This study was conducted to evaluate the effect of bub aline follicular fluid (FF) on aero somal integrity of buffalo spermatozoa. Steroid free and whole FF from buffalo ovaries at the concentration of I % alone and in combination with cysteine HCI (0.1 %) and EDT A (0.1 %) were used as additive in tris dilutor for preservation of washed and unwashed buffalo spermatozoa at 4°C and -196°C. The intact acrosome and abnormal acrosome at different stages of preservation were assessed. The effect of FF on acrosome was significant (P<0.01), and inclusion of FF as additive in tris dilutor exerted a protective effect on the acrosome during refrigerated preservation and freezing. This is an indicative of some synergistic action of FF along with other cryoprotectants in the dilutor.

Study was conducted on progesterone profile, estrus response and fertility using norgestomet regime alone and alongwith PMSF and PGF 2 α in 28 anestrus cattle. Estrus resptonse, anset of estrous interval and fertility at induced estrus following withdrawal of implant was better in norgestomet+PMSG treated group (71.42%, 52.8 hr; 60%)than norgestomet alone (71.42%; 62.4 hr; 40%)and norgestomet+PGF 2 α+PMSG (57.14%; 55.5 hr; 50.0%). The duration of estrus (19.0-18.8 hr) did not differ significantly among the treatment groups and control. Overall AI per conception and resumption of fertility were also higher in norgestomet+PMSG treated than in the other groups. The progesterone profile prior to insertion of implant fluctuated at the bases level (0.496-0.630 ng/ml) confirming the true anestrus state in the animals. Progesterone profile following onset of estrus after withdrawal of norgestomet implant increased significantly in all the treated group (2.16-2.62 ng/ml) indicating development of corpus luteum and efficacy of norgestomet implant in inducing ovulatory estrus.

Forty-eight ejaculates (24 each from FH and FJH crossbred bulls) were subjected to freezing and hypo-osmotic swelling rest to record freezability in relation to membrane integrity of the spematozoa. In fresh semen no significant difference between HOS-positive spematozoa of bath the crosses was found but hull variation was significant. HOS-positive sperm after freeze thawing also did not differ significantly between both the crosses, however, in FH crosses, a significant bull to bull variation was recorded. After freeze thawing the number of HOS-positive spermatozoa decreased to 30-50% and almost all the types of HOS-positive sperms were recorded. A significant positive correlation of BOS-positive sperm with mass motility, initial progressive motility, live count total intact acrosome and sperm concentration was also found.

Effect of 3 buffers (TRIS, MES and TRICINE) and chlorpromazine NCI as an additive on the freezability of halfbred (HFxH) bull spermatozoa using 48 ejaculates (12 each from 4 bulls) were studied. Motility, livability and enzymes (GOT, GPT, ACP and AKP) were estimated in fresh, prefreeze and post-thaw semen. A significant (P<0.01) variation in motility and livability due to dilutors at prefreeze and post-thaw revealed TRIS as superior buffer than MES and TRICINE. The minimum leakage of enzyme was found in TRIS with chlorpromazine and maximum in TRICINE in absence of chlorpromazine. A significant (P<0.01) improvement in seminal cytomorphological characters and low leakage of spermatozoal enzyme revealed, incorporation of chlorpromazine to be beneficial in achieving better post-thaw recovery rate.

A simple and easy modified method for conducting in vitro cervical mucus penetration test used for quality assessment of fresh and frozen-thawed spermatozoa of crossbred bulls is described. The triple crossbred bull semen had significantly lower volume but higher sperm concentration and abnormal sperms than the halfbred bulls. Sperm penetration distance (SPD) travelled by HFH and FJH was 34.71+/-2.51 and 29.92+/-2.72 mm of fresh semen and 13.14+/-2.16 and 10.64+/-1.92/mm of frozen semen in 60 min. SPD travelled by vanguard spermatozoa differed significantly (P<0.01) among the bulls and between the crosses. SPD travelled by fresh spermatozoa was significantly and positively correlated with mass motility, individual motility, live sperm, per cent intact acrosome and SPD of post-thawed semen. Post-thaw SPD did not differ between both the crosses. SPD differed significantly (P<0.01) between dilutors and was higher in tris than that of MES. Addition of raffinose in the dilutor did not affect the SPD of post-thawed spermatozoa. The study indicated that initial motility had a bearing on SPD in cervical mucus and this can be used as a tool for assessment of post-thawed semen.

Study was carried out on 184 cows and 142 buffaloes of village, to know the relationship between time of insemination and conception. These animals had apparently clear oestrual discharge at the time of artificial insemination. Cows inseminated at 0-6 and 31-48 hr interval of oestrus symptoms, did not conceive. Cows which were inseminated at 11-14 hr interval had maximum conception rate (53.72%) followed by (47.05%) insemination at 7-10 hr. Conception rate decreased subsequently in cows which were inseminated after 14 hr of oestrus symptoms.In contrast to cows, conception rate was maximum (50.00%) in buffaloes after insemination at 23-26 hr interval of oestrus symptoms. Conception rate was also 40.00% after insemination at 19-22 hr. No conception occurred when buffaloes were inseminated up to 10 hr of oestrus symptoms. This study reveals that in comparison to cows. higher conception in buffaloes is achieved after insemination at later stage which may be due to their nature of delayed ovulation.

Post-thaw motility (PTM) and post-thaw aging motility (PTAM) were significantly (P < 0.01) higher in tris containing glycerol than that without glycerol, almost with all the sugars. In the absence of glycerol post-thaw incubation motility (PTIM) and PTAM did not differ from each other due to different sugars. But in presence of glycerol PTM and PTIM were significantly (P < 0.01) higher with raffinose than that with other sugars. Higher number of sperm survived freezing stress in presence of glycerol and per cent live sperm differed significantly (P < 0.05) due to different sugars. Glycerol and sugars combinedly exerted beneficial effect on acrosomal maintenance also. Higher number of per cent normal acrosome was recorded in presence of glycerol and sugars except 2.0% sucrose and 2.0% table sugar (the higher molecular weight sugars).

A factorial experiment was conducted to determine the relative efficacy of 2 diluents (Tris and milk), 4 cooling rates (1030 °C to 5 °C; 1 and 2 h each), 2 equilibration periods at 5 °C (0 and 2 h), 3 thawing rates (4 °C/5 min, 40 °C/1 min and 60 °C/15 sec), and their interactions in the cryopreservation of Murrah buffalo (n = 3) semen on the basis of pre- and post-freezing motility, and post-thaw incubation (0, 30, and 60 min at 37 °C) and aging (6, 24 and 48 h at 5 °C) motility, and fertility to first AI (806). The pre-freeze sperm motility was significantly lower (P < 0.05) following 1 and 2 h of direct cooling from 10 to 5 °C (65 and 70%) than the corresponding values of routine cooling from 30 to 5 °C (72 and 76%). Post-thaw forwardly motile spermatozoa at all intervals of incubation or aging including conception rates (65.4 and 68.1%; 90-d palpation confirmation) were significantly (P < 0.01) higher following 2 h of prefreeze cooling both from 10 and 30 °C compared with l h of cooling from the respective temperatures (59.5 and 63.4%). Further, 2 h of equilibration at 5 °C compared with 0 h significantly improved the post-thaw recovery (48 vs 39%), incubation/aging survival (8 to 12%) and fertility rates (71 vs 56.5%) of frozen semen. Post-thaw recovery and incubation/aging survival of buffalo spermatozoa also increased significantly with each increment in thawing temperature from 4 to 40 to 60 °C. There were positive correlations between post-thaw motility and longevity of spermatozoa, and fertility. Overall, both Tris- and milk-based diluents were equally efficacious; slow cooling of straws from 30 to 5 °C for 2 h compared with faster cooling (1 h) or lower initial temperature (10 °C) and 2 h of equilibration at 5 °C appeared inevitable for successful cryopreservation of buffalo semen. A thaw rate of 60 °C/15 sec yielded better post-thaw recovery and longevity and could improve fertility of buffalo spermatozoa.