Economic Value of Female Fertility and its Relationship with Profit in Spanish Dairy Cattle

González-Recio, Óscar; Pérez-Cabal, María Ángeles; Alenda, R.

doi:10.3168/jds.s0022-0302(04)73438-4

Cited by 81 publications

(63 citation statements)

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“…However, the economic importance of reproductive ability can be underestimated, if this trait alone, or together with calving interval, is included in the breeding goal, and if the costs for insemination of cows culled because of failure to conceive are not considered. Gonzá lez-Recio et al (2004) avoided this underestimation by expressing the costs for culling heifers and cows for failure to conceive as a function of the number of inseminations. The EV for the number of inseminations can be transformed to the EV for the trait 'inverse of the number of inseminations to conception', which was proposed as an alternative trait for the estimation of the breeding value for female fertility in dairy cattle by Weller and Ezra (1997).…”

Section: Definition Of Traits Expressed In Different Sexes or Animal mentioning

confidence: 99%

“…Fuerst-Waltl and Baumung (2009), for example, calculated the EV for lambing interval by reducing days to first service rather than improving conception rate. Gonzá lez-Recio et al (2004) included only the effect of prolonged days dry into the EV of calving interval. In a study by Pä rna et al (2007), calving interval reflected the ability of cows to conceive.…”

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Strategies for defining traits when calculating economic values for livestock breeding: a review

Wolfová

Wolf

2013

Animal

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The objective of the present review was (i) to survey different approaches for choosing the complex of traits for which economic values (EVs) are calculated, (ii) to call attention to the proper definition of traits and (iii) to discuss the manner and extent to which relationships among traits have been considered in the calculation of EVs. For this purpose, papers dealing with the estimation of EVs of traits in livestock were reviewed. The most important reasons for incompatibility of EVs for similar traits estimated in different countries and by different authors were found to be inconsistencies in trait definitions and in assumptions being made about relationships among traits. An important problem identified was how to choose the most appropriate criterion to characterise production or functional ability for a particular class of animals. Accordingly, the review covered the following three topics: (i) which trait(s) would best characterise the growth ability of an animal; (ii) how to define traits expressed repeatedly in subsequent reproductive cycles of breeding females and (iii) how to deal with traits that differ in average value between sexes or among animal groups. Various approaches that have been used to solve these problems were discussed. Furthermore, the manner in which diverse authors chose one or more traits from a group of alternatives for describing a specific biological potential were reviewed and commented on. The consequences of including or excluding relationships among economically important traits when estimating the EV for a specific trait were also examined. An important conclusion of the review is that, for a better comparability and interpretability of estimated EVs in the literature, it is desirable that clear and unique definitions of the traits, complete information on assumptions used in analytical models and details on interrelationships between traits are documented. Furthermore, the method and the model used for the genetic evaluation of specific traits in a certain breeding organisation are important for the exact definition of traits, for which the economic values will be calculated, and for the inclusion or exclusion of relationships among traits in the calculation of the EVs in livestock breeding. Keywords: livestock, economic values, definition of traits, relationships among traits ImplicationsA literature review was conducted on different ways of defining traits and considering relationships among them in the calculation of economic values (EVs) in livestock breeding. Diversity among trait definitions makes it difficult to compare EVs from different investigations and individual authors. It was shown that, for the EV of a trait to be correctly interpreted, it is necessary to know exactly how the trait was defined, how its relationships with other traits were accounted for and what assumptions were made in the model for the calculation of EVs. IntroductionHazel (1943) proposed the breeding objective or aggregate genotype of an animal to be defined as 'the sum of its sever...

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Section: Definition Of Traits Expressed In Different Sexes or Animal mentioning

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Strategies for defining traits when calculating economic values for livestock breeding: a review

Wolfová

Wolf

2013

Animal

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“…For example, more than 55% of US Holsteins have lactations longer than 305 days and about 25% of cows in Costa Rica are dried off after 330 days of lactation (Vargas et al, 2000). An overall increase of lactation length of 30 days for the last decade has been estimated by Gonzalez-Recio et al, (2004).…”

Section: Introductionmentioning

confidence: 99%

Analysis of lactation shapes in extended lactations

Steri

Dimauro

Canavesi³

et al. 2012

animal

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In order to describe the temporal evolution of milk yield (MY) and composition in extended lactations, 21 658 lactations of Italian Holstein cows were analyzed. Six empirical mathematical models currently used to fit 305 standard lactations (Wood, Wilmink, Legendre, Ali and Schaeffer, quadratic and cubic splines) and one function developed specifically for extended lactations (a modification of the Dijkstra model) were tested to identify a suitable function for describing patterns until 1000 days in milk (DIM).Comparison was performed on individual patterns and on average curves grouped according to parity (primiparous and multiparous) and lactation length (standard <305 days, and extended from 600 to 1000 days). For average patterns, polynomial models showed better fitting performances when compared with the three or four parameters models. However, LEG and spline regression, showed poor prediction ability at the extremes of the lactation trajectory. The Ali and Schaeffer polynomial and Dijkstra function were effective in modelling average curves for MY and protein percentage, whereas a reduced fitting ability was observed for fat percentage and somatic cell score. When individual patterns were fitted, polynomial models outperformed nonlinear functions. No detectable differences were observed between standard and extended patterns in the initial phase of lactation, with similar values of peak production and time at peak. A considerable difference in persistency was observed between 200 and 305 DIM. Such a difference resulted in an estimated difference between standard and extended cycle of about 7 and 9 kg/day for daily yield at 305 DIM and of 463 and 677 kg of cumulated milk production at 305 DIM for the first-and second-parity groups, respectively. For first and later lactation animals, peak yield estimates were nearly 31 and 38 kg, respectively, and occurred at around 65 and 40 days. The asymptotic level of production was around 9 kg for multiparous cows, whereas the estimate was negative for first parity.

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“…In addition, less fertile cows have decreased longevity (Sewalem et al, 2008), and their lifetime production can be less than that of cows with adequate fertility (González-Recio et al, 2004). Hence, a balance between production and functional traits must be pursued, and proper economic weights must be applied to every trait.…”

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Genetic relationship of functional longevity with female fertility and milk production traits in Czech Holsteins

Zavadilová¹,

Zink²

2013

CZECH J ANIM SCI

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ABSTRACT:The objectives of this study were to estimate heritabilities of and genetic correlations among longevity, milk production, and female fertility traits of Holstein cows. Fertility traits were days open, interval from parturition to first service, and days between the first and last insemination in the first and second lactation, respectively. Production traits were first lactation milk, fat, and protein yield. Functional longevity was defined as the number of days between the first calving and culling, i.e. the length of the productive life. The linear animal model included fixed effects of month-year of first calving, regression on age at first calving, regression on milk yield (only for longevity), and random effects of herd-year, animal, and residual. Heritability estimates for fertility traits ranged from 0.02 ± 0.009 to 0.06 ± 0.004. Heritability of longevity was 0.09. Heritability estimates for production traits ranged from 0.29 ± 0.009 (fat and protein yield) to 0.34 ± 0.009 (milk yield). Genetic correlations of longevity with fertility were moderate and favourable, ranging from -0.37 ± 0.068 to -0.44 ± 0.055, except the days between the first and last insemination in the second lactation. Genetic correlations of fertility with production traits were moderate to high and unfavourable, ranging from 0.48 ± 0.042 to 0.65 ± 0.034. Substantial herd-year correlations were found between fertility traits. Residual correlations were small except for those between production traits (> 0.85) and between days open and days between the first and last insemination (0.87). Month-year of first calving effects for longevity declined between 1994 and 2002, while those for production traits and for fertility increased slightly or remained stable during this period. Between 1991 and 2003, genetic trend for longevity declined and increased for production. Estimated genetic changes for fertility were unfavourable.

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Economic Value of Female Fertility and its Relationship with Profit in Spanish Dairy Cattle

Cited by 81 publications

References 17 publications

Strategies for defining traits when calculating economic values for livestock breeding: a review

Strategies for defining traits when calculating economic values for livestock breeding: a review

Analysis of lactation shapes in extended lactations

Genetic relationship of functional longevity with female fertility and milk production traits in Czech Holsteins

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