DAVE, A. D.PATEL, KISHANBHAI N.2018-04-202018-04-201987http://krishikosh.egranth.ac.in/handle/1/5810044237Lactation records 214 of Jersey x Kankrej(F1), Holstein Friesian x Kankrej(F1) and weaned herd of Kankrej cows of Livestock Research Station, Gujarat Agricultural University, Anand were studied for the period from April, 1979 to July, 1985.The age at first calving, service period, lactation yield, 300 days’ yield, lactation period, dry period, daily and weekly peak yields and persistency were significantly (P<0.01)influenced by the breed groups. The JK cows had the shortest (126.56 days) service period followed by Kankrej (177.30 days) and HK (185.23 days) cows while the HK cows had the hishest lactation milk yield (4,261.79 kg) followed by JK(2,699.89 kg) and Kankrej (2,274.17 kg cows.enLIVESTOCK PRODUCTIONA STUDYThesis