- It eliminates the necessity of keeping one or several bulls/bucks on the farm (depending on herd size). Costs of feeding, housing, separate fencing and labor are eliminated. However, heat detection may be more difficult in the absence of a bull/buck.
- AI can increase the rate of genetic improvement in a herd, as long as superior bulls/bucks are consistently selected. In natural service, the prospective breeder has only the male’s pedigree to rely on, whereas AI males should be progeny tested for their transmitting ability of milk and fat percentage, weight gain, type conformation, etc.
- AI allows breeding of different portions of the herd to different males. Young females may be bred to not yet proven but high potential males, while the majority of the herd can be bred to proven high quality males.
- AI permits breeding of many females on one day when synchronization is practiced. No long drives to top males are involved.
- The danger of transmission of diseases or parasites is greatly reduced.
- The time of breeding can be more carefully regulated, and the owner knows exactly when the female was bred, as opposed to pasture servicing by a male that is allowed to run with the herd
- AI induces good recordkeeping of dates of heat, breeding, pedigrees, etc. This will aid in herd improvements and enable the owner to make better culling decisions.
1.) A heifer is ready for service at 14-18 months
2.) Cows resume heat 38th to 42nd day after calving
3.) It is recommended to serve a cow 60 to 90 days after calving
Calving Interval: Aim at a calf per year per cow
- European-type dairy cows, 8 to 11 months
- European-type beef cows 10 to 15 months
- Zebu-type cows 17 to 27 months.
- Feeding regimes. A Holstein heifer on a recommeded level of nutrition will reach puberty at about 11 months of age, but if raised from birth on 62% of the recommended level of energy, she will be over 20 months of age at puberty. Feeding above recommeded levels will result in earlier puberty. Holstein heifers fed at 146% of the recommeded level reached puberty at an average of 9.2 months of age as compared to 11 months for controls receiving the recommeded diet. Both problems associated with overconditioning and the extra cost of such a diet make overfeeding undersirable.
- High environmental temperature delays puberty.
- Poor health and poor sanitation in rearing facilities. While adverse environments delay puberty and reduce the mature size of animals, weight at puberty is not greatly affected
|Hormonal changes in the peripheral plasma during the estrous cycle of the cow.|
- Mounting other cows or standing still while being mounted by other cows
- Clear discharge from vulva
- Drop in milk yield
- Drop in milk yield
- Dilated and enlarged vulva
- Before the morning milking starts.
- In early afternoon.
- After chores are finished in the evening.
1.) Weaning-to-weaning: Best, since feeding costs and sales are matched
2.) Calving-to-calving: Not good since accounts will not be balanced.
3.) Breeding-to-breeding: Sales and feeding costs will be mismatched.
|Cow reproduction tract|
|Speculum method for inseminating the cow|
|Recto-vaginal method for inseminating the cow|
a) Washing hands
b) Putting on a long plastic glove on the left hand and soaping it up for lubrication
c) Insert left hand into the rectum of the cow
d) Grasp cervix with left hand through rectum;
e) Insert inseminating instrument through vagina;
f) Hold cervix by its posterior end with index and middle fingers and thumb, leaving the other two fingers free to help guide the inseminating instrument;
g) Guide the instrument into the opening of cervix and manipulate the cervix in all directions to pass the instrument through cervix;
h) Move the fingers and thumb forward so that the manipulation is taking place just forward to the end of the instrument;
i) Stop the instrument as soon as it reaches the back end of the cervix, and do not withdraw the instrument, especially when the cow urinates;
j) Deposit semen slowly for 5 seconds.
- Retained placenta (link to reproductive problems please)
- Poor feeding (also mineral deficiency – link to animal nutrition)
- Breeding diseases (link to reproductive problems please)
- Difficult calving
1. The dry period (weaning to mating) – approximately 3 months
2. The pregnancy period (mating to kidding) – approximately 5 months
3. The lactation period (kidding to weaning) – until 2 months into next pregnancy
1. Low doe and kid mortality
2. The kids are given a weight advantage at birth
3. Milk flow in the doe is increased causing a greater live weight gain in the kid and thus a heavier live weight of adult stock.
It is emphasised that during this period there should be no drastic changes of feed. Any change must be done gradually in order to allow adaptation. Water and mineral licks should be provided at all times.
|Doe’s reproductive tract|
|Hormonal changes in the peripheral plasma during the estrous cycle of the doe|
Does should not be inseminated based solely on secondary signs of heat. Does should be observed in a place that allows free mingling but also allows observation of all does at the same time. Optimum reproductive performance is dependent on proper nutrition, including mineral nutrition. Deficiencies in trace minerals such as selenium, copper, zinc and manganese can result in lack of libido (silent heats), reduced conception rates, early embryo deaths, and other reproductive failures.
P.O.Box 76478-00508, Nairobi, Kenya
Ndama Place, Kabarnet Road,
Tel: +254 (20) 3871692
i. +254 (20) 3868088
Mobile: +254 722 692005
C/o High Chem Veterinary Ltd
Tel +254 (20) 530744
2nd floor, Mobil Plaza, Muthaiga Road, Nairobi
Mobile: +254 721 095 555
Longonot Place, Ground floor Kijabe Street,
P.O.Box 7940-00100, Nairobi, Kenya
Tel: +254 (20) 2245313/4
Mobile: +254 722 509906
Mospa Building, Uganda Rd, Eldoret
P.O.Box 1320, Eldoret, Kenya
Tel: +254 (20) 2027173
Mobile: 0720 872 397
Mobile: +254 722685348
Please link to http://www.d-gak.org;
For Both Goats and Cows, Animal Breeding specialist
P.O.Box 17812-00100 Nairobi
Mobile: +254 732921219
- Barbara Rischkowsky & Dafydd Pilling (editors). (2007). The State of the World’s Animal Genetic Resources for Food and Agriculture. FAO Rome.
- Blowey, R.W. (1986). A Veterinary book for dairy farmers: Farming press limited Wharfedale road, Ipswich, Suffolk IPI 4LG
- Central Artificial Insemination Service: http://www.cais.co.ke
- Force, B. (1999). Where there is no Vet. CTA, Wageningen, The Netherlands. ISBN 978-0333-58899-4.
MEDILINK LAB & SURGICALS LTD
Next to Nakumatt,
P.O. Box 2180-00200,
Nairobi – Kenya.