Source: OMAFRA
The transition from a dry cow to a milking cow is a particularly stressful time for dairy animals. It is important that the nutritional management during this time continues to be as good or better than during lactation. A variety of primary and secondary metabolic problems are common during the transition phase, such as ketosis and milk fever.
Minerals and vitamins are essential nutrients. These components of the cow’s diet are not just necessary for meeting minimum requirements to avoid deficiencies. Good nutrition of minerals and vitamins allows for mammary gland development, growth of the developing calf, and supports immune function. It is hard to measure, on a cow to cow basis, the impact that additional stress around calving can have because of differences between animals. Nutritional programs that deliver the optimal amounts of minerals and vitamins can promote good health and productivity.
Minerals and vitamins are associated with a variety of metabolic conditions as shown in Table 1.
|
Condition |
Mineral(s) associated: |
|---|---|
|
Ketosis |
Co |
|
Milk Fever |
Ca, P, Mg, Na, K, Cl, S |
|
Retained Placenta |
Ca, Se |
|
Displaced abomasum (DA) |
Mg, Ca |
The following recommendations for macro-minerals and vitamins (see Table 2) incorporate the latest NRC (2001) values and current recommendations from dairy nutritionists. It is recommended that anionic products be used with the advice of a dairy nutritionist. The recommendations here are divided into the traditional far-off and close-up transition cows. The close-up transition time period is the 21 days before calving.
|
Mineral |
Far-off dry cow (% of DM) |
Transition cow |
Transition cow |
|---|---|---|---|
|
Ca |
0.6 |
0.7 |
1.4 |
|
P |
0.26 |
0.3 |
0.4 |
|
Mg |
0.16 |
0.2 |
0.4 |
|
Na |
0.1 |
0.1 |
<0.1 |
|
K |
0.65* |
0.65* |
<1.5 |
|
Cl |
0.2 |
0.2 |
0.8 |
|
S |
0.2 |
0.2 |
0.4 |
|
Vitamin |
IU/day |
IU/d |
IU/d |
|---|---|---|---|
|
A |
100,000 |
100,000 |
100,000 |
|
D |
30,000 |
30,000 |
30,000 |
|
E |
1200 |
2000 |
2000 |
|
Niacin |
6-12 grams |
6-12 grams |
6-12 grams |
*Potassium is often higher than 0.65% in many Ontario forages. Typically it should be maintained below 1.2-1.5% whenever possible.
Trace minerals contribute very small amounts to the overall diet. There are very few reported instances of deficiency in North America, however they also contribute to overall health and productivity. Recommendations for some trace minerals are shown in Table 3.
|
Trace Mineral |
Far-off dry cow (PPM) |
Transition cow (PPM) |
|---|---|---|
|
Co |
0.11 |
0.11 |
|
Se |
0.3 |
0.3 |
|
Zn |
60 |
60 |
|
Cu |
12 |
18 |
Mineral nutrition of dry and transition cows depends on accurate feed analysis to ensure that precise amounts are determined in feeds so that supplements can balance the diet. It is recommended that forages be tested using wet-chemistry rather than near-infrared (NIR) measures. See the OMAF nutrient testing information sheet for further information on feed analysis.
Mineral abbreviations: Ca (calcium), P (phosphorus), Mg (magnesium), Na (sodium), K (potassium), Cl (chloride), S (sulfur), Co (cobalt), Se (selenium), Zn (zinc), and Cu (copper).
