K15 Flashcards
Breeding programme
- methods: Artificial Insemination (AI) and natural mating
- commonly employed in several fields where humans wish to change the characteristics of their animals’ offspring through careful selection of breeding partners
- important for higher quality of milk production
Objectives of Breeding Programme
- ensure the sustainability of milk production of the herd
- maximise the milk production in each cow
- synchronise the production time in dairy cattle
What are the common dairy breed?
Holstein
brown swiss
guernsey
jersey
ayrshire
shorthorn
What are the aspects included in breeding programme
- consideration in breeding
- production cycle
- breeding methods
- causes of infertility
- reproductive diseases
Considerations in breeding for MILK PRODUCTION
- Selecting the best cow/heifers
- mature cow who has already calved
- pregnant cow with many offspring before
- pregnant heifer and have her first calf soon - Selecting the best bull (semen)
- Achieving the best milk production efficiency
What are the characteristics of good dairy cow?
- Produce a large quantity of high value output (milk)
- Good health status
- Good longevity
- Easy to manage
- Good conformation
What are breed characteristic of high yielding dairy cows?
- Feminine head
- Wedge shaped appearance of the body
- Bright eyes with lean neck
- Good feet and strong legs
- Udder well attachged to the abdomen
- All 4 quarters of the udder well demarcated with well placed teats
Explain the production cycle
- Calf
- Weaned in 6-8 weeks old
- Breeding in 15 months old
- Calving in 24 months old
- Lactating in 305 days
- Breeding again after 2 months of lactation
- Dry period for 60 days
- Calving again 9 months after
What is the maturity age?
Puberty around 6-16m
40-45% of adult weight (200kg)
Mated or AI at 15 months old
Left to grow for a longer time if not yer reached targeted weight
Oestrus cycle
- Marked by the reoccurrence of oestrus when ovulation occurs
- Synchronise oestrus cycle to achieve synchronised calving
- Using hormone implant (progesterone) - in the ear, intra-vaginally or by injection
- Increase milk production but also increased risk of mastitis and lameness
Explain the stages of oestrus cycle
- Proestrus (D18-21)- Progesterone declines with regression of CL, oestrogen increases, secondary signs of oestrus occur
- Oestrus (D0)- Sexually receptive, initiated by elevation in oestrogen, High uterine motility
- Metoestrus (D1-5)- New CL form, progesterone rise, Metoestrus bleeding may occur in 90% of heifers and less than 45% of cows
- Dioestrus (D6-17)- CL reaches maximum size & function, High levels of progesterone, IF Not pregnant - CL regresses & progesterone decreases, IF Pregnant – CL does not regress & progesterone level remain high
What is the signs of oestrus period
Primary sign - standing to be mounted
Secondary sign- vary in duration and intensity (mounting of other coes/ chin resting/ clear mucus discharge/ swollen, moist and red vulva/ high level of activity/ very vocal and bellow frequently)
Explain the mating
- ovulation occurs 25-32h after onset of standing oestrus
- sperm must stay in reproductive tract for at least 6h to fertelise the egg to allow capacitation occur
- sperm viability is 18-24 h
- ovulated egg remain fertilisable longer (10-20 hours) than they remain capable of being fertilised and developing into normal embryo (8-10 hours)
- cow should be inseminated during last half of standing oestrus
Explain gestation and parturition period
- Majority carry a single calf
- Pregnancy lasts an average of 280-285 days (9 months)
- Calves around 24 months if impregnated at 15 months
- Heifer continue to grow during this period (reach full size at 4 years old)
- Milk production start before delivering calf – provide colostrum for the calf
Explai the lactation period
- Start milk production at 24 months old
- Naturally (without human intervention) – last from calving time to time of drying off (10-12 months)
Explain the dry period
- Cow is not milked – stop milk production
- Last around 60 days before being calved
Explain AI breeding methods
- Semen with living sperms are collected from male and manually introduced into female reproductive tract at proper time with help of instruments.
- Widely used for breeding dairy cows for sustainable productions.
1. collection of semen
2. insertion of semen into cow’s vagina
Explain the process of collection of semen
- Artificial vagina is secured in service crate
- Artificial vagina is assembled at 45° angle from the direction of penis
- Sheath of bull is graphed by operator when the bull mounts. directing penis into artificial vagina folloed by a thrust to ejaculate
- Artificial vagina is taken off from the penis after dismounting
- Water from jacket is drained allowing ejaculate to flow through the collection tube
- Semen collection tube is detached from the cone.
Insertion of semen
- Firmly position cow- relaxed and appropriately restrained with space for food and water
- Thaw the straw- 35℃of water/ removed from flask with forceps/ only thaw one straw at a time
- Prepare the cow- vulva is cleaned with paper towel/ Handler wears an arm length glove and inserts arm inside vulva/ Any excess dung is removed/ If rectum becomes distended, process is reserved for awhile
- Find the cervix- landmark and located befor inserting the gun/ pelvic rim
- Insert AI gun- Use elbow to exert downward pressure on vagina to part the lips of vulva/ guide the AI gun to engaged in the cervix and pass it over the AI gun
- Line up AI gun- AI gun is lined up through the cervix and passed through the canal manipulating the cervix back over the tip of the gun.
- Reach the cervix- Semen is deposited into the short chamber of the uterine horns on the other side of the cervix/ deposit the semen slowly
- Maintain equipment- Do not reuse sheaths/ can increase risk of disease spread and reduce
pregnancy rates.
What are the advantages of AI in dairy farms
Cost saving- avoild maintenance of breeding bull for a herd
Increase conception rates- can produce calves and milk
Disease control- Prevents genital disease: brucellosis
What are disadvantages of AI in dairy farm
Fertility problem- improper sanitisation
Extreme invasive- cause stress in cows affect milk production
Complicated procedure- requires specific process : storing semen and inseminate the cows
Explain natural breeding
Random mating that occurs between two individuals of the same species.
- Identify oestrus period or precopulatory behaviour : smelling of urine/ swelling and reddening of vulva
- Breed the cattle- pulling the bull together with cow
- Monitor bulls and cows during breedin season- cows with tails being held out when walking
- Pull out the bull after 2m to ensure all cows get 3-4 chances of being covered
