CONICET | Buscador de Institutos y Recursos Humanos

ewline">The objective of this study was to assess the effect of ketosis status onbehavioral activity in transition dairy cows. A total of 1,024 Holsteindairy cows (390 primiparous and 634 multiparous) in 3 commercialdairy herds were enrolled at 14 d before calving until 14 d post-calving.Monthly, a cohort of 20 to 36 cows was enrolled at each farm and electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) were fitedto the hind leg of individual cows to assess their lying time. Holsteinanimals were screened for NEFA at 7 d prepartum (dpp), calcium atcalving (Ca), ketosis (KET) at 7 ± 3 and 14 ± 3 DIM by measuringβ-hydroxybutyrate (BHB) in serum samples, and haptoglobin at 7 ± 3.A case of KET was recorded when lactating cows had serum concentration of BHB ≥1.2 mmol/L. Cases of retained placenta, milk fever,metritis, pneumonia, digestive disorders, and mastitis during the studyperiod were recorded. Lactating cows were allocated into 1 of 4 groups:(1) non-disease (ND, n = 613; cows without KET and any other healthconditions), (2) cows with only KET (n = 152), (3) sick cows experiencing ≥1 health conditions, but without KET (SICK, n = 198), or (4)cows with KET plus at least 1 health condition (KET+H, n = 61). Datawere analyzed using MIXED procedure of SAS. Multiparous cows hadgreater LT (P < 0.0001) compared with primiparous cows, regardless ofhealth status. Cows experiencing KET+H had increased LT (~1 h; P <0.05) compared with ND cows for the fist 6 DIM after parturition. Cowsexperiencing KET, KET+H or SICK had increased NEFA prepartum (P< 0.0001) with greater BCS loss early in lactation (P < 0.0001), reducedCa (P = 0.004), and increased HAPTO (P = 0.0002) compared with NDcows. These results suggest that LT along with energy and Ca balanceare critical for transition cow health