of inseminators. When comparing herd
performance, the number of natural services
should also be considered as that would
reduce (or improve) the average SPC figure.
To determine heat detection efficiency, two
indicators can be used, i.e. the number of
days from CFS and the average number of
days between heats (breeding interval). The
proportion of CFS intervals within 80 days
after calving also gives an indication of heat
detection. Breeding interval (BI) is estimated
by subtracting the CFS interval from the
interval between calving date and conception
date (DO) and dividing that by the number of
SPC minus one, i.e. (DO-CFS)/(SPC-1). Dividing
21 by BI gives the heat detection efficiency,
i.e. for a BI of 42 days, heat detection is 50%
which means that only every second heat
was observed. The most accurate way is to
estimate the average number of days between
heats by using service dates for each cow.
To evaluate the performance of heat spotters
and inseminators, records of all cows in
the herd should be used. Results should be
presented on an ongoing basis in graphs
showing the trend for each worker over time.
In closing
Establishing the standard of reproduction
management of dairy farmers is a first step
towards improving fertility in dairy cows.
Poor reproduction management may induce
infertility in otherwise fertile cows. Ways to
improve fertility in dairy herds depends on (i)
a short term plan such as providing a clean,
dry and sunny calving down area, monitoring
cows post calving for early detection of uterine
infections, checking heat cycling performance
of cows within the first 80 days after calving;
(ii) a medium term plan such as having an
action plan for cows more than 150 days in
milk not confirmed pregnant, having a heat
detection programme in place, ongoing
checking of AI techniques (or performance)
of inseminators, checking semen quality
and (iii) a long term plan by using sires for AI
with breeding information such as daughter
pregnancy rates and productive life estimated
breeding values.
Onoortreflike gehalte en professionele diens - in Suid-Afrika geteel vir Suid-Afrikaanse vlieë
Hoe werk hierdie program?
Vliegparasiete ( Muscidifurax raptor) word in ‘n
insektarium geteel en is beskikbaar in pakkies van
5 000. Hierdie parasitiese wespes word gereeld
by vliegbroeiplekke op die plaas losgelaat.
Die volwasse wesp steek die papie van die vlieg,
dood dit in die proses en lê eiers in die papie. Die
eiers teer op die dooie vliegpapie en ontwikkel
in ‘n wespe. Die wespe broei binne 19-21 dae
uit en begin dan die soektoeg na vliegpapies as
voedsel en waarin hulle kan eiers lê.
www.bioinsectsa.com
AgriKultuur
|AgriCulture
BISA bied u:
Vliegbeheer op die natuurlike manier.
Langtermyn ekonomiese voordele.
Minder chemiese besoedeling.
‘n Bemarkingsvoordeel deur omgewings-
vriendelike landbouproduksie.
SLIM
BEHEER VAN VLIEË
BISA het agente landswyd.
Vir meer inligting, nader:
Besturende direkteur
Arno Moore (PhD)
Sel 083 270 4866 | Epos
[email protected]
Kantoor
Helouise Rumbles
Sel 083 5664784 | E-pos
[email protected]
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