Bioavailability of zinc sources and their interaction with phytates in broilers and piglets

Zinc (Zn) is essential for swine and poultry and native Zn concentrations in feedstuffs are too low to meet their Zn requirement. Dietary Zn bioavailability is affected by phytate, phytase and Zn supplemented in organic form is considered as more bioavailable than inorganic sources. A meta-analysis using GLM procedures was processed using broiler and piglet databases to investigate, within the physiological response of Zn, (1) the bioavailability of inorganic and organic Zn sources (Analysis I); (2) the bioavailability of native and inorganic Zn dependent from dietary phytates, vegetal and supplemental phytase activity (Analysis II). Analysis I: the bioavailability of organic Zn relative to inorganic Zn sources ranged, depending on the variable, from 85 to 117 never different from 100 (P > 0.05). The coefficients of determination of the regressions were 0.91 in broilers and above 0.89 in piglets. Analysis II: in broilers, bone Zn was explained by supplemental Zn (linear and quadratic, P 0.05). The coefficients of determination of the regressions were 0.92 in broilers and above 0.92 in piglets. The results from the two meta-analyses suggest that (1) broilers and piglets use supplemented Zn, independent from Zn source; (2) broiler use native Zn and the use is slightly enhanced with supplemental phytase; (3) however, piglets are limited in the use of native Zn because of the antagonism of non-hydrolyzed dietary phytate. This explains the higher efficacy of phytase in improving Zn availability in this speci

China’s Outward Foreign Direct Investment and International Investment Law

As China’s outward foreign direct investment (FDI) has grown, its approach to international investment agreements (IIAs) has changed. China is now one of the world’s most important outward investors, with Chinese FDI facing widespread criticism. The challenge for China is to adapt to this new configuration of interests stemming from these developments, both in terms of its national policies and the contents of its IIAs. In so doing, it is likely to influence, perhaps significantly, the further evolution of international investment law. This article deals briefly with the salient features of China’s outward FDI and the policies that support it (Section A); the perception and reception of China’s outward FDI in key host countries (Section B); and the changing nature of the country’s approach to international investment treaties (Section C). The article concludes (Section D) with a brief review and outlook

Repeatability of traits for characterizing feed intake patterns in dairy goats: a basis for phenotyping in the precision farming context

International audienceIn ruminants, feeding behaviour variables are parameters involved in feed efficiency that show variation among individuals. This study aimed to evaluate during the first two production cycles in ruminants the repeatability of feed intake pattern, which is an important aspect of feeding behaviour. Thirty-five dairy goats from Alpine or Saanen breeds were housed in individual pens at four periods (end of first gestation, middle of first and second lactations and middle of second gestation which is also the end of first lactation) and fed a total mixed ration (TMR) ad libitum. Individual cumulative dry matter intake (DMI) was automatically measured every 2 min during the last 4 days of each period. Feed intake pattern was characterized by several measures related to the quantity of feed eaten or to the rate of intake during the 15 h following the afternoon feed delivery. Two main methods were used: modelling cumulative DMI evolution by an exponential model or by a segmentation-clustering method. The goat ability to sort against dietary fibre was also evaluated. There was a very good repeatability of the aggregate measures between days within a period for a given goat estimated by the day effect within breed and goat, tested on the residual variance (P > 0.95). The correlations between periods were the highest between the second and either the third or fourth periods. With increasing age, goats sorted more against the fibrous part of the TMR and increased their initial rate of intake. Alpine goats ate more slowly than Saanen goats but ate during a longer duration. Principal component analysis (PCA) was performed on all the aggregate measures of feed intake patterns. The factor score plots generated by the PCA highlighted the opposition between the different measures of feed intake patterns and the sorting behaviour. The projection of the animals on the scoring plots showed a breed effect and that there was a continuum for the feed intake pattern of goats. In conclusion, this study showed that the feed intake pattern was highly repeatable for an animal in a given period and between periods. This means that phenotyping goats in a younger age might be of interest, either to select them on feeding behaviour and choose preferentially the slow eaters or to adapt the quantity offered and restrict feed delivery to the fast eaters in order to increase feed efficiency and welfare by limiting the occurrence of acidosis, for example

Review: to be or not to be an identifiable model. Is this a relevant question in animal science modelling?

International audienceWhat is a good (useful) mathematical model in animal science? For models constructed for prediction purposes, the question of model adequacy (usefulness) has been traditionally tackled by statistical analysis applied to observed experimental data relative to model-predicted variables. However, little attention has been paid to analytic tools that exploit the mathematical properties of the model equations. For example, in the context of model calibration, before attempting a numerical estimation of the model parameters, we might want to know if we have any chance of success in estimating a unique best value of the model parameters from available measurements. This question of uniqueness is referred to as structural identifiability; a mathematical property that is defined on the sole basis of the model structure within a hypothetical ideal experiment determined by a setting of model inputs (stimuli) and observable variables (measurements). Structural identifiability analysis applied to dynamic models described by ordinary differential equations (ODE) is a common practice in control engineering and system identification. This analysis demands mathematical technicalities that are beyond the academic background of animal science, which might explain the lack of pervasiveness of identifiability analysis in animal science modelling. To fill this gap, in this paper we address the analysis of structural identifiability from a practitioner perspective by capitalizing on the use of dedicated software tools. Our objectives are (i) to provide a comprehensive explanation of the structural identifiability notion for the community of animal science modelling, (ii) to assess the relevance of identifiability analysis in animal science modelling and (iii) to motivate the community to use identifiability analysis in the modelling practice (when the identifiability question is relevant). We focus our study on ODE models. By using illustrative examples that include published mathematical models describing lactation in cattle, we show how structural identifiability analysis can contribute to advancing mathematical modelling in animal science towards the production of useful models and highly informative experiments. Rather than attempting to impose a systematic identifiability analysis to the modelling community during model developments, we wish to open a window towards the discovery of a powerful tool for model construction and experiment design

Beginning of the End of Cost Competitiveness in CEE Countries - Analysis of Dependence between Labor Costs and Internationalization of the Region

In order to exemplify the above econometric model I carried out empirical analysis of the companies listed on the Warsaw Stock Exchange, identifying the companies for which efficiency-seeking is the main internationalization motive. The analysis of internationalization of 26 companies during the years 1990-2010 clearly shows that a significant part of investments is located outside the territory of Poland, in the countries with lower labor costs. This fact confirms that CEE countries will gradually become less and less attractive in terms of costs not only for MNEs from developed countries but also for the companies originating from transition economies.Głównym celem artykułu jest weryfikacja, czy niski poziom kosztów pracy w Europie Środkowej i Wschodniej będący do tej pory jednym z czynników wpływających na konkurencyjność tego regionu pozostanie nim w dłuższej perspektywie czasowej. W pracy na podstawie próby wszystkich państw UE zbadano zależność pomiędzy poziomem internacjonalizacji (stan odpływu BIZ per capita) a kosztami pracy w sektorze przedsiębiorstw i GNP per capita. Analiza regresji potwierdziła istnienie zależności pomiędzy wyżej wymienionymi czynnikami. Oznacza to, że stopniowy wzrost kosztów pracy w państwach Europy Środkowej i Wschodniej prowadził będzie do stopniowego odpływu BIZ z tego regionu do państw bardziej konkurencyjnych kosztowo. W celu egzemplifikacji powyższych zależności w pracy dodatkowo przedstawiono analizę inwestycji zagranicznych polskich spółek notowanych na GPW, z których to 26 dokonało inwwestycji zagranicznych o wyraźnych motywach związanych z obniżeniem kosztów produkcji. Fakt ten potwierdza powolny spadek konkurencyjności kosztowej polskiej gospodarki, tym samym zmusza do poszukiwania nowych rozwiązań instytucjonalnych mogących utrzymać konkurencyjność polskiej gospodarki w długim okresie