• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1387-1393
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• 2014

This study aimed to estimate genetic correlation between carcass grading and retail productivity traits and to estimate the correlated response on retail productivity traits through selection for carcass grading traits in order to assess the efficacy of indirect selection. Genetic parameters were estimated with the data from 4240 Hanwoo steers using mixed models, and phenotypes included carcass weight (CWT), back fat thickness (BFT), eye muscle area (EMA), marbling (MAR), and estimated lean yield percentage (ELP) as the carcass grading traits, and weight and portion of retail cuts (RCW and RCP), trimmed fats (TFW and TFP) and trimmed bones (TBW and TBP) as the lean productivity traits. The CWT had positive genetic correlations with RCW (0.95) and TFW (0.73), but its genetic correlation with RCP was negligible (0.02). The BFT was negatively correlated with RCP (-0.63), but positively correlated with TFW and TFP (0.77 and 0.70). Genetic correlations of MAR with TFW and TFP were low. Among the carcass grading traits, only EMA was positively correlated with both RCW (0.60) and RCP (0.72). The EMA had a relatively strong negative genetic correlation with TFW (-0.64). The genetic correlation coefficients of ELP with RCP, TFW, and TFP were 0.76, -0.90, and -0.82, respectively. These correlation coefficients suggested that the ELP and EMA might be favorable traits in regulating lean productivity of carcass.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.883-887
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• 2000

One way of evaluating the effectiveness of a dairy breeding program is to measure response to selection. This may be direct or indirect. The objectives of this study were to estimate expected progress for direct selection on milk, fat and protein yields; to estimate the expected correlated responses on indirect selection for milk, fat and protein yields in Zimbabwean Holstein cattle and to establish the effect of selection intensity on responses. The Animal Model contained fixed effects of herd, year of calving, calving month, dry period, milking frequency and additive effects pertaining to cows, sires and dams. AIREML software package was used to analyse the data. The genetic and phenotypic parameters obtained in this study were used to compute direct and correlated responses to selection. Because of the higher heritabilities in first parity, genetic progress was found to be greater when selection was practised on first parity cows as compared to later lactations. It is therefore recommended that older cows in the herd be replaced with improved heifers so as to enhance genetic progress.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1690-1694
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• 2002

Genetic parameters were estimated for birth weight and weaning weight from three year (1991-1993) data totalling 1100 records of 25 rams to 205 ewes of Indigenous Sabi flock maintained at Grasslands Research Station in Zimbabwe. AIREML procedures were used fitting an Animal Model. The statistical model included the fixed effects of year of lambing, sex of lamb, birth type and the random effect of ewe. Weight of ewe when first joined with ram was included as a covariate. Direct heritability estimates of 0.27 and 0.38, and maternal heritability estimates of 0.24 and 0.09, were obtained for birth weight and weaning weight, respectively. The total heritability estimates were 0.69 and 0.77 for birth weight and weaning weight, respectively. Direct-aternal genetic correlations were high and positive. The corresponding genetic covariance estimates between direct and maternal effects were positive and low, 0.25 and 0.18 for birth weight and weaning weight, respectively. Responses to selection were 0.8 kg and 0.14 kg for birth weight and weaning weight, respectively. The estimated expected correlated response to selection for birth weight by directly selecting for weaning weight was 0.26. Direct heritabilities were moderate; as a result selection for any of these traits should be successful. Maternal heritabilities were low for weaning weight and should have less effect on selection response. Indirect selection can give lower response than direct selection.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.8-12
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• 2005

Response in a modified reciprocal recurrent selection scheme for egg production was evaluated considering variable family sizes and genetic correlation between purebred and crossbred half sisters. The criteria of selection of purebred breeders included pullet's own performance, purebred full and half sisters and crossbred half sister's performance. Heritability of egg production of crossbreds (aggregate genotype) and purebred's was assumed to be 0.2 and genetic correlation between purebred and crossbred half sisters ($r_{pc}$) as 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, -0.1, -0.2, -0.3, -0.4, -0.5 and -1.0. Number of dams per sire to produce purebred and crossbred progenies assumed to be 5, 6, 7, 8, while number of purebred female progeny ($N_p$) and crossbred progeny ($N_c$) per dam were considered to be 3, 4, 5 and 6 in each case. Considering phenotypic variance as unity, selection indices were constructed for different combinations of dams and progeny for each value of $r_{pc}$. Following selection index theory, response in crossbred and purebred for egg production was computed. Results indicated that response in crossbreds depended mainly on crossbred family size and also on magnitude of$r_{pc}$ irrespective of its direction, and response was greater with large crossbred family size than the purebred families. Correlated response in purebreds depends both on magnitude and direction of $r_{pc}$ and was expected to be greater with large purebred family size only. Inclusion of purebred information increased the accuracy of selection for crossbred response for higher magnitude of$r_{pc}$ irrespective of its direction. Present results indicate that desirable response in both crossbred and purebred performance is a function of $r_{pc}$ and family sizes. The ratio of crossbred and purebred family sizes can be optimized depending on the objective of improving the performance of crossbreds and/or of purebreds.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.789-793
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• 2003

An investigation was conducted on 729 Hariana cows maintained at Government Livestock Farm, Hisar, from 1973 to 1999, with an objective to compare the efficiency of various selection indices for attaining desired genetic gains in the index traits. The various traits included were age at first calving (AFC), service period (SP), calving interval (CI), days to first service (DFS), number of services per conception (NSPC), lactation milk yield (LY), peak yield (PY), dry period (DP). Except for LY, PY and AFC the heritabilities of all other traits were low. Desirable associations among reproductive traits are supportive of the fact that any one of these traits incorporated in simultaneous selection is expected to cause correlated response in other traits. Production traits (LY and PY) were positively correlated, while DP had low negative genetic correlation with LY, and high genetic correlation with PY. Thus, DP can be taken as additional criteria in selection index for better over all improvement. Almost all production traits except DP had low negative correlation with AFC, SP, DFS and CI meaning that reduction in reproduction traits up to certain level may increase production performance. While, the correlation of NSPC with LY and PY was moderate positive. Among four trait indices I23: incorporating PY, AFC, SP and NSPC and among three trait indices I1: incorporating LY, AFC and SP were the best as these required least number of generations (4.87 and 1.35, respectively) to attain desired goals. Next in order of preference were PY or LY along with DP and SP as the best indices (I20 and I16) of which, index with PY may be preferred instead of LY as it produced considerably high correlated response in LY and reduction in NSPC as well.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.713-718
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• 2015

Background: A number of association studies have been carried out to investigate the relationship between genetic polymorphisms in DNA repair genes and response to radiotherapy-based multimodality treatment of patients with rectal cancer. However, their conclusions were inconsistent. The objective of the present study was to assess the role of DNA repair gene genetic polymorphisms in predicting genetic biomarkers of the response in rectal cancer patients treated with neoadjuvant chemoradiation. Materials and Methods: Studies were retrieved by searching the PubMed database, Cochrane Library, Embase, and ISI Web of Knowledge. We conducted a meta-analysis to evaluate the association between genetic polymorphisms and the response in rectal cancer treated with neoadjuvant chemoradiation by checking odds ratios (ORs) and 95% confidence intervals (CIs). Results: Data were extracted from 5 clinical studies for this meta-analysis. The results showed that XRCC1 RS25487, XRCC1 RS179978, XRCC3 RS861539, ERCC1 RS11615 and ERCC2 RS13181 were not associated with the response in the radiotherapy-based multimodality treatment of patients with rectal cancer (p>0.05). Conclusions: This study shows that DNA repair gene common genetic polymorphisms are not significantly correlated with the radiotherapy-based multimodality treatment in rectal cancer patients.

• Korean Journal of Poultry Science
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• v.9 no.1
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• pp.35-42
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• 1982

Data pertaining to the first generation of a Synthetic White Leghorn flock were used to estimate the heritabilities of and genetic correlation between partial egg production(egg number or percentage) or diversely segmented part records and other traits such as age at sexual maturity, residual and annual egg production, and to compare the expected genetic gain from selection on partial egg number or partial percent production with correlated response in other traits. The estimated heritabilites for six measures of egg Production were ranged from 29 to 35, while heritability for age at sexual maturity (SM) was intermediate (48). Genetic correlations between partial egg number (P) and annual egg number. (A), and partial percent production (P') and annual percent production (A') were 51 and 72, respectively. Genetic correlation between P and SM was estimated largely negative (-.64), while correlation bettween P' and SM was positively intermediate(34). In comparing direct response from selection on partial production (P or P') with another response in correlated trait, selection on P would be 25% more efficient than selection of P' for improving A, while selection of P' would be 94% more efficient than selection P for improving A' For shortening SM selection of P would be 98% more efficient than selection on P'.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.899-904
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• 2001

A field trial on selection for increased live weight in Black Bengal (BB) goat was conducted over two generations. Parents of both sexes were selected (mass selection) based on mature body weight criteria set against age. A parallel randomly mated line was maintained to compare the response (R) of selection at birth. 3, 6, 9 and 12 months of age in both generations. Lactation yield (LY), average per day yield (APDY) and lactation length (LL) were evaluated in the selected line in comparison to randombreds as a result of correlated response. Live weights were significantly improved at onward bir:th in first generation and only at birth in second generation. Improvements (%) in live weight at 3, 6. 9 and 12 months in first generation were 17.6, 18.4, 16.6, and 12.0 at birth in second generation. Significant correlated R were found in LY and APDY. Results suggest that there may be a positive relationship between live weight and lactational traits in BB goats of Bangladesh. It was also concluded that such a field scheme can be effectively used for genetic improvement of goats in subsistence farming, at least for short term gain.

• Animal Bioscience
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• v.34 no.8
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• pp.1303-1308
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• 2021

Objective: The objective of this study was to define a new composite trait for Holstein dairy cows and evaluate the possibility of joint improvement in milk and fertility traits. Methods: A data set consisting 35,882 fertility related records (days open [DO], calving interval [CI], and number of services per conception [NSC], and total milk yield in each lactation [TMY]) was collected from 1998 to 2016 in Polish Holstein-Friesian breed herds. In this study TMY, DO, CI, and lactation length of each cow was used to obtain composite milk and fertility traits (CMF). Results: Moderate heritability (0.15) was estimated for composite trait that was higher than heritability of female fertility related traits: DO 0.047, CI 0.042, and NSC 0.014, and slightly lower than heritability of TMY 0.19. Favourable genetic correlations (-0.87) were estimated between CMF with TMY. Spearman rank correlation coefficients between breeding value of CMF with DO, CI, and TMY were high (>0.94) but with NSC were moderate (0.64). Selection on CMF caused favourable correlated genetic gains for DO, CI, and TMY. Different selection indices with different emphasis on fertility and milk production were constructed. The amount of correlated genetic gains obtained for DO and total milk production according to selection in CMF were higher than of genetic gains obtained for DO and TMY in selection indices with different emphasis on milk and fertility. Conclusion: The animal selection only based on a composite trait - CMF proposed in current study would simultaneously lead to favourable genetic gains for both milk and fertility related traits. In this situation CMF introduced in current study can be used to overcome to limitations of selection index and CMF could be useful for countries that have problems in recording traits, especially functional traits.

• Journal of Korean Society of Forest Science
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• v.94 no.2 s.159
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• pp.73-81
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• 2005

This study was conducted to examine the geographic variation among provenances of Pinus densiflora in survival rate and height growth at four test plantations (Jungsun, Chungju, Naju, and Jeju). The plantations were parts of the eleven provenance trials of Pinus densiflora established by Korea Forest Research Institute in 1996. The survival rate and height growth were significantly different among test plantations at $p{\leq}0.01$. Latitude and longitude of test plantation were negatively correlated with survival rate and height growth. On the other hand, annual mean temperature, mean temperature (Nov.~Feb.), extremely low temperature (Dec.~Feb.), and annual mean growing days of test plantation were positively correlated with these two. The relationships between growth variables and geographic variables were analysed with canonical correlation analysis. A considerable amount of variation in survival rate and height growth was explained by latitude, annual mean growing days, extremely low temperature (Dec.~Feb.) and extremely high temperature (Nov.~Feb.) of provenances. It is estimated that up to 47.1% and 67.4% of the genetic variability in survival rate and height growth was attributable to the environmental variability of the provenances, respectively. The response surface curve of survival rate and height growth was plotted against latitude and longitude to examine growth performance of provenances for each test site. Generally, the local provenances showed better survival rate and height growth.