Crossbreeding of Holstein cows improves fertility without detriment to
milk production

Date:
August 24, 2020
Source:
Elsevier
Summary:
Since 1960, Holstein dairy cows have exhibited a substantial
decline in fertility, with serious economic consequences for
farmers. Genetic selection programs in the United States and
elsewhere have emphasized milk production at the expense of
other traits. Attention has turned to improving these neglected
traits for better overall well-being of cows and to ameliorate
dairy producers' profitability. Scientists have now examined the
effects of crossbreeding on fertility and milk production across
three generations in a large sample of Holstein and crossbred cows.



FULL STORY ========================================================================== Since 1960, Holstein dairy cows have exhibited a substantial decline
in fertility, with serious economic consequences for farmers. Genetic
selection programs in the United States and elsewhere have emphasized
milk production at the expense of other traits. Attention has turned to improving these neglected traits for better overall well-being of cows
and to ameliorate dairy producers' profitability. In a recent article
appearing in the Journal of Dairy Science, scientists from the University
of Minnesota examined the effects of crossbreeding on fertility and milk production across three generations in a large sample of Holstein and
crossbred cows.


========================================================================== Although in recent years Holstein breeding programs have made strides
toward remedying the problem of diminished fertility, crossbreeding is
often seen as a possible means to achieve greater and more rapid gains,
while eliminating concerns about inbreeding.

"A larger response in phenotypic fertility will be experienced over a
shorter period of time from crossbreeding than from selection within
a pure Holstein population," explained lead author Amy Hazel, PhD,
University of Minnesota, St.

Paul, MN, USA. Whether this is true, and whether crossbred cows can
compete with Holsteins in a high-producing commercial dairy setting,
were questions that the team investigated.

Purebred Holsteins were compared with cows from a three-breed rotation
of Holstein with Viking Red and Montbe'liarde in this 10-year study with initial enrollment of 3,550 Holstein cows from Minnesota commercial
dairies. The team found that each combination of two- and three-breed
crossbred cows demonstrated significant advantages over pure Holsteins
for all fertility traits at each studied lactation. This confirmed expectations, but what about the possibility that milk production might be negatively affected by crossbreeding? "Because of the global predominance
of high-producing Holsteins, some dairy producers have been concerned
that crossbred cows will have poorer milk production traits," observed
Prof. Hazel. "But our study found little, if any, loss of fat and protein production for crossbred cows compared with their Holstein herdmates."
As dairy producers place increased emphasis on minimizing the major
expenses for cows -- including feed intake, repeated inseminations,
health treatments, and premature replacement -- this large and carefully designed study confirms that strategic crossbreeding can improve fertility
of dairy herds, reduce costs of insemination, and result in more efficient
milk production, without significant losses in milk composition.

Additionally, a larger effect should be the longer herd life of crossbred
cows compared with pure Holsteins. Although further research remains to
be performed, this study establishes the Viking Red and Montbe'liarde
breeds as highly complementary for crossbreeding with Holsteins and well
suited for milk production in high-performance dairy herds.


========================================================================== Story Source: Materials provided by Elsevier. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. A.R. Hazel, B.J. Heins, L.B. Hansen. Fertility and 305-day
production of
Viking Red-, Montbe'liarde-, and Holstein-sired crossbred cows
compared with Holstein cows during their first 3 lactations in
Minnesota dairy herds. Journal of Dairy Science, 2020; 103 (9):
8683 DOI: 10.3168/ jds.2020-18196 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200824120036.htm

--- up 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)