Frequency and severity of neonatal calf diarrhea cases treated with a standard veterinary hospital protocol do not affect heifer reproduction performance and first lactation production

Neonatal calf diarrhea (NCD) is the most critical disease in preweaning calves and causes great economic losses. We evaluated the long-term effects of NCD on reproduction and production outcomes during the first lactation. We also analyzed the effect of the severity of the largest clinicopathologic abnormalities observed during NCD on subsequent first production and reproduction performance. Clinical and laboratory findings were reviewed in 88 Holstein Friesian diarrheic calves over a 4-year period. Calves were treated according to a fluid therapy protocol, and then discharged from the hospital in a healthy state. For each animal, days in milk (DIM), 305-day milk yield, milk fat and protein production, and age at first calving (AFC) were recorded. For the control group, we examined non-hospitalized heifers (n = 85) of the same age and from the same herd without a clinical history of NCD. Generalized linear model analysis showed that there were no significant differences between the two groups in relation to DIM (P = 0.740), 305-d milk yield (P = 0.883), fat (P = 0.660) and protein (P = 0.582) production, and AFC (P = 0.879). No effect of the severity of NCD on the first performance was found. These findings suggest that treated NCD had no effect on AFC and first lactation production. This would ensure suitable reproduction and production standards during the first lactation even in calves that have had severe NCD.