Since 2002, when Dr. David Barker and colleagues proposed the hypothesis of maternal nutrition impacting post-natal characteristics, animal scientists have started to take a closer look into this area. They suggested that if uterine conditions during pregnancy are not favorable to embryo growth, the embryo would adapt and would be better prepared in the future if exposed to similar conditions.
Many terms have been used in the literature to explain this phenomenon (for example, neonatal programming, metabolic programming or metabolic imprinting).
Recently, the interaction between the environment and maternal nutrition has opened a new frontier in Barker’s hypothesis, and it has been driving the research focus in multiple universities.
In cow-calf operations, animals receive most of their nutrients through grazing. Often, forage quality is poor, particularly in the dry season, and may be inadequate to ensure optimal growth, pregnancy and lactation.
Nutrient supplementation would be recommended during this period. Supplementation is quite often forgotten during early to mid-gestation because of the lower nutrient requirements when compared to those at later stage of pregnancy and at early to mid-lactation.
The limitation of nutrients from the beginning until the middle of gestation reduces fetal weight in comparison to cows receiving adequate feeding, and adequate feeding at early pregnancy has effects on muscle growth and muscle fiber development of the fetus.
A study conducted at the University of Wyoming observed that protein supplementation of beef cows on 60 days to 180 days of gestation, increased muscle growth and lean meat and fat ratio in calves.
The maternal nutrition during the last third of gestation improves immunological function of the calf, helping to withstand low temperatures during newborn and increase survivability of newly born calves by 20 percent when compared with herds of cows that did not have their nutritional demands met during this same period.
When energy, protein, vitamins and minerals are not supplied in sufficient quantities to cows during the last third of gestation, it can cause a decrease in the concentration of immunoglobulin important for defending the body against pathogens.
The most consistent progeny result when supplementing dams during the middle and end of pregnancy is the increase in weaning weight by 4 to 7 percent.
Other responses to supplementation are still being evaluated. About 50 percent of the studies to date indicate that maternal supplementation during middle to late gestation increases hot carcass weight, marbling and proportion carcasses grading choice.
This suggested that the impact of maternal nutrition on progeny performance is still under investigation, and studies with larger number of animal will be needed to better understand this.
This is a fascinating area of research, which will get more complex when combined with “omics” and microbiome knowledge.
As of right now, we can conclude that inappropriate maternal nutrition during gestation can cause different impacts on the progeny, such as increase in neonatal mortality, alteration in muscle and fat growth patterns, meat quality, milk production and potential susceptibility to metabolic disorders. 
Ana Verdugo works with Cargill Animal Nutrition in ruminant nutrition.
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Research and Development Manager - Ruminants
Cargill Animal Nutrition
