A growing body of evidence is demonstrating that crossbred cattle are significantly more fertile than the pure Holstein. Their improved fertility has been shown to be achieved without any compromise to their milk production.
A succession of investigations into the performance of the Holstein x Montbéliarde x VikingRed has found the three-breed cross to perform better than the purebred for every measure of fertility. It has achieved this feat whilst producing almost the same weight of fat plus protein as the pure Holstein.
The latest study to confirm this message is reported in the prestigious, peer-reviewed Journal of Dairy Science, (103:8683-8697, September 2020). Undertaken as part of a 10-year study at the University of Minnesota, it investigated the performance of cattle bred using the Holstein (HO), Montbéliarde (MO) and VikingRed (VR), now marketed as the ProCROSS programme.
Commenting on the fertility of the ProCROSS, the study’s lead author, Dr Amy Hazel, said: “For every parameter we looked at, the crossbreds were overwhelmingly better than their Holstein herdmates.”
For example, the three-breed crossbreds had significantly higher (+9% to +10%) first service conception rates. They also had lower ages at first, second and third calving; significantly fewer (-16.5) days open over three lactations; and their advantage in days open increased to almost three weeks for their third lactations.
Furthermore, fat plus protein production (kg) in each of their first three lactations, was just 3-4% lower than the Holstein in the three-breed cross. However, when converted to a lifetime daily yield (LDY) of fat plus protein, the ProCROSS produced 2.537kg per day, only 1% lower than the 2.554kg per day of her Holstein herdmates.
“LDY is an important economic parameter, as it is influenced by a range of traits including conception rates, return to peak production and survival, all of which are influenced by the cow’s fertility,” continued Dr Hazel.
Following the three-breed cross on to the next generation revealed there was no difference in weight of fat plus protein between the third (Holstein-sired) cross of ProCROSS cattle and the pure Holstein.
All the crossbred generations also produced milk with higher percentages of fat and protein than their Holstein herdmates.
Dr Hazel said the better performance of the ProCROSS was also reflected in greater profitability –which was the subject of additional research at the University of Minnesota, and was expected to be published in detail in JDS over the coming months.
She said: “The immediate financial benefits of good fertility come largely through lower insemination, hormone treatment and pregnancy diagnosis costs.
“Fertility also has a direct and positive impact on lifespan,” she added. “This was seen in the ProCROSS cattle whose herdlife averaged 997 days, compared with 850 days for the Holstein – a lifespan advantage of 147 days.”
The extra lifespan also gave rise to lower replacement rates, which were important in lowering costs of production.
Dr Hazel attributed the crossbreeds’ advantage to the choice of complementary breeds alongside hybrid vigour (heterosis). The use of three breeds in rotation was said to maintain heterosis at a constant 86% in perpetuity, so giving the outcrossed animal better performance than the average of its parents.
She added: “We found the breeds used in the trial to be very complementary. The Holstein brings production and udder traits; the Montbéliarde brings fertility, body condition and strength; and the VikingRed brings calving traits, udder health and fertility. Furthermore, the three breeds are complementary for stature, helping to bring size uniformity and ease of management.”
The motivation for the trial was said to have come from concern over the narrowing of Holstein bloodlines, the resulting inbreeding depression and the desire to gain the benefits of hybrid vigour.
“The inbreeding coefficient in the USA’s Holstein population now exceeds 8% and continues to rise at a rate of 0.35% each year,” she said. “This inevitably results in inbreeding depression which silently steals profit from dairy producers, because it mostly affects traits which are not readily noticeable such as embryo loss, less disease resistance and shortened survival.”
This was clearly reflected in the newly published fertility results, while improved health, lower stillbirth rates and improved feed efficiency have also been demonstrated in ProCROSS cattle.
“This trial has demonstrated how the qualities of two complementary breeds can be blended with those of the Holstein to create more robust, fertile and long-living cattle which retain the production of the Holstein,” concluded Dr Hazel. “By choosing the Montbéliarde and VikingRed, we were introducing breeds whose strong-suits complemented those the Holstein lacks.
“As pressure increases on the finite resources we use for food production, our economic sustainability has to consider the expenses for feed, health care, fertility, herd replacements and labour. For this reason, genetic selection of dairy cattle must move its emphasis away from the single trait of milk production, and crossing these three breeds provides an effective means of achieving this,” she said.
For more information:
Stéphane Fitamant, Director of ProCROSS: s.fitamant@procross.info
Source
“Fertility and 305-day production of Viking Red-, Montbéliarde-, and Holstein-sired crossbred cows compared with Holstein cows during their first 3 lactations in Minnesota dairy herds”, by Dr. Amy Hazel, Dr. Brad Heins, and Dr. Les Hansen from the University of Minnesota, published in Journal of Dairy Science, Volume 103, Issue 09, September 2020, P8683-8697.
https://www.journalofdairyscience.org/article/S0022-0302(20)30505-1/fulltext
