BIHAR ANIMAL SCIENCES UNIVERSITY, PATNA, BIHAR

Transcript:BIHAR ANIMAL SCIENCES UNIVERSITY, PATNA, BIHAR:
BIHAR ANIMAL SCIENCES UNIVERSITY, PATNA, BIHAR Bihar Veterinary College, Patna Speaker: Ramesh Kumar Singh Assistant Professor cum Jr. Scientist Division of Animal Genetics and Breeding Bihar Veterinary College, Patna Aids to Selection Aids to Selection Success of any genetic improvement programmes depends on the accuracy with which breeding value is estimated using information of their own, relatives and combinations of both. Breeding value require recording of data of trait which are included in breeding goal. The information which is used estimate breeding values of trait of breeding goal is called as Selection Criteria or Aids to Selection. TYPE It is the outward confirmation of individuals i.e. the relative proportion, length, breadth and size of different parts of the body that include colour, size and shape of horns, ears etc. Selection depend on type is inevitable when Reliable records of production are not available. Selection is to be made early in life before the availability of production records in order to reduce the cost of culling. When records are available in only one sex as milk yield, males have to be selected only as type. When production records come after the death of the individual e.g. Meat animals. Where productivity is not easily and completely measured as in works and speed. When market demands a particular type that is more profitable. Where beauty is the main consideration as in pet and fancy stock. Production This needs accurate production records for all animals under selection. But the actual records available are varying when comparable with one another. E.g. In dairy cattle milk production in lactation is significantly correlated with lactation period and age of the cow. Dairy cows gradually increase their yield till 6th or 7th lactation and then decline. Similarly in sows, they produce more piglets than gilts, do owing to an age effect on fertility. Hence, it is necessary to standardize all the records to a uniform comparable basis. E.g. In cows – milk production should be adjusted to 305 days, 6 years and 4% fat. Similarly in sows all furrowing records should be adjusted to an equal gilt basis by correction factors. Then only the figures will be comparable. Average of many records will reduce the environmental variations in production. While using record all the available record should be used and not the selected ones. No records should be omitted except when circumstances are so definite that no doubt