Focus on Late-Gestation Nutrition for Calves That Thrive
This article was written by Christina Hayes, Ph.D., cattle nutritionist with Purina Animal Nutrition
Did you know 75% of fetal growth occurs in the third trimester?
That’s why nutritional demands on pregnant cows are the greatest in late gestation. Focusing on nutrition during this key time of calf development – and year-round – will support the performance of both the cow and the calf.
What’s happening in late gestation?
Fetal programming, or the study of how nutrition and environment in utero affect offspring, has been researched by many universities over the past few decades. These studies have found that fetal programming has lifetime implications on growth, health and reproductive success of progeny, and a critical influencer is maternal nutrition during gestation.
During the last three months of a cow’s pregnancy, there is a significant increase in nutritional needs for protein, energy, vitamins and minerals. It is important to meet these elevated requirements before calving to nourish the cow and prepare the calf for a healthy start.
As calving time approaches, the rapidly growing fetus goes through final lung development, critical to their preparation for breathing air. Late gestation also influences fetal muscle and adipose tissue formation. Once the calf is born, muscle fiber number is largely established for their lifetime. Nutritional deficiencies during late gestation can reduce muscle fiber number and adipocyte development, impacting calf growth performance, feedlot efficiency and corresponding carcass quality.
Seasonal nutrition differences
The timing of calving and region of the country will affect management and nutrition decisions in late gestation. Having good quality forage available is essential, but as seasons change, it can be challenging to meet nutritional requirements during this critical time of fetal development.
The lead-up nutrition for spring calving can have many variations depending on when calves hit the ground.
When calving happens early in the year, from January to February, additional protein and energy may be necessary due to cold temperatures to maintain cows before calving. In areas where dormant forages are the primary feedstuff, consider supplementation strategies designed to meet cow nutrition requirements and maintain body condition.
If calving later in the spring, forage is limited in growth and volume from March to May and may not be enough to support increasing cow nutrient requirements. Monitor forage availability and stocking rates to maintain forage quantity throughout this grazing period. Supplementing with stored forages until grass amounts are adequate will help maintain cows in a body condition score (BCS) 6 at calving.
Fall calving herd management differs depending on the environment. In colder areas, the stress of maintaining body heat may increase nutrient requirements to maintain body condition. Analyzing forage, whether grazed pasture or stored forages, will provide a baseline to evaluate nutrient and supplementation needs. Especially important for fall-calvers, maintaining body condition is critical to breeding back in winter temperatures, which can be the toughest time of the year.
Nutrition 365 days a year
BCS is a quick and easy way to evaluate how your nutrition program is working. Aim to keep your cows in BCS 6 year-round. Cows in BCS 6 heading into calving season have the nutrient reserves to support a healthy birth and optimal colostrum production, giving rise to a strong calf with good vigor. When cows stay in BCS 6, there is no need to play catchup with nutrition.
Should cows start to slip below BCS 6, it is time to review the feeding program and look at cattle supplements.
Additionally, when body condition drops during the grazing season, it is a lagging indicator of declining forage conditions.
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