HED IMPROVEMENT

Wanganui Chronicle, Volume LXXXIII, Issue 19846, 21 May 1927, Page 21 (Supplement)

HED IMPROVEMENT

POINTS OP IMPORTANCE. The largest and most rapid improvement of a herd must rest upon selection; and selection must be based upon (1) record of performance; (2) the body form, and (3) pedigree. Records of performance of each cow in the breed are of very great value in the economic management of a heife. The record is also an indispensable guide in breeding. It is the best indication that one can obtain of a cow’s ability and usefulness, and yet a record »n itself is not sufficient evidence up which to base progeny selection. Th. correlation between a record in one lactation and other lactation periods, of the same cow, is recorded to be about 0.70. This means that cf three records of the same cow (con ection for age having been made), that two will be about the same, while the third will be appreciably aoovc or below. Everyone who has knpt records knows that i vow will not produce the same amount year in and year out. Records of performance are influenced by many factors of management and health. The correlation co-efficient for seven days record with the yearly record in the same lactation is 0.598. and a seven-day record with yearly record in different lactations is 0.462. Thus, it seems that a record of a cow for one lactation is only an indication of what may be expected of her, but by no means a true measure of her life-time ability.