Simulating consequences of choosing a breeding goal for organic dairy production.

In Denmark, Finland, and Sweden, the Nordic Total Merit index is used as the breeding selection tool for both organic and conventional dairy farmers based on common economic models for conventional dairy farming. Organic farming is based on the principles of organic agriculture (POA) defined by the International Federation of Organic Agriculture Movements. These principles are not set up with an economic point of view, and therefore it may be questionable to use a breeding goal (BG) for organic dairy production based on economic models. In addition to economics and the principles of organic agriculture, it is important to look at farmers' preferences for improving BG traits when setting up a BG for organic farming. The aim of this research was to set up, simulate, and compare long-term effects of different BG for organic and conventional dairy production systems based on economic models, farmers' preferences, and POA, with particular emphasis on disease resistance or on roughage consumption and feed efficiency. The BG based on economic models and on farmers' preferences were taken from previous studies. The other BG were desired gains indices, set up by means of a questionnaire about relatedness between the POA and BG traits. Each BG was simulated in the stochastic simulation program ADAM. The BG based on POA, with particular emphasis on disease resistance or on roughage consumption and feed efficiency, caused favorable genetic gain in all 12 traits included in this study compared with 6 traits for the other BG. The BG based on POA, with particular emphasis on disease resistance or on roughage consumption and feed efficiency, were very different from BG for organic and conventional production based on economic models and farmers' preferences in both simulated genetic change and correlations between BG. The BG that was created based on the principles of organic agriculture could be used as a specific index for organic dairy farming in Denmark, but this index was economically not very sustainable. Hence, an intermediate breeding goal could be developed by breeding companies to address both economics and the principles of organic agriculture.

[1]  A. C. Sørensen,et al.  Organic dairy farmers put more emphasis on production traits than conventional farmers. , 2016, Journal of dairy science.

[2]  M. Lidauer,et al.  Genetic parameters for dry matter intake in primiparous Holstein, Nordic Red, and Jersey cows in the first half of lactation. , 2016, Journal of dairy science.

[3]  A. C. Sørensen,et al.  Herd characteristics influence farmers’ preferences for trait improvements in Danish Red and Danish Jersey cows , 2016 .

[4]  M. Kargo,et al.  Avoiding double counting when deriving economic values through stochastic dairy herd simulation , 2016 .

[5]  S. Rensing,et al.  The genetic structure of longevity in dairy cows. , 2016, Journal of dairy science.

[6]  L. Rydhmer,et al.  Differences in preferences for breeding traits between organic and conventional dairy producers in Sweden , 2014 .

[7]  J. Woolliams,et al.  Direct and maternal genetic relationships between calving ease, gestation length, milk production, fertility, type, and lifespan of Holstein-Friesian primiparous cows. , 2013, Journal of dairy science.

[8]  G. Varga,et al.  Short communication: Feed utilization and its associations with fertility and productive life in 11 commercial Pennsylvania tie-stall herds. , 2013, Journal of dairy science.

[9]  Rex D. Fernando,et al.  Genetic parameters for energy balance, feed efficiency, and related traits in Holstein cattle. , 2012, Journal of dairy science.

[10]  A. C. Sørensen,et al.  Genomic selection strategies in dairy cattle: Strong positive interaction between use of genotypic information and intensive use of young bulls on genetic gain. , 2012, Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie.

[11]  G. Varga,et al.  Heritability of gross feed efficiency and associations with yield, intake, residual intake, body weight, and body condition score in 11 commercial Pennsylvania tie stalls. , 2011, Journal of dairy science.

[12]  M. K. Sørensen,et al.  Genetic analysis of calf and heifer losses in Danish Holstein. , 2010, Journal of dairy science.

[13]  L. Rydhmer,et al.  Fertility, somatic cell count and milk production in Swedish organic and conventional dairy herds , 2009 .

[14]  A. C. Sørensen,et al.  Factors affecting the exchange of genetic material between Nordic and US Holstein populations. , 2009, Journal of dairy science.

[15]  A. C. Sørensen,et al.  ADAM: A computer program to simulate selective-breeding schemes for animals , 2009 .

[16]  T. Mark,et al.  Genetic parameters for claw and leg health, foot and leg conformation, and locomotion in Danish Holsteins. , 2009, Journal of dairy science.

[17]  J. Weller,et al.  Genetic analysis of the growth rate of Israeli Holstein calves. , 2008, Animal : an international journal of animal bioscience.

[18]  E. Norberg,et al.  Genetic analysis of protein yield, udder health, and female fertility in first-parity Danish Holstein cows , 2008 .

[19]  J. Dekkers,et al.  Prediction of response to marker-assisted and genomic selection using selection index theory. , 2007, Journal of animal breeding and genetics = Zeitschrift fur Tierzuchtung und Zuchtungsbiologie.

[20]  R. Veerkamp,et al.  Optimization of dairy cattle breeding programs for different environments with genotype by environment interaction. , 2006, Journal of dairy science.

[21]  F. Miglior,et al.  Selection indices in Holstein cattle of various countries. , 2005, Journal of dairy science.

[22]  P M VanRaden,et al.  Development of a national genetic evaluation for cow fertility. , 2004, Journal of dairy science.

[23]  J. Jensen,et al.  Genetic parameters of production, feed intake, body weight, body composition, and udder health in lactating dairy cows , 2002 .

[24]  M. Lund,et al.  Genetic parameters of dairy character, protein yield, clinical mastitis, and other diseases in the Danish Holstein cattle. , 2002, Journal of dairy science.

[25]  Robin Thompson,et al.  Linear and threshold model genetic parameters for disease, fertility and milk production in dairy cattle , 2000 .

[26]  P. Berger,et al.  Genetic and phenotypic parameters for 305-day yield, fertility, and survival in Holsteins. , 1998, Journal of dairy science.

[27]  J. Jensen,et al.  Genetic and phenotypic parameters of lifetime and stayability traits in danish dairy breeds , 1998 .

[28]  J.A.M. van Arendonk,et al.  Genetic aspects of feed intake and efficiency in lactating dairy heifers , 1991 .

[29]  P. Oltenacu,et al.  Relationship of fertility to milk yield in Swedish cattle. , 1991, Journal of dairy science.