Effect Of Bio-Stimulation On Estrus Expression And Pregnancy Rate In Cidr Based Synchronization Protocol In Nili-Ravi Buffalo
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: 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
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.
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Effect Of EDTA As Chelating Agent In Extender On Post Thaw Quality Of Buffalo Bull Spermatozoa
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: Pakistan is an agricultural country where livestock has main contribution in the agriculture. Livestock fulfils the demands of milk, meat and hides. Nili-Ravi is the most important and well developed breed of buffalo and also the highest milk producer among buffalo breeds. Artificial insemination (AI) is the main genetic improvement tool in domestic animals. Spermatozao is cryopreserved for A.I. but is prone to mechanical and biochemical damages during cryopreservation. Numerous strategies have been implemented to overcome this problem which include supplementation of different additives in semen extender to avoid the damages and improve post thaw quality. One of the reason for poor fertility with cryopreserved semen is early capacitation and acrosome reaction signaled by calcium. Early capacitation and acrosome reaction be suppressed by adding calcium chelators. Therefore, present study was aimed to evaluate the effect of EDTA as a calcium chelator in semen extender. The study was conducted at National Agricultural Research Center, Islamabad. Semen was collected twice in a week from 4 mature semen donor Nili-Ravi buffalo bulls maintained at same management conditions. Total of 4 ejaculates were collected and each ejaculate was further divided into 4 aliquots on the basis of EDTA concentration. Group I (0% EDTA), group II (0.1% EDTA), group III (0.2% EDTA) and group IV (0.3% EDTA). Semen was cryopreserved and on post thaw visual motility, acrosome integrity, plasma membrane integrity and chromatin integrity were assessed. Sperm motility and motion characters were assessed through computer assisted semen analyzer (CASA). Through CASA, total motility %, VSL μm/sec (straight line velocity), VCL μm/sec (curve line velocity), VAP μm/sec (average path velocity), BCF (beat cross frequency), LIN % (linearity) and STR % (staginess) were observed. Observations of CASA was were taken at 2 different time intervals i.e. 30 and 60 minutes after post thaw. Data was analyzed by statistical
software one way ANOVA (MINITAB v 12.22, State College, Pennsylvania, USA) and was presented as (mean ± SEM). Significant level was set to be (p<0.05). Group III improved visual motility, progressive motility %, plasma membrane integrity significantly (p<0.05). Results of BCF, VCL, VSL and VAP were highest in group III which differed with other three groups significantly (p<0.05). 0.3% EDTA deteriorated most of the parameters of semen observed. Control group and 0.1% behaved almost in similar pattern and no significant different was observed between these two groups but they did not improved all the parameters like group III. hence it can be concluded that 0.2% EDTA improves most of the semen parameters observed so it should be included in semen extender to have better post thaw quality of Nili-Ravi buffalo bull semen.
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Effect Of Trehalose And L-Cysteine On Post Thaw Semen Quality, Antioxidant Enzyme Activity And Fertility In Nili Ravi Buffalo Bulls
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: Addition of various antioxidants in semen extender is one of the vital strategies being applied in reproductive biology for attaining functionally/structurally integral sperms and hence an appropriate conception rate. It is well established that chilling of buffalo semen results in decreased semen quality which is highly associated with decreased antioxidant activity and higher ROS production. Furthermore, buffalo bull spermatozoa are more susceptible to oxidative damage as compared to cattle bull spermatozoa. It is believed that this difference is due to higher contents of polyunsaturated phospholipids present in plasma membrane of buffalo bull spermatozoa. Freezing process accelerates the production of ROS molecules which may decrease the viability of buffalo bull spermatozoa during storage. Therefore, supplementation of antioxidants in semen extender is required to decrease the ROS-mediated damages to buffalo spermatozoa. The present study had, hence, been designed to monitor the effects of trehalose and L-Cysteine on the semen quality, antioxidant enzyme activity and fertility of Nili Ravi Buffalo bulls.
Semen samples (n= 20) from 4 buffalo bulls were diluted in Tris-citric acid based extender having different concentrations of trehalose (0.0, 15, 30, 45, and 60 mM) and frozen in French straws. At post dilution, profile of sperm catalase (U/mL) was higher (P < 0.05) in extenders containing 15, 30 and 45 mM of trehalose as compared to control. While profiles of superoxide dismutase (U/mL) and total glutathione (μM) were higher (P < 0.05) in extenders containing 15 and 30 mM of trehalose as compared to control. At pre freezing, sperm catalase, superoxide dismutase and total glutathione profiles were higher (P < 0.05) in all the treatment groups as compared to control. At post thawing, the profiles of catalase and total glutathione
were higher (P < 0.05) in extender containing 30 mM trehalose as compared to other treatment groups and control. Whereas, profile of superoxide dismutase was higher (P < 0.05) in extenders containing 30, 45 and 60 mM of trehalose as compared to control and 15 mM group. Post thaw total sperm motility (%) was higher (P < 0.05) in extender containing 30 mM trehalose as compared to control and 15 and 60 mM groups. While sperm progressive motility (%), rapid velocity (%), average path velocity (μm/s), straight linear velocity (μm/s), curvilinear velocity (μm/s), plasma membrane (structural and functional, %), acrosome (%) and DNA (%) integrity were higher (P < 0.05) in extender containing 30 mM trehalose as compared to other treatment groups and control. The fertility rates (61% vs. 43%) were higher (P < 0.05) in buffaloes inseminated with semen doses cryopreserved in extender containing 30 mM of trehalose than the control. It is concluded that addition of 30 mM trehalose in extender improves the semen antioxidant enzymes activity, post thaw quality, and fertility in Nili Ravi buffaloes.
Similarly Semen samples from 4 buffalo bulls were diluted in Tris-citric acid based extender having different concentrations of L-cysteine (0.0, 0.5, 1.0, 2.0, and 3.0 mM) and frozen into 0.5 ml French straws. The antioxidative enzymes [catalase, super oxide dismutase and total glutathione (peroxidase/reductase)] were significantly higher (P< 0.05) at pre freezing and post thawing in extender containing 2.0 mM L-Cysteine as compared to other groups. Post thaw total motility (%), progressive motility (%), rapid velocity (%), average path velocity(μm s-1), straight line velocity (μm s-1), curvilinear velocity (μm s-1), beat cross frequency (Hz), viable sperm with intact plasmalemma (%), acrosome and DNA integrity (%) were higher with addition of 2.0 mM L-cysteine as compared to other groups (P < 0.05). The fertility rates (59 vs. 43%) were higher (P < 0.05) in buffaloes inseminated with doses containing 2.0 mM of L-cysteine than the control. In conclusion, addition of 2.0 mM L-cysteine in extender improved the
antioxidant enzymes profile, post thaw quality and in vivo fertility of Nili Ravi buffalo bull spermatozoa.
It was concluded that addition of 30mM Trehalose and 2.0mM L-Cysteine in semen extender has significantly improved semen antioxidant enzymes activity, post thaw quality and fertility in Nili Ravi buffaloes.
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