Animal Health 1: Metabolic Health and Disease

摘要

Body condition score (BCS) is a quick, cheap and reliable tool thathelps determine fat reserves. BCS at calving and changes in BCS aftercalving have been consistently associated with milk yield, diseases,and fertility in dairy cows, yet, the dynamics of BCS during the dryperiod has been less studied. The objective was to assess the change inBCS within the far-off (dryoff to −21 d prepartum) and close-up (−21d prepartum to calving) and its association with postpartum diseases.The study analyzed 22,000 lactations from 28 dairies from Argentina.BCS was assessed with a scale of a 1/4 unit from 1 (emaciated) to 5(obese). BCS was carried out by 2 of the authors creating 4 groups.G1: cows that maintained or gained BCS during far-off and close-up;G2: cows that maintained or gained BCS during far-off and lost BCSduring close-up; G3: cows that lost BCS during far-off and maintained orgained BCS during close-up; G4: cows that lost BCS during far-off andclose-up. Diseases were compared among groups by conducting logisticregression. Dependent variable was the incidence of the disease (yes,no). Three models were run, comparing G1 vs G2, G1 vs G3, and G1 vsG4, correcting for year, BCS at calving, lactation and farm. Group wasnot associated with the incidence of milk fever and lameness; however,cows gaining or maintaining BCS across the entire dry period (G1) wereless likely to experience RFM, metritis, subclinical ketosis (BHB ≥1.2mmol/L), clinical mastitis, and culling than cows losing BCS duringthe close-up period (G1 vs. G2; and G1 vs. G4; Table 1). The impact oflosses of BCS during the far-off period was less dramatic (G1 vs. G3)than during the close-up period.