Data from 34 yearling Hereford or Angus bulls were used to investigate relationships of testicular size, quantitative rates of sperm production, Sertoli cell numbers, numbers of germ cells supported per Sertoli cell, and the efficiency of spermatogenesis to daily sperm output and seminal quality. Two ejaculates were collected by electroejaculation from each bull on each of 2 days/week throughout the study. The percentage of progressively motile sperm and the percentage of morphologically normal sperm were determined from aliquots of fresh semen. Additional aliquots of semen were frozen in glass ampules or plastic straws and subsequently evaluated for postthaw motility and percentage of sperm with intact acrosomes. Sertoli cell numbers, the numbers of germcells per Sertoli cell, and the efficiency of spermatogenesis were unrelated to the quality of fresh or frozen semen (P greater than 0.05). In first ejaculates, the numbers of sperm and motile sperm were related (P less than 0.05) to testicular parenchymal weight (r = 0.38, and 0.50), daily sperm production (r = 0.45 and 0.53), and spermatids per gram of testicular parenchyma (r = 0.35 and 0.34). Testicular parenchymal weight and daily sperm production also were related to daily sperm output and to the average daily motile sperm output of these bulls (P less than 0.05), but could account for less than 25% of the variability in these end points among bulls.

The present study was designed to evaluate the longevity of canine cauda epididymal sperm in vitro at 40C. The testes were collected from 30 mixed breed dogs of average weight of 20-25Kg,presented to the clinics for sterilization. The testes were stored at 40C in normal saline in a refrigerator.The sperms were collected from the epididymis at different intervals of time (0, 4, 8, 12 and 24 hr) by taking 6 testes in each interval of time. The sperm quality was accessed at different intervals of time.The data analysed was analysed by ANOVA and the significant level was 5% (P= 0.05). The sperm concentration at different interval of time and storage at 40C did not show significant difference. On the other hand the sperm motility revealed significant difference between all the time intervals of sperm collection except at 8 and 12 hr of collection. There was significant difference of live sperm (%) at different intervals of sperm collection except at 8-12 hrs of sperm collection. The percentage of normal sperms was significantly different in between 0 to 24 hr interval of time but there was no significant difference either at 4 and 8hr or 12 and 24 hr of sperm collection. The acrosomal integrity was found statistically significant between 0-24 hrs of sperm collection and storage at 40C. There was significant difference in percentage of hypo- osmotic swelling between 0 hr (66.67 ± 2.11%), 4 hr (40.50 ± 6.21%), 8 hr (26.27 ± 2.25), 12 hr (11.50 ± 1.38%) and 24 hr (6.67 ± 1.05%). However, there was no difference between 8 and 12 hr of sperm collection from testes and storage at 40 C. The study concluded that the cauda epididdymal spermatozoa can be effectively stored and utilised for the purpose of assisted reproductive technology during emergency. These findings can be applied to the endangered wild canines and felines.

The effects of melatonin and Light treatments on the reproductive performance of yearling Suffolk rams were investigated. The two groups (A, n = 8; B, n = 8) were given a priming period of long days (18 h Light (L): 6 h dark (D) during 1st February to 14th March. During 14th March to 9th September, group A was exposed to local light + melatonin Implants (Regulin) at 5 weekly intervals, group B was exposed to local light + melatonin Fed (M- 5250) alongwith the feed. The group (C, n = 8) in the local light during 1st February to 14th March and during 14th March to 9th September remained on local light + melatonin implants (Regulin) at 5-weekly intervals. However, the group (D, n=8) was treated as control and kept on local light environment (Lat. 51 degree 43'N) throughout the experiment. Testis diameter, sexual behaviours and semen quality were used to assess reproductive performances. The treatment to group A & B resulted in a significant advancement in high reproductive performance. The treatment to group C indicated that the abrupt application of melatonin in mid March resulted in a weak response in terms of all the criteria of assessment. The investigation indicated that seasonal fluctuations in reproductive behaviour and semen quality may be rephrased by the application of light and melatonin treatments and that these treatments may be considered for the preparation of rams for out of season breeding.

This study was carried out to evaluate the possibility of sex preselection by gradients methods using bovine serum albumin in rabbits. Artifical insemination was performed with sperm from the top and bottom layer of rabbit semen separated by bovine serum albumin gradients. Various characteristics of separated sperm, and the conception rate secondary sex ratio at artificial insemination with separated sperm were compared. The sperm from the bottom layer showed significantly high value in motility, percent of normal sperm and progressive motility as compared with control sperm and the sperm from the top layer. The conception rate of sperm from the bottom layer was higher than that of the top layer. But secondary sex ratio was not altered by this methods

As a fundamental study to increase the reproductive efficiency in cattle, highly motile sperm were separated and collected from raw semen, extended semen and frozen semen by different methods using various concentrations of bovine serum albumin or Tyrode's solution. Various characteristics and light microscopic and electron microscopic morphology of sperm separated by different methods were compared