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Discipline: breeding; Key words: dairy crossbreeding, animal performance, profitability, modelling.
Efficient control of fertility and health is a main target to increase profitability of dairy operations, due to the economic impact of poor fertility or poor health performance. Another target to increase profitability is better milk prices by increasing milk solid contents. For Holstein dairy operations, these two targets are particularly relevant. Within the Holstein, genetic improvement of these traits is possible; for example according to the international literature, reproductive and health genetic merit of Holstein cows has slightly increased in the past 10 years. Nevertheless, given the superiority of milk solids, reproduction and health traits of several other dairy breeds, dairy crossbreeding might be an alternative option to pure breeding. To test this hypothesis, Dr C. Dezetter and colleagues in France used a comprehensive simulation model to assess the economic effects resulting from changes in performance for milk yield and solid contents, reproduction, health and replacement, induced by the introduction of crossbreeding in Holstein dairy operations. Their results were published in the Journal of Dairy Science, Volume 100 of 2017, pages 8239 to 8264, the title of the paper being: Changes in animal performance and profitability of Holstein dairy operations after introduction of crossbreeding with Montbéliarde, Normande, and Scandinavian Red.
Three crossbreeding schemes, Holstein × Montbeliarde, Holstein × Montbeliarde × Normande, and Holstein × Montbeliarde × Scandinavian Red were implemented in Holstein dairy operations and compared with Holstein pure breeding, with milk production levels up to 9000L per cow-year. Sires were selected based on their estimated breeding value for milk. Two initial operations were simulated according to the prevalence (average or high) of reproductive and health disorders in the lactating herd. The model simulation was run for an extrapolated 15 year period using two alternative managerial objectives, constant number of cows or constant volume of milk sold.
The results showed that after 15 years, breed percentages reached equilibrium for the 2-breed but not for the 3-breed schemes. After 5 years of simulation, the 3 crossbreeding schemes reduced average milk yield per cow-year compared with the pure Holstein scheme. Changes in other animal performance parameters (milk solid contents, reproduction, udder health and longevity) were always in favour of the crossbreeding schemes. For the objective of a constant number of cows, the margin over variable costs over the 15 year of simulation was slightly increased by the crossbreeding schemes, with an average prevalence of disorders up to €32 per cow-year. In operations with a high prevalence of disorders, the crossbreeding schemes increased the margin over variable costs up to €91 per cow-year. For the objective of a constant volume of milk sold, the crossbreeding schemes improved the margin over variable costs up to €10 per 1000L (corresponding to about €96 per cow-year) for an average prevalence of disorders and up to €13 per 1000L (corresponding to about €117 per cow-year) for a high prevalence of disorders. For the objective of a constant number of cows, an unfavourable pricing context (milk price vs. concentrates price) had a slight positive effect on margin over variable costs for crossbreeding. For the objective of a constant volume of milk, only very limited changes in differences of margins were found between the breeding schemes.
The results should be seen as conditional, as they were obtained with a particular set of simulations under French conditions. They nevertheless suggest that dairy crossbreeding should be considered as a relevant option for Holstein dairy operations with a milk production level of up to 9000 kg per cow-year.