scholarly journals Analysis of longevity in the Slovak Pinzgau population – extension to the animal model

2013 ◽  
Vol 58 (No. 7) ◽  
pp. 289-295 ◽  
Author(s):  
G. Mészáros ◽  
O. Kadlečík ◽  
R. Kasarda ◽  
J. Sölkner
Keyword(s):  
Animal Model ◽  
Milk Production ◽  
Fixed Effects ◽  
Herd Size ◽  
Size Change ◽  
Breeding Values ◽  
The Third ◽  
Stage Of Lactation ◽  
Increased Risk ◽  
High Age

Breeding values for length of productive life in Slovak Pinzgau cattle were estimated using survival analysis. As the results were corrected for milk production, the final breeding values represented the ability of cows to avoid culling from reasons other than milk production. In addition to the relative milk yield, the risk of culling was also studied in connection with the herd and year of calving, parity and stage of lactation, herd size change and age at the first calving. Among the fixed effects, the low milk production, high age at the first calving, and decreasing herd size were associated with increased risk of culling. The risk was non-linear for parity &times; stage of lactation classes, decreasing within the first parity and increasing during later parities. Two genetic random effects were considered in separate models: the sire of the cow and the animal itself, both with the corresponding pedigree records up to the third generation. The genetic effects were estimated in separate runs, but the rest of the model remained unchanged. Heritability was h<sup>2 </sup>= 0.08 for sire model, confirming the results of an earlier study in the Slovak Pinzgau population. The computational feasibility of the animal model for estimation of breeding values for cows was confirmed in this study. The new breeding values could be computed for each cow, accounting for all relationships within the population. The estimated heritability for the animal model was h<sup>2 </sup>= 0.11, which should be used later on for animal breeding purposes. &nbsp;

scholarly journals Animal Model Versus Polynomial Legendre Test-Day In Dairy Cattle

2020 ◽  
Vol 23 (1) ◽  
pp. 5-12
Author(s):  
Mircea Cătălin Rotar ◽  
Horia Grosu ◽  
Mihail Alexandru Gras ◽  
Rodica Ştefania Pelmuş ◽  
Cristina Lazăr ◽  
...  
Keyword(s):  
Animal Model ◽  
Dairy Cattle ◽  
Fixed Effects ◽  
Rank Correlation ◽  
Pedigree Information ◽  
Lactation Period ◽  
Data Set ◽  
Breeding Values ◽  
Normal Limits ◽  
Model Versus

AbstractThe aim of the study was to compare the classical animal model (based on total milk for 305 days) with the Test-Day model (using monthly records of milk yield from Official Records of Performances). The data set derived from a total 175 animals (cows with records, parents of these animals and the descendants) from two Romanian breeds (Romanian Black Spotted and Montbeliarde), the phenotypic and the pedigree information arisen from National Research Development Institute for Animal Biology and Nutrition (IBNA-Balotesti). The selection criteria to be included in the analysis for each cow was to have at least 3 test-days and the days in milk between 200 and 330 for the Test-Day model and the total amount of the 305- day lactation yield for classical Animal Model respectively. Both models use B.L.U.P methodology and for that reason all the estimates were adjusted for fixed effects and all the breeding values and the solution for fixed effects were estimated simultaneous. For the animal model the fixed effects used was the breed and the year of performing and for the Test-Day model was an extra one, the test day effect. The correlation calculated between test days was very high (over 90%) for consecutive tests, and was getting lower when the days between tests was higher (under 40%). Also, in terms of heritability the values were in normal limits throughout lactation, except at the beginning and end of lactation period where these values were a little bit higher. The comparison of the ranking of breeding values with Spearman rank correlation shows that in 80% of the cases the ranking was similar for both models. As the ranking correlations shows, it is certain that the two models are very similar when they are used for genetic evaluation. But, in conclusion, we can say that for a better lactation curve estimation it is recommending to use test-day model for dairy cattle.

scholarly journals Definition of subgroups for fixed regression in the test-day animal model for milk production ofHolsteincattle in theCzech Republic

2011 ◽  
Vol 50 (No. 1) ◽  
pp. 7-13 ◽  
Author(s):  
L. Zavadilová ◽  
E. Němcová ◽  
J. Přibyl ◽  
J. Wolf
Keyword(s):  
Animal Model ◽  
Milk Production ◽  
Legendre Polynomials ◽  
Environmental Effect ◽  
Random Regression ◽  
Breeding Values ◽  
Regression Test ◽  
Days Open ◽  
Calving Season ◽  
Definition Of

The investigation was based on roughly 3.9, 2.7 and 1.7 million test-day records from first, second and third lactation, respectively, sampled from 596 200 Czech Holstein cows between the years 1991 and 2002. Breeding values were estimated from multi-lactation random-regression test-day models which contained the fixed effect of herd-test day, fixed regression on days in milk and random regressions on the animal level and the permanent environmental effect. Third degree Legendre polynomials (with four coefficients) were used for both the fixed and random regressions. The models differed in fixed regression. In Analysis I, 96 subclasses were defined according to age at calving, season and year of calving within lactation. In Analysis II, days open were additionally included as a grouping factor resulting in 480 subclasses. Rank correlations over 0.98 between both analyses were observed for breeding values for sires. Grouping according to Analysis I was recommended. &nbsp;

Estimates of heritabilities of Canadian Holstein conformation traits by threshold model

1991 ◽  
Vol 71 (3) ◽  
pp. 629-632 ◽  
Author(s):  
J. Jamrozik ◽  
L. R. Schaeffer ◽  
E. B. Burnside ◽  
B. P. Sullivan
Keyword(s):  
Animal Model ◽  
Em Algorithm ◽  
Variance Components ◽  
Fixed Effects ◽  
Threshold Model ◽  
Model Data ◽  
Stage Of Lactation ◽  
Continuous Scale ◽  
Type Traits ◽  
Holstein Population

Sire variances for 30 conformation traits on Canadian Holsteins were estimated on the underlying continuous scale using a single trait threshold linear model. Data were linearized first classifications on 66 617 cows by 3305 sires, classified since February 1988. The model included a random sire effect and fixed effects of herd-round of classification-classifier, age at classification and stage of lactation at classification. Sires were assumed unrelated in this study. Variance components for sires were estimated by REML EM algorithm. Estimates of heritabilities were generally larger than those currently used in genetic evaluation for type traits in Canadian Holstein population. The new heritabilities are recommended for use in a traditional linear animal model procedure. Key words: Variance components, threshold model, type traits

scholarly journals Effect of Sex of Birth and Stage of Lactation on Milk Production and Its Components in the Holstein-FriesianCows

2018 ◽  
Vol 8 (2) ◽  
pp. 88-91
Author(s):  
Raed Kawkab Al-Muhja
Keyword(s):  
Milk Production ◽  
Milk Fat ◽  
Significant Interaction ◽  
Chemical Components ◽  
College Of Agriculture ◽  
The Third ◽  
Stage Of Lactation ◽  
A Value ◽  
Holstein Friesian ◽  
Main Components

This study was conducted on data which  collected from the filed Cattle in the college  of Agriculture / University of Baghdad for the period from 1/7/2013 to 1/10/2013, which included 28 cows of Holstein Friesian to show the effect of sex of birth and the stage of lactation on Milk production  and  the main components. Our results showed The highest average milk production for female foster cows recorded in the first week with a value of 233L . The results show that had no significant effect  of sex of birth on milk production  and  the main components. The results  showed  that the highest values ​​of milk fat, lactose and minerals in the seventh week of lactation, which values ​​were (3.559, 4.337and 0.638%) respectively, while the highest protein value was recorded in the third week (2.821%). There was no significant interaction  among chemical components  and stage of lactation , despite the superiority of the milk of female foster cows on the milk of male foster cows in some traits

scholarly journals Estimation of genetic parameters and breeding values for litter size in the first three parity of landrace sows

2016 ◽  
Vol 32 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Dragomir Lukac ◽  
Vitomir Vidovic ◽  
Teodora Vasiljevic ◽  
Oliver Stankovic
Keyword(s):  
Animal Model ◽  
Genetic Parameters ◽  
Multivariate Analyses ◽  
Reproductive Traits ◽  
Phenotypic Variance ◽  
Breeding Values ◽  
The Third ◽  
Reproduction Traits ◽  
Genetic And Phenotypic Correlations ◽  
Estimated Breeding Values

The aim of this study was to estimate the genetic parameters and breeding values for reproduction traits of Landrace sows in the first three parities by Animal model. Records of 2238 first parity; 2125 second parity and 1872 third parity Landrace sows farrowing between 2007 and 2012 were included in the analysis. The traits included in the analyses were total pigs born (TB), number of pigs born alive (NBA), number of pigs weaned (NW) and litter weaning weight (LW) in the parities. The genetic parameters were estimated using a multivariate analyses Animal model using REML procedure. Estimates of heritability for TB were 0.03, 0.05 and 0.18, for NBA were 0.04, 0.02 and 0.17, for NW were 0.08, 0.08 and 0.01 and for LW were 0.09, 0.11 and 0.03 for parities 1 to 3. Genetic and phenotypic variance were increased from the first to the third parity. Between the majorities of studied reproductive traits were the recorded positive genetic and phenotypic correlations, except between LW and other analyzed properties where they recorded a high correlation negative in third parity. Means of estimated breeding values of reproductive traits from first parity to third parity was indecreased.

EVALUATION OF DAIRY CATTLE FOR FINAL CLASS USING ANIMAL MODELS

1988 ◽  
Vol 68 (3) ◽  
pp. 639-645 ◽  
Author(s):  
J. JAMROZIK ◽  
L. R. SCHAEFFER
Keyword(s):  
Animal Models ◽  
Dairy Cattle ◽  
Fixed Effects ◽  
Genetic Relationships ◽  
Residual Effects ◽  
Breeding Values ◽  
Stage Of Lactation ◽  
Key Words Animal ◽  
Estimated Breeding Values ◽  
Genetic Evaluations

Estimated breeding values for final class of 364 868 Canadian Holstein Friesian cows and 10 186 bulls from three different animal models were compared. FIRST lactation, first classifications were described by a model with fixed effects of herd-round-classifier, linear and quadratic effects of age at calving and stage of lactation at classification, and random effects of additive genetic effects of cows, and residual effects. All additive genetic relationships among animals were included. A second model used the LATEST classification on each cow rather than the first and these observations were pre-adjusted for age and stage. The third model used ALL classifications on each cow, and these were also pre-adjusted for age and stage effects. Correlations among estimated breeding values between methods ranged from 0.92 to 0.95. Estimated breeding values from LATEST were most highly correlated to sire proofs from the currently official sire model which also used the latest classification of each cow. Correlations of estimated breeding values between sires and their sons showed that results from LATEST were more accurate than results from the other two models. A model similar to that for LATEST is proposed for official genetic evaluations for conformation in the Canadian Holstein population. Key words: Animal model, conformation, dairy cattle

scholarly journals 182 The effect of previous lactation milk production on twinning prevalence in US dairy cows

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 134-135
Author(s):  
Rachel Schambow ◽  
Thomas B Bennett ◽  
Dorte Dopfer ◽  
Joao Paulo N Martins
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Fixed Effects ◽  
Herd Size ◽  
Clear Trend ◽  
Data Set ◽  
Interaction Terms ◽  
Lactating Dairy Cows ◽  
Final Data ◽  
Using Data

Abstract The present study aimed to identify associations with previous lactation production on twinning prevalence in US dairy farms using data comprising over 7.9 million dairy calving and production records from 827 herds between 2001 and 2020. Inclusion criteria were breed (Holstein, Jersey, dairy and mixed cross), herd size (&gt; 50 calvings/year), and 305-d milk production &gt; 3,182 kg (7,000 lbs). Cows without previous production information or calving date were removed from the final data set, including all first lactation cows. Parity was grouped into 2 and 3+. Final data included n = 2,894,163 records from 2009 to 2020 from 577 herds in 24 states with average herd size from 50 to 14,948 calvings/year. Data were analyzed by logistical regression using the GLIMMIX procedure of SAS with herd within state as random effects. Absolute 305-d milk production from each cow’s previous lactation, parity, breed, calving month, year, calving interval (CI), and interaction terms of production by parity, production by breed, CI by parity, and CI by breed were used as predictors for next lactation twinning prevalence. All fixed effects were significantly associated with the outcome (P &lt; 0.001). Twinning prevalence was increased for higher levels of milk production within parity 2 and 3+ (OR: 1.067, 1.064; CL: 1.057–1.078, 1.054–1.075), and within Holstein, Jersey, mixed crossbreed, and dairy crossbreed (OR: 1.042, 1.068, 1.085, 1.07; CL: 1.038–1.046, 1.053–1.082, 1.056–1.114, 1.051–1.09). Parity 3+ had increased twinning compared to parity 2 (OR: 1.497; CL: 1.478–1.517). Holsteins had increased twinning compared to Jerseys (OR: 1.466, CL: 1.394–1.542). Year showed no clear trend. Twinning was increased for calving in spring/summer (April-September) with peak in June and July (OR: 1.377, 1.374; CL: 1.346–1.409, 1.344–1.405), correlating to conception months of September and October. These data can be instrumental to guide research focus and producer decisions to reduce twin births in lactating dairy cows.

scholarly journals Genetic evaluation for longevity of Croatian Simmental bulls using a piecewise Weibull model

2013 ◽  
Vol 56 (1) ◽  
pp. 89-101
Author(s):  
S. Jovanovac ◽  
N. Raguž ◽  
J. Sölkner ◽  
G. Mészáros
Keyword(s):  
Milk Production ◽  
Weibull Model ◽  
Fixed Time ◽  
Herd Size ◽  
Genetic Evaluation ◽  
Genetic Trend ◽  
Data Set ◽  
Breeding Values ◽  
Age At First Calving ◽  
Productive Life

Abstract. Genetic evaluation of sires for functional longevity was conducted using survival analysis techniques. The data set consisted of 49 659 Simmental cows with first calving from 1997 to 2008. A piecewise Weibull sire model was used to estimate breeding values of 251 bulls for functional length of productive life of their daughters. The model was stratified by parity i.e. a separate baseline hazard was computed for each stratum. Besides the random sire effect, the model included the fixed time independent effects of age at first calving, herd size and region as well as the time dependent effects of relative milk production and year*season of first calving. The highest impact on longevity was found for relative milk production. Cows with the lowest milk yields were at approximately 2.7 times higher risk of culling compared to cows with average milk production. Effects of age at first calving, herd size and country region had lower impact on longevity. Sire variance was 0.023 which results in a heritability of 0.06 for functional length of productive life. The average approximate reliability of estimated breeding values was 0.49. Genetic trend showed no clear tendency by year of birth of bulls.

scholarly journals  Estimation of genetic parameters and evaluation of test-day milk production in sheep

2012 ◽  
Vol 57 (No. 11) ◽  
pp. 522-528 ◽  
Author(s):  
J. Bauer ◽  
M. Milerski ◽  
J. Přibyl ◽  
L. Vostrý
Keyword(s):  
Milk Production ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Least Squares Method ◽  
Coefficient Of Determination ◽  
Suitable Model ◽  
Breeding Values ◽  
Parity Number ◽  
Daily Milk Production ◽  
Daily Milk

&nbsp;Genetic parameters and breeding values were estimated based on 11 708 daily milk yields from 2255 lactations (1351 sheep, 19 different flocks) between the years 2004 and 2010. The pedigree covered 2334&nbsp;individuals, including both the recorded animals and their known ancestors. The fixed effects were estimated by the least-squares method, while the genetic parameters were estimated by the REML method. The data were tested by 49 models, but on the basis of the coefficient-of-determination value and the significance of the effects, only 10 models were used for REML analysis. The most suitable model was chosen on the basis of the breeding values distribution and the heritability of daily milk production, which was estimated at 0.28. The fixed effects of the flock parity number, the flock test day, and the linear and quadratic coefficients of flock&rsquo;s days-in-milk in the chosen model were all highly significant (P &lt; 0.0001) for the test-day milk yield. The breeding values had a normal distribution and a standard deviation of 0.46 kg. &nbsp;

scholarly journals Genetic parameter of birth and weaning weights for Friesian calves by using an animal model

2005 ◽  
Vol 48 (3) ◽  
pp. 261-269 ◽  
Author(s):  
H. Atil ◽  
A. S. Khattab ◽  
L. Badawy
Keyword(s):  
Animal Model ◽  
Birth Weight ◽  
Fixed Effects ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Likelihood Method ◽  
Multiple Trait ◽  
Breeding Values ◽  
Heritability Estimates ◽  
Maternal Heritability

Abstract. Birth and weaning weights of 556 Friesian calves by 41 sires out of 318 different dams over a 11 years period were obtained from a herd of Friesian in Sakha Experimental Farm, Ministry of Agriculture, Egypt were used. The records were analyzed by Multiple Trait Likelihood Method (MTDFREML) by using a repeatability animal model (BOLDMAN et al., 1995). Convergence was attained after 699 iterations. The fixed effects included in the model were season and year of calving, parity and sex and the random effects were direct and maternal genetic, permanent maternal environmental and error. Direct heritability estimates for birth weight (BW) and weaning weight (WW) are 0.28 and 0.13, respectively, while, maternal heritability estimates for the same traits are 0.14 and 0.06, respectively. Repeatability estimates are 0.75 and 0.15 for BW and WW, respectively. Phenotypic and genetic correlations are 0.89 and 0.80, respectively. Estimates of calve breeding values ranged from −3.12 to 4.11 kg for BW and ranged from −4.10 to 5.11 kg for WW. Sire breeding values ranged from −3.40 to 2.99 kg for BW and ranged from −2.50 to 4.47 kg for WW. Dam breeding values ranged from −6.80 to 5.54 kg for BW and ranged from -6.10 to 6.39 kg for WW.

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