Is intersucking in dairy cows the continuation of a habit developed in early life?

Intersucking, i.e., cattle sucking the udder of heifers or cows, is a frequ ent problem in dairy herds and may lead to udder damage, mastitis, milk los s, and culling of breeding animals. Using epidemiological methods, we condu cted an observational cross-sectional study to investigate risk factors for intersucking in Swiss dairy cows. We asked 114 randomly selected dairy far mers about a broad spectrum of environmental factors possibly associated wi th intersucking, such as housing conditions, management, and feeding of cal ves, heifers, and cows. Thirty of the 114 farms were confronted with inters ucking in cows. The mean proportion of intersucking cows per farm was 1.6%. From a total of 3077 cows (Swiss Brown Cattle, Simmental, and Holstein Fri esian) we recorded 49 cows that had performed or were currently intersuckin g. In 69% of these cows, intersucking had been observed as heifers. Using p ath analysis and multivariable stepwise backward logistic and linear regres sion analyses, we revealed that the most important risk factor for intersuc king cows was the presence of intersucking heifers on a farm (odds ratio = 7.8). The results suggest that intersucking in cows is the continuation of a habit that was already established in a cow's subadult life. This emphasi zes the importance of looking not only at the animal's current environmenta l situation but also considering its entire life history for the prevention of behavioral problems.