2006/2007 Field Trial
Data - Use of
HeiferPlusTM in Virgin
Heifers
Introduction:
On-farm breeding trials
were done in 2006 and
2007 using HeiferPlusTM
to sex bull semen.
Mostly virgin Fresian-
Holstein heifers were
used in the trials.
Normal heifer management
practices were followed.
Heifers were
artificially bred at 12
hrs following first
observed tanding estrus.
AIl inseminations were
done with a standard
1/2cc
single dose of
frozen-hawed bull semen
treated with
HeiferPlusTM.
|
TRIAL # |
YEAR |
# of CALVES |
MALES |
% |
FEMALES |
% |
|
1 |
06 |
20 |
1 |
5% |
19 |
95% |
|
2 |
06 |
14 |
2 |
14% |
12 |
86% |
|
3 |
06 |
10 |
4 |
40% |
6 |
60% |
|
4 |
06 |
6 |
2 |
33% |
4 |
67% |
|
5 |
07 |
8 |
2 |
25% |
6 |
75% |
|
6 |
07 |
10 |
3 |
30% |
7 |
70% |
|
TOTAL |
|
68 |
14 |
21% |
54 |
79% |
Results:
Table 1 (above) shows
the results of six
on-farm breeding trials.
In Trial 1, 20 calves
were produced, 1 (5%)
was
ale and 19 (95%) were
female. In Trial 2, 14
calves were born, 2
(14%) were male and 12
(86%)were female. In
trial
3, 10 calves were
produced, 4 (40%) male
and 6 (60%) female. In
Trial 4, there were 6
calves produced, 2 male
33%) and 4 (67%) female.
In Trial 5, there were 9
pregnancies produced.
Ultrasound sexing
results at 60
days revealed 2 males
(25%) and 6 females
(75%) and one unknown.
In Trial 6, of 10
calves, 3 (30%) were
male and
(70%) were female.
The combined sex ratio
from the six trials was
14( 21%) male and 54
(79%) female. A
statistical analysis of
the
combined results
(Chi-square, X2 =
(O-E)2/E) and assuming a
normal 48% female sex
ratio, it was found that
the sex
ratio of 54(79%) heifer
calves and 14 (21%) bull
calves was statistically
significant at a
probability of p<0.01.
This means that we
accept the hypothesis,
with at least 99%
certainty, that the
shift in sex ratio was
due to
HeiferPlusTM treatment
of the bull semen. The
overall sex ratio of
54/68 (79%) female was a
31% shift from the
normal.
All producers reported
normal pregnancy rates.
A first service
conception rate of 14/16
(87.5%) was observed
during
Trial 2. 9/11(82%) first
service conception rate
was reported in Trial 5.
In these two trials, the
combined 1st service
conception rate was
23/27(85%).
Conclusion:
These trials were done
to test HeiferPlusTM on
working dairy farms
using normal breeding
practices.
HeiferPlusTM treatment
of semen did shift the
female sex ratio by an
observed 31%. Of 68
calves produced using
HeiferPlusTM treated
semen, 54 (79%) were
female. This was a
significant difference
(p<0.01) from the
expected
number of females.
Conception rates
appeared to be normal
when using HeiferPlusTM. |
