Genetic parameters for direct and maternal calving ability over parities in Piedmontese cattle.

Carnier, Paolo; Albera, A.; Zotto, R. Dal; Groen, A.F.; Bona, Mirco Dalla; Bittante, Giovanni

doi:10.2527/2000.78102532x

Cited by 67 publications

(73 citation statements)

References 22 publications

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“…Nevertheless, our inference on a strongly negative direct-maternal genetic correlation is in agreement with previous work on calving ease using threshold models [3,25,46] and linear mixed models using data from the same source [7]. Hence, it appears from our results, in agreement with other studies, that selection of sires for calving ease of their progeny as calves should result in antagonistic effects in the ability of their daughters to calve easily as dams in successive generations.…”

Section: Discussionsupporting

confidence: 82%

“…A total of 1212 herd-year-season (HYS) contemporary subclasses were created from combinations of herd, year, and two different seasons (from November to April and from May to October) as in Carnier et al [7] who also analyzed calving ease data from this same population. The sire pedigree file was further pruned by striking out identifications of sires having no daughters with calving ease records and appearing only once as either a sire or a maternal grandsire of a sire having daughters with records in the data file.…”

Section: Italian Piemontese Calving Ease Datamentioning

confidence: 99%

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Cumulative t-link threshold models for the genetic analysis of calving ease scores

Kızılkaya

Carnier

Albera³

et al. 2003

Genet. Sel. Evol.

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-In this study, a hierarchical threshold mixed model based on a cumulative t-link specification for the analysis of ordinal data or more, specifically, calving ease scores, was developed. The validation of this model and the Markov chain Monte Carlo (MCMC) algorithm was carried out on simulated data from normally and t 4 (i.e. a t-distribution with four degrees of freedom) distributed populations using the deviance information criterion (DIC) and a pseudo Bayes factor (PBF) measure to validate recently proposed model choice criteria. The simulation study indicated that although inference on the degrees of freedom parameter is possible, MCMC mixing was problematic. Nevertheless, the DIC and PBF were validated to be satisfactory measures of model fit to data. A sire and maternal grandsire cumulative t-link model was applied to a calving ease dataset from 8847 Italian Piemontese first parity dams. The cumulative t 4 -link model was shown to lead to posterior means of direct and maternal heritabilities (0.40 ± 0.06, 0.11 ± 0.04) and a direct maternal genetic correlation (−0.58 ± 0.15) that were not different from the corresponding posterior means of the heritabilities (0.42 ± 0.07, 0.14 ± 0.04) and the genetic correlation (−0.55 ± 0.14) inferred under the conventional cumulative probit link threshold model. Furthermore, the correlation (> 0.99) between posterior means of sire progeny merit from the two models suggested no meaningful rerankings. Nevertheless, the cumulative t-link model was decisively chosen as the better fitting model for this calving ease data using DIC and PBF.threshold model / t-distribution / Bayesian inference / calving ease

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Section: Discussionsupporting

confidence: 82%

Section: Italian Piemontese Calving Ease Datamentioning

confidence: 99%

Cumulative t-link threshold models for the genetic analysis of calving ease scores

Kızılkaya

Carnier

Albera³

et al. 2003

Genet. Sel. Evol.

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“…This result is also controversial and has not been found consistently across populations (Eaglen & Bijma, 2009). High genetic correlations are also observed for calving difficulty between first and later parities (Carnier et al, 2000;Eriksson et al, 2004). This means that similar genes and mechanisms may be involved in both parity levels and that some cows may be more genetically predisposed to dystocia.…”

Section: Dystociamentioning

confidence: 82%

Effects of main reproductive and health problems on the performance of dairy cows: a review

Hossein-Zadeh

2013

Span. j. agric. res.

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Reproductive efficiency is a critical component of a successful dairy operation and acts as an important component of a profitable dairy farm, whereas reproductive inefficiency is one of the most costly problems facing the dairy industry today. Reproductive problems occur frequently in lactating dairy cows and can dramatically affect reproductive efficiency in a dairy herd. Some of the most common problems include twinning, dystocia, abortion, stillbirth, retained placenta and metritis. These are diverse disorders that are similar in that they all can result in impaired reproductive function. Deciding whether to breed, treat, or cull dairy cows exhibiting one or more of these reproductive problems is a challenge for both veterinarians and dairy producers. In addition, there is considerable controversy among dairy scientists and bovine practitioners regarding the economic impact of these problems in a dairy operation and the most effective management or therapeutic intervention for treating them. Because of this controversy, dairy managers should focus on prevention and control of risk factors associated with each problem rather than on prescriptive therapeutic interventions. Dairy producers should work closely with their herd veterinarian to develop such management strategies and discuss appropriate interventions when necessary (Fricke, 2001).Low fertility reduces the profit by decreasing the average milk production and the number of calves per cow per year. Poor reproductive performance is a major cause of involuntary culling and therefore reduces the AbstractThis review focuses on the potential effects of twinning, dystocia, stillbirth, abortion, retained placenta and metritis on the productive and reproductive performances in dairy cattle. These are diverse disorders that are similar in that they all can result in impaired performance of dairy cows. Reproductive problems occur frequently in lactating dairy cows and can dramatically affect reproductive efficiency in a dairy herd. Poor reproductive performance is a major cause of involuntary culling and therefore reduces the opportunity for voluntary culling and has a negative influence on the subsequent productivity of a dairy herd. Reproductive performance is influenced by the interactive effect of environment, management, health, and genetic factors. In addition, diseases mainly affect dairy cow productivity by decreasing reproductive efficiency, shortening the expected length of productive life and by lowering milk production. Deciding whether to breed, treat, or cull dairy cows showing one or more of these problems is a challenge for both veterinarians and dairy producers. In addition, there is considerable debate among dairy scientists and bovine practitioners regarding the economic impact of these problems in a dairy operation and the most effective management or therapeutic intervention for treating them. Because of this controversy, dairy managers should focus on prevention and control of risk factors associated with each problem rather than on prescr...

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“…When linear models are applied, usually, CE scores are directly used as phenotypes (Carnier et al 2000;Gutierrez et al 2007;Cervantes et al 2010). This is possible because CE is conveniently classified on a numerical category scale.…”

Section: Resultsmentioning

confidence: 99%

“…The TM takes into account the asymmetry and extreme incidence of some categories. However, in several studies, preference was given to the use of linear models (Carnier et al 2000;Eaglen and Bijma 2009). The purpose of this research was to estimate variance components and genetic parameters for CE using TM and three linear models (LM) and to compare breeding values ranking lists achieved from the two methodologies.…”

Section: Introductionmentioning

confidence: 99%

Genetic parameters of calving ease in dairy cattle using threshold and linear models

Silvestre

Martins

Santos

et al. 2018

Italian Journal of Animal Science

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Genetic parameters of direct and maternal effects for calving ease (CE) in Portuguese dairy cattle were estimated applying a threshold model (TM) and three linear models (LM) using 320,953 CE records. In LM, CE scores were directly used as dependent variables (LM1) or were transformed into values on an underlying continuous liability scale (average and maximum values for LM2 and LM3, respectively). The estimate of heritability for direct effects was lower on linear models (0.04-0.05) than in TM (0.09). Furthermore, direct heritability was higher than maternal heritability, ranging between 0.04-0.09 and 0.01-0.02, respectively. The genetic correlation between direct and maternal effects was negative in all models, ranging between -0.75 and -0.82. We investigated the association between bulls estimated breeding values (EBV) attained by TM and three LM, for 2223 bulls. Results show that all correlations were higher than 0.95 and slightly greater correlations were observed for direct effects than for maternal effects. Particular emphasis was given to individual differences between EBV ranking lists. The average difference between rank positions of TM and the three LM ranged from 64 to 122. Therefore, the selection of breeding animals is influenced by the model's choice. Even with clear theoretical advantages in analysing categorical data, perhaps due to its more recent implementation, TM has not yet achieved the popularity of LM. The results of this work show that TM ranking list is more in accordance with LM2 than with LM1 or LM3. Therefore, with linear models, CE should be considered as average liability value instead of usual numerical score or maximum liability. ARTICLE HISTORY

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Genetic parameters for direct and maternal calving ability over parities in Piedmontese cattle.

Cited by 67 publications

References 22 publications

Cumulative t-link threshold models for the genetic analysis of calving ease scores

Cumulative t-link threshold models for the genetic analysis of calving ease scores

Effects of main reproductive and health problems on the performance of dairy cows: a review

Genetic parameters of calving ease in dairy cattle using threshold and linear models

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