dc.description.abstract |
The study was conducted in Bahir Dar Zuria, Mecha and Yelmana Densa districts from September 20 I 3 to
October 2014, with the objective of assessing breeding practices and evaluating effectiveness of estrus
synchronization techniques in indigenous and crossbred cows in West Gojjam zone. Interviews using pretested
structured questionnaires administered to 180 households and 9focus group discussions were used to
generate the data on dairy cattle breeding practices in the study area. Variables like conception, pregnancy
and estrous response rates were dependent variables. Fixed effects were district, dam breed, body condition,
parity, year, AI technician efficiency and bull id. Data analysis was done using SAS (9. I) and SPSS version
20.Proc freq. of SAS procedure was used to evaluate the reproductive data obtained from mass
synchronization and prostaglandins treatment, one way ANOVA was used for milk production and chisquare
was carried out for comparison of proportions. In the experimental study, from the total of 126
PGF2a (Luialyse") treated dairy cattle (97 of parity 1 to 5 and 29 of heifers) with good body condition 3-7
were injected 5 ml prostaglandin intra muscular. In estrus synchronization and mass artificial insemination
(OSMAI), from the total of screened 225 PGF2a (Estrumate'') treated dairy cattle (/54 of parity I to 5 and
7I of heifers) with body condition 3- 6 were injected 2 ml prostaglandin intra muscular in the same study
area. The most common mating system in all sites was natural control mating. The primary breeding
objective of the community was to obtain better milk yield. Milk (Index= O. 169) was the first production
preference of the respondent farmers in the study area. About 53.54 % of dairy farmers in the study area
preferred AI with synchronization followed by controlled natural mating (30%).For estrus synchronization
study, appropriate animal handling facilities were identified in selected farmers' hand. About 88. 90% and
66. 15% mean estrus response rates were found in experimental study and OSMA I campaign respectively for
all districts. The overall pregnancy rates of dairy cattle in the study area in 2013 and 2014 were 36.27%
and 60.32%, respectively. Both in 2013 and 2014, the effects of districts, age, body condition and parity
were significant (P<0.05) in which conception and pregnancy rates were high in cows from Yelmana Densa
district, cows with age of 4 and 5 years, cows with 4.5 body condition score and cows with parity five. Breed
and Bull ID (2014) were not significant (P>0.05) but the conception and the pregnancy rates had great
difference between OSMAI and experimental study records. Milk progesterone was assayed using
Hormonost'" Micro Lab Farmers Test from day 0 (hormone injection) day 52 post insemination. High
progesterone concentration from day 19'h _28'h was considered as positive, low progesterone concentration
in day 19 was considered as non pregnant. And low progesterone concentration after day 28 and day 42
post Al was considered as pregnancy loss. According to milk progesterone concentration obtained from
Hormonost® Micro Lab Farmers Test, about 25% (5/20) of the cows lost their embryo and fetus. Three cows
were unable to retain their pregnancy. They had not maintain the embryo viable and the embryonic
mortality was occurred on 28'h day post insemination, which is 15 %( 3/20) of the experimental animals.
Despite the other two dams did maintain their embryo until 42 days, unable to retain their fetus after day 42,
which is 10% (2/20) of the experimental animals. From the findings of this study it can be inferred that
prostaglandin was effective to synchronize local and cross cows and heifers in both OSMAI and
experimental study. However, the rate of pregnancy was very low in OSMAI campaign. Therefore, selection
offarmers and cattle for synchronization purpose should be done carefully. Progesterone profile analysis is
very important to detect estrus, pregnancy and embryonic mortality of dairy cattle. Those cows that show
standing estrus should only be inseminated. The maximum expected heat detection date should be extended
to 7 days not to miss delayed estrus. Further study should include different protocols and areas of the
country for cattle. |
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