Fetal Programming: The Outcome of Maternal Nutrition 2015 Florida Fall Cattlemen’s Conference Dr. Matt Hersom Associate Professor / Extension Beef Cattle Specialist UF/IFAS Dept. of Animal Sciences

What is Fetal Programming? The process through which a stimulus or insult establishes a permanent response in the offspring Developmental programming hypothesis Exposure during a critical period in fetal development may influence later metabolic or physiological functions in adult life There is an increasing amount of popular press and research efforts being expended on the concept of fetal or developmental programming. So just what is fetal programming and why as a Florida cow-calf rancher should I care. First, fetal programming is the process through which a stimulus-a positive effect, or insult-a negative effect produces a permanent response that is manifest in the offspring of the dam. The idea is that the exposure to the positive or negative effect has to occur at a critical period during the development of the offspring is going to influence a number of metabolic or physiologic functions that will dictate how whether the animal lives or dies, grows, performs, and at what level is does these functions.

More on Fetal Programming During development in the womb, there are critical periods of vulnerability to suboptimal conditions. Vulnerable periods occur at different times for different tissues. The placenta plays a key role in programming. Compensation carries a price. In an unfavorable environment, the developing fetus makes attempts to compensate for deficiencies. However, the compensatory effort often carries a price. These critical periods are thought to be specific to each species. The suboptimal conditions are mostly thought to be a function of low nutrient supply from the mother and supplied to the fetus. The particular vulnerable periods are specific for each tissue because different tissues initiate and develop at different times, rates, and in response to nutrient flow from the maternal side. Because most of the suboptimal conditions are a function of nutrient supply the placenta is paramount in outcomes of fetal programming. The scope of placental involvement includes # of cotyledons, vascularization, and nutrient transport across the placental components. Life is a resilient process, Every system attempts to regain homeostasis or equilibrium. To that end the fetus will attempt to compensate for limited nutrient supplies. The compensatory response is often exhibited after birth through decreased health status, increased organ mass, decreased muscle mass, decreased fat deposition, and suppressed physiological mechanisms.

What Drives the Outcome of Fetal Programming? Nutritional Influence Altered cell number or intracellular organization Metabolic Differentiation DNA Control? (altered cell specific gene regulation) DNA Environment? (altered DNA binding proteins) Altered DNA methylation? Reorganisation of organ structure Abnormal early cell-cell interactions? So what are the nuts and bolts of fetal programming, what is going on in the animal. First the animal is affected at the DNA level. The regulatory functions that control the cell and that a cell controls may be compromised. The DNA environment is altered in the replication process, the process that creates proteins which ultimately lead to the functions the cell carries out, stuff like making insulin in the pancreas, hormones in the pituitary, ovary, testis. Finally changing the structure of the DNA which will ultimately affect gene regulation and cell metabolism (the above 2 pts). As a result of different DNA function the cell number and functionality may altered (up or down, which are positive or negative depending on the cell type and tissue location). Organization of cells into tissues of similar type and function is important. Finally, once cells and tissues are affected the next step is that whole organs may have an altered/decreased function. In the end, the normal physiology and function of an organ is compromised and the animal is affected. Dysfunction of one organ can cascade into many other organ systems.

Maintenance Requirements Cow Nutrient Intake Maintenance Requirements Lactation Gestation Fetal Organs Fetal Skeletal Fetal Reproduction Fetal Muscle Fetal Adipose (Growth) Cow Nutrient Hierarchy of Use

Bovine Fetal Growth Time Line Think about how your production calendar fits this time line. What nutritional insults do your cows experience? This is a timeline of the early bovine fetal development. The timeline starts at the top with day zero being ovulation. As you look through the timeline think about the questions on the right. How does this timeline fit with your production calendar. What if any nutritional insults do your cows experience and for how long? – be honest What then are the developmental functions that may be compromised during the nutritional insult. What is the actual result of the nutritional insult, is it costing you money, can you do something about it? Think about this, peak nutritional requirements occur 30 to 60 days after calving. During this same time period, many of the differentiation of important organ systems: GI, Respiratory, Muscle, and Renal is occurring. Later other cellular differentiation occurs and growth of all tissues occur. Much of the fetal programming work has occurred in the 120 to 180 period, which is critical for the placental blood flow and nutrient transfer. But the foundation of the fetus and tissue/organ systems is laid down early on. What developmental functions are you compromising? What does it cost you?

Figure 1 depicts maternal nutrition effects on fetal skeletal muscle formation and control points in which maternal nutrition has been shown to impact fetal muscle development. Although primary muscle fibers of the bovine fetus form within the first 2 months of gestation (Russell and Oteruelo, 1981), very limited numbers of muscle fibers are formed at this stage; thus, maternal nutrition has little influence on primary muscle formation (Du et al., 2010). During the 2 to 7/8 months of gestation, the majority of muscle fibers form; thus, reducing muscle fiber formation During this stage through any source of stimuli (i.e. maternal nutrition) has long-lasting, irreversible consequences to the offspring (Du et al., 2010). Due to the importance fetal stage plays in adipocyte formation, Du et al. (2010) proposed the prospect of nutritional management altering marbling is greatest for the fetal stage, followed by the neonatal stage, early weaning stage (i.e., 150 to 250 d of age), and finally, weaning and older stages. http://cru.cahe.wsu.edu/cepublications/em060e/em060e.pdf

Du et al., 2013 J. Anim. Sci. 91:1419.

Du et al., 2013 J. Anim. Sci. 91:1419.

Nutrient Requirement Cycles and Pasture Characteristics January

Summary of strategic supplement needs - limitations Intake Energy Protein-RDP Phosphorus Sodium, Copper, Zinc, Selenium, Cobalt, Iodine J F M A M J J A S O N D

Fetal-Developmental Programming IMPORTANT TO ANIMAL HEALTH AND PRODUCTIVITY: Growth and nutrient transfer Reproductive capacity Aging and lifetime productivity As was previously mentioned, affecting cells, tissues, and organs can have systemic effects on the animal. From a beef cattle enterprise issue what does fetal programming affect. The effects could be simplistically broken down into 3 categories. Growth of the fetus and nutrient transfer across the placenta Reproductive capacity – this goes back to affecting cells and tissues. Aging and lifetime productivity – aging is the response to the ongoing stress of living and the ultimate productivity of the animal: lean tissue growth, lactation, fat deposition, etc

Post Natal Consequences for Depressed Maternal Nutrition Body Composition and Meat Quality Muscle and fat Cardiovascular disorders Growth performance Hormone imbalance Metabolic disorders Neonatal health Organ dysfunction & abnormal development Up to now we’ve talked about some of the physiology and mechanism of fetal programing. Here is a list of the outcomes of research that has investigated fetal programming through depressed maternal nutrition. These are outcomes that have been measured in livestock: sheep, swine, and some cattle. The lack of large scale cattle research is a direct reflection on the value and cost associated with doing this work in cattle compared to less expensive species like sheep and pigs. Regardless the consequences are reflected in changes in body composition and meat quality Heart development and circulation Growth performace Hormone imbalances – reproductive, metabolic and hormones related to growth Metabolic disorders – insulin resistance Neonatal health – survivability, early morbidity Organ function and development

Nutrients of Importance Energy Minerals Protein Vitamins Fats Which Ones What Concentration What Combinations So what are the nutrients of importance regarding fetal programming and potential nutrient restriction. The list should come as no surprise, these are the nutrient that are crucial for all beef cattle production, particularly when it is based on forage consumption. These nutrients are important for the physiological processes that the cow undertakes on an annual basis Energy – gestation, lactation, and reproduction are energetically costly. Protein – much of the research regarding beef cattle fetal programming has dealt with protein supplementation Minerals – minerals are involved with many of the metabolic functions that are involved in physiological processes Vitamins – see above Fats - have many specific functions and are components of many biological compounds and are key for membrane formation.

Protein supplementation During Late Pregnancy Impacts on female progeny reproductive success So now we’ll take the opportunity to examine some research results related to protein supplementation and the subsequent outcomes on heifer and steers. In general these research studies supplemented mature cows with a protein supplement while the cows were grazing native range in Nebraska. Dormant Native range pasture is generally always deficient in crude protein. The addition of a crude protein supplement provided rumen degradable protein to improve forage digestion, increase the energy supply in the diet, and also provide some bypass protein for the cow.

Effect of Maternal Protein Supplementation on Heifer Progeny Study 1 (42% CP) Study 2 (28% CP) No Supp Supp Weaning BW, lb 456 467 496 512 Adj 205-d wt, lb 481 498 470 478 DMI, lb/d 14.3 14.9 20.9 20.5 ADG, lb/d 0.90 0.88 1.87 1.74 RFI, kg -0.26 0.15 0.18 -0.09 Age at puberty, d 334 339 366 352 % Pregnant 80 93 90 On this slide are the results of two studies in which they compared the heifer offspring of either un supplemented cows or cows supplemented with a crude protein based supplement during the last third of gestation. Boxed items indicate signification differences between the two treatments. However in several cases you can see numerical differences between the treatments in one study and significant differences in the other study. In both studies weaning wt or 205-d weaning wt was increased for heifers from supplemented cows compared to unsupplemented cows. This should not be earth shattering result, but indicates that maternal nutrition during pregnancy can affect calf growth, because both treatment groups were handled similarly from calving until weaning. Post weaning dry matter intake, average daily gain, and residual feed intake were not affected by maternal treatment. As heifers were put through a similar developmental program one might expect similar performance in that regard. In fact if you look closely, while not significant the ADG of the unsupplemented heifers was slightly better than the supplemented calves. The unsupplemented calves are trying to catch up. Reproductive performance was affected by dam supplement treatment. Heifers from supplemented cows attained puberty at a younger age in study 2 and more heifers became pregnant in study 1 and numerically greater percentage in study 2. And ultimately more heifers from the supplemented cows became pregnant early in the breeding season and calved earlier. This is an indication of the improved reproductive maturity and fertility in the suppplemented heifers compared to unsupplemented heifers. While the reproductive data is not as robust as we might like, it still indicates that maternal nutrition, something as simple as providing enough protein in this case can have implications in the next generation thus affecting two calf crops. 28% increase in proportion of heifers calved in first 21 d of calving season from Supp heifers compared to No Supp Martin et al, 2007 and Funston et al, 2010

Effect of Maternal Feed Input and Heifer Feed Input on Performance Cow Marginal Supplementation (2.42 lb/d) Cow Adequate Supplementation (3.97 lb/d) Heifer Feed-Restricted Heifer Feed-Control BW at 5 yr, lb 1,136 1,169 1,080 1,113 BCS at 5 yr 4.9 5.1 4.7 5.0 Retention at 5 yr, % 48 46 39 49 Calf BW at birth, lb 74 77 Calf BW at wean, lb 432 443 445 450 The next evolution of work examined the effect of maternal nutrition on subsequent heifers and then layered on a nutritional profile on those heifers. So cows were either supplemented with a marginal amount of winter supplement (2.42 lbs/d) or adequate (3.97 lbs). Then the heifers were developed over 140 days using either a restricted amount of feed (80% of control) and 2.4 lb/d of supplement in the subsequent winters or ad libitum during development and 3.97 lb/d during subsequent winters. Looking now at the results, for BW of the heifers at 5 years of age, offspring from adequately feed cows had lower BW than marginal offspring and heifers developed in a restricted environment had lower BW compared to control. BCS at age 5 was lowest for Adequate-Restricted cows possibly indicating that an the adequate nutrition did not prepare the cow for the tougher nutritional environment she faced as a cow, whereas in contrast the Marginal-Control cows had the greatest BCS potentially indicating that the less than optimal nutrition in the maternal environment allows the cow to perform better when giving an “abundance” of nutrition as a maturing cow. Five-year retention when culled for reproductive failure was greatest for Adequate-Restricted cows and not different for the other treatments. This would seem to indicate that these cows were not metabolically-physiologically capable of performing in the nutritional environment that they were placed in, whereas the other treatments either had enough (M-C) or were fetally programed to deal with restricted nutrients (M-R) or utilized nutrients well (M-C). Calf birth wts were not different between treatments but generally lower for cows from a restricted dam in a restricted environment. Likewise, calf weaning wts, were lowest for cows from marginal dam who lived under restricted nutrition. This is a compounding function of lower birth wt and likely lower milk production potential and actual milk production prior to weaning. So a single season of maternal nutrition status can have long-term impacts on the performance of the offspring from those animals that experience the in utero nutritional insult. BW: effect of Dam nutrition treatment and Heifer nutrition treatment BCS: Adequate-Restricted lowest compared to others – why? Wean Wt: Marginal-Restricted lowest compared to others Roberts et al. 2009

Effect of Maternal Nutrition/Protein Supplementation on Steer Performance Study 1 Study 2 (28% CP) Native Range Improved Past No Supp Supp Weaning BW, lb 534 564 518 531 DMI, lb/d -- 19.7 20.3 ADG, lb/d 3.29 3.66 3.75 F:G 5.37 5.38 HCW, lb 728 767 803 820 Back Fat/Choice, % 0.49 0.64 71 86 Marbling Score 420 455 444 493 Now lets move to some steer data. On this slide are the results of 2 studies. Data in blue text indicate that the means are different between the two treatments. In study 1 dams grazed either native range or on improved pasture from day 120 to 180. After calving and weaning pairs and the steers were managed similarly. Steers from cows that grazed improved pasture for 60 days during gestation had greater weaning wt, ADG, hot carcass wt, and greater amount of backfat and tended to have greater marbling scores. In study 2 dams were either unsupplemented or supplemented 3 times per week with 1 lb of 28% CP supplement while grazing dormant range or corn crop residue during the last third of gestation. Steers from supplemented cows had greater weaning wt, dry matter intake, hot carcass wt, % choice, and marbling score. Other studies using this same cow herd have demonstrated consistent weaing wt results and hot carcass wt differences. Work in study 2 also indicated greater tenderness in steers from supplemented cows compared to unsupplemented treatment. Italics = differences between treatments Larson et al, 2009 and Underwood et al, 2010

Caton et al., 2007, FL Ruminant Nutr. Symp.

What Does Fetal Programming Do - Review Effects regardless of gender Weaning wt Post weaning ADG Age at puberty % pregnant Retention in herd Finishing carcass wt Fat/Marbling/% Choice Considering both the heifer and steer data together fetal programming through alterations in maternal nutrition and my convention the uterine-placental environment for the fetus results in a number of important consequences. The impact of the maternal nutritional environment has responses throughout the life of the animal.

Don’t Just Blame the Mom Research studies performed in rodents Drugs Carcinogens Environmental estrogens (BPA) Conclusions: Dad can impact fetal development Work in livestock is largely lacking Much if not all of the research as gone into looking at the maternal contribution to fetal programming. Research in rodents, where it is cheaper and easier to apply different insults, on the paternal contribution to fetal programming is being initiated. As you might expect, fetal programming effects can be transmitted through the sperm and into the offspring.

Future Directions for Research Time period of supplementation Specific nutrients that are important Maternal efficiencies Factors that impact uterine and placental blood flow What is the stuff that still needs to be figured out. What are the important time periods for supplementation, are there multiple time periods, which are the most important/priority. Which specific nutrients are important – we know that protein and energy supply are important, but what other nutrients have an effect, how much of those nutrients are effective Are there differences between cows, breeds, for maternal efficiency of nutrient use and how they react to nutritional insults or super-feeding of nutrients Ultimately blood flow to the uterus and placenta are important for delivery of nutrients to the fetus. Are there things that affect the blood flow that cattlemen can affect.

Treatment (T) and breed (B) Effect of Organic (ORG) and Inorganic (ING) trace mineral source in Angus and Brangus calves   Treatment (T) and breed (B) P-value Variable AN-ING BN-ING AN-ORG BN-ORG SEM Trt Brd T × B All calves 47 50 46 Weaning BW, lb 467 485 500 493 7.0 0.01 ADG, lb/d 1.92 1.98 2.07 2.00 0.04 0.81 0.12 Trt x Day = 0.03 * P < 0.05 *

Take Home Thoughts Fetal Programming – It’s a cow nutrition issue Cow nutrition is year-round issue How important is it that cows are nutritionally deficient It depends on what you do with the calves Do you care what kind of product you produce