Effects of Age and Stage of Lactation on Type Classification

Hansen, L.R.; Barr, G.R.; Wieckert, D.A.

doi:10.3168/jds.s0022-0302(69)86622-1

Cited by 20 publications

(19 citation statements)

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“…There is, however, substantial information about a cow's production available through type appraisal. The two type traits which have been effective in predicting producing ability have been udder depth and dairy character rating (1,2,8,14,17). The results of the regression analyses indicate the udder traits were a slightly better indicator of production than were the management or body traits.…”

Section: Resultsmentioning

confidence: 88%

“…The correlations of sharpness-17 with milk and fat yield in this study were .15 and .14. Correlations of .20 to .55 have been reported (1,8,14) using type classification ,JOURNAL OF DAIRY SCIENCE VOL. 55, No.…”

Section: Resultsmentioning

confidence: 99%

“…aPresent Address: Animal Improvement Programs Laboratory, Agricultural Research Service, USDA, Beltsville, Maryland, 20705. 4,8,11,12,14,19,21,22,26) have shown low phenotypic correlations (average, .15) between final score and milk or milk fat yield. A few of these studies calculated phenotypic correlations between production and type categories: general appearance .00 to .17; dairy character .18 to .55; body capacity .08 to .17; mammary system .03 to .28; feet and legs .01 to .09; and rump .00 to .07.…”

Section: Introductionmentioning

confidence: 99%

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Type Appraisal: III. Relationships of First Lactation Production and Type Traits with Lifetime Performance

Norman¹,

Vleck²

1972

Journal of Dairy Science

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Phenotypic and genetic correlations were estimated between 48 type appraisal traits and first lactation milk production to determine the importance of appraisal traits in a breeding program from 5,024 records from the New York type appraisal program. Most phenotypic correlations amgng the type traits were near zero. Depth of udder was the appraisal trait having the highest correlation with first lactation milk (.27) and fat (.23). Multiple correlations of all appraisal traits with first lactation milk and fat were .44 and .40.Correlations with lifetime variables were calculated from 2,068 records meeting time qualifications. Of the first lactation variables, milk yield had the highest correlation with lifetime milk (.34), and fat yield had the highest correlation with number of lactations (.21). All appraisal traits combined were as effective as production variables in predicting number of lactations.Genetic correlations suggested that bulls that sire daughters with high production tend to sire daughters with weaker udder attachments. High genetic correlations between first lactation production and lifetime performance support the utility of selection on first lactation production.

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Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Type Appraisal: III. Relationships of First Lactation Production and Type Traits with Lifetime Performance

Norman¹,

Vleck²

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

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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Conformational traits and their relation to production in Norwegian Red Cattle

Zarnecki

Fimland

Rønningen

1985

J Animal Breeding Genetics

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Summary The correlations between sire progeny group means of 23 subjectively scored conformation traits, body and udder measurements, and milk and meat indices were computed for 273 Norwegian Red bulls. Data were collected from 19439 first‐calf heifers. The principal component analysis of the correlation matrix showed that only a few traits could be considered as being redundant. Correlations between progeny group means and breeding value estimates were assumed to approximate the genetic correlations. This assumption allowed the principal components to be interpreted as additive linear indices. The first principal component of body and leg traits, the so called size vector, ranked animals from smallest to largest. The second principal component, the shape vector, contrasted large, more muscular cows with smaller, narrower‐bodied animals in which faults occured more frequently. Analysis of udder conformation gave results which were more difficult to interpret. The first principal component could not be treated as a size vector and big udders were more often related to undesirable characteristics. Multiple regression showed moderate relationships between all traits considered and both milk (R2 = 0.47) and meat indices (R2 = 0.15). Heritabilities of all traits were lower than reported in other studies on conformational traits and measurements. The majority of heritability estimates were below 0.1. Considering the low heritabilities shown by conformational and measurement traits and the poor relationship with production, only those that contribute to longevity should be retained. This, however, would require further studies on survival data. Résumé Caractéristiques de forme et typiques et leurs relation à la performance en pie‐rouge norvégienne Les corrélations entre les valeurs moyennes de la progéniture des pères de 23 caractères estimés subjectivement, mesures des corps et des pis, ainsi que des indices de lait et de viande ont été calculées pour 273 taureaux pie‐rouge norvégienne. Les dates provenaient de 19.439 génisses primipares. La composante principale d'une analyse de la matrice de corrélation montrait que seulement peu des caractères peuvent être considérés comme superflu. Les corrélations entre valeurs moyennes des groupes de progéniture et les estimations de la valeur héréditaire ont été considérées comme approximation aux corrélations génétiques. Cette approximation permettait l'interpretation des composantes principales comme indices additifs linéaires. La première composante principale des caractéristiques du corps et des jambes, appelée vecteur des grandeurs, classait les animaux du plus petit au plus grand. La seconde composante principale, vecteur des formes, confrontait les grandes vaches musculaires aux vaches plus petites et minces possédant plut tôt des fautes. L'analyse de la forme des pis donnait des résultats plus difficile à interpréter. La première composante principale ne pouvait pas être traitée comme vecteur des formes et les gros pis étaient souvent reliés à des caractéristiques indési...

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Effects of Age and Stage of Lactation on Type Classification

Cited by 20 publications

References 4 publications

Type Appraisal: III. Relationships of First Lactation Production and Type Traits with Lifetime Performance

Type Appraisal: III. Relationships of First Lactation Production and Type Traits with Lifetime Performance

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

Conformational traits and their relation to production in Norwegian Red Cattle

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