Genetic parameters among lactational performance traits in Murrah buffaloes

2015 ◽  
Author(s):  
A. Godara ◽  
D. Singh ◽  
S. S. Dhaka
Keyword(s):  
Genetic Correlation ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Research Centre ◽  
Murrah Buffaloes ◽  
Performance Traits ◽  
Lactational Performance ◽  
Almost All ◽  
Animal Sciences

The data pertinent to lactational performance traits on Murrah buffaloes calved during period 1987 to 2002, progeny of 52 sires maintained at Buffalo Research Centre, LLR University of Veterinary and Animal Sciences, Hisar were considered. The estimates of heritability were obtained low to moderate for almost all lactational performance traits. All the first lactation traits viz., AC1, SP, CI, MY, LL, PY, DAPY and MY/LL had moderate to high positive genetic correlations among themselves except PY with CI and DAPY with AC1, which is negative. Age at calving (AC2) had moderate positive genetic correlation with second lactational performance traits like SP, MY, LL, PY, MY/LL and MY/CI and had negative correlations with DAPY and DP. Moreover, third lactational traits like milk yield, LL, PY, DAPY, MY/LL and MY/CI had high positive genetic correlations among themselves. However, age at calving during fourth lactation had positive genetic correlations with all the traits except CI, DAPY and DP which had negative genetic correlations with it. It is inferred that information on sip performance and other relatives coupled with better husbandry practices would be required to bring desirable improvement in these lactational performance traits.

Genetic parameters for feed intake and efficiency in lactating beef cows

1996 ◽  
Vol 76 (1) ◽  
pp. 81-87 ◽  
Author(s):  
L. Q. Fan ◽  
J. W. Wilton ◽  
P. E. Colucci
Keyword(s):  
Milk Yield ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
National Research Council ◽  
Beef Cows ◽  
Feed Consumption ◽  
Research Centre ◽  
Total Data

Genetic parameters of feed intake and efficiency and production traits for lactating beef cows were estimated from data collected from 1980 to 1988 at the Elora Beef Research Centre, Guelph, Ontario. Estimates were obtained using restricted maximum likelihood (REML) with an individual animal model with year–season–treatment, sex of calf, parity, breeding system, covariate daily change of backfat depth and direct genetic and permanent environmental effects. The data included 1174 observations, 511 cows, 369 dam–maternal grand dam pairs and 245 sires of cows. Feed efficiency for milk was calculated as milk yield relative to energy consumed for milk and maintenance and residual feed consumption as estimated energy intake minus energy requirements as estimated by the National Research Council. Heritabilities for Herefords alone and total data, respectively, were estimated to be 0.02 and 0.11 for cow's daily ME intake (MEI), 0.26 and 0.26 for daily milk yield (DMY), 0.45 and 0.33 for milk fat percentage (MFP), 0.29 and 0.40 for metabolic body weight (MBW), 0.21 and 0.10 for calf weaning weight as a proportion of cow weight at weaning (PPW), 0.18 and 0.11 for feed efficiency for milk (FE), and 0.23 and 0.03 for residual feed consumption (RFC). Genetic correlations of output (DMY) and input (MEI) were 0.31 for Hereford and 0.75 for the total data. Genetic correlations of RFC with both output (DMY) and input (MEI) were low. Genetically, PPW was positively associated with FE and DMY and negatively associated with MBW. Key words: Genetic parameters, feed efficiency, lactation, beef cow

scholarly journals Schätzung genetischer Parameter für Testtagsergebnisse von Milchleistungsmerkmalen bei Bunten Deutschen Edelziegen

2004 ◽  
Vol 47 (2) ◽  
pp. 193-202
Author(s):  
D. Bömkes ◽  
H. Hamann ◽  
O. Distl
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Protein Yield ◽  
Lower Saxony ◽  
Genetic Progress ◽  
Performance Traits ◽  
Milk Performance

Abstract. Title of the paper: Estimation of genetic parameters for test day records of milk performance traits in German Improved Fawn The objectives of this study were to estimate genetic parameters for milk performance traits of German Improved Fawn by using univariate und multivariate animal models. The analysis was based on 27,778 test day records of 1,848 German Improved Fawn with 3,574 lactation records distributed over 229 flocks in Lower Saxony, Saxony and Baden-Wuerttemberg. Milk records were sampled between 1988 and 2002. The animals in our analysis were the progeny of 455 sires and 1.148 does. Heritabilities estimated with a multivariate test day model with fixed regression were h2 = 0.19, 0.16 and 0.15 for milk, fat and protein yield. For fat and protein content and Somatic Cell Score (SCS) heritabilities were h2 = 0.17, 0.14 and 0.16, respectively. The additive genetic correlations between milk yield and fat as well as protein yield of German Improved Fawn were very high and positive (rg = 0.84 and rg = 0.77). Milk yield and milk contents were genetically negative correlated with rg = −0.28 for fat and rg = −0.22 for protein content. A moderate additive genetic correlation (rg = 0.48) between fat and protein content was estimated. There were no considerable additive genetic correlations between fat yield and protein content as well as between fat content and protein yield (rg = 0.05 and rg = 0.09). Additive genetic correlations between milk, fat or protein yield and SCS were high and negative, whereas additive genetic correlations between fat or protein content and SCS were low and positive. The genetic parameters estimated from field test records allow to achieve genetic progress in milk performance traits of German Improved Fawn.

Prediction of phenotypic value of lifetime performance traits on the basis of early performance traits in Murrah buffaloes

2017 ◽  
Vol 36 (02) ◽  
Author(s):  
Kapil Dev ◽  
S. S. Dhaka ◽  
A. S. Yadav
Keyword(s):  
Milk Yield ◽  
Life Time ◽  
Research Centre ◽  
Direct Selection ◽  
Murrah Buffalo ◽  
Murrah Buffaloes ◽  
Lifetime Performance ◽  
Performance Traits ◽  
Early Performance ◽  
Calving Intervals

In order to achieve the objective, data pertaining to 171 Murrah buffaloes, progeny of 49 sires maintained at Buffalo Research Centre, Hisar were considered for the prediction of lifetime traits from early lactation traits over a period of 24 years from 1990 to 2013. The prediction of phenotypic values of lifetime performance traits viz. Life time milk yield (LTMY), Production life (PL), Milk yield per day of productive life (MY/PL), herd life (HL) and milk yield per day of herd life (MY/HL) were obtained. The equation having the combination of first five lactation traits is recommended for the prediction of phenotypic value of lifetime traits in Murrah buffalo. Accuracy of direct selection for LTMY, PL, MY/PL, HL and MY/HL was 0.42, 0.51, 0.33, 0.51 and 0.54, respectively. The index involving independent variables of first lactation early performance traits had an accuracy of 0.40, 0.39, 0.37, 0.19 and 0.37 for LTMY, PL, MY/PL, HL and MY/HL, respectively. Generally the first lactation milk yield, first peak milk yield and first calving intervals of all lactations contributed maximum to R2 value for all lifetime traits. Therefore, it may be concluded that selection on the basis of first lactation milk yield, first peak yield and first calving interval would also improve the lifetime performance.

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.

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 The use of dijkstra mechanistic model for genetic analysis of the lactation curve characteristics and their relationships with age at first calving and somatic cell score of Iranian dairy cows

2020 ◽  
Vol 42 ◽  
pp. e50181
Author(s):  
Mahdi Elahi Torshizi ◽  
Homayoun Farhangfar
Keyword(s):  
Somatic Cell ◽  
Genetic Correlation ◽  
Milk Yield ◽  
Mechanistic Model ◽  
Genetic Correlations ◽  
Somatic Cell Score ◽  
Specific Rate ◽  
Lactation Period ◽  
Age At First Calving ◽  
Lactation Curve

The objective of this study was to estimate lactation curve parameters with Dijkstra mechanistic model and to evaluate genetic and phenotypic relationships between the parameters and the average somatic cell count in primiparous cows. The finding indicated that heritability estimates for partial milk yield (PMY1, PMY2 and PMY3), total 305-day milk yield (TMY305), decay parameter (λ2), age at first calving (AFC) and peak yield (PY) were moderate while the heritability of persistency (PS%), average somatic cell score (AVGSCS), time to peak yield (TP), initial milk production (λ0), specific rate of cell proliferation at parturition (λ1), and specific rate of cell death (λ3) were quite low. Genetic correlations between both AFC and PS% traits with average somatic cell scores was negative (-0.047 and -0.060) but low positive genetic correlation were between partial milk yields (PMY1 and PMY3) while negative genetic correlation (-0.06) was obtained between TMY305 and AVGSCS. Differences between TMY305 of cows with less than 100000 cells mL-1 and cows with >1,500,000 cells mL-1 was approximately 708 Kg and is equivalent to 8% loss of milk yield/cow during lactation period and also loss of persistency (11.1 %( was shown for the extreme classes of SCC in this study.

scholarly journals Genetic parameters of production and reproduetive traits in on a farm tested Danish Large White and Landrace swine in Greece

2000 ◽  
Vol 43 (3) ◽  
pp. 287-298
Author(s):  
J. Bizelis ◽  
A. Kominakis ◽  
E. Rogdakis ◽  
F. Georgadopoulou
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Likelihood Methods ◽  
Large White ◽  
Reproduction Traits ◽  
Maximum Likelihood Methods ◽  
Genetic And Phenotypic Correlations

Abstract. Production and reproduetive traits in Danish Landrace (LD) and Large White (LW) swine were analysed by restricted maximum likelihood methods to obtain heritabilities as well as genetic and phenotypic correlations. Production traits were: age, backfat thickness (BT), muscle depth (MD) and the ratio BT/MD, adjusted to Standard bodyweight of 85 kg. Reproduction traits were: number of pigs born (NB) and number of pigs weaned (NW) per sow and parity. Heritabilities for age, BT, MD and BT/MD were 0.60, 0.44, 0.51 and 0.42 for LD and 0.36, 0.44, 0.37 and 0.45 for LW, respectively. Genetic correlations between age and BT were −0.22 in LD and – 0.44 in LW. The genetic correlation between age and MD was close to zero in both breeds. Genetic correlation between BT and MD were −0.36 and −0.25 in LD and LW, respectively. Heritabilities for NB were 0.25 in LD and 0.13 in LW while heritabilities for NW were close to zero in both breeds. Genetic correlation between NB and NW was 0.46 and 0.70 in LD and LW, respectively.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

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 > 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P < 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.

Genetic parameter estimations and genomic insights for teat and udder structure in young and mature Canadian Angus cows

2021 ◽  
Author(s):  
K Devani ◽  
J J Crowley ◽  
G Plastow ◽  
K Orsel ◽  
T S Valente
Keyword(s):  
Animal Model ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Age Groups ◽  
Morbidity And Mortality ◽  
Parameter Estimations ◽  
Angus Cattle ◽  
Genetic Evaluations

Abstract Poor teat and udder structure, frequently associated with older cows, impact cow production and health, as well as calf morbidity and mortality. However, producer culling, for reasons including age, production, feed availability, and beef markets, creates a bias in teat and udder scores assessed and submitted to the Canadian Angus Association for genetic evaluations towards improved mammary structure. In addition, due to the infancy of the reporting program, repeated scores are rare. Prior to adoption of genetic evaluations for teat and udder scores in Canadian Angus cattle, it is imperative to verify that teat and udder scores from young cows are the same trait as teat and udder scores estimated on mature cows. Genetic parameters for teat and udder scores from all cows (n=4,192), and then from young cows (parity 1 and 2) and from mature cows (parity ≥ 4) were estimated using a single trait animal model. Genetic correlations for the traits between the two cow age groups were estimated using a two-trait animal model. Estimates of heritability (PSD) were 0.32 (0.07) and 0.45 (0.07) for young teat and udder score, and 0.27 (0.07) and 0.31 (0.07) for mature teat and udder score, respectively. Genetic correlation (PSD) between the young and mature traits was 0.87 (0.13) for teat score and 0.40 (0.17) for udder score. GWAS were used to further explore the genetic and biological commonalities and differences between the two groups. Although there were no genes in common for the two udder scores, 12 genes overlapped for teat score in the two cow age groups. Interestingly, there were also 23 genes in common between teat and udder scores in mature cows. Based on these findings, it is recommended that producers collect teat and udder score on their cow herd annually.

Genetic parameters for egg weight v. age curve, and other egg production and egg weight traits, in synthetic lines of chickens

1983 ◽  
Vol 34 (1) ◽  
pp. 85 ◽  
Author(s):  
BH Yoo ◽  
BL Sheldon ◽  
RN Podger
Keyword(s):  
Standard Deviation ◽  
Genetic Correlation ◽  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Egg Mass ◽  
Control Line ◽  
Egg Weight ◽  
Egg Number ◽  
Selection For

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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