An analysis of the variation in the lean tissue distribution of sheep

1982 ◽  
Vol 34 (3) ◽  
pp. 257-264 ◽  
Author(s):  
B. T. Wolf
Keyword(s):  
Tissue Distribution ◽  
Genetic Correlation ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Maximum Difference ◽  
Lean Tissue ◽  
Heritability Estimates ◽  
The Relationship ◽  
Daily Gain ◽  
Sire Breed

ABSTRACTThe distribution of lean tissue between eight standard joints was examined in 956 crossbred lambs slaughtered at constant live weights of either 35 or 40 kg. The sire breeds used were the Dorset Down, Ile-de-France, Oldenburg, Oxford, Suffolk and Texel. Sire breed did not have a significant effect on the proportion of total carcass lean found in the higher-priced joints but did show significant differences in the proportion of total carcass lean found in individual joints, with a maximum difference of 7·7 g total lean per kg joint being recorded. Similarly, small but significant effects due to ewe age (1 to 3 years), rearing type (single, twin, triplet), sex (male castrate, female) and weight of total lean were reported for the proportion of total carcass lean found in different joints.Heritability estimates ranged from 0·07 (s.e. 008) to 0·65 (s.e. 0·16) for the proportion of total lean in the best-end neck and higher-priced joints respectively. Phenotypic standard deviations of 5·8g/kg and 17·9g/kg were reported for the proportion of total lean found in the best-end neck and the higher-priced joints respectively. The genetic correlations between the proportion of total lean in each of the higher-priced joints and the proportion of total lean in the higher-priced joints combined were positive. A genetic correlation of 017 (s.e. 0·20) was found for the relationship between average daily gain from birth to slaughter and the proportion of total lean in the higher-priced joints.

HERITABILITIES AND GENETIC CORRELATIONS FOR ULTRASONIC BACKFAT MEASUREMENTS, GROWTH AND CARCASS TRAITS IN SWINE

1982 ◽  
Vol 62 (3) ◽  
pp. 665-670 ◽  
Author(s):  
D. C. JEFFRIES ◽  
R. G. PETERSON
Keyword(s):  
Key Words ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Ultrasonic Measurements ◽  
Yorkshire Pigs ◽  
Daily Gain ◽  
Season Interaction

Genetic parameters were estimated for 2403 purebred Yorkshire pigs over a 2-yr period, representing 21 sires. The traits studied included average daily gain, age adjusted to 90 kg, ultrasonic measurements of backfat at the mid-back and loin positions, total and adjusted total ultrasonic backfat and corresponding carcass backfat measurements. Least squares analyses were used to estimate and adjust for the effects of sex, year-season and sex by year-season interaction. Heritabilities and genetic correlations were calculated for all traits using both half- and full-sib estimates. Adjusted age and adjusted total ultrasonic backfat measurements were found to have the highest heritabilities of the live traits in this study. Estimates of heritability for adjusted age and adjusted total ultrasonic backfat were 0.24 ± 0.10 and 0.26 ± 0.10 based on half-sib and 0.56 ± 0.07 and 0.41 ± 0.06 from full-sib analyses. The genetic correlation between these two traits was −0.07 ± 0.28 based on the half-sib method. The total phenotypic correlation was −0.01 ± 0.02. Key words: Swine, ultrasonic backfat, heritabilities, genetic correlations

scholarly journals 209 Genomic selection for multiple maternal and growth traits in large white pigs using Single-Step GBLUP

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 42-42
Author(s):  
Breno Fragomeni ◽  
Zulma Vitezica ◽  
Justine Liu ◽  
Yijian Huang ◽  
Kent Gray ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Growth Traits ◽  
Computing Time ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Single Step ◽  
Genomic Information ◽  
Genomic Evaluation ◽  
Large White ◽  
Daily Gain

Abstract The objective of this study was to implement a multi-trait genomic evaluation for maternal and growth traits in a swine population. Phenotypes for preweaning mortality, litter size, weaning weight, and average daily gain were available for 282K Large White pigs. The pedigree included 314k individuals, of which 35,731 were genotyped for 45K SNPs. Variance components were estimated in a multi-trait animal model without genomic information by AIREMLF90. Genomic breeding values were estimated using the genomic information by single-step GBLUP. The algorithm for proven and young (APY) was used to reduce computing time. Genetic correlation between proportion and the total number of preweaning deaths was 0.95. A strong, positive genetic correlation was also observed between weaning weight and average daily gain (r = 0.94). Conversely, the genetic correlations between mortality and growth traits were negative, with an average of -0.7. To avoid computations by expensive threshold models, preweaning mortality was transformed from a binary trait to two linear dam traits: proportion and a total number of piglets dead before weaning. Because of the high genetic correlations within groups of traits, inclusion of only one growth and one mortality trait in the model decreases computing time and allows for the inclusion of other traits. Reduction in computing time for the evaluation using APY was up to 20x, and no differences in EPD ranking were observed. The algorithm for proven and young improves the efficiency of genomic evaluation in swine without harming the quality of predictions. For this population, a binary trait of mortality can be replaced by a linear trait of the dam, resulting in a similar ranking for the selection candidates.

Effects of dietary energy planes on growth and heritability estimates for postweaning growth traits in young beef bulls

1995 ◽  
Vol 75 (3) ◽  
pp. 469-472
Author(s):  
D. R. C. Bailey ◽  
M. F. Liu ◽  
N. H. Shannon
Keyword(s):  
Growth Rate ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Dietary Energy ◽  
Relative Growth ◽  
Heritability Estimates ◽  
Energy Plane ◽  
Maternal Heritability ◽  
Daily Gain

Records of young AN and young HE bulls were analyzed to evaluate the influences of dietary energy planes on growth and heritability estimates of growth traits during 168-d postweaning test. Estimates of h2a for end of test weight (WT168), average daily gain on test (ADG 0–168) and relative growth rate on test (RGR 0–168) were much higher in the MED line than in the HED line. Between lines, maternal heritability estimates (h2m) for WT0 and ADG 0–168 were similar. Estimates of h2m for WT168 was much higher in the HED line than in the MED line. All direct-maternal genetic correlations (ram) were negative. These results may indicate that the antagonism between direct and maternal genetic effects for postweaning growth traits in the MED line was much less than that in the HED line. Key words: Beef cattle, energy plane, growth, heritability

scholarly journals Realized Sampling Variances of Estimates of Genetic Parameters and the Difference Between Genetic and Phenotypic Correlations

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Phenotypic Correlation ◽  
Parameter Estimates ◽  
Sampling Variance ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.

Flight speed as an indicator of Zebu cattle growth performance and suitability to the feedlot environment

2020 ◽  
Vol 60 (4) ◽  
pp. 560
Author(s):  
Désirée Gellatly ◽  
Joslaine N. S. G. Cyrillo ◽  
Aline C. Sant'Anna ◽  
Tiago S. Valente ◽  
Karen Schwartzkopf-Genswein ◽  
...  
Keyword(s):  
Growth Performance ◽  
Bos Taurus ◽  
Average Daily Gain ◽  
Flight Speed ◽  
Zebu Cattle ◽  
Feedlot Performance ◽  
Unit Increase ◽  
The Relationship ◽  
Daily Gain ◽  
Over Time

Context Studies assessing the relationship between cattle reactivity and growth performance, as well as suitability to the feedlot, in Zebu cattle are limited. Based on previous studies using Bos Taurus cattle, it is expected that reactivity measured at weaning could be used as a predictor of feedlot performance, and that cattle with greater flight speed (FS) would have reduced average daily gain (ADG). Aims The aims of this study were to (1) determine if FS (m/s) measured before entry into the feedlot could be used as a predictor of cattle performance, (2) evaluate the consistency of FS over time, and (3) determine when FS should be measured to best predict animal suitability to the feedlot. Methods A total of 54 Nellore and 40 Guzerat calves were assessed by using FS, which was collected at the time of (FS0) and 1 week after weaning (FS1), as well as on Day 28 (FS28), 56 (FS56) and 168 (FS168) after entry into the feedlot, and a FS average was calculated using FS28, FS56 and FS168 (FS28–168). Performance using ADG (kg/calf.day) was calculated for each animal over three periods: ADG1–28, ADG28–168 and ADG1–168. Bunk attendance (min/calf.day) was recorded over a 173-day feeding period. Key results The ADG28–168 was reduced by 0.14 kg/calf.day for each unit increase in FS0 (P < 0.05). Both ADG28–168 and ADG1–168 were reduced by 0.02 kg/calf.day for each unit increase in FS1 (P ≤ 0.01), but neither FS0 nor FS1 was associated with ADG1–28 (P > 0.10). A significant increase was observed between FS1 and FS28 (P < 0.01), followed by a reduction in FS56 (P < 0.01) and FS168 (P < 0.01). Conclusion FS measured at or within 1 week of weaning has the potential to be used as an indicator of feedlot growth performance in Nellore and Guzerat cattle. Implications Although our results do not indicate the efficacy of FS as a predictor of early suitability of cattle to the feedlot, it does have the potential to support its recommendation as an indicator of overall feedlot growth performance in Nellore and Guzerat breeds.

Genetic parameters for growth rate and Kleiber ratios of Nellore sheep

2018 ◽  
Author(s):  
I. Satish Kumar ◽  
G. Gangaraju ◽  
C. Vijaya Kumar ◽  
Sapna Nath
Keyword(s):  
Andhra Pradesh ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Research Station ◽  
Genetic Progress ◽  
Stages Of Growth ◽  
Kleiber Ratio ◽  
Nellore Sheep ◽  
Daily Gain

Data on growth traits of Nellore sheep were extracted from the records maintained at Livestock Research Station, Palamaner, Andhra Pradesh, India for a period of five years. The genetic and phenotypic parameters were estimated for growth traits i.e., average daily gain (ADG) from birth to 3 months (ADGa), 3 months to 6 months (ADGb), 6 to 12 months (ADGc) and the corresponding Kleiber ratio (KR) at respective stages of growth. The non genetic factors included in the model were having significance on most of the traits studied. The heritability estimates for ADG and corresponding KR ranged from 0.17 to 0.25. The estimates of genetic correlations among the traits ranged between -0.28 (Ka-Kb) and 0.99 (ADGb-Kb). The moderate estimates of heritability, high and positive genetic correlations among the traits in the study were suggestive of moderate genetic progress in the Nellore breed of sheep through selection.

Normal growth and development up to one year of age of Sudanese cattle with special reference to the influence of Sex and sire

1968 ◽  
Vol 70 (2) ◽  
pp. 117-121 ◽  
Author(s):  
A. H. Osman ◽  
Y. Rizgalla
Keyword(s):  
Growth And Development ◽  
Average Daily Gain ◽  
Normal Growth ◽  
Body Measurements ◽  
Weaning Weight ◽  
Body Weights ◽  
Weaning Age ◽  
Heritability Estimates ◽  
One Year ◽  
Daily Gain

SUMMARYThree years' data on a herd of Sudanese cattle were used to study the influence of sex and sire on their growth from birth to 1 year of age. The traits studied included body weights at birth, weaning and yearling ages, and body measurements at birth and weaning age. Analysis of variance indicated no significant sex by sire interactions. Male calves had significantly (P < 0.01) heavier birth, weaning and yearling weights and faster pre-weaning average daily gain than female calves. There were no statistically significant differences between sexes in post-weaning gain or body measurements. The sire effects were highly significant (P < 0.01) for birth and yearling weights and postweaning average daily gain, but not for weaning weight and pre-weaning average daily gain. Sire effects were also significant (P < 0.05) for height at withers and heart girth at birth and weaning age and for body length at weaning age. The heritability estimates of birth and yearling weights and post-weaning gain were relatively high, whereas the heritability estimates of weaning weight and pre-weaning gain were low.

ESTIMATES OF GENETIC CORRELATIONS AMONG CERTAIN CARCASS AND PERFORMANCE TRAITS IN SWINE

1968 ◽  
Vol 48 (1) ◽  
pp. 1-6 ◽  
Author(s):  
G. L. Roy ◽  
W. J. Boylan ◽  
M. E. Seale
Keyword(s):  
Birth Weight ◽  
Genetic Correlation ◽  
Genetic Relationships ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Development Project ◽  
Carcass Trait ◽  
Selection For ◽  
And Performance ◽  
Daily Gain

Data from a swine breed development project provided estimates of the genetic correlation among six performance and carcass traits. The data from the new breed, called Managra, were obtained over a 7-year period. Most genetic relationships examined were such that selection for improvement of one trait would yield a favorable improvement in another. Both carcass backfat and live backfat probe were found to be negatively correlated with area of loin eye and length of carcass. A positive genetic correlation was found between post-weaning daily gain and loin eye area. A high positive genetic correlation was found between birth weight and loin eye area. An unfavorable association involved a positive genetic correlation between birth weight and backfat.Correction factors for effect of carcass weight on the magnitude of carcass trait measurements and differences in means between sexes were obtained.Heritability of the traits was estimated by paternal half-sib correlation. The estimates for carcass traits were moderately high and agree well with most other estimates reported in the literature.

The genetic foundation of fitness and reproduction traits in Australian pig populations. 2. Relationships between weaning to conception interval, farrowing interval, stayability, and other common reproduction and production traits.

1996 ◽  
Vol 47 (8) ◽  
pp. 1275 ◽  
Author(s):  
E Tholen ◽  
KL Bunter ◽  
S Hermesch ◽  
HU Graser
Keyword(s):  
Genetic Parameters ◽  
Performance Test ◽  
Genetic Relationships ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Data Sets ◽  
Production Traits ◽  
Breeding Programs ◽  
Reproduction Traits ◽  
Daily Gain

Data sets from 2 large Australian piggeries were used to estimate genetic parameters for the traits weaning to conception interval (WCIi-l,i) and farrowing interval (FIi-l,i), number born alive (NBAI), average piglet birthweight (BWi), 21-day litter weight (W21i), and sow stayability (STAYli) recorded for each ith parity, as well as sow average daily gain (ADG) and backfat (BF) recorded at the end of performance test. Over parities and herds, heritabilities for each trait were in the ranges: WCI/FI, 0.0-0.10; NBA, 0.09-0.16; BW, 0.11-0.35; W21, 0.12-0.23; STAYli, 0.02-0.09; ADG, 0.35-0.37; BF, 0.36-0.45. Genetic correlations between NBAl and NBA from later parities were significantly different from 1. In addition, in 1 herd negative genetic correlations (rg = -0.04 to -0.25) were found between sow stayability traits and NBA1, but not NBA recorded in later parities. Stayability was Unfavourably correlated with ADG and BF, and favourably correlated with WCI12. However, WCI12 was unfavourably correlated genetically with BF (rg = -0.24) but uncorrelated with ADG. Antagonistic relationships also existed between NBA and BW, NBA and W21, and BW and STAY. In addition to the traditional traits currently included in pig-breeding programs (e.g. ADG, BF, and NBA), traits such as WCI, BW, and STAY should also be considered as selection criteria to minimise the detrimental effects of antagonistic genetic relationships between traits.

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