Calcium Action

Milk Fever

• During lactation, there is a significant increase in the demand for calcium in dairy cows, which stresses the calcium balance. Any disruption to this balance can result in milk fever, reduced milk production and other health disorders.
• While most cows experience subclinical Hypocalcaemia after calving, some cows are at greater risk of developing clinical milk fever, a severe condition. Clinical milk fever can be life-threatening if left untreated.

Effects of Milk Fever

The main effects of Hypocalcaemia are divided into two categories:

• Milk Fever is the primary postpartum metabolic disorder and can result in Downer cow syndrome, death, and other severe consequences.
• Effects on Smooth Muscle: Calcium is essential for muscle contraction, and a lack of calcium can lead to mastitis, retained placenta, metritis, delay to first heat, infertility, ketosis, and abomasal displacement. These conditions can be severe and significantly impact the productivity and profitability of dairy farms.

Effects on the gut:

• Calcium is crucial in maintaining normal smooth muscle tone in the gut and rumen. Therefore, cows with extended periods of Hypocalcaemia may have poorly functioning rumens, leading to other metabolic problems, such as ketosis, displaced abomasums, laminitis, retained placentas, metritis, and mastitis.

Mastitis

• Cows with Hypocalcaemia are up to eight times more susceptible to developing subsequent mastitis. Calcium is essential in maintaining the normal muscle tone of the teat sphincter and postpartum uterus. Low calcium levels relax the muscle fibres, leading to the opening of the teat sphincter, allowing infection to enter and the development of mastitis. Hypocalcaemia can also impede the mammary gland’s inflammatory and immune defensive functions.

Reproduction

• Hypocalcaemia can relax the uterine muscle (myometrium) and prevent the regular uterine contractions required to expel the placenta and foetal membranes after birth. Freshly calved cows with Hypocalcaemia commonly experience retained placenta and metritis, leading to severe infection and delayed return to the first heat. Low calcium is associated with infertility, delayed return to heat, foetal membranes, metritis, and mastitis due to the absence of muscle tone and contractions, in which calcium plays a pivotal role.