Adjustment of nonlinear models and growth parameters and body nutrient deposition in meat-type and laying quail

This project utilized two live-animal populations in an integrated research program to identify molecular markers for immune response and disease resistance. The populations each had their foundation from meat-type commercial breeder chicken lines of their respective countries. Investigations effectively used unique availability of resources in each country to study commercial-type environments in Israel and line-crosses with diverse inbred lines in the US. Two bacterial systems were investigated to cover both respiratory and gastrointestinal, and primary and secondary, infections. Individual experimental groups of animals were evaluated for combinations of vaccine antibody levels, response to pathogen challenge, growth parameters, genetic background and molecular markers. The positive association of antibody level with resistance to disease was confirmed. Effectiveness of genetic selection for vaccine antibody response level was demonstrated. Molecular markers, both inside and outside the MHC region, were associated with antibody response and resistance to disease. Markers were shown to have a generalized effect, by association with multiple traits of immune response and disease resistance. The impact of genetic background on marker effect was shown to be important. The overall results demonstrate the effectiveness of selection on vaccine antibody response and the potential of molecular marker-assisted selection to improve efficiency of production of meat-type chickens by reducing genetic susceptibility to disease.

Download Full-text

Quantifying the Growth of Female Pacific Hake (Merluccius productus): An Example of Measuring Uncertainty and Bias in Non-linear Parameter Estimation

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-074 ◽

1990 ◽

Vol 47 (4) ◽

pp. 672-681 ◽

Cited By ~ 10

Author(s):

David W. Welch ◽

Gordon A. McFarlane

Keyword(s):

Growth Parameters ◽

Growth Models ◽

Nonlinear Models ◽

Somatic Growth ◽

Maximum Size ◽

Diagnostic Methods ◽

Parameter Estimates ◽

Intrinsic Variability ◽

Merluccius Productus ◽

Size At Age

Estimates of size-at-age are commonly reported in fisheries studies, but statistical uncertainty and intrinsic variability in the growth parameters are less frequently examined. We examine these questions using recently-developed statistical methods for quantifying uncertainty and bias in parameter estimates for nonlinear models with independent and additive Gaussian errors. We also describe diagnostic methods to determine when the usual method for examining parameter uncertainty, linearization, is unacceptable. Both our review and our approach to uncertainty are generally applicable to nonlinear estimation, and not solely restricted to growth models. We illustrate our approach with length-at-age data for female Pacific hake (Merluccius productus) from Georgia Strait, British Columbia. Between-year variation in somatic growth seems to be restricted to the two von Bertalanffy growth parameters K and L∞. Mean asymptotic length declined by about 10% since the late 1970's while the parameter K nearly tripled in value. Closer examination showed that the decline in somatic growth was restricted to the maximum size attained. We argue that the changes are most consistent with selective removal of the largest individuals from the population by the fishery, rather than a response of growth rates to either environmental or density-dependent factors.

Download Full-text

Growth curves in meat-type and laying quail: a Bayesian perspective

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n4supl1p2743 ◽

2017 ◽

Vol 38 (4Supl1) ◽

pp. 2743

Author(s):

Robson Marcelo Rossi ◽

Daiane De Oliveira Grieser ◽

Vagner De Almeida Conselvan ◽

Simara Márcia Marcato

Keyword(s):

Body Weight ◽

Bayesian Approach ◽

Goodness Of Fit ◽

Nonlinear Models ◽

Growth Curves ◽

Gompertz Model ◽

Body Growth ◽

Coturnix Coturnix ◽

Body Weight Data ◽

Meat Type

The aim of this study was to assess the goodness of fit for nonlinear models, using the best model to describe body growth curves, comparing the parameters obtained for gender and one meat-type (Coturnix coturnix coturnix) and two laying (Coturnix coturnix japonica) quail strains, as well as nesting via MCMC (Markov chain Monte Carlo processes) methods under a Bayesian approach. A total of 1,350 one-day-old mixed quail were used: 400 of meat-type, 450 of yellow laying, and 500 of red laying strains distributed in a completely randomized design with three treatments (each treatment corresponded to one strain) and five replications. The experimental period consisted of 1 to 42 days of age. At 21 days of age, quail sexing was performed by means of sexual dimorphism, being individually identified at one day of age with numbered rings, allowing determining growth curves by gender. Birds were reared in a conventional system, fed ad libitum with diets formulated to meet nutritional requirements. Body weight was determined weekly and assessed using nonlinear models: Logistic, Brody, Von Bertalanffy, and Gompertz, whose parameters were estimated under a Bayesian approach via MCMC algorithm by means of BRugs package from the software R. DIC (Deviance Information Criterion) criterion was used to select the best nonlinear model, i.e. the lower the DIC value is, the better the model goodness of fit to the data. Gompertz model was better adjusted to the data regardless the gender or strain. Meat-type quail had the highest asymptotic weights and the highest age at which growth rate was maximum, followed by red and yellow strains. All nestings presented significant differences (p < 0.05) between gender for contrasted parameters. Meat-type, yellow, and red females presented values significantly (p < 0.05) higher for asymptotic weight (370, 203, and 215 g, respectively) when compared to males (274, 131, and 143 g, respectively), which were earlier in body growth. Gompertz model was better adjusted to body weight data of quail regardless the gender or strain and the Bayesian approach allowed obtaining accurate estimations. Meat-type strain presented the highest body asymptotic weight, followed by red and yellow laying strains. Females presented higher asymptotic weight than that found for males of their respective strains but were later in growth.

Download Full-text

Growth curves in meat-type and laying quail: a Bayesian perspective

Semina Ciências Agrárias ◽

10.5433/1679-0359.2017v38n4suplp2743 ◽

2017 ◽

Vol 38 (4Supl1) ◽

pp. 2743 ◽

Cited By ~ 1

Author(s):

Robson Marcelo Rossi ◽

Daiane De Oliveira Grieser ◽

Vagner De Almeida Conselvan ◽

Simara Márcia Marcato

Keyword(s):

Body Weight ◽

Bayesian Approach ◽

Goodness Of Fit ◽

Nonlinear Models ◽

Growth Curves ◽

Gompertz Model ◽

Body Growth ◽

Coturnix Coturnix ◽

Body Weight Data ◽

Meat Type

The aim of this study was to assess the goodness of fit for nonlinear models, using the best model to describe body growth curves, comparing the parameters obtained for gender and one meat-type (Coturnix coturnix coturnix) and two laying (Coturnix coturnix japonica) quail strains, as well as nesting via MCMC (Markov chain Monte Carlo processes) methods under a Bayesian approach. A total of 1,350 one-day-old mixed quail were used: 400 of meat-type, 450 of yellow laying, and 500 of red laying strains distributed in a completely randomized design with three treatments (each treatment corresponded to one strain) and five replications. The experimental period consisted of 1 to 42 days of age. At 21 days of age, quail sexing was performed by means of sexual dimorphism, being individually identified at one day of age with numbered rings, allowing determining growth curves by gender. Birds were reared in a conventional system, fed ad libitum with diets formulated to meet nutritional requirements. Body weight was determined weekly and assessed using nonlinear models: Logistic, Brody, Von Bertalanffy, and Gompertz, whose parameters were estimated under a Bayesian approach via MCMC algorithm by means of BRugs package from the software R. DIC (Deviance Information Criterion) criterion was used to select the best nonlinear model, i.e. the lower the DIC value is, the better the model goodness of fit to the data. Gompertz model was better adjusted to the data regardless the gender or strain. Meat-type quail had the highest asymptotic weights and the highest age at which growth rate was maximum, followed by red and yellow strains. All nestings presented significant differences (p < 0.05) between gender for contrasted parameters. Meat-type, yellow, and red females presented values significantly (p < 0.05) higher for asymptotic weight (370, 203, and 215 g, respectively) when compared to males (274, 131, and 143 g, respectively), which were earlier in body growth. Gompertz model was better adjusted to body weight data of quail regardless the gender or strain and the Bayesian approach allowed obtaining accurate estimations. Meat-type strain presented the highest body asymptotic weight, followed by red and yellow laying strains. Females presented higher asymptotic weight than that found for males of their respective strains but were later in growth.

Download Full-text

Does the Optimal Dietary Methionine to Cysteine Ratio in Diets for Growing Chickens Respond to High Inclusion Rates of Insect Meal from Hermetia illucens?

Animals ◽

10.3390/ani8110187 ◽

2018 ◽

Vol 8 (11) ◽

pp. 187 ◽

Cited By ~ 4

Author(s):

Anne Brede ◽

Christian Wecke ◽

Frank Liebert

Keyword(s):

Protein Quality ◽

Growth Parameters ◽

Control Diet ◽

Optimal Growth ◽

The Body ◽

Sulfur Amino Acids ◽

Hermetia Illucens ◽

Complete Replacement ◽

Nutrient Deposition ◽

Previous Assumption

The dietary methionine:cysteine (Met:Cys) ratio (MCR) is an important factor influencing the optimal growth of chickens. Therefore, this study aimed to contribute to the assessment of the optimal dietary MCR in diets with the complete replacement of soybean meal (SBM) by a partly defatted larvae meal of Hermetia illucens (HM). A growth study with 240 male meat-type chickens (Ross 308) was conducted, also assessing the body nutrient deposition both at the end of the starter (day 21) and the grower (day 35) period. Birds were fed experimental diets based on wheat, maize, and insect meal (23%/21% HM in starter/grower diets). Sulfur amino acids were created as the limiting AA in diets with graded MCR (40:60; 45:55; 50:50; 55:45; 60:40). The control diet contained SBM instead of HM with a MCR of 50:50. The current results based on growth parameters, dietary protein quality, and Met efficiency data gave support to the previous assumption of an ideal MCR of 50:50, which was also valid in diets with a high proportion of insect meal. The lowest MCR of 40:60 led to significantly impaired feed intake and growth of the birds, while the response to the highest MCR (60:40) was moderate.

Download Full-text

Estimation of growth parameters of body weight and body nutrient deposition in males and females of meat- and laying-type quail using the Gompertz model

Revista Brasileira de Zootecnia ◽

10.1590/rbz4720170083 ◽

2018 ◽

Vol 47 (0) ◽

Author(s):

Daiane de Oliveira Grieser ◽

Simara Márcia Marcato ◽

Antonio Claudio Furlan ◽

Vittor Zancanela ◽

Ana Paula Del Vesco ◽

...

Keyword(s):

Body Weight ◽

Growth Parameters ◽

Gompertz Model ◽

Nutrient Deposition ◽

Males And Females

Download Full-text

Studies of Ge/Si(100) and Observation of Atomic Steps on Si(100) using Biassed Secondary Electron Imaging in a UHV STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010018029x ◽

1990 ◽

Vol 48 (1) ◽

pp. 308-309

Author(s):

Mohan Krishnamurthy ◽

Jeff S. Drucker ◽

John A. Venablest

Keyword(s):

Secondary Electron ◽

Critical Thickness ◽

Surface Defects ◽

Film Growth ◽

Growth Parameters ◽

High Vacuum ◽

Ultra High Vacuum ◽

Surface Steps ◽

Epitaxial Crystal Growth ◽

Electron Imaging

Secondary Electron Imaging (SEI) has become a useful mode of studying surfaces in SEM[1] and STEM[2,3] instruments. Samples have been biassed (b-SEI) to provide increased sensitivity to topographic and thin film deposits in ultra high vacuum (UHV)-SEM[1,4]; but this has not generally been done in previous STEM studies. The recently developed UHV-STEM ( codenamed MIDAS) at ASU has efficient collection of secondary electrons using a 'parallelizer' and full sample preparation system[5]. Here we report in-situ deposition and annealing studies on the Ge/Si(100) epitaxial system, and the observation of surface steps on vicinal Si(100) using b-SEI under UHV conditions in MIDAS.Epitaxial crystal growth has previously been studied using SEM and SAM based experiments [4]. The influence of surface defects such as steps on epitaxial growth requires study with high spatial resolution, which we report for the Ge/Si(100) system. Ge grows on Si(100) in the Stranski-Krastonov growth mode wherein it forms pseudomorphic layers for the first 3-4 ML (critical thickness) and beyond which it clusters into islands[6]. In the present experiment, Ge was deposited onto clean Si(100) substrates misoriented 1° and 5° toward <110>. This was done using a mini MBE Knudsen cell at base pressure ~ 5×10-11 mbar and at typical rates of 0.1ML/min (1ML =0.14nm). Depositions just above the critical thickness were done for substrates kept at room temperature, 375°C and 525°C. The R T deposits were annealed at 375°C and 525°C for various times. Detailed studies were done of the initial stages of clustering into very fine (∼1nm) Ge islands and their subsequent coarsening and facetting with longer anneals. From the particle size distributions as a function of time and temperature, useful film growth parameters have been obtained. Fig. 1 shows a b-SE image of Ge island size distribution for a R T deposit and anneal at 525°C. Fig.2(a) shows the distribution for a deposition at 375°C and Fig.2(b) shows at a higher magnification a large facetted island of Ge. Fig.3 shows a distribution of very fine islands from a 525°C deposition. A strong contrast is obtained from these islands which are at most a few ML thick and mottled structure can be seen in the background between the islands, especially in Fig.2(a) and Fig.3.

Download Full-text