# Pekin Duck Breeding: Timing, Fertility and Care Pekin duck breeding succeeds when three things line up: ducks that are old enough and heavy enough to breed, a light schedule that drives the reproductive axis, and a drake-to-duck ratio that keeps the females fertile without tearing up their backs and legs. Pekins reach sexual maturity around 5 to 7 months of age, respond strongly to day length, and are among the heaviest common domestic ducks. That weight is the central problem in this breed. Pekin drakes are often poor natural maters, so owners frequently see good egg numbers with disappointing fertility. Fixing that usually means managing body condition, checking feet and legs, adjusting the sex ratio, and in some flocks moving to artificial insemination. This guide covers the full breeding cycle, from choosing and conditioning breeders through incubation and hatch, with a troubleshooting table for the fertility problems that actually show up in backyard Pekin flocks. ## At a Glance: The Pekin Breeding Cycle | Stage | Timing | Key action | |--|--|--| | Selection | Before breeding season | Choose sound, well-grown birds, check feet and legs | | Sexual maturity | About 5 to 7 months | Do not rush young drakes into heavy service | | Conditioning | 4 to 6 weeks before collecting eggs | Manage weight, provide breeder nutrition | | Light schedule | Ongoing | Provide long day length to drive reproduction | | Mating ratio | Throughout | About 1 drake to 4 to 6 ducks | | Egg collection | Daily | Collect clean eggs, store cool, set fresh | | Incubation | 28 days | 37.5 C (99.5 F), 55 to 65% humidity, higher at hatch | | Hatch | Days 26 to 28 | Stop turning, raise humidity, leave ducklings to dry | | Brooding | First weeks after hatch | Warm, dry, draft-free brooder | ## Why Pekins Are Different from Other Backyard Ducks The Pekin is a large, fast-growing duck. That body type shapes everything about breeding it. A heavy frame means more stress on the legs and feet during mounting, and it means the drake has to work harder to achieve a successful mating. The result is a breed that can lay well but fertilize poorly if management is loose. Pekins also respond to light in ways that are well documented. The hypothalamic-pituitary-gonadal axis, the hormone chain that controls reproduction, is regulated by day length through a deep brain photoreceptor system [1]. In Pekin ducks, expression of these photoreceptor genes rises during development and reaches its highest relative levels around week 19, a period the authors describe as typically peak fertility in ducks. Gonadotropin-releasing hormone rises after the photoreceptor signal at the onset of puberty, and gonadal steroids rise after that, with estradiol preceding testosterone [1]. In plain terms, the bird's brain reads the length of the day, and that reading sets the whole reproductive cascade in motion. This is why lighting is not a minor detail in Pekin duck breeding. It is the switch. ## Sexual Maturity and Timing in Pekins ### When Do Pekin Ducks Start Breeding? Pekin ducks generally reach sexual maturity around 5 to 7 months of age. The developmental data support this window. In a study tracking [gene expression](/blog/guides/gene-expression) and hormones from hatch through 31 weeks, the reproductive signaling molecules climbed through the juvenile period, with the deep brain photoreceptor genes reaching their highest relative expression at week 19 and gonadal steroids increasing after week 14 [1]. Week 19 is roughly 4.5 months. That is the hormonal ramp. Full, reliable breeding behavior and consistent fertile eggs usually follow a few weeks later, which places practical sexual maturity at about 5 to 7 months for most backyard Pekins. Drakes often show mounting behavior and interest before the hens are producing well. Do not read that as readiness. A young drake that is still growing should not be worked hard, because his frame is not finished and his legs are still developing. ### The First Breeding Season Pekin hens lay large eggs. Average egg weight in one comparison of Pekin and Brown Tsaiya ducks was about 75 g for Pekins at 30 weeks of age [2]. Large eggs are not automatically better for hatching. In a study of Pekin hatching eggs sorted by weight, heavy eggs (over 83 g) had the lowest hatchability of total and fertile eggs compared with light (under 75 g) and medium (76 to 82 g) eggs [3]. Heavy eggs also had thinner shells, at 0.3862 mm, while light eggs had the strongest shells at 2.5 kg/cm2 [3]. The practical takeaway is that you should not chase the biggest possible eggs. Medium-sized Pekin eggs hatch best. ### Breeder Age Matters Flock age changes egg quality and hatchability. As Pekin breeders age, egg weight and yolk percentage increase while albumen percentage, shell thickness, and yolk index decrease [4]. Shell thickness drops and pore density rises with increasing parental age [5]. In a study comparing production cycles, eggs from a flock in its second cycle at 78 weeks differed significantly from first-cycle eggs at 31 weeks in albumen index, Haugh unit, shell percentage, yolk composition, hatching weight, and duckling growth [6]. Older Pekin hens still produce, but their eggs are structurally weaker and their embryos face more risk. If you are hatching from an older flock, expect lower hatchability and handle eggs carefully. ## Photoperiod: The Light Switch for Pekin Fertility ### How Day Length Drives Reproduction Long days stimulate Pekin reproduction and short days suppress it. In an experiment housing adult Pekins under simulated summer (14.5 hours of bright light), simulated winter (8 hours of bright light), and augmented winter (8 hours bright plus 16 hours at a low 15 lux), winter conditions reduced both the percentage of eggs laid and the number of fertilized eggs compared with summer conditions [7]. The augmented winter lighting prevented that loss in both eggs laid and fertilized eggs [7]. That last point is the useful one for backyard owners. You do not need full summer brightness around the clock. You need enough light hours and enough intensity to keep the reproductive axis engaged. ### Light Intensity Hits Drakes Harder The same study found that low light intensity in Pekin breeder barns had a greater impact on the fertility of drakes than on hens [7]. Drakes are the more light-sensitive sex. If your flock is laying but fertility has fallen, the drake is the first suspect, and the light he is standing in is the first thing to check. ### Older Evidence on Light and Semen Earlier work on Pekins in subtropical conditions found that artificial light had a favorable effect on semen volume, sperm motility, concentration, viability, and normality across two laying seasons, and that light stimulus improved fertility and hatchability [8]. Night feeding by itself had no reliable effect on semen production, so the improvement traced back to light rather than to feeding schedule [8]. ### Practical Lighting for a Backyard Pekin Flock The evidence supports a long day for breeding Pekins. A practical approach is to provide roughly 14 to 15 hours of light per day during the breeding season, with the bright period at a meaningful intensity rather than a dim glow. The augmented winter condition in the research used 8 hours at 65 lux plus 16 hours at 15 lux, and that was enough to prevent the winter fertility loss [7]. A dim night light alone is not the same as a long bright day. Keep the light schedule stable. Sudden changes in day length signal a season change to the bird's brain, and the reproductive cascade responds accordingly [1]. ## The Drake-to-Duck Ratio ### Why 1 to 4 or 1 to 6 The standard working ratio for Pekins is about one drake to four to six ducks. This range balances two competing problems. Too few drakes and fertility drops, because not every hen gets mated often enough. Too many drakes and the hens get overworked. Pekin drakes are heavy, and repeated mounting damages the feathers and skin on a hen's back and neck, and stresses her legs. Overmating also increases the chance of injury to the drakes themselves as they compete. A ratio of 1 to 4 suits a smaller flock where you want strong fertility pressure. A ratio of 1 to 6 is gentler on the hens and works when the drakes are proven and active. If you see bare backs, broken feathers, or hens avoiding the drakes, you have too much drake pressure and should either remove a drake or add more hens. ### Rearing Drakes with Females Some producers mix a few female ducklings into all-male pens during rearing, on the theory that early exposure to females improves later reproductive success. A controlled study tested this by placing three females into four of eight male rearing pens and then measuring mounting behavior, testosterone, and flock fertility after the pens were combined at 20 to 22 weeks of age [9]. None of the measured variables were affected by the rearing treatment [9]. So early female exposure is not a reliable fertility tool in Pekins. Do not count on it to fix a fertility problem. ### Drake Fertility Is the Weak Link Pekin genetics carry a fertility cost. In a comparison of pure breeds and crossbreds, the Pekin strain had the lowest egg fertility at 71.3%, compared with 75.9% for Brown Tsaiya and higher values for the crossbreds [2]. Pekin drakes are simply less efficient at natural mating than lighter breeds. This is the reason Pekin breeding rewards careful management more than most backyard duck projects. You are working against the breed's own body type. ## Conditioning Breeders Before the Season ### Weight Management Pekins gain weight easily. An overweight drake cannot mount efficiently, and an overweight hen has more trouble with the physical demands of mating and laying. Manage body condition in the weeks before you start collecting hatching eggs. Feed a breeder-appropriate diet and avoid free-feeding treats that add fat without adding nutrients. Watch the drake especially. A drake that is carrying extra weight will tire quickly and produce fewer successful matings. ### Foot and Leg Checks Pekin weight loads the feet and legs. Before and during the breeding season, examine every breeder's feet and legs for swelling, heat, wounds, and lameness. A lame drake cannot breed. A lame hen cannot comfortably stand for mating. Inspect the undersides of the feet, the hocks, and the leg joints. Any bird showing pain or reluctance to walk should be pulled from the breeding pen and evaluated. Do not leave a limping drake in with the hens, because he will keep trying to mount and will worsen his own injury. ### Feather and Skin Condition on Hens Check the hens' backs and the nape of the neck. Pekin drakes grip the neck feathers during mating. Broken or missing feathers in these areas mean the mating pressure is too high. Reduce the number of drakes or increase the number of hens. ## Nutrition for Breeding Pekins Breeding Pekins need more than maintenance. Laying hens need calcium and protein to produce large eggs and to support shell formation. The research on Pekin eggs shows how much the hen invests in each egg: heavy eggs carry more albumen, and yolk weight is higher in medium and heavy eggs [3]. The embryo draws minerals from the yolk during incubation, and breeder age affects the magnesium, phosphorus, potassium, calcium, copper, and zinc levels in the yolk [4]. The practical points: - Feed a complete breeder or layer ration rather than relying on scraps and scratch. - Provide free-choice [calcium for laying hens](/knowledge/animal-farming/poultry/calcium-phosphorus-management-eggshell-quality), separate from the main ration if your feed does not already include enough. - Keep fresh, clean water available at all times. Ducks need water deep enough to submerge their bills for proper eating and eye health. - Do not let breeders get fat. Obesity is a fertility problem, not a sign of good condition. If you are unsure whether your ration meets the needs of breeding Pekins, ask a veterinarian or an extension poultry specialist. Do not guess with supplements. ## Mating Behavior and Natural Fertility in Pekins ### How Pekin Mating Works Pekin drakes mount from behind and grip the hen's neck. Successful mating requires the drake to balance and align. In a heavy breed, this is physically demanding. A study of Pekin drakes measured correctly aligned mounts as the marker of effective mating behavior, and tracked this over three ages in a breeder setting [9]. Alignment is the whole game. A drake that mounts but does not align does not fertilize. ### Why Pekins Are Poor Natural Maters Three factors combine: 1. Body weight. The drake is heavy and the mechanics of mounting are harder. 2. Leg and foot soundness. Any lameness reduces mounting success. 3. Genetics. The Pekin strain has lower fertility than lighter breeds even under controlled conditions [2]. You cannot change the genetics, but you can manage weight, soundness, and the sex ratio. ### Fertility Duration After Mating Fertility does not end the moment a drake mates a hen. In common ducks, the duration of fertility after artificial insemination averaged 8.1 days in pure breeding, with the maximum interval between insemination and the last fertile egg [10]. Natural mating fertility follows a similar pattern of a fertile window after each successful mating. This matters for egg collection. If you remove a drake, hens may still lay fertile eggs for several days afterward. If you are collecting hatching eggs, keep collecting through that window. ## Artificial Insemination for Pekins ### When to Consider AI Artificial insemination is a legitimate tool for Pekin breeding, especially when natural mating fails. Consider it when: - Drakes are sound and producing semen but cannot mount effectively. - The flock has a history of poor fertility despite a good ratio and good light. - You have a valuable drake and want to use him across many hens. - Hens are being overworked by natural mating and you want to reduce physical pressure. Artificial insemination in ducks is a skilled procedure. It requires handling both the drake and the hen safely, collecting semen without contamination, and depositing it correctly. If you have never done it, work with a veterinarian or an experienced breeder before attempting it on your flock. ### What the Evidence Shows Artificial insemination is well established in duck breeding research. In one study, common duck dams were inseminated with a dose of 175 x 10(6) sperm from either common or Muscovy drakes, and fertility was estimated from candling [10]. Overall fertility from days 2 to 12 after insemination was 61.1% in pure breeding and 42.8% in crossbreeding [10]. The same study found that the age of the dam influenced the duration of fertility, with a longer duration at 40 weeks compared with 50 weeks [10]. The numbers show that AI produces usable fertility in ducks, and that hen age affects how long that fertility lasts. If you use AI, inseminate on a schedule that accounts for the fertile window, and expect older hens to have a shorter window. ### Semen Quality and Light Semen quality responds to light in Pekins. Extended light periods improved semen volume, sperm motility, concentration, viability, and normality in one study, and artificial light improved fertility and hatchability [8]. If you are collecting semen for AI, the same lighting principles that support natural breeding apply. ## Incubation: The 28-Day Pekin Hatch ### Temperature, Humidity, and Turning Pekin eggs incubate for 28 days. The standard set point is 37.5 C (99.5 F). Humidity runs about 55 to 65% during incubation, with higher humidity at hatch. Humidity is not a guess. In a study of Pekin incubation, increasing relative humidity from 55% to 60, 65, and 70% during days 14 to 24 decreased egg weight loss in a stepwise manner regardless of parental age [5]. The lowest embryonic mortality and best results were associated with specific humidity levels in that range [5]. Weight loss is the practical measure. An egg that loses too much water will have a small, stuck duckling. An egg that loses too little will have a large, wet duckling that struggles to hatch. Weigh a sample of eggs before setting and again at day 14 and day 24 to track weight loss. Adjust humidity based on what the eggs are actually doing. Turn the eggs regularly through incubation. Stop turning at the end of day 25 or the start of day 26, when the ducklings internally pip and move into hatch position. Raise humidity for the hatch. ### Egg Size and Hatchability Egg size affects the hatch. Heavy Pekin eggs (over 83 g) had lower hatchability of total and fertile eggs than light and medium eggs, and heavy eggs had thinner shells [3]. On day 25 of incubation, embryo weight was higher in light and heavy eggs than in medium eggs, and the authors concluded that embryo growth is affected by yolk absorption and dry matter accumulation [3]. Select medium-sized eggs for incubation. Set aside the very large and the very small. ### Breeder Age and Egg Quality Eggs from older Pekin breeders have thinner shells and more pores [5], and the mineral content of the yolk shifts with breeder age [4]. In one comparison, eggs from a second-cycle flock at 78 weeks differed from first-cycle eggs at 31 weeks in shell percentage, albumen index, Haugh unit, and duckling growth [6]. If you hatch from older hens, expect more variability and handle the eggs gently. ### Carbon Dioxide During Early Incubation A study tested pumping carbon dioxide into a non-ventilated incubator to hold about 1% concentration through the first 10 days of Pekin incubation, then ventilating normally for the rest [11]. Egg weight loss and embryonic mortality were significantly lower in the carbon dioxide group than in the ventilated control, and hatchability of fertile eggs and duckling hatch weights were significantly higher [11]. Embryonic thyroid hormones and corticosterone were also higher in that group [11]. This is a controlled incubation technique, not a backyard default. It shows that early incubation atmosphere matters for Pekin embryos. If you run a cabinet incubator with adjustable ventilation, follow the manufacturer's guidance and do not improvise gas levels. ### Light During Incubation Providing light during incubation has been studied in Pekins. In a trial using commercial Pekin duck eggs incubated with 12 hours of light and 12 hours of darkness at 250 lux versus complete darkness, light during incubation affected hatchability and hatchling quality measures [12]. The research on incubation lighting is still developing, and the results differ by species and egg type. Treat incubation lighting as an experimental tool rather than a required step. ### Vitamin C Injection In ovo injection of vitamin C has been tested in Pekin duck eggs. Injecting 4 mg on days 12 and 20, or 8 mg on day 20, produced significantly higher hatchability than untreated eggs, with an average difference of 32.5 percentage points, and better results for dead embryos and unhatched chicks [13]. This is a hatchery technique. It requires sterile technique and correct dosing, and it is not something to attempt casually at home. ### Disease and Hatchability Hatchability problems are not always management problems. Duck astrovirus has been detected in breeder duck droppings, breeding eggs, dead embryos, and newly hatched ducklings on a Pekin farm, and the virus was found in dead-in-shell embryos from hatcheries in six provinces [14]. Inoculation experiments caused severe lesions, growth retardation, and embryo mortality, and 8 of 10 inoculated 9-day-old duck embryos failed to hatch, with most dying in the final stage of incubation [14]. The virus appears to transmit both horizontally and vertically and is associated with hatchability problems [14]. If your flock has persistent late-incubation deaths and poor hatch rates despite good incubation management, infectious causes belong on the differential list. This is a situation for a veterinarian, not a home fix. ## Troubleshooting Pekin Fertility Problems Use this table to work through the common causes of poor fertility in a Pekin flock. | Problem | Likely cause | Fix | |--|--|--| | Hens lay well but few eggs are fertile | Too few drakes, or an infertile or lame drake | Confirm the drake is sound and actively mating, adjust ratio toward 1 to 4 | | Fertility drops in fall and winter | Short day length suppresses reproduction | Provide a long light period, roughly 14 to 15 hours, at meaningful intensity | | Fertility low despite long days | Light intensity too low, especially for drakes | Increase brightness, since drakes are more sensitive to low intensity than hens | | Hens have bare backs and broken neck feathers | Too much drake pressure | Reduce drakes or add hens, target 1 to 6 | | Drake mounts but fertility stays low | Poor alignment from weight or leg problems | Manage weight, check feet and legs, consider artificial insemination | | Drakes tire quickly or avoid mating | Overweight drakes | Reduce body condition, feed a measured breeder ration | | Lameness in a breeder | Foot or leg injury from heavy body weight | Remove from the breeding pen, examine, consult a veterinarian | | Large eggs fail to hatch | Heavy eggs have lower hatchability and thinner shells | Set medium eggs, about 76 to 82 g | | Eggs lose too much or too little weight | Incubation humidity wrong | Target 55 to 65% during incubation, higher at hatch, weigh eggs to verify | | Late-incubation deaths with poor hatch | Possible infectious cause such as duck astrovirus | Contact a veterinarian for diagnosis | | Older hens produce fewer fertile eggs | Breeder age affects egg quality and fertility duration | Manage expectations, handle eggs gently, consider younger breeders | ## Step-by-Step: Running a Pekin Breeding Program 1. Select breeders. Choose birds with sound feet and legs, good body condition, and no history of lameness. Aim for medium body size rather than the heaviest birds. 2. Wait for maturity. Do not push drakes into heavy service before about 5 to 7 months of age. 3. Set the light schedule. Provide a long day of roughly 14 to 15 hours at meaningful intensity. Keep it stable. 4. Set the ratio. Start at about one drake to five ducks and adjust based on feather and skin condition. 5. Condition the flock. Feed a breeder ration, manage weight, and check feet and legs weekly. 6. Collect eggs daily. Collect clean eggs, store them cool, and set them fresh. Do not set cracked or heavily soiled eggs. 7. Select egg size. Set medium eggs, roughly 76 to 82 g, and set aside the very large and very small. 8. Incubate at 37.5 C (99.5 F). Hold humidity at 55 to 65%, track egg weight loss, and turn regularly. 9. Prepare for hatch. Stop turning at the end of day 25 or start of day 26, raise humidity, and leave ducklings to dry. 10. Brood the ducklings. Move them to a warm, dry, draft-free brooder and provide appropriate starter feed and water. 11. Record results. Track fertility and hatch rate each set so you can see whether changes help. ## Common Mistakes in Pekin Duck Breeding - Running too many drakes. Pekin drakes are heavy and overmating injures hens. - Running too few drakes. Fertility drops when hens are not mated often enough. - Ignoring light. Short days suppress reproduction, and low intensity hurts drakes more than hens. - Letting breeders get fat. Obesity reduces mating success and overall fertility. - Setting oversized eggs. Heavy Pekin eggs hatch worse than medium eggs. - Guessing at humidity. Weigh eggs to track water loss instead of trusting a dial alone. - Leaving a lame drake in the pen. He will keep mounting and worsen his injury. - Expecting Pekin fertility to match a light breed. The breed has a lower baseline fertility. - Assuming a hatch failure is always incubation error. Infectious causes can cause late deaths. ## Welfare and Safety Points Breeding is physically hard on Pekin ducks, especially the hens. Watch for: - Bare backs and broken neck feathers, which signal overmating. - Lameness or reluctance to walk, which signals foot or leg pain. - Hens hiding from drakes or avoiding the pen. - Drakes that are exhausted, thin, or off feed. Remove any bird showing injury or pain from the breeding pen. Provide clean, dry bedding to protect feet. Provide water deep enough for ducks to submerge their bills and to keep their eyes and nares clean. Handle birds calmly and support the body when lifting, especially heavy drakes. A dropped Pekin can break a leg. ## When to Contact a Veterinarian Contact a veterinarian familiar with poultry if you see: - Persistent lameness, swollen joints, or open wounds on the feet or legs. - A sudden drop in egg production or fertility with no management explanation. - Repeated late-incubation deaths or a hatch rate that stays poor despite correct temperature, humidity, and turning. - Signs of respiratory or neurological disease in the flock. - Any bird that is off feed, lethargic, or losing weight. - A hen with a prolapse, a retained egg, or difficulty laying. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Limitations and When to Contact a Veterinarian Individual flocks vary, and the research summarized here describes group-level patterns rather than what will happen in your specific pen. A single veterinarian visit can resolve questions that no general guide can answer, particularly for lameness, reproductive disease, and unexplained hatch failures. Escalate promptly if a breeder cannot walk normally, if a hen shows signs of egg binding or prolapse, if multiple birds in the flock become ill at once, or if hatchability stays low after you have corrected light, ratio, nutrition, egg selection, and incubation conditions. Persistent embryo deaths in the final days of incubation are a specific red flag for an infectious cause and warrant diagnostic testing rather than more incubation adjustments. ## Frequently Asked Questions ### How old are Pekin ducks when they start breeding? Pekin ducks reach sexual maturity around 5 to 7 months of age. Hormonal markers of reproductive development peak near week 19, with full breeding performance following in the weeks after. ### What is the best drake-to-duck ratio for Pekins? Use about one drake to four to six ducks. A tighter ratio of 1 to 4 gives stronger fertility pressure, while 1 to 6 is gentler on the hens. Watch the hens' backs and necks and adjust. ### Why are my Pekin eggs not fertile? The most common causes are too few drakes, a lame or overweight drake, and short or dim light. Pekin drakes are also genetically less fertile than lighter breeds, so some fertility gap is normal. ### How long does it take to incubate Pekin eggs? Pekin eggs hatch in 28 days. Incubate at 37.5 C (99.5 F) with 55 to 65% humidity, then raise humidity for the hatch. ### Do Pekins need extra light to breed? Yes. Long day length drives Pekin reproduction, and short winter days reduce both eggs laid and fertility. Low light intensity hurts drake fertility more than hen fertility. ### Can I use artificial insemination with Pekin ducks? Yes. Artificial insemination is a valid option when natural mating fails or when you want to reduce physical pressure on hens. It requires proper technique, so learn it from a veterinarian or experienced breeder. ### What egg size should I incubate? Set medium Pekin eggs, roughly 76 to 82 g. Heavy eggs over 83 g have lower hatchability and thinner shells than light and medium eggs. ### Why do my ducklings die late in incubation? Late-incubation deaths can come from incubation problems or from infectious causes. Duck astrovirus has been linked to embryo mortality and hatchability problems in Pekin flocks, so persistent late deaths should be investigated by a veterinarian. ```mermaid flowchart TD A[Select breeders] --> B[Wait for maturity] B --> C[Set light schedule] C --> D[Set drake ratio] D --> E[Condition flock] E --> F[Collect eggs daily] F --> G[Select medium eggs] G --> H[Incubate 28 days] H --> I{Fertility good} I -->|No| J[Check drake and light] J --> D I -->|Yes| K[Prepare for hatch] K --> L[Brood ducklings] ``` ## Related Articles - [Poultry Reproduction: Understanding Breeding and Fertility](/knowledge/animal-farming/poultry/poultry-reproduction-understanding-breeding-and-fertility) - [Duck Care Guide](/knowledge/veterinary-medicine/backyard-poultry/duck-care-guide) - [Cattle Estrus Cycle: Timing and Detection for Breeding](/knowledge/animal-farming/beef-cattle/cattle-estrus-cycle-timing-detection-breeding) - [Goat Breeding Season Planning: Timing, Nutrition, and Health Checks](/knowledge/animal-farming/goats/goat-breeding-season-planning) - [Cervid Breeding Season Management: Timing, Buck-to-Doe Ratios, and Record Keeping](/knowledge/animal-farming/alternative-livestock/cervid-breeding-season-management-timing-ratios-records) - [Winter Care for Backyard Ducks](/knowledge/veterinary-medicine/backyard-poultry/winter-care-backyard-ducks) - [American Pekin Duckling: Care and Growth Guide](/knowledge/veterinary-medicine/backyard-poultry/american-pekin-duckling-care-and-growth-guide) - [Dog Mating: Cycle, Timing, and Breeding Basics](/knowledge/veterinary-medicine/theriogenology/dog-mating-cycle-timing-and-breeding-basics) - [Domestic Cat Breeding: Cycle, Timing, and Care](/knowledge/veterinary-medicine/theriogenology/domestic-cat-breeding-cycle-timing-and-care) ## Sources 1. [Ontogeny of OPN4, OPN5, GnRH and GnIH mRNA Expression in the Posthatch Male and Female Pekin Duck (Anas platyrhynchos domesticus) Suggests OPN4 May Have Additional Functions beyond Reproduction.](https://pubmed.ncbi.nlm.nih.gov/33919914/) 2. [Crossbreeding effects on reproductive traits in two strains of duck (Anas platyrhynchos): brown Tsaiya and Pekin.](https://pubmed.ncbi.nlm.nih.gov/8842464/) 3. [Comparison of hatching egg characteristics, embryo development, yolk absorption, hatch window, and hatchability of Pekin Duck eggs of different weights.](https://pubmed.ncbi.nlm.nih.gov/28938778/) 4. [Effects of breeder age on mineral contents and weight of yolk sac, embryo development, and hatchability in Pekin ducks.](https://pubmed.ncbi.nlm.nih.gov/24570471/) 5. [Effect of incubation humidity and flock age on hatchability traits and posthatch growth in Pekin ducks.](https://pubmed.ncbi.nlm.nih.gov/22912479/) 6. [Effects of hen production cycle and egg weight on egg quality and composition, hatchability, duckling quality, and first-week body weight in Pekin ducks.](https://pubmed.ncbi.nlm.nih.gov/22010253/) 7. [Low light intensity in Pekin duck breeder barns has a greater impact on the fertility of drakes than hens.](https://pubmed.ncbi.nlm.nih.gov/29992329/) 8. [The effect of light stimulus on Pekin ducks in the subtropics. Effect on the reproduction.](https://pubmed.ncbi.nlm.nih.gov/1036217/) 9. [The Impacts of Female Access during Rearing on the Reproductive Behavior and Physiology of Pekin Drakes, and Flock Fertility.](https://pubmed.ncbi.nlm.nih.gov/36359103/) 10. [Duration of fertility and hatchability of the common duck (Anas platyrhynchos) in pure- or crossbreeding with Muscovy drakes (Cairina moschata).](https://pubmed.ncbi.nlm.nih.gov/18359507/) 11. [Effect of carbon dioxide during the early stage of duck egg incubation on hatching characteristics and duckling performance.](https://pubmed.ncbi.nlm.nih.gov/31220515/) 12. [Effect of the combination of white and red LED lighting during incubation on layer, broiler, and Pekin duck hatchability.](https://pubmed.ncbi.nlm.nih.gov/28339779/) 13. [Effect of in ovo injection of vitamin C during incubation on hatchability of chickens and ducks.](https://pubmed.ncbi.nlm.nih.gov/22428314/) 14. [Isolation and detection of duck astrovirus CPH: implications for epidemiology and pathogenicity.](https://pubmed.ncbi.nlm.nih.gov/26814629/)