Sertoli and Leydig cell dysfunction, compromised antioxidant capacity, hormone imbalances, and epididymal lithiasis [13]. Body weight management and nutritional strategies can help mitigate these effects [13].

Related Farming Guides

• Donkey Breeding and Reproduction Management
• Draft Horse Breeding and Reproduction Management
• Water Buffalo Reproduction and Breeding Management
• Pig Breeding Cycle and Reproductive Management
• Dairy Cow Reproduction: Synchronization and Breeding Management

References and Further Reading

• FAO Animal Production and Health. Food and Agriculture Organization of the United Nations.
• Animal Health and Welfare. USDA National Agricultural Library.
• Animal and Veterinary Resources. U.S. Food and Drug Administration.
• Animal Health and Welfare. World Organisation for Animal Health.
• Animal Production and Protection. USDA Agricultural Research Service.
• Diet and fertility: a review.. American journal of obstetrics and gynecology, 2018.
• Climate change and heat stress: Impact on production, reproduction and growth performance of poultry and its mitigation using genetic strategies.. Journal of thermal biology, 2021.
• Advances in storage of poultry semen.. Animal reproduction science, 2022.
• Meta-analysis: Supplementary artificial light and goose reproduction.. Animal reproduction science, 2020.
• Aquaporins: New markers for male (in)fertility in livestock and poultry?. Animal reproduction science, 2021.
• The 'omics' revolution: Use of genomic, transcriptomic, proteomic and metabolomic tools to predict male reproductive traits that impact fertility in livestock and poultry.. Animal reproduction science, 2020.
• The Omics Revolution in Understanding Chicken Reproduction: A Comprehensive Review.. Current issues in molecular biology, 2024.
• Recent strategies to mitigate reproductive aging in male broiler breeders: A review.. Animal reproduction science, 2024.
• Operational model of the French livestock and poultry genetic resources management system and its implications.. 2026.
• Corigendum to "Integrative genomic analysis and gene expression patterns reveal a cardio-neuroendocrine signaling network for heat adaptation in geographically diverse chickens" [Poultry Science, Volume 105, Issue 6, June 2026, 106744].. 2026.
• Chromosome-level genome assembly of the small-sized Taihang donkey (Equus asinus).. 2026.
• Artificial insemination with liquid-stored and fresh semen in grey partridge (Perdix perdix L.).. 2026.
• Quorum sensing-mediated odor regulation in livestock and poultry manure: an emerging perspective.. 2026.
• Refined THI Models for Evaluating the Effects of Heat Stress on Egg Production in Thai Native and Black-Boned Chickens.. 2026.
• Establishment and evaluation of hematological and serum biochemical reference intervals in Chinese local donkey populations.. 2026.
• Erratum to "Aquaporins: New markers for male (in)fertility in livestock and poultry?" [Anim. Reprod. Sci. 231 (2021) 106807].. Animal Reproduction Science, 2021.
• Effects of supplemental vitamin A on reproduction and antioxidative status of aged laying hens, and growth, blood indices and immunity of their offspring. Poultry Science, 2024.
• Effect of a Unique Dwarfism on Growth, Production, and Reproduction Performance of the Nicobari Chicken Breed. The Journal of Poultry Science, 2025.
• Sperm fitness assessment in poultry: Brief review of in vitro methods.. Animal Reproduction Science, 2024.
• Use of corn germ meal and bile acids in laying quail diets: effect on production, reproduction, health and economics. Poultry Science, 2024.
• Poultry Health Management Practices and Their Effect on Production and Reproduction. Revista Electronica De Veterinaria, 2023.
• Artificial insemination in poultry. Zuchtungskunde, 2005.

This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.