Research Council Requirements Research Articles

PSX-A-16 Late-Breaking: Maternal nutrient restriction and re-alimentation influences liver protein expression in fetal sheep

Abstract To determine the effects of maternal nutrient restriction and re-alimentation on the fetal liver proteome, 48 pregnant ewes with singletons were fed a control diet [100% National Research Council (NRC) requirements (CON)] starting at the beginning of gestation. On day 50 of gestation, a subset of ewes were fed either CON or 60% NRC requirements (RES). A subset of ewes were euthanized at day 90 of gestation (n = 7/treatment), and fetal liver samples collected. Remaining ewes were maintained on the current diet (CON-CON, n=6; RES-RES, n = 7) or switched to alternative diet (CON-RES, RES-CON; n=7/treatment). On day 130 of gestation, remaining ewes were euthanized, and fetal samples collected. Fetal liver proteins were extracted, digested by trypsin and subjected to multiplexed, label-based quantitative mass spectrometry analysis integrating Tandem Mass Tags. Proteins were identified and quantified using Proteome Discoverer (v2.5, Thermo Scientific) and differential abundance analysis was performed using ANOVA and post hoc Tukey’s HSD test. Hierarchal clustering analysis showed clustering of treatments by day of gestation. However, differences were also observed between treatments. At day 90 of gestation, 23 proteins were differentially expressed in RES compared with CON among which glycyl tRNA synthetase and pyruvate carboxylase were increased 12% and 10%, respectively (P < 0.03). At day 130 of gestation, 24, 5, and 71 proteins were differentially expressed in CON-RES, RES-CON, and RES-RES, respectively, compared with CON-CON. Carnosine dipeptidase 2 was decreased 7% in CON-RES and rho associated protein kinase and glycogen synthase 2 were increased 20% and 26% in RES-CON and RES-RES, respectively, compared with CON-CON (P < 0.04). These results indicate that nutrient restriction during mid- and late-gestation impacts expression of proteins involved in gluconeogenesis, glycogenesis, and the formation of carnosine, an integral molecule in beta-oxidation, and that re-alimentation alters proteins involved in cell migration pathways. Supported by USDA-AFRI grants 2016-67016-24884 and 2017-67016-26568.

PSIV-16 Maternal Nutrient Restriction Followed by Re-alimentation Alters Distinct Metabolic Pathways in Sheep Offspring

Abstract To determine the effects of maternal nutrient restriction and re-alimentation on offspring metabolism, 48 pregnant ewes with singletons, were fed a control diet [100% National Research Council (NRC) requirements (CON)] starting at the beginning of gestation. On day 50 of gestation, ewes (n = 7) were euthanized and fetal liver, muscle, and blood samples were collected. The remaining animals were fed either CON or 60% NRC requirements (RES), a subset were euthanized at day 90 of gestation (n = 7/treatment), and fetal samples obtained. Remaining ewes were maintained on the current diet (CON-CON, n = 6; RES-RES, n = 7) or switched to alternative diet (CON-RES, RES-CON; n = 7/treatment). On day 130 of gestation, remaining ewes were euthanized, and fetal samples collected. Fetal liver, longissimus dorsi, and blood metabolites were analyzed using LC-MS/MS at Metabolon Inc. Pathway enrichment analysis was conducted using MetaboAnalyst 4.0. In liver, muscle, and blood, 64, 44, and 34 pathways were enriched between treatments at day 130 gestation and 10, 6, and 11 pathways were enriched at day 90 gestation, respectively. Arginine and proline metabolism; primary bile acid biosynthesis; and valine, leucine, and isoleucine biosynthesis were the most highly enriched pathways in RES compared with CON in liver, muscle, and blood, respectively. Additionally, the pentose phosphate pathway; valine, leucine, and isoleucine metabolism; and phenylalanine metabolism were the most highly enriched pathways in RES-CON compared with CON-CON in liver, muscle, and blood, respectively. In liver, ribulose 5-phosphate, xylulose 5-phosphate, and ribose 5-phosphate were decreased 1.82-, 1.54-, and 2.38-fold, respectively in RES-CON compared with CON-CON (P ≤ 0.05). Total triacylglycerols were increased 3.04-fold in muscle and decreased 1.57-fold in blood in RES-CON and RES-RES compared with CON-CON and CON-RES (P ≤ 0.05). Mid-gestational nutrient restriction and subsequent re-alimentation altered distinct metabolic amino acid, carbohydrate, and lipid pathways, potentially altering postnatal growth. Supported by USDA-AFRI grants 2016-67016-24884 and 2017-67016-26568.

Flock differences in the impact of maternal dietary restriction on offspring growth and glucose tolerance in female offspring

Variable impacts of in-utero programming stimuli on postnatal offspring development suggest that genotype may play a role in this response. In this study, ewes from two flocks of similar breeding but adapted for 6-8 generations to one of two markedly different production environments were utilized (Baggs ewes--nomadic lifestyle and limited nutrition; UW ewes--sedentary lifestyle and adequate nutrition). Ewes from each flock were fed 50% (nutrient restricted) or 100% (control) National Research Council (NRC) requirements between day 28 and 78 of gestation; some ewes in each dietary group were then necropsied. Remaining ewes were fed 100% NRC requirements from day 79 to term. Weights of singleton female fetuses were reduced (P < 0.05) in nutrient restricted UW ewes compared to control UW ewes on day 78. Two month old ewe lambs from nutrient restricted UW ewes had greater (P < 0.05) baseline glucose concentrations, and exhibited greater (P < 0.05) glucose and insulin concentrations to an intravenous glucose bolus than lambs from control UW ewes. From 4 to 12 months of age, ewe lambs from nutrient restricted UW ewes were heavier (P < 0.05) than lambs from control UW ewes. In contrast, no differences in fetal weight, baseline glucose, glucose and insulin concentration to an intravenous glucose bolus, or body weight were observed for nutrient restricted and control Baggs ewes. These data suggest that a multigenerational adaptation of ewes to different production systems impacts their ability to protect their fetus against a bout of early to mid-gestational nutrient restriction.

Effect of Stepped Pattern of Feed Intake Using Rice Straw as Roughage Source on Regulation of Growth, Reproduction and Lactation in Dairy Heifers

An attempt was made to improve the efficiency of growth and lactation performance of dairy heifers subjected to a stair-step growth scheme using rice straw as the sole roughage source. Twenty-four young Holstein heifers were randomly assigned to either control or test group. The control diet met the National Research Council (NRC) requirement, with heifers calving at 24 to 26 mo of age. The test group was individually fed according to a schedule of 3, 2, 4, 2, 5 and 2 mo in which feed intake was alternately 20% below or 25% above the NRC requirements. Heifers on the stair-step growth pattern gained more body weight and consumed less dry matter (10.80 and 11.22%, respectively), resulting an increasing growth efficiency compared with the control. Body condition, first estrus, first conception, services per conception and calving difficulty (data not shown) were not affected. Milk yield of the test group was 8.5% higher than that of the control group. During the early lactation period, the milk yield was significantly higher in the stair-step group than in that of the control group (p<0.05). Milk composition was not affected by compensatory growth induced by the stair-step scheme. Also, weight at calving and calf growth performance was not affected by stair-step growth. The results indicate that using rice straw as a sole roughage source in a stair-step compensatory growth scheme can contribute to the improvement of growth efficiency and early lactation performance. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 6 : 794-798)

An innovative approach to integrating engineering design The Newcastle Engineering Design Centre

This paper describes how the innovative idea of an Engineering Design Centre (EDC) has been used to integrate academia, industry and government to build a highly successful internationally respected design research base. We restrict our description to the marine, offshore, civil and structural engineering areas and show how the research council's requirements for innovative design were met at the Newcastle EDC, the biggest and most successful of the United Kingdom's EDC's.

Physical or Temporal Separation of Olestra and Vitamins A, E and D Intake Decreases the Effect of Olestra on the Status of the Vitamins in the Pig , ,

A study was conducted in the domestic pig to determine 1 ) whether feeding olestra mixed in the diet exaggerated olestra effects on fat-soluble vitamin status compared with the effects of feeding it in a typical snack food, and 2 ) whether separating olestra consumption temporally from vitamin consumption affected the influence of olestra on vitamin status. Groups of 10 pigs each, five castrated males and five females, were fed 2.2% (wt/wt) olestra for 4 wk in purified diet that provided 1 time the National Research Council's requirements for swine of all micronutrients. The olestra was either mixed in the purified diet or fed in potato chips. The potato chips were given to the pigs at all three feedings, at the noon feeding only, or between the noon and the evening feedings. A control group was fed the purified diet with no olestra. The effects of olestra on indices of vitamin A, D and E status were from 1.7 to 4.5 times greater when olestra was fed three times daily mixed in the diet than when it was fed three times daily in potato chips. Because the effect of olestra on the status of the fat-soluble vitamins was diminished substantially by feeding the olestra in potato chips, it was not possible to conclude definitively how the temporal separation of olestra and vitamin consumption affected the olestra effect on vitamin status.

Tolerance of young pigs for dietary vitamin A and μ-carotene, with special reference to the immune response

Guidelines need to be drawn up for the fortification of diets with vitamin A, because of its known toxicity. In exp. 1, 35 pigs aged 5 wk and weighing about 10 kg were placed in individual cages and allocated to seven dietary treatments for 28 d. In treatments 1–6 the levels of vitamin A or β-carotene represented 1, 10 or 100 times the National Research Council (1988) requirement for vitamin A, and in treatment 7 vitamin A and β-carotene were combined 50:50 to provide a total representing 100 times the vitamin A requirement. The vitamin A biopotency of β-carotene was assumed to be 200 IU mg−1. There was no significant effect of vitamin A or β-carotene on growth performance, plasma Escherichia coli antibody, or on lymphocyte proliferation. Serum retinol at 14 and 28 d increased as the level of dietary vitamin A increased but the effect was not significant (P = 0.241 and 0.073, respectively), β-carotene gave higher serum retinol at 14 and 28 d than vitamin A, but the effect was not significant (P = 0.232 and 0.059, respectively). Liver retinol increased with increasing level of dietary vitamin A or β-carotene (P &lt; 0.001). In exp. 2, 30 pigs aged 5 wk and of 10 kg initial weight were penned in groups of three, injected i.m. and 3 wk later with 2 mL of a commercial TGE vaccine, and were fed for 5 wk on diets containing graded levels of vitamin A representing 0, 1, 10, 100 and 200 times the requirement. Growth performance was not significantly affected by treatment, nor was the morphology of tissues integral to the immune system. Anti-TGE titre increased markedly after the second injection of vaccine, but was not affected at any stage by treatment. Serum retinol increased significantly (P &lt; 0.002) and serum tocopherol was reduced significantly (P &lt; 0.001) with increasing dietary vitamin A. The data fitted a cubic model. Liver retinol was increased significantly (P &lt; 0.001) and liver tocopherol was reduced significantly (P &lt; 0.001) with increasing dietary vitamin A. The data fitted a cubic model. These results show that increasing dietary vitamin A raises both the circulating and storage levels of retinol, and that the response may be predicted from the equations derived. The results also show that increasing dietary vitamin A has a significant depressing effect on vitamin E status. Taken in conjunction with previous findings from our laboratory, the results suggest that the tolerable dietary range of vitamin A for the young pig in the weight range 10–30 kg is up to 10 times the requirement. Key words: imunity, pig, β-carotene, toxicity, vitamin A, vitamin E

Alterations in calcium intake on peak bone mass in the female rat

This study compared the effect of a calcium deficit or surfeit on bone growth and development in the early phase of peak bone mass attainment with the late phase of peak bone mass attainment using the female Sprague-Dawley rat as a model. Groups of weanling animals were fed one of three nutritionally complete but calcium-altered diets (0.25%, 0.5%, or 1.0% calcium) for 8 weeks. Animals within each diet group were then rerandomized into one of the above diets and fed until 37 weeks of age. Each group contained five rats. In addition, three groups that received the 0.25% calcium diet for the first 8 weeks remained on the diet until week 20 when they were further randomized into one of the three diet groups and fed until 37 weeks of age. Results of this experiment indicate that increasing the calcium intake after adolescence (12-weeks-old) of those female rats consuming a low calcium diet will not substantially alter the adult bone volume of the metaphyseal region of the proximal tibia. Further, low calcium intakes through adolescence retard and prolong longitudinal bone growth. In contrast, however, those rats fed a diet providing calcium either at (0.5%) or twice the National Research Council's requirement level through adolescence had greater tibial bone volume as an adult when fed diets containing 1.0% calcium after this time period. It appears that the mechanism for this increase involves both a protection from resorption and an increase in bone formation/mineralization. This study is the first to show that low calcium intakes through adolescence have a nonreversible, deleterious effect on peak bone mass, whereas higher intakes promote greater peak bone mass and provide potential protection from age-related bone loss.

Effect of Reovirus Infection and Dietary Levels of Selected Vitamins on Immunocompetence of Chickens

The immunocompetence of 8-week-old reovirus WVU 2937-infected and uninfected chickens fed various dietary levels of biotin, niacin, choline, or folic acid was evaluated in four experiments. Antibody production to sheep red blood cells (SRBC), wattle responses to phytohemagglutinin-P (PHA-P), and wattle responses of tuberculin-sensitized chickens to bovine-purified protein derivative (PPD) were examined in five chickens per treatment. Dietary deficiencies had no effect on the in vivo T-cell immune responses to PPD, PHA-P, or humoral hemagglutinating-antibody production to SRBC. Reovirus-infected and uninfected chickens fed biotin at double the National Research Council (1977) requirement demonstrated decreased PPD responses. Lower hemagglutinating-antibody titers in the uninfected chickens and increased titers in the infected chickens were observed in those fed 200% of the requirement of biotin when compared with the chickens fed 20% and 100% biotin diets. Reovirus infection had no effect on PPD and PHA-P responses. However, in the choline experiment, reovirus-infected chickens had elevated titers. These data indicate that reovirus infection had no adverse effect on the immunocompetence of chickens 8 weeks postinfection. Dietary deficiencies also had no adverse effect on the immunocompetence of 8-week-old reovirus-infected and uninfected chickens.

The phosphorus requirements for growth and maintenance of sheep

SUMMARYPhosphorus requirements for maintenance and growth were assessed by giving to growing lambs and non-pregnant ewes diets low in P and to growing lambs a diet containing the quantity of P recommended by the Agricultural Research Council (1980).Seven 14-week-old lambs were given ad libitum a pelleted diet containing 1·88 (LP) or 2·75 (NP) g P/kg D. M. for 13 weeks. There was no effect of P intake on feed intake or growth during the first 8 weeks when the P intake of the LP groups was 1·07 of Agricultural Research Council (1980) requirements. During the last 5 weeks the P intake of the LP group was only 0·87 of Agricultural Research Council (1980) requirements and growth and feed intake were higher in the male but not female lambs in the NP group. From the 3rd week the plasma concentration of P was significantly lower (P &lt;0·001) in the LP group. Mineralization of selected bones was less in the LP group.After 14 weeks on the diet, balance trials with 32 P were carried out on the lambs from each dietary group. P intakes ranged from 1 to 3 g/day. An additional balance trial was undertaken with eight 2-year-old female sheep consuming a hay diet (1·5 g P/day).The endogenous faecal excretion of P by the growing lambs on the LP diet and ewes was 12·2 ± 0·8 and 12·7 ± 1·00 mg/kg live weight/day respectively, very close to the value (12 mg/kg live weight/day) adopted by the Agricultural Research Council (1980). The absorbability of the P in the concentrate and hay diets was 0.71 ±0·267 and 0·74 ± 0·0218 respectively, the former agreeing with and the latter higher than the corresponding value for Agricultural Research Council (1980).

Production, Digestibility, and Perloline Content of Fescue Stockpiled and Harvested at Different Seasons1

AbstractThe management of tall fescue (Festuca arundinacea Schreb.) to utilize spring, summer, or early fall production in summer, fall, or early winter, could help harmonize livestock pasture requirements with available forage supply. Such utilization must be accomplished without appreciable loss of quality. The effects of several stockpiling schemes (spring, summer, late summer, fall, and spring + fall) on tall fescue dry matter yield, in vitro digestible dry matter (IVDDM), and perloline and total N contents were investigated over a 3‐year period. Nitrogen at the rate of 50 kg/ha was applied in March and September each year. Yield or composition of stockpiled material was not different when fescue was removed gradually or as a single hay cut, and the year × treatment interaction was not significant. Stockpiling did not affect production at other times of the year. Stockpiling made 3,700, 1,300, 650 and 1,000 kg/ha more dry matter available than continuous clipping in summer, early fall, late fall, and winter from spring, early summer, late summer, and fall stockpiling, respectively. Total N content of stockpiled herbage sometimes was lower than the National Research Council's requirement for a lactating beef cow and, occasionally, for a dry beef cow. Herbage stockpiled in spring, in early summer, and in late summer, had 45, 49, and 59% IVDDM, respectively. Fall‐stockpiled herbage had IVDDM in excess of 60%. The perloline content of stockpiled fescue was low (&lt;0.16 mg/g), but summer regrowth after stockpiling removal had a relatively large alkaloid content (0.46 mg/g). Although the largest yields of stockpiled forage resulted from spring accumulations, the quality was low. Lowest quality was measured in forage accumulated in summer. Stockpiling in late summer or early fall produced sufficient material to extend the grazing season several weeks into winter.

THE EFFECTS OF INTRAVENOUS INFUSION OF LYSINE, LYSINE PLUS METHIONINE OR CARNITINE ON PLASMA AMINO ACIDS AND MILK PRODUCTION OF DAIRY COWS

Four lactating Holstein cows were each infused intravenously for periods of up to 9 days with solutions of L-lysine (15 g/day), L-lysine plus D,L-methionine (15 + 10 g/day) D,L-carnitine (20 g/day) or physiological saline. The cows were fed a ration of 2 kg chopped hay (14.8% crude protein), corn silage ad libitum (8.0% crude protein) and a concentrate mixture (16.5% crude protein) (1 kg/3 kg milk). Daily digestible protein intake was 1.85 kg/cow or 87% of calculated (National Academy of Sciences – National Research Council) requirements. There was no significant effect of infusion treatment on intake of corn silage, milk yield and composition or digestibility of the ration. The efficiencies of conversion of dietary protein to milk protein were 38.4, 38.6, 36.6 and 37.8% and nitrogen balances were 6, −2, 8 and 5 g/day for saline, lysine, lysine plus methionine and carnitine infusions. The concentration of carnitine in the milk was greater when carnitine was infused but was unaffected by the infusion of lysine and methionine. Plasma lysine and methionine were increased when these amino acids were infused. On the basis of plasma amino acid patterns it was concluded that methionine, lysine and threonine were possibly the most limiting amino acids under the conditions of this experiment and that in combination with a less than adequate energy intake (i.e. 87% of calculated requirements), infusion of lysine and methionine failed to give a response in production.

Nitrogen Metabolism and Metabolic Fecal Nitrogen as Related to Caloric Intake and Digestibility

Six Holstein bull calves were used in each of two trials to evaluate nitrogen metabolism of the young ruminant. Two replicas of a 3 × 3 Latin square experiment were in each trial. In Trial 1, three isonitrogenous rations were formulated to differ in dry matter digestibility by substitution of 10, 20, and 30% powdered polyethylene plastic for corn starch. All rations were fed at 2.7 kg/100kg body weight. Digestible energy intake was below the National Research Council's requirements for calves receiving the 20 and 30% polyethylene rations. For Trial 2, three similar rations were formulated to contain 0, 11, and 22% plastic. Crude protein and digestible energy content of these rations decreased with added plastic, but feeding rates were increased accordingly to provide equal protein and adequate digestible energy. Five- or seven-day nitrogen balances were measured for all calves with allowance of a 2-week adjustment during ration changes.Fecal nitrogen was not altered by fecal dry matter changes in Trial 1. A linear increase in urinary nitrogen indicated that calves in Trial 1 used absorbed protein as an energy source. In Trial 2, fecal nitrogen increased linearly with added plastic to reflect a component of the metabolic fecal nitrogen increment which was 4.58g per kilogram of fecal dry matter output. Metabolic fecal nitrogen is affected by energy balance of the animal as well as by digestibility of the ration.

LIGHTING AND CYANOSIS

The frequency with which observers detected cyanosis at differing arterial oxygen saturation levels has been estimated in postoperative patients recovering from anaesthesia. The frequency in the light of a fluorescent tube, which meets the Medical Research Council's requirements, has been compared to that obtained using an examination lamp fitted with a tungsten filament bulb. There was no significant difference between the results obtained in the two lighting conditions. The differences in the frequencies of cyanosis examined at 5 per cent arterial oxygen saturation intervals were highly significant.