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The velopharyngeal (VP) mechanism is a muscular valve that controls the amount of nasal acoustic energy and oral pressure for speech production through opening and closing, respectively. Directly posterior to [...], Purpose: Limited quantitative data exist regarding growth of the velopharynx within the first 2 years of life. The purpose of this study was to (a) quantify changes in velopharyngeal structures due to growth during the first 2 years of life, (b) examine the impact of sex and race within this age range, and (c) provide normative measures for comparison to individuals with cleft palate. Method/Description: A retrospective chart review was completed of all patients up to 24 months of age that underwent magnetic resonance imaging of the head for medical necessity within the past 18 months using a three-dimensional fluid-attenuated inversion recovery sequence. Measurements of the velopharynx were obtained from 200 scans consistent with previous literature. Participants were divided into five groups based on corrected age for comparison. Variables of interest included adenoid depth, angle of origin, effective velopharyngeal ratio, effective velar length, levator veli palatini length, origin-origin distance, pharyngeal depth, sagittal angle, velopharyngeal ratio, velar insertion distance, velar length, and velar thickness. Results: Velopharyngeal dimensions were significantly different among corrected age groups after controlling for sex and race. Regarding age, analyses revealed significant differences in all variables of interest except effective velopharyngeal ratio. Regarding sex, significant differences were observed for angle of origin, effective velopharyngeal ratio, effective velar length, levator veli palatini muscle length, and velar insertion distance. Regarding race, a significant difference was only observed for angle of origin. Conclusions: Results of this study demonstrate growth of velopharyngeal anatomy in normative infants with race and sex effects apparent in children up to 24 months of age. Variable growth trends were observed among different velopharyngeal measures.

Author(s): José Villar [sup.1] [sup.2] , Robert B. Gunier [sup.3] , Chrystelle O. O. Tshivuila-Matala [sup.1] [sup.4] [sup.5] , Stephen A. Rauch [sup.3] , Francois Nosten [sup.6] [sup.7] , Roseline [...], Many observational studies and some randomized trials demonstrate how fetal growth can be influenced by environmental insults (for example, maternal infections).sup.1 and preventive interventions (for example, multiple-micronutrient supplementation).sup.2 that can have a long-lasting effect on health, growth, neurodevelopment and even educational attainment and income in adulthood.sup.3. In a cohort of pregnant women (n = 3,598), followed-up between 2012 and 2019 at six sites worldwide.sup.4, we studied the associations between ultrasound-derived fetal cranial growth trajectories, measured longitudinally from This study of a cohort of over 3,500 pregnant women in six different populations worldwide identifies specific fetal cranial growth trajectories, measured by serial ultrasound scans early in gestation, that are related to postnatal growth and neurodevelopment up to the key milestone age of 2 years.

Organisms with a complex life cycle are characterized by a life-history shift through metamorphosis and include organisms such as insects and amphibians. They must optimize their use of resources and behaviour across different life stages to maximize their fitness. An interesting question with regard to such life-history shifts is whether growth in the juvenile stage can be compensated for in the adult stage. Here we ask whether emerald damselflies (Lestes sponsa (Hansemann, 1823)) are able to compensate for depressed growth during the juvenile aquatic stage in their terrestrial adult stage. Lestes sponsa emerge at a fixed adult body size, but feed during the adult stage and are thus able to gain mass as adults. We performed a mark-recapture study to answer whether individuals that emerge from metamorphosis with a low mass are able to compensate by subsequent mass gain during the adult stage. Results showed that compensatory mass gain occurred in the adult stage such that small individuals gained more mass than large individuals. We also found that females gained more mass than males. However, individuals that emerged at a low mass still had lower mass as mature adults than individuals that emerged at a high mass, suggesting that compensation was not complete. This suggests that larval ecology and adult fitness are tightly linked and future research should focus more on elucidating the nature of this relationship. Key words: compensatory growth, complex life cycle, habitat shift, fitness, optimal body size and mass, emerald damselfly, Lestes sponsa. Les organismes presentant des cycles biologiques complexes sont caracterises par un changement biologique opere par la metamorphose et comprennent des organismes comme les insectes et les amphibiens. Ces organismes doivent optimiser leur utilisation des ressources et leur comportement durant differentes etapes du cycle biologique afin de maximiser leur aptitude. En ce qui concerne de tels changements biologiques, il est interessant de savoir si la croissance au stade juvenile peut etre compensee au stade adulte. Nous verifions si une croissance reduite durant le stade juvenile aquatique chez le leste fiance (Lestes sponsa (Hansemann, 1823)) peut etre compensee durant le stade adulte terrestre. Lestes sponsa emergent a une taille du corps adulte fixe, mais se nourrissent durant le stade adulte et peuvent donc accroitre leur masse durant ce stade. Nous avons realise une etude de marquage-recapture afin de determiner si les individus qui emergent de la metamorphose avec une masse plus faible sont en mesure de compenser cette faible masse par un gain de masse subsequent durant le stade adulte. Les resultats montrent qu'un gain de masse compensateur se produit au stade adulte, de sorte que les petits individus gagnent plus de masse que les plus gros individus. Nous avons egalement constate que le gain de masse etait plus grand chez les femelles que chez les males. Cependant, les individus qui emergeaient a faible masse presentaient toujours une masse plus faible comme adultes matures que les individus plus massiques au moment de l'emergence, donnant a penser qu'il n'y avait pas compensation complete. Ces resultats portent a croire que l'ecologie des larves et l'aptitude des adultes sont intimement reliees, et des travaux futurs devraient tenter d'elucider la nature de ce lien. [Traduit par la Redaction] Mots-cles : croissance compensatrice, cycle biologique complexe, changement d'habitat, aptitude, taille et masse corporelles optimales, leste fiance, Lestes sponsa., Introduction Many organisms have a complex life cycle that involves an abrupt change in an individual's morphology, physiology, and behaviour (Semlitsch et al. 1988; Rowe and Ludwig 1991). Examples of [...]

Introduction The relationship between chronic kidney disease (CKD), reduced dietary intake and growth has been recognised for many years. In a seminal paper in 1974, Betts and Magrath studied the [...], Despite continuing improvements in our understanding of the causes of poor growth in chronic kidney disease, many unanswered questions remain: why do some patients maintain a good appetite whereas others have profound anorexia at a similar level of renal function? Why do some, but not all, patients respond to increased nutritional intake? Is feed delivery by gastrostomy superior to oral and nasogastric routes? Do children who are no longer in the 'infancy' stage of growth benefit from enteral feeding? Do patients with protein energy wasting benefit from increased nutritional input? How do we prevent obesity, which is becoming so prevalent in the developed world? This review will address these issues. Keywords Growth * Gastrostomy * Diet * Dialysis * Height * Obesity * Chronic kidney disease * Progression

Latitudinal growth compensation (i.e., countergradient growth) is increasingly suspected to be pervasive across diverse taxa. However, a major challenge limiting wider exploration of this topic lies in the difficulty of quantifying these relationships. Common garden experiments, and ideally genetics, remain the only true methods for understanding the genetic basis for compensatory growth. However, previous research suggests that comparative life-history data might produce concomitant, albeit nonconfirmatory, results on countergradient growth variations. However, there have been no evaluations of the precision of such estimates against those that are experimentally derived. I examined countergradient growth variations using comparative size-at-age data for striped bass (Morone saxatilis), a species for which experiments have already quantified countergradient growth patterns, and compared results derived from both techniques. The slope of the growth-latitude relationship for striped bass in eastern North America as measured with comparative data was virtually identical to that produced from experiments. Furthermore, comparative estimates of countergradient growth variations developed using a variety of metrics produced highly concordant results with one another. Comparative life-history data are not a replacement for experiments, but do provide valuable information on countergradient growth variations, especially for species and hypotheses not amenable to experimentation. La compensation latitudinale de la croissance (c.-a-d. croissance contre-gradient) est de plus en plus soupconnee d'etre largement repandue dans bon nombre de taxons. Un des defis que presente l'exploration approfondie de ce phenomene repose toutefois dans la difficulte de quantifier ces liens. Des experiences dans des conditions identiques et, idealement, la genetique demeurent les seules methodes permettant vraiment de mieux comprendre les bases genetiques de la croissance compensatoire. Des travaux anterieurs suggerent toutefois que des donnees comparatives sur le cycle biologique peuvent produire des resultats concomitants, bien que non confirmatoires, relativement aux variations de croissance contregradient. Aucune evaluation de la precision de telles estimations a la lumiere d'estimations experimentales n'a cependant ete realisee. J'ai examine les variations de croissance contre-gradient en utilisant des donnees comparatives de taille selon l'age pour le bar raye (Morone saxatilis), une espece dont des experiences ont deja quantifie des patrons de croissance contre-gradient, et j' ai compare les resultats issus des deux techniques. La pente de la relation croissance-latitude pour le bar raye dans l' est de l'Amerique du Nord mesuree a partir des donnees comparatives etait essentiellement identique a la pente decoulant de donnees experimentales. En outre, les estimations comparatives des variations de croissance contre-gradient obtenues a partir de divers parametres ont donne des resultats hautement concordants les uns avec les autres. Les donnees comparatives sur le cycle biologique ne peuvent remplacer les experiences, mais fournissent neanmoins des renseignements utiles sur les variations de croissance contre-gradient, en particulier pour les especes et hypotheses ne se pretant pas a l'experimentation. [Traduit par la Redaction], Countergradient growth variations are increasingly recognized as widespread across diverse fish species (Conover and Present 1990; Venturelli et al. 2010; Rypel 2011). The countergradient growth pattern is ostensibly a genetically [...]

ABSTRACT Fifteen-day pediveliger larvae of Anadara grandis (shell length, 230 ± 20 µm (mean ± SD, n = 20) were cultivated up to the juvenile stage by testing 2 densities: [...]

ABSTRACT Reproductive biology, size at sexual maturity, and growth of the deep-water shrimp Solenocera melantho were studied in the East China Sea. The spawning season continues from July to November, [...]

ABSTRACT An Eulerian approach was applied through a daily data set (n = 51) on mantle length frequencies of jumbo squid Dosidicus gigas derived from a small jigging fleet (5 [...]

ABSTRACT In this study, we evaluated the growth of adults and juveniles of the endangered noble pen shell Pinna nobilis, calculated the growth rates of newly recruited juveniles, and described [...]

ABSTRACT We describe the growth of the Cortes geoduck Panopea globosa (Dall 1898) in the Central Gulf of California using a multimodel approach. Geoducks were collected from November 2008 to [...]

ABSTRACT Spat of 2 pectinid species of commercial interest were grown in suspension to study the growth of the gonad, digestive gland, and adductor muscle at 3 different depths (2.5 [...]

Batch culture experiments were performed to investigate potential effects of nutrient starvation on the allelochemical potency of the toxic dinoflagellate Alexandrium tamarense. Triplicate cultures with reduced nitrate (-N) or phosphate (-P) seed were compared to nutrient-replete (+N+P) cultures. Total depletion of the dissolved inorganic limiting nutrient, reduced cell quotas, changed mass ratios of C/N/P and reduced cell yield clearly indicate that treatment cultures at stationary phase were starved by either N or P, whereas growth cessation of +N+P cultures was probably due to carbon limitation and/or a direct effect of high pH. Pulsed addition of the limiting nutrient allowed -N and -P cultures to resume growth. Lytic activity of A. tamarense as quantified by a Rhodomonas bioassay was generally high ([EC.sub.50] around 100 cells [mL.sup.-1]) and was only slightly modulated by growth phase and/or nutrient starvation. Lytic activity per cell increased with time in both +N+P and -P cultures but not -N cultures. P-starved stationary-phase cells were slightly more lytic than +N+P cultures, but this difference may be due to increased cell size and/or accumulation of extracellular compounds. In conclusion, only slight changes but no general and major increase in lytic activity in response to nutrient starvation was observed., Introduction Temporal and spatial changes of biomass and species composition in marine plankton have traditionally been thought to be mainly regulated by resource availability and abiotic factors. However, there is [...]

Body size has great influence on feeding, reproduction, and ecological importance. This study measures growth, reproduction, and feeding for several northeastern Pacific intertidal invertebrates that have indeterminate growth. In all species studied, linear size (length, diameter) showed asymptotic growth fit by the von Bertalanffy growth function, supporting the notion that less energy is allocated to growth with age because of increased reproduction. However, these same species displayed a continuous, roughly linear increase in volume with age. Both reproductive output and food intake were shown to scale proportionally with volume. This indicates that some species with indeterminate growth do not reduce energy allocation to growth with age but instead display continuous volumetric growth that facilitates increases in feeding rate and reproductive output with age and size. A simple allometric model is proposed to describe constant volumetric growth rates and linear increases in reproduction with age., Introduction The size of an organism has a large impact on its ecology and reproductive output. Regardless of how size is defined, it has a strong elect on feeding, growth [...]

Abstract--We propose an extended form of the von Bertalanffy growth function (VBGF), where the allocation of surplus energy to reproduction is considered. Any function can be used in our model [...]

Disparities in longitudinal growth within a species can be partly explained by endocrinological differences. We hypothesized that regulatory networks acting locally in the growth plate may also be important. We tested this hypothesis by evaluating the IGF/IGFBP expression, the vitamin D pathway, and the PTHrP-Indian hedgehog (IHH) feedback loop in rib growth plates from 10- and 21-wk-old small- (Miniature Poodles, MP) and large-breed dogs (Great Danes, GD) using immunohistochemistry and quantitative (q)PCR. The rib growth plates of GD were 1.7 times thicker compared with those of MP, with larger proliferative (in absolute terms) and larger hypertrophic (in absolute and relative terms) zones. IGF/IGFBP gene expression profiling of the growth plates revealed decreased gene expression of igfbp2, -4, and -6 and an unaltered expression of igf-I and igf-II and their respective receptors in GD vs. MP. Immunohistochemistry and qPCR findings showed that the vitamin D pathway was more active in GD than in MP. Staining for 1[alpha]- and 24-hydroxylase was more abundant and intense in GD and the gene expressions of 1[alpha]-hydroxylase and the vitamin D receptor-driven 24-hydroxylase were six- and eightfold higher in GD vs. MP, respectively. Consistent with the immunohistochemistry findings, the expression of mRNA for components of the parathyroid hormone-related peptide (PTHrP)-IHH loop was different in GD compared with MP, with there being a relative threefold downregulation of Pthrp and a tenfold upregulation of Ihh in GD vs MP. These differences suggest that the effects of IHH in the regulation of chondrocyte proliferation and hypertrophy, both independently of PTHrP, can become more dominant during rapid growth rates. In conclusion, our data suggest that, in addition to modest endocrine differences, more pronounced changes in the expression of locally acting regulatory networks, such as the IGF system, vitamin D pathway, and PTHrP-IHH feedback loop are important contributors to within-species disparities in growth rates. canine; growth plate; vitamin D; Indian hedgehog; parathyroid hormone-related peptide; insulin-like growth factor doi: 10.1152/ajpendo.00170.2010.

When trade-offs involving predation and mortality are perturbed by human activities, behaviour and life histories are expected to change, with consequences for natural mortality rates. We present a general life history model for fish in which three common relationships link natural mortality to life history traits and behaviour. First, survival increases with body size. Second, survival declines with growth rate due to risks involved with resource acquisition and allocation. Third, fish that invest heavily in reproduction suffer from decreased survival due to costly reproductive behaviour or morphology that makes escapes from predators less successful. The model predicts increased natural mortality rate as an adaptive response to harvesting. This extends previous models that have shown that harvesting may cause smaller body size, higher growth rates, and higher investment in reproduction. The predicted increase in natural mortality is roughly half the fishing mortality over a wide range of harvest levels and parameter combinations such that fishing two fish kills three after evolutionary adaptations have taken place. Resume: Lorsque les compromis entre la predation et la mortalite sont perturbes par les activites humaines, on s'attend a ce que les comportements et les cycles biologiques changent, ce qui affecte les taux de mortalite naturelle. Nous presentons un modele general de cycle biologique dans lequel trois relations courantes relient la mortalite naturelle aux traits du cycle biologique et au comportement. Dabord, la survie augmente en fonction de la taille corporelle. Ensuite, la survie diminue en fonction du taux de croissance a cause des risques relies a l'acquisition et l'allocation des ressources. Enfin, les poissons qui investissent beaucoup dans la reproduction ont une survie reduite a cause des couts associes aux comportements reproducteurs ou a la morphologie qui reduisent le succes de l'evitement des predateurs. Le modele predit un taux de mortalite naturelle accru comme reaction adaptative a la recolte. Cela elargit les modeles anterieurs qui ont montre que la recolte peut produire des tailles corporelles reduites, des taux de croissance plus eleves et un investissement accru dans la reproduction. L'accroissement predit de la mortalite naturelle correspond en gros a la moitie de la mortalite due a la peche sur un large eventail d'intensites de recoltes et de combinaisons de parametres, de telle sorte que la peche de deux poissons en elimine trois une fois que les adaptations evolutives ont eu lieu. [Traduit par la Redaction], Introduction Current fishing levels have been suggested to induce evolutionary changes in fish stocks on decadal time scales (Law and Grey 1989; Rijnsdorp 1993; J∅rgensen et al. 2007). A reduction [...]

Growing degree-days (GDD, °C*days) are an index of ambient thermal energy that relates directly to an ectotherm's cumulative metabolism but is rarely used to describe growth and development in fish. We applied GDD to length and maturity data from 416 populations of walleye (Sander vitreus) from Ontario and Quebec, Canada (mean annual GDD = 1200 to 2300 °C*days). On average, males matured after they had experienced 6900 °C*days and reached 350 mm total length (L) (n = 77 populations), and females matured after 10 000 °C*days and at 450 mm L (n = 70). Across 143 populations, GDD accounted for up to 96% of the variation in the length of immature walleye but also revealed a twofold difference in growth rate that was indicative of variation in food availability. When applied to data from eight populations in which walleye abundances have changed dramatically over time, GDD revealed a 1.3-fold increase in immature growth rate when abundance was low compared with when it was high. Our results both demonstrate the explanatory power of GDD with respect to fish growth and maturity and inform the development of regional management strategies for walleye. Resume: Bien que les degres-jours de croissance (GDD, °C*jours) soient un indice d' energie thermale directement relie au cumulatif metabolisme chez les ectothermes, cet indicateur a rarement ete conside re pour decrire la croissance et le developpement des poissons. Nous avons utilise l'indice GDD dans l'analyse de donnees de taille et de maturite provenant de 416 populations de dores jaunes (Sander vitreus) de l'Ontario et du Quebec, Canada (moyenne annuelle GDD = 1200 a 2300 °C*jours). En moyenne, les males ont atteint la maturite a 6900 °C*jours, correspondant a une longueur totale de 350 mm (n = 77 populations), et les femelles a 10 000 °C*jours, correspondant a une longueur totale de 450 mm (n = 70). Dans une analyse comprenant 143 populations, l'indicateur GDD a permis d'expliquer jusqu'a 96 % de la variabilite dans la taille des individus immatures, en plus de reveler que la variabilite dans l'abondance des proies peut conduire a des differences du taux de croissance allant jusqu'au double. En utilisant les donnees de huit populations au sein desquelles une grande variation de l'abondance des dores avait vraisemblablement cause de grands changements dans l'abondance des proies, l'indice GDD a montre que le taux de croissance des individus immatures beneficiant d'une forte disponibilite de proies etait de 1,3 fois superieur a celui d'individus subissant une faible disponibilite de proies. Nos resultats demontrent le pouvoir de l'indicateur GDD pour expliquer la variabilite dans la croissance et la maturite et seront utiles au developpement de strategies regionales de gestion des populations de dores jaunes., Introduction Fish growth and development are primarily functions of food and temperature (Fry 1971; Kitchell et al. 1977; Paloheimo and Dickie 1966). Recently, Neuheimer and Taggart (2007) showed that growing [...]

Traditional methods for modeling growth of free-ranging fish are often limited by missing recapture observations that prevent individual growth estimates for a given time interval. Our purpose is to present a method for modeling growth rates of juvenile steelhead (Oncorhynchus mykiss) that addresses this limitation. Age-1 juvenile steelhead were individually marked with passive integrated transponder (PIT) tags, released in a Michigan, USA, watershed, and sampled monthly (May-November) with barge electrofishing. Individual growth was modeled using daily water temperature and observed fish sizes as inputs and by determining the proportion of maximum consumption parameter (P) for the bioenergetics equation that provided a minimum residual squared error. Results demonstrate that individual steelhead growth can be accurately modeled using water temperature and a temporally specific P shared by all individuals. Advantages of using this method to model fish growth include the ability to bridge data gaps where observations are lacking in individual length histories, rigorously test for differences in P across time periods, and estimate variability of P among fish within a given stream reach. Resume: Les methodes traditionnelles de modelisation de la croissance des poissons libres en nature sont souvent restreintes par le manque dobservations de recaptures qui empeche lestimation des croissances individuelles pendant un certain intervalle de temps. Notre objectif est de presenter une methode de modelisation des taux de croissance de jeunes truites arc-en-ciel anadromes (Oncorhynchus mykiss) qui resoud ce probleme. Nous avons marque individuellement des jeunes truites arc-en-ciel anadromes dege 1 dune etiquette PIT (transpondeur integre passif), les avons liberees dans un bassin versant du Michigan, E .-U., et les avons echantillonnes chaque mois (mai-novembre) par peche electrique sur barge. Nous avons modelise la croissance individuelle en utilisant les temperatures journalieres de l'eau et les tailles de poissons observees comme donnees d'entree et en determinant la proportion du parametre de consommation maximale (P) de l'equation bioenergetique qui produit l'erreur au carre residuelle minimale. Nos resultats demontrent quil est possible de modeliser avec precision la croissance individuelle des truites arc-en-ciel anadromes a partir des temperatures de l'eau et d'une valeur de P specifique au temps et commune a tous les individus. Les avantages d'utiliser cette methode pour la modelisation de la croissance des poissons incluent la capacite de combler des lacunes dans les donnees lorsqu'il manque des informations sur l'evolution des croissances individuelles, de tester rigoureusement les differences de P entre les diverses periodes et d'estimer la variabilite de P entre les poissons d'une meme section de cours d'eau. [Traduit par la Redaction], Introduction Bioenergetics models are a popular tool for providing insight into the growth dynamics of fishes. These models have numerous applications in fisheries science, with two common themes being (i) [...]

The Hippo signaling pathway regulates organ size and tissue homeostasis from Drosophila to mammals. At the core of the Hippo pathway is a kinase cascade extending from the Hippo (Hpo) tumor suppressor to the Yorkie (Yki) oncoprotein. The Hippo kinase cascade, in turn, is regulated by apical membrane-associated proteins such as the FERM domain proteins Merlin and Expanded (Ex), and the WW- and C2-domain protein Kibra. How these apical proteins are themselves regulated remains poorly understood. Here, we identify the transmembrane protein Crumbs (Crb), a determinant of epithelial apical-basal polarity in Drosophila embryos, as an upstream component of the Hippo pathway in imaginal disk growth control. Loss of Crb leads to tissue overgrowth and target gene expression characteristic of defective Hippo signaling. Crb directly binds to Ex through its juxtamembrane FERM-binding motif (FBM). Loss of Crb or mutation of its FBM leads to mislocalization of Ex to basolateral domain of imaginal disk epithelial cells. These results shed light on the mechanism of Ex regulation and provide a molecular link between apical-basal polarity and tissue growth. Furthermore, our studies implicate Crb as a putative cell surface receptor for Hippo signaling by uncovering a transmembrane protein that directly binds to an apical component of the Hippo pathway. apical-basal polarity | development | Drosophila | organ size | signal transduction doi/ 10.1073/pnas.1004279107

Many research studies have focused on the interactions among larval anurans, but relatively little is known about competitive or predatory interactions among anurans following metamorphosis. The purpose of our study was to examine the effects of post-metamorphic green frogs (Rana damitans) on post-metamorphic American toads (Bufo americanus) in the terrestrial environment as a model for understanding how interspecific differences in size at metamorphosis may influence terrestrial interactions. We examined if caged, uncaged or no green frogs affected survival, growth and hiding behavior of recently metamorphosed American toads in a replicated laboratory experiment. Green frogs did not appear to prey upon small American toads. However, by the end of the experiment American toad survival was lowest in treatments with uncaged green frogs; this result suggests that green frogs may outcompete American toads for food, but such impacts in nature may be limited or may have selected for spatial segregation in the terrestrial environment. Green frogs also increased hiding activity of toads at some times, which may in part explain the trend of reduced mass gained when toads were reared with green frogs. This study represents one of the first to examine interspecific interactions among anurans with complex life cycles in the terrestrial environment., INTRODUCTION Amphibians with complex life cycles have different strategies to deal with biotic and abiotic pressures in aquatic and terrestrial environments (Wilbur and Collins, 1973; Werner, 1986). Alterations in length [...]

Raymond Pearl, the founder of Human Biology, was concerned throughout his career with the 'proper measure of man' (Sokal 2004), probably his main legacy to anthropological sciences. Because the Proceedings [...], Walker et al. ["Growth rates and life histories in twenty-two smallscale societies," Am. J. Hum. Biol. 18:295-311 (2006)] used life history theory to develop an innovative explanation for human diversity in stature. Short stature could have been selected for in some human populations as a result of the advantage of an earlier growth cessation and earlier reproduction in a context of high mortality. Migliano et al. ["Life history trade-offs explain the evolution of human pygmies," Proc. Natl. Acad. Sci. USA 104:20,216-20,219 (2007)] recently published an important article that tested this hypothesis to explain short stature in human pygmy populations. However innovative this work may be, we believe that some of the data and results presented are controversial if not questionable. As problematic points we note (1) the use of an arbitrary threshold of height (155 cm) to categorize populations into pygmies and nonpygmies; (2) the use of demographic data from Philippine pygmy groups that have experienced dramatic cultural and environmental changes in the last 20 years, and (3) the use of demographic data concerning African pygmy groups because good systematic data on these groups are not available. Finally, we report here mathematical errors and loopholes in the optimization model developed by Migliano and colleagues. In this paper we suggest alternative trade-offs that can be used to explain Migliano's results on more reliable bases. KEY WORDS: PYGMIES, HEIGHT, LIFE HISTORY, DEMOGRAPHY, MORTALITY, FERTILITY.

Problem statement: Literature data on the effect of dietary fat on growth performance in rabbits are inconclusive. For commercial rabbit production it is relevant to know to what extent dietary fat level and type can be manipulated. In the present study serum cholesterol was also analyzed because its relation to the amount and type of dietary fat was not known for rabbits. Approach: Young growing rabbits were fed diets containing one of four different levels (5.2-41.8 energy %) of either coconut fat or corn oil. Fat was added to the diets at the expense of an isoenergetic amount of corn starch and dextrose in a 1:1 ratio. The diets were in pelleted form and supplied ad libitum. Results: Increasing fat intakes in the form of either coconut fat or corn oil enhanced weight gain and improved feed efficiency. The effect of coconut fat was maximal at 20.9 energy % (9.9%, w/w) and the greatest effect of corn oil was seen at an inclusion level of 41.8 energy % (20.2%, w/w). As would be expected, replacement of dietary corn oil by coconut fat significantly decreased serum cholesterol concentrations. The cholesterol-lowering effect of corn oil versus coconut fat increased markedly with higher dietary inclusion levels of fat. Conclusion: The addition of fat to the diet improved growth performance. It is suggested to find out whether the present observations can be applied in the formulation of diets for fryer rabbits. The new observation for rabbits is that the hypocholesterolemic response to corn oil increased with higher intake levels. Key words: Rabbits, coconut fat, corn oil, saturated fatty acids, polyunsaturated fatty acids, growth performance, cholesterol, INTRODUCTION The requirement of dietary fat by rabbits has been set at 2% (w/w) of a diet containing 90% (w/w) of dry matter (National Research Council, 1977). Since plant foodstuffs [...]

Four experiments were conducted to determine the effects of standardized ileal digestible (SID) Lys:calorie (Lys:Mcal) ratio on growth performance of 10-to 20-kg pigs of 2 different genotypes. Experiment 1 (360 pigs, average BW = 10.2 kg; source 1) and Exp. 2 (351 pigs; average BW = 9.3 kg; source 2), were both organized as a combination of 2 simultaneous experiments with the first set of diets consisting of 5 treatments with increasing SID Lys and the second set of diets consisting of 5 treatments with increasing energy density (Exp. 1: 9.9, 10.7, 11.5, 12.2, and 13.0 g/kg of Lys and 2.95, 3.09, 3.24, 3.38, and 3.52 Mcal/ kg of ME, respectively; Exp. 2: 11.1, 11.9, 12.6, 13.4, and 14.2 g/kg and 2.95, 3.10, 3.25, 3.40, and 3.55 Mcal of ME/kg, respectively). In Exp. 1, increasing dietary SID Lys increased (linear, P < 0.01) ADG and G:F, and increasing dietary ME increased (quadratic, P < 0.05) G:F. In Exp. 1 the optimal Lys:Mcal ratio was estimated to be at least 4.1 g of Lys/Mcal of ME based on G:F. In Exp. 2, increasing dietary SID Lys increased (linear, P < 0.01) ADG and G:F. Increasing dietary ME increased (linear, P < 0.01) G:F. Because of the linear responses in this experiment, optimal Lys:Mcal ratio was at least 4.0 g of Lys/Mcal of ME. In Exp. 3 (350 pigs; average BW = 9.4 kg; source 1) and Exp. 4 (350 pigs; average BW = 7.5 kg; source 2), Lys:Mcal ratios in Exp. 1 and 2 were compared by titrating Lys at 2 energy levels. Pigs were fed diets with 2.95 or 3.29 Mcal/kg of ME with SID Lys:Mcal ratios of 3.1 to 4.1 g/Mcal of ME (Exp. 3) and 3.5 to 4.5 g/Mcal of ME (Exp. 4). In Exp. 3, there was an ME x Lys:Mcal ratio interaction (P < 0.03) for ADG. The greatest ADG was a Lys:Mcal ratio of 3.60 for pigs fed low ME and a ratio of 3.35 for pigs fed high ME. Gain:feed ratio increased with increased (P < 0.01) ME concentration and as Lys:Mcal ratio increased (quadratic, P < 0.01); the best G:F was observed at 3.67 g of Lys/Mcal of ME. In Exp. 4, there was a tendency for ME x Lys:Mcal ratio interaction (P < 0.08) for G:F. The greatest G:F was achieved with a Lys: Mcal ratio of at least 4.50 for pigs fed low ME and a ratio of 4.29 for pigs fed high ME. Results (i.e., lack of ADG response to high energy density) suggest pigs reared in this environment were not in energy dependent growth phases. These pigs needed approximately 11 g/d of SID Lys (19 g of Lys/kg of gain) to optimize ADG and G:F. Based on these results, optimal Lys:Mcal ratio may differ depending on daily caloric intake of the pig. Key words: energy, growth, lysine, nursery pig, swine doi: 10.2527/jas.2008-1204

Abstract--The dusky rockfish (Sebastes variabilis) has recently been resurrected as a distinct species in the genus Sebastes. Reproductive biology and growth were examined for this redescribed species in the central [...]

A set of analyses using a multiple-trait model (model 1) and dynamic models for the evaluation of beef cattle growth is presented. All models contained additive direct and maternal environmental effects, as well as contemporary groups as nuisance parameters. The predictive ability of models at different parts of the growth trajectory was compared. Body weight records of 6,856 Nelore animals taken at 6 different ages (birth to 540 d) were used. Different models embedding a Kalman filter (KF) into a mixed model representation were fitted. Model 2 assumed that additive, maternal, and residual effects changed over time according to a linear autoregressive process. Model 3 was similar to model 2, but all regression coefficients were set to 1. In model 4, KF was applied only to direct genetic and maternal environmental effects. A leave-one-out cross-validation check was used to assess the predictive ability of models. Estimates of additive variance were similar in the analysis with models 1, 3, and 4 for all ages. Posterior means of maternal components increased slightly after birth and decreased after 135 d of age. Posterior means of additive rates of change were close to 1 at almost all time points, irrespective of the model. The posterior means of residual rates of change, which varied from 0.096 to 0.529, did not support the restrictions that regression coefficients were equal to 1 imposed by model 3. Estimates of additive and maternal correlations obtained with dynamic models were larger than those from a multivariate model. Model 3 produced different phenotypic correlations. Models 2 and 4 had better predictive ability than the multivariate specification. Model 3 predicted the data very poorly, and errors increased markedly with age. The KF can be a useful tool for structuring (co)variance matrices without reducing dimensionality. This model provided accurate predictions and plausible estimates of (co)variance components. Moreover, KF is a flexible specification, because a multivariate structure can be used for some random effects, whereas a dynamic feature can be incorporated for others. Key words: beef cattle, cross-validation, growth, Kalman filter, longitudinal data, predictive ability doi: 10.2527/jas.2008-1515

Long-term pulse chase experiments previously identified a sizable population of BrdU-retaining cells within the renal papilla. The origin of these cells has been unclear, and in this work we test the hypothesis that they become quiescent early during the course of kidney development and organ growth. Indeed, we find that BrdU-retaining cells of the papilla can be labeled only by pulsing with BrdU from embryonic (E) day 11.25 to postnatal (P) day 7, the approximate period of kidney development in the mouse. BrdU signal in the cortex and outer medulla is rapidly diluted by cellular proliferation during embryonic development and juvenile growth, whereas cells within the papilla differentiate and exit the cell cycle during organogenesis. Indeed, by E17.5, little or no active proliferation can be seen in the distal papilla, indicating maturation of this structure in a distal-to-proximal manner during organogenesis. We conclude that BrdU-retaining cells of the papilla represent a population of cells that quiesce during embryonic development and localize within a region of the kidney that matures early. We therefore propose that selective papillary retention of BrdU arises through a combination of regionalized slowing of, and exit from, the cell cycle within the papilla during the period of ongoing kidney development, and extensive proliferative growth of the juvenile kidney resulting in dilution of BrdU below the detection level in extra-papillary regions. BrdU-retaining cells; renal stem cells; renal progenitor cells; kidney growth; kidney development

Natural selection optimizes an organism's genotype within the context of its environment. Adaptations to one environment can decrease fitness in another, revealing evolutionary trade-offs. Here, we show that the cost of gene expression underlies a trade-off between growth rate and mating efficiency in the yeast Saccharomyces cerevisiae. During asexual growth, mutations that eliminate the ability to mate provide an [approximately equal to] 2% per-generation growth-rate advantage. Some strains, including most laboratory strains, carry an allele of GPA1 (an upstream component of the mating pathway) that increases mating efficiency by [approximately equal to] 30% per round of mating at the cost of an [approximately equal to] 1% per-generation growth-rate disadvantage. In addition to demonstrating a trade-off between growth rate and mating efficiency, our results illustrate differences in the selective pressures defining fitness in the laboratory versus the natural environment and show that selection, acting on the cost of gene expression, can optimize expression levels and promote gene loss. evolution | GPA1 | mating pathway | Saccharomyces cerevisiae

Relatively little is known about the contribution of [Ca.sup.2+]-dependent and -independent mechanisms in the contractility of neonatal gastrointestinal smooth muscle. We therefore studied [Ca.sup.2+] homeostasis and [Ca.sup.2+] sensitization mechanisms in 10-day-old and adult guinea pig gallbladder smooth muscle to elucidate developmental changes in these processes. Gallbladder contractility was evaluated by isometrical tension recordings from strips, intracellular [Ca.sup.2+] concentration was estimated by epifluorescence microscopy of fura-2-loaded isolated cells, and protein expression and phosphorylation were assessed by Western blot analysis. The neonatal gallbladder contracted significantly less to CCK than adult tissue, but this correlated with an increased [Ca.sup.2+] mobilization, suggesting immaturity of [Ca.sup.2+] sensitization mechanisms. The enhanced [Ca.sup.2+] release in the newborn gallbladder was the result of the increase in the size of the releasable [Ca.sup.2+] pool. Moreover, in neonatal smooth muscle cells, neither the plasma membrane [Ca.sup.2+] pump nor the [Na.sup.+]/[Ca.sup.2+] exchanger collaborate in the extrusion of [Ca.sup.2+]. In contrast, in these cells, there is an increase in phospholamban phosphorylation, which could drive to an overactivity of the sarco(endo)plasmic reticulum [Ca.sup.2+]-ATPase pump. The reduced [Ca.sup.2+] sensitivity in neonatal tissues was demonstrated by the lack of effect to Y-27362, an inhibitor of Rho kinase (ROCK), and GF-109203X, an inhibitor of PKC, on agonist-induced contraction. In addition, the neonatal gallbladder showed lower levels of RhoA, ROCK, PKC, and two effectors [C-kinase-dependent inhibitor of 17 kDa (CPI-17) and myosin phosphatase targetting 1 (MYPT1)] as well as an absence of CPI-17 and MYPT1 phosphorylation in response to agonists. In conclusion, our results indicate that the main mechanisms involved in smooth muscle contractility are under developmental regulation. [Ca.sup.2+]-dependent contraction; [Ca.sup.2+] sensitization; gastrointestinal smooth muscle

Nutritionally at-risk children suffer delays in physical growth and motor and language development. Infectious diseases such as malaria pose an additional risk. We examined the cross-sectional relationships among malaria infection, hemoglobin (Hb) concentration, length-for-age Z-scores (LAZ), motor activity, behavior, and motor and language development in 841 Zanzibari children 5-19 mo old. We used structural equation modeling to test the fit of the data to a theoretical model and to examine the relationships among the variables in 3 age groups (5-9, 10-14, and 15-19 mo). The model fit the data for all age groups. In the youngest and oldest groups, children with higher malaria parasite densities had significantly lower Hb and LAZ. Higher LAZ significantly predicted higher total motor activity, and motor and language development scores in all age groups. In the oldest group, children who had higher Hb had higher motor development and activity scores. Malaria was directly and indirectly related to motor activity in the 10- to 14-mo-old group [standardized total effects, -0.14; direct, -0.10 (P= 0.015); and indirect, -0.038]. The significant fit of the models to the data and the statistical significance of many of the specific pathways highlight the complexities of the relationships between health and nutrition and child development outcomes in this population. In addition, the results suggest that multiple interventions are likely necessary to improve child development outcomes in this population of nutritionally at-risk children and that the potential effectiveness of interventions may differ according to age (i.e. prevention and treatment of anemia, stunting, and malaria).

Steers and heifers were generated from Angus (A) and Belgian Blue (BB) sires mated to Brahman x Hereford (B x H) [F.sub.1] cows to characterize their growth, carcass traits, and LM shear force. A total of 120 B x H cows purchased from 2 herds and 35 bulls (14 A and 21 BB) produced calves during the 5-yr project. After the stocker phase, a representative sample of A- and BB-sired heifers and steers were transported to the Iberia Research Station to be fed a high-concentrate diet. The remaining cattle were transported to a commercial feedlot facility. Each pen of cattle from the commercial feedlot was slaughtered when it was estimated that heifers and steers had 10 mm of fat or greater. The BB-sired calves were heavier at birth (P < 0.01) than the A-sired calves. During the feedlot phase, the A-sired calves gained more BW (P < 0.05) than the BB-sired calves. The BB-sired calves had heavier (P < 0.01) carcass weights than the A-sired calves. This was due to a combination of a heavier final BW and greater dressing percent. Because of their greater muscling and reduced (P < 0.01) fat, carcasses from BB-sired calves had greater yield (P < 0.01) compared with carcasses from A-sired calves. Carcasses from A-sired calves had a greater (P < 0.01) marbling score and greater (P < 0.01) USDA quality grade than carcasses from BB-sired calves. Tenderness, as measured by shear force of the steaks aged for 7 d, was similar for A- and BB-sired calves. However, steaks aged for 14 d from the A-sired calves had a reduced shear force (P < 0.01) compared with steaks from the BB-sired calves. Steer calves were heavier (P < 0.01) at birth and weaning, and had more total BW gain in the feedlot, which resulted in a heavier final BW and HCW compared with the heifers. Steer carcasses also had greater marbling scores and quality grades, whereas the heifer carcasses had larger LM area per 100 kg of carcass weight. In conclusion, the BB-sired calves had heavier carcass weights and greater cutability, whereas the A-sired calves had a greater degree of marbling and greater quality grade, and steaks from carcasses of A-sired calves were more tender as measured by shear force at 14 d. Key words: beef, breed, carcass composition, growth, sex, tenderness

The objective of this study was to evaluate the performance of growing cattle when intensively grazing stockpiled endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte-infected (EN) tall rescue during the winter. The experiment was conducted over 5 consecutive winters. In each year, plots (1 ha each, 4 per treatment) were harvested for hay in August, fertilized in September, and forage was allowed to accumulate until grazing was initiated in early December. Each year, 48 Angus-cross tester cattle (4 per plot) were given a daily allotment of forage, under strip-grazing (frontal grazing) management, with a target residual height of 5 cm. Steers were used the first year, and heifers were used in subsequent years. The grazing periods for determination of pasture ADG were 86 d (yr 1), 70 d (yr 2), 86 d (yr 3), 72 d (yr 4), and 56 d (yr 5). Pasture ADG of cattle did not differ among treatments (P = 0.13) and were 0.51, 0.59, and 0.56 kg/d (SEM 0.03) for E+, E-, and EN, respectively. Serum prolactin concentrations of heifers grazing E+ were less (P < 0.05) than those grazing E- and EN during all years except yr 2. In yr 2, E+ and E- did not differ (P = 0.11). Serum prolactin of heifers grazing E- and EN did not differ (P > 0.20) except in yr 4. During yr 4, serum prolactin of heifers grazing E- was greater (P = 0.05) than that of heifers grazing EN. Serum urea-N concentrations (SUN) tended to differ among treatments (P = 0.10) and there was a treatment x year interaction (P = 0.05). During yr 1 through 3, SUN did not differ (P > 0.15) among treatments. However, as the stands aged, E- had a greater invasion of other plant species, which increased the CP content of the sward, thus causing heifers grazing E- during yr 5 to have greater (P < 0.01) SUN than heifers grazing E+ and EN, which did not differ (P = 0.89). Forage disappearance (DM basis) did not differ (P = 0.75) among treatments and was 4.7, 4.7, and 5.0 kg/animal daily (SEM 0.27) for E+, E-, and EN, respectively. Body weight gain per hectare was greater (P = 0.04) for E+ (257 kg) than for E- (220 kg) or EN (228 kg). In most years, animal grazing days on E+ were greater than those on E- or EN. However, in yr 5, animal grazing days did not differ (P > 0.20) among treatments. The use of stockpiled E+ as a source of low-cost winter feed is a viable option for producers, whereas grazing of EN may be more beneficial during the spring and fall, when more severe negative effects of ergot alkaloids have been observed. Key words: endophyte status, growing cattle, stockpiling, tall fescue

Two studies with growing pigs were conducted using the regression analysis technique to estimate the true digestibility of P (TPD) in canola (CM) and soybean (SBM) meals, and quantify the effect of microbial phytase on TPD of CM and SBM. In each study, 48 (Exp. 1) or 36 (Exp. 2) 17-kg barrows were assigned to 6 dietary treatments arranged in a 3 x 2 factorial of 3 graded levels of CM (Exp. 1) or SBM (Exp. 2) at 132, 264, or 396 g/kg, and 2 levels of phytase at 0 or 1,000 units/kg. The total collection method was used to calculate P digestibilities. In Exp. 1, phytase supplementation increased (P < 0.01) the apparent total tract digestibility of P in CM with values ranging from 26 to 33% without phytase and from 57 to 62% with supplemental phytase. Regression of digested P against dietary P intake resulted in a decreased (P < 0.05) TPD estimate of 34.3% for the diet without phytase than the 61.4% TPD estimate for diet with added phytase. In Exp. 2, phytase supplementation improved (P < 0.05) apparent total tract P digestibility for SBM with values ranging from 34.3 to 38.6% without phytase and from 68 to 71.2% with supplemental phytase. True P digestibility estimate for SBM without phytase at 40.9% was different (P < 0.05) from that with added phytase at 70.8%. These results indicate a TPD of 34 or 41% in growing pigs fed CM or SBM and demonstrate that the addition of microbial phytase at 1,000 units/kg improves true digestibility of P in CM and SBM by 78 and 73%, respectively. Key words: canola meal, phosphorus, phytase, pig, soybean meal, true digestibility

Understanding how energy is utilized by the pig, and how the pig responds to changes in dietary energy concentration, is essential information in determining the optimal concentration of dietary energy under farm conditions, which are often highly diverse. The objective of these experiments was to determine how changes in dietary DE concentration, achieved through graded changes in diet composition, would affect the performance and carcass composition of growing pigs. In Exp. 1, which was conducted in a research facility, 300 pigs (31.1 [+ or -] 2.6 kg) were assigned to diets containing 3.09, 3.24, 3.34, 3.42, or 3.57 Mcal of DE/kg. Experiment 2, which was conducted at a commercial swine farm, involved 720 pigs (36.8 [+ or -] 5.9 kg) assigned to diets containing 3.12, 3.30, or 3.43 Mcal of DE/kg. Increased DE concentration was attained by using more wheat, soybean meal, and fat and less barley; true ileal lysine was adjusted as DE increased, and minimal AA:lysine ratios were maintained. In Exp. 1, ADG improved linearly as the energy content of the diet increased (P = 0.03). Feed intake decreased (P < 0.001) and feed efficiency and daily caloric intake improved (P = 0.005) with increased DE content. Variability in growth was not affected by treatment. Carcass index and LM thickness were not affected by increasing dietary DE content; backfat thickness, however, was increased (P < 0.001). In Exp. 2, overall ADG was unaffected by dietary energy content, although an improvement in growth was observed until the pigs reached approximately 80 kg of BW. Overall feed intake decreased with increasing energy content (P = 0.01), although this was not observed during the initial 6 wk of the experiment. Carcass index, lean yield, and backfat were not affected by increasing dietary energy content, whereas LM thickness tended to increase (P = 0.08). The value per pig was unaffected by increasing dietary energy content in both experiments, and returns above feed costs were reduced. Increasing the energy density of the diet for growing pigs through incremental changes in dietary composition had a variable impact on overall growth performance and carcass quality. Increasing the dietary DE had no effect on variations in BW at the time of marketing. Key words: canola oil, dietary energy, digestible energy, swine, tallow

We evaluated the effect of raw potato starch (RPS) on growth performance, postweaning diarrhea, and gastrointestinal microbial populations in weaned piglets. Eighty-four piglets were weaned at 17 [+ or -] 2 d of age with an average BW of 6.0 [+ or -] 0.9 kg. Pigs were blocked by BW and assigned to 1 of 4 diets in a randomized complete block design with 7 replicate pens per diet and 3 pigs per pen. Treatments were 1) a positive control (PC) containing an antibiotic, 2) a negative control (NC) with no RPS and no antibiotic, 3) NC [+ or -] 7% RPS (7% RPS), and 4) NC [+ or -] 14% RPS (14% RPS). Diets were corn-wheat-soybean meal-based and formulated to meet NRC (1998) recommendations. The ADG, ADFI, and G:F ratio were determined weekly. Fecal consistency (FC) scoring was determined daily. After wk 3, 1 pig with a BW closest to the pen mean was killed to evaluate ileal and colonic mucosal-attached Escherichia coli and lactic acid bacteria, as well as digesta pH, VFA, and ammonia N concentrations. The DNA was extracted from ileum and colon digesta and used for molecular microbial evaluations using terminal-RFLP analysis of 16S rDNA genes. The ADG for wk 1 was greater (P < 0.01) for the PC diet, but diet had no effect on ADG during wk 3. The ADFI did not differ among treatments during the first 2 wk, and ADFI was least for 7% RPS diet during wk 3. The NC diet had a greater (P < 0.05) FC score during wk 1 than other treatments, but diet had no effect on FC score during wk 2 and 3. Diets had no effect on the colon lactic acid bacterial counts; however, the PC diet had decreased (P < 0.05) colon E. coli counts than other treatments. Ileum and colon digesta pH and total VFA concentrations did not differ among treatments. Pigs fed with 7 and 14% RPS diets had greater (P < 0.05) ileum ammonia N concentration compared with pigs fed with other diets. There was more diarrhea (P < 0.05) in the 14% than the 7% RPS and control treatments at d 21. This difference correlated with a decline (P < 0.05) in microbial diversity in the colon. We concluded that 7% RPS can be used to prevent postweaning diarrhea in weaned piglets, but there are no effects on growth performance. Key words: antibiotic, diarrhea, Escherichia coli, microbial ecology, raw potato starch

To reduce the impact of animal production on the environment, the CP content of the diet can be reduced by limiting the excess supply of AA. Improving the balance between AA relative to the requirement of the animal implies that we need to have accurate knowledge of the requirement of individual AA. The purpose of this study was to determine the Val requirement in postweaned piglets (12 to 25 kg) because Val is considered to be potentially limiting to performance after Lys, Met (and Cys), Thr, and Trp. The first experiment was carried out to identify a diet limiting in Lys supply. In this experiment, piglets were offered 1 of 3 diets: a low-CP diet containing low or adequate Lys concentrations [providing 1.0 and 1.2% standardized ileal digestible (SID) Lys, respectively] or a normal-CP diet with 1.2% SID Lys. Average daily gain of piglets receiving the diet containing 1.0% SID Lys was significantly less than that of piglets receiving diets containing 1.2% SID Lys at low or normal CP (486 vs. 522 g/d, respectively; P < 0.01). In Exp. 2, four diets with 1.0% SID Lys were used in a 2 x 2 factorial design, in which diets contained 57 or 70% SID Val:Lys in combination with 50 or 60% SID Ile:Lys. Independent of the Ile supply, feed intake and daily BW gain were, respectively, 15 and 20% less in piglets receiving diets providing 57% SID Val:Lys compared with piglets receiving 70% SID Val:Lys (P < 0.001). The Ile content of the diet did not affect feed intake or daily BW gain (P > 0.10). Experiment 3 was conducted to evaluate the response of piglets to an increasing Val supply provided by 2 sources of L-Val differing in the degree of purity. Increasing the Val supply from 58 to 66% SID Val:Lys resulted in a linear increase in both feed intake and daily gain by 24 and 30%, respectively (P < 0.001). No difference was observed between both sources of L-Val (P > 0.10). Experiment 4 was a dose-response study using 5 concentrations of Val supply (ranging from 60 to 80% SID Val:Lys). The estimated SID Val:Lys requirements for maximizing ADFI, ADG, and G:F were, respectively, 74, 70, and 68% using a linear-plateau model, and 81, 75, and 72% using a curvilinear-plateau model. Plasma Val, plasma [alpha]-ketoisovaleric acid, Ile, and Leu concentrations after an overnight fast increased with increasing Val supply (P < 0.001). The results of these experiments indicated that the SID Val:Lys was at least 70%, which was slightly greater than the current NRC recommendation. Key words: branched-chain amino acid, feed intake, growth, pig, requirement, valine

Researchers modeling historical heights have typically relied on the restrictive assumption of a normal distribution, only the mean of which is affected by age, income, nutrition, disease, and similar influences. To avoid these restrictive assumptions, we develop a new semiparametric approach in which covariates are allowed to affect the entire distribution without imposing any parametric shape. We apply our method to a new database of height distributions for Italian provinces, drawn from conscription records, of unprecedented length and geographical disaggregation. Our method allows us to standardize distributions to a single age and calculate moments of the distribution that are comparable through time. Our method also allows us to generate counterfactual distributions for a range of ages, from which we derive age-height profiles. These profiles reveal how the adolescent growth spurt (AGS) distorts the distribution of stature, and they document the earlier and earlier onset of the AGS as living conditions improved over the second half of the nineteenth century. Our new estimates of provincial mean height also reveal a previously unnoticed 'regime switch' from regional convergence to divergence in this period.

Sixty-three Boer crossbred goats were used in 5 separate experiments (Exp. 1 to 5) to evaluate the effects of a commercial probiotic supplement on growth performance (Exp. 1 to 4), diet digestibility (Exp. 5), carcass traits (Exp. 3), and fecal bacterial populations (Exp. 4). Goats were either fed a commercially pelleted concentrate diet and supplemented with a commercial probiotie (PRO) that had shown anecdotal positive effects on goat growth and performance according to local goat producers, or they remained as controls. The dose of PRO used was within the labeled dose for sheep for all studies. For Exp. 1, goat BW and feed intake were measured and G:F was calculated every 7 d for 56 d. For Exp. 2 to 4, BW and feed intake were measured and G:F was calculated every 14 d. The first day of supplementation was considered d 0. Carcass traits were also collected at slaughter on d 57 for Exp. 3, and fecal samples were collected every 14 d for microbial culture for Exp. 4. For Exp. 5, which was a digestibility trial that lasted for 10 d, animals were placed in metabolic pens for collection of feces and orts. Growth performance of goats was not affected by probiotic supplementation, with the exception of performance in Exp. 2, in which ADG and G:F were improved (P < 0.03) in PRO goats compared with control goats on d 56 only (treatment x day interaction; P < 0.05), averaging 0.21 [+ or -] 0.02 kg/d for PRO goats and 0.11 [+ or -] 0.02 kg/d for control goats for ADG and 0.17 [+ or -] 0.02 for PRO goats and 0.10 [+ or -] 0.02 for control goats for G:F. Carcass weights and weights of fabricated cuts (shoulder, loin, leg, rack, shank, and total parts) as well as carcass length, leg circumference, loin eye area, and backfat were not influenced by PRO supplementation. Apparent digestibilities of OM, DM, NDF, ADF, CP, and GE (on a DM basis) were similar for the PRO and control treatments. Fecal culture analysis of Escherichia coli and coliforms, Lactobacillus, and Bifidobacterium populations were not influenced by the PRO treatment. Overall, although the PRO treatment affected goat ADG and G:F in Exp. 2, no PRO treatment effects were noted on growth performance for Exp. 1, 3, and 4. Furthermore, the PRO treatment did not affect diet digestibility, carcass traits, or fecal microbial populations in goats. In conclusion, no consistent benefits were noted from supplementing healthy, growing meat goats with PRO. Key words: average daily gain, carcass trait, direct-fed microbial, growth, meat goat, probiotic

This study was conducted at the Research Farm of the Abubakar Tafawa Balewa University, Bauchi, Nigeria to investigate some factors (breed, season, parity, sex, litter size and body condition score) affecting kids' growth performance at various ages. The daily weight gain (overall) of kids reveals non-significant breed effect whereas season, parity, sex, litter size and body condition score had significant (P Key words: Goats, age, daily weight gain, INTRODUCTION Indigenous goats in Nigeria belong to three distinct breeds. The long-legged Sahel found in the arid and Sahel regions, the relatively small body-sized Red Sokoto found in the savanna [...]

Vitamin A (retinoic acid) is known to be an adipogenic factor influencing both in vitro and in vivo cell development. This study aimed to determine its effect on lamb adipose tissue development during the early phase of postnatal development until 100 d of age. Male lambs (n = 24) of the Rasa Aragonesa breed were used. At birth, lambs were assigned to 1 of 2 experimental groups: 1) the control (C) group, which received feed without vitamin A supplementation, and 2) the vitamin A (V) group, which received a supplement of 500,000 IU/animal twice per week from birth to slaughter. The effect of vitamin A supplementation was studied at 16.8 [+ or -] 0.35 kg of BW (58 [+ or -] 0.7 d of age) and at 27.8 [+ or -] 0.78 kg of BW (101 [+ or -] 6.5 d of age). The variables of lamb growth, carcass, LM area, and lipid content were analyzed. To study adipose tissue development, the amount of adipose tissue accumulated, the size and number of adipocytes, and lipogenic enzyme activities (glycerol 3-phosphate dehydrogenase, fatty acid synthase, and glucose 6-phosphate dehydrogenase) of the omental, perirenal, and s.c. depots were quantified. Results showed that vitamin A supplementation had no influence on growth, carcass variables, LM area, and lipid content during lamb growth but that the number of adipocytes in the perirenal depot was 30% greater in lambs of the V group (P < 0.05) and that these lambs had smaller adipocytes in the omental and perirenal depots (P = 0.06) at 28 kg of BW (101 d of age). These results suggest that the intake of this level of vitamin A during the whole period of growth of the lambs influenced the processes of hyperplasia and hypertrophy in the different adipose depots, depending on their degree of maturity. Key words: adipose tissue, growth, lamb, vitamin A

The objective of this study was to quantify the effect of inbreeding on carcass quality, growth rate, live conformation measures, and calving performance in purebred populations of Charolais, Limousin, Simmental, Hereford, and Angus beef cattle using data from Irish commercial and pedigree herds. Variables analyzed are reflective of commercial farming practices. Inbreeding was included in a linear mixed model as either a class variable or a linear continuous variable. Nonlinear effects were nonsignificant across all traits. Inbred animals had decreased carcass weight and less carcass fat. The effects of inbreeding were more pronounced in the British beef breeds. Effects for carcass weight ranged from -0.87 kg (Charolais) to -1.90 kg (Hereford) per 1% increase in inbreeding. Inbred Charolais and Hereford animals were younger at slaughter by 3 and 5 d, respectively, per percentage of increase in inbreeding, whereas the effect of inbreeding on age at slaughter differed significantly with animal sex in the Limousin and Angus breeds. Inbred Limousin and Angus heifers were younger at slaughter by 5 and 7 d, respectively, per percentage of increase in inbreeding. Continental animals were more affected by inbreeding for live muscling and skeletal conformational measurements than the British breeds; inbred animals were smaller and narrower with poorer developed muscle. Calf inbreeding significantly affected perinatal mortality in Charolais, Simmental, and Hereford animals. The effects were dependent upon dam parity and calf sex; however, where significant, the association was always unfavorable. Dam inbreeding significantly affected perinatal mortality in Limousin and Hereford animals. Effects differed by parity in Limousins. Inbred first-parity Angus dams had a greater incidence of dystocia. Although the effects of inbreeding were sometimes significant, they were small and are unlikely to make a large financial effect on commercial beef production in Ireland. Key words: beef cattle, calving performance, carcass, growth, inbreeding depression

As freshwater resources for turfgrass irrigation become more limited, the development of drought-tolerant turf cultivars will be of great value to turf managers. The objective of the following research was to evaluate the field drought tolerance of Kentucky bluegrass (Poa pratensis L.) cultivars and compare their drought tolerance to rooting capacity. Fifty bluegrass entries were established in the field in Albany, OR and evaluated during drought stress (irrigation withheld) events in 2005 and 2006. Drought tolerance was measured, using digital image analysis, as the number of days until a cultivar reached 50% green tissue. In both years, there was a wide range of cultivar responses to drought, with some cultivars losing 50% green tissue 23 d after irrigation was withheld, while others maintained 50% green tissue up to 45 d after irrigation was withheld. Several cultivars, including Mallard, Moonlight, Prosperity, SR2284, Brilliant, and Diva, demonstrated significantly better drought tolerance than other cultivars. Twenty of the cultivars tested under field conditions were also screened for shoot and root growth in a greenhouse study. There was no correlation between shoot growth, root growth, or root:shoot ratios when compared to drought responses in the field. These results demonstrate that there is wide variability in drought tolerance of bluegrasses but factors other than rooting capacity appear to be responsible for those differences.

Climate models predict greater increases in nighttime temperature in the future. The impacts of high nighttime temperature on wheat (Triticum aestivum L.) are not well understood. Objectives of this research were to quantify the impact of high nighttime temperatures during reproductive development on phenology, physiological, vegetative, and yield traits of wheat. Two spring wheat cultivars (Pavon-76 and Seri-82) were grown at optimum temperatures (day/night, 24/14[degrees]C; 16/8 h light/dark photoperiod) from sowing to booting. Thereafter, plants were exposed to four different nighttime temperatures (14, 17, 20, 23[degrees]C) until maturity. The daytime temperature was 24[degrees]C across all treatments. There were significant influences of high nighttime temperatures on physiological, growth, and yield traits, but no cultivar or cultivar by temperature interactions were observed. High nighttime temperatures (>14[degrees]C) decreased photosynthesis after 14 d of stress. Grain yields linearly decreased with increasing nighttime temperatures, leading to lower harvest indices at 20 and 23[degrees]C. High nighttime temperature ([greater than or equal to] 20[degrees]C) decreased spikelet fertility, grains per spike, and grain size. Compared to the control (14[degrees]C), grain filling duration was decreased by 3 and 7 d at night temperatures of 20 and 23[degrees]C, respectively. High nighttime temperature increased the expression of chloroplast protein synthesis elongation factor in both cultivars suggesting possible involvement of this protein in plant response to stress.

The number of pods per unit area is an important component of pod yield of peanut. The goals of this study were to determine the relationships of (i) pod yield with number of pods per unit area and weight per pod and (ii) number of pods per unit area with crop growth rate (CGR) and duration during the different developmental stages. Fifteen peanut lines were tested at Khon Kaen University in Northeast Thailand during the 2002 and 2003 rainy and the 2003 and 2004 dry seasons. Data were recorded on developmental stages, biomass, pod yield, and yield components. The CGRs were calculated for different developmental periods. Results showed a positive linear relationship between pod yield and number of pods per unit area across genotypes and seasons ([R.sup.2] = 0.69; P > F < 0.0001), but no relationship was observed between pod yield and weight per pod ([R.sup.2] = 0.001; P > F = 0.85). A significant relationship between number of pods per unit area and CGR among the test genotypes was found only during the period from R6 to R7 ([R.sup.2] = 0.44; P > F = 0.007), and the same relationship across seasons was significant ([R.sup.2] = 0.45; P > F < 0.001) only during the period from planting to R4. These results indicate that number of pods per unit area is the major determinant for pod-yield differences among peanut lines, and that the differences among lines for this trait are influenced by CGR during the period from R6 to R7.