Articles | Volume 59, issue 3
https://doi.org/10.5194/aab-59-387-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/aab-59-387-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Original study
| 
13 Sep 2016
Original study |
| 13 Sep 2016
Genetic analysis of productive life length in Holstein dairy cows using Weibull proportional risk model
Hamed Amirpour Najafabadi
CORRESPONDING AUTHOR
Department of Animal Science, College of Agriculture, Isfahan
University of Technology, 84156-83111, Isfahan, Iran
Saeid Ansari Mahyari
Department of Animal Science, College of Agriculture, Isfahan
University of Technology, 84156-83111, Isfahan, Iran
Mohammad Ali Edriss
Department of Animal Science, College of Agriculture, Isfahan
University of Technology, 84156-83111, Isfahan, Iran
Eva Strapakova
Department of Genetics and Breeding Biology, Faculty of Agrobiology
and Food Resources, Slovak University of Agriculture in Nitra, Tr. A. Hlinku
2, 94976 Nitra, Slovakia
Related authors
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Eva Strapáková, Juraj Candrák, and Peter Strapák
Arch. Anim. Breed., 59, 329–335, https://doi.org/10.5194/aab-59-329-2016, https://doi.org/10.5194/aab-59-329-2016, 2016
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The advantages of increasing lactation persistency in dairy cattle are indisputable on the practical herd level. More persistent lactation brings a longer high-production period. In this study estimate the breeding values of lactation persistency, test day of milk yield, somatic cell score, reproductive traits (calving interval, days open), and longevity in Slovak Holstein dairy cattle were estimated and the relationship between persistency of lactation and other selected trait was analyzed.
Parisa Nadri, Saeid Ansari-Mahyari, and Azadeh Zahmatkesh
Arch. Anim. Breed., 59, 167–172, https://doi.org/10.5194/aab-59-167-2016, https://doi.org/10.5194/aab-59-167-2016, 2016
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In this research, the effect of purmorphamine on mRNA expression of the SHH signaling downstream molecules Ptch1, Gli1, Smo, Hdac1, Hdac2 and Hdac3 in ovine two-cell embryos was studied. Regarding the presence of SHH signaling molecules in two-cell embryos and their response to purmorphamine, it can be suggested that SHH signaling is probably active before embryonic genome activation in ovine embryos.
Related subject area
Subject: Quantitative genetics and estimation of breeding value | Animal: Cattle
Expression pattern of ZNF33B in bovine ovaries and the effect of its polymorphism on superovulation traits
The effect of single-nucleotide polymorphisms within heat shock protein beta 1 on beef quantity in Korean native steers
Determination of genetic variation within the DYRK2 gene and its associations with milk traits in cattle
Identification of novel nucleotide sequence variations in an extended region of the bovine leptin gene (LEP) across a variety of cattle breeds from New Zealand and Nigeria
Analysis of lactating cows on commercial Austrian dairy farms: the influence of genotype and body weight on efficiency parameters
Linking first lactation survival to milk yield and components and lactation persistency in Tunisian Holstein cows
Determination of a possible relationship between a single nucleotide polymorphism (SNP) in the promoter region of the SIRT1 gene and production and reproduction traits in the Agerolese cattle breed
(Co)variance components and genetics parameter estimation for linear traits in Holstein cattle in Indonesia: traits related to foot/leg and udder
Body weight prediction using body size measurements in Fleckvieh, Holstein, and Brown Swiss dairy cows in lactation and dry periods
Genetic parameters for longitudinal behavior and health indicator traits generated in automatic milking systems
Q method to map the diversity of stakeholder viewpoints along agricultural innovation systems: a case study on cattle genetic improvement in Niger
Invited review: Genetic and genomic mouse models for livestock research
Invited review: Reproductive and genomic technologies to optimize breeding strategies for genetic progress in dairy cattle
Individual and combined effects of CAPN1, CAST, LEP and GHR gene polymorphisms on carcass characteristics and meat quality in Holstein bulls
Effects of polymorphisms at LEP, CAST, CAPN1, GHR, FABP4 and DGAT1 genes on fattening performance and carcass traits in Simmental bulls
Genetic relationship of lactation persistency with milk yield, somatic cell score, reproductive traits, and longevity in Slovak Holstein cattle
AGPAT6 gene EX1_303T > C and EX12_299G > A mutations and associations with economic traits of Chinese Simmental-cross cattle
Estimation of variance components of milk, fat, and protein yields of Tunisian Holstein dairy cattle using Bayesian and REML methods
Genetic parameters of reproductive traits in Tunisian Holsteins
Comparison of breeding values among cows with exceptional longevity and their contemporary herdmates in German Holsteins
Changhong Li, Peijun Xia, Yijuan Ma, Xinyue Zhang, and Yijia Liu
Arch. Anim. Breed., 65, 69–77, https://doi.org/10.5194/aab-65-69-2022, https://doi.org/10.5194/aab-65-69-2022, 2022
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In this study, we first studied the expression of ZNF33B in bovine ovaries and early embryos, and we determined the expression position and quantity of ZNF33B in ovaries and the temporal and spatial specificity of ZNF33B expression in early embryos. Secondly, the G-61G>T mutation of 5' UTR in ZNF33B gene was studied. The frequency of the G genotype was 0.3489 and that of the T genotype was 0.6511. This mutation was significantly correlated with the superovulation traits in cattle.
Jung-Keun Suh, Jae-Sung Lee, Hongsik Kong, Yoonseok Lee, and Hong-Gu Lee
Arch. Anim. Breed., 63, 417–422, https://doi.org/10.5194/aab-63-417-2020, https://doi.org/10.5194/aab-63-417-2020, 2020
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The relationship between HSPB1 expression and muscle growth in beef cattle has previously been reported, but there have been no reports of DNA markers related to meat quantity in Korean native steers. Therefore, the aim of this study was to evaluate the relationship of SNPs within HSPB1 in terms of the carcass traits related to muscle growth in Korean native steers.
Cui Mao, Xing Ju, Haijian Cheng, Xixia Huang, Fugui Jiang, Yuni Yao, Xianyong Lan, and Enliang Song
Arch. Anim. Breed., 63, 315–323, https://doi.org/10.5194/aab-63-315-2020, https://doi.org/10.5194/aab-63-315-2020, 2020
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To speed up the progress of marker-assisted selection (MAS) in cattle breeding, kinesin family member 1A (KIF1A) genes were chosen based on our previous genome-wide association study (GWAS) analysis results. We detected insertion/deletion (InDel) variation in these three candidate genes in 438 individual cattle (Xinjiang Brown cattle and Wagyu × Luxi crossbreed cattle). These findings may aid future analyses of InDel genotypes in cattle breeds and speed up the progress of MAS in cattle breeding.
Ishaku L. Haruna, Sibusiso A. Hadebe, Oyekunle J. Oladosu, Ghassan Mahmoud, Huitong Zhou, and Jon G. H. Hickford
Arch. Anim. Breed., 63, 241–248, https://doi.org/10.5194/aab-63-241-2020, https://doi.org/10.5194/aab-63-241-2020, 2020
Maria Ledinek, Leonhard Gruber, Franz Steininger, Birgit Fuerst-Waltl, Karl Zottl, Martin Royer, Kurt Krimberger, Martin Mayerhofer, and Christa Egger-Danner
Arch. Anim. Breed., 62, 491–500, https://doi.org/10.5194/aab-62-491-2019, https://doi.org/10.5194/aab-62-491-2019, 2019
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The aim of this study was to evaluate the influence of body weight on the efficiency of dairy cows. Data were derived from 161 commercial Austrian dairy farms. An optimum body weight range for efficiency does exist as the relationship of milk yield and body weight is nonlinear. Specialized dairy breeds seem to respond more intensively to body weight range than dual-purpose breeds. Cows with medium weights are the most efficient. A further increase in dairy cows’ body weights should be avoided.
Marwa Grayaa, Sylvie Vanderick, Boulbaba Rekik, Abderrahman Ben Gara, Christian Hanzen, Siwar Grayaa, Rodrigo Reis Mota, Hedi Hammami, and Nicolas Gengler
Arch. Anim. Breed., 62, 153–160, https://doi.org/10.5194/aab-62-153-2019, https://doi.org/10.5194/aab-62-153-2019, 2019
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The lactation curve and lactation survival are important in dairy cattle breeding. Their simultaneous improvement results in economic benefits. The genetic relationship between the lactation survival and the lactation curve shape traits of milk yield and fat and protein percentages using information from of 25 981 primiparous Tunisian Holsteins was investigated. Cows that had higher persistencies for fat and protein percentages were more likely not to survive.
Maria Selvaggi, Claudia Carbonara, Francesca Ciotola, Sara Albarella, Giulio Aiudi, Vincenzo Tufarelli, and Cataldo Dario
Arch. Anim. Breed., 62, 107–112, https://doi.org/10.5194/aab-62-107-2019, https://doi.org/10.5194/aab-62-107-2019, 2019
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The aims of the study were to estimate allele and genotype frequencies at g.-274C > G locus in the promoter region of the SIRT1 gene and to investigate, for the first time, the relationship among different genotypes and milk and reproduction traits in the Agerolese cattle breed. The investigated population was found to be polymorphic at the investigated locus. Concerning milk production performance, significant differences between genotypes were found.
Agus Susanto, Suyadi, Veronica Margareta Ani Nurgiartiningsih, and Luqman Hakim
Arch. Anim. Breed., 61, 491–496, https://doi.org/10.5194/aab-61-491-2018, https://doi.org/10.5194/aab-61-491-2018, 2018
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Improved milk yield in dairy cows results in worsening health and reproduction. Some linear traits are genetically associated with health and reproduction and can be used to assist selection programs. The National Breeding Centre for Dairy and Forage of Indonesia has not included linear traits in the breeding program. This study estimates genetic parameters of linear traits. The traits under study were found to be heritable and can be included in the breeding program along with milk yield.
Leonhard Gruber, Maria Ledinek, Franz Steininger, Birgit Fuerst-Waltl, Karl Zottl, Martin Royer, Kurt Krimberger, Martin Mayerhofer, and Christa Egger-Danner
Arch. Anim. Breed., 61, 413–424, https://doi.org/10.5194/aab-61-413-2018, https://doi.org/10.5194/aab-61-413-2018, 2018
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The objective of this study was to predict dairy cows' body weight from body size measurements. Body weight is an important trait for both management and breeding. Data were derived from 167 commercial Austrian dairy farms. To ensure high prediction accuracy, the use of a combination of both heart girth and belly girth is recommended if the use of scales is impossible. The large and heterogeneous data set supported a valid prediction.
Laura Viviana Santos, Kerstin Brügemann, Asja Ebinghaus, and Sven König
Arch. Anim. Breed., 61, 161–171, https://doi.org/10.5194/aab-61-161-2018, https://doi.org/10.5194/aab-61-161-2018, 2018
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The impact of the milking technique on the individual animal and the reaction of the animal on the technique were investigated. With the use of objectively recorded data from automatic milking systems (AMSs), auxiliary traits that reflect animal behavior in the milking system were defined, free from subjective impressions of classifiers. There is an apparent possibility to breed cows for AMS systems based on AMS data, though it is imperative to have further validation based on larger datasets.
Seyni Siddo, Nassim Moula, Issa Hamadou, Moumouni Issa, Salissou Issa, Marichatou Hamani, Pascal Leroy, and Nicolas Antoine-Moussiaux
Arch. Anim. Breed., 61, 143–151, https://doi.org/10.5194/aab-61-143-2018, https://doi.org/10.5194/aab-61-143-2018, 2018
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The complex balance between innovation and conservation regarding animal genetic resources makes it difficult to find mutually accepted improvement pathways between breeders, government agencies, and research and education institutions. This study maps stakeholder viewpoints on cattle genetic improvement in Niger using the Q method, which appears effective in identifying the concerns of stakeholders on complex agricultural innovation topics.
Danny Arends, Deike Hesse, and Gudrun A. Brockmann
Arch. Anim. Breed., 61, 87–98, https://doi.org/10.5194/aab-61-87-2018, https://doi.org/10.5194/aab-61-87-2018, 2018
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In this invited review we discuss the value of mice in improving livestock breeding. This review gives an overview of currently available databases for mice that can be used in livestock genetics research. Furthermore, this paper describes how different mouse models have contributed to livestock research in the past.
Allison Fleming, Emhimad A. Abdalla, Christian Maltecca, and Christine F. Baes
Arch. Anim. Breed., 61, 43–57, https://doi.org/10.5194/aab-61-43-2018, https://doi.org/10.5194/aab-61-43-2018, 2018
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Dairy cattle breeders have exploited technological advances in regard to reproduction and genomics. The implementation of such technologies in routine breeding programs has permitted genetic gains in traditional milk production traits as well as, more recently, in low heritability traits like health and fertility. Here we review a number of technologies that have helped shape dairy breeding programs in the past and present, along with those potentially forthcoming.
Sena Ardicli, Hale Samli, Deniz Dincel, Bahadir Soyudal, and Faruk Balci
Arch. Anim. Breed., 60, 303–313, https://doi.org/10.5194/aab-60-303-2017, https://doi.org/10.5194/aab-60-303-2017, 2017
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The impact of polymorphisms of the calpain 1 (CAPN1), calpastatin (CAST), leptin (LEP) and growth hormone receptor (GHR) on carcass characteristics and meat quality traits in 400 purebred Holstein bulls was examined using polymerase chain reaction and restriction fragment length polymorphism method. In the current study, the CAPN1, CAST and GHR genotypes confirmed significant associations with important traits in adequate numbers of animals.
Sena Ardicli, Deniz Dincel, Hale Samli, and Faruk Balci
Arch. Anim. Breed., 60, 61–70, https://doi.org/10.5194/aab-60-61-2017, https://doi.org/10.5194/aab-60-61-2017, 2017
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The present study was based on the association of polymorphisms at LEP, CAST, CAPN1, GHR, FABP4 and DGAT1 genes with fattening performance and carcass traits in Simmental bulls. Results indicated that final weight, fattening period, total weight gain and average daily gain differentiated the CAST and CAPN1 marker genotypes. Moreover, a novel effect of the LEP A80V on carcass weight and dressing percentage was observed. The results could be indicative for future studies on beef production.
Eva Strapáková, Juraj Candrák, and Peter Strapák
Arch. Anim. Breed., 59, 329–335, https://doi.org/10.5194/aab-59-329-2016, https://doi.org/10.5194/aab-59-329-2016, 2016
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The advantages of increasing lactation persistency in dairy cattle are indisputable on the practical herd level. More persistent lactation brings a longer high-production period. In this study estimate the breeding values of lactation persistency, test day of milk yield, somatic cell score, reproductive traits (calving interval, days open), and longevity in Slovak Holstein dairy cattle were estimated and the relationship between persistency of lactation and other selected trait was analyzed.
Xiaojuan Long, Xibi Fang, Ping Jiang, Hang Xiao, Haibin Yu, Mengjiao Zhou, Yunzhi Pan, Chunyan Lu, Zhihui Zhao, and Runjun Yang
Arch. Anim. Breed., 59, 301–307, https://doi.org/10.5194/aab-59-301-2016, https://doi.org/10.5194/aab-59-301-2016, 2016
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AGPAT6 is a key candidate gene in the lipid metabolism pathway. We detected two single nucleotide polymorphisms (SNPs) in bovine AGPAT6 exons, and we analyzed 33 traits associated with meat quality and the carcass of Chinese Simmental cattle. SNP1 was significantly associated with back fat thickness and fat coverage rate. SNP2 was significantly associated with fat coverage rate and marbling score. Thus, the SNPs of AGPAT6 may be genetic factors influencing carcass composition of beef cattle.
Hafedh Ben Zaabza, Abderrahmen Ben Gara, Hedi Hammami, Mohamed Amine Ferchichi, and Boulbaba Rekik
Arch. Anim. Breed., 59, 243–248, https://doi.org/10.5194/aab-59-243-2016, https://doi.org/10.5194/aab-59-243-2016, 2016
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A Bayesian and REML analyses were used on Tunisian dairy cattle data. Genetic parameters for 305-day milk, fat, and protein yields were estimated. Heritability estimates by using Bayesian method ranged from 0.187 to 0.273, and slightly higher than the corresponding REML. Large genetic correlations (> 0.88) among milk, fat, and protein yields were found for the two methods. This study suggests that results from both methods were reasonably similar to suggest both methods can be used.
Hafedh Ben Zaabza, Abderrahmen Ben Gara, Hedi Hammami, Borni Jemmali, Mohamed Amine Ferchichi, and Boulbaba Rekik
Arch. Anim. Breed., 59, 209–213, https://doi.org/10.5194/aab-59-209-2016, https://doi.org/10.5194/aab-59-209-2016, 2016
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Genetic parameters for 11 456 Tunisian Holstein cows were estimated for the following five reproductive traits: calving interval (CI), calving to first service interval, calving to conception interval (CCI), first service to conception interval and number of services per conception. Low heritabilities were estimated for these traits, and genetic correlation estimates between them were moderately high. The CCI–CI genetic correlation was 0.85, indicating that they are the same trait genetically.
K. Abfalter, W. Brade, and O. Distl
Arch. Anim. Breed., 59, 71–77, https://doi.org/10.5194/aab-59-71-2016, https://doi.org/10.5194/aab-59-71-2016, 2016
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Estimated breeding values (EBVs), relative breeding values (RBVs), and daughter yield deviations of Holstein cows with exceptional longevity (more than nine lactations completed) and the RBVs of their sires were analyzed. Exceptional cows had on average significantly lower EBVs for yield traits but significantly higher RBVs for somatic cell score (RZS) and functional longevity (RZN). Correlations among the proportion of exceptional cows per sire and RZN, RZS as well as fitness were positive.
Cited articles
Allaire, F. R. and Gibson, J. P.: Genetic value of herd life adjusted for milk production, J. Dairy Sci., 75, 49–56, 1992.
Boettcher, P. J., Jairath, L. K., and Dekkers, J. C. M.: Comparison of methods for genetic evaluation of sires for survival of their daughters in the first three lactations, J. Dairy Sci., 82, 34–44, 1999.
Bonetti, O., Rossoni, A., and Nicoletti, Ch.: Genetic parameters estimation and genetic evaluation for longevity in Italian Brown Swiss bulls, Ital. J. Anim. Sci., 8, 30–32, 2009.
Caraviello, D. Z., Weigel, K. A., and Gianola, D.: Prediction of longevity breeding values for US Holstein sires using survival analysis methodology, J. Dairy Sci., 87, 18–25, 2004.
Caraviello, D. Z., Weigel, K. A., Shook, G. E., and Ruegg, P. L.: Assessment of the impact of somatic cell count on functional longevity in Holstein and Jersey cattle using survival analysis methodology, J. Dairy Sci., 88, 4–11, 2005.
Chirinos, Z., Hernández, D., and Carabaño, M. J.: Effect of somatic cell scores on functional longevity of dairy cattle assessed by survival analysis, Arch. Latinoam. Prod. Anim., 13, 56–62, 2005.
Chirinos, Z., Carabano, M. J., and Hernandez, D.: Genetic evaluation of length of productive life in the Spanish Holstein-Friesian population. Model validation and genetic parameters estimation, Livest. Sci., 106, 120–131, 2007.
Cox, D. R. and Oakes, D.: Analysis of Survival Data, Chapman and Hall Publications, London, 1984.
De Vliegher, S., Barkema, H. W., Stryhn, H., Opsomer, G., and de Kruif, A.: Impact of early lactation somatic cell count in heifers on milk yield over the first lactation, J. Dairy Sci., 88, 38–47, 2005.
Ducrocq, V.: Statistical analysis of length of productive life for dairy cows of the Normande breed, J. Dairy Sci., 77, 55–66, 1994.
Ducrocq, V. and Solkner, J.: “The survival Kit-V3.0” A package for large analysis of survival data, 6th World Congress Genet. Appl. Armidale, NSW, Australia, 47–48, 1998.
Ducrocq, V., Quaas, R. L., Pollack, E. J., and Casella, G.: Length of productive life of dairy cows. Variance component estimation and sire evaluation, J. Dairy Sci., 71, 3071–3079, 1988.
Ducrocq, V., Quaas, R. L., Pollak, E. J., and Casella, G.: Length of productive life of dairy cows. Justification of a Weibull Model, J. Dairy Sci., 71, 61–70, 1998.
Ducrocq, V., Solkner, J., and Meszaros, G.: The Survival Kit v6.0, User's Manual, 68 pp., 2010.
Dürr, J. W. H., Monardes, G., and Cue, R. I.: Genetic analysis of herd life in Quebec Holsteins using Weibull models, J. Dairy Sci., 82, 3–13, 1999.
Haile-Mariam, M., Bowman, P. J., and Goddard, M. E.: Genetic and environmental relationship among calving interval, survival, persistency of milk yield and somatic cell count in dairy cattle, Livest. Prod. Sci., 80, 189–200, 2003.
M'Hamdi, N., Aloulou, R., Bouallegue, M., Brar, S. K., and Hamouda M. B.: Study on functional longevity of Tunisian Holstein dairy cattle using a Weibull proportional hazard model, Livest. Sci., 132, 3–6, 2010.
Novaković, Ž., Aleksić, S. L., Sretenović, M. M., Petrović, V., Pantelić, V., and Ostojić-Andrić, D.: Longevity of high-yielding cows, Biotech. Anim. Husbandry, 45–54, 2009.
Pedersen, J. and Christensen, L. G.: Heterosis for milk production traits by crossing Red Danish, Finnish Ayrshire and Holstein-Friesian cattle, Livest. Prod. Sci., 23, 253–266, 1989.
Potocnik, K., Gantner, V., Krsnik, J., Stepec, M., Lgar, B., and Gorjanc, G.: Analysis of longevity in Slovenian Holstein Cattle, Archiv Agric. Slovenica, 98, 93–100, 2011.
Roche, J. F.: The effect of nutritional management of the dairy cow on reproductive efficiency, Anim. Reprod. Sci., 96, 282–296, 2006.
Raguz, N., Jovanovac, S., Gantner, V., Mészáros, G., and Sölkner, J.: Analysis of factors affecting the length of productive life in Croatian dairy cows, Bulg. J. Agri. Sci., 17, 32–40, 2011.
Sewalem, A., Kistemaker, G. J., and Van Doormaal B. J.: Relationship between type traits and longevity in Canadian Jerseys and Ayrshires using a weibull proportional hazards model, J. Dairy Sci., 88, 52–60, 2005a.
Sewalem, A., Kistemaker, G., Miglior, J. F., and Van Doormaal, B. J.: Genetic analysis of herd life in Canadian dairy cattle on a lactation basis using a weibull proportional hazards model, J. Dairy Sci., 88, 68–75, 2005b.
Sørensen, M. K., Norberg, E., Pedersen, J., and Christensen, L. G.: Invited Review: Crossbreeding in Dairy Cattle: A Danish Perspective, J. Dairy Sci., 91, 4116–4128, 2008.
Strapakova, E., Strapak, P., and Candrak, J.: Estimation of breeding values for functional productive life in the Slovak Holstein population, Czech J. Anim. Sci., 59, 54–60, 2014.
Van Arendonk, J. A. M.: Use of profit equations to determine relative economic value of dairy cattle herd life and production from field data, J. Dairy Sci., 74, 1–7, 1991.
Van der Linde, C. and De Jong, G.: MACE for longevity traits, Proc. Interbull Technical Workshop, Beltsville, MD, USA, 2–3 March, 2003.
Van der Linde, C., De Jong, G., Simai, S. Z., Gombacsi, P., and Wellisch, P.: Genetic evaluation for longevity in Hungary, Proceedings of the 2006 Interbull meeting, Kuopio, 35, 3–7, 2006.
VanRaden, P. M. and Wiggans, G. R: Productive life evaluations: Calculation, 86 accuracy and economic value, J. Dairy Sci., 78, 631–638, 1995.
Vollema, A. R. and Groen, A. F.: A comparison of breeding value predictors for longevity using a linear model and survival analysis, J. Dairy Sci., 81, 15–20, 1998.
Vukasinovic, N.: Application of survival analysis in breeding for longevity, Proceedings international workshop on EU concerted action Genetic Improvement of Functional Traits in Cattle (GIFT), Jouy-en-Josas, 21, 3–10, 1999.
Vukasinovic, N., Moll, J., and Künzi, N.: Analysis of productive life in Swiss Brown Cattle, J. Dairy Sci., 80, 2–9, 1997.
Vukasinovic, N., Moll, J., and Casanova, L.: Implementation of a routine genetic evaluation for longevity based on survival analysis techniques in dairy cattle populations in Switzerland, J. Dairy Sci., 84, 73–80, 2001.
Yazdi, M. H., Visscher, P. M., Ducrocq, V., and Thompson, R.: Heritability, reliability of genetic evaluations and response to selection in proportional hazard models, J. Dairy Sci., 85, 1563–1577, 2002.
Short summary
This study aimed to use survival analysis and examine the factors affecting functional herd life (FHL) of cows in Isfahan using the Weibull proportional risk model in Isfahan to estimate of breeding values for functional herd life. The SC, milk production, age at first calving and milk period showed significant effects on LPL (P < 0.001) according to the likelihood ratio test. Although there were some fluctuations in genetic trends, an overall increase was observed which leads to a longer FHL
This study aimed to use survival analysis and examine the factors affecting functional herd life...
