🧬 Breeding Methods and Their Importance

This lesson covers core livestock production and management concepts for practical farm application and exam-oriented preparation.

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Breeding- importance

Class 5 :Breeding- importance of cross breeding. Signs of estrous cycle-Artificial

insemination-merits and demerits.

CROSS BREEDING:

This is mating of animals from the two different established breeds

Eg.: Jersey (b) x Kangayam (c) : Jersey (c) x

Holstein Friesian (b). The cross bred animals

will exhibit the mixture of qualities of both the

parents breeds. The progeny will improve in

production performance and will exhibit

marked disease resistance characteristics of

the native breed and is well adpated to with

stand local climatic condition. 62.5% of exotic blood & 37.5% local blood – ideal .

Jersey x local breed.- F1- 50% ND(c) x J (75%) + 25% ND – F1 50 J 50 ND x 100 J (B) So cross

breeding is also taken up to evolve new breed.

Age at maturity Economic traits

1.Age at 1 [st] calving : Age in days of the cow or buffalo on the date of 1 [st] calving.

2. Lactation Length : Days in milk from the date of calving to the final drying off or

or cessation of milk (305 days)

3. Lactation Yield : Milk yield in Kgs from the date of calving to the date of

drying (corrected to 305 days)

4. Dry period : Days from the date of drying to the date of calving

5. Inter calving period : Days from the date or one calving to the date of next

calving (1 [st],2 [nd] )

6.Peak yield : The highest daily yield in Kgs during lactation period

7. Average Fat% : Average Fat %

8.Service period :The interval between calving and subsequent service resulting

in conception

9.Breeding efficiency : Measured as the No. Services/Conception

Breeding : Production of off springs / young ones

Scientific breeding is needed to get better performance in livestock – milk – meat – wool – Egg

Inbreeding : mating of closely related animals in the same breed such as brother – sister mating

ii. parents off spring mating- when the mates have common ancestors -with in 4 generations

this results in inbreeding

Advantage : A pure line of a particular breed can be maintained

Dis advantage : Loss of vigour, size, production fertility problems

Out breeding : Mating of unrelated animals in the same breed but with no common ancestor for a

minimum of 4-6 generations.

Grading : Grading is a farm of out crossing, where in bulls of a distinct breed are bred on non

descript cows from generation to generation, so that in course of time a populations essentially

resembling the breed from which the Bulls are used.

Non descript cow x Jersey Bull

F1 50% ND + 50% Jersey x Jersey Bull

F2 25% ND + 750% Jersey x Jersey Bull

F3 12.5% ND + 87.5% Jersey x Jersey Bull

After 5-6 generations the off springs will have 96.9 & 98.3% of the hereditary characters of

„Pure Breed‟

So grading is a process by which a few „Pure Breed‟ sires can rather quickly transform

local variety of animals into a „Group‟ resembling the pure breed.

Economic Traits	Col2	Col3	Col4
Particulars	Local	Exotic	Cross breed
Birth weight	20Kg	Jersey – 25-30kg. Friesian – 30-35kg.	Jersey – 25-30kg. Friesian – 30-35kg.
Age at maturity	33 Months	15 months	18-24 months
Age at 1st calving	42 months	24 months	30 months
Lactation yield	12000 Kg.	3000-6000Kg.	2100-2400

Lactation period	180-210 Days	305 days	240 – 270 days
Dry period	90-120 days	60 days	75 days
Inter calving period	18 months	12-13 months	13-14 months

Oestrus cycle

Proestrum: ( 2 days) Period of building up growth of graffian Follicle which helps for the

nourishment of ovum fluid contains hormone called „oestrogen‟. It causes changes in uterus,

blood supply.

Oestrum: ( 1 day) During which the female is ready to receive male.

Metoestrum : ( 4 days) Implantation of the embryo takes place C.L. takes place. Prevents the

growth of graffian follicle thereby arrests oestrus cycle.

Diestrum : ( 14 days)Further development of uterus takes place. If the animal has not

conceived involution of uterus take place.

Symptoms of Heat :

1.Off feed 2. Drop in milk yield 3. restless and excited 4. Bellowing 5. Oedema / swelling of

genitalia 6. frequent utination 7. Transparent mucous discharge 8. cow/buffalo which are in heat

will mount on other animals and allows mounting of other animals.

OPTIMUM TIME FOR CROSSING

Egg/ova from ovary – released about

12-18 hours after the onset of symptoms of

heat. Ovum will survive upto 16 hours

after the release. Sperm live for 12-14

hours.

Morning signs of heat are exhibited – AI

done in the evening : 12 hours delay.

Proestrum : This marks the animal –

coming in heat.

GF – Ovary – growing – increased

Oestrogen

DR GOKUL

Prevents the growth of graffian follicle arrests oestrus cycle.

secretion of follicular fluid – Estradiol - increase No.of Cilia – increased Vascularity of uterus

• increase in thickness ofEpithlial wall of vagina .

The vaginal wall adjustemnt is well filled to prevent possible damage to the wall when coitus

occurs.

Oestrum : This is the period of desire.

„Graffian Follicle‟ – Ripe or very turgid

This period is brought to an end by the rupture of the follicle (or) ovulation. Vulva becomes

swollen. Vulva and Vagina – congested

Met Oestrum : This is the period when the organ returns to normal non congested condition.

During this period the cavity of the GF from which ovum has been expelled becomes

recognized and forms a new structure known as C.L.

1. It prevents the maturation of further graffian follicle

2. It is essential for the implantation of the fertilized egg.

3. It is intimately concerned which the development of mammary gland.

Diestrum :Longest part of estrus cycle Implantation – uterine milk –for the nourishment of the embryo prior to implantation. Absence of pregnancy. – returns to normal and thus the cycle continues.

ARTIFICIAL INSEMINATION. Artificial insemination is the deposition of male reproductive cells (sperm) in the female tract by mechanical means rather than “Natural Service” ADVANTAGES : 1.Increases usefulness of superior sires to extra ordinary degree. 2.Services of Superior Sires are greatly extended.

animals/year but under Artificial Insemination the amount of

semen secreted by the animal can be used to satisfy the

requirements of 1000 animals per year

DILUTION OF SEMEN

Average of Sperm/mL : 1000 million

Total volume of semen/2 ejaculate :6 mL

: (i.e.) 6000 million sperms.

No. of motile Sperms : 90 %

.: Total number of motile sperms : 5400 million.

Expected wastage during processing : 10 %

(i.e.) filling and sealing

Net no.of sperms available : 5400-540= 4860

Minimum No. of sperms required / dose : 30 Million.

.: @ this rate no. of doses that could be prepared : 4860 /30 = 160 doses

So, total no. of doses that can be prepared / week : 160 x 52 weeks = 8320 doses.

Frozen semen required / dose : 1 mL.

3.No need to maintain Breeding Bull.The frozen semen can be stored in the Liquid Nitrogen 196 [0] C.

4.Semen can be quickly and easily transported by air to different continents.

5.Spreading of diseases is absolutely- NIL.

6.Overcomes the difficulty of size and weight between Dam and Sire.

7.Increase the rate of Conception because in the artificial insemination the semen is being

deposited in the mid cervix .

8.Outstanding animals located apart can be mated.

9.Helps in better record keeping.

10.Old and heavy sizes bulls,injured / disabled sires can be used.

MERITS:

1.Semen can be stored in the frozen state, so progeny

can be obtained even after the transfer, WHY even

after death of bull-15-20 years.( atomic, radioactive,

X-ray unit)

2.Semen is expanded and no. of animal can be

crossed.

3.Frozen semen can be transported to destination once in a month from the semen bank.

DISADVANTAGES.

1.Some bulls semen may not freeze well.

2.If inferior bull semen is frozen and used –Extensive damage is caused. 3.Maintenance of frozen semen bank is not economical for a small area of operation. 4.Requires well trained technical personnel‟s and special equipments and hygienic measures are to adapted in preparation. 5.Improper cleaning of instruments and unsanitary condition may lead to lower fertility and may be nucleus for the spreading of diseases.

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Summary Cheat Sheet

Topic	Key Point
Main theme	Importance of breeding, crossbreeding, estrus signs, and artificial insemination
Breeding objective	Improve productivity, fertility, and adaptability of livestock
Crossbreeding use	Combines desirable traits of two breeds and may improve performance
Economic traits	Production, reproduction, growth, and utility traits are major selection targets
Estrus meaning	Period when female accepts the male for mating
Estrus importance	Timely heat detection is essential for successful breeding or AI
AI meaning	Artificial insemination allows use of selected male germplasm without natural mating
Maturity note	Age at maturity affects reproductive planning and farm economics
Main management need	Good breeding needs records, heat observation, and proper timing
Exam trap	Crossbreeding improves performance only when planned; it is not random mixing of breeds