Restricted- and over-feeding during gestation decreases growth of offspring throughout maturity

Abstract

To determine the effects of poor maternal nutrition on the growth and metabolism of offspring into maturity, multiparous Dorset ewes pregnant with twins (n = 46) were fed to either 100% (control; n = 13), 60% (restricted; n = 17), or 140% (over; n = 16) of National Research Council requirements from d 30 ± 0.02 of gestation until parturition. Offspring of these ewes are referred to as CON (n=10 ewes; 12 rams), RES (n=13 ewes; 21 rams), or OVER (n =16 ewes; 13 rams), respectively. Lamb body weights (BW) and blood samples were collected weekly from birth (d 0) to d 28 and then every 14 d until d 252. Intravenous glucose tolerance test (infusion of 0.25 g dextrose/kg BW) was performed at d 133 ± 0.25. At d 167 ± 1.42, individual daily intake was recorded over a 77 d feeding period to determine residual feed intake (RFI). Rams were euthanized at d 282 ± 1.82 and body morphometrics, loin eye area (LEA), back fat thickness, and organ weights were collected. The right leg was collected from rams at necropsy and dual-energy x-ray absorptiometry was used to determine bone mineral density (BMD) and length. Averaged from d 0 until d 252, RES and OVER offspring weighed 10.8% and 6.8% less than CON offspring, respectively (P ≤ 0.02). When adjusted for BW, liver and testes weights tended to be increased and decreased, respectively, in RES rams compared with CON rams (P ≤ 0.08). Additionally, RES BMD and bone length were less than CON rams (P ≤ 0.06). Treatment did not influence muscle mass, LEA, or adipose deposition (P ≥ 0.41). Rams (-0.17) were more feed efficient than ewes (0.23; P < 0.01); however, no effect of maternal diet was observed (P ≥ 0.57). At 2 min post glucose infusion, glucose concentrations in OVER offspring were greater than CON and RES offspring (P = 0.04). Concentrations of insulin in CON rams tended to be greater than OVER and RES ewes at 5 min (P ≤ 0.07). No differences were detected in insulin:glucose or area under the curve (AUC) for glucose or insulin (P ≤ 0.29). Maternal diet did not impact offspring triglycerides or cholesterol (P ≤ 0.35). Pre-weaning leptin tended to be 70% greater in OVER offspring than CON (P ≤ 0.07). These data indicate that poor maternal nutrition impairs offspring growth throughout maturity but does not affect RFI. Changes in metabolic factors and glucose tolerance are minimal, highlighting the need to investigate other mechanisms that may contribute to negative impacts of poor maternal diet.

Effects of poor maternal diet during gestation are detected in F2 offspring

“…A detailed description of the experimental design, animals, and diets used was previously reported ( Tillquist et al, 2023 ). To evaluate the multigenerational effects of poor maternal diet, first-generation (F1) ewes were used to generate an F2 population of offspring.…”

“…F1 ewes were maintained on a 16% sheep grain ( Table 1 ; Pleasant View Farms Inc., Somers, CT) and ad libitum second-cutting hay ( Table 1 ). The F1 ewes ( n = 37; Figure 1 (CON-F1, n = 10; RES-F1, n = 12; OVER-F1, n = 15]) were estrus synchronized between 16 and 19 mo of age using controlled intravaginal drug release devices (CIDRs; Zoetis, Parsippany-Troy Hills, NJ) and prostaglandin (Lutalyse, Zoetis, Parsippany-Troy Hills, NJ) and bred by live cover with one of two genetically related Dorset rams as previously described ( Reed et al, 2014 ; Hoffman et al, 2016a ; Pillai et al, 2017 ; Tillquist et al, 2023 ). Breeding rams were not genetically related to the breeding rams used to generate the F1 offspring.…”

“…F1 ewes were fed a control diet and between 16 and 19 mo of age were bred with 1 of the 2 genetically similar Dorset rams to generate the F2 population. F2 offspring were weaned at day 60 and underwent intravenous glucose tolerance tests and residual feed intake trials at days 133 and 167 of age, respectively ( Tillquist et al, 2023 ). F2 ram offspring were necropsied at day 285 of age and F2 ewes were maintained on a control diet for future breeding.…”

“…After birth, F2 lambs were maintained with their F1 dam and allowed ad libitum access to creep feed ( Table 1 ; Home Fresh 18 Sheep Starter, Blue Seal, Litchfield, CT) and second cutting hay until weaning at 60 d of age. F2 offspring ( n = 60; Figure 1 ) are referred to as CON-F2 ( n = 12 ewes; 6 rams), RES-F2 ( n = 7 ewes; 13 rams), or OVER-F2 ( n = 13 ewes; 9 rams), corresponding to the diets of the granddam (F0; Tillquist et al, 2023 ). Two F2 offspring died at birth for reasons unrelated to the experiment (CON-F2, n = 1; OVER-F2, n = 1; not included in statistical analysis).…”

“…Following the same collection timeline used for the F1 offspring ( Tillquist et al, 2023 ), F2 lamb BW and jugular blood samples (10 to 20 mL) were collected weekly for the first 4 wk and then every 14 d until 252 d of age. Crown-rump length (CRL), heart girth (HG), and hip height (HH) measurements were taken at days 0 and 120 of age.…”