Article by Dr Carel Muller
Directorate: Animal Sciences, Research & Technology Development Services,
Elsenburg
M
ost dairy farmers
rear all the heifers
born in the herd to
first calving as they
are required to replace cows that,
over time, are culled from the herd.
This is preferred to the custom of
purchasing heifers from other producers for the following reasons:
Breeding a high producing dairy
herd requires the selection of
animals according to their production performance. For this
reason information on the pedigree and production records of
such animals is very important.
Information on dams and sire of
purchased heifers is sometimes
unavailable consequently their
genetic merit would be unknown.
Purchased animals may carry
infectious diseases like brucellosis (contagious abortion) and
bovine tuberculosis with them.
The purchase price of heifers is
often higher than own rearing
cost while also not in relation to
their eventual production performance.
Heifers are not always available
to buy when required in a herd.
For home-grown heifers forward
planning is easier because the
number of first lactation cows
entering the herd is known well
in advance.
Heifers reared locally are usually
adapted to a particular farm’s
environment and management.
Feeding programme
Feeding is the single most important factor affecting the growth
rate of heifers. Reaching minimum
live weights at a specific age is important in heifer rearing as this is
an indication of their physiological
and skeletal development. For heifers, both over- and underfeeding is
detrimental. As the nutritional requirements of heifers increase as
they become older, their feeding