title: Effect of age at first calving and milking system on the lactation performance of F1 Bos indicus/Bos taurus crossbreds in Sabah.
abstract: This paper examines the effect of age at first calving and milking system on the overall lactation performance and incidence of lactation failure of 442 F1 Bos indicus/Bos taurus dairy crossbreds in Sabah. The two types of crossbred used in the study were imported F1 Sahiwal x Friesian and locally bred Friesian x Local Indian Dairy. Heifers which did not lactate for at least 120 days or produced less than 20 kg of milk during the fourteenth week of lactation were considered to have failed to establish a lactation. The imported and locally bred heifers recorded failure rates of 23.4 and 21.4% respectively. Three milking systems were examined namely machine milking without calf, machine milking with calf and hand milking. They produced failure rates of 30, 12 and 5.6% respectively. The cows that passed recorded 120 day milk production figures of 878, 1,134 and 1,054 kg respectively. The three age groups of less than 30 months, 30 to 34 months and greater than 34 months recorded failure rates of 37, 22 and 10% respectively. The heifers machine milked without their calf which calved at less than 30 months of age recorded a failure rate of 44% while those which calved at greater than 34 months recorded a failure rate of only 17%.
mesh_terms: D000367:Age Factors; D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D007774:Lactation; D011247:Pregnancy; D011270:Pregnancy, Animal