Diet factors and subclinical laminitis score in lactating cows of smallholder dairy farms in Thailand

The objective of this study was to evaluate the importance of dietary crude protein (CP) content, dietary neutral detergent fiber (NDF) content and feeding regime as well as other factors related to management and demographics on the occurrence of (subclinical) laminitis under practical Thai feeding conditions. Hemorrhage of the white line and the sole, sole ulcer and white-line fissure of all four claws of milking cows (n=119) on 25 farms (selected based on the occurrence of lameness) were macroscopically assessed to calculate the prevalence of subclinical laminitis (SCL) on each farm. Data were collected on farm characteristics, feed and feeding management, floor type and hoof care. Dry matter intake was assessed on each farm and feed ingredients collected and analyzed for dry matter (DM), CP and NDF. No significant differences were found for farm characteristics such as herd size, number of milking cows, parity and body condition scoring between farms with a low (<25%) or a high prevalence (>25%) of SCL. Percentages of DM and CP content of the rations did not differ, whereas mean NDF content in the ration was significantly higher in the low compared to the high prevalence farms. Multiple regression analysis of the data showed that a ration low in NDF content and/or in combination with the separate feeding of roughage and concentrate was associated with a high SCL prevalence. The results suggest that mixing concentrate with a substantial part of the roughage is an important strategy to prevent SCL in smallholder dairy farms under Thai feeding conditions. In addition, the dietary NDF content but not the dietary CP level is associated with SCL prevalence in dairy cows under Thai feeding conditions.