scholarly journals Influence of rearing system on growth of bulls in performance test

2002 ◽  
Vol 18 (1-2) ◽  
pp. 3-10
Author(s):  
Vladan Bogdanovic ◽  
Milan Petrovic
Keyword(s):  
Performance Test ◽  
Growth Traits ◽  
Statistical Significance ◽  
Average Daily Gain ◽  
Test System ◽  
Two Factors ◽  
Origin Group ◽  
Sources Of Variation ◽  
Beef Bulls

Data on 643 beef bulls were used in order to analyze influence of rearing system or herd of origin on growth traits (average daily gain and body masses) of beef bulls in performance test (Marchigiana, n= 181, Chianina, n=240, Romagnola, n=222). Several fixed or random effects, such as breed, type of rearing or herd of origin, group, parity and twinning, were included in two statistical models. According to rearing system (in stall, on pasture or mixed) it should be pointed out that several different sources of variation for growth traits evince statistical significance. Also, herd of origin represents very significant source of variation for all included traits. The main difference between those two factors (type of rearing system or herd of origin) is that influence of rearing system decreased during the test, while the effect of herd of origin remained until the end of test. It was concluded that the adequate determination of non-genetic sources of variation referring to the pre-test system of rearing might be of crucial importance for ranking potential sires.

scholarly journals Sources of variability of growth and body development traits of Simmental bulls in performance test

2015 ◽  
Vol 31 (3) ◽  
pp. 339-348
Author(s):  
M. Lazarevic ◽  
D. Niksic ◽  
V. Pantelic ◽  
N. Stanisic ◽  
N. Delic ◽  
...  
Keyword(s):  
Body Mass ◽  
Performance Test ◽  
Growth Traits ◽  
Statistical Significance ◽  
Average Daily Gain ◽  
Analysis Data ◽  
The Body ◽  
Body Development ◽  
High Level ◽  
Daily Gain

To test the variability of traits of Simmental bulls in performance test, data of the Livestock - Veterinary Centres for Reproduction and Artificial Insemination of Velika Plana and Krnjaca were used. In the analysis, data on 113 performance tested bulls born from 2008 to 2009 were used. The analysis included two sets of characteristics: body development traits and growth traits. The average body mass of calves entering the test was 195.75 kg, while the body mass at the end of the test was 476.50 kg, average daily gain in the test was 1138.69 g. Average values of body development traits measured at the end of the test, with 12 months of age were: height at withers 127.13 cm, chest circumference 179.42 cm, the chest depth 61.19 cm and body length 151.34 cm. The influence of their sires, the year and the Centre on the variability of traits was studied. The effect of age is present at a high level of statistical significance (p<0.01) for all traits that are registered at the end of the test, while the effect of the Centre was present in the variability of body mass at the end of the test, the daily gain in the test and the length of the body. The bulls-sires' influence was demonstrated (p<0.05) on the variability in body mass of calves entering the test.

scholarly journals Effectiveness of Genetic Parameter Estimation in a Small Flock of Merino Sheep with Shallow Pedigree

2020 ◽  
Vol 8 (4) ◽  
pp. 920-926
Author(s):  
Serdar Duru ◽  
Mehmet Koyuncu
Keyword(s):  
Growth Traits ◽  
Genetic Parameter ◽  
Average Daily Gain ◽  
Information Criterion ◽  
Suitable Model ◽  
Merino Sheep ◽  
Kleiber Ratio ◽  
Sources Of Variation ◽  
Maternal Heritability ◽  
Daily Gain

In this study, the genetic and non-genetic parameters were estimated for growth traits of Karacabey merino sheep. Growth performance data refer to 1863 lambs born between 2016 and 2018. Analyses were carried out by restricted maximum likelihood fitting animal models and disregarding or including maternal genetic or maternal permanent environmental effect. Six different animal model were fitted for all traits, and the most suitable model for each trait was chosen after Akaike information criterion test (AIC). Year of birth, age of dam, type of birth and lamb sex were significant sources of variation on birth weight (BW), average daily gain (ADG), Kleiber ratio (KR), weaning weight (WW) and six month weight (6MW). Direct heritability (h^2) for BW, ADG and 6MW were 0.12, 0.02 and 0.04, respectively, however, for KR and WW were 0.00 model 6 (which the best). The estimates of maternal heritability (m^2) for ADG, KR and WW were 0.12, 0.04 and 0.04, respectively in model 5, also maternal heritability were low for BW and 6MW. Maternal permanent environmental effects (c^2) have high contribution to the explanation growth traits and were estimated between 0.19 and 0.75 for these traits. These results showed that selecting for improved maternal and/or direct effects for Karacabey merino in the herd would generate very slow genetic improvement in growth traits.

scholarly journals Source of variation and heritability of directly measured traits in performance testing of Simmental bulls

Genetika ◽  
2012 ◽  
Vol 44 (1) ◽  
pp. 153-162
Author(s):  
Vladan Bogdanovic
Keyword(s):  
Performance Test ◽  
Growth Traits ◽  
Statistical Significance ◽  
Performance Testing ◽  
Test Group ◽  
The Body ◽  
Components Of Variance ◽  
Body Development ◽  
Heritability Estimates ◽  
Almost All

In order to study the variability and heritability of directly measured traits (growth and body development traits) in performance test of Simmental bulls the data on 371 bulls born and tested over the period of 13 years were used in the analysis. The data were analyzed in order to estimate year and month of calving, herd of origin and group in test effect as well as error components. The components of variance were obtained using restricted maximum likelihood (REML) methodology applied to sire model. The year and month of birth had different effect on the variability of the growth traits, while the herd of origin and the test group manifested a consistent, highly significant effect on those growth traits which they could have an effect on. On the other hand, all the body development traits were under a constant and highly significant effect manifested by the year of calving, while the month of calving manifested its effect, during test, at different levels of statistical significance. A decreased effect of herd of origin on almost all body dimensions from the start until the end of performance test was universally observed. Heritability estimates for pre-test ADG, in-test and lifetime ADG were 0.27, 0.39 and 0.29, respectively. Heritability estimates for body weights were 0.23, 0.25, and 0.30 for birth weight, test-on weight, and test-off weight, respectively. Heritability estimates for test-off height at withers, circumference of chest, depth of chest and body length were 0.43, 0.30, 0.33 and 0.29.

GENOTYPE × ENVIRONMENT INTERACTIONS FOR POSTWEANING GROWTH PERFORMANCE OF BACKCROSS BULLS

1987 ◽  
Vol 67 (2) ◽  
pp. 359-370 ◽  
Author(s):  
G. W. RAHNEFELD ◽  
R. M. McKAY ◽  
H. T. FREDEEN ◽  
G. M. WEISS ◽  
J. A. NEWMAN ◽  
...  
Keyword(s):  
Growth Rates ◽  
Fixed Effects ◽  
Performance Test ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Environment Interaction ◽  
Test Results ◽  
Ge Interaction ◽  
Genotype Environment Interaction ◽  
Daily Gain

The effects of pretest and genotype × environment (GE) interactions of 137 reciprocal backcross bulls produced under two contrasting environments (Brandon, Manitoba and Manyberries, Alberta) were evaluated for postweaning performance traits. Differences in weaning weight and average daily gain during the pretest periods defined as preweaning (ADGBW), weaning to on-test (ADGWT), and birth to on-test (ADGBT) associated with the fixed effects of station of origin, breed cross and station of origin by test were not significant. Station of test effects were significant (P = 0.0001) for ADGWT and ADGBT. None of the GE interactions involving the station of origin was significant (P > 0.10) for the postweaning growth traits and probabilities exceeded 0.20 for all but three of the 40 traits. The GE interactions involving station of test were nonsignificant (P > 0.20) for all but eight traits. All of these exceptions involved the cumulative average daily gain in the eight periods which excluded the first 14 d of test. Although the GE interaction for average daily gain for 140 d of test was not significant there were substantial breed cross differences in growth rates at the two test locations. Users of performance test results, however, are generally concerned with absolute performance values, not statistically significant differences. Viewed in this context, the differential responses of genotypes under different test environments, even though statistically nonsignificant, could have important implications to the industry. Key words: Cattle, postweaning growth, genotype × environment interaction

HERITABILITY OF SCROTAL CIRCUMFERENCE IN ONE- AND TWO-YEAR-OLD BULLS OF DIFFERENT BEEF BREEDS

1987 ◽  
Vol 67 (3) ◽  
pp. 645-651 ◽  
Author(s):  
G. H. COULTER ◽  
G. C. KOZUB ◽  
D. R. C. BAILEY ◽  
R. J. MAPLETOFT ◽  
W. F. CATES
Keyword(s):  
Statistical Model ◽  
Key Words ◽  
Fixed Effects ◽  
Performance Test ◽  
Age Groups ◽  
Scrotal Circumference ◽  
Sources Of Variation ◽  
Testicular Size ◽  
Heritability Estimates ◽  
Beef Bulls

Over an 8-yr interval, (1975–1982) scrotal circumference (SC) was measured on 4557 1-yr-old beef bulls from 1796 sires and eight breeds. Measurements were taken upon completion of a 140-d growth performance test. During the period 1977–1983, SC was measured on 7835 2-yr-old beef bulls from 2570 sires and six breeds. Two-year-old bulls were measured during reproductive examinations at spring bull sales. All SC measurements were adjusted for fixed effects of location-year and age, and heritability estimates were calculated within-breed using a paternal half-sib analysis. Heritability estimates for the SC trait in Angus, Charolais, horned Hereford, polled Hereford, Shorthorn, Simmental, Limousin and Maine-Anjou breeds in 1-yr-old bulls were 0.22 ± 0.20, 0.46 ± 0.14, 0.89 ± 0.17, 0.83 ± 0.26, 1.01 ± 0.31, 0.63 ± 0.19, 0.94 ± 0.29 and 0.59 ± 0.22. Heritability estimates for SC in 2-yr-old bulls of the first six breeds were 0.00 ± 0.21, 0.60 ± 0.25, 0.57 ± 0.07, 0.65 ± 0.10, 0.69 ± 0.34 and 0.20 ± 0.24. Owing to the small number of sires or sons within sires for some breed-age groups and the exclusion of some sources of variation in the statistical model, the estimates of heritability may not be precise and should be used to indicate approximate levels of heritability for a particular breed. Key words: Heritability, testicular size, scrotal circumference, beef bulls

A comparison of production traits and welfare implications between horned and polled beef bulls

1996 ◽  
Vol 76 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. M. Stookey ◽  
L. A. Goonewardene
Keyword(s):  
Key Words ◽  
Performance Test ◽  
Average Daily Gain ◽  
Production Traits ◽  
Scrotal Circumference ◽  
Welfare Implications ◽  
Beef Bulls ◽  
Selected Traits ◽  
The University ◽  
Daily Gain

Data from two record of performance test stations (ROP) were used to compare selected traits of polled and horned bulls. The University of Saskatchewan (SASK) ROP test station provided data on 578 Charolais (CH) and 375 Hereford (HE) bulls from 1985 to 1992, while the Alberta (ALTA) Hereford ROP station provided data on 1485 HE bulls from 1985 to 1993. Polled and horned CH bulls from SASK showed similar (P > 0.05) on-test average daily gain (ADG), while polled HE bulls from SASK showed significantly higher (P < 0.03) ADG than their horned counterparts (1.41 ± 0.01 and 1.36 ± 0.02, respectively). Polled CH bulls were 11.4% fatter than horned bulls at the end of the test (P < 0.01). No significant differences in ADG, weight per day of age (WPDA) or scrotal circumference (SC) were observed between polled and homed HE bulls in ALTA. These results show no disadvantage for polled bulls compared to horned for ADG, WPDA, adjusted SC and adjusted yearling weight. From a welfare perspective, it may be advantageous to use polled bulls to circumvent the need for dehorning. Key words: Polled horned bulls ADG test station

scholarly journals Research on Performance Test System of Space Harmonic Reducer in High Vacuum and Low Temperature Environment

Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Performance Test ◽  
High Reliability ◽  
High Vacuum ◽  
Test System ◽  
Low Noise ◽  
Speed Ratio ◽  
Space Harmonic ◽  
Temperature Environment

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.

scholarly journals Grid search approach to discriminate between old and recent inbreeding using phenotypic, pedigree and genomic information

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Pattarapol Sumreddee ◽  
El Hamidi Hay ◽  
Sajjad Toghiani ◽  
Andrew Roberts ◽  
Samuel E. Aggrey ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Recent Common Ancestor ◽  
Pedigree Information ◽  
Grid Search ◽  
Genomic Information ◽  
The Impact ◽  
Daily Gain ◽  
Harmful Effects

Abstract Background Although inbreeding caused by the mating of animals related through a recent common ancestor is expected to have more harmful effects on phenotypes than ancient inbreeding (old inbreeding), estimating these effects requires a clear definition of recent (new) and ancient (old) inbreeding. Several methods have been proposed to classify inbreeding using pedigree and genomic data. Unfortunately, these methods are largely based on heuristic criteria such as the number of generations from a common ancestor or length of runs of homozygosity (ROH) segments. To mitigate these deficiencies, this study aimed to develop a method to classify pedigree and genomic inbreeding into recent and ancient classes based on a grid search algorithm driven by the assumption that new inbreeding tends to have a more pronounced detrimental effect on traits. The proposed method was tested using a cattle population characterized by a deep pedigree. Results Effects of recent and ancient inbreeding were assessed on four growth traits (birth, weaning and yearling weights and average daily gain). Thresholds to classify inbreeding into recent and ancient classes were trait-specific and varied across traits and sources of information. Using pedigree information, inbreeding generated in the last 10 to 11 generations was considered as recent. When genomic information (ROH) was used, thresholds ranged between four to seven generations, indicating, in part, the ability of ROH segments to characterize the harmful effects of inbreeding in shorter periods of time. Nevertheless, using the proposed classification method, the discrimination between new and old inbreeding was less robust when ROH segments were used compared to pedigree. Using several model comparison criteria, the proposed approach was generally better than existing methods. Recent inbreeding appeared to be more harmful across the growth traits analyzed. However, both new and old inbreeding were found to be associated with decreased yearling weight and average daily gain. Conclusions The proposed method provided a more objective quantitative approach for the classification of inbreeding. The proposed method detected a clear divergence in the effects of old and recent inbreeding using pedigree data and it was superior to existing methods for all analyzed traits. Using ROH data, the discrimination between old and recent inbreeding was less clear and the proposed method was superior to existing approaches for two out of the four analyzed traits. Deleterious effects of recent inbreeding were detected sooner (fewer generations) using genomic information than pedigree. Difference in the results using genomic and pedigree information could be due to the dissimilarity in the number of generations to a common ancestor. Additionally, the uncertainty associated with the identification of ROH segments and associated inbreeding could have an effect on the results. Potential biases in the estimation of inbreeding effects may occur when new and old inbreeding are discriminated based on arbitrary thresholds. To minimize the impact of inbreeding, mating designs should take the different inbreeding origins into consideration.

scholarly journals HRV analysis: undependability of approximate entropy at locating optimum complexity in malnourished children

2021 ◽  
pp. 1-6
Author(s):  
David M. Garner ◽  
Gláucia S. Barreto ◽  
Vitor E. Valenti ◽  
Franciele M. Vanderlei ◽  
Andrey A. Porto ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Accurate Determination ◽  
Approximate Entropy ◽  
Effect Sizes ◽  
Potential Hazard ◽  
Autonomic Modulation ◽  
Embedding Dimension ◽  
Malnourished Children ◽  
Hrv Analysis

Abstract Introduction: Approximate Entropy is an extensively enforced metric to evaluate chaotic responses and irregularities of RR intervals sourced from an eletrocardiogram. However, to estimate their responses, it has one major problem – the accurate determination of tolerances and embedding dimensions. So, we aimed to overt this potential hazard by calculating numerous alternatives to detect their optimality in malnourished children. Materials and methods: We evaluated 70 subjects split equally: malnourished children and controls. To estimate autonomic modulation, the heart rate was measured lacking any physical, sensory or pharmacologic stimuli. In the time series attained, Approximate Entropy was computed for tolerance (0.1→0.5 in intervals of 0.1) and embedding dimension (1→5 in intervals of 1) and the statistical significances between the groups by their Cohen’s ds and Hedges’s gs were totalled. Results: The uppermost value of statistical significance accomplished for the effect sizes for any of the combinations was −0.2897 (Cohen’s ds) and −0.2865 (Hedges’s gs). This was achieved with embedding dimension = 5 and tolerance = 0.3. Conclusions: Approximate Entropy was able to identify a reduction in chaotic response via malnourished children. The best values of embedding dimension and tolerance of the Approximate Entropy to identify malnourished children were, respectively, embedding dimension = 5 and embedding tolerance = 0.3. Nevertheless, Approximate Entropy is still an unreliable mathematical marker to regulate this.

Sign in / Sign up

Export Citation Format

Share Document