Output is vanity and profit is sanity in the eyes of today’s business-minded dairy owners and managers.
Detailed budgets in many commercial herds indicate that crossbred cows will make at least 75 £ (100 €) more net revenue per cow per year than the most competitive purebreds. This increase in net revenue is driven by improved fertility, decreased health costs, and, in some crosses, lower feed costs. Read more to see why crossbreeding in commercial dairy herds continues to grow in North America, Europe and other highly developed dairy industries.
Background
Knowledgeable dairy producers around the world continue to adopt crossbreeding as a routine programme for their herds. Approximately 50% of the current dairy calves in New Zealand are crossbreds and this number is increasing each year. In the United States (US) the percentage of crossbreds is between 5% and 10% (over 500,000 crossbred cows) and increasing almost 1% per year. Here in the UK it is estimated that 5 to 7% of cows are crossbred (higher if one includes Friesian by Holstein as crosses). Crossbreeding is not a "fad" but it is now the accepted approach to breeding in progressive, commercial dairy herds.
Benefits of crossbreeding
One of the critical benefits of crossbreeding is heterosis or hybrid vigor. Heterosis results when we cross individuals from different breeds, cultivars, strains or species. Heterosis is the difference between the performance of crossbred offspring compared to the average of their parents. Heterosis tends to increase as the genetic relationship between the parental breeds increases so parents that are genetically more distinct will produce offspring with a higher level of heterosis.
As an example, North American strains of Holsteins and European Friesians such as British Friesians have been separated by many generations and we do see some heterosis when crossing Holsteins and Friesians. However, the crossing of Holsteins with Friesians results in about ½ the heterosis that we see from crossing more distinct breeds.
In general, fitness traits benefit more via heterosis than production traits. Crossbred cows in New Zealand stay in the herd approximately one lactation longer than purebreds due to heterosis. Heterosis from crossing different breeds in the US results in 6 fewer days open and over 200 kg more milk per lactation.
More heterosis results when more breeds are added to the crossbreeding programme but more breeds may be undesirable if the additional breeds do not fit your system or have poor overall dairy performance. It is critical that the appropriate breeds (and number) be chosen for the programme.
In addition to heterosis, crossbreeding can produce benefits due to complementarity. Improvements in overall performance of crossbred offspring can result from crossing breeds that complement each other. A good example of complementarity would be the crossing of Norwegian Reds with Holsteins to moderate the size of Holsteins to fit various systems.
The global Holstein breeding programme is much larger than any other breed but the direction of the programme in the past has lead to declines in fertility and health traits. Some breeds have balanced production with fertility and health, most notably in the Nordic countries where large, extremely accurate programmes have focused on production and fitness traits for many generations. For example, Norway, who has the largest Red cattle breeding programme of all the Nordic countries, has selected the Norwegian Red breed for improved cow fertility based on sire progeny testing for more than 35 years. The Norwegian progeny testing programme tests 125 Norwegian Red sires annually with first crop progeny group sizes that approach 250 daughters per bull.
Unfortunately, the global Holstein population declined steadily in fertility from 1960 until the early to mid 2000s (see Figure 1 for US data). Since the early to mid 2000s Holstein breeding programmes have been able to stop the genetic decline in fertility. However, even if significant changes were made in the current breeding policy by placing much more emphasis on cow fertility (and less on production and other traits), it would take at least 20 to 30 years to get the Holstein breed back to the fertility levels they enjoyed 30 years ago.
Figure 2 shows the level of performance for crossbred daughter pregnancy rate (the US measure of cow fertility) of various breeds imported into the US in recent years (data from the most recent US Department of Agriculture genetic evaluations). The crossbred daughters are compared to the current US Holstein genetic base, i.e. average Holstein cow born in 2005 = 0.0. Each unit of daughter pregnancy rate represents about 4 days open. Crossbred daughters of the other breeds have outstanding fertility compared to Holsteins.
In the UK, Mark Birkett from White Lund Farm in Lancashire, who milks 300 cows, says "Looking back in my records, my crosses have a 15% improvement in conception to first service with similar production levels as Holsteins, and this is proof enough that they are more fertile."
Crossbred daughters of some bulls produce as much milk as daughters of the highest Holstein sires. Richard Park from Cumbria with 150 cows remarks "Our whole herd is crossbreds and we are milking a number of 3 way crosses. With our rolling herd average about 9200 kgs and a calving index of around 368 days for the last number of years we are very pleased. This year we have changed to Autumn block calving and selling off cattle as a result. The sales value and interest in our surplus cows is very much appreciated."
In the U.S., the Norwegian Red sire 5848 Oygarden has many milking daughters in the US. Oygarden ranks (based on his Predicted Transmitting Abilities on the US Holstein base and heterosis) in the top 1% of all progeny tested Holstein sires for fat and protein production and in the top 20% for milk yield. And of course Oygarden is better than all the current progeny tested Holstein bulls in the US for daughter pregnancy rate. As in all breeding programmes it is important to select bulls that fit your needs and to choose breeds that complement and fit your system.
Research has proven that crosses will have lower cull rates for fertility and health problems, lower veterinary expenses and more importantly, they will have lower mortality rates in both calves and in adult cows. As a result, crossbreds are much simpler and easier to manage, more "trouble free" and less frustrating.
This article is also published in the latest printed issue of British Dairying
Another related article from Gary W. Rogers and Joan B. Cooper:
USDA genetic evaluations for imported red sires
Note: Dr. Rogers has been recognized by the American Dairy Science Association for his outstanding research work in dairy cattle breeding and genetics. In 1998 was recognized for his outstanding leadership as a genetics researcher and was awarded the coveted J. L. Lush Award in Animal Breeding. Gary works with a number of large herds in the U.S. in evaluating and developing cross breeding programmes.