scholarly journals Comparison between Factor Analysis from a Phenotypic and Genetic Correlation Matrix Using Linear Type Traits of Holstein Dairy Cows

1988 ◽  
Vol 71 (2) ◽  
pp. 477-484 ◽  
Author(s):  
M. Sieber ◽  
A.E. Freeman ◽  
P.N. Hinz
Keyword(s):  
Factor Analysis ◽  
Dairy Cows ◽  
Genetic Correlation ◽  
Correlation Matrix ◽  
Linear Type ◽  
Type Traits ◽  
Holstein Dairy Cows

scholarly journals Selection Response Due to Different Combination of Antagonistic Milk, Beef, and Morphological Traits in the Alpine Grey Cattle Breed

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1340
Author(s):  
Enrico Mancin ◽  
Cristina Sartori ◽  
Nadia Guzzo ◽  
Beniamino Tuliozi ◽  
Roberto Mantovani
Keyword(s):  
Genetic Correlation ◽  
Functional Traits ◽  
Performance Test ◽  
Genetic Relationships ◽  
Selection Index ◽  
Milk Traits ◽  
Linear Type ◽  
Dual Purpose ◽  
Type Traits ◽  
Selection Indexes

Selection in local dual-purpose breeds requires great carefulness because of the need to preserve peculiar traits and also guarantee the positive genetic progress for milk and beef production to maintain economic competitiveness. A specific breeding plan accounting for milk, beef, and functional traits is required by breeders of the Alpine Grey cattle (AG), a local dual-purpose breed of the Italian Alps. Hereditability and genetic correlations among all traits have been analyzed for this purpose. After that, different selection indexes were proposed to identify the most suitable for this breed. Firstly, a genetic parameters analysis was carried out with different datasets. The milk dataset contained 406,918 test day records of milk, protein, and fat yields and somatic cells (expressed as SCS). The beef dataset included performance test data conducted on 749 young bulls. Average daily gain, in vivo estimated carcass yields, and carcass conformation (SEUROP) were the phenotypes obtained from the performance tests. The morphological dataset included 21 linear type evaluations of 11,320 first party cows. Linear type traits were aggregated through factor analysis and three factors were retained, while head typicality (HT) and rear muscularity (RM) were analyzed as single traits. Heritability estimates (h2) for milk traits ranged from 0.125 to 0.219. Analysis of beef traits showed h2 greater than milk traits, ranging from 0.282 to 0.501. Type traits showed a medium value of h2 ranging from 0.238 to 0.374. Regarding genetic correlation, SCS and milk traits were strongly positively correlated. Milk traits had a negative genetic correlation with the factor accounting for udder conformations (−0.40) and with all performance test traits and RM. These latter traits showed also a negative genetic correlation with udder volume (−0.28). The HT and the factor accounting for rear legs traits were not correlated with milk traits, but negatively correlated with beef traits (−0.32 with RM). We argue that the consequence of these results is that the use of the current selection index, which is mainly focused on milk attitude, will lead to a deterioration of all other traits. In this study, we propose more appropriate selection indexes that account for genetic relationships among traits, including functional traits.

Genetic correlations between linear type traits, food intake, live weight and condition score in Holstein Friesian dairy cattle

1997 ◽  
Vol 64 (3) ◽  
pp. 385-392 ◽  
Author(s):  
R. F. Veerkamp ◽  
S. Brotherstone
Keyword(s):  
Food Intake ◽  
Genetic Correlation ◽  
Dry Matter ◽  
Genetic Correlations ◽  
Live Weight ◽  
Dry Matter Intake ◽  
Body Depth ◽  
Linear Type ◽  
Condition Score ◽  
Type Traits

AbstractVariance components were estimated from an animal model using a restricted maximum likelihood procedure which allowed for unequal design matrices and missing observations (VCE). Data sets containing: (i) 15 275 records of linear type classifications on heifers, (ii) 3399 live weight and condition scores measured at calving and (iii) 1157 records of yield, dry-matter intake, average live weight and condition score during the first 26 weeks of lactation; were analysed jointly.Heritability estimates for dry-matter intake, live weight and condition score in the largest data set were 0·44, 0·44 and 0·35 respectively and the genetic correlation between condition score and the yield traits ranged from −0·29 to −0·46. The genetic correlation between milk yield and average live weight was negative (−0·09) but after adjusting for the genetic variation in condition score this correlation was positive (0·29). Genetic correlations between live weight and stature, chest width, body depth and rump width were consistently high (0·52 to 0·64; 0·75 to 0·86; 0·59 to 0·81; 0·56 to 0·74, respectively). Chest width and body depth were little to moderately correlated with dry-matter intake (0·25 to 0·28 and 0·20 to 0·34 respectively), and angularity (−0·47 to −0·77) and chest width (0·32 to 0·73) appeared to be good predictors of condition score. These correlations showed that (i) the relative value of live weight compared with food intake capacity determines the optimum direction of selection for stature, chest width, body depth and angularity, and consequently the optimum size of the dairy cow, and that (ii) live weight, condition score and food intake can be predicted from the type traits with little loss in accuracy. A restricted index which maintains condition score at its current level was predicted to reduce overall (economic) genetic gain by 5%.

scholarly journals Genetic Aspects of Somatic Cell Count in Holstein Dairy Cows in Iran

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1637
Author(s):  
Hadi Atashi ◽  
Miel Hostens
Keyword(s):  
Dairy Cows ◽  
Somatic Cell ◽  
Cell Count ◽  
Genetic Correlation ◽  
Milk Yield ◽  
Somatic Cell Count ◽  
Random Regression ◽  
Fat Percentage ◽  
Protein Percentage ◽  
Holstein Dairy Cows

The aim of this study was to estimate the genetic parameters of somatic cell count (SCC) and its relationship with production traits in the first three parities in Iranian Holstein dairy cows. Data were 1,891,559 test-day records of SCC, milk yield, and milk compositions on 276,217 lactations on 147,278 cows distributed in 134 herds. The number of test-day records in the first, second and third parities were 995,788 (on 147,278 cows), 593,848 (on 85,153 cows), and 301,923 (on 43,786 cows), respectively. Test-day SCCs were transformed to somatic cell scores (SCS). A random regression test-day animal model through four-trait three-lactation was used to estimate variance components for test-day records of SCS and lactation traits were included. Gibbs sampling was used to obtain marginal posterior distributions for the various parameters using a single chain of 200,000 iterates in which the first 50,000 iterates of each chain were regarded as a burn-in period. The mean heritability estimates for SCS (0.15 to 0.18) were lower than those for milk yield (0.36 to 0.38), fat yield (0.30 to 0.31), protein yield (0.31 to 0.32), fat percentage (0.21 to 0.25), and protein percentage (0.21 to 0.22). Low negative genetic correlations ranging from −0.05 to −0.30 were found between SCS and yield traits (milk, fat, and protein yields). The genetic correlation found between SCS and fat percentage was close to zero, however, a low positive genetic correlation ranging from 0.12 to 0.17 was found between SCS and protein percentage. Based on the results, it can be concluded that genetic selection for decreasing SCS would also increase lactation yield. The estimates found in this study can be used to perform breeding value estimations for national genetic evaluations in Iranian Holsteins using a multiple-trait, multiple-lactation random regression model.

scholarly journals Factor Analysis of Linear Type Traits and Their Relation with Longevity in Brazilian Holstein Cattle

2014 ◽  
Vol 27 (6) ◽  
pp. 784-790 ◽  
Author(s):  
Elisandra Lurdes Kern ◽  
Jaime Araújo Cobuci ◽  
Cláudio Napolis Costa ◽  
Concepta Margaret McManus Pimentel
Keyword(s):  
Factor Analysis ◽  
Holstein Cattle ◽  
Linear Type ◽  
Type Traits

Genetic and phenotypic relationships between conformation and production traits in Ayrshire heifers

1994 ◽  
Vol 58 (3) ◽  
pp. 335-338 ◽  
Author(s):  
R. A. Mrode ◽  
G. J. T. Swanson
Keyword(s):  
Maximum Likelihood ◽  
Genetic Correlation ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Traits ◽  
Linear Type ◽  
Maximum Likelihood Procedure ◽  
Type Traits ◽  
The Relationship

AbstractFirst lactation records for production traits (milk, fat and protein yields) and 17 linear type traits for 7169 Ayrshire heifers were analysed to estimate genetic parameters for type traits and to examine the relationship between type and production traits. A multivariate restricted maximum likelihood procedure fitting a sire model with sire relationships included was used for all analyses.Heritabilities for production traits were approximately 0·3 and genetic correlations among them were high (>0·84). The estimates of heritabilities for type traits were mainly low to moderate ranging from 0·04 to 0·42. Angularity (0·80), beef shape (0·49), foot angle (0·53) and stature (0·46) had higher heritabilities. Generally phenotypic correlations among type traits were lower than the genetic correlations. The highest negative genetic correlation was between rear legs side and rear legs rear (-0·95) and the highest positive correlation between chest width and beef shape (0·93).Genetic correlations between type and production were low to moderate and were similar for milk, fat and protein yields. The genetic correlations between the production traits and chest width, udder depth and beef shape were negative but were positive between production and angularity, rear udder width and teat placement side.

scholarly journals Factor analysis for genetic evaluation of linear type traits in dual-purpose autochthonous breeds

animal ◽  
2016 ◽  
Vol 10 (3) ◽  
pp. 372-380 ◽  
Author(s):  
S. Mazza ◽  
N. Guzzo ◽  
C. Sartori ◽  
R. Mantovani
Keyword(s):  
Factor Analysis ◽  
Genetic Evaluation ◽  
Linear Type ◽  
Dual Purpose ◽  
Type Traits

26 Are Subjectively Scored Linear Type Traits Suitable Predictors of Genetic Merit for Feed Intake in Grazing Holstein-friesian Dairy Cows?

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 17-17
Author(s):  
Maeve Williams ◽  
Craig P Murphy ◽  
Roy D Sleator ◽  
Siobhan C Ring ◽  
Donagh P Berry
Keyword(s):  
Body Weight ◽  
Dairy Cows ◽  
Milk Yield ◽  
Feed Intake ◽  
Mixed Models ◽  
Genetic Correlations ◽  
Linear Type ◽  
Genetic Merit ◽  
Type Traits ◽  
Genetic Evaluations

Abstract Measuring dry matter intake (DMI) in grazing dairy cows using currently available techniques is invasive, time consuming, and expensive. An alternative to directly measuring DMI for use in genetic evaluations is to identify a set of readily available data sources that can be used in a multi-trait genetic evaluation with DMI. The objectives of the present study were to estimate the genetic correlations between readily available body-related linear type trait information and DMI in grazing, lactating Irish dairy cows and to estimate the partial genetic correlations between linear traits and DMI, after adjusting for differences in genetic merit for body weight. After edits, a total of 8,055 test-day records of DMI, body weight, and milk yield from 1,331 multiparous dairy cows were available, as were chest width, body depth, and stature scores for 47,141 first lactation dairy cows. In addition to considering the routinely recorded linear type traits individually, novel traits were defined as the product of two or three linear type traits as an approximation of rumen volume. The genetic variance of DMI, body weight, milk yield, and linear type traits were estimated using univariate animal linear mixed models. Sire linear mixed models were used to calculate genetic and phenotypic covariances. All linear type traits were moderately heritable (0.27 to 0.49) and genetically correlated (0.29 to 0.63) with DMI. The genetic correlations between the individual linear type traits and DMI, when the latter was adjusted for differences in the genetic merit for body weight, varied from 0.00 to 0.39. If the (partial) genetic correlations were validated with genetic evaluations, routinely available linear type trait records and live weight data could facilitate the selection of DMI in dairy cows, removing the need to capture large amounts of cost prohibitive feed intake phenotypes.

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