The reproductive disorders are the major causes of reproductive infertility in cows that affect the total annual calf crop, resulting in great economic loss in Bangladesh. The aim of the study was to find out the reproductive disorders (RD) in dairy cows that markedly influences the reproductive performances in aspect of Bangladesh. A total number of 1658 dairy cows were selected according to their body condition score (BCS) in different farms at the southern part of Bangladesh during the period of 2011 to 2012. The preliminary data (basic information) were collected directly from the dairy farmer’s record books and asking questions according to a prescribed questionnaires as well as the diagnosis of RD was presumptively confirmed on the basis of history, clinical signs and examination of animals by ultrasonography and others necessary tools. There are thirteen major reproductive disorders were identified. Overall prevalence of reproductive disorders at that area were 23%, among of these anoestrus 5.1%, repeat breeder 3.7%, metritis 4.4%, poor heat detection 1.6%, ovarian cyst 0.36%, retain placenta 4.6%, dystocia 0.97% and pyometra 0.24%. It is indicated that anoestrus and retention of placenta after calving was most hazardous cause of infertility whereas the metritis and repeat breeder were the second line of consequence. RD had shown significantly higher incidence in low BCS (≤2) than that of fair (2.5) and very good (≥3∼3.5). In conclusion, the highest RD especially anoestrus and retention of placenta is very alarming for reproductive loss which might be needed further research to identify the specific cause of these disorders for establishment a profitable dairying and dairy population.

In vitro maturation and activation of oocytes are primary steps towards biotechnological manipulation in embryology. The objectives of the present study were to determine the oocyte recovery rate per ovary, in vitro maturation rates of oocytes and rates of parthenogenetically activation of matured oocytes in Black Bengal goats. All visible follicles were aspirated to recover follicular fluid from individual ovaries (number of ovaries = 456). The immature cumulus oocyte complexes (COCs; n = 1289) were cultured in tissue culture medium (TCM)-199 supplemented with 10% (v/v) fetal bovine serum (FBS) for 27 hours at with 5% in humidified air. The matured oocytes (n = 248) were activated with 5 ionomycin for 5 minutes followed by treatment with 2 mM 6-dimethylaminopurine (6-DMAP) for 4 hours. After activation, oocytes were cultured for another 14 hours in TCM-199 supplemented with bovine serum albumin (BSA) at with 5% in humidified air. The pronucleus formation in activated oocytes was determined by staining with 1% orcein (whole mount technique). Matured oocytes (n = 176) without activation stimuli were used as control. The mean number of oocytes recovered per ovary was . The proportion of oocytes matured in vitro, confirmed by the presence of first polar body, was . Parthenogenetic activation, evidenced by formation of pronucleus, occurred in of matured oocytes. No pronucleus formation was observed in control oocytes. In conclusion, a combination of ionomycin and 6-DMAP induces activation in one third of Black Bengal goats' oocytes.

Ovulation synchronization (ovsynch) has proved to increase the number of insemination in cattle by overcoming the problems of heat detection. The aim of this study was to do ovsynch in water buffaloes where heat detection is a major reproductive problem and to determine the conception rates after timed artificial insemination (TAI). Twenty cyclic buffaloes at 60 days postpartum were selected by examining 24 unobserved estrus buffaloes based on milk progesterone assay (progesterone concentration 1.0 ng/ml) from the Mymensingh district of Bangladesh. Ovsynch treatment regimen was started irrespective of the stage of estrous cycle. Gonadorelin (500 ) was injected intramuscularly at Day 0 followed by Alfaprostol (8 mg) at Day 7. A second injection of Gonadorelin was given at Day 9 and TAI was done with frozen semen from Mediterranean buffalo bulls at 16~20 hours of the second Gonadorelin injection. Milk progesterone ELISA at Day 10~12 post AI confirmed ovulation in 16 out of 20 (80%) buffaloes (progesterone concentration 1.0 ng/ml). High progesterone concentration ( 1.0 ng/ml) at Day 10~12 and Day 22~24 of AI showed pregnancy in six out of 20 (30%) buffaloes. Pregnancy was further confirmed by ultrasonography at Day 40 in these six buffaloes. In conclusion, ovsynch followed by TAI could be applied in cyclic buffaloes for overcoming the estrus detection problems; however, more studies are needed to increase the conception rate.

Only an optimum number of viable spermatozoa in a frozen-thawed insemination dose can ensure conception at artificial insemination (AI). We report here the percentages of normal, abnormal and viable spermatozoa present in the frozen-thawed semen of 20 Black Bengal bucks used for commercial AI. Bucks in this experiment were of 19.3~46.1 months old and 25~42 kg body weight. Four semen straws (0.25 ml) from each buck were collected for evaluation of their kinetic parameters. Scrotal circumference was measured by using a scrotal tape, sperm motility was estimated on eye estimation and sperm concentration was determined by using a haemocytometer. Sperm morphology was studied in paraformaldehyde fixed spermatozoa under differential interference contrast (DIC) microscope. To determine the proportion of live (plasma membrane intact) spermatozoa, semen was stained with SYBR-14 and propidium iodide and examined under fluorescent microscope. Scrotal circumference, post-thaw sperm motility, sperm concentration per insemination dose and proportion of normal spermatozoa were , , million and , respectively. The percentages of spermatozoa with head shape and acrosome abnormalities were lower ( and , respectively), whereas higher percentages of abnormalities () were observed in mid piece and tail portion. The proportion of live spermatozoa was . It is concluded that although a good number of morphologically normal spermatozoa are present in the insemination dose, the proportion of live spermatozoa is low, which warrants further improvements of buck semen freezing procedures to ensure good quality at AI.

Successful in vitro embryo production heavily relies on the normal maturation and fertilisation of oocytes. We examined the normal and abnormal fertilisation of zebu cattle oocytes matured in vitro. Immature cumulus oocyte complexes (COCs) from zebu cattle ovaries at slaughter were matured in vitro (IVM) for 24 h. The oocytes were either fixed, stained and examined for nuclear changes or fertilised in vitro (IVF) with Percoll-separated, heparintreated spermatozoa (1.0 /mL) of zebu (n = 7) and crossbred bulls (n = 7). After 18 h of sperm-COCs co-incubation at C with 5% in humidified air, the presumptive zygotes were fixed, stained and examined for pronuclei. The number of oocytes retrieved per ovary was 5.4 0.7. The percentage of matured oocytes was 73.0. The difference in motility of spermatozoa before and after Percoll seperation was significant (p<0.001). The percentages of normal and abnormal fertilisation (polyspermia and oocytes with one pronucleus) varied significantly depending on individual bulls (p<0.05). A protocol for IVF of IVM oocytes in Bangladeshi zebu cattle is developed. A future study may elucidate the capacity of such IVM-IVF oocytes to develop to the blastocyst stage for transfer to surrogate mother.