Replacing dairy cows is in seven out of ten cases not voluntarily: the main causes of premature culling are mastitis, claw and leg problems, and fertility issues. At an average age 26 months, a heifer gives birth to her first calf and has her first lactation start. The calving in itself is a radical event for the animal, coinciding with increased risks of various health issues, e.g., calcium deficiency, shortage of energy, and claw problems. This applies not only to heifers, but mainly to older cows. Especially the dry period is crucial to prepare for a good and flawless lactation start.
The transition period, three weeks before up to three weeks after calving, is a phase where many problems occur, because at time many processes in the animals are changing. A lack of calcium and/or energy can lead to many problems in dairy cattle. Examples comprise milk fever, ketosis, displaced abomasum, udder infections, fertility problems, et cetera. The figure below gives an overview of the main processes and domino effects occurring in the transition period.
Risks / domino effects around calving (transition period) (▲= increasing effect ▼= decreasing effect)
Transition diseases around the start of lactation are closely interrelated. Problems often start with a low calcium level in the blood. A lack of calcium often catalyses other health issues after calving.
On a dairy farm, 20 to 60% of all dairy cows suffers from a form of Ca deficiency around calving. Scientific research reveals that one case of milk fever costs approximately € 300. This includes costs of treatment and loss of milk yield.
A low calcium supply hampers muscle function, and this has consequences for all processes where muscle control is involved, like rumen contractions, uterus contraction at calving, but also the closure of the teat tip. Figure 1 clearly shows the consequences of all this. It is important to restore adequate energy and calcium levels of the dairy cow as soon as possible!
Already before calving, the cow starts to produce milk, thereby increasing the calcium requirement. The feed intake – and also the calcium intake – lags behind in this stage, and the uptake of Ca from blood and bones is often also limited. This may lead to a calcium deficiency, resulting in milk fever. Also, subclinical milk fever may occur: the cow is standing, but feed intake, rumen function, and immunity are compromised. Cows suffering from a calcium deficiency are more susceptible to metabolic and infectious diseases, e.g., mastitis. This is related to the impaired muscle function, leading to slower closing of the teat tip after milking.
It is of utmost importance that a dairy cow after calving starts feed intake as soon as possible. A good cow drink, like Topro Recover, containing energy, calcium, magnesium, vitamins, trace elements, and antioxidants, offers excellent support.
The number of cows with a lack of phosphorous seems to increase over the years. Phosphorous, like calcium, is mainly stored in the skeleton. Around calving, the cow loses P for the growth of the foetus and through the excretion of milk. The lower feed intake around calving leads to a decrease in P supply, easily resulting in a shortage of P. Phosphorous has various functions in the body. Muscle contraction is the main function in fresh cows. A lack of P weakens the muscles and makes it harder for cows to stand up after calving.
Also, the functioning of the rumen is compromised in case of P shortages. In practice, a lack of P almost always coincides with a lack of Ca. Unfortunately, P levels (in contrast to Ca levels) do not respond well to treatment. P deficient cows (‘downer cows’) are more difficult to recognize than Ca deficient cows.
Injectable P will result in a fast increase in P levels in the blood, but this P disappears quickly and is hardly taken up by the cells. A better method is to apply phosphorous orally. A Topro Phosphorus bolus is a easily soluble P and Ca supplement, that can be given shortly before and shortly after calving. Supporting the cow with a comfortable place to lie down, when needed combined with pain relief, is essential to stimulate the cow to stand up as soon as possible.
Preventing the occurrence of milk fever is crucial.
Cow with milk fever
It all starts with providing dry cows with a balanced and palatable ration, that is offered frequently and freshly. The diet should contain an adequate supply of magnesium. Animals with increased risk of milk fever may be supported with boluses and cow drinks around calving, to prevent problems.
The treatment of milk fever is aimed at supplying the animal as soon as possible with adequate amounts of calcium. Adding phosphorous is often needed too, because Ca and P are stored in the body together, in a Ca-P-complex form. Also magnesium plays a role, because Mg is also important for muscle function. In cases of acute milk fever, an intravenous supply of Ca and Mg quickly restores blood concentrations. There are other methods available, like drenches, boluses and powders. When a cow remains lying down with milk fever, it is important to assist her in standing up regularly, to stimulate blood flow in the body.
Cows with an increased risk of milk fever require a specific treatment, to enable them to proceed to the next lactation. Make a protocol for high risk cows around calving. Ask your veterinarian to assist you in drawing up protocols.
Protocol for High Risk Cows (example): Older dairy cows have an increased risk of milk fever. Some dairy farms supply all of their dry cows after the second lactation (at drying off) with a dry cow bolus, and give them calcium boluses (two before calving and two after calving). This measure can help to prevent problems.