Animal reproduction

Calving Interval

Reduce by

Target 365 days

Gestation of Bull

Breed of Bull

Synchronisation

Increased heat detection - Bull-Kamar-Pedometer

Health

Supplementation of Minerals

Reproductive Efficiency

Number of calves weaned per 100 cows served

Increased by

Hygiene

Colostrum

Disease Management

Breed of Cow

Heat Detection

Fertility

Cow Health

Hormones

Female

Prolactin

Progesterone

Oxytocin

Mainatins Pregnancy

Follicle Stimulating Hormone

Milk Production

Milk Release

Egg Production

Artificial Insemination

Advantages

Disadvantages

Method

AI cow using am/pm rule

Defrost sperm

Observe cow standing in heat

Place straw in catheter

Disease Free

Safer than bull

Cheaper for small farm

Expensive

Hest detection must be good

Poor efficiency

Performance and progeny tested bulls

Labour intensive

Place hand in rectum and clasp cervix

Inject sperm beyond cervix

Target areas in herd

Improve genetics in herd

Gestation

Length of time a cow is in calf

Sheep - 145-150 Days

Cow - 288 Days

Pig 117 Days

Improve by

Short Gestation Bull

Breed

Genetic Superior bulls

Sexed Semen

Lower Methane output

Ovulation

Occurs in Ovary

Release of egg for fertilisation

Animal most fertile

Sexed Semen

Advantages

Higher Heifer Percentage

Less chance of bull calf

Target high genetic mothers in herd

Disadvantage

High cost

Low conception rate

10% chance of bull

Oestrus

Time animal in heat

Cow 18hrs

Pig 48 hrs

click to edit

Signs of oustrus

Male Reproduction

Testicles/Testes – produce sperm (Meiosis) and the hormone testosterone​

Scrotum – holds testicles, regulates temperature​

Sperm must be below body temperature (35°C)​

Epididymis – Maturing and Storing of sperm ​

Vas deferens (Sperm Duct) – Connection tube and forces sperm by peristalsis to urethra​

Urethra – carries sperm & urine to the penis​

Seminal Vesicles –milky (fructose) fluid to nourish sperm and medium to swim​

Prostate Gland – produces alkaline fluid to protect the sperm (Acidic Vagina)​

Cowper’s Gland – fluid cleans urine out of penis​

a chemical messenger that travels to specific organs and prompts a specific response from the organ​

Follicle stimulating hormone (FSH) - promotes sperm production in males. (Pituitary Gland)​

Luteinising hormone (LH) - stimulates testosterone production.​

Testosterone - responsible for the male sex characteristics and increases muscle and bone growth.​

Female

Ovary – produces haploid eggs & hormones​

Oviduct (Fallopian Tube) – narrow passage for egg, site of fertilisation​

Uterine Horn – For litter bearing animals to develop​

Uterus – muscular structure with a spongy lining (called the endometrium) that is enriched with blood vessels to nourish the embryo.​

Cervix – muscle which locks down uterus(between vagina and uterus)​

Vagina – site of copulation (semen deposited) ​

Vulva – external opening of vagina, protects the vagina​

Urethra – carries urine​

Oestrous cycle: A recurring cycle during which a female mammal comes into heat, releasing an egg which is available for fertilisation by the male.​

Duration of oestrous: The length of time during the oestrous cycle in which the female is in heat and an egg is available for fertilisation.​

​Gestation: The period of development in the uterus from conception to birth.

Ovulation: Occurs when the egg is released from the follicle to be fertilized.​

Stands to be mounted​

Mounting other livestock.​

Moistened Vulva​

Bellowing​

Frequent urination​

General nervousness​

Polyoestrous - animals have several oestrous cycles throughout the year.​

Seasonally polyoestrous – ​

  • an animal has several oestrous cycles during a specific time of year.​

-determined by the length of day known as Photoperiod​

  • controlled by Pineal gland which secretes melatonin which triggers breeding

Conception in AI

Depends on

Time of insemination​

Number of sperm inseminated​

Fertility of Females​

Skill of inseminator​

bull

Advantages

Disadvantages

Bulls are aggressive​

Expensive to buy, feed and control.​

Stock bull must be changed to prevent inbreeding​

No Heat Detection​

Labour extensive​

Visible Traits​

Higher Conception Rates​

Heat Detection

Tail Paint : thin strip of paint applied to the top of the cow’s tail​

Kamar Device: Pressure sensitive chamber with red dye, which is activated by standing heat behaviour.​

Vasectomised Bull With A Chin-Ball Harness:​

Activity Meter:​

behavioural patterns ​

temperature, ​

optimum insemination time ​

cow health status​

Factors

Fertility – Low fertility = Longer CI​

BCS – High/Low BCS = Difficulty getting in calf​

Breed/Genetics – Holstein breed puts too much energy in milk not in fertility​

Diet – poor diet = low BCS = Low Cycling Rate​

Health – Cow health will reduce cow cycling​

Mr P Reynolds