Cross-sucking and mortality in buffalo calves

Cross-sucking can be defined as an oral abnormal behavior expressed by calves and directed towards various body regions of co-specifics. This behavior can result in inflammation or injuries at the prepuce, teats or navel. We aimed to verify whether this behavior is also responsible for an increased mortality risk of calves, which represents a major problem in buffalo farming. Therefore, we assessed the incidence and the potential risk factors for cross-sucking and mortality of calves in 33 buffalo farms. Three trained assessors collected the data through a questionnaire including resource and management measures. These measures were collected using both direct observations and interview with farmers. The farm was used as experimental unit. For each categorical risk factor an ANOVA was performed to assess the association with the outcome variables, whereas for continuous risk factors the association was tested using Pearson correlation coefficients. The mortality rate was defined as the incidence of calves dying from 24 h to the weaning age (83.40 ± 19.93 days; mean ± SD), which occurred at a mean weight of 80.00 ± 18.31 kg. The mean per cent mortality rate was 13.17 ± 8.54, whereas cross-sucking was observed in 90% of farms and the mean per cent incidence was 20.40 ± 25.71. Cross-sucking tended to be positively correlated with the age of separation from the mother (n¼20, r¼0.39, p¼.08) and negatively associated with space allowance (n¼20, r¼-0.38, p¼.11). A positive correlation between cross-sucking and calf mortality rate was observed (n¼20, r¼0.45, p¼.06). Calves fed acidified milk showed a lower mortality rate (8.86 ± 2.18) as compared to dam-rearing (16.32 ± 2.62) and non acidified milk replacer (17.13 ± 2.97; n¼33; p¼.04). The administration of water in buckets after milk feeding also tended to reduce the mortality rate (9.93 ± 2.10) as compared with empty buckets (16.32 ± 2.71) and no buckets (17.22 ± 3.63; n¼33; p¼.10). In conclusion, cross-sucking and mortality appear to be associated and appropriate management strategies should be applied in order to reduce the incidence of cross-sucking and mortality.