我国规模化牧场奶牛主要产后代谢疾病发病规律调查OA

To elucidate the incidence patterns and influencing factors of major postpartum metabolic diseases in dairy cows on large-scale farms in China,data from 268 671 calving dairy cows on 54 large-scale farms across 12 provinces in three regions of China were collected from January to December 2024.The dataset included 3 170 cases of clinical ketosis,2 913 cases of displaced abomasum,2 334 cases of milk fever,and 18 355 cases of retained placenta.The effects of season,region,parity,days in milk,body condition score(BCS),and gestation length on the occurrence of major postpartum metabolic diseases were statistically analyzed.The results showed that the incidence rates of clinical ketosis,displaced abomasum,milk fever,and retained placenta were 1.18%,1.08%,0.87%,and 6.83%,respectively.Summer(June-August)was the peak season for clinical ketosis and retained placenta,whereas winter(December-February)was the peak season for displaced abomasum and milk fever.The highest incidence rates of clinical ketosis(2.65%)and displaced abomasum(1.32%)were observed in Eastern China,while the highest incidence of retained placenta occurred in Northwestern China(9.07%).Primiparous cows exhibited the lowest incidence rates of all four diseases,with incidence increasing progressively with parity.Clinical ketosis and displaced abomasum occurred mainly during 0-21 days in milk,whereas milk fever and retained placenta were concentrated within 1-2 days after calving.All four diseases showed the highest incidence at BCS≥4.00,with rates of 1.97%,1.79%,1.28%,and 7.29%,respectively.Clinical ketosis had the highest incidence when gestation length was≥280 days(1.45%);displaced abomasum and milk fever peaked at gestation length≥290 days,with incidence rates of 1.45%and 2.45%,respectively;retained placenta showed the highest incidence when gestation length was<270 days(13.46%).These findings indicate that refined prevention and control strategies tailored to seasonal characteristics,regional differences,parity distribution,body condition management,and gestation length may help reduce the incidence of postpartum metabolic diseases in dairy cows,thereby improving animal health and farm economic performance.