Our water buffalo (Bubalus bubalis) has much potential for production of milk. But this
animal has some problems regarding reproduction including delayed puberty, poor estrus behavior,
silent heat, long postpartum period and low conception rate by artificial insemination. This leads
to poor reproduction and hence great economic loss. Therefore, the requirement is to address these
problems efficiently and formulate more effective techniques for improvements. Researchers have
devised many estrus synchronization protocols (PGF2α, P4, GnRH, eCG, hCG etc.) that help
bringing many animals in heat and hence improve the reproductive performance when fixed time
artificial insemination is combined with them. But these protocols give inconsistent results when
they are applied on buffaloes making it necessary to improve the techniques.
This study was planned on the hypothesis that presence of bull (bio-stimulation), at the
time of synchronization, may play an important role in enhancement of estrus intensity and fertility
rate in Nili-Ravi buffaloes. Seventy one adult buffaloes were randomly selected from different
areas of field conditions and LRS (NARC) and subjected to CIDR based heat synchronization in
combination of either bio-stimulation or non-stimulation. The animals were observed for
behavioral estrus signs twice a day starting after 12 hours of CIDR removal till 96 hours.
Pregnancy diagnosis was done by rectal palpation 60 days post CIDR removal. Estrus response
and pregnancy rate were analyzed by Chi-square test using MINITAB version 15. Estrus signs and
total estrus intensity were compared by Mann Whitney U test. Difference was considered
significant at probability level of (P < 0.05).
In peri-urban areas, more animals from bio-stimulated group showed better behavioral
estrus signs, more total intensity score and significantly higher pregnancy rate as compared to nonSUMMARY
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stimulated group of animals. At LRS (NARC), more animals from non-stimulated group were
found in behavioral estrus but intensity of heat signs was high in bio-stimulated animals.
Pregnancy rate was also higher in non-stimulated animals but the difference was not significant.
Overall, in this study, we got higher pregnancy rate in bio-stimulated animals than non-stimulated
group which indicates a positive response of bull stimulation on reproductive performance of Nili-
Ravi buffaloes who were synchronized with CIDR based estrus synchronization protocol.