Genetic relationship of yield and fertility in dairy cattle

Hansen, Leslie B

doi:10.31274/rtd-180813-4679

Cited by 4 publications

(7 citation statements)

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“…Repeatability of fertility in first parity was higher than for second and third parities. Repeatability in second parity tended to be smaller than third parity, Hansen (1981) pointed out that the major cause of infertility is probably poor repro ductive management. Improved fertility may be favorably related to im proved milk production because virgin heifers that milk most in first lactations conceive easier, but stress of increased milk production may depress the genetic potential for improved fertility.…”

Section: Days Dry and Days Openmentioning

confidence: 98%

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Evaluating crossbred dairy cattle for reproduction and production traits and their genetic potential in Thailand

Kassumma

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Optimum Proportion of Bos Taurus 24 Age at First Calving 27 Days Dry and Days Open 29 Calving Interval 30 Lactation Length 33 Milk Production 34 Conclusions 38 DESCRIPTION OF DATA 42 Thai-Danish Dairy Farm, Foundation Cattle and Breeding Policy 42 Feeding and Management 45 Data Preparation 46 Additive genetic effects 55 Heterozygotic and homozygotic coefficients Obtaining additive, heterozygotic, homozygotic and general heterozygotic coefficients Age at calving Season effects 67 Year effects Days open Milk yield iii METHODS OF ANALYSIS 71 RESULTS AND DISCUSSION 77 Means and Standard Errors of Reproduction Traits 84 Means and Standard Errors of Production Traits 86 Model 1. 93 Environmental Effects 93 Breed Group Effects Reproduction Traits 105 Age at calving 105 Days open 106 Lactation length 114 Days dry 115 Calving interval Production Traits Milk yield Conclusions 132 Model 2 133 Model 3 134 Breed additive and nonadditive genetic effects 134 Age at calving 141 Days open Lactation length Days dry Calving interval Milk yield Conclusions Model 4

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Section: Days Dry and Days Openmentioning

confidence: 98%

“…Louca and Legates (1968) (Berger et al, 1981). Hansen (1981) studied fertility in the Holstein breed. In general, heritability of several measures of fertility in heifers tended to be slightly higher than for cows, Heritability of fertility ranged from 0 to ,03 for lactating cows.…”

Section: Days Dry and Days Openmentioning

confidence: 99%

Evaluating crossbred dairy cattle for reproduction and production traits and their genetic potential in Thailand

Kassumma

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“…The fourth data set was from the dissertation research of Les Hansen (Hansen (1981)), These data had been analyzed previously with Method III and also with single-trait REML (without relationships)…”

Section: Simulated Datamentioning

confidence: 99%

“…A subset, 15,684 cows, also had information on their reproductive traits as heifers. Four hundred twenty-eight sires were included in the analysis, 353 of these because they had at least 10 daughters in the data and the remaining 75 because they were necessary for construction of A Although Hansen (1981) analyzed 21 traits, several of these were linearly confounded or nearly so, and this would give singular matrices and canputing…”

Section: Simulated Datamentioning

confidence: 99%

Computational strategies for estimation of variance components

VanRaden

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Output from ABSORBM for Example Data Set 110 Output fran REMLM for Example Data Set 111 REVIEW OF LITERATURE Estimation of variance components has been and will continue to be one of the major tasks concerning animal breeders. Heritabilities, repeatabilities, and genetic correlations are functions of variance components and are required in order to intelligently design breeding programs, to set up selection index equations, or to rank animals by more sophisticated strategies such as BLUP. One would think that accurate estimation of variance components would be no problem in animal breeding situations because very large data sets are often available. Unfortunately, the data are almost always unbalanced, often undesigned, and usually contain selection. This can make it impossible to obtain estimates of variance components with desirable properties no matter how many data are available unless the more sophisticated estimation methods are used. Methods of Estimation and Their Properties Until 1353, the only available methods of variance component estimation applied only to balanced data or to unbalanced data in very simple designs such as the one-way classification (Freeman (1979)), These methods were based on the analysis of variance (ANOVA) and relied on partitioning mean squares into an amount attributable to error variance and an amount due to variance of the effect in question.

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“…Parameter estimates in column one of Table 21 The data were also analyzed as single traits (Table 22) using a univariate REML procedure in SAS (1985). (Harville, 1977;Hill and Thompson, 1978;Hill 1980 and1981;and Henderson, 1984a) all suggest including restraints on parameter estimates such that eigenvalues will be positive and estimated variances will be within the allowable parameter space. No one has yet compared estimates from a full multiple trait analysis with those obtained by a canonical transformation.…”

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confidence: 99%

Multiple trait variance-covariance component estimation procedures with missing information for some traits

Valente

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Valente, Jose, "Multiple trait variance-covariance component estimation procedures with missing information for some traits " (1988 INFORMATION TO USERSThe most advanced technology has been used to photo graph and reproduce this manuscript from the microfilm master. UMI films the original text directly from the copy submitted. Thus, some dissertation copies are in typewriter face, while others may be from a computer printer.In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyrighted material had to be removed, a note will indicate the deletion.Oversize materials (e.g., maps, drawings, charts) are re produced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each oversize page is available as one exposure on a standard 35 mm slide or as a 17" x 23" black and white photographic print for an additional charge.

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Genetic relationship of yield and fertility in dairy cattle

Cited by 4 publications

References 60 publications

Evaluating crossbred dairy cattle for reproduction and production traits and their genetic potential in Thailand

Evaluating crossbred dairy cattle for reproduction and production traits and their genetic potential in Thailand

Computational strategies for estimation of variance components

Multiple trait variance-covariance component estimation procedures with missing information for some traits

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