The objective of this study was to evaluate the importance of environmental and genetic factors affecting semen quality; sperm volume (SV), sperm concentration (SPCO), total sperm (TS), fresh sperm motility (FSM), total fresh motile sperm (TFMS), post thaw sperm motility (PTSM), total post thaw motile sperm (TPTMS), number of produced payout (NPP), number of fresh motile sperm in each milt ejaculation (NFMSE), motility before and after the freezing (MBATF) and number of post thaw motile sperm in each milt ejaculation (NPTMSE). We used polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) in 83 bulls belonging to two progeny test centers.The BB genotype was omitted from analysis.Season of collection had a significant effect on sperm volume (SV)(P<0.006), sperm concentration (SPCO)(P<0.0038), fresh sperm motility (FSM)(P<0.0001), post thaw sperm motility (PTSM)(P<0.001), total post thaw motile sperm (TPTMS)(P<0.0075), number of produced payout (NPP)(P<0.0247), number of fresh motile sperm in each milt ejaculation (NFMSE)(P<0.0012) and motility before and after the freezing (MBATF)(P<0.0001) but did not significantly affect TS (P<0.438), total post thaw motile sperm (TPTMS)(P<0.3606) and number of post thaw motile sperm in each milt ejaculation (NPTMSE)(P<0.1106). The interaction of seasons with follicle-stimulating hormone and semen quality traits only significantly affect sperm volume (SV)(P<0.0435), sperm concentration (SPCO)(P<0.008) and number of produced payout (NPP)(P<0.0119). Genetics and environmental factors clearly contribute to semen production in Holstein bulls. پرونده مقاله

The present study was aimed to examine the association of bovine follicular stimulating hormone gene polymorphism with sperm quality traits including sperm volume (SV), sperm concentration (SPCO), total sperm (TS), fresh sperm motility (FSM), total fresh motile sperm (TFMS), post thaw sperm motility (PTSM), total post thaw motile sperm (TPTMS), number of produced payout (NPP), number of fresh motile sperm in each milt ejaculation (NFMSE), motility before and after the freezing (MBATF) and number of post thaw motile sperm in each milt ejaculation (NPTMSE).We used polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) in 83 bulls belonging to two progeny test center. The frequency of the A (PSTI+) and B (PSTI-) alleles were 0.675 and 0.325, respectively. The genotype frequency for AA and AB were 0.35 and 0.65, respectively. The BB genotype was omitted for analysis.Mixed and probity models analyses of sperm quality traits considering genotype and environment as fixed effects and animal as a random effect suggested that sire was a significant source of variation (P<0.001) in all traits.The AB genotype resultedin a significant increase in TS (P<0.0425), NPP (P<0.0302) traits greater than AA genotype.However, AA genotype had significant effect on PTSM (P<0.0001).But not on sperm volume (SV) (P=0.1749), sperm concentration (SPCO) (P=0.1423), fresh sperm motility (FSM) (P=0.5327), number of post thaw motile sperm in each milt ejaculation (NPTMSE) (P=0.5249), total post thaw motile sperm (TPTMS) (P=0.3982), total fresh motile sperm (TFMS) (P=0.2667), total post thaw motile sperm (TPTMS) (P=0.5898) and motility before and after the freezing (MBATF) (P=0.1785). These results indicate that new molecular markers associated with sperm quality traits can be used in marker-assisted selection in bulls. پرونده مقاله

The present study was conducted to investigate the possibility of using a modified in vitro gas production technique in place of the nylon bag method to estimate protein degradability of alfalfa hay in ruminants. In the in situ experiment dacron bags were filled with 3 g alfalfa hay. This was incubated in the rumen of three ruminally cannulated Ghezel rams for the periods of 0, 2, 4, 8, 12, 16, 24, 36 and 48 h. At the end of the experiment, dry matter, organic matter and crude protein degradability (CPD) were calculated. In the in vitro experiment, buffered rumen fluid was prepared in a solution of 19:1 artificial saliva to rumen fluid, which was pre-incubated by rapidly fermentable carbohydrates for 4 h. After pre-incubation, 30 mL of the buffered rumen fluid were added to 100 mL syringes, containing the alfalfa sample, with 7.5 mg N. The samples were incubated for 2, 4, 6, 8, 12, 16, 24, 36, 48, 60 and 72 hours, after which net gas production was computed. In the third experiment, 25 grams of faeces were mixed with 50 mL of artificial saliva, which was then made up to 1 liter by adding more artificial saliva and filtered. Then, the suspension was pre-incubated for 4 h. After pre-incubation, the same steps used to measure gas production were conducted. Results showed that there were significant differences between gas production with rumen liquor and faeces suspension at 2, 4, 24, 36 and 48 h of incubation, while no significant differences were found at other incubation times. There was a close relationship between crude protein degradation at different times and amount of gas production using rumen liquor [CPD= 58.93 + 0.32 gas (r2=0.76, n=18)] and fecal suspension [CPD= 58.38 + 0.27 gas (r2=0.60, n=18)]. The results indicated that faeces suspension can be used instead of rumen liquor as the medium in the gas production method. Development of the gas production technique could result in reducing the need to use fistulated animals in feed evaluation studies. پرونده مقاله

This study was conducted to determine the chemical composition, metabolizable energy, digestibility and ability of gas production of Poa trivialis. Samples was collected at three phenological stages including: vegetative growth, flowering and seedling on two different elevations of 1300 to 1500 m and 2000 to 1800 m asl in Neor and Hir region as the first and second sites, respectively. Testing of gas production was performed using Semi-automatic gas producers machine WT-Binder 87532 Model (made ​​in Germany). Fistulated castrated male sheeps were used for preparation of required rumen fluid. Results show that more crude protein and less cell wall were in the vegetative growth stage. Gas production was higher in the first stage in comparison with other growing stages. The amounts of gas production of soluble and insoluble structures at the first and second sites were 75.63 and 81.50 mL, respectively. Metabolizabe energy of Poa triviali was2.38 in the first site and in the second site 2.48 Mcal/kg DM in the vegetative growth stage. Collected samples from the second site had more metabolizabe energy, digestibility, degradability and gas production in comparison with the results of the first site. پرونده مقاله