• Animal Bioscience
• /
• 제37권4호
• /
• pp.555-566
• /
• 2024

Objective: This study aimed to assess the genetic parameters and accuracy of genomic predictions for twenty-four linear body conformation traits and overall conformation scores in Korean Holstein dairy cows. Methods: A dataset of 2,206 Korean Holsteins was collected, and genotyping was performed using the Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The traits investigated included body traits (stature, height at front end, chest width, body depth, angularity, body condition score, and locomotion), rump traits (rump angle, rump width, and loin strength), feet and leg traits (rear leg set, rear leg rear view, foot angle, heel depth, and bone quality), udder traits (udder depth, udder texture, udder support, fore udder attachment, front teat placement, front teat length, rear udder height, rear udder width, and rear teat placement), and overall conformation score. Accuracy of genomic predictions was assessed using the single-trait animal model genomic best linear unbiased prediction method implemented in the ASReml-SA v4.2 software. Results: Heritability estimates ranged from 0.10 to 0.50 for body traits, 0.21 to 0.35 for rump traits, 0.13 to 0.29 for feet and leg traits, and 0.05 to 0.46 for udder traits. Rump traits exhibited the highest average heritability (0.29), while feet and leg traits had the lowest estimates (0.21). Accuracy of genomic predictions varied among the twenty-four linear body conformation traits, ranging from 0.26 to 0.49. The heritability and prediction accuracy of genomic estimated breeding value (GEBV) for the overall conformation score were 0.45 and 0.46, respectively. The GEBVs for body conformation traits in Korean Holstein cows had low accuracy, falling below the 50% threshold. Conclusion: The limited response to selection for body conformation traits in Korean Holsteins may be attributed to both the low heritability of these traits and the lower accuracy estimates for GEBVs. Further research is needed to enhance the accuracy of GEBVs and improve the selection response for these traits.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권11호
• /
• pp.1527-1530
• /
• 2002

Factor analysis was applied to the phenotypic correlation matrix of 15 linear type traits (scored linearly 1 to 50 points) for 2035 Holstein cows of 38 sires computed from data collected between 1988 and 1992 in Beijing Shuangqiao Farm and Beijing Xijiao Farm. The 15 linear type traits were stature, body strength, body depth, dairy form, rump angle, rump length, rump width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth and teat placement rear view. The first four components accounted for 49.1% of the total variance in type scores. Factor 1 reflected strong cows, with deep bodies, with long and wide rumps, and tall in stature. Factor 2 reflected cows with well attached fore udders, wide rear udders and whose udders were supported by strong suspensory ligaments with close teat placement. Factor 3 reflected cows with good dairyness, sickled in the hocks, high rear udders and udder floors above the hocks. Factor 4 reflected cows with sloping rumps from hooks to pins and with steep foot angle. Principal component and factor analyses are useful to clarify the relationships among type traits.

• Journal of Animal Science and Technology
• /
• 제52권6호
• /
• pp.467-473
• /
• 2010

A total of 4,323,781 records for informal 16 primary linear descriptive traits of dairy cows in Holstein breed from 1988 to 2007 in USA were analyzed to estimate adjustment factors for lactation number and stage. While all factors in the model were highly significant (P < 0.01), major influences on linear type traits were due to lactation number and stage. The frequencies of lactation number 1 through 6 were 58.6, 22.0, 11.8, 4.8, 2.1, and 0.8%, respectively. Further, the frequencies of lactation stage were 0.7, 76.9, 15.3, 4.9, and 2.1%, respectively, for springing, early, medium, late, and dry. To adjust 16 linear traits (stature, dairy form, strength, body depth, rump width, rump angle, legs rear view, leg set, foot angle, fore udder, rear udder height, rear udder width, udder support, udder depth, and front teat placement), additive and multiplicative adjustment factors of lactation number (lactations 2 to 4) and stage (springing, medium, late and dry) were estimated with the solutions in the generalized linear model, assigning lactation 1 and stage early as base class. Additive adjustment factors of lactation number ranged from -1.23 to 2.908, while multiplicative factors ranged from 0.853 to 2.207. Further, additive and multiplicative adjustment factors for lactation stage ranged from -0.668 to 0.785, and from 0.891 to 1.154. Application of adjustment factors to 20 randomly sampled sub-data sets produced the results that additive adjustment factors for both lactation number and stage reduced more mean square of lactation number and stage over 16 linear traits than any combination of adjustments, and leaded additive adjustment factors for both lactation number and stage as a choice of methods for adjustment of informal 16 primary linear type traits collected by classifiers of AI studs.

• Asian-Australasian Journal of Animal Sciences
• /
• 제28권9호
• /
• pp.1259-1265
• /
• 2015

The present study was performed to study the genetic relationship of productive life with production and type traits of Korean Holsteins at first three lactations. The data for the analysis from 56,054, 28,997, and 11,816 animals of first, second and third parity cows which were born from 2006 to 2011 were collected by Dairy Cattle Improvement Center, National Agricultural Co-operative Federation. Milk, protein and fat yields adjusted for 305 days and average somatic cell score considered as production traits and analyzed type traits were stature, strength, body depth, dairy form, rump angle, rump width, rear leg side view, foot angle, front attachment placement, rear attachment height, rear attachment width, udder cleft, udder depth, front teat placement and front teat length. A multi trait genetic analysis was performed using Wombat program with restricted maximum likelihood animal model composed of fixed effect of birth year, farm and the random effect of animal and random residual effect according to the traits. Heritability estimates of productive life were between 0.06 and 0.13. Genetic and phenotypic correlations between production and productive life traits ranged from 0.35 to 0.04 for milk, 0.16 to 0.05 for protein and 0.18 to 0.02 f 15-0034 (2nd) 150520 or fat. Somatic cells score showed a negative genetic and phenotypic correlation with productive life and also udder type traits, indicating that the selection for higher udder traits will likely to improve resistance to mastitis and persistence in the herd. Among all dairy form type traits, udder characters such as udder cleft showed a significant relationship with productive life. However, a specific change of heritabilities or correlations were not observed with the change of parity. Moreover, further studies are needed to further confirm the significance of the above traits and the effect of parity on above relationships in order to minimize both voluntary and involuntary culling rates while improving herd health and maintaining high yielding dairy cows.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권6호
• /
• pp.784-790
• /
• 2014

In this study we aimed to evaluate the reduction in dimensionality of 20 linear type traits and more final score in 14,943 Holstein cows in Brazil using factor analysis, and indicate their relationship with longevity and 305 d first lactation milk production. Low partial correlations (-0.19 to 0.38), the medium to high Kaiser sampling mean (0.79) and the significance of the Bartlett sphericity test (p<0.001), indicated correlations between type traits and the suitability of these data for a factor analysis, after the elimination of seven traits. Two factors had autovalues greater than one. The first included width and height of posterior udder, udder texture, udder cleft, loin strength, bone quality and final score. The second included stature, top line, chest width, body depth, fore udder attachment, angularity and final score. The linear regression of the factors on several measures of longevity and 305 d milk production showed that selection considering only the first factor should lead to improvements in longevity and 305 milk production.

• Journal of Animal Science and Technology
• /
• 제50권3호
• /
• pp.285-292
• /
• 2008

본 연구는 국제적인 경쟁력을 갖기 위한 젖소개량방법으로 체세포를 활용하는 방법을 모색하고자 선형심사 자료에서 유방염에 관련된 형질을 이용하여 새로운 선발지수를 개발하기 위한 단계로 국내 젖소집단의 체세포점수 분포와 변화추이를 분석해보고 연령, 분만계절, 비유단계의 환경효과를 구명하고 유방관련 형질과의 유전상관과 유전력을 구하여 기초자료로 활용하고자 본 연구를 진행하였다. 분석은 유우군 능력검정을 통하여 2000년부터 수집된 자료를 이용하였고 자료는 1산차 기록을 갖는 10,929개체의 290,144 검정일 기록과 37,723개의 유방형질 기록을 이용하였다. 분석에 이용된 유방형질은 전유방붙음성, 뒷유방높이, 뒷유방너비, 유방깊이, 앞유두길이의 형질이며 체세포 점수간의 표현형상관과 유전상관을 구하고 분산성분을 추정하였으며 개체모형을 이용하여 표현형상관과 유전상관을 분석하였다. 분석에 이용된 모형은 개체모형으로 DF-REML방식을 이용하여 추정하였고 유방깊이와 앞유두길이의 유전력은 0.23, 0.22로 체세포점수의 유전력은 0.08로 분석되었다. 유방형질과 체세포점수간의 표현형상관은 －0.03~－0.06으로 낮게 나타났으며 높은 유방붙음성을 갖을수록 낮은 체세포점수를 보였다. 체세포점수와 유방깊이, 체세포점수와 앞유두길이의 유전상관은 부의 상관을 보였다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권11호
• /
• pp.1514-1524
• /
• 2011

A total of 4,752 monthly lactation records of Friesian cows during the period from 2000 to 2005 were used to estimate genetic parameters and to determine the effect of udder health on milk production traits. Three milk production traits were studied: 305-day milk yield (305-dMY), 305-day fat yield (305-dFY) and 305-day protein yield (305-dPY). Four udder health traits were studied: somatic cell count (SCC), mastitis (MAST), udder health status (UDHS) with 10 categories and udder quarter infection (UDQI) with 7 categories. Mixed model least square analysis was used to estimate the fixed effects of month and year of calving and parity (P) on different studied traits. Sire and dam within sire were included in the model as random effects. Data were analyzed using Multi-trait Derivative Free Restricted Maximum Likelihood methodology (MTDFREML) to estimate genetic parameters. Unadjusted means of 305-dMY, 305-dFY, 305-dPY and SCC were 3,936, 121, 90 kg and 453,000 cells/ml, respectively. Increasing SCC from 300,000 to 2,000,000 cells/ml increased UDQI from 5.51 to 23.2%. Losses in monthly and lactationally milk yields per cow ranged from 17 to 93 and from 135 to 991 kg, respectively. The corresponding losses in monthly and lactationally milk yields return per cow at the same level of SCC ranged from 29.8 to 163 and from 236 to 1,734 Egyptian pounds, respectively. Heritability estimates of 305-dMY, 305-dFY, 305-dPY, SCC, MAST, UDHS, UDQI were 0.31${\pm}$0.4, 0.33${\pm}$0.03, 0.35${\pm}$0.05, 0.23${\pm}$0.02, 0.14${\pm}$0.02, 0.13${\pm}$0.03, and 0.09${\pm}$0.01, respectively. All milk production traits showed slightly unfavorable negative phenotypic and genetic correlations with SCC, MAST, UDHS and UDQI. There were positive and high genetic correlations between SCC and each of MAST (0.85${\pm}$0.7), UDHS (0.87${\pm}$0.10) and UDQI (0.77${\pm}$0.06) and between MAST and each of UDHS (0.91${\pm}$0.11) and UDQI (0.83${\pm}$0.07). It could be concluded that the economic losses from mastitis and high SCC are considerable. The high genetic correlation between SCC and clinical mastitis (CM) suggest that the selection for lower SCC would help to reduce or eliminate the undesirable correlated responses of clinical mastitis associated with selection for increasing milk yield. Additionally, it is recommended also that if direct information on under health traits is not available, measures of SCC can be inclusion in a selection criteria to improve the income from dairy cows.

• Journal of Animal Science and Technology
• /
• 제48권6호
• /
• pp.767-776
• /
• 2006

젖소의 강건성 및 생산수명과 밀접한 관련성이 있는 선형심사형질들에 대한 여러가지 환경요인들의 효과를 알아보고 측정치에 영향하는 환경요인들에 대한 효과를 추정함으로써 통계적 유전분석을 위한 기초자료를 제공하고자 한국종축개량협회에서 2000년부터 2004년까지 국 Holstein 젖소 115,646두를 대상으로 측정한 15개의 선형심사 1차형질과 5개의 선형심사 2차형질에 대한 통계분석모형을 찾고 해당요인들에 대한 효과를 제시하였다. 모형설정을 위한 1차 연구로써 농가(H), 심사년도(Y), 심사월(M) 심사자(A)에 따라 분석에 고려된 대분분의 형질에서 고도의 유의적인 차이가 있었기 때문에 해당요인들을 결합한 HYMA 효과를 고려하고 산차, 비유기간, 등록구분 및 착유개시 후 심사시까지의 시간을 주 요인으로 하는 분산분석을 실시하였다. HYMA 효과에 대한 보정을 실시한 후 산차 및 비유기간은 분석에 고려된 1차 심사형질 및 2차 심사형질 전체에 있어서 고도의 유의적인 차이가 있는 것으로 분석되었고 등록구분은 유방부위의 심사점수 등 일부의 형질에서 유의적인 차이가 있는 것으로 분석된 반면에 심사시간은 대부분의 형질에서 유의적인 차이를 보이지 않았다. 유방부위의 심사점수, 유두배열 및 발굽각도 등은 산차가 증가할수록 심사점수가 감소하는 경향을 보인 반면에 기타 형질들은 산차가 증가할수록 점차 증가하는 경향을 보였다. 2～3산에서 최대의 최종심사점수를 보였는데 이는 우리나라 착유우의 생산수명이 짧고 다산우가 적은 것과 관련이 있는 것으로 추론된다. 비유기간에 따라 예각성, 뒷유방의 부착높이, 뒷유방의 너비 및 최종점수는 비유곡선과 유사한 경향치를 보이는 것으로 평가되었다. 2차 선형심사형질에 있어서는 산차가 증가하거나 비유기간이 증가할수록 지제 및 비유기관의 점수가 낮아지고 있는 경향을 보였으며 유용특질은 비유기간에 따라 비유곡선과 유사한 경향치를 보였다. 따라서 최종심사점수는 비유기간에 따른 보정을 실시함이 바람직할 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제11권5호
• /
• pp.463-469
• /
• 1998

Factor analysis was applied as a multivariate statistical technique to official genetic evaluations of type classification traits for 1,265,785 Holstein cows and 10,321 sires computed from data collected between August 1982 and June 1994 in Canada. Type traits included eighteen linear descriptive traits and eight major score card traits. Principal components of the factor analysis showed that only five factors explain the information of the genetic value of linear descriptive traits for both cows and sires. Factor 1 included traits related to mammary system, like texture, median suspensory, fore attachment, fore teat placement and rear attachment height and width. Factor 2 described stature, size, chest width and pin width. These two factors had a similar pattern for both cows and sires. In constrast, Factor 3 for cows involved only bone-quality, while in addition for sires, Factor 3 included foot angle, rear legs desirability and legs set. Factor 4 for cows related to foot angle, set of rear leg and leg desirability, while Factor 4 related to loin strenth and pin setting for sires. Finally, Factor 5 included loin strength and pin setting for cows and described only pin setting for sires. Two factors only were required to describe score card traits of cows and sires. Factor 1 related to final score, feet and legs, udder traits, mammary system and dairy character, while frame/capacity and rump were described by Factor 2. Communality estimates which determine the proportion of variance of a type trait that is shared with other type traits via the common factor variant were high, the highest ${\geq}$ 80% for final score, stature, size and chest width. Pin width and pin desirability had the lowest communality, 56% and 37%. Results indicated shifts in emphasis over the twelve-year period away from udder traits and dairy character, and towards size, scale and width traits. A new system that computes fmal score from type components has been initiated.

• Journal of Animal Science and Technology
• /
• 제44권1호
• /
• pp.1-12
• /
• 2002

젖소의 선형심사형질은 젖소의 생물학적 변이를 심사자의 직관에 의하여 변이의 정도에 따라 점수를 부여한다. 심사형질에 대한 정의에 의하여 연령과 비유기에 상관없이 변이의 정도를 수치화 하기 때문에 형질에 따라서 필연적으로 연령과 비유기의 영향을 받을 수밖에 없다. 본 연구에서는 연령과 비유기가 선형심사형질에 미치는 영향을 조사하고 그를 보정하기 위한 보정계수를 추정하였다. 키 강건성, 체심, 엉덩이 너비, 뒷다리 옆모양과 앞유방 부착이 연령에 따라 증가 또는 감소하는 경향을 보이면서 크게 영향 받는 것으로 조사되었으며, 유용성, 뒷유방 높이, 뒷유방 너비와 정중제인대는 비유기에 따라 영향을 받았다. 유방깊이는 연령과 비유기 두 가지 요인 모두로부터 영향을 받았다. 추정된 보정 계수에 의한 각각의 보정계수를 적용한 결과 연령과 비유기에 영향 받는 모든 형질에서 분만년월, 심사자 등의 변이에는 작은 영향을 미치며, 보정하고자 하는 요인의 변이를 크게 줄여 보정효과가 양호한 것으로 나타났다. 유방깊이는 연령과 비유기에 대한 보정계수를 동시에 적용한 결과 두 요인 모두에서 변이를 크게 줄였다.