EXAMPLE DIETS
Listed below are some of the nutrient recommendations that have been determined under experimental and practical situations. It should be noted that the high forage rations as well as the high concentrate rations used in the examples below were precision-fed to produce a level of growth to meet ADG objectives. Precision feeding highly digestible, high concentrate diets is still under development for dairy heifers, and knowledge is still incomplete. But this information can serve as a starting point for those interested in precision feeding dairy heifers. The final determination for the success of a precision feeding program is the animal herself, and careful and frequent monitoring of heifer progress is the key to successful application of this nutritional approach.
A strategy for practical ration balancing is to formulate a least cost diet based on the feeds available, meeting the required specifications, and then feed an amount of dry matter to meet the nutrient requirements. That is, assuming energy is most limiting for growth, determine the ME required by a heifer for a specific rate of gain (from the NRC, for instance) and divide the requirement by the formulated ration energy density (Mcal/d รท Mcal/pound DMI).
CONCLUSIONS
In summary, studies have shown that feeding higher concentrate rations in a restricted manner to growing dairy heifers from 4 to 22 months of age leads to similar growth performance with respect to weight gains and structural growth. Research results suggest, provided the level of intake is restricted to allow for an optimal level of ADG, high concentrate, precision-fed rations can be fed to dairy heifers successfully. Precision feeding heifers has the potential to reduce feed costs, reduce nutrient excretion, and increase feed efficiency without compromising future lactation performance.
