Luteinizing hormone (LH) profiles after either porcine LH or GnRH treatment in Holstein cows with or without FSH-stimulation Abstract #: 1455 Poster #: W215
1Department
of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada 2Alberta Agriculture and Rural Development, Livestock Research Branch, Edmonton, AB, Canada e-mail:
[email protected];
[email protected]
Background
Methodology & Results
with
25
mg
porcine
luteinizing
hormone (pLH) in “Ovsynch” protocol:
1) Increased pregnancy rate in dairy
Least-square means for plasma LH concentrations
No FSH stimulation (NS; n=13, 0 mg FSH)
0
PGF2α
9
7 9
Sequential blood samples up to 20 h after treatments
expression
of
2
9
1.5
6
1
3
0.5
0
0 0
1
2
3
4
5
Partial stimulation (PS; n=8, 200 mg FSH)
improved oocyte competence [2].
responses and embryo yield in FSH-
100 µg GnRH. 8 69
10 811 121013 141215 161417 181619 2018
20
Partial stimulation
200 mg FSH in 8 decreasing doses
0
5 Sequential blood samples
4 5
PRID
PRID
0–5h
7
up to 20 h after treatments
5 – 20 h
2.5
6
GnRH
The wide variability in superovulatory
for a longer period than in cows given
6 47
intra-
follicular proteins associated with
given 25 mg pLH remained elevated
pLH (n=7)
Time interval (hour)
pLH
cows will reduce variability in ovarian
GnRH (n=4)
response and improve embryo quality
P ≤ 0.05
1.5
4 3
1
remains to be seen.
2 0.5
1 0
stimulated cows might be potentially
-1
0 0
1
2
3
4
5
6 47
8 69
10 811 121013 141215 161417 181619 2018
20
Time interval (hour)
profile cows
attained could
in
be
non-stimulated established
in
superovulated cows.
Full stimulation (FS; n=12, 400 mg FSH)
0
5 PRID
Objective
Sequential blood samples
PRID
up to 20 h after treatments
pLH
Radioimmunoassay: by using an anti-bovine LH monoclonal antibody
LH: Luteinizing hormone
GnRH (n=6)
PGF2α: Prostaglandin F2α
pLH (n=6)
2
P ≤ 0.05
12
5
4
GnRH: Gonadotropin releasing hormone 5 – 20 h
2.5
15
GnRH 400 mg FSH in 8 decreasing doses
0–5h
18
pLH: Porcine luteinizing hormone
1.5
9
PRID: Progesterone-releasing intravaginal device 1
6
Acknowledgment
0.5
3 0 -1
0 0
1
2
3
4
5
64 7
86 9
108 11 121013 141215 161417 181619 2018
20
Time interval (hour)
To characterize LH profiles after giving
Plasma LH remained elevated from 0.5 h to 4 h after GnRH treatment (P ≤ 0.01)
pLH or GnRH in non-lactating Holstein
returning to baseline (≤ 0.5 ng/mL) by 8 h after treatment in all three groups.
cows subjected to different levels of FSH stimulation.
Abbreviations FSH: Follicle stimulating hormone
Full stimulation
LH (ng/mL)
reduced using pLH if the altered LH
Whether giving pLH to superovulated
pLH (n=4)
2
5
LH (ng/mL)
the
GnRH (n=6)
P ≤ 0.05
-1
2) Altered
5 – 20 h
2.5
12
pLH
cattle [1].
0–5h
15
GnRH GnRH
Plasma LH concentrations in cows
No FSH stimulation
LH (ng/mL)
Replacing the second GnRH injection
Conclusion
Plasma LH peaked at 1.5 h and remained above basal concentrations (P < 0.0001) up to 20 h after treatment in pLH-treated NS and FS cows. In pLH-treated PS cows, LH concentrations peaked at 3 h and only remained above baseline for to 10 h post-treatment (P < 0.01).
Research supported by Dairy Research and Technology Centre Ignition Fund, Alberta Agriculture and Rural Development and Alberta Milk. Product donations by Bioniche Animal Health and Vetoquinol are gratefully acknowledged.
References [1]. Colazo et al., 2009; Theriogenology 72:262-270
[2]. Behrouzi, 2014; MSc thesis University of Alberta
