Recently, there have been several reports of cows eating stones, plastic and many other things they should not while grazing.
According to The Agriculture and Horticulture Development Board (AHDB), this abnormal behaviour is called pica.
While animals showing pica can look healthy, this behaviour can lead to undesirable consequences, such as ingesting an object that could damage the internal organs of the cow.
AHDB say that the reasons behind pica are not completely clear, but these abnormal activities are generally associated with mineral deficiencies, such as sodium or phosphorous. Pica can also be associated with a lack of structural fibre.
According to AHDB, a lack of structural fibre in grazing herds is unlikely at this time of the year as grass enters the reproductive phase. Therefore, mineral deficiencies is the most probable cause of pica in the herd.
They recommend that you talk to your vet about running blood tests to check the mineral status of the herd, however, diagnosis of mineral deficiencies through a blood test can be challenging.
Additionally, they say it could also be worth taking a grass sample for mineral analysis and discussing the total dietary mineral content with a nutritionist.
If the issue is confirmed as being a mineral deficiency, supplementation with blocks or licks might limit or eliminate the abnormal eating habits. In other cases, rebalancing the diet and/or providing a source of long fibre may improve the situation.