Don�t Forget Those Dairy Heifers on Pasture!!!

Dr. Ronald L. Boman
USU Extension Dairy Specialist

I recently talked with a dairy producer who was looking to rent pasture for his heifers for the Summer. He wanted to get them out of the corrals and into a more healthy environment and at the same time reduce the labor and expense of feeding them in dry lot. I was able to recommend someone to him that would not only pasture his heifers, but would also manage them in an intensive rotational grazing system. Too often producers put their heifers out to pasture in the Spring and forget that the pasture isn�t always going to be as lush and productive as it is at the start of the grazing season. While it is true that pasture reduces labor and feed costs of growing dairy heifers, we should manage the pasture and the heifers so that they consistently gain from 1.75 to 2.0 lbs per day. Electric perimeter and portable cross fences along with drinking water delivered to each pasture lot using polypipe make it possible to achieve these consistent live weight gains.

At the USU Dairy Farm for the past five years we have achieved average daily gains of 1.75 to 2.0 lbs for heifers of 12 months and older while grazing perennial ryegrass and orchard grass pastures. But, we have employed the principles of �Management Intensive Grazing� which are elaborated below:

Intensive rotational grazing management involves not only the pasture itself, but also the intensive management of the dairy animals on those pastures. We do everything possible to maximize high quality pasture growth, such as:
  1. Selecting adapted varieties of grasses and legumes;
  2. Providing adequate and timely irrigation water;
  3. Providing optimum fertilizer nutrients spaced throughout the entire growing season;
  4. Implementing weed control practices;
  5. Maintaining the pastures in a vegetative stage of growth;
  6. Grazing the pasture sward quickly and then allowing for a three to four-week regrowth period before grazing again.
We also manage the dairy heifers to optimize live weight gains and at the same time maximize the conditions for optimum pasture performance, such as:
  1. Grazing pasture sward at heights of 7" to 9" when the nutrient content is optimum and the animals can ingest the forage rapidly;
  2. Dividing the pasture into many small paddocks so that each paddock can be grazed quickly (24 to 48 hours for dairy replacement heifers) and then getting the animals off the paddock to allow for a three to four-week rest period;
  3. Not overgrazing the paddocks, but leaving a 3 to 4-inch residue so that the grasses and legumes can start to regrow quickly;
  4. Providing drinking water in each individual paddock so the animals don�t have to travel long distances for water;
  5. Not grazing paddocks too soon after irrigation to reduce hoof trampling and �pugging� of the pastures;
  6. Managing animal numbers or mechanically harvesting excess Spring growth to control seed heads and still have sufficient available forage to achieve the desired animal performance.
For your information I have listed below some of the conditions at the USU Caine Dairy Pasture Unit: If you have questions or comments about grazing management for dairy heifers, I would be pleased to answer them or discuss your questions and concerns. You can contact me at (435) 797-2163 or at ronb@ext.usu.edu. ©