Effects of Developmental Programming Caused by Maternal Nutrient Intake on Postnatal Performance of Beef Heifers and Their Calves

Simple Summary The nutrient intake of a cow during the early stages of pregnancy can have detrimental effects on the developing fetus. The adaptive response of the fetus to the restricted intrauterine environment can modify organ development. In this study, we assessed the consequences of maternal undernutrition in the first third of gestation on female offspring during its rearing, gestation, and lactation periods. We confirmed that maternal nutrient restriction decreased the heifer live weight at weaning (four months old); this difference disappeared at puberty, the end of rearing, and during the following gestation and lactation periods. Consequently, heifers from nutrient-restricted dams had impaired metabolic status around the onset of puberty. Maternal undernutrition reduced the number of antral follicles at breeding (16 months old); however, it did not affect the pregnancy rate after a single artificial insemination nor the calf weight gains during the first lactation period. In conclusion, early maternal subnutrition had long-term effects on heifer postnatal performance during the first four months of life which compromised heifer metabolic status during rearing but did not affect the reproductive performance during its first gestation and lactation periods. Abstract In this study, we evaluated the effects of maternal subnutrition in early pregnancy on the growth and reproductive performance of female offspring during their rearing, first gestation, and lactation. We inseminated 21 Parda and 15 Pirenaica multiparous cows and assigned them to a CONTROL (100% of nutrition requirements) or SUBNUT (65%) diet until day 82 of gestation. Cows were fed 100% requirements afterward. During the rearing of female offspring, growth, physiological profiles and ovarian follicular dynamic were studied. At 16 months old, heifers were inseminated. After first calving, dam-calf weights were recorded during lactation. Heifers born from CONTROL cows were heavier at weaning (four months old) than heifers born from SUBNUT cows, but this difference disappeared at the end of rearing and during the first gestation and lactation periods. All heifers reached puberty at a similar age and live weight. During rearing, SUBNUT heifers had higher concentrations of non-esterified fatty acids, urea, and cholesterol and a lower antral follicle count than CONTROL, but no difference was found in their fertility rate. After heifer first calving, dam-calf weights were similar among groups. In conclusion, maternal undernutrition reduced offspring postnatal gains at weaning, compromising metabolic status and follicle population during rearing but did not impair performance in the first gestation and lactation periods of beef heifers.