Minerals and the Transition Period
The Transition cow mob, more commonly referred to by farmers as the springer cow mob, has the potential to respond to a higher level of thought and attention. Making key decisions around feeding and supplementation of this mob can have a bigger impact on a dairy farm’s profitability than any other single set of management decisions made throughout the rest of the season. A well transitioned cow will normally produce more total milk, have less disease issues, and a better reproductive outcome, than cows that don’t receive as much attention around this time.
Most experts agree that the transition period begins 21 days prior to the day the cow gives birth, into 21 days of lactation. For any cow this is a period of vast metabolic change. During this time their hormone levels are going through rapid developments as the body gets ready to mobilise many of the key minerals required, as well as preparing her body to mobilise the vast amounts of energy required during birth and lactation. Transition is normally the single highest stress period a cow will experience each year.
A TIME NOT TO DO THINGS BY HALVES
Both the period prior to calving and the period after calving are equally important to ensure the cow will produce at her potential, remain healthy and conceive again when mated. In my experience farmers will tend to either concentrate on the period leading up to calving or the period after – most commonly the period after calving gets most attention. And this can create a problem. In this article we will concentrate on the transitioning of cows only, rather than heifers (first calvers) where the focus need only be on ramping up the feed rate prior to calving. Transitioning cows is a very different process, a cow that is not transitioned correctly leading up to calving is a cow that will calve with her metabolic processes operating well short of full potential. She will be more exposed to both clinical and subclinical metabolic disease through either being calcium deficient or lacking the ability to mobilise sufficient calcium, ketosis, fatty liver disease, or possibly a combination of these problems.
POWER UP YOUR COWS
When looking at the transition period prior to calving we need to be thinking about powering the cows metabolism up in anticipation of the stresses she will face at calving and in the weeks just after. This requires taking a close look at the diet planned for those final 3 weeks prior to the expected calving date. A good transition diet will insure that the transition cow receives at least minimum levels of calcium, phosphorous, and sodium, while magnesium and trace elements are also well maintained. The pre-calving diet should also be as low in potassium as possible. Be aware that our grass pastures are always very high in potassium, while often being low in magnesium, they will also most likely be low in at least some of the trace elements during this period of the season. Correct supplementation can be critically important at this time, especially if body storage levels of these required minerals are already low.
KNOW YOUR DCAD
Of even more importance over this period is the total Dietary Cation Anion Difference (DCAD) of the diet and its resulting effect on the pH of the blood, as this balance will affect the body’s ability to release and utilise minerals more than any other single aspect of nutrition.
The total DCAD (anion level) that can be achieved within the diet is largely controlled by the level of total potassium in the diet. This in turn is directly associated with the quantity of pasture being fed vs low DCAD feeds such as maize silage, low potassium crops, grain based feeds etc… Unfortunately feeding grass silage or pasture hay is of little benefit to the DCAD as these will also be high in potassium. Depending on the herd’s specific feed plan a good anionic salt blend (negative DCAD) should seek to achieve a slight level of metabolic acidosis to lower both blood and urine pH. When this slight change in blood acidification occurs trials have consistently shown that the body is then capable of mobilising higher levels of key hormones related to calcium and phosphorous absorption, most notably parathyroid hormone and vitamin D.
Anionic (negative DCAD) salts are relatively low cost and when blended correctly, are easily blended into silages, and can be formulated to be palatable even at high rates of inclusion. Provided the salts are correctly formulated, mineral intakes even in excess of 350 grams can be dosed without palatability issues. These levels of dosage can achieve an immediate and major drop in the total DCAD levels of the diet. When dosed correctly these salts are an effective way of mitigating the majority of issues likely to be faced during transition and the early lactation period of transition.
SECOND HALF, NEW GAME PLAN
As noted earlier, the period after calving is equally as important as the period before, and should also be considered as the second key phase of the transition period. If the body’s increased demand for calcium and phosphorous are not met after calving, these same cows will still have some risk of suffering either clinical, or more commonly subclinical, metabolic disease, setting them up for other calcium related deficiency problems further on in lactation. During this second period of transition, the approach to supplying these mineral salts changes, instead of (Anionic) negative DCAD forms, we instead switch the diet to the alkaline salts farmers are more familiar with, such as magnesium oxide and lime flour. These forms, as well as supplying calcium and magnesium, also help to buffer rumen acidity and drive appetite on the increased energy diets of early lactation.
The same factors apply to energy, a well transitioned cow will be more like a finely tuned racing car when compared to other cows, while she will be able to more efficiently use energy, she will also require good quality fuel and plenty of it. Fuel her up correctly and she will repay you with increased production and less health problems.
TRANSITIONING WELL DELIVERS RESULTS
The simple process of correctly transitioning a cow throughout this entire period will ensure good blood calcium levels are maintained and a high rate of calcium mobilisation can be achieved throughout lactation. Research has consistently shown that cows with high blood levels of calcium during early lactation also have a higher neutrophil function (increased immunity). Over the years there has been a large body of research linking blood calcium levels with metritis, RFM’s, displaced abomasum’s and poor reproductive performance, clearly showing the importance of achieving adequate blood calcium levels (>8,59 mg/dl) in dairy cows.
A good transition diet pre-calving needn’t cost much, on average pre calving $5.50 – $8.00 depending on the formulation. Post calving most farmers are spending a reasonable amount anyway, this expenditure simply needs applying in a more planned way for better results.
Agvance Nutrition in association with your vet have the software tools to accurately calculate the ideal transition diets. We can build blends for both the pre-calving and post-calving periods, we also offer free advice around correct feeding and management throughout this period.
For more information on transition mix’s containing anionic salts, calcium salts, phosphorus, monensin and trace minerals, talk to your vet or get in contact with the Agvance team.