Parâmetros genéticos para produção de leite no dia do controle e para produção de leite até 305 dias nas primeiras lactações de vacas da raça Gir

Herrera, Luis Gabriel González; Faro, Lenira El; Albuquerque, Lúcia Galvão de; Tonhati, Humberto; Machado, Carlos Henrique

doi:10.1590/s1516-35982008001000009

Cited by 12 publications

(18 citation statements)

References 15 publications

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“…The correlations were close to unity between adjacent classes, decreasing to values of about 0.55 between the first and tenth class. This pattern agrees with those reported by Ledic et al (2002) and Herrera et al (2008). The reduction in the number of parameters estimated was significant for model PC2 (74 parameters) when compared to model M10 (110 parameters).…”

Section: Resultssupporting

confidence: 91%

“…Ledic et al (2002), using TDMY records from the first three lactations of Gyr cattle in two-trait analyses, found heritabilities ranging from 0.14 to 0.24. Also using two-trait analyses, Herrera et al (2008) The genetic correlations between traits (TDMY classes) obtained with the two models were also similar, although slightly higher values were estimated with model PC2 (Figure 2). This finding can be explained by the fact that correlations between traits are forced to have an absolute value of unity when one or few principal components are fitted (Meyer, 2007a).…”

Section: Resultsmentioning

confidence: 57%

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Comparison of factor-analytic and reduced rank models for test-day milk yield in Gyr dairy cattle (Bos indicus)

Pereira

Ayres²,

Faro³

et al. 2013

Genet. Mol. Res.

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ABSTRACT. We analyzed 46,161 monthly test-day records of milk production from 7453 first lactations of crossbred dairy Gyr (Bos indicus) x Holstein cows. The following seven models were compared: standard multivariate model (M10), three reduced rank models fitting the first 2, 3, or 4 genetic principal components, and three models considering a 2-, 3-, or 4-factor structure for the genetic covariance matrix. Full rank residual covariance matrices were considered for all models. The model fitting the first two principal components (PC2) was the best according to the model selection criteria. Similar phenotypic, genetic, and residual variances were obtained with models M10 and PC2. The heritability estimates ranged from 0.14 to 0.21 and from 0.13 to 0.21 for models M10 and PC2, respectively. The genetic correlations obtained with model PC2 were slightly higher than those estimated with model M10. PC2 markedly reduced the number of parameters estimated and the time spent to reach convergence. We concluded that two principal Multivariate analyses for test-day milk yield components are sufficient to model the structure of genetic covariances between test-day milk yields.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 57%

Comparison of factor-analytic and reduced rank models for test-day milk yield in Gyr dairy cattle (Bos indicus)

Pereira

Ayres²,

Faro³

et al. 2013

Genet. Mol. Res.

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“…The mean observed for the Gir herd (296.4 days) was greater than the means reported by Herrera et al (2008) and Prata et al (2014) for the same breed. The estimated mean DL in Guzera was 244.2 days for cows that calved males and 237.1 days for cows that calved females, and the mean observed for the herd (241.4 days) was lower than that found by Verneque et al (2008) and by Rangel et al (2009).…”

Section: Resultscontrasting

confidence: 64%

“…In Gir, the mean P305 was 3,386.8 kg (Table 1), which is higher than the 2,846.95 kg reported by Prata et al (2014) for this breed. In Guzera, the observed mean was 2,046.5 kg, which is lower than the mean production of 2,170.24 kg per lactation reported by Herrera et al (2008). The variation coefficient (VC) for P305 in Holsteins was 18.3%, which is lower than the 29.9% reported by Ferreira et al (2003).…”

Section: Resultsmentioning

confidence: 54%

Fetal sex influence in the productive performance of dairy cows

Freitas

Gama

Santos

et al. 2016

SCA

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Investigating factors that could affect milk production of cows is an important way to improve the efficiency of production systems. The purpose of this study was to verify and quantify the influence of calf sex on milk production and lactation length in herds of Holstein, Gir, and Guzera cows. Data from 10,780 lactations of 4,807 Holstein cows that calved between 2001 and 2013; 18,898 lactations of 13,172 Gir cows that calved between 1985 and 2013; and 5,277 lactations of 3,972 Guzera cows that calved between 1987 and 2013 were used. Both the accumulated 305-day milk yield (P305) and the length of the lactation period up to 305 days (DL305) were evaluated. Analysis of variance was performed by the least squares method using the GLM procedure in the SAS statistical program. The P305 was not influenced by the sex of the calf in the Holstein breed. However in the zebu breeds (Gir and Guzera), both P305 and DL305 were significantly affected (P < 0.01) by the sex of the calf, with higher production and average length of lactation in cows that calved males. In addition, a significant difference was also nested within sex of calf and age at first calving (P < 0.05) in the Gir breed. The results indicate that for the zebu breeds, calf sex influences production characteristics. Key words: Milk production. Lactation. Lactation length. ResumoA investigação de fatores que interferem na produção de vacas leiteiras é de grande importância para eficiência dos sistemas de produção. O objetivo do trabalho foi verificar e quantificar a influência do sexo do bezerro sobre produção de leite e sobre a duração da lactação em rebanhos das raças Holandesa, Gir Leiteiro e Guzerá. ocorridas entre 1987 e 2013, de 3.972 vacas Guzerá. As características estudadas foram produção de leite acumulada em 305 dias e duração da lactação (até 305 dias). A análise de variância foi realizada pelo método de quadrados mínimos, através do procedimento GLM do programa estatístico SAS. A produção de leite acumulada aos 305 dias (P305) na raça Holandesa não foi influenciada pelo sexo do bezerro. Entretanto, para os animais de origem zebuína (Gir leiteiro e Guzerá), ambas as características foram significativamente influenciadas (P<0,01) pelo sexo do bezerro, sendo observadas maiores produções de leite e duração de lactação para vacas que pariram machos. Também foi observada diferença significativa do sexo do bezerro aninhado dentro de idade da vaca ao parto (P<0,05) para a raça Gir leiteiro. Estes resultados indicam que para as raças zebuínas, o sexo do bezerro influenciou as características de produção. Palavras-chave: Produção de leite. Lactação. Duração da lactação.

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“…Dairy breeding programs have used the highest 305-day cumulative milk production for many years as the main, if not the only parameter for genetic evaluation of herds (HERRERA et al, 2008). However, the emphasis on selection for milk production has led to a decline in indicators of fertility, longevity and hygiene of dairy herds, due to unfavorable genetic correlation between these two groups of characteristics (RODRIGUEZ-MARTINEZ et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Phenotypic evaluation of trait types in Guzerá cows of different calving orders

Júnior

Rangel

Lima

et al. 2017

SCA

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The objective of this study was to evaluate the effect of parity on linear trait types in Guzerá cows using multivariate techniques. Data were collected from 68 purebred Guzera females, young (1 st and 2 nd calving order) and adults (3 rd to 7 th calving order). Measurements were collected using a tape measure, a hypometer, a 40 cm graduated ruler and a 180° protractor. PRCOMP procedure of the R program was used for analyzing the main components. The variables related to rump (height, angularity, ileum and ischium length and width), body (length), udder (height of posterior ligament) and milk production were more important to explain the phenotypic variation in Guzerá cattle. Young Guzerá cows had lower body length, narrower rumps, better udder ligaments and lower milk yield than adult cows. Key words: Dairy cattle. Multivariate. Zebu cattle. ResumoObjetivou-se avaliar a efeito da ordem de parto, por meio de técnicas multivariadas, sobre as características lineares de tipo de vacas da raça Guzerá. Foram utilizados dados de 68 fêmeas da raça Guzerá, puras de origem, jovens (1ª e 2ª ordem de parto) e adultas (3ª a 7ª ordem de parto). As medidas foram coletadas com auxílio de fita métrica, hipômetro, régua graduada de 40 cm e transferidor de ângulos 180°. Para as análises de componentes principais utilizou-se o procedimento PRCOMP do programa R. As variáveis relacionadas à garupa (altura, angulosidade, comprimento e largura de íleo e ísquios), corpo (comprimento), úbere (altura do ligamento posterior) e produção de leite apresentaram maior importância para explicar a variação fenotípica de bovinos Guzerá. Vacas jovens da raça Guzerá apresentaram menor comprimento corporal, garupas mais estreitas, melhores ligamentos de úbere e menor produção de leite que as vacas adultas. Palavras-chave: Bovinocultura leiteira. Multivariada. Zebuínos.

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Parâmetros genéticos para produção de leite no dia do controle e para produção de leite até 305 dias nas primeiras lactações de vacas da raça Gir

Cited by 12 publications

References 15 publications

Comparison of factor-analytic and reduced rank models for test-day milk yield in Gyr dairy cattle (Bos indicus)

Comparison of factor-analytic and reduced rank models for test-day milk yield in Gyr dairy cattle (Bos indicus)

Fetal sex influence in the productive performance of dairy cows

Phenotypic evaluation of trait types in Guzerá cows of different calving orders

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