Fetal Development: Realizing the WHAT to Accomplish the WHY

Chris Cassady, Ph.D., BioZyme® Inc., Beef Technical Sales Manager

When constructing a home or putting up a building, ideally, you’d engineer something that can last a lifetime. A well-assembled structure begins with setting a foundation crafted to be stable, durable, and supportive. Your cow-calf operation is no different, and the long-term successful outcomes of each calf start all the way back to when the bull bred the dam. The challenge for producers is that a calf’s foundation is built internally, without any visual of its vigor until far into its postnatal life. Understanding WHAT is going on can help producers understand WHY annual premium nutrition is always worth it.

Typically, we tend to focus on nutrition during the last 60 days of gestation, when two-thirds of the fetal growth occurs in utero. Obviously, this is important, as a 90-pound calf at birth is growing nearly a pound a day during the end of gestation, and it takes a high plane of nutrition to support this requirement. Try not to put the cart in front of the horse, because while this exponential growth is important for the calf, there are many vital systems established in early gestation, such as placental growth, organogenesis, and muscle fiber development. Just like a poorly built foundation, the “cracks” in these systems may not be able to support the calf down the road if nutrition is restricted.

Just like a building inspector, let’s look at the foundation or the developing systems that take place after fertilization. After conception, the developing embryo divides and multiplies and enters the uterus around day 4. The critical period of maternal pregnancy recognition occurs simultaneously with the formation of the placenta between days 15 and 18. The effective vascular exchange of oxygen and nutrients from the dam to the fetus obviously relies on proper placental development. A heartbeat can be recognized as early as day 22, and vital organs like the lungs, liver, pancreas, kidneys, and brain begin development as early as day 25. Think about what would happen if nutrition were restricted during these developmental milestones. Research findings have suggested that early-gestation nutrient restriction can alter pancreatic and lung function, exposing the calf to glucose intolerance and impaired lung function. This obviously would have an impact on growing cattle efficiency and susceptibility to Bovine respiratory disease (BRD).

Fast forward to midgestation, where historically we associate nutritional requirements to be lowest throughout the year. While this is true for the cow, the developing fetus has established vital organs and is now partitioning nutrients toward muscle fiber development. At the end of the beef production cycle, we get paid for pounds of marketable product, so maximizing muscle mass is imperative. Nutrient restriction affects myogenesis, so fewer muscle fibers will be generated if requirements aren’t met. Terminal traits like ribeye area are highly heritable genetic traits, and without the proper nutrition provided, cattle producers won’t get the most out of the genetics they feed out or retain. 

Without a visual, it’s hard to know exactly WHAT is going on in there during the critical stages of fetal development. But knowing the time points, and WHY nutrition matters well before that last trimester can give you and your calves the best chance possible to thrive in their respective system. Products like AO-Biotics® Amaferm® assist with nutrient utilization by improving the digestibility of critical nutrients like energy and protein. The extra nutrition unlocked and made available by Amaferm can be partitioned beyond maintenance for the cow and onto her developing fetus. Collectively, providing premium nutrition year-round will pay dividends to any operation by giving that calf a sturdy, well-engineered foundation for its productive lifespan.

Start with a solid foundation, and don’t skimp on nutrition just because your cows aren’t in their last trimester. Give them the nutrition their calves deserve early on, and you will see the returns once that growthy, efficient calf is weaned.

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