The long-term impact of dystocia – it’s more than a calving pen problem.
Dystocia or difficulty during has been correlated with weakness, morbidity and mortality in dairy calves, however new research suggests dystocia may have long-term term impacts on dairy heifers, farm efficiency and calf welfare.
A prolonged and difficult calving can cause acidosis and hypoxia in the calf due to lack of oxygen and abnormal changes in blood gases (Figure 1). Both of these changes have detrimental effects on IgG absorption and gut closure, both which can lead to long term health risks. It has previously been reported that dystocia is associated with lower neonatal serum protein.
Data from the 2007 USDA National Animal Health Monitoring Systems study further supports that dystocia increases the risk of failure of passive transfer in heifer calves when veterinary assistance was not available to correctly position the calf in the birth canal.
Supplementation of oxygen and assistance to suckle did not affect dystocia calves’ ability to obtain adequate passive transfer. The reduced IgG serum concentration in dystocia calves could be related to the increase in endogenous corticosteroid release, and their effect on closure of the intestinal wall. Another explanation for this is that calves that experience dystocia often lack vigor, and may lack the ability to suckle the bottle.
While many studies often report on the impact of dystocia during the first 24 to 48 hours of life, it is important to note the lifelong impact dystocia presents. Failure of passive transfer during the first 24 hours of life will lead to a weakened immune system for life, thus the animal is always more susceptible to disease risks. Heifer calves that experience moderate dystocia are at a greater risk to die before weaning and before first service as compared to heifer calves born without difficulty. Calves that experience dystocia may have reduced growth to weaning thus increasing the days to first service and increasing the days to entering the milking herd.
Heifer mortality after birth, regardless of its cause is a welfare concern and has a direct economic cost to the producer. To reduce dystocia farmers can use calving ease sires, limit the use of natural service sires, train employees to know when to assist in a calving(don’t assist to early or too late) and know when to call a veterinarian to assist in a calving. To help reduce failure of passive transfer among dystocia calves, managers should feed calves high quality colostrum or colostrum replacer within the first hour of life. Calves should be dried, removed from the calving pen and placed in a dry, clean and well ventilated calf area.