الفهرس 
Introduction
Physical evaluation of semenOnly 14 pages are availabe for public view
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Abstract
The current study was conducted atthe International Livestock Mangement Training Center (ILMTC), Sakha belonging to the Animal Production Research Institute, Agricultural Research Center, Ministry of Agriculture. This study aimed to compare different methods of evaluation of Holstein and buffalo semen through assessment of conventional methods for evaluation physical semen characteristics, along with hypoosmotic swelling test and Sephadex column filtration technique. Semen was collected twice weekly from each of five healthy mature Holstein and five buffalo bulls as a ration work of ILMTC. Immediately, after semen collection, one ejaculate was taken from each bull for 8 weeks (40 ejaculates for each species). The collected semen was transferred to a water bath at 37oC. Semen was evaluated for physical semen characteristics including, ejaculate volume, sperm cell concentration and percentage of live, abnormal and intact acrosome spermatozoa. Hypoosmotic swelling test was designed to establish level of osmolarity and incubation time that would give the maximum percentage of curled spermatozoa. Also, extended semen was filtered using Sephadex columnfiltration technique, and sperm motility, livability and abnormality were assessed in the obtained filtrate. The following results were obtained: Physical semen characteristics of raw semen: (1)?The present results indicated some similarity in all physical semen characteristics between the two species including sperm motility, livability, abnormality, intact acrosome percentage and sperm concentration. However, ejaculate volume was significantly (P<0.001) higher by about 79% in Holstein than buffalo bulls. (2)?Holstein semen contained significantly (P<0.001) higher total sperm output /ejaculate in terms of total count of spermatozoa (10 vs 6 x 109/ejac.), live (7.4 vs. 4. x 109/ejac.), normal (9.6 vs. 6.0 x 109/ejac. and spermatozoa with intact acrosome (8.6 vs. 6.3 x 109/ejac.). (3)?In raw semen, the correlation coefficients were positive and significant between motility and livability percentage, being lower in Holstein (r=0.588) than in buffalo (r=0.784) semen. However, insignificantly negative correlation was obtained between motility and abnormality in Holstein (r=0.089) and buffalo (r=0.24) semen. Correlation of motility percentage and percentage of spermatozoa with intact acrosome was insignificantly poorer in Holstein (r=0.27) than in buffalo (r=0.18) semen. On the other hand, motility percentage correlated significantly with each of sperm concentration (r=0.359) and ejaculate volume (r=0.337) in case of Holstein semen. However, the correlation between sperm motility percentage and sperm concentration was insignificantly poorer (r=0.068) and between motility and ejaculate volume was significantly (P<0.001) stronger and negative (r=0.439) in case of buffalo bulls. Hypoosmotic swelling test (HOStest): (1)?As a response to HOStest, buffalo spermatozoa showed significantly (P<0.05) higher percentage of curling than Holstein ones at all osmolarity levels (50, 100, 150, 200 and 300 mOsm) and incubation times (0, 60 and 120 min). (2)?In both species the maximum curling percentage (P<0.05) was observed in semen solutions of 50 mOsm (82.5 vs. 73.8%) forHolstein and buffalo semen, respectively. The species differences were significant (P<0.01). (3)?The maximum curling occurred significantly (P<0.05) at 120 minutes of incubation in case of Holstein (67.6%) and at 60 minutes in case of buffalo (75.2%). (4)?With different characteristics of raw semen, there was positive correlation between percentage of curled spermatozoa and livability percentage and significant negative correlation between curling percentage and sperm abnormality percentage as well as a significant positive correlation between curling percentage and sperm motility percentage. (5)?It was concluded that HOStest better be carried out at 0 or 60 minutes of incubation with semen solution of 150300 mOsm osmolarity level in both species. (6)? It was concluded also that buffalo semen shows higher sensitivity to the HOStest that Friesian semen, and therefore it is recommended to use the HOStest for evaluation of buffalo semen. Sephadex column filter technique: (1)?As a result of filtration of extended semen using Sephadex column filtered semen of both species showed significant (P<0.05) improvement in motility, livability and abnormality of spermatozoa, however, sperm concentration was reduced significantly (P<0.05). (2)?Improvements of sperm livability and the reduction in sperm concentration (proportional to the prefiltration value) were significantly (P<0.05) higher in Holstein than buffalo semen (15.5% and ـ52.4% vs. 13.2 and 49.3%, respectively). However, improvement of motility and abnormality of spermatozoa did not differ significantly between Holstein (25.4 and ـ57.8%) and buffalo (26.6 and ـ54.5%), respectively. The present results indicate that beside the conventional methods of evaluation of different physical characteristics, HOStest provides a precis technique for measuring alterations in sperm viability and membrane integrity of spermatozoa. Thus it could be used as an important additional indicator of male fertility. In addition, using Sephadex column filter technique has beneficial effects on improving spermatozoa quality, by increasing motility, livability and reducing abnormality of spermatozoa.