scholarly journals Genetic Effect and Growth Curve Parameter Estimation under Heat Stress in Slow-Growing Thai Native Chickens

2021 ◽  
Vol 8 (12) ◽  
pp. 297
Author(s):  
Wuttigrai Boonkum ◽  
Monchai Duangjinda ◽  
Srinuan Kananit ◽  
Vibuntita Chankitisakul ◽  
Wootichai Kenchaiwong
Keyword(s):  
Growth Rate ◽  
Heat Stress ◽  
Growth Performance ◽  
Growth Curve ◽  
Growth Rates ◽  
Stress Effect ◽  
Gompertz Function ◽  
Chicken Breeds ◽  
Native Chickens ◽  
Slow Growing

Heat stress is becoming a major problem because it limits growth in poultry production, especially in tropical areas. The development of genetic lines of Thai native chickens (TNC) which can tolerate the tropical climate with the least compromise on growth performance is therefore necessary. This research aims to analyze the appropriate growth curve function and to estimate the effect of heat stress on the genetic absolute growth rate (AGR) in TNC and Thai synthetic chickens (TSC). The data comprised 35,355 records for body weight from hatching to slaughtering weight of 7241 TNC and 10,220 records of 2022 TSC. The best-fitting growth curve was investigated from three nonlinear regression models (von Bertalanffy, Gompertz, and logistic) and used to analyze the individual AGR. In addition, a repeatability test-day model on the temperature-humidity index (THI) function was used to estimate the genetic parameters for heat stress. The Gompertz function produced the lowest mean squared error (MSE) and Akaike information criterion (AIC) and highest the pseudo-coefficient of determination (Pseudo-R2) in both chicken breeds. The growth rates in TSC were higher than TNC; the growth rates of males were greater than females, but the age at inflection point in females was lower than in males in both chicken breeds. The THI threshold started at 76. The heritability of the AGR was 0.23 and 0.18 in TNC and TSC, respectively. The additive variance and permanent environmental variance of the heat stress effect increased sharply after the THI of 76. The growth rate decreased more severely in TSC than TNC. In conclusion, the Gompertz function can be applied with the THI to evaluate genetic performance for heat tolerance and increase growth performance in slow-growing chicken.

scholarly journals Breast meat quality of chickens with divergent growth rates and its relation to growth curve parameters

2017 ◽  
Vol 60 (4) ◽  
pp. 427-437 ◽  
Author(s):  
Philipp C. Muth ◽  
Anne Valle Zárate
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Meat Quality ◽  
Growth Curve ◽  
Growth Rates ◽  
Cooking Loss ◽  
Growth Potential ◽  
Breast Meat ◽  
Fast Growing ◽  
Slow Growing

Abstract. The effects of the increase of body weight of contemporary broilers during growth on functional meat quality and color characteristics of the chicken breast muscle are controversially debated. Therefore, male chickens (n = 264) of a fast-growing commercial broiler (Ross 308) and two slow-growing experimental meat-type chicken lines were compared at equal age and at similar body weight in order to investigate the effect of growth rate on selected functional breast meat traits and meat color. Additionally, the breast meat characteristics of birds with different growth profiles were compared within lines. When the body weight of commercial broilers reached about 40 to 60 % of their growth potential, they exhibited particularly high ultimate pH values compared with slow-growing lines. The ability of the meat of fast-growing broilers to retain water during cooking was impaired (5 to 16 percentage points increased cooking loss compared to slow-growing lines), which, in contrast to pH, was only marginally affected by body weight and/or age at slaughter. No unfavorable correlations of breast meat quality traits with the growth profile, represented by growth curve parameters derived from the Gompertz–Laird equation, were detected within any of the investigated chicken lines. It is noteworthy that the associations of ultimate pH and cooking loss with maximum growth speed indicate a non-linear relationship. Thus, some of the functional characteristics of breast meat of the fast-growing broiler resembled the white-striping defect described for poultry meat, but the hypothesis that selection on increased growth rates is detrimental for meat quality per se could not be confirmed. In fact, an elevated growth potential in particular, i.e., body weight at maturity, could have some beneficial effects for the water-holding capacity of breast meat, regardless of the genotypic growth rate.

GROWTH OF THE SALMON EMBRYO

1943 ◽  
Vol 21d (2) ◽  
pp. 19-33 ◽  
Author(s):  
F. R. Hayes ◽  
F. H. Armstrong
Keyword(s):  
Growth Rate ◽  
Atlantic Salmon ◽  
Growth Curve ◽  
Growth Rates ◽  
Growth Cycle ◽  
Quantitative Relation ◽  
Random Errors ◽  
Relative Growth ◽  
Cycle Growth ◽  
Zero Time

Wet and dry weights of Atlantic salmon are given up to the end of yolk sac absorption, and from them the growth rates are determined. Attempts are made to smooth the growth curve by the methods of Brody, Murray-Schmalhausen, and MacDowell et al. Of these the last is best taking zero time as nine days after fertilization. It is concluded that, as to weight, the interval considered ends before the point of inflection of a Sachs growth cycle. Growth in length, however, represents a complete cycle, hence there can be no simple quantitative relation between length and weight. Deviations from the smoothly descending relative growth rate (RGR or Minot) curve are considered, with the conclusion that all such irregularities so far presented can be attributed to random errors (except possibly the posthatching rise in RGR of the trout at 12° reported by Wood). In general weighing is not sufficiently sensitive as a method, to permit a detailed description of the RGR.

Effect of protozoan predation on relative abundance of fast- and slow-growing bacteria

1989 ◽  
Vol 35 (5) ◽  
pp. 578-582 ◽  
Author(s):  
James L. Sinclair ◽  
Martin Alexander
Keyword(s):  
Growth Rate ◽  
Bacterial Community ◽  
Relative Abundance ◽  
Growth Rates ◽  
Bacterial Species ◽  
Test Species ◽  
Fast Growing ◽  
Population Sizes ◽  
Slow Growing ◽  
Fast Growing Species

The survival of six bacterial species that had different growth rates was tested in raw sewage and sewage that was rendered free of protozoa. When test bacteria were added to protozoa-free sewage at densities of approximately 105 to 106 cells/mL, five of the six species did not decline below 105 cells/mL. If protozoa were present, the population sizes of all test species were markedly reduced, but bacterial species able to grow faster in artificial media had the larger number of survivors. When the same bacteria were inoculated into protozoa-free sewage at densities of less than 103 cells/mL, only the three species able to grow quickly in artificial media increased in abundance. When the six species were inoculated at the same densities into sewage containing protozoa, the three slow-growing species were rapidly eliminated, and two of the three fast-growing species survived in detectable numbers. We suggest that in environments with intense protozoan predation, protozoa may alter the composition of the bacterial community by eliminating slow-growing bacteria.Key words: growth rate, predation, protozoa, sewage.

Growth-Rates of the Bandicoot Isoodon-Macrourus and the Brushtail Possum Trichosurus-Vulpecula

1993 ◽  
Vol 41 (2) ◽  
pp. 141 ◽  
Author(s):  
RT Gemmell ◽  
JK Hendrikz
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Growth Curve ◽  
Growth Rates ◽  
Post Partum ◽  
Quadratic Equation ◽  
The Body ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Iterative Analysis

Although the bandicoot Isoodon macrourus and the brushtail possum Trichosurus vulpecula give birth to similar-size young, about 200 mg, the pouch young of the bandicoot grow more quickly than those of the possum. The bandicoot is weaned at 59 days when the body weight is between 90 and 250 g. A young possum weighs about 20 g at Day 60 and between 780 and 1031 g when weaned at Day 170-180 post partum. The body weight of both species has been described previously as a continuous curve expressed by a quadratic equation. In this study, instead of assuming the growth curve to be continuous, the growth curve has been expressed as two components. The growth rates of both species were similar from birth until Day 12 post partum; the bandicoot then had a faster growth rate. The results from iterative analysis indicated a change in growth rate at Day 30 (data for Days 31 and 32 were missing) and Day 96 post partum for the bandicoot and possum, respectively. Thus, both marsupials showed a change in growth rate as hair appeared, eyes opened and the young first left the pouch.

Measurement of Age and Growth Rate in the Crustose Saxicolous Lichen Caloplaca Trachyphylla Using 14C Accelerator Mass Spectrometry

2000 ◽  
Vol 32 (4) ◽  
pp. 399-403 ◽  
Author(s):  
B. M. Clark ◽  
N. F. Mangelson ◽  
L. L. St. Clair ◽  
L. B. Rees ◽  
G. S. Bench ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Growth Rate ◽  
Growth Curve ◽  
Linear Dependence ◽  
Growth Rates ◽  
Accelerator Mass Spectrometry ◽  
Radial Growth ◽  
Age And Growth ◽  
Radial Position ◽  
Radial Growth Rate

AbstractSections of the crustose saxicolous lichen, Caloplaca trachyphylla, were dated using 14C accelerator mass spectrometry (AMS). The data show a stron linear dependence of radial position on time (r=0.993), suggesting a constant radial growth rate. This specimen had averaged a marginal growth rate of 1.48 mm/year. Extrapolation of the growth curve yields a thallus age of 20 years. These data demonstrate the feasibility of using AMS technology to precisely date lichen tissues and determine growth rates of lichen thalli.

Growth curve models for commercial pullets under severe heat stress condition

2009 ◽  
Vol 2009 ◽  
pp. 234-234
Author(s):  
J Fayazi ◽  
M R Ghorbani ◽  
M Nazari ◽  
J Momeni ◽  
A Jaferian ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Heat Stress ◽  
Growth Curve ◽  
Egg Production ◽  
Harmful Effect ◽  
The Body ◽  
Basic Knowledge ◽  
Growing Period ◽  
Severe Heat Stress

The objectives of our study were to propose a growth curve and to develop a mathematical model to describe the body weight of pullet experiencing severe heat stress (42°C). Poultry producers who raise their own replacement pullets can control their pullet’s growth, condition and development. Many of the problems which occur during the early part of lay can be traced back to insufficient or improper type of body weight attained during the various stages of the growing period. In order to avoid these problems, the body weight of pullets must be controlled. Rearing conditions for pullets vary depending on environmental pressures and can affect growth rate. Without the basic knowledge of the flock grow-out, it is virtually impossible to understand and possibly solve problems which may later occur during the laying period. It must be kept in mind that once egg production begins, it is too late to solve problems resulting from growing period. The two most important criteria of pullet quality are uniformity within the flock and proper body weight at a specific age. Almost anything that adversely affects a pullet will usually be reflected in lower body weights and poorer flock uniformity. High ambient temperatures can be devastating to commercial pullet growth rate; coupled with high humidity they can have an even more harmful effect on proper and recommended body weight. Heat stress interferes with the poultry comfort and suppresses performance efficiency. In order to verify the effect of heat stress on pullet growth rate, many curve modelled, fitted and verified to proposed best one.

scholarly journals A growth model for laboratory rats

1974 ◽  
Vol 8 (3) ◽  
pp. 329-335
Author(s):  
M. N. Brunden ◽  
H. W.Clapp ◽  
L. L. Heun
Keyword(s):  
Growth Rate ◽  
Growth Model ◽  
Growth Curve ◽  
Efficient Method ◽  
Growth Rates ◽  
Average Weight ◽  
Laboratory Rats ◽  
Weekly Sample ◽  
Future Date

Our rats are generally requisitioned by bodyweight. It is imperative, therefore, that an efficient method be used for determining the weights of animals in a given location to fill order commitments. Given any beginning average weight at an age on or after 21 days this method predicts the average weight of animals in a cage for any future date within practical limits. It assumes that the growth curve may be adequately represented by linear segments. The method also accounts for the differing growth rates of light and heavy animals. In order to maintain current estimates of these growth rates, we take a small weekly sample of representative rats at 21 days of age. These animals are reweighed weekly to provide data for continual reestimation of the growth-rate parameters used for prediction.

scholarly journals Specific Growth Rate Determines the Sensitivity of Escherichia coli to Thermal, UVA, and Solar Disinfection

2006 ◽  
Vol 72 (4) ◽  
pp. 2586-2593 ◽  
Author(s):  
Michael Berney ◽  
Hans-Ulrich Weilenmann ◽  
Julian Ihssen ◽  
Claudio Bassin ◽  
Thomas Egli
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
E Coli ◽  
Mild Heat ◽  
Uva Light ◽  
Specific Growth Rates ◽  
Slow Growing

ABSTRACT Knowledge about the sensitivity of the test organism is essential for the evaluation of any disinfection method. In this work we show that sensitivity of Escherichia coli MG1655 to three physical stresses (mild heat, UVA light, and sunlight) that are relevant in the disinfection of drinking water with solar radiation is determined by the specific growth rate of the culture. Batch- and chemostat-cultivated cells from cultures with similar specific growth rates showed similar stress sensitivities. Generally, fast-growing cells were more sensitive to the stresses than slow-growing cells. For example, slow-growing chemostat-cultivated cells (D = 0.08 h−1) and stationary-phase bacteria from batch culture that were exposed to mild heat had very similar T 90 (time until 90% of the population is inactivated) values (T 90, chemostat = 2.66 h; T 90, batch = 2.62 h), whereas T 90 for cells growing at a μ of 0.9 h−1 was 0.2 h. We present evidence that the stress sensitivity of E. coli is correlated with the intracellular level of the alternative sigma factor RpoS. This is also supported by the fact that E. coli rpoS mutant cells were more stress sensitive than the parent strain by factors of 4.9 (mild heat), 5.3 (UVA light), and 4.1 (sunlight). Furthermore, modeling of inactivation curves with GInaFiT revealed that the shape of inactivation curves changed depending on the specific growth rate. Inactivation curves of cells from fast-growing cultures (μ = 1.0 h−1) that were irradiated with UVA light showed a tailing effect, while for slow-growing cultures (μ = 0.3 h−1), inactivation curves with shoulders were obtained. Our findings emphasize the need for accurate reporting of specific growth rates and detailed culture conditions in disinfection studies to allow comparison of data from different studies and laboratories and sound interpretation of the data obtained.

scholarly journals Polypeptide-chain-elongation rate in Escherichia coli B/r as a function of growth rate

1976 ◽  
Vol 160 (2) ◽  
pp. 185-194 ◽  
Author(s):  
R Young ◽  
H Bremer
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Growth Rate ◽  
Growth Rates ◽  
Elongation Rate ◽  
Peptide Chain ◽  
Chain Elongation ◽  
Slow Growing ◽  
Kinetics Of ◽  
Escherichia Coli B

By evaluating the kinetics of radioactive labelling of nascent and finished polypeptides, the peptide-chain elongation rate for Escherichia coli B/r at three different growth rates (mu) was determined to be 17 amino acids/s for the fast-growing cells (mu equals 1.3 and 2.0 doublings/h) and 12 amino acids/s for slow-growing cells (mu equals 0.67 doublings/h). The results agree with the growth-rate-dependence of the rate of peptide-chain elongation found for the translation of newly induced β-galactosidase messenger in this strain and under these conditions of growth [Dalbow & Young (1975) Biochem. J. 150, 13-20]. Together with the previously observed ribosome efficiency at these growth rates [Dennis & Bremer (1974) J. Mol. Biol. 84, 407-422] the results indicate that the fraction of ribosomes engaged in protein synthesis is about 0.8 at all three growth rates.

scholarly journals 221 Effect of varying growth rates on early and aged pork loin and chop quality

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 46-47
Author(s):  
Emily D Schunke ◽  
Jessica E Lowell ◽  
Chad A Stahl ◽  
Bailey N Harsh ◽  
Anna C Dilger
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Average Daily Gain ◽  
Growing Pigs ◽  
Pork Industry ◽  
Fast Growing ◽  
Visual Color ◽  
Main Effects ◽  
Slow Growing ◽  
Daily Gain

Abstract The pork industry has observed an upward trend in ending live weights, resulting in heavier hot carcass weights (HCW). Heavier HCW positively affects loin tenderness; however, the mechanism of this effect is unclear. One possibility is increased growth rate, associated with greater HCW, resulting in more tender loins. The objective was to determine the effect of growth rate on early and aged pork quality. Pigs (N=634) were divided into three groups based on average daily gain (kg/d) from 12-26wk of age; slow (< 0.96kg/d, n=96), intermediate (0.96-1.16kg/d, n=452), and fast (≥ 1.17kg/d, n=86). The MIXED procedure of SAS was used to evaluate the main effects of growth rate, breed, sex, and their interactions on loin quality. Birth and weaning weight did not differ between growth rate (P≥0.15) but, overall ADG was increased (P<0.001) in fast growing pigs by 0.15 kg/d. Fast and intermediate growing pigs had darker loins (P=0.03) by 0.23 units. Intermediate growing pigs had firmer loins (P=0.04) by 0.07 units. Ventral a* increased as growth rate increased (P=0.04) indicating fast growing pigs had the reddest loins (9.77 vs. 9.26 vs. 8.99). Aged ventral marbling, ultimate pH, purge loss, cook loss, instrumental tenderness, and chop moisture and extractable lipid did not differ (P≥0.32) between growth rate groups. Duroc-sired pigs had increased tenth rib back fat amongst all growth rate groups, but the magnitude of difference was much greater in the slow and intermediate groups. Between all growth rate groups, slow growing Pietrain-sired Pigs had the smallest loineye areas (LEA). Carcass yield, bone-in carcass cutting yield, and boneless carcass cutting yield did not differ (P≥0.37) between growth rate groups. While fast growth rates improved aged ventral visual color, instrumental tenderness did not differ between growth rate groups.

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