Limiting maternal nutrient intake during ovine adolescent pregnancy progressively depleted maternal body reserves, impaired fetal nutrient supply, and slowed fetal soft tissue growth. The present study examined placental growth, angiogenic gene expression, and vascular development in this undernourished adolescent model at Days 90 and 130 of gestation. Singleton pregnancies were established, and ewes were offered an optimal control (C; n = 14) or low (L [0.7 x C]; n = 21) dietary intake. Seven ewes receiving L intakes were switched to C intakes on Day 90 of gestation (L-C). Fetal body weight (P < 0.01) and glucose concentrations (P < 0.03) were reduced in L versus C pregnancies by Day 130, whereas L-C group values were intermediate. Placental cellular proliferation, gross morphology, and mass were independent of maternal nutrition at both Day 90 and 130. In contrast, capillary area density in the maternal caruncular portion of the placentome was reduced by 20% (P < 0.001) at both stages of gestation in L compared with C groups. Caruncular capillary area density was equivalent in the L and L-C groups at Day 130. Placental mRNA expression of five key angiogenic ligands or receptors increased (P < 0.001) between Days 90 and 130 of gestation. VEGFA mRNA expression was higher (P < 0.04) in L compared with C and L-C pregnancies at Day 130, but otherwise gene expression of the remaining angiogenic factors and receptors analyzed was unaffected by maternal intake. Undernourishing the pregnant adolescent dam restricts fetal growth independently of changes in placental mass. Alterations in maternal placental vascular development may, however, play a role in mediating the previously reported reduction in maternal and hence fetal nutrient supply.
The objectives were to investigate effects of nutritional plane and Se supply during gestation on yield and nutrient composition of colostrum and milk in first parity ewes. Rambouillet ewe lambs (n = 84, age = 240 ± 17 d, BW = 52.1 ± 6.2 kg) were allocated to 6 treatments in a 2 × 3 factorial array. Factors included Se [adequate Se (ASe, 11.5 µg/kg of BW) or high Se (HSe, 77.0 µg/kg of BW)] initiated at breeding, and nutritional plane [60 (RES), 100 (CON), or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition. Colostrum was milked from all ewes at 3 h postpartum, and one-half of the ewes (n = 42) were transitioned to a common diet meeting lactation requirements and mechanically milked for 20 d. Colostrum yield was greater (P = 0.02) for HSe ewes than ASe, whereas CON had greater (P < 0.05) colostrum yield than RES and HIH. Colostrum Se (%) was greater (P < 0.01) for HSe than ASe. Colostrum from ewes fed HSe had less (P = 0.03) butterfat (%), but greater (P ≤ 0.05) total butterfat, solids-not-fat, lactose, protein, milk urea N, and Se than ASe. Colostrum from HIH ewes had greater (P ≤ 0.02) solids-not-fat (%) than RES, whereas RES had greater (P ≤ 0.04) butterfat (%) than CON and HIH. Colostrum from ewes fed the CON diet had greater (P = 0.01) total butterfat than HIH. Total solids-not-fat, lactose, and protein were greater (P < 0.05) in colostrum from CON than RES and HIH. Ewes fed HSe had greater (P < 0.01) milk yield (g/d and mL/d) than ASe, and CON and HIH had greater (P < 0.01) yield than RES. Milk protein (%) was greater (P ≤ 0.01) in RES compared with CON or HIH. Ewes fed HSe had greater (P < 0.01) milk Se (µg/g and mg/d) than ASe on each sampling day. Milk from CON and HIH ewes had greater (P < 0.01) total solids-not-fat, lactose, protein, and milk urea N than RES. Total Se was greater (P = 0.02) in milk from ewes fed the CON diet compared with RES. Somatic cell count and total somatic cells were greater (P ≤ 0.05) in milk from CON than RES. A cubic effect of day (P ≥ 0.01) was observed for milk yield (g and mL). Butterfat, solids-not-fat, lactose, milk urea N, and Se concentration responded quadratically (P ≤ 0.01) to day. Protein (%), total butterfat, and total Se, and somatic cells (cells/mL and cells/d) decreased linearly (P < 0.01) with day. Results indicate that gestational nutrition affects colostrum and milk yield and nutrient content, even when lactational nutrient requirements are met.
The present study aimed to examine the impact of maternal nutritional plane on umbilical hemodynamics. Ewes (n = 15) were assigned to 1 of 3 dietary treatments [control (CON; 100% of NRC requirements), restricted (RES; 60% of CON) or overfed (OVR; 140% of CON)] beginning on day 40 of gestation. Umbilical artery hemodynamics, fetal growth and placentome growth were measured on days 40, 45, 52, 80, 94 and 108 of gestation by Doppler ultrasonography. The percentage change in umbilical artery pulsatility and resistance indices remained steady through day 80 of gestation, and then decreased (P 0.05) on days 80 and 94 of gestation, and then decreased (P < 0.01) by day 108 of gestation. Maternal plane of nutrition can impact umbilical resistance indices, and ultimately may impact blood flow to the fetus.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Four ruminally and duodenally fistulated steers (469 ± 37 kg initial BW) were housed individually and arranged in a 4 × 4 Latin square to evaluate protein digestibility in steers fed a low to medium quality forage in response to protein supplementation. Steers were fed a chopped grass hay ad libitum (8.3% CP, 64.9% NDF) twice daily, plus (1) high-fat dried corn distillers grains (HDG, 10.8% fat, 0.8% of BW), (2) low-fat dried corn distillers grains (LDG, 5.7% fat, 0.7% of BW), (3) cotton seed meal (CSM, 3.0% fat, 0.4% of BW), or no supplement (CON). Supplements were formulated to provide isonitrogenous intake and to increase post-ruminal ARG supply. Each 21-d experimental period had 16 d of adaptation and a 5-d collection period. From d 12 to 20, 8 g of chromic oxide was dosed ruminally twice daily at h 0 and h 12 via gelatin capsule for use as a digesta flow marker. Grab duodenal and fecal samples were collected over 3 d in a manner that allowed for digesta to be sampled every other h in a 24-h period. Protein supplementation resulted in greater (P ≤ 0.0027) total OM and CP intake compared to CON. Intake of NDF was not different (P = 0.43) among treatments, whereas ADF intake was greater (P ≤ 0.0001) for CSM vs. CON, LDG, and HDG. Fat intake was greatest (P = 0.001) for HDG and lowest for CON, and CSM and LDG were intermediate. Greater (P ≤ 0.014) OM and CP duodenal flow rate was observed with protein supplementation vs. CON whereas differences were not (P ≥ 0.14) observed for NDF and ADF. Duodenal flow rate was greater (P = 0.005) for TAA with protein supplemention vs. CON, and ARG duodenal flow rate was greatest (P = 0.008) with CSM, lowest for CON, and intermediate for HDG and LDG. Apparent total tract digestibility for OM and EE was greater (P ≤ 0.03) with HDG, LDG, and CSM compared to CON, and NDF and ADF apparent total tract digestibility tended (P ≤ 0.07) to be greater with protein supplements than CON. Apparent total tract digestibility of CP, TAA, and ARG was lower (P ≤ 0.02) in CON than in protein-supplemented treatments. Post-ruminal supply of TAA and ARG was greater with vs. without protein supplementation. Overall fiber and protein digestibility improved with protein supplementation in low to medium quality forage diets.
A 2-yr study was conducted to investigate the effects of protein supplementation in low to medium quality forage diets on reproductive parameters during early pregnancy (-7 d to 30 d from TAI; d 0) in yearling beef heifers. Angus, Hereford, and Angus-cross yearling beef heifers (402 ± 42 kg initial BW; n = 79) were stratified by initial BW and BCS and randomly assigned to 1 of 4 supplemental treatments. Supplements were formulated to provide similar CP intake; 1) low-fat dried corn distillers grain (LDG, 7.4% fat; 0.8% BW); 2) high-fat dried corn distillers grains (HDG, 9.5% fat; 0.8% BW); 3) cottonseed meal (CSM, 2.2% fat; 0.4% BW) and 4) no supplementation (CON). The basal diet consisted of low to medium quality chopped grass hay (8% CP; 55% NDF yr 1 and 70% NDF yr 2) fed ad libitum twice daily. Supplements were fed once daily and individual intakes were recorded. Diameter of dominant follicles was measured at TAI via transrectal ultrasonography. Beginning on d 2, blood samples were collected 3x weekly (MWF) to determine plasma progesterone (P4) 4 h after supplementation. Diameter of corpora lutea (CL) was measured on d 13 and 14 after TAI at the same time as Doppler ultrasound analysis of vasculature within the ovarian hilus. Supplemented heifers had greater (P ≤ 0.0001) total DMI than CON heifers. Total CP intake was greater (P ≤ 0.0001) for HDG and LDG compared to CON and CSM was intermediate. Follicles from LDG heifers tended (P = 0.06) to be larger than CSM and CON heifers, but did not differ (P = 0.41) from heifers fed HDG. However, CL diameter and plasma P4 did not differ among treatments (P ≥ 0.26). Ovarian hemodynamics (Pulsatility and Resistance Indices) did not differ (P ≥ 0.35) among treatments and conception rates at d 30 post TAI did not differ (P = 0.98) among treatments (overall 56%). Supplementing heifers with HDG, LDG, or CSM did not influence reproductive measures such as plasma P4, CL diameter, or ovarian hilus vascular resistance when compared with CON.
A 2-yr study was conducted to investigate the effects of protein supplementation with low to medium quality forage diets on yearling heifer performance and plasma AA during early pregnancy. Heifers received timed AI (TAI; d 0) and treatments were fed for 37 d (-7 to +30 from TAI). Angus, Hereford, and Angus-cross heifers (402 ± 42 kg initial BW; n = 79) were stratified by initial BW and BCS and randomly assigned to 1 of 4 protein supplementation treatments formulated to provide similar CP intake; 1) no supplementation (CON); 2) low-fat dried corn distillers grain (LDG, 7.4% fat; 0.8% BW); and 3) high-fat dried corn distillers grains (HDG, 9.5% fat; 0.8% BW); and 4) cottonseed meal (CSM, 2.2% fat; 0.4% BW). The basal diet consisted of low to medium quality chopped grass hay (8% CP; 55% NDF in yr 1 and 70% NDF in yr 2) fed ad libitum twice daily. Supplements were fed once daily prior to hay feeding and individual intakes were recorded. Body weight and BCS was determined at start on (d -9 and -8) and at the end (d 29 and 30). Blood samples were collected 4 h after supplementation d 0, 5, 9, 14, 21, 26, and 30 to determine plasma urea nitrogen (PUN) and AA. Initial BW, initial BCS, and change in BCS did not differ (P 0.80) among treatments; however, overall DMI, and ADG were greater (P 0.0001) for supplemented heifers than CON heifers. Total CP intake was greater (P 0.0001) for HDG and LDG compared to CON and CSM was intermediate. Plasma VAL, LEU, TYR, ILE, TRP, TAUR, total ketogenic AA, and total AA were greater (P 0.05) while GLY was less (P 0.0001) with protein supplementation versus CON. Concentrations of ALA and LYS were less (P 0.0001) from HDG and LDG fed heifers compared to CON and CSM; however, LDG had greater (P= 0.01) LYS concentrations than HDG. Heifers fed CSM had greater (P 0.05) ARG and ASP. Concentrations of THR were greater (P= 0.0004) for LDG and CSM. Protein supplementation increased (P 0.0001) PUN in supplemented heifers compared to CON. Protein supplementation during early pregnancy in beef heifers resulted in greater protein intake and increased circulating PUN and total AA.
The influence of relative maternal undernutrition on growth, endocrinology, and metabolic status in the adolescent ewe and her fetus were investigated at Days 90 and 130 of gestation. Singleton pregnancies to a single sire were established, and thereafter ewes were offered an optimal control (C; n = 14) or low (L [0.7 × C]; n = 21) dietary intake. Seven ewes receiving the L intake were switched to the C intake on Day 90 of gestation (L-C). At Day 90, live weight and adiposity score were reduced (P < 0.001) in L versus C dams. Plasma insulin and IGF1 concentrations were decreased (P < 0.02), whereas glucose concentrations were preserved in L relative to C intake dams. Fetal and placental mass was independent of maternal nutrition at this stage. By Day 130 of gestation, when compared to C and L-C dams, maternal adiposity was further depleted in L intake dams; concentrations of insulin, IGF1, and glucose were reduced; and nonesterified fatty acids increased. At Day 130, placental mass remained independent of maternal nutrition, but body weight was reduced (P < 0.01) in L compared with C fetuses (3555 g vs. 4273 g). Body weight was intermediate (3836 g) in L-C fetuses. Plasma glucose (P < 0.03), insulin (P < 0.07), and total liver glycogen content (P < 0.04) were attenuated in L fetuses. Fetal carcass analyses revealed absolute reductions (P < 0.05) in dry matter, crude protein, and fat, and a relative (g/kg) increase in carcass ash (P < 0.01) in L compared with C fetuses. Thus, limiting maternal intake during adolescent pregnancy gradually depleted maternal body reserves, impaired fetal nutrient supply, and slowed fetal soft tissue growth.
The objective of this study was to evaluate low-medium quality intake and apparent total tract digestibility supplemented with of low-fat vs. high-fat corn dried distillers grains with solubles (DG) in yearling Angus, Hereford, and Angus-cross beef heifers (n = 30; 399 ± 16 kg). Heifers were stratified by BW and breed composition and then assigned to 1 of 3 treatments: (1) no supplementation (CON); (2) supplementation of low-fat DG (LDG; 5.04% EE); (3) supplementation of high-fat DG (HDG; 9.09% EE). Heifers were provided ad libitum intake of low to medium quality chopped grass hay (7.82% CP; 1.14 Mcal NEm/kg). Both LDG and HDG were supplemented at 0.8% body weight (BW) to provide a similar CP intake of 0.22% of BW. Hay was fed twice a d at 0800 and 1600 and supplement was fed once a d before hay feeding at 0700. Individual feed intake was recorded for 37 d. Two-day BW were collected at the beginning and end of the trial. To determine apparent total tract digestibility feed-offered, feed refusals, and fecal grab samples were collected on d 27 from a subset of 3 heifers per treatment and then DM, OM, CP, ADF, NDF, and EE analysis was performed and ADIN was used an indigestible marker. Heifers supplemented with DG (LDG or HDG) had greater BW gain and ADG (P < 0.0001) and lower (P = 0.002) total DMI in g/kg of BW compared with CON, however no differences were detected (P ≥ 0.14) in BW gain, ADG, or total DMI in g/kg of BW between HDG and LDG. Furthermore, a change in BCS was not detected (P = 0.46) among treatments. Heifers that were supplemented LDG had lower DM, N, and NDF apparent digestibility than heifers supplemented HDG and heifers with no supplementation (P ≤ 0.004). Apparent digestibility of OM and ADF did not differ among treatments (P ≥ 0.05) while heifers supplemented LDG had lower apparent digestibility of EE (P = 0.001) and HDG supplementation was intermediate as compared with CON. Supplementation of DG regardless of fat content reduced total DMI and improved BW gain for yearling beef heifers, but supplementing the LDG vs. HDG resulted in lower DM, N, and NDF digestibility fed with low to medium quality grass hay.
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