It is easy to discount cow nutrition during early pregnancy since 75 percent of fetal growth occurs during the last two months of gestation. Often producers supplement heavily in preparation for breeding, but then they slack off and wait until the last half of pregnancy to focus on supplementation again. However, maternal nutrition during early pregnancy is much more important than one might think.
Fetal programming simply means that the blueprints for how an animal will perform for the rest of its life are set during fetal development. Fetal development is controlled by a complex combination of both maternal and fetal mechanisms. Intrauterine fetal growth restriction occurs when these mechanisms are disrupted. Disruptions can take the form of under- or over-feeding cows during critical periods. Fetal growth restrictions have long-term effects. Evidence is mounting that in utero stunting permanently affects growth, feed efficiency, meat quality, fertility and overall health for the rest of the animal’s life. For example, steers from cows nutritionally restricted during pregnancy were observed to have reduced body weight and carcass weight at 30 months of age, as compared to steers from cows fed adequately during pregnancy.
The first few months of gestation are critical for the development of the placenta. The placenta, of course, is the organ that surrounds and protects the developing fetus. It controls all nutrient uptake, gas exchange and waste elimination by the fetus. Crucial to the bovine placenta are the placentomes (where the maternal caruncle and placental cotyledon join). Placentomes facilitate all physiological exchanges between fetus and mother. During this critical early gestation period, the number and size of placentomes are increasing, as is their vascularity, which controls blood flow. Decreased blood flow between the uterus and placenta is a primary cause of intrauterine fetal growth restriction.
Maternal nutrition directly affects development of the placentomes. Studies have shown that maternal under-nutrition or over-nutrition during this critical stage of placental development results in decreased total placentome weight, even after cow nutritional status is improved later in the pregnancy. Additionally, other studies have shown that blood flow in both the placental and maternal components of the placentomes is compromised.
Pregnancy results in increased metabolic activity (both maternal and fetal), which increases the production of oxidants. Waste oxidants can cause cell damage if not neutralized by antioxidants. Just like in human nutrition, antioxidants are very important in livestock diets. For these reasons, deficiency in antioxidant minerals (for example, selenium, copper, manganese or zinc) reduces survivability of embryos and fetuses. Studies have shown that supplementation with biologically available forms of these trace minerals improves reproductive performance, particularly in cattle that have undergone stresses in early gestation.
Early gestation is also a critical period for fetal organ development. Trace mineral status of the dam is critical, because micronutrient nutrition is essential for cell growth. When cells divide, DNA is transcribed to RNA, which is then translated into the proteins that make up the structure of the cell, as well as the enzymes found inside. At every step of the metabolic process, trace minerals are needed as signals or catalysts. Because different organs develop at different times, deficiencies will manifest themselves differently depending on the time period when the deficiency occurs. A heartbeat is detectable as early as 21 days after ovulation. The limbs begin developing by day 25, followed by sequential development of internal organs. A calf’s sexual organs begin development within the first 45 to 60 days. This is particularly significant for a heifer calf, since she will be born with every oocyte she will ever have in her entire life. Deficiencies during organ development can have livelong results.
So, what does this all mean in a practical sense? In light of what is known about fetal programing, future strategies for optimal growth and health in cattle production will start with prenatal management. Essentially, it boils down to giving cows what they need when they need it throughout the entire pregnancy. It is clear that nutritionally restricting cows and heifers during early gestation will negatively affect fetal development. Conversely, the animals should not be overfed during this period either, as over-conditioning also stunts fetal growth. Trace mineral and vitamin nutrition during the entire pregnancy is critical. Managers should use tools such as body condition scoring and nutritional analysis of forages and commodities to balance diets and allow for precision supplementation during the various stages of pregnancy.
Blueprint® mineral supplements help combat deficiencies and natural antagonisms by delivering organic chelated Bioplex® metal proteinates and Sel-Plex® selenium yeast as the ONLY sources of trace minerals. These are delivered at a targeted rate that is LOWER than current industry standards due to increased efficiency. Lower trace mineral levels and the reduction of sulfates and oxides in the diet reduce unwanted biochemical reactions to further increase animal efficiency. Because Bioplex metal proteinates and Sel-Plex selenium yeast are better absorbed and stored in tissues, this helps cows build adequate body stores needed for calf development, lactation and rebreeding. There are multiple formulations available in the Blueprint line that are easily interchanged to provide consistent nutrition throughout the year as the nutritional needs of your cattle change.
In summary, maternal nutrition, including mineral nutrition, during early gestation is just as critical as during later gestation. Fetal programing shows that nutritional disruptions during pregnancy can have far-reaching implications later in the calf’s life, and even into adulthood. The take-home message is to use Blueprint mineral and vitamin supplementation throughout pregnancy to help optimize fetal development and allow calves to maximize their genetic potential.
Blueprint®, Bioplex® and Sel-plex® are registered trademarks of Alltech