From information obtained from the herd at La Platina Experimental Station (lNlA), Santiago, Chile, conversion factors, to extend incomplete lactations in Holstein Friesian cows and heifers, were calculated according te the season when lactation starts. The calculated factors for Chile differ from those in the foreign literature, specially for the first 45 days of lactation. The use of foreign factors tend to underestimated the production of Chilean cows; as the lactation period progresses, these differences tend to disappear. |