Strategy for Field Progeny Testing Programme
Bulls are considered to be the most important players for carrying out organized breeding services, as the main objectives of breeding like development of foundation stock, increase in productive capacity and reproductive efficiency of the local stock through genetic up gradation can not be achieved without them. They are the reservoirs of the required germplasm or genetic potentialities, which is transmitted to subsequent generations to their offsprings. Once it is established in the offsprings or progenies no extra cost is required to transmit these characters for further inheritance unlike in case of environmental components like the managemental practices, which needs constant investment.
In other hand selection of breeding bulls is an important factor for attaining the desired result. By observing only the body conformation, phenotypic characters or pedigree records, it is not accurate to judge the genetic potentialities of a bull. Progeny Testing therefore, basing on the adequate information gives an accurate estimate of breeding value for assessing the genetic potentialities and is therefore preferred when the animal is used for breeding.
Milk yield is the most important trait considered in selection programmes for dairy cattle, though fat percentage is also measured routinely in some schemes. Since the negative genetic correlation between milk yield and fat percentage may result in the latter declining to low levels, it is usually monitored to eliminate undesirable animals. Bull fertility is important, particularly in AI bulls, while in the female reproductive performance is considered in culling, this being done more for economic reasons than for genetic improvement,
The principal selection method employed is progeny testing where the breeding value of bulls is assessed on the performance of their daughters. The test depends for its efficiency on a large progeny group per sire and on having each sire represented in several herds. AI is necessary to separate environmental from genetic effects. Milk yield records are usually restricted to those from first-calving heifers since this gives the largest group of unselected daughters. Young bulls that enter the progeny test are bred from the best progeny-tested sires and selected dams. Each young bull is used on about 500 cows in milk-recorded herds to ensure that first lactation records of at least 50 daughters are obtained. Matings are done at random to ensure that the dam contribution to progeny genotype is similar for all sire progeny groups.
Though this type of selection programme appears to require a great deal of infrastructural facilities, an efficient testing programme could operate even with a simpler organization if recording is limited to that required for progeny testing. Thus, we will operate the programme which tests 20 CB bulls annually on approximately 50 daughters per bull out of which a minimum of 30 can attain motherhood.
Steps to be adopted
1.Selection of Districts/Sub-Divisions/Blocks.
It is proposed to carry out the programme on pilot basis in selected blocks like Jagatsingpur and Balikuda of Jagatsingpur and Niali and Kantapada of Cuttack district.
2. Selection of Bulls for testing
It is decided to start with 20 Crossbred bulls(10 in first phase) of FSB Cuttack presently donating semen. 2000 doses of semen per bull totaling, 20000 doses is to be used in the districts of Cuttack and Jagatsinghpur. The breedable CB cattle are to be identified for insemination at random by the Chief District Veterinary Officer in a contiguous patch.
3. Orientation Programme
One orientation programme will be conducted at District Head Quarter involving the fields staff.
4. Identification of clusters in each block
The Chief District Veterinary Officers of the concerned districts in consultation with the SDVOs and the VAS or AVAS has to identify some potential pockets for carrying out the test inseminations. The environmental factors like animal population, type of animals, availability of feed resources, farmersâ€™ awareness, holding size etc. may be considered while selecting the clusters.
5. Farmersâ€™ awareness programmes
Awareness for the farmers of the villages under the identified clusters of each block is to be conducted at block level to sensitize them regarding the programme for their involvement and cooperation to make the programme success.
6. Registration / Identification of dams (cows)
The cross bred cows of each cluster are to be registered and identified for test cross through AI with selected bulls. The detailed information of each dam like name of the owner with address, occupation, skin color, age, no. of calvings ,health condition, production status etc are to be recorded for future references.
7. Maintenance of Records
Independent registers for the AI of the selected mothers and follow up there after and the progeny born is to be maintained at VD or LACs for smooth monitoring of he programme.
8. Following up the Inseminated Cows
The follow up of the inseminations are to be taken up regularly on per rectal examination by the concerned Veterinarian. Periodic sexual health control camps are to be conducted to address the reproductive disorders and to increase awareness. The database on the measures taken and insemination follow up is to be maintained properly. The comprehensive health care package for pregnant cows covered under the programme will include Vitamin mineral supplement, Dewormer and FMD vaccination. Special camps are to be conducted for health coverage of the inseminated cows. The monitoring reporting format and other stationeries are to be developed and supplied to the field.
9. Detection and Follow up of the progenies
All the female calves born out of the inseminations are to be detected and registered and marked for their identification with in 25 days of their birth. They are to be regularly followed for recording their growth, body weight gain and optimum maintenance by the LIs. Moreover, the female progenies born out of the insemination will be covered under special health care management upto cow hood (3 years).
10. Organization of Calf Rallies or Shows
Rallies or shows are to be organized by the district authorities with support of the OLRDS for public consciousness.
11. Organization of Infertility Treatment/HI camps
In due course after attainment of the sexual maturity by the female progenies born out of the test cross are to be observed for coming to heat and efforts are to be made by the district authority to bring them into maturity for successful breeding for all the animals.
12. Breeding the female progenies attaining maturity
After attaining maturity the females are suitably out bred through AI with proven bull semen and normal follow up is to be taken out as in case of the mother cows till parturition.
13. Recording of Milk
An educated youth of the village concerned is to be selected and trained for recording the milk yield of F1 mothers after 15 days of calving. The analysis of SNF, Fat and Milk Yield is to be followed as per the test period method for judging the productive capability of the mothers.
14. Estimation of Probable Breeding Value of Sires
Basing on the milk yield, heretability and Progeny per bull the breeding value of each bull is estimated for its potentialities and graded accordingly.