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

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.

1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.


1999 ◽  
Vol 79 (1) ◽  
pp. 17-25 ◽  
Author(s):  
D. H. Crews Jr. ◽  
R. A. Kemp

Preweaning and carcass trait records from crossbred steers (n = 1015) and heifers (n = 957) were used to estimate genetic parameters and to investigate the efficacy of maternal effects and preweaning growth information for improving estimation of EBV for carcass traits for crossbred beef cattle. Dams (n = 775) representing three F1 and twelve back-cross combinations involving the Charolais, Hereford, Angus, Simmental and Shorthorn breeds were mated over six years to Limousin bulls (n = 36) at two locations in western Canada. Four animal models, involving from zero to three maternal (co)variances were used to analyze four carcass traits. Rank and simple correlations indicated that maternal effects were relatively unimportant for estimation of direct carcass trait breeding values. Direct heritabilities were 0.28, 0.12 and 0.16 for birth weight, preweaning daily gain and weaning weight, and were 0.20, 0.35, 0.50 and 0.38 for hot carcass weight, fat thickness, ribeye area and percent lean yield, respectively. Maternal heritabilities were 0.21, 0.22 and 0.40 for birth weight, preweaning daily gain and weaning weight, respectively. Estimated genetic correlations between percent lean yield and hot carcass weight, fat thickness and ribeye area were –0.05, –0.85 and 0.39, respectively, and 0.30 between hot carcass weight and ribeye area. Direct genetic effects for birth weight had moderate (0.51 to 0.54) correlations with direct effects for carcass weight, ribeye area and percent lean yield. Direct genetic effects for fat thickness were negatively correlated with direct effects for birth weight (−0.44), preweaning daily gain (−0.15) and weaning weight (−0.25). Maternal genetic effects for preweaning traits had near-zero correlations with direct genetic effects for fat thickness and percent lean yield. Adding preweaning growth information to genetic evaluations for carcass traits slightly decreased prediction error variances for breeding values and would be recommended when information on carcass traits is limited. Key words: Genetic evaluation, carcass traits, beef cattle


1975 ◽  
Vol 26 (6) ◽  
pp. 1093 ◽  
Author(s):  
GW Seifert

The response to one generation of selection for weight per day of age at 18 months (W/Af), in Africander cross (AX) and Brahman cross (BX) cattle, was evaluated in the female offspring of the up and down selected parents. The high W/A< line gained significantly more than the low line over a year from weaning. The advantage of the high W/A line occurred during flush nutritional periods. The realized heritability (h2) of W/Af at 18 months was 0.52, while the estimates of h2 from mid-parental means computed within sires was higher. Heritability estimates for birth weight (Wb), weaning weight per day of age (W/Aw), pre-weaning average daily gain (Gbw) and total average daily gain from birth to final weight (Gt) were all high, while the estimate for post-weaning average daily gain from weaning to final weight (Gpw) was low. The correlated responses of all the traits were high. The genetic correlations estimated from the response and the parent-offspring regressions were all positive and high. Birth weight was the most highly correlated with Gt. All phenotypic correlations were positive but lower than the genetic correlations, the correlation between Gbw and Gpw being the lowest. Environmental correlations between birth weight and pre-weaning traits were essentially zero, and between birth weight and post-weaning traits and Gt, negative. Weight per day of age at 18 months appeared to be the most efficient and practical single trait to select beef cattle for increased growth rate.


2012 ◽  
Vol 40 (1-2) ◽  
pp. 1-7
Author(s):  
S Aktar ◽  
AKFH Bhuiyan ◽  
NG Saha ◽  
MA Hoque

Records on four bulls and 96 of their progeny born from 2005 to 2011 with pedigree information were used to estimate the impact of bull performance on progeny early growth and the genetic relationships between traits of bull and their progeny. Traits included in this study were metabolic body weight, feed intake and residual feed intake (RFI) for bull performance and birth weight and average daily gain for progeny performance. The variance and covariance components were estimated by the REML method with the VCE computer program. The metabolic body weight of breeding bulls ranged from 92.88±1.22 to 106.05±2.28 kg. The average daily feed intake of breeding bulls differed significantly (p<0.05). The RFI of breeding bulls were ranged from -0.57±0.07 to 0.54±0.06 kg/day. It has been found that the RFI values of two bulls were negative and the other two bulls were positive. The mean values for birth weight of calves produced from different breeding bulls ranged from 16.15±2.01 to 17.71±1.89 kg. Effects of breeding bulls on birth weight and average daily gain of male calves were highly significant (p<0.01). Mean values for birth weight and average daily gain of female calves were affected also significantly (p<0.05) among breeding bulls. Estimated heritability for birth weight was moderate (0.30) and for average daily gain was low (0.26). The genetic correlation between metabolic body weight of bulls and birth weight of their progeny was strong (rg=0.52), whereas feed intake of bulls with birth weight and average daily gain of their progeny were moderate (0.43±0.21 and 0.40±0.23, respectively). Low but favorable negative genetic correlation (rg=-0.10) was observed between RFI of bulls with average daily gain of their progeny. Estimated moderate heritability indicated that variation exist on average daily gain of calves. The negative genetic correlation between RFI of bulls and average daily gain of their progeny indicated that it was possible to improve simultaneously RFI of breeding bulls and daily gain of their progeny. DOI: http://dx.doi.org/10.3329/bjas.v40i1-2.10620 Bang. J. Anim. Sci. 2011. 40 (1-2): 1-7


2004 ◽  
Vol 78 (2) ◽  
pp. 195-201 ◽  
Author(s):  
K. Oyama ◽  
T. Katsuta ◽  
K. Anada ◽  
F. Mukai

AbstractReproductive performance is receiving increased attention from beef cattle producers. There are concerns that intensive selection for carcass traits might reduce the reproductive performance of females. Genetic parameters among six carcass traits and, age at first calving (AFC), gestation length (GL), days open (DO) and calving interval (CI) under year-round artificial insemination were estimated. Reproductive traits were extracted from 174005 calving records of Japanese Black cows and were analysed with 31364 carcass records. The restricted maximum likelihood procedure under animal models was used to estimate the parameters. Heritabilities of AFC, GL, DO and CI were estimated to be 0.20, 0.40, 0.05 and 0.05, respectively, and those of carcass traits were higher, ranging from 0.38 to 0.56. Genetic correlations of CI with AFC and GL were 0.25 and 0.16, respectively, while no relationship was observed between AFC and GL. Correlations among carcass traits were generally favourable and a slightly negative estimate was obtained between subcutaneous fat thickness and marbling score. Genetic correlations for AFC were -0.27 with carcass weight and -0.24 with marbling score. In contrast, GL, DO and CI were genetically independent of carcass traits. Genetic relationships between reproductive and carcass traits were generally low, and therefore serious antagonism was not observed. The results suggested that selection for carcass traits would not compromise genetic progress in reproductive traits.


1982 ◽  
Vol 34 (3) ◽  
pp. 257-264 ◽  
Author(s):  
B. T. Wolf

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.


1982 ◽  
Vol 62 (3) ◽  
pp. 665-670 ◽  
Author(s):  
D. C. JEFFRIES ◽  
R. G. PETERSON

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


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P &gt; 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P &lt; 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.


2009 ◽  
Vol 49 (6) ◽  
pp. 413 ◽  
Author(s):  
K. C. Prayaga ◽  
N. J. Corbet ◽  
D. J. Johnston ◽  
M. L. Wolcott ◽  
G. Fordyce ◽  
...  

Genetic analyses of tropical adaptive traits were conducted for two tropically adapted genotypes, Brahman (BRAH) and Tropical Composite (TCOMP). Traits included tick scores (TICK), faecal egg counts (EPG), buffalo fly-lesion scores (FLY), rectal temperatures under hot conditions (TEMP), coat scores (COAT), coat colour on a light to dark scale (COLOUR), navel scores (NAVEL) and temperament measured as flight time (FT). The data comprised adaptive measures recorded at specific times on 2071 heifers comprising 966 BRAH and 1105 TCOMP. The genetic correlations of these adaptive traits with heifer growth, scanned carcass, pubertal measures and steer growth and carcass traits were estimated. BRAH recorded significantly (P < 0.05) lower TICK, EPG, FLY and TEMP than did TCOMP. BRAH also had significantly sleeker coats, lighter coat colour, more pendulous navels and more docile temperament than did TCOMP. The heritability of TICK and FLY was low (<20%), that of EPG, TEMP, NAVEL and FT was moderate (20–50%) and that of COAT and COLOUR high (>50%). In general, phenotypic correlations between these adaptive traits were low and genetic correlations were non-significant, implying trait independence. Genetic correlations between EPG and weight traits (0.29 to 0.44) indicated a positive relationship, implying no deleterious effect of worms on the growth at a genetic level, especially in TCOMP. The negative genetic correlations between COAT and body-condition score across genotypes (–0.33 to –0.48) indicated genetic advantage of sleek coats in tropics. A positive genetic correlation between COAT and the age at the first-observed corpus luteum (0.73) in BRAH indicated that BRAH with sleeker coats were genetically early maturing. Further, sleeker coats were genetically indicative of lower weights and lower fat cover at puberty in BRAH. The scanned fat measures at rump and rib sites for feedlot steers showed strong genetic correlation (0.50–0.58) with heifer TEMP, indicating genetically fatter animals had genetically lower heat tolerance. In BRAH, a positive genetic association between heifer COLOUR and scanned fat measures in steers (0.50–0.54) implied increased fatness in genetically darker animals. Further, in BRAH, a strong negative genetic correlation (–0.97) was observed between steer retail beef yield and heifer TEMP, indicating a favourable genetic association. In general, genetic correlations between adaptive traits and other economic traits were genotype specific. Further, it can be concluded that selection for productive and pubertal traits in tropical beef cattle genotypes would not adversely affect their tropical adaptability.


1983 ◽  
Vol 34 (1) ◽  
pp. 85 ◽  
Author(s):  
BH Yoo ◽  
BL Sheldon ◽  
RN Podger

An exponential curve, W = P-Qexp(- Rt), where W is egg weight at age t, was fitted to egg weights of individual pullets, and genetic parameters were estimated for P, Q and R, the residual standard deviation and other egg weight and egg production characters. The data consisted of records collected over six generations on more than 4000 pullets in two selection lines and a control line which originated from a synthetic gene pool of White Leghorn x Australorp crosses. The half-sib and offspring-on-parent regression estimates of heritability pooled over the lines were 0.23 and 0.33 for P, 0.14 and 0.20 for Q, and 0.14 and 0.25 for R. Genetic correlations were estimated to be -0.10 between P and Q, -0.46 between P and R, and 0.90 between Q and R. These estimates suggest that the egg weight v. age curve may be modified to increase the proportion of eggs in desirable weight grades and reduce the incidence of oversized eggs later in the production year. The genetic correlation between mean weight of first 10 eggs and egg weight at 62 weeks of age was estimated to be 0.68, further suggesting that early egg weight may be improved partly independently of late egg weight. The heritability estimates of egg mass output were not higher than those of egg number in spite of the highly heritable average egg weight being an important component of egg mass, probably because of the negative genetic correlation (r = -0.49) between egg number and average egg weight. The standard deviation of individual pullet's egg weights was moderately heritable and genetically correlated positively with egg weight characters and negatively with egg production; these estimates were consistent with the responses to selection for reduced egg weight variability observed elsewhere


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