Abstract:
The study was conducted to assess early-expressed
reproductive traits of Boran cattle and their crosses with Jersey
and Holstein Friesian (HF). The traits studied were age at first
services (AFS), number of services for first conception, age at
first calving (AFC), first dry period (FDP), first calving interval (FCI), and first service period (FSP). Genetic group and
period of birth/calving had a significant (p <0.05) effect on
reproductive traits. The Boran cattle were inferior to HF or
Jersey crosses. First crosses (F1) for Jersey and Boran (50 %
Jersey: 50 % Boran) showed a significantly (p <0.05) younger
AFS (by 7.25 months) and AFC (by 10.75 months), had
shorter FCI (by 63.27 days), FDP (by 61.13 days), and FSP
(by 60.3 days), and needed less (by 0.35) numbers of services
per first conception as compared to the Boran cattle. The F1
for Jersey and Boran (50 % Jersey: 50 % Boran) crosses
showed better performance than the F1 for HF and Boran
(50 % HF: 50 % Boran). Heritability values for AFS and AFC
were the highest and were estimated at 0.51±0.10 and 0.49±
0.13, respectively, and lowest heritability was recorded for
FDP (0.02±020) and FSP (0.10±0.29). The genetic correlation was highest (0.10±0.20) between AFS and AFC and was
lowest (−0.01±0.66) between FCI and FSP. The breed additive for Jersey was only significant (p <0.01) for AFS and
AFC. The crossing of HF with Boran cattle has desirably
reduced 9.16±2.88 months in AFS; the corresponding reduction in AFS was 3.49±3.59 months by crossing with Jersey.
The performance comparisons and genetic and crossbreeding
parameters indicated that crossbreeding of Boran with HF or
Jersey can improve reproductive performance.
