scholarly journals Models for evaluation of growth of performance tested bulls

2008 ◽  
Vol 53 (No. 2) ◽  
pp. 45-54 ◽  
Author(s):  
J. Přibyl ◽  
H. Krejčová ◽  
J. Přibylova ◽  
I. Misztal ◽  
S. Tsuruta ◽  
...  
Keyword(s):  
Growth Curve ◽  
Variance Components ◽  
Legendre Polynomials ◽  
Performance Test ◽  
Live Weight ◽  
Random Regression ◽  
Mild Depression ◽  
Average Growth ◽  
Linear Spline

Before being used for insemination, young bulls of Czech Fleckvieh (CF) are tested for growth at performance-test stations. While at stations, the bulls are weighed monthly. Evaluation included 7 448 bulls with 82 676 records of weight measured from 6 to 520 days of life. In the station-year-period (HYS), which can be prolonged up to 3 months, different groups were tested according to the beginning of growth curve and according to test-days of weighing. Weight analyses were used to handle heterogeneous variability based on age. Legendre Polynomials (LP) with 5 parameters described the average growth curve for HYS classes. Deviations from average curves were decomposed into genetic (G), animal’s permanent environment (PE) and residual (RES) components. Functions of (G) and (PE) were tested using LP random regression (RR) methodology with 5 or 3 parameters and Linear Spline (SP) function with 5 knots. Variance increases with the age of the animals. From 100 to 400 days, heritability was nearly the same with a mild depression in the middle of the period. The average was <I>h</I><sup>2</sup> = 0.31 and ended with <I>h</I><sup>2</sup> = 0.36. Results were similar for variance components, heritability, genetic, environmental and phenotype correlations from different models with different LP and SP functions. Higher RES variability occurred only for LP with 3 parameters. For traits like live weight, the RR should have at least 3 parameters and SP function should be used.

scholarly journals Comparison of different traits to evaluate the growth of bulls

2008 ◽  
Vol 53 (No. 7) ◽  
pp. 273-283 ◽  
Author(s):  
J. Přibyl ◽  
J. Přibylová ◽  
H. Krejčová ◽  
N. Mielenz
Keyword(s):  
Variance Components ◽  
Performance Test ◽  
Live Weight ◽  
Random Regression ◽  
Breeding Values ◽  
Final Weight ◽  
Estimated Breeding Values ◽  
Simple Evaluation ◽  
Growth Of Animals ◽  
Daily Gain

The live weights of 8 243 performance-tested bulls from 100 to 400 days of age were analysed using random regression (RR) and single-trait animal models. Evaluations were done for live weight at 400 days of age and gains from 100 to 400 days of age at various monthly intervals. Estimates of variance components differed depending on the trait definition and model of analysis. Systematic environmental effects explained a higher proportion of variability in the RR for gains than for other definitions of growth. The expected average reliability of estimated breeding values was similar for all methods from 0.42 to 46, but the rankings of animals differed. Determinations (<I>r</I><sup>2</sup>) of breeding values between methods ranged from 0.64 to 0.94. Correlations of the breeding values of progeny at performance-test stations with parents were highest for the evaluation of gains in consecutive intervals evaluated by RR. Correlations of the breeding values of sires from their growth at performance-test stations with the breeding values of groups of progeny at progeny-test stations were from 0.26 to 0.38. Correlations were the highest for RR evaluations of gain using consecutive short intervals. Evaluation of the growth of animals according to daily gains in short consecutive intervals was preferred because more animals and more observations per animal were included in the evaluations, and the growth curve was separated into genetic and non-genetic parts. Simple evaluation of growth according to the final weight or daily gain in a long interval is not entirely correct, since environmental compensatory growth can occur.

scholarly journals Trajectory of body weight of performance tested dual-purpose bulls

2008 ◽  
Vol 52 (No. 10) ◽  
pp. 315-324 ◽  
Author(s):  
J. Přibyl ◽  
H. Krejčová ◽  
J. Přibylová ◽  
I. Misztal ◽  
J. Bohmanová ◽  
...  
Keyword(s):  
Variance Components ◽  
Fixed Effects ◽  
Spline Function ◽  
Performance Test ◽  
Live Weight ◽  
Random Regression ◽  
Dual Purpose ◽  
Basic Model ◽  
Body Weights ◽  
Dual Purpose Cattle

6 508 bulls of dual-purpose cattle at performance-test stations were weighed at intervals of 30 days from birth to 420 days. After all editing a total of 74 558 weight records were available. Live weight was evaluated by orthogonal Legendre Polynomial (LP) of degree 4 and by Linear Spline function (SP) with 5 knots. The fixed effects of test-day-year-station of weighing (TDS) and LP within station-year explain together 97% of variability. Variance components were estimated by REML (REMLF90 programme) taking into account heterogeneous variance during growth. The basic model included fixed effects: TDS, and fixed regression on age (LP<sub>F</sub>), and random regression for additive genetic (SP<sub>G</sub>) and permanent environmental of the animal (SP<sub>PE</sub>) effects. Variability of all components increases with age. During the 50–400 day period the heritability is 0.28 on average. Heritability increases with the age of the animal; it is the highest at the end of the period. Correlations for body weights between different ages of the animal are high.

scholarly journals Genetic parameters for test day milk yield of first lactation Holstein cows estimated by random regression using Legendre polynomials

2008 ◽  
Vol 37 (4) ◽  
pp. 602-608 ◽  
Author(s):  
Claudio Napolis Costa ◽  
Claudio Manoel Rodrigues de Melo ◽  
Irineu Umberto Packer ◽  
Ary Ferreira de Freitas ◽  
Nilson Milagres Teixeira ◽  
...  
Keyword(s):  
Variance Components ◽  
Legendre Polynomials ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Holstein Cows ◽  
Residual Variance ◽  
Environmental Variance ◽  
Environmental Correlations ◽  
Lp Estimates

Data comprising 263,390 test-day (TD) records of 32,448 first parity cows calving in 467 herds between 1991 and 2001 from the Brazilian Holstein Association were used to estimate genetic and permanent environmental variance components in a random regression animal model using Legendre polynomials (LP) of order three to five by REML. Residual variance was assumed to be constant in all or in some classes of lactation periods for each LP. Estimates of genetic and permanent environmental variances did not show any trend due to the increase in the LP order. Residual variance decreased as the order of LP increased when it was assumed constant, and it was highest at the beginning of lactation and relatively constant in mid lactation when assumed to vary between classes. The range for the estimates of heritability (0.27 - 0.42) was similar for all models and was higher in mid lactation. There were only slight differences between the models in both genetic and permanent environmental correlations. Genetic correlations decreased for near unity between adjacent days to values as low as 0.24 between early and late lactation. A five parameter LP to model both genetic and permanent environmental effects and assuming a homogeneous residual variance would be a parsimonious option to fit TD yields of Holstein cows in Brazil.

Effect of milk fat to protein ratio on genetic variance for milk yield in Thai tropical Holstein cattle

2016 ◽  
Vol 96 (3) ◽  
pp. 410-415 ◽  
Author(s):  
S. Puangdee ◽  
M. Duangjinda ◽  
W. Boonkum ◽  
S. Buaban ◽  
S. Katawatin
Keyword(s):  
Milk Fat ◽  
Variance Components ◽  
Legendre Polynomials ◽  
Bayesian Method ◽  
Genetic Variance ◽  
Genetic Correlations ◽  
Random Regression ◽  
Third Order ◽  
Protein Ratio ◽  
Regression Test

The objective of this research was to investigate the optimum fat to protein ratio (FPR) in Thai tropical Holstein dairy cattle. First parity data consisting of 20 492 milk yields (MY) records for 24 891 cows for the period 2001 and 2011, were used in the analysis. The analysis used a random regression test-day animal model of third-order Legendre polynomials through the creation of a covariance function based on different FPRs. Variance components were estimated using the Bayesian method via the Gibbs sampling. The estimated heritability of MY in relation to FPR ranged from 0.19 to 0.27 with the pattern being similar to the genetic variances. Genetic correlations of MY at different FPRs were high at consecutive FPRs and then declined to negative in response to greater differences in FPR. Based on the results, it is concluded that the optimum FPR is in the range of 0.9 to 1.9, corresponding to the genetically controlled energy balance for MY in tropical Holsteins.

scholarly journals Modeling of average growth curve in Santa Ines sheep using random regression models

2011 ◽  
Vol 40 (2) ◽  
pp. 314-322 ◽  
Author(s):  
José Lindenberg Rocha Sarmento ◽  
Robledo de Almeida Torres ◽  
Wandrick Hauss de Sousa ◽  
Lucia Galvão de Albuquerque ◽  
Raimundo Nonato Braga Lôbo ◽  
...  
Keyword(s):  
Growth Curve ◽  
Regression Models ◽  
Random Regression ◽  
Average Growth ◽  
Breeding Values ◽  
Cubic Polynomial ◽  
Linear Fit ◽  
Santa Inês ◽  
The Difference ◽  
Cubic Function

Polynomial functions of age of different orders were evaluated in the modeling of the average growth trajectory in Santa Ines sheep in random regression models. Initially, the analyses were performed not considering the animal effect. Subsequently, the random regression analyses were performed including the random effects of the animal and its mother (genetic and permanent environment). The linear fit was lower, and the other orders were similar until near 100 days of age. The cubic function provided the closest fit of the observed averages, mainly at the end of the curve. Orders superior to this one tended to present incoherent behavior with the observed weights. The estimated direct heritabilities, considering the linear fit, were higher to those estimated by considering other functions. The changes in animal ranking based on predicted breeding values using linear fit and superior orders were small; however, the difference in magnitude of the predicted breeding values was higher, reaching values 77% higher than those obtained with the cubic function. The cubic polynomial function is efficient in describing the average growth curve.

scholarly journals Genetic evaluation of partial growth trajectory of Santa Inês breed using random regression models

2010 ◽  
Vol 39 (5) ◽  
pp. 1029-1036 ◽  
Author(s):  
Kassiana Adriano Pinto de Oliveira ◽  
Raimundo Nonato Braga Lôbo ◽  
Olivardo Facó
Keyword(s):  
Legendre Polynomials ◽  
Fixed Effects ◽  
Genetic Correlations ◽  
Growth Trajectory ◽  
Random Regression ◽  
Data Set ◽  
Average Growth ◽  
Santa Inês ◽  
Group Sex ◽  
Different Order

It was evaluated data set of 19,303 weight records of Santa Inês sheep in order to evaluate distinct polynomial functions with different order for better adjustements of fixed and random regressions of growth trajectory and to estimate (co)variances components and genetic parameters of this trajectory. Fixed effects used in analysis were contemporary group, sex and birth type. Ordinary and Legendre polynomials, ranging from two to four orders, were evaluated for fixed regression of average growth trajectory. Legendre and quadratic b-spline functions, ranging from three to four orders, were evaluated for random regressions. Legendre polynomials of order fourth were suitable to fit random regression, while ordinary polynomials of third order were the best for fixed trajectory. Direct heritabilities on days 1, 50, 150, 250 and 411 were 0.24, 0.12, 0.44, 0.84, and 0.96, respectively, while maternal heritabilities for the same ages were 0.24, 0.19, 0.09, 0.02, and 0.01, respectively. Genetic correlations among weights in subsequent ages were high, tending to unity, and there were negative correlations between weights at early ages and weights at late ages. It is possible to modify the growth trajectory by selection with the observed genetic variability. Genetic control of weights at initial ages is not the same in late ages. So, selection of animals for slaughter in early age must be different from that of replacement animals.

scholarly journals Covariance functions under B-spline polynomials to model Polled Nellore cattle growth

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3977-3990
Author(s):  
Diego Helcias Cavalcante ◽  
◽  
Carlos Syllas Monteiro Luz ◽  
Marcelo Richelly Alves de Oliveira ◽  
Wéverton José Lima Fonseca ◽  
...  
Keyword(s):  
Random Effects ◽  
Growth Curve ◽  
Fixed Effects ◽  
Random Regression ◽  
Spline Functions ◽  
Average Growth ◽  
B Spline ◽  
Covariance Functions ◽  
Model Animal ◽  
Nellore Cattle

B-spline functions have been used in random regression models (RRM) to model animal weight from birth to adulthood because they are less vulnerable to common difficulties of other methods. However, its application to model growth traits of Polled Nellore cattle has been little studied. Therefore, this study aimed to evaluate polynomial functions of different orders and segment numbers to model effects associated with the Polled Nellore cattle growth curve. For this purpose, we used 15,148 weight records of 3,115 animals aged between 1 and 660 days and reared in northern Brazil and born between 1995 and 2010. Random effects were modeled using B-spline polynomials. As random effects, we considered the direct and maternal genetic additives, as well as direct and maternal permanent environments. As fixed effects were included contemporary group, cow age at calving (linear and quadratic) and fourth-order Legendre polynomials to represent average growth curve. The residue was modeled by considering seven age classes. The bestfitted model was the one that considered cubic B-spline functions with four knots for direct additive genetic effects and three knots for maternal genetic, animal permanent environment, and maternal permanent environment effects (C6555). Therefore, covariance functions under B-spline polynomials are efficient and can be used to model the growth curve of Polled Nellore cattle from birth to 660 days of age.

Selection in pigs for increased lean growth rate on a time-based feeding scale

1988 ◽  
Vol 47 (1) ◽  
pp. 149-156 ◽  
Author(s):  
C. P. McPhee ◽  
G. A. Rathmell ◽  
L. J. Daniels ◽  
N. D. Cameron
Keyword(s):  
Growth Rate ◽  
Variance Components ◽  
Performance Test ◽  
Selection Criterion ◽  
Live Weight ◽  
Control Line ◽  
Lean Tissue ◽  
Lean Growth ◽  
Ad Libitum ◽  
And Control

AbstractSelection was carried out in a line of pigs for increased growth rate of lean tissue. The selection criterion was weight of lean in the ham predicted from live backfat and weight measurements after a 12-week performance test commencing at 25 kg live weight. All pigs were given the same total amount of food over the test period. The scale was set to about proportionately 0·85 of predicted ad libitum intake. Boars selected with an intensity of 1/12 were used for 6 months and sows selected with an intensity of 1/4 were kept for two farrowings. An unselected control line was maintained concurrently.After five generations, performances of selected and control line pigs were compared on ad libitum and scale feeding as they grew to 85 kg. Responses in the selected line on scale feeding were +51 g/day for growth rate (GR), −0·16 for food conversion ratio (FCR), −2·2 mm for backfat (F) and +0·47 kg for ham lean (HL). On ad libitum feeding, responses were much higher in the selected line, giving rise to line × food interactions. Responses were +128 g/day for GR, −0·27 for FCR, −2·3 mm for F, +1·01 kg for HL and +0·15 kg/day for food intake (FI). Estimates of the heritability of HL from variance components were 0·43 (s.e. 0·15) on scale feeding and 0·28 (s.e. 0·19) on ad libitum feeding. The realized heritability of HL on scale feeding was 0·29 (s.e. 0·04) and its co-heritabilities with the other traits on both feeding levels were of similar magnitude to its heritability. Scale feeding exposed genetic variation in the partitioning of food between lean and fat deposition and appeared to be a suitable selection regimen for performance on ad libitum feeding.

scholarly journals Effect of boars own performance on progeny fattening and carcass traits in two different environments

2004 ◽  
Vol 20 (3-4) ◽  
pp. 55-63 ◽  
Author(s):  
I. Bahelka ◽  
P. Fľak ◽  
Anna Lukácová
Keyword(s):  
Performance Test ◽  
Average Daily Gain ◽  
Carcass Traits ◽  
Live Weight ◽  
Feed Consumption ◽  
Muscle Area ◽  
Eye Muscle ◽  
Carcass Parameters ◽  
Performance Traits ◽  
Progeny Performance

The effect of own performance traits of meat breed boars on fattening and carcass parameters of progeny in two different test stations (Bucany and Nitra) was evaluated. Own performance traits of boars were average daily gain (ADG) from birth to 100 kg live weight, backfat thickness (BF) and lean meat content (LMC) in field conditions. Progeny of boars was housed in pairs (gilt and barrow) and fed standardized feed mixture semi ad libitum. Progeny test lasted from 30 to 100 kg live weight. There were evaluated following parameters: ADG and feed consumption/kg gain (FC) at test from 30 to 100 kg live weight, slaughter weight (SW), proportion of meaty cuts (PMC) proportion of ham (PHAM), eye muscle area (EMA), and BF. At Bucany and Nitra was found the effect of genotype of boars on progeny BF and/or FC respectively. Better tested boars from own performance test individually as well as a group achieved in progeny better fattening and carcass traits than worse tested boars at Bucany (+33 g ADG, -0.21 cm BF, +2.34 % PMC). Progeny performance from better evaluated boars at Nitra did not exceed the progeny performance from worse tested boars. There was found significant effect of dams on progeny performance.

scholarly journals Influence guanidinoacetic acid on the growth of young animals quails meat direction of productivity

2016 ◽  
Vol 18 (2) ◽  
Author(s):  
M. Sychov ◽  
H. Pryumak
Keyword(s):  
Average Daily Gain ◽  
Live Weight ◽  
Control Group ◽  
Average Growth ◽  
Absolute Increase ◽  
Relative Growth ◽  
Guanidinoacetic Acid ◽  
Relative Gains ◽  
Daily Gain ◽  
Different Levels

The effect of using different levels guanidinoacetic acid in compound feeds on the growth of young quails meat direction of productivity. It is proved that adding to the basic diet of different levels guanidinoacetic acid (0.06, 0.12, 0.18 %) increases live weight of quails on 3.9 – 13.5 g and improves the absolute, average daily and relative gains compared to a bird in the control group, which were fed the main diet. The data show that at the age of 42 days of live weight was the highest in the diet of quail which was administered 0.12% GAA and dominant control of 13.5 g However, in 21 days live weight of quail fed 0.06 and 0.12 % guanidinoacetic acid was greater than control respectively 9.2 and 7.6 grams (P < 0.01). In absolute increments quail, fed GAA prevailed bird control group. The largest absolute increase was in birds that consumed the main diet of GAA level of 0.12% and prevailed controls 6.5 g (P < 0.001). A similar situation was of average daily gain. Young animals that received feed containing 0.12% guanidinoacetic acid had the highest average growth, which exceeded 0.9 g (15.5%) bird control group. As for the relative performance increases here were different. The lowest relative growth observed in birds which were administered GAA 0.06%, it lagged behind the controls 0.1 g in the same period quail treated with 0.12 and 0, 18% guanidinoacetic acid superior control respectively 2 and 1.1 g.

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