During the transition period dairy cows are at higher risk of developing infectious and metabolic diseases that result from sudden changes in behavior and metabolism. Among these changes the reduction in intake in the weeks close to calving is likely to be the change with the most profound effect as predisposing cause for metabolic problems.
Relationship between dry matter intake, lameness, and the occurrence of metabolic diseases
Inadequate nutrient intake has been associated with common problems such as metritis, subclinical hypocalcemia and subclinical ketosis. To further complicate things a reduction in dry matter (DM) intake during the close-up period may prolong and aggravate the negative energy balance during the transition period through fat mobilization.
This increased metabolism in the adipose tissue and the liver causes a state of inflammation has been linked to higher occurrence of several of these per-parturient problems. Adequate nutrition is also fundamental to maintain hoof integrity and prolong productive life. Lameness continues to be the second highest reason of dairy cow culling in the U.S., right behind mastitis. Furthermore, lameness is considered among the best welfare indicators for dairy cattle.
Subclinical acidosis and its clinical manifestation, laminitis, may result from nutritional or even management errors. Inadequate amounts of dietary effective fiber can result from excessive grain supplementation, the presence of highly fermentable carbohydrates or changes in the fiber/carbohydrate ratios.
One other important aspect to assess the health status of dairy cows is body condition scoring. While subjective, it is still a very useful and practical visual assessment tool of the nutritional status of cattle with high percentages of repeatability attained with practice, both between measurements and scorers.