Changes in Type Ratings of Holstein Cows due to Age, Season, Stage of Lactation, Classifier, and Year

Wilcox, C.J.; Mather, R.E.; Pfau, K.O.; Gabriel, Ray; Bartlett, John

doi:10.3168/jds.s0022-0302(59)90818-5

Cited by 13 publications

(12 citation statements)

References 5 publications

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“…Herd or year effects on type ratings have generally been smaller than on milk production (3,13,16,23,27,30). Van Vleck (27) and Carter, Rennie, and Burnside (3) suggested herdmates need not be considered when reporting type ratings for sires' daughters.…”

Section: Introductionmentioning

confidence: 99%

Type Appraisal: II. Variation in Type Traits Due to Sires, Herds, and Years

Norman

Vleck

1972

Journal of Dairy Science

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Variance components were estimated from type appraisal data to determine the importance of year, herd, sire, and herd x sire effects uport 49 body, udder, and management traits. Estimates were based on over 16,000 appraisals on daughters of Holstein artil~cial insemination sires. The variation explained by these effects never exceeded 34g of the total variance. Year effects were almost nonexistent (--2 to 3g). Herd effects were small for all traits except feeding speed, body weight, intensity and persistency of edema, and ketosis, and never exceeded 25g.Most appraisal traits had low heritabilities. The estimate for milking speed was .23 while estimates for other management traits were less than .08. The estimates for body weight and upstandingness were .40 and .39. Other body traits having estimates from .16 to .21 were sharpness, height of thurls, depth of body, levelness of rump, tightness of shoulders, and height of tail setting. The heritability estimates for udder traits were low. Estimates for only three of 21 udder traits exceeded .14. These were strength of rear attachment, rear teat spacing, and depth of udder.

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Section: Introductionmentioning

confidence: 99%

Type Appraisal: II. Variation in Type Traits Due to Sires, Herds, and Years

Norman

Vleck

1972

Journal of Dairy Science

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“…Muitos autores concluem ser o efeito da idade à classificação um dos mais importantes na avaliação das características lineares (Wilcox et al, 1959;Hansen et al, 1969;White, 1974;Norman et al, 1983;Cue et al, 1996). Para White (1974), de todos os fatores de ambiente que podem influenciar os resultados de escores lineares de vacas leiteiras, a idade do animal à classificação é o mais importante.…”

Section: Methodsunclassified

“…5). Ausência do efeito da idade sobre as características de pernas/pés também foi verificada por Wilcox et al (1959), Hansen et al (1969) e Rennie et al (1974). Ainda, os efeitos de idade sobre as características de garupa variaram consideravelmente, sendo importantes apenas para largura (P<0,01; Tab.…”

Section: Methodsunclassified

“…Estudos mostram que há influência dos fatores de meio como rebanho, ano e estação de classificação, estádio da lactação, idade ou ordem do parto, classificador, dentre outros, sobre as características lineares de tipo (Wilcox et al, 1959;Norman e Vanvleck, 1972a;Rennie et al, 1974;Thompson et al, 1983;Lawstuen et al, 1987). Lucas et al (1984) e Funk et al (1991) estudaram os efeitos de meio sobre as características de conformação em vacas da raça Holandesa, encontrando efeitos significativos da idade da vaca, do estádio da lactação e do classificador sobre algumas características de tipo.…”

Section: Introductionunclassified

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Estudo dos efeitos de ambiente sobre as características lineares de tipo em rebanhos bovinos da raça Holandesa

Esteves¹,

Bergmann²,

Durães

et al. 2004

Arq. Bras. Med. Vet. Zootec.

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Estudo dos efeitos de ambiente sobre as características lineares de tipo em rebanhos bovinos da raça Holandesa RESUMOEfeitos de estádio da lactação, idade à classificação e grupo contemporâneo de rebanho, ano e estação de classificação foram considerados nas análises de 21 características lineares de tipo e pontuação final de 2.122 animais da raça Holandesa, filhos de 178 reprodutores e nascidos em 83 rebanhos. Utilizou-se o método dos quadrados mínimos nas análises de variância das características. O efeito de estádio da lactação teve influência sobre as características do sistema mamário, evidenciando que houve alterações morfológicas durante o período de lactação para todas as características de úbere, exceto inserção do úbere anterior, textura do úbere e comprimento dos tetos. Dentre as características de conformação/capacidade corporal, profundidade corporal foi a mais influenciada pelo estádio da lactação, seguida do tamanho corporal, largura torácica e força lombar. Para todas as características de conformação/capacidade corporal o efeito da idade à classificação revelou-se altamente significativo. Dentre as características lineares da categoria pernas/pés, a variável idade à classificação foi importante (P<0,05) apenas para vista lateral das pernas. O efeito de idade sobre as características de garupa variou consideravelmente, sendo importante apenas para largura (P<0,01). Pontuação final e angulosidade também foram influenciadas (P<0,01) pelo efeito da idade. A verificação de significância estatística indicou a existência de componentes de meio e evidenciou a importância do estudo desses componentes.Palavras-chave: bovino, característica linear de tipo, efeito de ambiente, Holandês ABSTRACTStage of lactation, classification age and herd-year-season contemporary group effects were considered in the analyses of 21 linear type traits, in addition to final score using 2,122 Brazilian Holstein cows, from 83 herds and daughters of 178 sires. Least square methodology was applied in the analyses of variance. With the exception of fore udder attachment, udder texture and fore teat length, the effect of stage of lactation was important ((P<.05) for all other mammary system traits, indicating that there were morphological changes during lactation. All traits related to conformation/body capacity were influenced by classification age. Among these traits, body deep was the one affected by stage of lactation, followed by body size, chest width and loin strength. Among traits related to feet and legs, the effect of age of the animal on side view of rear legs was important (P<.05). The effect of age on traits related to rump was variable, being important (P<.05) only for rump width. Final score and angularity were also influenced by age (P<.05). This study revealed the importance of environment type trait effects on linear type trait evaluations.

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“…Benson, Tyler, and Hyatt (1) later reported differences in rating due to age, season, and year of classification were nonsignificant but found substantial differences in type score due to stage-of-lactation. Wilcox et al (7,8) reported both age and stage-of-lactation influences in Holstein type classification data. These workers reported that type traits with the exception of dairy character were classified higher in early and late lactation than in mid-lactation.…”

Section: Introductionmentioning

confidence: 99%

Type Appraisal: I. Effects of Age and Stage-of-Lactation on Type Ratings

Norman

Vleck

1972

Journal of Dairy Science

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Dairy cattle type appraisal data were examined to determine whether body and udder conformation and management ratings were affected by age and period of lactation at appraisal. Data were collected from 1961 to 1968 from 188 herds having over 23,000 Holstein type appraisals. The body and udder traits were scored by scheduled appraisers, and the management traits were coded by each dairyman. Some of the 35 original traits were composed of more than one descriptive characteristic and, as a result, 49 renamed traits were derived from these.A model was selected that considered years and herds as well as cow effects to reduce bias in the estimates of age x stage-of-lactation differences that would result frcm culling cows on type score. Age differences were large for about onethird of the traits, especially for mastitis, body weight, and depth of udder. In general, differences from stage-of-lactation were not as large as from age; nevertheless, trends were evident for several traits. Interactions between age and stage-of-lactation were relatively small.

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Changes in Type Ratings of Holstein Cows due to Age, Season, Stage of Lactation, Classifier, and Year

Cited by 13 publications

References 5 publications

Type Appraisal: II. Variation in Type Traits Due to Sires, Herds, and Years

Type Appraisal: II. Variation in Type Traits Due to Sires, Herds, and Years

Estudo dos efeitos de ambiente sobre as características lineares de tipo em rebanhos bovinos da raça Holandesa

Type Appraisal: I. Effects of Age and Stage-of-Lactation on Type Ratings

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