scholarly journals Esmer Sığırlarda Süt Verimine Etkili Çevre Faktörleri ile Fenotipik, Genetik ve Çevresel Yönelimler ve Bazı Genetik Parametrelerin Belirlenmesi

2016 ◽  
Vol 4 (1) ◽  
pp. 41 ◽  
Author(s):  
Muhammet Hanifi Selvi ◽  
Mete Yanar
Keyword(s):  
Environmental Factors ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Trend ◽  
Factors Affecting ◽  
Agricultural College ◽  
Package Program ◽  
Calving Season ◽  
Estimated Breeding Values ◽  
Genetic Trends

In this study, genetic parameters, macro environmental factors and genetic, phenotypic and environmental trends for actual and 305 day milk yield of Brown Swiss cattle reared in Research Farm of Agricultural College at Atatürk University were estimated. Estimated breeding values that were used for calculation of the genetic trend and genetic parameters were estimated by using MTDFREML computer package program. Environmental factors affecting on actual and 305day milk yields were analysed by using Harvey statistic package program. While effects of the years and parities on the actual and 305-day milk yields were highly significant, the influence of the calving season was found to be insignificant. Environmental and phenotypic trends for actual and 305-day milk yields were determined as -33.2 kg and -29.0 kg; and -27.8±19.1 kg/year and -25.9±8.7 kg/year respectively. Genetic trends for actual and 305-day milk yields were calculated as 5.4±3.8 kg and 3.1±3.4 kg. Heritability’s for actual and 305-day milk yields were 0.21±0.12 and 0.16±0.14 respectively. Repeatability values for actual and 305-day milk yield were found as 0.29 and 0.33 respectively.

scholarly journals Genetic parameters and trends for reproductive traits in Blanco Orejinegro cattle from Colombia

2021 ◽  
Vol 42 (4) ◽  
pp. 2523-2538
Author(s):  
Sindy Liliana Caivio-Nasner ◽  
◽  
Albeiro López-Herrera ◽  
Luis Gabriel González-Herrera ◽  
Juan Carlos Rincón Flórez ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Genetic Parameters ◽  
Environmental Influence ◽  
Cattle Breed ◽  
Heritability Estimate ◽  
Reproductive Traits ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Estimated Breeding Values ◽  
Genetic Trends

The Colombian creole cattle breed Blanco Orejinegro (BON) is an important zoogenetic resource, but there is little knowledge about the genetic parameters and trends of its reproductive traits. Therefore, the aim of this study was to estimate parameters for the reproductive traits calving interval (CI), age at first calving (AFC), gestation duration (GD) and genetic trends for CI in the BON breed. Genealogy information from 7,799 animals was used, and employing the MTDFREML program, the components of the variance, heritability (h2), repeatability (rep), and estimated breeding values (EBV) for CI (n=3308), AFC (n=729), and GD (n=306) were estimated, in addition to the inbreeding coefficient (F) of the population. Genetic trends were established through linear regression using R software. Finally, the animals were classified as inbred (F > 0) and noninbred (F=0), and the effect of inbreeding on reproductive performance was established through a generalized linear model using the R program. An average F value of 4.41%±0.06 was observed. The h2 for CI was 0.11±0.03 with a rep of 0.15±0.04; for AFC, h2 was 0.00±0.05; and for GD, h2 was 0.00±0.08. The genetic trend for CI was -0.01 days/year. Finally, for CI, inbreeding depression was evident; this trait increased when inbreeding increased. These results indicate an important environmental influence on reproductive traits. The heritability estimate for CI suggests that little genetic progress could be achieved through selection. The evidence of inbreeding depression raises the need to control inbreeding to conserve this genetic resource.

Genetic and environmental factors affecting some measures of yield and fertility in a registered Canadian Holstein dairy herd in Iran

2002 ◽  
Vol 2002 ◽  
pp. 190-190
Author(s):  
Ali Toosi
Keyword(s):  
Environmental Factors ◽  
Genetic Parameters ◽  
Dairy Herd ◽  
Cattle Breeding ◽  
Factors Affecting ◽  
Lactation Curve ◽  
Dairy Cattle Breeding ◽  
Important Trait ◽  
Genetic And Environmental Factors ◽  
Production Characteristics

Milk production is the most important trait in dairy cattle breeding. Measures of additional traits are also important. Traits of lactation curve are important in their relation to production characteristics. The two major reasons for which dairy cows are disposed are fertility problems and low milk yield (Hansen et al.,1983). The objectives of this study were 1) To evaluate effects of some environmental factors on some measures of yield and fertility, and 2) To estimate genetic parameters for these traits applying REML procedures under sire model.

scholarly journals Environmental Factors and Genetic Parameters of Beef Traits in Fleckvieh Cattle Using Field and Station Testing

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2159
Author(s):  
Radek Filipčík ◽  
Daniel Falta ◽  
Tomáš Kopec ◽  
Gustav Chládek ◽  
Milan Večeřa ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Genetic Correlation ◽  
Genetic Parameters ◽  
The Body ◽  
Carcass Weight ◽  
Genetic Trend ◽  
Meat Yield ◽  
Dual Purpose Cattle ◽  
Genetic And Environmental Factors ◽  
Daily Gain

The goal of this study was to analyze the genetic and environmental factors of selected meat yield indicators in Fleckvieh cattle in the Czech Republic, through the application of station (S) and field (F) testing methods. Data collected from fattened bulls were analyzed for F (n = 9378) and for S (n = 6346). In the F method and the S method, the values of the main meat yield indicators were as follows: carcass weight 402.91 kg (F), 339.37 kg (S); carcass daily gain 626.05 g/day (F), 609.74 g/day (S); SEUROP carcass classification 2.73 (F), 2.19 (S). Environmental factors were found to have a significant impact on the selected meat yield indicators; their heritability ranged from 0.14 (SEUROP classification) to 0.33 (dressing percentage). The genetic trend was significantly positive only in relation to those meat yield traits, which had a positive link to the size or weight of the animal. The genetic correlation between observations obtained in the S and F methods of testing was very high in relation to the carcass daily gain (0.8351) and carcass weight (0.8244), while slightly lower correlations were calculated for the SEUROP classification. A genetic evaluation of the degree of fatness is not routinely performed in Fleckvieh populations, and the newly established heritability for this trait ranges between 0.17–0.20. The genetic correlation between beef yield indicators and the exterior trait of muscularity was also established, and shows a strong link to the net daily gain, the SEUROP classification and body weight (0.79–0.97). The aim of the study was to evaluate the genetic and environmental effects on meat yield and also estimate genetic parameters for new traits. We can also state, based on the results, that a strong positive genetic trend is confirmed, especially in traits related to the size or weight of animals. This result can be used in breeding programs of dual-purpose cattle, where we can genetically improve the meat and milk yield through the body size.

scholarly journals AlphaPart—R implementation of the method for partitioning genetic trends

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Jana Obšteter ◽  
Justin Holl ◽  
John M. Hickey ◽  
Gregor Gorjanc
Keyword(s):  
Genetic Gain ◽  
R Package ◽  
Breeding Programme ◽  
Genetic Trend ◽  
Breeding Values ◽  
Poultry Breeding ◽  
Breeding Programmes ◽  
Estimated Breeding Values ◽  
The Relationship ◽  
Genetic Trends

Abstract Background In this paper, we present the AlphaPart R package, an open-source implementation of a method for partitioning breeding values and genetic trends to identify the contribution of selection pathways to genetic gain. Breeding programmes improve populations for a set of traits, which can be measured with a genetic trend calculated from estimated breeding values averaged by year of birth. While sources of the overall genetic gain are generally known, their realised contributions are hard to quantify in complex breeding programmes. The aim of this paper is to present the AlphaPart R package and demonstrate it with a simulated stylized multi-tier breeding programme mimicking a pig or poultry breeding programme. Results The package includes the main partitioning function AlphaPart, that partitions the breeding values and genetic trends by pre-defined selection paths, and a set of functions for handling data and results. The package is freely available from the CRAN repository at http://CRAN.R-project.org/package=AlphaPart. We demonstrate the use of the package by partitioning the nucleus and multiplier genetic gain of the stylized breeding programme by tier-gender paths. For traits measured and selected in the multiplier, the multiplier selection generated additional genetic gain. By using AlphaPart, we show that the additional genetic gain depends on accuracy and intensity of selection in the multiplier and the extent of gene flow from the nucleus. We have proven that AlphaPart is a valuable tool for understanding the sources of genetic gain in the nucleus and especially the multiplier, and the relationship between the sources and parameters that affect them. Conclusions AlphaPart implements the method for partitioning breeding values and genetic trends and provides a useful tool for quantifying the sources of genetic gain in breeding programmes. The use of AlphaPart will help breeders to improve genetic gain through a better understanding of the key selection points that are driving gains in each trait.

scholarly journals AlphaPart - R implementation of the method for partitioning genetic trends

2020 ◽  
Author(s):  
Jana Obšteter ◽  
Justin Holl ◽  
John M. Hickey ◽  
Gregor Gorjanc
Keyword(s):  
Gene Flow ◽  
Open Source ◽  
Open Source Software ◽  
Genetic Gain ◽  
R Package ◽  
Genetic Trend ◽  
Breeding Values ◽  
Breeding Programmes ◽  
Estimated Breeding Values ◽  
Genetic Trends

AbstractBackgroundIn this paper we present the AlphaPart R package, an open-source software that implements a method for partitioning breeding values and genetic trends to identify sources of genetic gain. Breeding programmes improve populations for a set of traits, which can be measured with a genetic trend calculated from averaged year of birth estimated breeding values of selection candidates. While sources of the overall genetic gain are generally known, their realised contributions are hard to quantify in complex breeding programmes. The aim of this paper is to present the AlphaPart R package and demonstrate it with a simulated pig breeding example.ResultsThe package includes the main partitioning function AlphaPart, that partitions the breeding values and genetic trends by analyst defined paths, and a set of functions for handling data and results. The package is freely available from CRAN repository at http://CRAN.R-project.org/package=AlphaPart. We demonstrate the use of the package by examining the genetic gain in a pig breeding example, in which the multiplier achieved higher breeding values than the nucleus for traits measured and selected in the multiplier. The partitioning analysis revealed that these higher values depended on the accuracy and intensity of selection in the multiplier and the extent of gene flow from the nucleus. For traits measured only in the nucleus, the multiplier achieved comparable or smaller genetic gain than the nucleus depending on the amount of gene flow.ConclusionsAlphaPart implements a method for partitioning breeding values and genetic trends and provides a useful tool for quantifying the sources of genetic gain in breeding programmes. The use of AlphaPart will help breeders to better understand or improve their breeding programmes.

scholarly journals Estimation of genetic parameters and trends for energy-corrected 305-d milk yield in Iranian Holsteins

2012 ◽  
Vol 55 (5) ◽  
pp. 420-426
Author(s):  
N. G. Hossein-Zadeh
Keyword(s):  
Animal Models ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Physiological Mechanism ◽  
Animal Breeding ◽  
Dairy Herds ◽  
Breeding Values ◽  
Estimation Of Genetic Parameters ◽  
Genetic Trends

Abstract. Calving records from the Animal Breeding Centre of Iran collected from January 1995 to December 2007 and comprising 217973 calving events of Holsteins from 704 dairy herds were analysed using univariate and bivariate linear animal models to estimate heritabilities and genetic correlations for energy-corrected 305-d milk yield (ECM) in the first three lactations of Holstein cows. Genetic trends were obtained by regressing yearly mean estimates of breeding values on calving year. Average ECM increased from parity 1 through parity 3. Estimates of heritabilities were from 0.14 to 0.21 for ECM and decreased over the parities. The greatest genetic correlations were between ECM2 and ECM3 (0.96), and the greatest phenotypic correlations were between ECM1 and ECM2 (0.57) and ECM2 and ECM3 (0.57). The high and positive genetic correlations between ECM traits at different lactations are evidence for common genetic and physiological mechanism controlling these traits. There were positive and increasing phenotypic and genetic trends for ECM over the years (P<0.001). Higher heritability of the ECM in the first parity along with the high genetic correlations between first-lactation ECM with these traits in other lactations shows that higher potential exists for selecting animals for ECM based on their first parity records.

scholarly journals Effect of genetic and environmental factors on the phenotype characteristics of lambs

2015 ◽  
Vol 31 (2) ◽  
pp. 223-233 ◽  
Author(s):  
M.P. Petrovic ◽  
Caro Petrovic ◽  
D. Ruzic-Muslic ◽  
N. Maksimovic ◽  
M.M. Petrovic ◽  
...  
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Statistical Analysis ◽  
Environmental Factors ◽  
Weaning Weight ◽  
Average Birth Weight ◽  
Factors Affecting ◽  
Package Program ◽  
The Difference ◽  
Genetic And Environmental Factors

The aim of this study was to determine the influence of environmental factors affecting body weight variability of lambs in two crossbreed groups: Pirot x W?rttemberg and Sjenica x W?rttemberg. Both populations were managed under the same farm conditions. The data were analyzed to determine the effect of age of the dam, weight of dam, birth type, sex, year and season, on the birth weight and weaning weight of crossbreed lambs. Statistical analysis was performed by GLM procedure using the SPSS statistical package program. The average birth weight of Pirot x W?rttemberg lambs was 3.56 kg while Sjenica x W?rttemberg lambs was slightly higher at 3.69 kg. The difference on birth weight between the two crosses was not statistically significant (P>0.05). The average weaning weight of Pirot x W?rttemberg lambs was 23.54 kg while Sjenica x W?rttemberg lambs had higher weight at 24.37 kg. The difference of 0.83 kg on weaning weight was statistically significant (P <0.05). Body weight, depending on the environmental factors, ranged from 3.17 to 3.96 kg at birth and from 22.12 to 24.18 kg at weaning in Pirot x W?rttemberg lambs. Body weight of Sjenica x W?rttemberg lambs ranged from 3.39 to 3.99 kg at birth and from 22.69 to 25.44 kg at weaning. Statistical analysis showed that the differences were statistically significant (P<0.05) and highly significant (P<0.01).

Genetic perspective of milk yield persistency in the first three lactations of Iranian buffaloes (Bubalus bubalis)

2017 ◽  
Vol 84 (4) ◽  
pp. 434-439 ◽  
Author(s):  
Navid Ghavi Hossein-Zadeh ◽  
Mohammad Ali Nazari ◽  
Abdol Ahad Shadparvar
Keyword(s):  
Milk Yield ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Bubalus Bubalis ◽  
Random Regression ◽  
Genetic Trend ◽  
Breeding Center ◽  
Regression Test ◽  
The Difference ◽  
Estimated Breeding Values

The objectives of this study were to estimate the genetic parameters and genetic trends for different measures of persistency (PM) for milk yield in Iranian buffaloes using a random regression test day model. Test day records of the first three lactations of buffaloes within 715 herds comprising 43 014, 38 941 and 33 937 records, respectively, were obtained from the Animal Breeding Center of Iran during 1992 to 2012. Legendre polynomial functions were chosen to fit the lactation curves in the framework of a random regression test day model for estimating (co)variance components. Three measures of persistency were modified based on the lactation curve conditions of buffaloes: (1) The average of estimated breeding values (EBVs) for test day milk yields from day 226 to day 270 as a deviation from the average of EBVs from day 44 to day 62 (PM1), (2) A summation of contribution for each day from day 53 to day 247 as a deviation from day 248 (PM2), (3) The difference between EBVs for day 257 and day 80 (PM3). The highest heritability estimates were observed for PM2over the first three lactations (0·29, 0·80 and 0·42, respectively). Estimates of genetic correlations between persistency measures and milk yield varied from −0·48 to 0·29 (first lactation), from −0·12 to 0·48 (second lactation), and from −0·62 to 0·63 (third lactation). Estimate of genetic trend for first lactation PM2was negative (−0·0088 ± 0·0043;P< 0·05). It is essential to include milk yield persistency in the breeding goal of Iranian buffaloes along with other important traits such as milk yield or reproductive traits.

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