The detrimental effects that mastitis can have on fertility is one of the largest indirect costs of the disease. Mastitis (both clinical and subclinical) have been showed to affect conception rates, compromise embryo development and calf health as well as increasing the risk of calving complications. Poor fertility results in costs associated with veterinary services, culling and low production. When evaluating what mastitis is costing your parlor, the effects on fertility cannot be ignored.
The metabolic stress associated with mastitis causes cows to be anovular (not cyclic) for prolonged periods of time. Follicular growth is inhibited, preventing ovulation and the inflammation caused by mastitis produces hormones called prostaglandins that are involved with regulating the oestrus cycle. Hormone levels too high or too low at the wrong point in the cycle will prevent regular oestrus and ovulation. While a period of approximately 40 days after calving is normal and needed for the reproductive system to heal, extended periods begin incurring costs.
The disruption of cyclicity results in increased calving to conception intervals and an increased number of …show more content…
As well as the cost of feeding open cows already discussed, cows with poor fertility have lower milk yields and generate less income from calf sales. Veterinary service costs are increased through the higher number of services required to achieve pregnancy as well as the potential calving complications and secondary health problems that mastitis can induce. Many producers choose to cull cows that show consistently poor fertility but this too can have hidden costs. If large numbers of the herd are being culled for fertility issues there are potentially cows with lower yields and higher Somatic Cell Counts that are staying in the herd, as well as an increase in the number of heifers reared as