ChileanJAR

At the La Platina Experimental Station (INlA), Santiago, Chile, from the function proposed by Wood for the lactation curve adjustement, an index to asses the declination of the persistence of cows' lactation curves, was applied. With this index, declination values per unit of time can be expressed as a percentage, as well as in units of milk volume or weight that decrease per unit of time. This characteristic gives to the index a practical feature, by facilitating its comprehension and making possible its use in economical evaluations.