Variation of Milk, Fat, Protein, and Somatic Cells for Dairy Cattle

Schutz, M.M.; Hansen, Leslie B; Steuernagel, G. R.; Kuck, A.L.

doi:10.3168/jds.s0022-0302(90)78696-1

Cited by 119 publications

(91 citation statements)

References 24 publications

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“…Lower peak for milk yield of primiparous cows and lower persistency for multiparous cows have been also reported and discussed in numerous previous studies (Danell, 1982;Keown et al, 1986;Stanton et al, 1992;Bormann et al, 2002). The observed peak in milk yield appeared earlier when compared to other studies (Schutz et al, 1990;Stanton et al, 1992;Bormann et al, 2002). Typically, peak for milk yield of Holsteins is observed at approximately 45 DIM what could be the consequence of higher level of production when compared to average yield of cows analysed in this study.…”

Section: Discussionmentioning

confidence: 48%

Age-season lactation curves for production traits of cows calving in Wielkopolska region of Poland

Strabel¹

2004

J. Anim. Feed Sci.

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The objective of this study was to estimate lactation curves for cows of different age at calving in winter and summer seasons. Data consisted of 1 289 522 test-day records of cows calved in Wielkopolska region in 1992-1996. Milk, fat and protein yields in fi rst three parities were studied. Test-day model with 50 classes of days-in-milk by parity was used. Lactation curves were derived from solutions for this effect. They were fl atter for fi rst versus later lactations. Peak yield for milk production occurred in the second part of the fi rst month of production. Shape of lactation curves for different age and season classes did not vary substantially. Cows calving in winter season had higher production. Similarly, older cows had higher yields for all traits and lactations, however the evidence of age at calving by season of calving interaction was found.

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Section: Discussionmentioning

confidence: 48%

Age-season lactation curves for production traits of cows calving in Wielkopolska region of Poland

Strabel¹

2004

J. Anim. Feed Sci.

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“…Schutz et al (1990) also showed that after 250 days of lactation, daily milk yield of HF cows in the first parity cows was higher than that in the second parity cows. The fact that log SCC levels increased with parity and with days in milk, means milking a large number of mature cows in a herd after 300 days could have a negative economic consequence and result in a loss of premium milk price.…”

Section: Discussionmentioning

confidence: 88%

Genetic and phenotypic parameters of lactations longer than 305 days (extended lactations)

Haile‐Mariam¹,

Goddard

2008

Animal

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Test-day milk yield and somatic cell count data over extended lactation (lactation to 540-600 days) were analysed considering part lactations as different traits and fitting random regression (RR) models. Data on Australian Jersey and Holstein Friesian (HF) were used to demonstrate the shape of the lactation curve and data on HF were used for genetic study. Test-day data from about 100 000 cows that calved between 1998 and 2005 were used for this study. In all analyses, a sire model was used.When part lactations were considered as different traits, protein yield early in the lactation (e.g. first 2 months) had a genetic correlation of about 0.8 with protein yield produced after 300 days of lactation. Genetic correlations between lactation stages that are adjacent to each other were high (0.9 or more) within parity. Across parities, genetic correlations were high for both protein and milk yield if they are within the same stage of lactation. Phenotypic correlations were lower than genetic correlations. Heritability of milk-yield traits estimated from the RR model varied from 0.15 at the beginning of the lactation to as high as 0.37 by the 4th month of lactation. All genetic correlations between different days in milk were positive, with the highest correlations between adjacent days in milk and decreasing correlations with increasing time-span. The pattern of genetic correlations between milk yield in the second 300 days (301 to 600 days of lactation) do not markedly differ from the pattern in the first 300 days of lactation. The lowest estimated genetic correlation was 0.15 between milk yield on days 45 and 525 of lactation. The result from this study shows that progeny of bulls with high estimated breeding values for yield traits and those that produce at a relatively high level in the first few months are the most likely candidates for use in herds favouring extended lactations.

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“…A curva de lactação, observada neste estudo, não segue a mesma tendência observada por Schutz et al (1990), Stanton et al (1992), Machado (1997) e Ferreira (1999) para a raça Holandês, onde o pico de produção ocorreu entre o segundo e terceiro controles.…”

Section: Resultsunclassified

Estimativa de parâmetros genéticos, fenotípicos e ambientes para as produções de leite no dia do controle e em 305 dias de lactação de vacas da raça Gir

et al. 2002

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RESUMO -Dados de 32.779 controles mensais, de 3.605 lactações em 305 dias (PL305), de 2.082 vacas Gir, filhas de 281 touros, com partos ocorridos de 1987 a 1999, em 11 rebanhos, foram usados com o objetivo de verificar a viabilidade de utilização da produção de leite no dia do controle (PLDC1 a PLDC10) em avaliações genéticas da raça Gir. Foram realizadas análises bivariadas entre as PLDC1 a PLDC10 e PL305, usando para estimar os componentes de (co)variâncias o método de máxima verossimilhança restrita, sob modelo animal, incluindo as três primeiras lactações como medidas repetidas de uma mesma vaca, diferenciadas conforme o grupo contemporâneo de rebanho-ano-estação, de acordo com a idade da vaca ao parto e o intervalo parto-primeiro controle na PLDC1. As médias observadas e os respectivos desvios-padrão (kg) para PLDC1 a PLDC10 e PL305 foram: 11, 97±4,64; 11,93±4,68; 10,98±4,40; 10,18±4,12; 9,66±3,88; 9,20±3,69; 8,63±3,51; 8,08±3,33; 7,59±3,27; 7,22±3,15 e 2.746,17±1.299,90. A duração de lactação foi de 273,72±48,95 dias. As estimativas de herdabilidade variaram nas PLDC de 0,24 a 0,14, sendo maior no primeiro controle e decrescendo até o décimo. A herdabilidade da PL305 foi de 0,19. As estimativas de correlações genéticas entre as PLDC e PL305 variaram de 0,85 a 1,00. As correlações genéticas entre PLDC1 a PLDC9 com PLDC6 a PLDC10 foram acima de 0,80, à exceção entre PLDC9 com PLDC1 e PLDC10 com PLDC1, PLDC2, PLDC3 e PLDC6, que foram inferiores. As correlações fenotípicas tiveram valores intermediários entre as correlações genéticas e as residuais (menores). Considerando a eficiência relativa de seleção, esta mostrou que se baseada nas PLDC2 a PLDC4 ocorrerá a mesma ou melhor resposta que se praticada na PL305.Palavras-chave: bovino de leite, controle leiteiro, eficiência de seleção, melhoramento genético Genetic, Phenotypic and Environmental Parameters for Milk Production at the Control Day and 305 Days of Lactation of Gir Breed CowsABSTRACT -Data from 32,779 monthly milk production, from 3,605 lactations until 305 days (PL305), from 2,082 Gir cows, sired by 281 bulls, calving from 1987 to 1999, in 11 herds, were used to verify the viability of using daily milk production control (PLDC) to perform genetic evaluations within Gir breed. Bivariate analysis on PLDC1 to PLDC10 and PL305 were performed utilizing the restricted maximum likelihood method within an animal model, which included the three first lactations as replicate measures of the same dams unit. Animals were grouped according to the criterion of contemporaneous group of herd-year-season, and according to calvingage and to the interval calving-first control in PLDC1. The observed averages (kg) and the respective standard deviations for PLDC1 at PLDC10 and PL305 were: 11.97±4.64; 11.93±4.68; 10.98±4.40; 10.18±4.12; 9.66±3.88; 9.20±3.69; 8.63±3,51; 8.08±3.33; 7.59±3.27; 7.22±3.15 and 2746.17±1299.90. The average lactation length was 273.72±48.95 days. Heritability estimates for PLDC based on bivariate analysis ranged from 0.24 to 0.14, decreasing fr...

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Variation of Milk, Fat, Protein, and Somatic Cells for Dairy Cattle

Cited by 119 publications

References 24 publications

Age-season lactation curves for production traits of cows calving in Wielkopolska region of Poland

Age-season lactation curves for production traits of cows calving in Wielkopolska region of Poland

Genetic and phenotypic parameters of lactations longer than 305 days (extended lactations)

Estimativa de parâmetros genéticos, fenotípicos e ambientes para as produções de leite no dia do controle e em 305 dias de lactação de vacas da raça Gir

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