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
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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