Fertility and milk production in Dutch Friesian cattle.
AbstractFertility data, compiled for the 1st and 2nd breeding periods of 1943 heifers, were related to milk yield in the 1st lactation. Number of AI services required in 1st and 2nd breeding periods were higher (1.39 and 1.44) than for natural service (1.23 and 1.28). No significant relationships were found between milk yield and fertility either within or between herds, Heritabilities were estimated to be 0.31 for milk yield, and 0.08 for number of inseminations necessary for 1st and 2nd pregnancies and for age at 1st calving. JDL. (Abstract retrieved from CAB Abstracts by CABI’s permission)