Cow nutrition remains one of the most important management concerns for producers heading into calving. In the final 90 to 75 days before calving, fetal growth accelerates dramatically; research shows that 55% to 70% of the calf’s birthweight is gained during this period. Because of this rapid fetal development, the cow’s nutrient requirements increase substantially. If the cow’s diet does not provide enough energy and protein, she begins to draw on her own body reserves. This leads to loss of body condition, weakened immune function, reduced milk production, lower-quality colostrum, poor calf health and decreased rebreeding rates during the upcoming breeding season.
To mitigate these challenges and protect the productivity of both the cow and her calf, producers should aim to meet or exceed the cow’s elevated nutrient requirements. For mature cows in late pregnancy, a ration containing at least 55% total digestible nutrients (TDN) and 8% crude protein (CP) is required to maintain body condition and support proper fetal growth. Using higher-quality roughages, such as good alfalfa or mixed hay, or adding protein and energy supplements helps ensure cows consistently receive the nutrients they need throughout this critical period.
Body condition scoring becomes especially important as calving season nears. Mature cows should ideally calve in a body condition score (BCS) of 5-6, while first-calf heifers should be closer to BCS 6-7 due to their continued growth demands. Cows scoring in this range will have a smooth, well-fleshed appearance with noticeable fat cover over the ribs, hips and tailhead, without prominent bone structure. If you evaluate your cows at least three months prior to calving and find that animals are scoring below a BCS 5, there is still time to modify their ration and help them gain enough condition to reach the desired BCS by calving.
Common methods of supplementation include feeding higher-quality hay, incorporating corn silage or using commercial protein and energy supplements. It is always good management practice to test your forages for TDN and CP and then make supplementation decisions based on the results rather than assumptions. Although these inputs may increase winter feeding costs, proper supplementation improves calving outcomes and strengthens overall herd health and productivity.
With careful planning, through body condition scoring, feed testing and targeted ration adjustments, you can set your herd up for a successful calving season. The final weeks of gestation can be challenging, especially during harsh winter weather, but proactive nutritional management pays long-term dividends in calf health, cow fertility and overall herd efficiency.
