Sheep Breeding Season: Ram Management and Ewe Nutrition

Preparing for the sheep breeding season requires deliberate attention to ram fertility, ewe body condition, and the timing of management actions. This article covers the practical steps farmers can take before and during the breeding period, including ram breeding soundness examinations, ewe nutrition targets, breeding management options, and record keeping. The content applies to meat and dairy sheep operations and includes a pre-breeding checklist and ram evaluation form that can be adapted to individual farm conditions.

Why Pre-Breeding Preparation Determines Flock Results

The reproductive performance of a sheep flock is the foundation of its economic viability. In sheep farms, achieving economic and productive efficiency and sustainability goals is directly related with the reproductive management of the animals. Genetically, the male contribution to the offspring is 50%, but in practical terms, there is a greater potential impact of the ram on reproductive results, because one male has the potential to affect a large group of females and therefore greatly affects the entire flock 6. A single ram can settle dozens of ewes in a season, so a subfertile or infertile ram can reduce lamb crop percentages dramatically before the problem becomes apparent.

Selection of males for breeding in the US sheep industry has been traditionally conducted based on phenotypical traits, without a genetic or reproductive evaluation, and without health assessment or records 6. This practice leaves flocks vulnerable to breeding failures that could have been detected with a basic examination. Establishing integrative management practices to select the rams and ram lambs to be used in the breeding season is therefore important. Among these practices are genomic testing, a comprehensive breeding soundness evaluation, and assessment of health status and records of the males before the breeding season, to detect and correct potential issues 6.

The ewe side of the equation is equally important. Maternal diet during gestation can have immediate and long-lasting negative effects on growth and health of offspring, so it is important for producers to ensure they are providing appropriate nutritional management to ewes during breeding and gestation 13. Nutrition represents the major cost for flocks and greatly affects their health, the quality of their products, and their environmental impact 11. High-yielding sheep have very high requirements and dietary intake, requiring nutrient-dense diets and sophisticated nutritional management that should always consider the strong interrelationships among nutrition, immunity, health, reproduction, housing, and farm management 11.

At a Glance: Breeding Season Preparation Overview

The table below summarizes the key management areas, the timing of actions relative to ram turnout, and the primary records farmers should maintain.

Ram Breeding Soundness Evaluation

A breeding soundness examination is the single most valuable tool for identifying rams that are unlikely to settle ewes. The examination should be performed by a veterinarian or an experienced technician and should include a physical examination, genital tract inspection, and semen collection and evaluation.

Physical Examination and Genital Inspection

The physical examination starts with an assessment of overall health and body condition. Rams should be in moderate to good body condition entering the breeding season. Lameness, foot rot, or other mobility issues can prevent a ram from serving ewes effectively, so feet should be inspected and trimmed before breeding.

A thorough breeding soundness evaluation including specific inspection of the male genital tract represents a valuable tool for assessing the reproductive potential of a selected subject and for diagnosing genital disorders. During examination, accurate inspection on penis and prepuce is necessary, since conditions affecting these structures may hamper regular coitus 20. In a retrospective study of 1270 rams undergoing breeding soundness evaluation or admitted for genital disorders, 47 rams presented lesions of the penis and prepuce. The most frequent condition was urolithiasis accounting for over 2% of the cases, followed by lack of the urethral process at 0.39% incidence, and lack of the glans penis and hypospadias at 0.23% of cases. Most of the conditions, 40%, were observed in animals less than 2 years old, suggesting the importance of a careful breeding soundness evaluation in animals at young age 20.

The scrotum and testes should be palpated for symmetry, tone, and the absence of swellings or adhesions. Scrotal circumference is measured and compared against breed and age standards. The epididymides should be examined for enlargement or firmness, which can indicate infection or obstruction.

Semen Collection and Evaluation

Semen collection is performed using an electroejaculator or an artificial vagina. The ejaculate is evaluated for volume, color, and consistency, then examined under a microscope for motility and morphology.

Semen quality can be a sensitive indicator of reproductive disease. In a documented outbreak of Brucella ovis in a Saskatchewan flock, 11 rams underwent 2 breeding soundness evaluations and necropsies. Brucella ovis was isolated from all semen ejaculates and confirmed via whole-genome sequencing. Despite above-threshold scrotal circumferences, all rams were categorized as unsatisfactory due to poor semen quality and leukocytes in semen. Semen motility values in 9 of 11 infected rams and morphologically normal sperm in all infected rams were below the recommended threshold values. Necropsies revealed gross lesions in 7 of 11 rams, with histopathology revealing inflammatory lesions in the epididymides, ductus deferens, ampullae, and seminal vesicles in all rams and in the testes in 9 of 11 rams. Most were subclinical cases 14. Veterinary practitioners can utilize changes in semen quality and the presence of leukocytes as potential indicators of Brucella ovis infection in rams, which may prompt further confirmatory testing 14.

Ram Evaluation Form

Farmers should use a standardized form to record the results of each ram examination. The form should include the following fields:

• Ram identification number or tag
• Breed and age
• Body condition score
• Feet and leg condition
• Scrotal circumference measurement
• Testicular tone and symmetry
• Epididymis palpation findings
• Penis and prepuce inspection findings
• Semen volume and color
• Sperm motility score
• Sperm morphology score
• Presence of leukocytes or other abnormalities
• Overall classification: satisfactory, questionable, or unsatisfactory
• Veterinarian or examiner name and date

Rams classified as unsatisfactory should be re-examined or removed from the breeding group. Rams classified as questionable may benefit from a second examination closer to the breeding date.

Ewe Nutrition Before and During Breeding

Ewe nutrition in the weeks before breeding directly affects ovulation rate and conception. The goal is to have ewes in moderate body condition at breeding, then to provide a brief period of rising nutrition, a practice often called flushing.

Body Condition Scoring

Body condition scoring is a hands-on method for assessing the fat and muscle cover over the loin area of the ewe. Scores typically range from 1, very thin, to 5, very fat. The target condition score at breeding is generally 3 to 3.5 for most breeds and production systems. Ewes that are too thin may have reduced ovulation rates, while ewes that are overly fat may have difficulty lambing and may be less fertile.

Body condition should be assessed 4 to 6 weeks before breeding so there is time to adjust nutrition. Thin ewes should be grouped separately and offered additional feed. Fat ewes should have their energy intake reduced, although care is needed to avoid sudden feed changes.

Flushing

Flushing is the practice of increasing the plane of nutrition for 2 to 3 weeks before and during the first weeks of breeding. The extra energy stimulates an increase in ovulation rate, which can lead to more lambs born per ewe. Flushing is most effective in ewes that are in moderate or thin condition. Ewes that are already fat may not respond to flushing and may be at higher risk of pregnancy toxemia later in gestation.

The response to flushing depends on the forage or feed quality. Farmers should have their feed chemically analyzed for nutrient composition instead of assuming the quality of hay or pasture 13. A survey of New England sheep producers found that the majority, 76.0%, do not have their feed chemically analyzed for nutrient composition, which presents an opportunity for improving feeding management 13. Feed analysis is a low-cost practice that allows farmers to match supplementation to the actual nutrient content of the base ration.

Mineral and Vitamin Supplementation

Ewes should have access to a balanced mineral supplement formulated for sheep. Copper levels must be monitored carefully because sheep are sensitive to copper toxicity. Selenium and vitamin E are important for fertility and lamb survival, and deficiencies should be corrected based on local soil and forage conditions. Iodine is another trace mineral that affects reproduction and should be included in the mineral program.

Nutrition for Ram Lambs and Ewe Lambs

Ram lambs that will be used for breeding need to be grown to adequate size and condition before their first breeding season. They should not be overfed to the point of excessive fat, but they need sufficient energy and protein for growth and semen production. Ewe lambs being bred for the first time also need careful nutritional management to support both their own growth and the demands of pregnancy and lactation.

Breeding Management Options

Farmers have several options for managing the breeding season, ranging from natural mating with no intervention to controlled breeding with synchronization protocols.

Ram to Ewe Ratio

The recommended ram to ewe ratio depends on the age and condition of the rams, the size of the breeding paddock, and whether the ewes are synchronized. A common starting point is 1 mature ram per 30 to 40 ewes, with a lower ratio for ram lambs or for synchronized breeding where many ewes are in estrus at the same time. In a survey of reproductive management in 325 sheep flocks and 119 goat herds in Greece, the median ratio of female to male animals was 22:1 in sheep farms 9. Farmers should adjust the ratio based on their own observations of ram libido and ewe marking.

Breeding Season Length

The length of the breeding season affects the spread of lambing and the labor required at lambing time. A compact breeding season of 2 estrous cycles, about 34 to 40 days, concentrates lambing and allows for more uniform lamb groups. A longer breeding season spreads out lambing but can make management more difficult and can result in a wide range of lamb ages at weaning.

In the Greek survey, the median duration of the mating period was 2 months for adult ewes and 1 month for replacements 9. Farmers should decide on their target breeding season length based on their facilities, labor, and marketing goals.

Estrus Synchronization

Estrus synchronization allows farmers to control the timing of breeding and lambing. Synchronization protocols use hormones to bring ewes into estrus at a predictable time. A meta-analysis of synchronization protocols applied to sheep in Turkey included 24 studies that determined pregnancy rates in 78 different groups consisting of 1934 sheep with five different synchronization protocols between 2001 and 2020. Among the different synchronization methods, the P4 plus PMSG group showed the highest pregnancy rate at 90.37% during the breeding season, and the P4 plus PGF2 alpha group at 69.77% and P4 alone at 68.75% showed the highest pregnancy rates during the non-breeding season. The combination of P4 plus PMSG during the breeding season and progestogen and other hormone applications during the non-breeding season are the most effective methods for estrus synchronization and for achieving the desired pregnancy rates 8.

Progestagens, alone or in combination with luteolysins, are used to control the time of oestrus in sheep, thus permitting better use of artificial insemination, providing synchronised recipients for embryos, and facilitating management strategies 12. Treatment with progestagens and pregnant mare serum gonadotrophin or with gonadotrophin releasing hormone induces breeding activity in sheep before the commencement of the breeding season 12. Implants of melatonin hasten the onset of the breeding season in sheep 12.

Suboptimal fecundity rates remain a major limitation of estrous synchronization protocols in sheep. Research has tested whether GnRH administration could improve ovarian functional outcomes to increase fecundity rates in treated ewes. In one study, GnRH shortened the interval to ovulation and concentrated ovulatory timing in ewes treated with a short-term CIDR plus PGF2 alpha protocol. GnRH increased fecundity compared to CIDR plus eCG and CIDR-only groups 17. Farmers considering synchronization should work with their veterinarian to select a protocol appropriate for their flock and breeding goals.

The Male Effect

The male effect refers to the influence of male pheromones on female reproductive hormones. Introducing a ram to ewes that have been isolated from rams can stimulate the onset of estrus and improve the timing of breeding. The male effect offers several benefits, including improved reproductive management, better timing of breeding, and increased fertility rates. Using natural pheromones provides a non-invasive and sustainable method for managing reproduction, and it can be a cost-effective strategy, reducing the need for expensive hormonal treatments 7.

Research on Awassi ewes examined the influence of pheromones extracted from ram wool on the secretion of luteinizing hormone and progesterone during the breeding season. The experiment was carried out on three equal groups, each consisting of 17 subjects. In one group, 15 ml of the ram wool extract was applied to a piece of gauze and placed in a specially designed mask attached directly to the nose. A second group received buck hair extract, and the third group consisted of Awassi rams. The LH assay was conducted immediately before the treatment and again at 1, 10, and 20 hours post-treatment 7. Farmers can use the male effect by keeping rams separated from ewes for several weeks before breeding, then introducing them at the start of the breeding season.

Health Management Before Breeding

The health status of both rams and ewes affects breeding success. A pre-breeding health program should address vaccination, parasite control, foot care, and biosecurity.

Vaccination

Vaccination schedules should be reviewed with a veterinarian before the breeding season. Ewes should be vaccinated against clostridial diseases and other locally relevant conditions before breeding so they have immunity at lambing time. Rams should be current on their vaccinations as well.

Parasite Control

Internal parasites can reduce fertility and body condition. Fecal egg counts can be used to assess the parasite burden in the flock and to guide deworming decisions. In a study of digestive-tract strongyle fecal egg counts in cattle, sheep, and goats of Sao Tome Island, extensive husbandry was associated with low egg counts in cattle, perhaps because of the low stocking rate and use of anthelmintics. High egg counts were observed in goats, and no influential factor could be related to sheep egg counts 25. Farmers should work with their veterinarian to develop a parasite control program based on local conditions and fecal egg count monitoring.

Foot Care

Foot rot and other foot conditions can cause lameness that prevents rams from serving ewes. Feet should be inspected and trimmed before breeding. Rams with active foot infections should be treated and held out of the breeding group until they are sound.

Biosecurity

New rams introduced to the flock should be quarantined and tested for diseases before being placed with ewes. Brucella ovis is a significant concern because it causes epididymitis and reduced semen quality in rams. The disease can be introduced through the purchase of infected animals. Farmers should know the disease status of the source flock and should consider testing new rams before introduction.

Records and Measurements

Accurate records are essential for evaluating breeding season success and for making management decisions in future years.

Pre-Breeding Records

Before the breeding season, farmers should record the following for each ram:

• Ram identification and age
• Body condition score
• Scrotal circumference
• Semen evaluation results
• Health treatments and dates
• Expected breeding assignment

For each ewe or ewe group, farmers should record:

• Ewe identification and age
• Body condition score
• Lambing history from previous years
• Health treatments and dates
• Breeding group assignment

Breeding Season Records

During the breeding season, farmers should record:

• Ram turnout date
• Ram to ewe ratio
• Raddle or marking harness color changes and dates
• Ram health and libido observations
• Ewe returns to estrus
• Synchronization protocol details if used

Post-Breeding Records

After the breeding season, farmers should record:

• Ram removal date
• Pregnancy diagnosis results
• Expected lambing dates
• Lambing outcomes by ewe and by ram

Pregnancy diagnosis can be performed by ultrasonography. In the Greek survey, pregnancy diagnosis ultrasonographically was performed in 36.6% of sheep farms 9. Real-time ultrasonic scanning has proved to be a reliable method for diagnosing pregnancy in small ruminants 12. Early pregnancy diagnosis allows farmers to identify open ewes and make culling or rebreeding decisions.

Common Failure Patterns in Breeding Management

Several recurring problems can reduce breeding season success. Recognizing these patterns allows farmers to take corrective action.

Ram Failure

The most damaging failure is a ram that is infertile or subfertile. This can go unnoticed for weeks if the ram is serving ewes but not settling them. Signs of ram failure include a high percentage of ewes returning to estrus, a prolonged lambing spread, or a low lambing percentage. A breeding soundness examination before the season is the best protection against this failure.

Inadequate Ram to Ewe Ratio

Too few rams for the number of ewes can result in ewes not being served during their estrus period. This is more likely when ewes are synchronized and many are in estrus at the same time. Farmers should err on the side of more ram power when breeding synchronized ewes or when using ram lambs.

Poor Ewe Condition

Ewes that are too thin at breeding have lower ovulation rates and may not conceive. Ewes that are too fat can have similar problems. Body condition scoring and appropriate nutritional adjustment are the tools for preventing this failure.

Mineral Deficiency

Trace mineral deficiencies can cause poor fertility even when energy and protein are adequate. Selenium, copper, iodine, and zinc are among the minerals that affect reproduction. A veterinarian or nutritionist can help assess the mineral status of the flock.

Disease Introduction

Introducing a diseased ram can spread infection through the ewe flock. Brucella ovis is a particular concern because infected rams may appear normal but have poor semen quality 14. Quarantine and testing of new animals are essential biosecurity measures.

Welfare and Safety Considerations

Breeding season management has direct implications for animal welfare and worker safety.

Ram Handling Safety

Rams can be aggressive, especially during the breeding season. Farmers should use sturdy handling facilities and should never turn their back on a ram. Children and inexperienced handlers should not be in the same pen as breeding rams. Horned rams require extra caution.

Ewe Welfare

Ewes should not be allowed to become excessively thin or fat during the breeding season. Both conditions compromise welfare and productivity. Flushing should be implemented gradually to avoid digestive upset. Water and mineral access should be adequate for the number of ewes in each breeding group.

Ram Welfare

Rams should be monitored for injury and excessive weight loss during the breeding season. Rams that are working hard may lose condition, especially if they are breeding many ewes. Providing supplemental feed to rams during the breeding season can help maintain their condition.

Food Safety

For dairy sheep operations, breeding management affects the timing of lactation and dry periods. Withdrawal periods for any medications used during the breeding season must be observed. Farmers should follow the label instructions for all animal health products and should consult their veterinarian about extra-label use. The U.S. Food and Drug Administration provides animal and veterinary resources for farmers 3.

Professional Escalation Criteria

Farmers should involve a veterinarian or other animal health professional in the following situations:

• A ram fails a breeding soundness examination and the cause is not obvious
• Semen evaluation shows poor motility, poor morphology, or the presence of leukocytes
• A high percentage of ewes return to estrus after breeding
• Ewes are not cycling or are showing weak signs of estrus
• There is suspicion of Brucella ovis or other infectious reproductive disease
• Rams show swelling, pain, or abnormalities of the reproductive tract
• Ewe body condition is difficult to correct with feed adjustments
• Pregnancy rates are below expectations for two consecutive seasons

Veterinary involvement is also recommended when implementing estrus synchronization protocols, because hormone products require careful handling and accurate dosing. The World Organisation for Animal Health provides animal health and welfare guidance that can support veterinary decision making 4.

Breeding for Genetic Improvement

The breeding season is the time when genetic decisions are implemented. Ram selection should consider both fertility and production traits. In low-input production systems, designing and implementing a sound breeding program is essential for sustainably improving livestock productivity. A study of alternative breeding schemes for improvement of local sheep breeds in Northwest Ethiopia evaluated three schemes: one-stage selection at six months or yearling age, and two-stage selections with the first at six months and the second at the yearling age. Each scheme was assessed with three levels of selection proportions, 5%, 10%, and 20%, and four flock sizes. For six-month weight, the annual predicted genetic gains ranged from 0.177 to 0.267 kg for one scheme and 0.157 to 0.233 kg for another. For yearling weight, simulated annual genetic gains were 0.268 to 0.399 kg and 0.265 to 0.398 kg. The annual economic responses estimated for the three schemes ranged from US$0.393 to 0.591, 0.589 to 0.879, and 0.494 to 0.744. The yearling selection scheme yielded 34% and 16% higher economic returns than the other two schemes. Varying the selection proportion significantly influenced the annual selection response, index accuracy, and inbreeding rate. Increasing the flock size had little effect on the genetic progress but significantly reduced the inbreeding rate 16.

Farmers in low-input systems often select rams based on fitness traits and body size. In a study of indigenous Tswana sheep production in Botswana, superior fitness traits of indigenous rams over exotic rams were considered more important when selecting breeding rams in most districts, while in one district rams were mainly selected based on body size. Most farmers kept breeding rams, while those who did not keep rams depended on communal rams for service 10. This information is important in designing successful breeding programs and strategies for the conservation and sustainable utilization of indigenous sheep genetic resources 10.

Seasonal and Breed Considerations

Reproductive management in sheep is dependent on seasonality, which in turn depends on breed and latitude 11. Most sheep breeds are seasonal breeders, with the breeding season triggered by decreasing day length. The timing of the breeding season varies by breed and location. In the Greek survey, the median months of the start of the mating period for adult sheep were May and June, and for ewe lambs and replacement goats these were August and September 9.

Farmers should know the expected breeding season for their breed and location. Some breeds, such as the Power Lake sheep, have four-season estrus and can be kept in captivity 22. Other breeds have a defined seasonal pattern. Out-of-season breeding is assisted by reproductive technologies and management strategies 11.

The reproductive pattern is to a great extent assisted by out-of-season breeding, facilitating genetic improvement schemes, and more recently by advanced reproductive technologies 11. Farmers who want to lamb outside the natural season should work with their veterinarian to select appropriate protocols.

Pre-Breeding Checklist

The following checklist summarizes the key actions farmers should complete before the breeding season begins.

Eight Weeks Before Breeding

• Review breeding goals and expected lambing dates
• Select rams for the breeding season based on records and visual appraisal
• Schedule breeding soundness examinations for all rams
• Assess ewe body condition and group ewes by condition score
• Submit feed samples for nutrient analysis
• Review vaccination and parasite control programs with a veterinarian

Six Weeks Before Breeding

• Complete ram breeding soundness examinations
• Treat any rams that fail the examination or arrange for re-examination
• Begin flushing thin ewes with additional energy
• Trim feet on all rams and ewes as needed
• Order mineral supplements and any synchronization products

Four Weeks Before Breeding

• Administer pre-breeding vaccinations
• Conduct fecal egg counts and treat for parasites as needed
• Confirm ram to ewe ratios for each breeding group
• Prepare breeding records and ram evaluation forms
• Quarantine and test any new rams

Two Weeks Before Breeding

• Recheck ram body condition and feet
• Confirm all health treatments are complete and withdrawal periods have passed
• Assign ewes to breeding groups
• Prepare raddle or marking harnesses
• Review the breeding plan with farm staff

One Week Before Breeding

• Move rams to a location near the ewe flock if using the male effect
• Check all fencing and handling facilities
• Confirm water and mineral access in breeding paddocks
• Finalize the breeding calendar with expected lambing dates

Frequently Asked Questions

When should I conduct a breeding soundness examination on my rams?

A breeding soundness examination should be conducted 4 to 8 weeks before the planned ram turnout date. This timing allows for re-examination of questionable rams and for replacement of rams that fail the examination. The examination should include a physical exam, genital tract inspection, and semen evaluation 6. Rams that are less than 2 years old deserve particular attention because a high proportion of penile and preputial lesions are found in young animals 20.

What is the ideal body condition score for ewes at breeding?

The target body condition score at breeding is generally 3 to 3.5 on a 1 to 5 scale for most breeds and production systems. Ewes should be scored 4 to 6 weeks before breeding so there is time to adjust nutrition. Thin ewes should be grouped separately and offered additional feed, while overly fat ewes should have their energy intake reduced gradually.

How many ewes can one ram breed in a season?

A mature ram can typically breed 30 to 40 ewes in a season, but the ratio depends on the age and condition of the ram, the size of the breeding paddock, and whether ewes are synchronized. A survey of sheep farms in Greece found a median ratio of 22 ewes per ram 9. Ram lambs and synchronized ewes require a lower ratio, often 1 ram per 10 to 20 ewes.

What is flushing and how does it work?

Flushing is the practice of increasing the plane of nutrition for 2 to 3 weeks before and during the first weeks of breeding. The additional energy stimulates an increase in ovulation rate, which can lead to more lambs born per ewe. Flushing is most effective in ewes that are in moderate or thin condition. Ewes that are already fat may not respond to flushing.

Should I have my feed tested before the breeding season?

Yes. Feed testing is a low-cost practice that allows farmers to match supplementation to the actual nutrient content of the base ration. A survey of New England sheep producers found that 76.0% do not have their feed chemically analyzed for nutrient composition, which presents an opportunity for improving feeding management 13. Without a feed test, farmers are guessing at the energy and protein content of their hay and pasture.

What is the male effect and how can I use it?

The male effect refers to the influence of male pheromones on female reproductive hormones. Introducing a ram to ewes that have been isolated from rams can stimulate the onset of estrus and improve the timing of breeding 7. To use the male effect, keep rams separated from ewes for several weeks before breeding, then introduce them at the start of the breeding season.

What should I do if my ewes are not settling after breeding?

If a high percentage of ewes return to estrus after breeding, the first step is to evaluate the rams. Check for lameness, injury, or excessive weight loss. Review the ram to ewe ratio and consider whether the rams are able to serve all the ewes. If the problem persists, involve a veterinarian to examine the rams and to assess the ewes for reproductive disease or nutritional deficiencies.

How do I know if my ram has Brucella ovis?

Brucella ovis infection can be subclinical, meaning infected rams may appear normal. Changes in semen quality and the presence of leukocytes in semen are potential indicators of Brucella ovis infection in rams, which may prompt further confirmatory testing 14. Rams that fail a breeding soundness examination due to poor semen quality should be tested for Brucella ovis, especially if they were purchased from another flock.

Related Farming Guides

• Bull Breeding Soundness and Pre-Season Management
• Ram Breeding Soundness Evaluation for Sheep Producers
• Ram Management Before Breeding Season
• Breeding Season Management for Goats
• Boar Management and Breeding Soundness

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.
• Reproductive Management of Rams and Ram Lambs during the Pre-Breeding Season in US Sheep Farms.. Animals : an open access journal from MDPI, 2021.
• The application of pheromones extracted from Shami goats' male hair and Awassi sheep male wool during the breeding season on LH and Progesterone concentrations in Awassi ewes in Syria.. Open veterinary journal, 2024.
• A meta-analysis of the effects of synchronization protocols applied to sheep in Turkey on pregnancy rates during breeding and non-breeding seasons.. Veterinary medicine and science, 2021.
• Patterns of Reproductive Management in Sheep and Goat Farms in Greece.. Animals : an open access journal from MDPI, 2022.
• Production Characteristics and Management Practices of Indigenous Tswana Sheep in Southern Districts of Botswana.. Animals : an open access journal from MDPI, 2022.
• Review: Managing sheep and goats for sustainable high yield production.. Animal : an international journal of animal bioscience, 2021.
• Reproductive technology in animal production.. Revue scientifique et technique (International Office of Epizootics), 1990.
• Understanding gestational and feed management practices of New England sheep producers.. Translational animal science, 2021.
• Semen quality and pathological lesions in rams naturally infected with &lt,i&gt,Brucella ovis&lt,/i&gt, during an outbreak in Saskatchewan.. 2025.
• Genetic and Environmental Architecture of Ram Fertility Traits: A Review. 2026.
• Genetic and economic efficiencies of alternative breeding schemes for improvement of local breeds in low-input production systems: The case of the Farta sheep in Northwest Ethiopia.. 2025.
• Effects of phase-specific GnRH administration on ovarian functional markers, ovulation timing, and fertility in estrous-synchronized ewes.. 2025.
• Exploration of Small Non-Coding RNAs as Molecular Markers of Ram Sperm Fertility.. 2025.
• A Comparative Review of Fertility and Semen Assessment Techniques in Farm Animals. 2026.
• Lesions of the prepuce and penis in rams: A retrospective study.. 2023.
• Pregnancy Rates, Metabolites and Metabolic Hormones in Bighorn Sheep During and After the Breeding Season. 2016.
• Optimization Model for Captive Breeding of Lake Sheep Based on Space Utilization. Frontiers in Business, Economics and Management, 2023.
• PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF KARAKUL SHEEP UNDER RANGE MANAGEMENT SYSTEM OF BALOCHISTAN, PAKISTAN. Malaysian Animal Husbandry Journal, 2025.
• Diversified livestock management and urban adaptation in the early Shang capital of Zhengzhou: sequential evidence from cattle and sheep tooth enamel at the Zijingshanlu site, China. Archaeological and Anthropological Sciences, 2026.
• Digestive-tract strongyle fecal egg counts in cattle, sheep and goats of Sao Tomé Island in relation to local climate, season and breeding management. 2000.
• Effects of breeding season, nutritional environment and lambing management on lamb production of Southwest Rambouillet ewes. 1988.
• Ownership pattern and management practices of small ruminants in the Gambia - Implications for a breeding programme. Small Ruminant Research, 2001.

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