Developing a genetic evaluation system for milk traits in Russian black and white dairy cattle

Mixed linear models have been applied for predicting breeding values of dairy cattle in most of the developed countries since the 1980s. However, the Russian Federation is still using the old contemporary comparison method. The objective of our study was to develop a best linear unbiased prediction (BLUP) for an animal model of breeding values for the Leningrad region. We tested both a first-lactation model (FLM) and a multi-lactation repeatability model (MLM). The data included milk records of 206 114 cows from 49 herds. Estimated heritabilities from FLM were 0.24, 0.20, and 0.20 for milk, protein, and fat yields, respectively, and 0.18, 0.19, and 0.20 from MLM. Repeatabilities were 0.34 for milk yield and 0.31 for both fat and protein yields. Genetic trends were similar for both models (FLM vs MLM): 59 vs 56 kg year-1 for milk, 1.90 vs 1.84 kg year-1 for fat, and 1.67 vs 1.62 kg year-1 for protein yield during 2000–2016. Based on the difference between the genetic trends in FLM and MLM, the applied BLUP method passed the validation method I by Interbull.

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Lactation curves of Sarda breed goats estimated with test day models

Journal of Dairy Research ◽

10.1017/s0022029905001366 ◽

2005 ◽

Vol 72 (4) ◽

pp. 470-475 ◽

Cited By ~ 11

Author(s):

Nicolò PP Macciotta ◽

Pancrazio Fresi ◽

Graziano Usai ◽

Aldo Cappio-Borlino

Keyword(s):

Milk Production ◽

Milk Yield ◽

Linear Models ◽

Morphological Structure ◽

Production Traits ◽

Mixed Linear Models ◽

Milk Production Traits ◽

Milk Traits ◽

Lactation Stage ◽

Parity Number

Test day records of milk yield (38765), fat and protein contents (11357) of Sarda goats (the most numerous Italian goat breed) were analysed with mixed linear models in order to estimate the effects of test date (month and year of kidding for fat and protein contents) parity, number of kids born, altitude of location of flocks (<200 m asl, 200–500 m asl, >500 m asl), flocks within altitude and lactation stage (eight days-in-milk intervals of 30 d each) on milk production. All factors considered in the models affected milk traits significantly. Milk yield was lower in first parity goats than in higher parities whereas fat and protein contents showed an opposite trend. Goats with two kids at parturition had a higher milk yield than goats with one kid and tended to have lower fat and protein percentages. Repeatability between test days within lactation was 0·34, 0·17 and 0·45 for milk yield, fat content and protein content, respectively. Lactation curves of goats farmed at different altitudes were clearly separated, especially for milk yield. Results of the present study highlight differences in milk production traits among the three subpopulations that have been previously identified within the Sarda breed on the basis of the morphological structure of animals and altitude of location of flocks.

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PSX-19 Factors affecting growth and carcass trait performance of Canadian heavy lambs

Journal of Animal Science ◽

10.1093/jas/skz258.900 ◽

2019 ◽

Vol 97 (Supplement_3) ◽

pp. 457-457

Author(s):

Erin Massender ◽

Luiz Brito ◽

Angela Cánovas ◽

Delma Kennedy ◽

Flavio Schenkel

Keyword(s):

Evaluation System ◽

Fixed Effects ◽

Linear Models ◽

Random Effect ◽

Growth Trait ◽

Carcass Trait ◽

Classification Systems ◽

Carcass Weight ◽

Mixed Linear Models ◽

Factors Affecting

Abstract The profitability of meat lamb production is strongly dependent on growth and carcass trait performance of market lambs. The objective of this research was to test the significance of non-genetic factors on growth, ultrasound, and carcass traits of Canadian heavy lambs. Hot carcass weight (HCW, kg), fat depth at the GR site (FATGR, mm), average carcass conformation score (CONF, points), and total carcass value (PRICE, $CAD) were measured for 8,865 purebred lambs marketed through Quebec’s Heavy Lamb Sales Agency. Corresponding management information and growth trait records for over 19,000 animals with carcass records and their relatives were extracted from the Canadian Sheep Genetic Evaluation System. Single-trait mixed linear models in SAS were used to test the significance (P < 0.05) of various non-genetic effects, after a Scheffe adjustment for multiple comparisons. All models included categorical fixed effects of sex (male or female), breed (Hampshire, HA; Suffolk, SU; Canadian Arcott, CD; Polled Dorset, DP; Rideau Arcott, RI; Polypay, PO), dam age at parity (1 to 7+ years), and birth and rearing type (born as single, twin, or triplet and more, and reared as single or multiple), and a random effect of contemporary group. Linear covariates of slaughter age or carcass weight were included in the carcass trait models, while a scanning weight covariate was used for ultrasound trait models. Male lambs were found to be significantly heavier during growth, had greater HCW and PRICE, and lower FATGR and CONF than female lambs. As expected, terminal breeds (HA, SU, CD) tended to have greater growth, greater HCW and PRICE, and lower FATGR than maternal (DP, RI, RV, PO) breeds. This information could be utilized by Canadian sheep producers to manage their flocks to maximize the revenue of lambs marketed through price grid classification systems.

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Dairy cattle industry and genetic improvement programs in Thailand

Animal Production Science ◽

10.1071/an16454 ◽

2017 ◽

Vol 57 (7) ◽

pp. 1242

Author(s):

Santi Pangmao ◽

Peter C. Thomson ◽

Mehar S. Khatkar

Keyword(s):

Dairy Cattle ◽

Fixed Effects ◽

Genetic Parameters ◽

Fat Percentage ◽

Breeding Values ◽

North East ◽

The North ◽

Breed Group ◽

Improvement Programs ◽

Genetic Trends

The objective of the present study was to estimate genetic parameters and evaluate the genetic trends of 100-day milk yield (MY), fat percentage (FP) and protein percentage (PP) in three government dairy cattle farms in Thailand, located in the north and north-east of the country. The data consisted of records from 1745 first-lactation cows that calved between 1986 and 2015, which were the progeny of 287 sires and 1237 dams. Most of the animals were crossbred Holstein-Friesian with native or zebu animals. The total number of animals in the pedigree was 4753. Univariate and bivariate linear mixed models were used to estimate genetic parameters and breeding values by using ASReml-R. The fixed effects in the model were herd, year of calving, season of calving, breed group and the interaction between year and season of calving, and the random effects were animal and residual. All fixed effects had significant effects on the three traits, except breed group. The estimated heritabilities for MY, FP and PP were 0.242 ± 0.061, 0.066 ± 0.048 and 0.329 ± 0.072 respectively. The genetic correlation for MY and FP, MY and PP, and FP and PP were 0.219 ± 0.352, –0.271 ± 0.177 and 0.452 ± 0.255 respectively. The genetic trends based on estimated breeding values over year of birth did not show consistent improvement in all three traits, although there was a slight declining trend in MY in the later years.

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The Progeny test of Friesian sires for milk traits by using the contemporary comparison method

Revista Colombiana de Ciencia Animal - RECIA ◽

10.24188/recia.v13.n1.2021.747 ◽

2021 ◽

Vol 13 (1) ◽

pp. e747

Author(s):

Omar R Mardenli

Keyword(s):

Milk Fat ◽

Milk Protein ◽

Dairy Farms ◽

Comparison Method ◽

Fat Percentage ◽

Milk Traits ◽

Breeding Values ◽

Holstein Friesian ◽

Genetic And Phenotypic Correlations ◽

Estimated Breeding Values

In this study, the contemporary comparison method (CC) of half-sibs relation was used to estimate the breeding values of Holstein-Friesian sires for 305 -day milk yield (305-DMY) and basic components of milk traits, 409 records of cows that are daughters of ten sires in eight Syrian dairy farms where used. Result of the study showed differences in the estimated breeding values(ccEBVs), where the E Sire achieved the highest value of 305-DMY trait (254.47 kg), while the B Sire achieved the highest value of milk protein percentage (MPP), milk fat percentage (MFP)and milk lactose percentage (MLP) traits (0.822 %, 0.857 %and 1.09% respectively). According to their sires, daughters of E Sire outperformed the counterparts in the 305-DMY (p = 0.001), MPP (p = 0.001) and MFP (p = 0.04) traits (5701.44 kg, 3.55%, and 3.88% respectively). According to source of farm, daughters in Farm 5 achieved the highest value of 305-DMY trait (p=0.04) and daughters in the seventh farm achieved the highest value of MPP trait (p=0.007), the values were 5403.48 kg and 3.54 % respectively. Values of heritability (h2) for the traits of 305-DMY, MPP, MFP and MLP were 0.33,0.54,0.43 and 0.47 respectively. Most of genetic and phenotypic correlations coefficients were approaching to zero except the genetic relation between MLP and MPP and phenotypic relation between MFP and MPP (0.88 and 0.84 respectively).

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Experimental Analysis of Condensation Rate in Conductive Cooling Systems for Dairy Cattle

Applied Engineering in Agriculture ◽

10.13031/aea.12259 ◽

2018 ◽

Vol 34 (2) ◽

pp. 425-436

Author(s):

Kristen Michelle Perano ◽

Timothy J Shelford ◽

Kifle G Gebremedhin

Keyword(s):

Moisture Content ◽

Dairy Cattle ◽

Dairy Cows ◽

Linear Models ◽

Cooling System ◽

Condensation Rate ◽

Mixed Linear Models ◽

Circulating Water ◽

Dewpoint Temperature ◽

Bedding Surface

Abstract. Conductive cooling for dairy cattle is an emerging technology that holds promise as a way of relieving heat stress. A conductive cooling system using modified Dual Chamber Comfort (DCC) waterbeds from Advanced Comfort Technologies as heat exchangers placed in the stalls of dairy cows was tested. Rate of moisture accumulation in two types of bedding (sand and sawdust) was studied for two levels of relative humidity (RH) of air (~60% and ~75%). Four bedding thicknesses were considered in this study and were 0.5, 2.5, 7.5, and 20 cm. The experiment consisted of the following: (1) two waterbeds cooled by circulating water at 4.5°C, and (2) two more waterbeds (control) where the water in the waterbeds was not cooled. Moisture content of the bedding was measured in duplicate at three locations on the surface of each waterbed for each of 20 treatments (sand and sawdust bedding measured at both ~60% RH and ~75% RH and at five bedding thicknesses/sampling depths). The moisture measurements were conducted before and after 2 h of cooling. In cases where the bedding thickness was 2.5 cm or more, the temperature of the bedding was measured at three points using thermocouples: (1) at the surface of the waterbed, (2) at mid depth, and (3) at 0.5 cm below the bedding surface. Mixed linear models were used to calculate the condensation rates and the equilibrium temperatures. In all treatment combinations, the surface temperature of the cooled waterbeds was at least 7.5°C lower than the dewpoint temperature of the air. For the 0.5-cm thick sawdust, condensation rates, calculated in percent increase in dry basis of moisture content per hour (% d.b. h-1), were 3.5% d.b. h-1 higher for the cooled waterbeds than that for the control waterbeds at the ~75% RH. For 0.5-cm thick sawdust at ~60% RH, the condensation rate for the cooled waterbeds was 3.1% d.b. h-1 higher than that for the control waterbeds. Similarly, the condensation rates for the 0.5-cm thick sand were 2.0% d.b. h-1 higher for the cooled waterbeds than for the control waterbeds at the ~75% RH conditions and 1.3% d.b. h-1 higher at the ~60% RH conditions. The condensation rate for the 2.5-cm thick sand bedding measured at the top surface of the waterbed (the bottom 0.5 cm of the bedding) was statistically significant but negligible (0.1% d.b. h-1). No other treatments yielded any difference in condensation rate between the cooled waterbeds and the control waterbeds. Keywords: Animal housing, Bedding thickness, Condensation rate, Conductive cooling, Dairy cows, Stall bedding.

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Use of molecular technologies for the advancement of animal breeding: genomic selection in dairy cattle populations in Australia, Ireland and New Zealand

Animal Production Science ◽

10.1071/an12304 ◽

2013 ◽

Vol 53 (9) ◽

pp. 869 ◽

Cited By ~ 24

Author(s):

Richard J. Spelman ◽

Ben J. Hayes ◽

Donagh P. Berry

Keyword(s):

New Zealand ◽

Dairy Cattle ◽

Evaluation System ◽

Test Results ◽

Genomic Information ◽

Breeding Programs ◽

Breeding Values ◽

Genetic Evaluations ◽

Initial Results ◽

Genomic Predictions

The New Zealand, Australian and Irish dairy industries have used genomic information to enhance their genetic evaluations over the last 2–4 years. The improvement in the accuracy obtained from including genomic information on thousands of animals in the national evaluation system has revolutionised the dairy breeding programs in the three countries. The genomically enhanced breeding values (GEBV) of young bulls are more reliable than breeding values based on parent average, thus allowing the young bulls to be reliably selected and used in the national herd. Traditionally, the use of young bulls was limited and bulls were not used extensively until they were 5 years old when the more reliable progeny test results became available. Using young sires, as opposed to progeny-tested sires, in the breeding program dramatically reduces the generation interval, thereby facilitating an increase in the rate of genetic gain by 40–50%. Young sires have been marketed on their GEBV in the three countries over the last 2–4 years. Initial results show that the genomic estimates were overestimated in both New Zealand and Ireland. Adjustments have since been introduced into their respective national evaluations to reduce the bias. A bias adjustment has been included in the Australian evaluation since it began; however, official genomic evaluations have not been in place as long as in New Zealand and Ireland, so there has been less opportunity to validate if the correction accounts for all bias. Sequencing of the dairy cattle population has commenced in an effort to further improve the genomic predictions and also to detect causative mutations that underlie traits of economic performance.

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Inheritance and Correlation Analysis of Main Agronomic Traits in Mungbean (Vigna radiata L.) by Mixed Linear Models

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2012.00624 ◽

2013 ◽

Vol 38 (4) ◽

pp. 624-631

Author(s):

Chang-You LIU ◽

Bao-Jie FAN ◽

Zhi-Min CAO ◽

Yan WANG ◽

Zhi-Xiao ZHANG ◽

...

Keyword(s):

Correlation Analysis ◽

Vigna Radiata ◽

Linear Models ◽

Agronomic Traits ◽

Mixed Linear Models

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Comparison of models for missing pedigree in single-step genomic prediction

Journal of Animal Science ◽

10.1093/jas/skab019 ◽

2021 ◽

Vol 99 (2) ◽

Author(s):

Yutaka Masuda ◽

Shogo Tsuruta ◽

Matias Bermann ◽

Heather L Bradford ◽

Ignacy Misztal

Keyword(s):

Density Function ◽

Single Step ◽

Joint Density ◽

Pedigree Information ◽

Relationship Matrix ◽

Genomic Information ◽

Breeding Values ◽

Joint Density Function ◽

Information Updates ◽

Genetic Trends

Abstract Pedigree information is often missing for some animals in a breeding program. Unknown-parent groups (UPGs) are assigned to the missing parents to avoid biased genetic evaluations. Although the use of UPGs is well established for the pedigree model, it is unclear how UPGs are integrated into the inverse of the unified relationship matrix (H-inverse) required for single-step genomic best linear unbiased prediction. A generalization of the UPG model is the metafounder (MF) model. The objectives of this study were to derive 3 H-inverses and to compare genetic trends among models with UPG and MF H-inverses using a simulated purebred population. All inverses were derived using the joint density function of the random breeding values and genetic groups. The breeding values of genotyped animals (u2) were assumed to be adjusted for UPG effects (g) using matrix Q2 as u2∗=u2+Q2g before incorporating genomic information. The Quaas–Pollak-transformed (QP) H-inverse was derived using a joint density function of u2∗ and g updated with genomic information and assuming nonzero cov(u2∗,g′). The modified QP (altered) H-inverse also assumes that the genomic information updates u2∗ and g, but cov(u2∗,g′)=0. The UPG-encapsulated (EUPG) H-inverse assumed genomic information updates the distribution of u2∗. The EUPG H-inverse had the same structure as the MF H-inverse. Fifty percent of the genotyped females in the simulation had a missing dam, and missing parents were replaced with UPGs by generation. The simulation study indicated that u2∗ and g in models using the QP and altered H-inverses may be inseparable leading to potential biases in genetic trends. Models using the EUPG and MF H-inverses showed no genetic trend biases. These 2 H-inverses yielded the same genomic EBV (GEBV). The predictive ability and inflation of GEBVs from young genotyped animals were nearly identical among models using the QP, altered, EUPG, and MF H-inverses. Although the choice of H-inverse in real applications with enough data may not result in biased genetic trends, the EUPG and MF H-inverses are to be preferred because of theoretical justification and possibility to reduce biases.

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