Early juvenile but not mid-to-late prenatal nutrition controls puberty in heifers but neither impact adult reproductive function

Abstract

Objectives were to test the hypothesis that pre and postnatal nutrition in the bovine female, independently or interactively, affect age at puberty and functional characteristics of the estrous cycle of sexually mature offspring. Brangus and Braford (n = 97) beef cows bearing a female fetus were fed to achieve body condition scores of 7.5–8 (H, obese), 5.5–6 (M, moderate) or 3–3.5 (L, thin) by the start of the third trimester and maintained until parturition. Heifer offspring were weaned and fed to gain weight at either a high (H; 1 kg/d) or low (L; 0.5 kg/d) rate between 4 and 8 months of age, then fed the same diet during a common feeding period until puberty which resulted in compensatory growth of heifers in the L group. Heifers (n = 95) from the H postnatal diet reached puberty two months earlier (12 ± 0.4 months; P = 0.0002) than those from the L postnatal diet (14 ± 0.4 months). Estrous cycles of a subgroup of postpubertal heifers (n = 53) were synchronized to evaluate antral follicle count (AFC), rate of growth and size of the pre-ovulatory follicle, size of corpus luteum and ovary, endometrial thickness, and plasma concentrations of progesterone and estradiol-17β (E2). Although there was a trend for postnatal H heifers to have greater AFC and plasma concentrations of E2 compared to L heifers, neither pre nor postnatal nutrition affected any other physiological or hormonal variables, including short-term fertility. Postnatal nutritional effects on pubertal age remained the dominant observed feature.

Interaction of pre- and postnatal nutrition on expression of leptin receptor variants and transporter molecules, leptin transport, and functional response to leptin in heifers

“…Our decision to utilize only HH, MH, and LL groups for Expt. 2 was based on our earlier reported findings [25], as well as results of several pending reports [Garza et al and West et al, unpublished]. Collectively, these studies demonstrated that, in spite of the wide contrasts in maternal and postnatal nutritional regimes created by the factorial design, only diet or diet combinations employing severe undernutrition had any measurable effects on the plethora of target variables examined.…”

“…Collectively, these findings have important implications for our understanding of the effects of maternal and postnatal juvenile nutrition in ruminants, indicating an inherent resilience of female offspring to gross nutritional perturbations during prenatal and juvenile postnatal development. Moreover, related studies in our laboratory [25] have shown that neither severe maternal undernutrition nor overnutrition enhance or negate the ability of heightened postnatal nutrition to positively enhance pubertal maturation. Similarly, no maternal or maternal × postnatal interactive effects were observed on a wide variety of other reproductive physiological variables in adult, sexually mature females subjected to the same nutritional treatments [25].…”

“…Moreover, related studies in our laboratory [25] have shown that neither severe maternal undernutrition nor overnutrition enhance or negate the ability of heightened postnatal nutrition to positively enhance pubertal maturation. Similarly, no maternal or maternal × postnatal interactive effects were observed on a wide variety of other reproductive physiological variables in adult, sexually mature females subjected to the same nutritional treatments [25].…”