Environmental perturbations during gestation can alter fetal development and postnatal animal performance. In humans, intrauterine growth restriction (IUGR) resulting from adaptive fetal programming is known as a leading cause of perinatal morbidity and mortality and predisposes offspring to metabolic disease, however, the prevalence and impact in livestock is not characterized as well. Multiple animal models have been developed as a proxy to determine mechanistic changes that underlie the postnatal phenotype resulting from these programming events in humans but have not been utilized as robustly in livestock. While the overall consequences are similar between models, the severity of the conditions appear to be dependent on type, timing, and duration of insult, indicating that some environmental insults are of more relevance to livestock production than others. Thus far, maternofetal stress during gestation has been shown to cause increased death loss, low birth weight, inefficient growth, and aberrant metabolism. A breadth of this data comes from the fetal ruminant collected near term or shortly thereafter, with fewer studies following these animals past weaning. Consequently, even less is known about how adaptive fetal programming impacts subsequent progeny. In this review, we summarize the current knowledge of the postnatal phenotype of livestock resulting from different models of fetal programming, with a focus on growth, metabolism, and reproductive efficiency. We further describe what is currently known about generational impacts of fetal programming in production systems, along with gaps and future directions to consider.

The COVID-19 pandemic has greatly affected higher education, but when learning shifted to an online environment it provided an opportunity to gain insight into how classroom format influences student performance and preferences. Thus, our objective was to assess student performance across classroom types, along with student perceptions of learning, to better understand the learning environment at the height of COVID-19. We evaluated student performance by final grade in undergraduate animal genetics (ANEQ 328) and large animal physiology (ANEQ 305) courses across four semesters, from before the pandemic through the return to in-person learning. In addition, students received surveys with questions regarding their learning experience. Survey analysis showed a consistent influence of COVID-19 within the classroom, mostly due to secondary effects. Student performance increased (P < 0.05) or was maintained in the pandemic centered semesters compared to pre-pandemic scores. When in-person learning resumed, scores in the ANEQ 305 course were worse (P < 0.05) than any previous semester but scores in the ANEQ 328 course returned to pre-pandemic levels. Overall, this study indicated that student performance was not negatively affected by the online transition during COVID-19 in these two courses, but it did decrease student satisfaction with their learning.

Inadequate nutrition during gestation has been shown to impair growth and metabolism of affected offspring and can predispose them to lifelong inefficiency and poor performance. Development throughout preweaning has been studied and compared to carcass performance; however, the impact of nutrient challenge during gestation on post weaning growth, efficiency, and nutrition utilization is not well known. Thus, our objective was to investigate the impacts of maternal nutrient restriction in late gestation on wether lambs' lifelong performance, from birth through harvest. We hypothesized that lambs from nutrient restricted dams would have reduced growth efficiency, taking longer to reach market weight and yielding altered body and carcass composition. Twenty-two bred yearling ewes were fed a diet meeting 100% of National Research Council (NRC) requirements until the 110th day of gestion (dGA). From 110 dGA until lambing occurred, ewes were either maintained on a diet meeting 100% of NRC requirements (n = 10) or reduced to a diet of 65% of NRC requirements (n = 12). Beginning at birth, body weight and morphometrics were collected weekly for control (CONT; n = 4) and treatment (NR; n = 5) wether lambs. At approximately 71 days of age, wethers were weaned and placed into individual pens to simulate a controlled feedlot setting. Wether lambs were fed a commercial lamb finishing diet ad libitum and orts were collected to evaluate feed efficiency and growth. At 115 days of age, wethers were placed in metabolism crates for 5 days to allow for total collection or urine and feces in order to evaluate nutrient balance. Birthweight, weaning weight, and morphometrics did not differ between NR and CONT lambs from birth until weaning. However, there was a tendency (P &lt; 0.10) for a slower rate of gain from birth until weaning in NR lambs compared to their CONT counterparts. Current research in feedlot performance and digestibility is ongoing; however, thus far there are no differences in feed intake or average daily gain. These data suggest that a moderate nutrient challenge in the last month of gestation is not substantial enough to induce adaptive changes that result in differences in postnatal growth and performance.

Eighty-three American Wagyu steers (725 ±10.7 kg) were used to evaluate the effects of olive byproduct supplementation on feedlot performance and carcass characteristics. We hypothesized that with supplementation of olive byproduct would improve feedlot performance and longissimus muscle intramuscular fat composition. Steers were blocked by initial body weight (BW) and randomly assigned within block to one of two treatments. Treatments consisted of: 1) Control diet (basal ration with no olive byproduct) + 1 kg of supplemental cracked corn per animal per day, or 2) Control diet + 1 kg of supplemental olive byproduct per animal per day. Steers were housed in feedlot pens (n=4 steers/pen; 11 replicates/treatment) and fed a traditional American Wagyu finishing diet (DM basis: 68.4% DM, 14.3% CP; 74.8% TDN, 1.16 Mcal/kg NEg, 5.3% crude fat). Diets were delivered to pens, once daily, in the morning in amounts to allow ad libitum access to feed over a 24 h period. Olive byproduct and cracked corn were top-dressed to the appropriate treatment pens immediately after delivery of the basal ration. Steers were individually weighed on d -1 and 0, and approximately every 28 d throughout the 177 d experiment. Equal numbers of steers per treatment were slaughtered throughout the experiment and carcass data were collected. Data were analyzed using a mixed effects model of SAS (SAS Inst. Inc.) for a randomized complete block design. Steers receiving olive byproduct had a lower final BW (P &lt; 0.01) when compared to steers receiving the control diet. Longissimus muscle long chain fatty acids C18:1 and C:22:0 were greater (P &lt; 0.05) and C18:0 lesser (P &lt; 0.05) in controls when compared to steers supplemented with olive byproduct. Under the conditions of this experiment, feeding olive byproduct reduced final BW and had minimal impacts on longissimus muscle fatty acid composition.