INFLUENCE OF THE AGE ON THE DAY OF FIRST CALVING AND THE LENGTH OF CALVING INTERVALS ON THE MILK YIELD OF COWS Journal title: Folia Pomeranae Universitatis Technologiae Stetinensis Agricultura Alimentaria Piscaria et Zootechnica Authors: Paweł BORTACKI, Ryszard KUJAWIAK, Ewa Czerniawska-Piątkowska, Jerzy WÓJCIK, Wilhelm GRZESIAK Subject(s):
