Animal Breeding | Biology for Grade 12 PDF Download

Breeding of Cattle :

- Cattle breeders select & mate best type of cattle for a particular purpose.

3-way Cross Breeding

- The breeding of cattle is done by two methods

1. Natural Breeding

a. Random breeding

b. Controlled breeding

2. Artificial breeding

1. Natural breeding - It is further of two types -

a. Random Breeding

- Here some pedigree bulls are kept along with the grazing cows.

- Bulls not selected for breeding are castrated and changed to bullocks. 

b. Controlled breeding -

- In this type of breeding native cows are crossed with superior quality of imported bulls in natural breeding.

- Foreign dairy breeds like Jersey (England), Holstein-Freisian (Holland), Brown Swiss (Switzerland), Ayrshire (Scotland) have been important to give better results.

- Hybrid cows require special environment & yield more milk.

- Hybrid oxen is also comparatively more active & energetic.

Some improved hybrids are : 

– Jersey Sindhi,

– Brown Swiss Sahiwal,

– Ayrshire Sahiwal etc.

2. Artificial Breeding -  The introduction of semen (sperm) in the body (vagina) of females, by artificial means is called ARTIFICIAL INSEMINATION.

- Several cows can be inseminated by semen of a single bull.

- Gestation period of cows is about 9 months & buffaloes is about 10 months.

- Cows give 8-10 calves in complete life span.

- Buffalo in actual sense is called water buffalo (Bubalus bubalis).

- Cow is more adapted for dry conditions.

Super Ovulation & Embryo Transplantation

- Superovulation is a technique where in a cow is made to ovulate more ova by injection of hormones. Lutinizing harmone (LH)

- High quality cow (e.g., more milk producing ) is chosen, & is given hormonal injections to induce super ovulation.

- Fertilization is achieved by artificial insemination

- From this cow 4 to 10 embryos are collected at a time.

- Each of the embryo is transplanted into carrier cow (Surrogate mother).

• By deep freezing (-196⁰C) it is possible to preserve the seven days old foetus for several years and transplanted when required.

• The embryo can be cut into two & Monozygotic twins can be obtained.

• This embryo transplantation technique can also be used for other live stocks like sheep & goat etc.

• Fertility in local breeds of cattle has been overcome through the use of pregnant mare serum gonadotropin. (LH + FSH)

• Sterile & immature cows can be induced to lactate through stilbesterol.