The following steps appear to be appropriate to develop such a program:
- Select a suitable breed of dairy animals with consideration given to breed preference, the market for milk, and the value of surplus animals.
- Select or purchase the best animals available, based mainly on their genetic potential for milk production, but with due consideration given to type.
- Decide about the breeding system to be followed.
- Evaluate the strong points and the weak points of the animals in the herd (herd analysis).
- Use sires that offer the greatest promise of improvement in traits of offering, the best potential economic return in the future, based on predicted transmitting ability and reliability of the sire’s proof, but with consideration given to the price of the semen.
Follow a feeding and management program that permits the animals in the herd to fully express their genetic potential.
Animals in the Breeding Program
The dairy animals for which most dairymen strive are usually referred to as `foundation animals’. These animals have following characteristics:
- They have outstanding phenotypes and have transmitted superior genotypes to their progeny
- They are valuable as breeding stock
- They possess most of the qualities of a strong constitution.
- They have high milk yield
Importance of Superior Bulls in Dairy Animals Breeding Program
- The greatest opportunity for genetic improvement in a herd is through the bulls that are selected for use in the breeding.
- The selection differential within each herd can be much higher for bulls than for cow, since bulls are selected from among the outstanding bulls in the entire country, especially when used by means of frozen semen, whereas the cows selected must constitute the majority of those in the single herd.
- The use of a superior sire for several consecutive generations can improve the genotype make up of a herd.
- In each generation, one-half of the remaining portion of original genotypes is replaced by the genes from the superior sires. Therefore, after only 3 generations of breeding to superior sires, seven-eighth of the herd’s genetic makeup comes from the sires and only one-eighth of the original genotype remains.
- For most herds, the greatest potential for genetic improvement is through bulls available for artificial insemination.
- A dairyman who wisely selects bulls to be used in his herd can gain much additional income.
- “Collection of semen from male, processed, evaluated in lab and then transferred to female reproductive tract by artificial means for the purpose of conception is called artificial insemination.” It is most widely accepted technique worldwide for the genetic improvement in animals.
Technique of AI
- First prerequisite is securing animal in crush
- Preparation of operator (inseminator): proper dungaree, gum boots, sleeve lubricated
- Thawing of straw at 37 oC in water bath for 30 seconds.
- After thawing, dry the straw with sterilized tissue paper (indication of thawing is bubble present in straw)
- Hold straw in vertical position with cotton plug in downward direction and PVC end at upper end and cut in vertical direction of PCV end.
- Insert in AI gun and put plastic sheath on it and confirm the union of plastic sheath and gun.
- Make hand cup shaped and insert into rectum.
- Remove faecal material from rectum
- Palpate genital organs and locate cervix
- Introduce AI gun into the vagina at 30-40o By left hand is in rectum make sure that cervix is located and patent.
- Place thumb at external loss and then inseminate by directing AI rod in external oss.
- Place semen in body of uterus
There are three techniques for pregnancy diagnosis:
- Clinical or direct method
- Rectal palpation
- Immunological tests or indirect method
- Hormone (progesterone, estron Sulphate)
- PAS (pregnancy associated substances): early pregnancy factor (EPF), pregnancy associated
- Non-return to estrus
Pregnancy Signs in Rectal Palpation
- Asymmetry of uterine horn
- Position of uterus
- Presence of fetal membrane – allento-chorion (up to 30-90 days these are detected), amniotic vesicle (as early as 35-40 days these are detected), placentomes (formed by fusion of crunkles and cotyledons. After 90 day detectable).
- Presence of concepts/fetus.
- Presence of CL on ovary