Zahid Naseer

Fertility following CIDR based synchronization regimens in anoestrous Nili-Ravi buffaloes.

The objective of this study was to compare oestrus expression and fertility rate in used and new controlled internal drug releasing (CIDR) device treated anoestrous buffaloes. Furthermore, to determine the timing of ovulation, and fertility rate in estradiol benzoate (EB) and GnRH-administered CIDR-treated anoestrous Nili-Ravi buffaloes. In experiment 1, buffaloes received either a used CIDR (UCIDR, n = 35) or a new CIDR (NCIDR, n = 36) for 7 day and PGF2α on day 6. Oestrous expression was similar (p > 0.05) between UCIDR (88.5%) and NCIDR (96.6%) buffaloes. The pregnancy rate did not differ (p > 0.05) because of treatment (37.1% in UCIDR vs 36.6% in NCIDR). In experiment 2, buffaloes (n = 55) received CIDR device for 7 days and PGF2α, on day 6 and randomly assigned into three treatment groups: (i) CIDR-EB (n = 17) received EB on day 8, (ii) CIDR-GnRH (n = 18) received GnRH on day 9 and (iii) control (n = 20) received no further treatment. Mean interval from CIDR removal to ovulation in CIDR-EB, CIDR-GnRH and CIDR group were 61.3 ± 0.8, 64.9 ± 1.8 and 65.1 ± 16.7 h, respectively. However, the buffaloes in the CIDR-EB and CIDR-GnRH group had lesser variability in the timing of ovulation compared to control. The pregnancy rate of both CIDR-EB group (58%) and CIDR-GnRH group (61%) were tended to be higher (p < 0.1) than control (30%). In conclusion, compared to NCIDR devices, previously UCIDR devices are equally effective to induce oestrus in anoestrous buffaloes resulting optimal pregnancy rate. Administration of EB and GnRH after CIDR removal results in tighter synchrony (less variability) and improved fertility in anoestrous buffaloes. CIDR based synchronization regimens have great potential in fertility improvement in anoestrous buffaloes.

Protective effect of cholesterol-loaded cyclodextrin pretreatment against hydrogen peroxide induced oxidative damage in ram sperm

Three experiments were conducted to determine the protective effect of cholesterol-loaded cyclodextrin (CLC) against hydrogen peroxide (H2O2) or cryo-induced damage in ram sperm. In Experiment 1, the fresh ejaculates were either treated with CLC or remained untreated. Both CLC treated and untreated samples were then incubated with 0, 250 or 500 μM H2O2 at 35°C for 12 h. After incubation period of 12 h, the motility, viability and membrane integrity remained higher in CLC treated sperm even in the presence of 250 or 500 μM H2O2. The H2O2 treatment affected all the sperm parameters adversely (P<0.05). However, compared to CLC untreated counterpart, the motility, viability and membrane integrity remained higher (P<0.05) in treated sperm, even in the presence of 250 or 500 μM H2O2 during 12 h of incubation. In Experiment 2, semen was cryopreserved in the presence or absence of CLC. The post-thaw results revealed that CLC treated sperm has higher (P<0.05) motility, viability and membrane integrity compared to the control. In Experiment 3, lipid peroxidation levels were assessed by determining malondialdehyde (MDA) concentrations during the H2O2-induced oxidative stress in CLC treated and untreated sperm. However, no difference (P>0.05) in MDA level was observed among the groups at any stage of incubation. In conclusion, the CLC incorporation in ram sperm membrane may protects it against H2O2 or cryo-induced oxidative damage. The cryoprotective influence of CLC on ram sperm might be resulted from, at least partly, its antioxidative property.

Comparison of two different cryopreservation protocols for freezing goat semen.

In this study, two different semen cryopreservation protocols were compared to freeze goat semen. The ejaculates (n=12) were collected by using electro-ejaculator from six mature bucks (two ejaculates per each buck). Each ejaculate was divided into two groups as Protocol 1 (P1) and Protocol 2 (P2). In P1, semen was diluted directly in an extender containing 15% egg yolk, 300mM Tris, 28mM glucose, 95mM citric acid 5% glycerol to a concentration of 200×10(6)sperm/mL. In P2, after the removal of seminal plasma by centrifugation, the semen sample was diluted with the first portion of milk extender consist of 100mg/mL skimmed milk powder and 27.75mM glucose (without glycerol) to a concentration of 400×10(6)sperm/mL. The second portion of the milk extender containing 14% glycerol was added to semen gradually in order to achieve sperm concentration 200×10(6)sperm/mL and 7% glycerol level in the final volume. Extended semen was loaded in 0.25mL straws, held for 2h at 4°C, frozen in nitrogen vapor and stored in liquid nitrogen. Post-thaw motility and live sperm rate (mean±SEM) were significantly lower (P<0.05) in P1 as compared to P2 (47.50±1.23% vs. 55.63±1.72%; 80.04±1.29% vs. 84.04±1.08%, respectively). However, live intact, total intact, abnormal, reacted acrosome and DNA damaged sperm rates were similar (P>0.05) in both protocols. It was concluded that both protocols used in this study provided reasonable post-thaw parameters; however, P2 yielded better motility and live sperm rate compared to P1.

Treatment of anestrous Nili-Ravi buffaloes using eCG and CIDR protocols

Abstract Objective To determine the effect of equine chorionic gonadotropin (eCG) and controlled internal drug releasing (CIDR) on estrus response, ovulation and pregnancy rate in Nili–Ravi buffaloes under field condition. Methods Twenty anestrous buffaloes with more than 150 days postpartum were used in this study. To confirm anestrous condition, ovarian status and serum progesterone concentration were determined before the start of study. Buffaloes were randomly divided into eCG (n=10) and CIDR (n=10) groups. eCG group were treated with eCG (Chronogest 1000 I.U. i.m.), while CIDR group received CIDR devices for 7 days. All buffaloes in CIDR group were injected PGF2 α (0.25 ug/mL; 2 mL; i.m.) one day before CIDR removal. Buffaloes were observed for estrus visually and were inseminated with frozen-thawed semen at detected estrus. Ovulation was confirmed by presence of CL 12 day post AI. Pregnancy diagnosis was done 50 days post AI. Results Estrus response, ovulation rate and pregnancy rate were similar (P>0.05) among eCG and CIDR groups (90% vs. 80%; 78% vs. 75% and 50% vs. 60% respectively). Conclusion It is concluded that both CIDR and eCG protocols are effective and promising remedies for the anestrous buffaloes under commercial as well as under field conditions.

Dietary quercetin maintains the semen quality in rabbits under summer heat stress

This study focused to determine beneficial impact of feeding quercetin supplemented diet on semen quality in summer heat imposed rabbits. Twelve heat stressed (HS) adult rabbits bucks were either fed with basal diet (HS; n = 06) or quercetin supplemented diet (QU-HS; n = 06) for a period of 56 days. Semen samples were collected and evaluated for volume, osmolality, morphology, concentration, motility, motion kinetics, viability, acrosome integrity, mitochondrial potential, and seminal plasma MDA level. Semen volume, concentration, motility and sperm kinetics parameters were affected by diet supplementation. Diet affected the sperm mitochondrial potential and day of treatment affected the viable sperm percentage. There was an effect of diet, day of treatment and diet by day interaction on acrosome reaction rate. Sperm head abnormalities were influenced by diet provision, sperm mid-piece abnormalities were affected by diet and day of treatment, whereas, the effect of diet and diet by day of treatment interaction were observed for total sperm abnormalities. There was an effect of diet and diet by day interaction for seminal plasma MDA level. In conclusions, quercetin reduces the damaging effects of HS and maintains the semen quality by lowering the oxidative stress in rabbits.

Seasonal variations in sperm acrosome reaction, osmotic tolerance and serum testosterone concentrations in rams

The study was conducted to evaluate the seasonal dynamics in the sperm acrosome reaction (AR), osmotic tolerance and serum testosterone concentration in rams. Blood and semen samples were collected from six mature rams during the winter, spring, summer and autumn seasons. The AR in sperm samples was induced by using lysophosphatidylcholine (LPC) and calcium ionophore (CI). The AR was monitored at various incubation times (15, 30, 60, 120 and 180 min) post-induction. To determine the osmotic tolerance through hypo-osmotic swelling test (HOST) the sperm were exposed to different osmotic conditions (50, 100, 290, 500 and 1000 mOsm/L). The serum testosterone concentration was assessed using a solid phase enzyme-linked immunosorbent assay (ELISA). The proportion of acrosome reacted sperm was greater (P <  0.05) during the winter season in the LPC and control groups, whereas, it was greater (P <  0.05) in two different seasons (winter and summer) at all incubation time points (15-180 min) in the CI group. The live HOST +ve, total HOST +ve and total live sperm were least (P <  0.05) during the winter season. The greatest membrane integrity (P <  0.05) was in the autumn season. The peak (P <  0.05) serum testosterone concentration was during the summer season. In conclusion, the osmotic tolerance and sensitivity of ram sperm to undergo the AR in response to LPC and CI vary with season. The increased testosterone concentration in the summer season might be the reason for a greater membrane integrity during the subsequent autumn season in Kivircik ram sperm.