Age at calving in heifers and level of milk production during gestation in cows are associated with the birth size of Holstein calves

摘要: The objective of the present study was to evaluate environmental and dam factors associated with birth size Holstein calves. Data 1,594 births from dairy herds in Belgium Germany were analyzed a retrospective cross-sectional study. Immediately after birth, weight calves measured. On next day, heart girth (HG), withers height, diagonal length dams Parity, body condition score, gestation (GL), age at calving recorded for all dams. For cows, days open, lactation length, dry period, interval also calculated. magnitude shape that took place during quantified using MilkBot model based on monthly milk weights. Using same procedure, cumulative production conception drying off (MGEST) After descriptive analyses, mixed models used identify are significantly (most consistent measure birth) born both heifers cows. Of variables offered offspring (n=540), calf sex, season calving, GL, HG, significant. mean estimated be 41.3±1.01kg. In comparison old (25.5 37.3mo; n=99) heifers, 2.75, 3.29, 2.35kg heavier when very young (20.3 <22mo; n=98), (22 <23.5mo; n=145), standard aged (23.5 <25.5mo; n=198) respectively. cows (n=1,054), parity, MGEST 44.1±0.99kg. having an identical 0.97 1.11kg higher low (1,400 <5,400kg) high (6,500 <7,200) MGEST, respectively, compared (7,200 11,600kg) MGEST. decisive effects levels their may provide basis developing managerial interventions improve long-term health productivity offspring.