26 NEBRASKA CATTLEMAN February 2026 pre-weaning was not as severely altered as expected considering milk nutrient and calf growth differences. At harvest, calves born to nutrient-restricted dams had lower dressing percentage, but improved yield grade and backfat thickness. Final feedlot body weight, hot carcass weight, ribeye area and quality grade were not affected by maternal treatment. Outcomes in the Second Pregnancy and Lactation Females were managed together and followed through weaning of their second calf to determine if there were carryover effects during the subsequent parity (Figure 3). Previously nutrient-restricted dams still weighed roughly 100 pounds less and were 0.6 lower in body condition score when measured at multiple points during late gestation and lactation. Uterine blood flow, placental size and calf birth weight were unaffected by nutrient restriction during the first pregnancy. Colostrum yield, nutrient composition and immunoglobulin G concentrations had recovered and were similar between treatments. Milk yield and nutrient composition also recovered; however, the reduction in milk protein concentration in previously nutrient-restricted dams still remained. Reduced LATE GESTATIONAL UNDERNUTRITION CONTINUED FROM PAGE 25 Figure 3. Effects of late gestational nutrient restriction in the first parity on dam and offspring outcomes in the second parity. mammary blood flow persisted in the second lactation and was 18 percent less for previously nutrient-restricted dams. During the second parity, differences in lactational performance were not severe enough to alter calf pre-weaning growth as weaning weight was similar between treatments. Implications Although late gestational nutrient restriction may not always reduce birth weight, our results illustrate that colostrum and milk production was impaired by nutrient restriction, resulting in decreased pre-weaning growth. Calves born to nutrient-restricted dams had lighter weaning weights, which would ultimately affect cow-calf profitability. While no calves died in the research setting, it is more likely that calf malpresentations at birth, reduced calf vigor and altered colostrum composition could lead to decreased calf survival in nutrient-restricted heifers in a production setting. Additionally, persisting effects in the second parity on maternal size, fleshing ability and mammary blood flow demonstrate the possibility of long-term programming effects on the dam, which could have implications for cow longevity in the herd. These results reinforce the importance of providing adequate nutrients to pregnant beef cattle, especially first-calf heifers that are still growing. This work was supported by USDA-AFRI grant 201767015-26587 and the Illinois Beef Association. Previously published in the March/April 2023 digital edition of BEEF magazine. ~NC~
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