Objective sperm motion analysis to assess dairy bull fertility using computer-aided system--a review

Motility is one of the most important characteristics associated with the fertilizing ability of spermatozoa and is an expression of their viability and structural integrity. Computer-assisted semen analyser (CASA) provides precise and accurate information on different sperm motion characteristics. This article reviews various aspects of computer-aided motility analysis of bull sperm like sample preparation, standardization of instrument settings, importance of various motility parameters evaluated by the system and its impact on basic functional studies of spermatozoa. It gives special emphasis to various aspects of bull sperm motion analysis especially sub-populations of spermatozoa, hyper-activation, motion characteristic in different genetic and age groups, etc. and their utility in predicting the fertility of dairy bulls. The need to fill the gap in research and the necessity of universal standardization of the equipment has been discussed.

Computer automated motion analysis of crossbred bull spermatozoa and its relationship with in vitro fertility in zona-free hamster oocytes

The objective of this study was to determine the effective relationship between different motion characteristics of bull spermatozoa assessed by computer assisted semen analyzer (CASA) and in vitro fertilization percentage in zona-free hamster oocytes. A total of 64 frozen semen samples from 16 different crossbred bulls (Bos taurusxBos indicus) with four ejaculates from each bull were taken for analysis. Various motion characteristics of spermatozoa like progressive motility, path velocity, progressive velocity, beat cross frequency, straightness and linearity were recorded. Hypo-osmotic swelling test and sperm penetration bioassay were conducted to assess the membrane integrity and fertilization percentage of spermatozoa respectively. Significant positive correlation (P<0.01) was found between fertilization percentage and progressive motility (r=0.791) and between velocity parameters (VAP; r=0.612 and VSL; r=0.625) and fertilization percentage. Among different CASA variables, progressive motility alone contributed to 62.6% variation in the fertilization percentage. The velocity measurements (VAP and VSL) together with progressive motility and %HOS spermatozoa contributed to 66.1% of variation in fertilization percentage which was found to be significant (P<0.05).

Influence of pre-insemination douching and different semen extenders on fertility and hatchability of white Leghorn eggs

1. White Leghorn hens were artificially inseminated twice weekly with undiluted semen or semen diluted (1:3) in Tris buffer, pH 6.8 or saline solution (9 g NaCl/l); with or without pre-insemination douching of the vagina with a solution of ampicillin. 2. Pre-insemination douching reduced the bacterial load of the vagina, resulting in an improvement in fertility and hatchability, with a proportionate reduction in the embryonic mortality. 3. The fertilising and hatching abilities of saline-diluted semen were comparable with those of undiluted semen. 4. Dilution of semen with Tris buffer significantly reduced fertility, but not hatchability.