Adequate Growth Rate Research Articles

Follow-up of children and adolescents with short stature: the importance of the growth rate

Short stature is defined as a height of more than two standard deviations below the average for a given age and sex in a reference population. The objective was to describe follow-up conducted among short-stature children and adolescents. Descriptive study, at the Growth outpatient clinic, Department of Pediatrics, Universidade Federal de São Paulo. The study included 152 patients aged 2 to 15 years who had height for age of less than P5, on the National Center for Health Statistics curve. The children underwent nutritional evaluation, and several variables relating to height and growth rate were calculated to establish etiological diagnosis. Bone age was evaluated by X-ray. The majority (63.2%) were male. In 77.8%, the stature observed was within the family pattern. Among the 99 patients followed up for more than 6 months, 17.2% presented inadequate growth rates. The preponderant etiological diagnosis for short stature was familial/constitutional in 58.6% of the cases; 27 patients (34.2%) with adequate growth rate presented bone age alterations. Even with inadequate growth rates, 75% of such patients had a normal result from growth hormone stimulation testing. Close to 90% of patients with a diagnosis of short stature of familial/constitutional origin and intrauterine growth retardation presented adequate growth rate. The genetic etiology was significantly characteristic of patients with inadequate growth rate. Growth rate assessment must form part of the investigation and follow-up of short-stature cases. However, its utilization and validity should form part of an overall view of each patient.

Quantifying geographic variation in physiological performance to address the absence of invading species

:An estuarine snail (Batillaria attramentaria), introduced to northern California marshes, is displacing a native confamilial mudsnail (Cerithidea californica) through superior competition for shared, limiting food resources. Batillaria, however, is absent from similar marsh habitats in southern California. I tested whether regional-scale variation in relative performance (growth) of the snails may have influenced Batillaria’s invasion pattern. I quantified growth using RNA:DNA ratios (a growth index that I ground-truthed with direct growth measurements) for snails collected throughout their entire collective North American distribution. Batillaria exhibited a high growth rate that was more than double Cerithidea’s growth rate in sympatric populations. A broad-scale relationship of species’ growth rates against latitude projected an amply adequate growth rate for Batillaria in southern California where it is presently absent. Furthermore, growth rates of Cerithidea did not increase in southern California, suggesting that Batillaria would maintain its dramatic relative performance advantage. Thus, even if resources are limiting at southern latitudes, biotic resistance through competition with Cerithidea does not explain Batillaria’s absence. Among alternative, untested hypotheses for Batillaria’s absence, insufficient propagule inoculation has strongest support. Because transplant experiments with nonindigenous species are unethical, examination of species’ performance over geographic scales provides a powerful alternative approach for invasion studies.

Application of a low oil pre-harvest diet to manipulate the composition and quality of Atlantic salmon, Salmo salar L.

A trial was undertaken to evaluate a low oil pre-harvest feed (LOW, 50% crude protein, 18% crude fat) as a means of manipulating the quality of Atlantic salmon growing between 2.5 and 4.5 kg in the spring/summer. For the preceding 14 months, the salmon consumed commercial-style feeds, which varied in protein and oil content (CON); feeds with variable but relatively lower lipid/protein ratios (RET); feeds with variable but relatively higher lipid/protein ratios (ADV) or feeds with a fixed, low oil/protein ratio (LOW). During the 70-day pre-harvest period, salmon previously given the CON, RET and LOW feeds were fed the LOW diet while those fed the ADV feeds were fed a high energy diet (HIGH; 40% crude protein, 36% crude fat). Salmon fed the HIGH feed achieved an SGR (0.34% day −1) higher than that of salmon switched to the LOW feed (CON/LOW and RET/LOW). Fish on the LOW/LOW regime were initially smaller than the others but underwent a period of catch-up growth (SGR=0.40% day −1) and at harvest, these fish were not significantly smaller than salmon fed the CON feeds for 14 months followed by the LOW feed for 70 days. Irrespective of the feeds fed in the preceding 14 months, feeding the LOW feed for 70 days resulted in condition factors (1.13–1.14) that were significantly lower than for the fish fed the HIGH feed (1.20). With the exception of fish on the LOW/LOW regime, carcass yields improved significantly during the pre-harvest period irrespective of the feed fed and there were no significant differences in carcass yield at harvest. Salmon fed LOW feeds from smolt input until harvest were the leanest (9.3% fat in fillet portion). There was a significant reduction in the fillet fat percentage of fish on the CON/LOW regime (reduced from 12.9 to 11.2%) but no significant effect amongst fish on the RET/LOW regime (11.8%). Salmon switched to the LOW feed pre-harvest were significantly leaner than those fed the HIGH feed (13.8%). There were no significant differences in perceived flesh colour (Roche SalmoFan™) at harvest and using the low oil, pre-harvest feed did not significantly improve instrumentally measured colour. By applying a low oil, pre-harvest feed, an adequate growth rate and FCR could be achieved for the majority of the production cycle and by manipulating the quality of the fish nearer to harvest, greater flexibility would be achieved, allowing the producer to tailor the fish to the specific fat/condition factor requirements of the market at the time of harvest.

Performance of Broiler Chicks Fed Normal and Low Viscosity Rye or Barley with or without Enzyme Supplementation

This experiment was conducted to measure nutrient digestibility and performance in broiler chicks fed diets based on normal and low viscosity rye or barley fed with and without enzyme (pentosanase and β-glucanase) during a 17 day growth trial. A total of 150 one-day old, male broiler chicks (5 birds per pen and 5 pens per treatment) were randomly assigned to one of six dietary treatments in a 3×2 factorial design experiment (3 cereals×2 enzyme levels). Digestibility coefficients were determined using chromic oxide. Digestibility coefficients for dry matter and crude protein were significantly (p=0.0001) higher for the barley-based diets than for any of the rye-based diets. Digestibility coefficients for gross energy did not differ (p>0.05) due to cereal grain. There were no differences in the digestibility coefficients for dry matter and gross energy between chicks fed normal and low viscosity rye. However, the digestibility coefficient for crude protein was higher (p=0.01) for the low viscosity rye compared with the normal viscosity rye. Addition of enzyme to the diet significantly (p=0.0001) increased digestibility coefficients for dry matter, crude protein and energy. There were no significant differences in weight gain, feed intake or feed conversion between birds fed barley or rye or between birds fed normal or low viscosity rye. Enzyme supplementation significantly improved (p=0.0001) weight gain, intake and feed conversion. The overall results of this experiment indicate that unsupplemented barley and rye do not support adequate growth rates in poultry. Enzyme supplementation dramatically improved broiler performance. In addition, genetic selection to reduce the viscosity of rye had only a modest effect on the nutritive value of rye for broilers. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 2 : 234-238)

Protein supplementation of human milk for promoting growth in preterm infants

For term infants, human milk provides adequate nutrition to facilitate growth, as well as potential beneficial effects on immunity and the maternal-infant emotional state. However, the role of human milk in preterm infants is less well defined as it contains insufficient quantities of some nutrients to meet the estimated needs of the infant. Preterm infants require higher protein intakes than term infants to attain adequate growth rates, and have relatively higher protein turnover rates. Inadequate protein intakes may be partly responsible for low serum albumin and blood urea concentrations in preterm infants. The main objective was to determine if addition of protein to human milk leads to improved growth and neurodevelopmental outcomes without significant adverse effects in preterm infants. The standard search strategy of the Cochrane Neonatal Review Group was used. This includes searches of the Oxford Database of Perinatal Trials, MEDLINE, previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, and journal handsearching mainly in the English language. All trials utilizing random or quasi-random allocation to supplementation of human milk with protein or no supplementation in preterm infants who remained in hospital were eligible. Data were extracting using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author and synthesis of data using relative risk and weighted mean difference. Protein supplementation of human milk results in increases in short term weight gain (WMD 3.6 g/kg/day, 95% CI 2.4 to 4.8 g/kg/day), linear growth (WMD 0.28 cm/week, 95% CI 0.18 to 0.38 cm/week) and head growth (WMD 0.15 cm/week, 95% CI 0.06 to 0.23 cm/week). There are insufficient data to evaluate long term neurodevelopmental and growth outcomes. There are too few infants studied to be certain that adverse effects of protein supplementation are not increased. Blood urea levels are increased (WMD 1.0 mmol/l, 95% CI 0.8 to 1.2 mmol/l). Protein supplementation of human milk in relatively well preterm infants results in increases in short term weight gain, linear and head growth. Urea levels are increased, which may reflect adequate rather than excessive dietary protein intake. Further research should be directed towards the evaluation of specific levels of protein intake in preterm infants and the clinical effects of supplementation with protein, including long term growth and neurodevelopmental outcomes. This may best be done in the context of refinement of available multicomponent fortifier preparations.

Modeling biases in estimating production from copepod cohorts

Production (P) by copepod cohorts between sample times 0 and t is estimated from cohort numbers (N 0 and N,) and biomasses (B 0 and B 1 ) as P = (1 + m/g)ΔB, where m = ln(N 0 /N 1 ), g = ln(B t /B 0 ), and AB = B t - B 0 . This equation assumes exponential changes in biomass and numbers during the interval. Individual-based simulation models show that variances in initial weights and growth rates do not bias estimates; only severe size (stage) dependence of growth rates introduces serious bias; extreme size dependence of mortality rates produces more bias, mitigated by more frequent sampling; negative size dependence of both growth and mortality rates tends to cancel biases; and underestimation of production when individuals accumulate in nongrowing stages is mitigated by sampling when such individuals first appear. With these qualifications, the above equation is adequate and detailed mortality and growth rates of individual stages are unnecessary when cohorts are distinguishable.

Barley grass seed and shearing effects on summer lamb growth and pelt quality

The effects of mature barley grass (Hordeum spp.) pasture on lamb growth rates, carcass180 crossbred lambs finished on summer pastures. The effect of shearing at weaning, using 2 types of combs (traditional or cover) was compared with a 'no shearing' treatment.Exposure to barley grass pasture over November and December produced growth rates of 82 � 5 g/day for lambs slaughtered in January compared with growth rates of 141 � 5 g/day on lucerne pasture over the same period. On the barley grass pasture, shearing gave an immediate and sustained advantage (P<0.05) in growth rate but no difference between cover or traditional comb. Carcass weights were 21.4 � 0.3 and 19.0 � 0.4 kg for lambs grazing lucerne pasture and barley grass pasture, respectively. Shearing reduced pelt damage from barley grass seed to the extent that 85% of unshorn pelts had >5 scars per pelt compared with 13% in pelts from shorn lambs. Type of shearing comb did not influence the result. The results suggest that maturing barley grass pastures must be avoided if adequate growth rates are to be achieved in weaner lambs.

Control of Protein Synthesis and Its Relationship to the Bioenergetics of Growth

A key goal of nutritional therapies designed to prevent or treat protein energy malnutrition (PEM) is achievement of adequate growth rates and thus positive balances of protein and energy. Positive protein balance is the net result of protein turnover, i.e., of recycling protein through energy-requiring anabolic and catabolic pathways. Thus, protein turnover is inexorably linked to energy metabolism and to energy balance. A long-standing hypothesis is that new tissue synthesis is predominantly a postprandial event. Thus, postprandial rates of protein turnover may regulate the bioenergetics of growth. Traditional methods to evaluate nutritional therapies for diarrhea and PEM, i.e., metabolic balance, 15N-labeled amino acids, fecal output, illness duration, or change in body weight, are not specific to studies of the regulation of acute protein turnover and growth by nutritional intervention. Newer techniques based on 13C-labeled amino acids should be applied to evaluate nutritional interventions such as dietary substrate ratios, protein quality, feeding frequencies, or ratios of dietary protein to energy in terms of their abilities to optimize postprandial protein turnover and thus nutritional management of diarrhea or PEM.

INFLUENCE OF BREED OF SIRE, DIETARY INTAKE AND HOUSING FACILITIES ON THE ATTAINMENT OF PUBERTY IN CROSSBRED GILTS

The role of diet intake and type of confinement pen in the stimulation of puberty was determined with 483 gilts from a Landrace (L) × Yorkshire (Y) rotational cross over 4 yr. At 160 d of age, gilts were housed either in stalls (S) or groups (G) of eight per pen. They were fed a diet intake level to provide approximately 0.4 kg gain d−1 for the duration of the experiment (C) or 0.0 kg d−1 for the first 2 wk (R) and then as for C. Gilts were checked for estrus once daily with vasectomized boars. AU S gilts had 30 min d−1 of in-pen exposure to mature boars, while G gilts had constant pen line exposure to mature boars. Over the 8-wk period 73.5% of the gilts attained puberty. Diet intake restriction and group penning had similar effects on the mean interval to puberty, with C and R gilts averaging 13.6 ± 1.0 and 17.4 ± 1.0 d (P < 0.01), and S and G gilts averaging 12.3 ± 0.9 and 18.7 ± 1.1 d (P < 0.01). Both the Rand G treatments resulted in a delay in the attainment of puberty as compared to S-penned C gilts. This difference was apparent within 3 d. The delay in puberty associated with diet intake restriction was found only in S-penned gilts and was eliminated 10 d after the R gilts were placed on the C level of diet intake. The group penning delay in attaining puberty was evident for 31 d in Y-sired gilts and to the end of the experiment in L-sired gilts. In L-sired gilts 85.3 and 55.6% of the S and G gilts, respectively, attained puberty (P < 0.05) as compared to 74.6 and 76.9% of the Y-sired gilts. Thus, the ability of the gilt to attain puberty in response to boar exposure is dependent on the breed of gilt, diet intake and pen type, with stalls and an adequate growth rate required for the greatest response. Key words: Gilts, puberty, breed, diet intake, pen type

Fertilising Commercial Forest Species in Southern Africa: Research Progress and Problems (Part 1)

SYNOPSIS Since the inception of forest fertiliser research in Southern Africa in 1926, eight eucalypt, six pine and four acacia species have been tested, encompassing a wide range of sites in summer, winter and uniform rainfall areas. Marked deficiencies of P, Mn and sometimes N, usually associated with hydromorphic and elluviated soils derived from sandstone, are easily diagnosed and corrected at planting or after canopy closure. On the other hand, ferralitic soils showing adequate growth rates respond mainly to applications of P and Ca but balanced for N and K at planting. However, requirements after canopy closure are difficult to determine, varying with site, species and stand development. Fertilising at planting promotes the development of a vigorous root system, which allows for continually improved growth. Thus responses increase with the effective rooting depth and soil water availability of sites, as well as being larger for the faster growing species. Hence MAI has been increased up to 11 m3/ha ...

Intensive Culture of Larval Walleyes with Dry or Formulated Feed: Note on Swim Bladder Inflation

Abstract Two experiments were conducted to test the effects of modified feeding techniques and three dry or formulated diets on the survival, growth, and swim bladder inflation of larval walleyes (Stizostedion vitreum). In experiment 1, duplicate lots of 3,000 fish/tank were fed either a gelatin–casein diet (Gel), a semimoist extruded diet (Biotrainer), or dehydrated, decapsulated brine shrimp (Artemia sp.) cysts (Decaps). Mean survival to 21 d was greater for fish consuming Biotrainer (12.3%) than for fish fed Decaps (1.6%) or Gel (0.5%). Fish consuming Decaps were longer at the end of the trial (P < 0.01) than either Biotrainer- or Gel-fed groups (18.2 mm versus 16.7 and 13.1 mm total length, respectively), but the proportion with inflated swim bladders was less (44% Decaps versus 83% Biotrainer and 94% Gel; P < 0.01). In experiment 2, Biotrainer and Decaps were fed to triplicate lots of 2,000 fish/tank. Mean total length at 28 d was greater (P < 0.01) for fish consuming Decaps (21.3 versus 17.3 mm), but survival (Decaps, 6.1 %; Biotrainer, 5.3%) and swim bladder inflation (Decaps, 57%, Biotrainer, 60%) did not differ between the two treatments. The percentage of fish with inflated swim bladders, which had been low in earlier trials, seemed to increase with the use of feeding rings; the rings restricted the area of surface film caused by the feeds. The Decaps and Biotrainer were both consumed well and supported adequate growth rates.

Congenital Hypoaldosteronism

Identical male twins suffering from congenital hypoaldosteronism due to a rare adrenal enzyme deficiency between corticosterone and aldosterone were followed-upfrom birth till their present age of 13 years. The symptoms of salt loss disappeared and normal growth rate resumed following treatment with DOCA and salt supplementation. Discontinuation of mineralocorticoid administration at the age of 7 years resulted during a 5-year period in a marked decline in their growth rate. Labororatory data revealed a persistent, albeit less pronounced, metabolic impairment. Mineralocorticoid administration was resumed and the twins entered normal puberty and increased their growth rate, emphasizing their need for continued mineralocorticoid administration to maintain adequate growth rate and development.

GROWTH STUDIES OF THREE CHLOROPHYLLOUS CALLUS PHENOTYPES OF GLYCINE MAX

The establishment of three chlorophyllous callus phenotypes, Glycine max (L.) Merrill, cultured on a modified Miller's medium is described. Experiments were designed to determine the hormonal requirement necessary to maintain an adequate callus growth rate that would allow for the phenotypical accumulation of chlorophyll in all phenotypes. Addition of α‐naphthaleneacetic acid and kinetin, both at 1 mg/liter, to the basal medium fulfilled this requirement. However, callus growth for these phenotypes required only an exogenous supply of cytokinin. All callus phenotypes, when maintained on 3% sucrose, were shown to possess similar growth curves; however, optimal growth rates of these cultured phenotypes occurred on different levels of exogenous sucrose (NG, 2%; LG, 1%; Y, 2%). Sucrose (filtered and autoclaved) and, in most cases, fructose (filtered), when employed as a carbon source in the basal medium, maintained adequate growth rates. Glucose (filtered) supported only minimal callus growth. These callus phenotypes, after two years in culture, showed a certain degree of cell type differentiation as indicated by the formation of isolated tracheoids and in some cases organized tracheoid development. The chromosome complement (2n = 40) was observed to be polyploid.

Growth Studies of Three Chlorophyllous Callus Phenotypes of Glycine max

The establishment of three chlorophyllous callus phenotypes, Glycine max (L.) Merrill, cultured on a modified Miller's medium is described. Experiments were designed to determine the hormonal requirement necessary to maintain an adequate callus growth rate that would allow for the phenotypical accumulation of chlorophyll in all phenotypes. Addition of α-naphthaleneacetic acid and kinetin, both at 1 mg/liter, to the basal medium fulfilled this requirement. However, callus growth for these phenotypes required only an exogenous supply of cytokinin. All callus phenotypes, when maintained on 3% sucrose, were shown to possess similar growth curves; however, optimal growth rates of these cultured phenotypes occurred on different levels of exogenous sucrose (NG, 2%; LG, 1%; Y, 2%). Sucrose (filtered and autoclaved) and, in most cases, fructose (filtered), when employed as a carbon source in the basal medium, maintained adequate growth rates. Glucose (filtered) supported only minimal callus growth. These callus phenotypes, after two years in culture, showed a certain degree of cell type differentiation as indicated by the formation of isolated tracheoids and in some cases organized tracheoid development. The chromosome complement (2n = 40) was observed to be polyploid.

Growth Rate and Nutrient Uptake of Two Cotton Cultivars Grown Under Irrigation1

AbstractThe production of high cotton yield is highly dependent on adequate growth rate and nutrient uptake about which relatively little information is available under semiarid conditions. Growth rate and N, P, K uptake of two cotton (Gossypium hirsutum L.) cultivars, ‘Acala 1517‐C’ and ‘Acala 4‐42,’ which differ in their response to K fertilizer, were investigated in an irrigated field (soil type ‐ Typic Rhodoxeralf) under favorable conditions conducive to high yields.The rate of dry matter production was slow until flowering and after the first bolls opened. Up to 72 days from emergence, 15% of the total dry matter was produced; from 112 days until picking, 10%; and during the 40‐day period from 72 to 112 days, 75%. Throughout this period the growth rate was nearly linear, 250 kg/ ha/day.Total dry matter was 12,200 to 13,480 kg/ha. Its distribution in mature plants was 26% in the leaves, 24% in stems, 16% in burs, 21% in seeds, and 13% in lint. The lint yield was 1,700 kg/ha. Total uptake of N, P, and K was 230, 45, and 174 kg/ha.The total uptake of N and P followed that of dry matter production, whereas K was absorbed more rapidly, reaching a maximum at 112 days from emergence and then decreasing. The removal of nutrients from the field by seed and lint was 98 to 109 kg N/ha, 19 to 21 kg P/ha, and 43 to 47 kg K/ha.Toward the end of growing season Acala 1517‐C suffered more than Acala 4‐42 from K deficiency in soils with a low supply of available K. The factors which may be responsible for this in Acala 1517‐C are earlier development, greater uptake of K during early growth, the larger uptake of K by relatively more developed reproductive parts, and the relatively smaller root system.The rates of growth and uptake in the present experiment were greater than those reported in the literature. Also, Acala 1517‐C and Acala 4‐42 differed in their nutrient uptake, especially of potassium.

THREONINE AS THE SECOND LIMITING AMINO ACID IN PEACE RIVER BARLEY FOR GROWING–FINISHING PIGS AND GROWING RATS

Barley–lysine diets (0.75% total lysine, 0.37% threonine) with or without additional threonine and methionine were compared with a barley and 15.6% soybean meal control diet in a growth trial with 108 pigs and a metabolism trial with six collection periods per diet. Addition of threonine to the barley–lysine diet improved daily gain, feed efficiency and carcass quality, with the growth results obtained with the 0.10% threonine addition equalling those of the barley–soybean meal diet, except for backfat thickness, which was lower on the soybean meal diet. Nitrogen retention, however, increased up to the maximum level (0.15%) of threonine inclusion, when retention equalled that of the control diet. Addition of 0.10% methionine to the barley diet containing added lysine and threonine resulted in no responses. Growth and balance trials with weanling rats in general confirmed results obtained with the pigs. No additional beneficial effects were obtained when lysine levels were increased from 0.75 to0.90%, even when supplemented with additional threonine. However, in order to obtain results similar to those obtained on the barley–soybean meal diet, threonine additions to the barley had to be increased to 0.20% (0.57% total threonine) with the addition of a mixture containing other essential amino acids. Replacement of the essential amino acid mixture with glycine on an equal nitrogen basis did not produce adequate nitrogen retention or growth rate.

Effect of dietary protein restriction on the levels of free L-hydroxyproline in the plasma of the male domestic fowl.

Synopsis Two experiments were performed, in the first plasma‐free L‐hydroxyproline was measured in young male chickens given one of three diets containing differing quantities of protein. In the second, plasma‐free L‐hydroxyproline was determined in young males subjected to a short period of protein deprivation. It was found that in birds fed adequate protein, plasma‐free L‐hydroxyproline and growth rate were related but that in those on a restricted protein intake the values tended to be low relative to age during the early stages of the experiment. Birds deprived of protein showed reduced L‐hydroxyproline concentrations in the plasma, but when returned to a normal diet the values increased progressively, slightly exceeding those in the corresponding control birds.

The Growth of Indian Agriculture: A Regional Analysis

providing about 50 percent of the gross national product and nearly 70 percent of the employment, an adequate agricultural growth rate is essential for sustained economic progress. The growth rate of agricultural output has a considerable influence on the overall growth rate of the economy and on the productivity of a large part of the work force. Moreover, a rapid increase in agricultural output is essential to meet the increasing demand for food and other agricultural products, which results from the rapid population growth (currently estimated at 2.5 percent per year) and from the rise in per capita consumption. This is particularly important, since India had a foodsupply deficit, even at extremely low levels of per capita consumption, at the beginning of the economic-development process. The importance of adequate agricultural growth to the success of India's efforts at planned economic development was demonstrated dramatically, if painfully, during the years 1965-1967, when the country experienced widespread drought and a steep drop in agricultural output. Foodgrain production, for instance, declined from 89 million metric tons in 1964-1965 to 72 million tons in 1965-1966 and rose only slightly, to 78 million tons, in 1966-1967. The fall in production led to scarcity and local famines, and large imports of 9 to 10 million tons of foodgrains annually were necessary. But agricultural production in 1967-1968 and 1968-1969 has been high again, with foodgrain production in both years estimated at around 95 million tons, mainly as a result of more favorable monsoons. But the drought experience has led to a reappraisal of development objectives and to the initiation in 1966 of an agricultural development program that concentrates on new high-yielding seed varieties, chemical fertilizers, pesticides, and efficient water management in selected areas to increase output rapidly.' India's three Five Year Plans included large outlays for increasing agricultural production: expenditures amounted to 36,330 million rupees, or 23.9