Transitioning pregnant cows off winter crops
For successful transitioning off winter crops, planning starts early. Benefits include maintaining good rumen function and balancing the diet for cows in late pregnancy.
This allows the cow to adapt gradually to the change in diet before calving, minimising animal health issues, such as poor rumen function, ketosis, and fatty liver. These problems can lead to an increased risk of metabolic disorders such as milk fever at calving time and impact peak milk production.
The type of crop influences the transition plan. The more radical the change in diet, the longer it takes. For winter brassicas such as kale, the transition onto a pasture-based diet is quicker compared to coming off crops such as fodder beet. This is due to the rumen having to make bigger changes in its bug population and how it digests food.
An element of successful transitioning off-crop is budgeting for the extra supplementary feed, such as baleage or hay, and the pasture that will be required. If moving stock on and off the crop during the transitioning period, planning to finish the crop beside a pasture paddock can make this easier and more achievable.
In late pregnancy, animal requirements for protein increase due to the growth of the calf’s skeleton and muscles. Protein is also important for the development of the udder mammary tissue of the dam and colostrum production. These factors can influence the best time to transition off crops. Fodder beet is a high-energy, high sugar and low-protein feed. A protein deficiency is a risk on fodder beet crops and can impact calf birthweight and stature. It is recommended to transition cows off fodder beet crops at least four weeks pre-calving.
Commonly, multiple cuts of silage or baleage are done during the season. Each cut has a different nutritional composition such as varying protein and fibre levels. Testing supplementary feed aids decision-making on when to feed the different cuts. For example, it would be best to feed the baleage that has a higher protein percentage when the cows’ requirements for protein are higher, such as in later pregnancy and during transition off crop.
For help feed testing, and for advice on crop management, contact your local PGG Wrightson Technical Field Representative.
