Risk factors associated with the expression of cross-sucking and intersucking in buffaloes

The incidence and the potential risk factors for cross-sucking in calves and intersucking in lactating cows were assessed in 73 buffalo farms located in the area of PDO ‘Mozzarella di Bufala Campana’. Two trained assessors collected the data through a questionnaire including resource and management measures, which were directly taken and asked to the farmer, respectively. The incidences of cross-sucking, intersucking and mortality were also asked to the farmer. The farm was used as experimental unit. For each discrete risk factor, an ANOVA was performed to assess the association with outcome variables (i.e. the incidence of cross-sucking and intersucking), whereas for continuous risk factors the association was tested using Pearson correlation coefficients. Cross-sucking and intersucking were observed in 91% and 45% of the farms, respectively; their mean incidences were 21.9 ± 22.3 and 1.2 ± 1.9 (mean ± SD), respectively. Crosssucking was negatively correlated with the number of calves in the collective pen (n = 34, r= −0.47, p=.01). Furthermore, cross-sucking tended to be positively correlated with calf mortality from 24 h to weaning (n = 34, r=.27, p=.11). The incidence of intersucking was positively correlated with the number of buffalo cows on the farm (n = 73, r=.26, p=.03), the number of lactating buffalo in the pen (n = 73, r = 0.23, p=.04), the percentage of weaned calves cross-sucking (n = 73, r=.29, p=.01), the percentage of heifers and pregnant heifers cross-sucking (n = 73, r=.61, p=.001 and n = 73, r=.52, p=.001; respectively). As expected the percentage of buffalo cows with nose-ring was highly correlated with the incidence of intersucking (n = 73, r = 0.75, p=.001). Moreover, the expression of cross-sucking in the categories of weaned calves, heifers and pregnant heifers induced a higher incidence of intersucking (F1,69=5.5, p=.02, F1,70=28.8, p=.0001 and F1,71=15.5, p=.0002; respectively). We conclude that appropriate management strategies should be implemented in order to reduce the incidence of cross-sucking and intersucking. In addition, the onset of cross-sucking in replacement stock, such as calves and heifers, may favour the development of intersucking in their later lives.