Livestock Reproduction

Livestock Breeding

🐄🐑🐖 Livestock Breeding

🎯 Learning Outcomes

✅ Describe the reproductive systems of male and female livestock.
✅ Identify signs of heat and key stages of the reproductive cycle.
✅ Explain common breeding techniques used in pigs, sheep, beef and dairy cattle.
✅ Monitor and manage animals before, during and after parturition.
✅ Apply principles of genetics and selection to improve herd or flock performance.

🧬 1. Introduction to Livestock Breeding

Breeding is the foundation of livestock production. Each animal born is the result of careful planning, observation, and sometimes advanced reproductive technology. A successful breeding program combines knowledge of animal anatomy, genetics, and management practices.

Modern breeders aim to:

Improve productivity such as milk yield, growth rate, or litter size.
Maintain or improve herd and flock health and fertility.
Use resources efficiently, including feed, space, and labour.

Species	Typical Breeding Goal
🐄 Dairy Cattle	High milk yield and fertility
🐄 Beef Cattle	Growth rate, feed efficiency, carcass quality
🐑 Sheep	Prolific lambing, maternal ability, meat quality
🐖 Pigs	Large litter size, uniform growth, feed efficiency

💡 Did You Know? A single AI bull in the dairy sector can sire over 50,000 calves worldwide through semen collection!

⚙️ 2. The Reproductive Systems

Understanding the reproductive anatomy of livestock is critical for effective breeding and monitoring. Differences in reproductive structures influence fertility, AI procedures, and management practices.

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♀️ Female Reproductive System

The female reproductive system produces eggs, supports fertilisation, gestation, and gives birth. Proper functioning of these organs determines conception rates and overall reproductive success.

Part	Function	Example Across Species
Ovaries	Produce eggs and hormones	Sows release multiple eggs per cycle; cows usually one
Oviducts	Site of fertilisation	Where sperm meets egg
Uterus	Foetus development	Uterine horns in pigs and sheep; single chamber in cows
Cervix	Barrier and passage	Very firm in cattle — AI requires skill!
Vagina/Vulva	Birth and mating passage	Visual heat signs often seen here (swelling, discharge)

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♂️ Male Reproductive System

The male reproductive system produces, stores, and delivers sperm. Sperm quality, quantity, and delivery mechanism affect fertility and successful conception.

Part	Function	Example Across Species
Testes	Produce sperm and testosterone	Rams have high sperm output per kg bodyweight
Epididymis	Stores and matures sperm	Bulls need 6–8 weeks to produce mature sperm
Vas deferens	Transports sperm	Common site for vasectomy in teaser males
Penis	Deposits semen	Boar penis corkscrew-shaped to fit sow cervix

💡 Did You Know? Boars produce up to 300 ml of semen per ejaculate — compared to just 5 ml in bulls!

🔄 3. The Reproductive Cycle

The reproductive cycle includes heat, mating, gestation, birth, lactation, and weaning. Each stage requires careful management to optimise fertility and offspring survival.

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Stage	Description	Cattle	Sheep	Pigs
Oestrus (Heat)	Female receptive to mating	12–24 hrs	24–36 hrs	2–3 days
Service (Mating/AI)	Egg fertilised by sperm	AI or bull	Natural or AI	Usually AI
Gestation	Pregnancy period	283 days	147 days	115 days (“3 months, 3 weeks, 3 days”)
Parturition	Birth of offspring	Calving	Lambing	Farrowing
Lactation	Milk production	10 months	3 months	3–4 weeks
Weaning	Separation from dam	6–8 weeks	12–16 weeks	28 days

📘 Duty Link:
Duty 13 & 4: Monitoring and assisting animals before, during, and after parturition.
S12: Caring for livestock throughout the reproductive cycle.

🐄 4. Managing Animals Pre-, During & Post-Parturition

Effective management during each stage of parturition ensures offspring survival and maternal health. Monitoring body condition, housing, hygiene, and assistance during birth are key.

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Stage	Key Management	Example
Pre-Parturition	Check body condition, prepare clean housing	Heavily pregnant sows moved to farrowing crates 5–7 days before due date
During Parturition	Observe discreetly; assist only when necessary	Sheep may need help with twin lambs or malpresentation
Post-Parturition	Ensure colostrum intake and hygiene	Calves require 4L of colostrum within 6 hours; lambs within 1 hour

💡 Did You Know? Colostrum provides antibodies — newborns have no natural immunity until they receive it.

🧪 5. Livestock Breeding Techniques

5.1 Selective Breeding

Selective breeding uses animals with desirable traits to improve future generations. This can improve milk production, growth rate, litter size, or maternal ability.

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Species	Selection Traits	Outcome
Dairy Cattle	Milk yield, udder health	Increased milk solids
Beef Cattle	Growth rate, carcass quality	Higher meat yield
Sheep	Prolificacy, mothering ability	More lambs reared per ewe
Pigs	Litter size, lean meat ratio	Larger, faster-growing litters

💡 Did You Know? In UK dairy herds, genetic progress now adds over 100 litres per cow per year to average milk yield.

5.2 Artificial Insemination (AI)

AI allows controlled breeding using selected sires without moving animals. This improves genetics, disease control, and herd management.

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Technique	Purpose	Used In	Advantages
Standard AI	Controlled mating	Cattle, pigs, sheep	Access to top sires, disease control
Fertility Plus	Boost ovulation & conception	Dairy cattle	Improves pregnancy rates
Synchronisation	Aligns heat cycles	Beef, sheep	Easier management of breeding groups
Sexed Semen	Choose male/female offspring	Dairy & beef	Heifers for dairy, bulls for beef

💡 Did You Know? Sexed semen is now >90% accurate in producing the chosen gender.

🧬 6. Genetics and Breeding Improvement

Genetics play a major role in herd performance. Understanding inheritance, hybrid vigour, and selection helps maximise production and health.

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6.1 Pure Breeds and Crossbreeds

System	Example	Advantage
Pure Breeding	Holstein × Holstein	Consistency in type and performance
Crossbreeding	Texel × Mule	Hybrid vigour, better lamb growth
Composite Breeds	Stabiliser cattle	Balanced fertility, growth, milk

💡 Did You Know? Crossbred ewes often live longer and wean heavier lambs due to hybrid vigour.

6.2 Genes and Inheritance

Traits can be dominant, recessive, homozygous, or heterozygous. Breeders use this knowledge to predict and improve offspring performance.

Gene Type	Effect	Example
Dominant	Always expressed	Polled (hornless) cattle
Recessive	Only expressed when inherited from both parents	Certain coat colours in pigs
Homozygous	Both alleles same	Predictable traits
Heterozygous	Alleles differ	More genetic diversity

📘 Fact Box: In sheep, the Booroola gene increases ovulation — leading to higher litter size.

6.3 Line Breeding & Composite Formation

Line breeding maintains specific family traits, while composite breeds blend multiple lines to balance fertility, growth, and milk traits.

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6.4 Selecting Breeding Stock

Selection is based on genetic merit, physical assessment, health, fertility, and temperament.

Criteria	Tools/Measures	Examples
Genetic merit	EBV, PTA	Bulls rated for fertility, growth, milk yield
Physical assessment	Linear scoring	Teat placement, leg structure
Health & fertility	Records, vet checks	Ewes scanned for barrenness, boars semen-tested
Temperament	Observation	Docile bulls and sows safer to handle

💡 Did You Know? In the UK, EBVs can predict up to 70% of an animal’s genetic potential before it’s born.

6.5 Culling

Removing animals that don’t meet breeding or performance targets ensures herd health and efficiency.

Species	Common Culling Reasons
Dairy Cows	Mastitis, infertility
Beef Cows	Poor mothering, low growth
Sheep	Teeth problems, barren
Pigs	Lameness, poor litter size

🔎 7. Detecting Heat

Accurate heat detection is essential for successful AI and natural mating. Signs vary between species and can be enhanced with technology.

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Species	Signs of Oestrus (Heat)	Detection Tools
Dairy Cows	Restless, mounts others, clear mucus	Heat detection collars, chalk tail paint
Beef Cows	Group behaviour changes	Teaser bulls
Sheep	Seeks ram, tail wagging	Raddle harness on ram
Pigs	Red swollen vulva, rigid stance when pressure applied	Teaser boar, back-pressure test

💡 Did You Know? In sows, ovulation occurs about 40 hours after heat starts — timing is critical for AI success!

🧫 8. Advanced Breeding Technologies

Advanced technologies like embryo transfer, genomics, and infertility treatments allow faster genetic improvement and higher reproductive efficiency.

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Technology	Description	Species Used In	Benefit
Embryo Transfer (ET)	Collecting embryos from elite females to implant in others	Cattle, sheep	Rapid genetic gain
Multiple Ovulation	Hormones trigger several eggs	Dairy cattle	Increases embryo output
Genomics	DNA analysis to predict performance	All major species	Early selection accuracy
Infertility Treatments	Hormone or diet-based	All	Restores breeding efficiency

💡 Did You Know? A single top Holstein cow can have over 100 offspring via embryo transfer!

📊 9. Recording and Performance Data

Recording data ensures informed breeding decisions, tracks performance, and monitors herd health.

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Record Type	Purpose	Example
Service Records	Track matings	AI date, bull used
Pregnancy Records	Check conception	Scanning results
Parturition Data	Manage calving/lambing	Birth weights
Performance Data	Monitor output	Milk yield, growth rates
Culling Records	Health planning	Reasons for removal

📘 Duty Link: Connects to Duty 4, Duty 14, and S4 – implementing and monitoring breeding plans.

🧩 10. Summary

Livestock breeding combines art and science. Success depends on understanding anatomy, genetics, reproduction, and management practices. Observation and data-driven tools maximise productivity and animal welfare. Each breeding decision shapes the future of the herd or flock.

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🧠 Knowledge Check

List three signs of heat in dairy cattle.
What is hybrid vigour, and why is it important?
Name one advantage of using synchronised AI in sheep.
What are EBVs used for?
Explain the importance of colostrum in newborns.

🧤 Practical Tasks

Observe and record heat detection signs on-farm.
Compare EBV data for three AI bulls.
Identify cows or sows approaching parturition and plan pre-birth management.
Visit a local farm using AI or ET technology and discuss benefits.