Metabolites and hormones as indicators of postpartum reproductive efficiency of pasture based Friesian dairy cows in Kari-Lanet, Kenya
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Date
2014-11-28
Authors
Indetie, Annah Hoka
Journal Title
Journal ISSN
Volume Title
Publisher
Kenyatta University
Abstract
Agricultural production remains the main source of livelihood for rural communities in sub-
Saharan Africa, providing employment to more than 60% of the population and contributes
about 30% of domestic products. There is a deficit of up to 15 mg /day of metabolisable
energy and effective rumen degradable protein of 235g1 day to support desired levels of milk
output. This deficit has led to low milk 'production and inefficient reproductive performance
of smallholder daily cows. In other parts of the world, influences of Hormones and
.metabolites ..on..Iepr.oducti¥€ .perfcrmance .of.daiJ¥ .cattle hase.been .established, In K€ll¥a,
information on whether metabolites and hormonal levels are indicators of nutritional levels
and reproductive performance of postpartum daily cows is not sufficient. Therefore this study
seeks to determine indicators of postpartum ovarian cyclicity in Friesian daily cows. The
study will be conducted at KARJ- Lanet within the Rift Valley. Purposive sampling technique
will be used to select 30 Friesian cows of parities 1-4 and of body condition score 2-4. The
cows will be grazed on Elba Rhodes. Test group cows (20 cows) will be supplemented with
2kg of total mixed ration (TMR) of Bracharia and Dolichos lab lab pre and 4kg of TMR
postpartum whereas control group cows (10 cows) will not be supplemented. Water and
minerals will be given adlibitum to all cows. Daily milk will be recorded. Cows' weights and
•a0dy ,c0nGi~i0n' -seore -will• •re •r-eo0f€led• weekly. •Cal,ving •a0Gy -ceadition will ore recorded.
Reproductive data will include days from calving to first observed estrus, days to first
service, and conception at first service, and number of services to conception. Blood samples
will be aseptically collected into heparinised tubes twice a week from each cow via jugular
vein into well labeled tubes and will be centrifuged for 15 minutes at l500xg to give plasma
for blood metabolites and hormone analysis. Non-esterified fatty acids, Insulin-like-growth
factor-I, will be measured using commercial kits. Twenty milliliters (mls) of evening milk
will aseptically be collected into 25mls sample bottles containing sodium azide as a
preservative. The milk will be centrifuged at 300 revolutions per minute for 30 minutes and
the resulting skimmed milk used for progesterone analysis using lAEAIF AO bench protocal.
Plasma Leptin concentration will be determined every 4 days using established methods.
Pasture ana .f0tal••mi*ea •rati0B feede -ana-lysi•g -will •ae -done •using wet •chel'Il:-istry to •give
chemical composition of the feeds. Milk production, BCS, metabolites and hormonal
concentrations will be analysed by mixed procedure (SAS institute Inc. Cary, NC. USA).
Turkey Kramer tests will be conducted to analyse differences within and across treatments.
Factors affecting the initiation of ovarian cyclicity will be evaluated by regression analysis using
backward elimination procedure. The independent variable will be the re-initiation of ovarian
cyclicity and the dependent variables will include parity, BCS at parturition, body weight, milk
production, total protein, urea, NEFA, IGF-l and leptin. The recommendations of this study
could put interventions in place for reproductive efficiency leading to increased milk and meat