Breed type and environmental factors such as breeding season may have a significant impact on neonatal weight loss calf size. We followed a total of 236 elective cesarean sections in Belgian Blue (BB) cattle, in which neonatal calves were morphometrically measured (in cm) in the first 72 hours after delivery of the child using a strictly standardized protocol. The influence of the season of birth on each calf measurement was analyzed using a mixed linear regression models, including farm of

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... in as a random effect. Calves born in spring had a longer diagonal length (P = 0.05) (69.7 ± 1.24) than those born in autumn (66.9 ± 1.16). The tibial length of calves born in spring (35.8 ± 0.48) was longer (P> 0.02) than those born in autumn (33.1 ± 0.57) or summer (34.1 ± 0.49). Calves born in autumn have a shorter head diameter (P> 0.02) (12.9 ± 0.23) than those born in summer (12.6 ± 0.29) or winter (13.5 ± 0.22). For all other parameters, no differences were found (P> 0.08). Based on the results of this study, it can be concluded that the birth season influences the morphometrics of neonatal BB calves, with a tendency for spring to be associated with the largest body size. The latter is important to know to avoid dystocia when BB cattle are crossed with other breeds.