The effect of adding pyridoxine to soybean lecithin-based extender on goat semen quality parameters after the freeze-thawing process.

BACKGROUND: Supplementing the semen extender with various antioxidants can increase the quality of semen. AIMS: The aim of the present study was to investigate the addition of pyridoxine (vitamin B6), a phenolic compound with antioxidant properties, to soybean lecithin extender on motility and quality indices of goat sperm after freezing-thawing process. METHODS: Semen was collected at weekly intervals from four Mahabadi goats, mixed, and was divided into 7 subsamples. They were then diluted with the basal extender supplemented with 0, 2, 4, 6, 8, 10, and 12 mM pyridoxine. Following freeze-thawing process, quality parameters such as sperm motility characteristics, viability, plasma membrane integrity, and malondialdehyde content were determined. RESULTS: The results showed that pyridoxine at the level of 6 mM caused the highest total motility rate (P<0.05). Progressive sperm motility was highest at the 4, 6, and 8 mM pyridoxine (P<0.05). Although the control group showed the least progressive motility, it was not statistically significantly different from the 12 mM level. Among the pyridoxine levels, the 6 mM level recorded the best performance in term of plasma membrane integrity, sperm viability, and decreasing malondialdehyde concentration compared to the control group (P<0.05). CONCLUSION: The findings indicated that soybean lecithin extender supplemented with 6 mM pyridoxine can improve motility and quality parameters such as viability, plasma membrane integrity, and reduce oxidative stress of goat sperm after thawing.

Supplementation of Plant-Based Cryopreservation Medium with Folic Acid Conserves the Quality of Bulk Post-Thawed Spermatozoa.

The current study evaluated the effects of cryopreservation medium supplementation with folic acid as an antioxidant on post-thawed semen quality in bulk. Semen samples were collected from four proved Iranian Mahabadi bulls and diluted in extender containing 1.5% soybean lecithin. The diluted semen was assigned into six parts and supplemented with different doses of folic acid as follows: FA0 (extender without folic acid), FA0.05, FA0.1, FA0.2, FA0.4, and FA0.8 (extenders containing 0.05, 0.1, 0.2, 0.4, and 0.8 mM folic acid, respectively). Then, the semen samples were cryopreserved in liquid nitrogen. Sperm motility and velocity parameters, membrane integrity, abnormal morphology, viability, and lipid peroxidation were evaluated after thawing. In the results, FA0.05 presented higher (p≤0.05) total motility, progressive motility, membrane integrity, and viability and lower lipid peroxidation compared to other groups. Abnormal morphology was not affected (p>0.05) by treatments. In conclusion, supplementation of cryopreservation medium with 0.05 mM folic acid is a helpful method to conserve the quality of post-thawed semen in bulk.

Combined effect of probiotics and specific immunoglobulin Y directed against Escherichia coli on growth performance, diarrhea incidence, and immune system in calves.

Enterotoxigenic Escherichia coli (ETEC) K99 is one of the major pathogens associated with calf diarrhea. The induction of passive immunity in animals by immunoglobulin Y and using probiotics are inexpensive alternatives to antibiotics for the prevention and treatment of a number of bacterial infections, including diarrhea. Hence, the aim of this research was to evaluate the impact of dietary probiotics and ETEC K99-specific egg yolk antibody supplements, alone and in combination with each other, on health and growth parameters, diarrhea incidence and immune stimulation in newborn Holstein calves. One hundred and twenty neonatal calves were allocated randomly into 4 dietary groups (n = 30 per group) received colostrum/milk without any additives (control group), or supplemented with egg yolk powder contained E. coli K99-specific antibody (Ab group; 1 g/day), a commercial probiotic, Hypro-calves (Pro group; 3 g/day), and their combination (Ab+Pro group), from day (d) 1 to d28 of age. Analyses of the growth parameters, feed efficiency, fecal score, and microbiota and immune function were carried out on d0, 14, 21, and 28 of the experiment. Calves in Ab or Ab+Pro group had higher (P < 0.05) average daily gain compared to control and Pro groups during 0-14d. Feed efficiency of calves in Ab and Ab+Pro groups was significantly higher than that in control group during the period of 0-14d; however, no significant differences were observed in 0-28d period. Diarrhea prevalence and fecal score in Ab+Pro group were lower than control group (P < 0.05). Calves in Ab+Pro group had the lowest number of fecal E. coli in comparison to other groups on d28 (P < 0.05). Feeding Ab+Pro supplement increased (P < 0.05) concentrations of blood IgA and serum CD4 compared to the control group. Likewise, calves in Pro group had higher CD4 levels as compared to the control calves (P < 0.05). Serum concentration of interferon-gamma in control group was lower than other groups (P < 0.05). Overall, these data suggest that feeding a combination of probiotic and specific antibody against ETEC to neonate Holstein calves enhances feed efficiency, boosts immunity, and reduces diarrhea prevalence.

The effect of zinc oxide on rooster semen cryopreservation.

1. Deleterious effects from the freeze-thawing process on post-thawed sperm quality attributes are main limiting factors in cryopreservation. The current study was conducted to determine the effect of semen extender containing zinc oxide (ZnO) on post-thaw rooster sperm quality indices.2. Semen samples from six, 60-week-old broiler breeder roosters were collected weekly during five successive weeks. The samples were mixed and divided into three equal parts and diluted with semen extender containing different levels of ZnO; 0 (ZnO-0), 1 (ZnO-1) or 2 (ZnO-2) µg/ml. After thawing, motility and velocity parameters, plasma membrane functionality, apoptotic like changes, mitochondrial membrane potential (MMP), and DNA fragmentation index (DFI) were evaluated.3. Results showed that the addition of ZnO in the extender quadratically affected (P < 0.01) total motility (TM), progressive motility (PM), and average path velocity (VAP) with the highest values were noted in the ZnO-1 group. Levels of ZnO quadratically affected percentages of live (P < 0.01), apoptotic (P < 0.03) and dead (P < 0.10) spermatozoa, where the highest percentage of live, and the lowest percentage of apoptotic or dead spermatozoa was for the ZnO-1 group. Although adding ZnO quadratically affected plasma membrane functionality and MMP (P < 0.01), it did not affect (P > 0.05) DFI.4. In conclusion, there were some beneficial effects of ZnO supplementation in semen extender on post-thawed rooster sperm quality which may result in a better freezability.

Lecithin nanoparticles enhance the cryosurvival of caprine sperm.

This study was designed to compare the effects on goat spermatozoa cryosurvival of nano-lecithin-based (NL), lecithin-based (L) and egg yolk-based (EY) extenders. Ejaculates were collected from four fertile goats using artificial vagina and diluted with nine extenders. NL and L were tested at concentrations 1%, 2%, 3% and 4% (w/v), versus 15% (v/v) egg yolk-based extender. Overall, sperm quality (higher motility, viability and HOST, and lower apoptosis) was higher for NL than for L treatments (P < 0.05 for most cases, except for 1%). NL at 1% and especially at 4% showed lower motility and viability than 2% or 3% NL. NL at 2% achieved a better performance (P < 0.05) than EY for VCL (131.5 ±â€¯1.3 vs. 120.3 ±â€¯1.9 µm/s), VSL (43.9 ±â€¯1.5 vs. 35.8 ±â€¯1.4 µm/s), LIN (35.7 ±â€¯0.6 vs. 29.3 ±â€¯0.8%), WOB (47.0 ±â€¯0.5 vs. 43.9 ±â€¯0.9%) and viability (66.4 ±â€¯1.7 vs. 52.7 ±â€¯1.9%). Late apoptotic spermatozoa were also lower in 2% NL compared to EY (16.0 ±â€¯0.5 vs. 26.3 ±â€¯1.1%, P < 0.001). EY and 2% NL were compared in an IVF trial, with no significant differences in cleavage (68.8 vs. 70.8%) or blastocyst ratios (21.3 vs. 20.8%). In conclusion, using 2% nanolecithin in semen dilution could improve sperm cryosurvival of goat.

Effects of live yeast dietary supplementation on hormonal profile, ovarian follicular dynamics, and reproductive performance in dairy cows exposed to high ambient temperature.

Two experiments were conducted to investigate the effects of dietary supplementation with live yeast culture on hormonal profile, ovarian follicular dynamics and reproductive performance of lactating dairy cows exposed to high ambient temperature. In Expt. 1, Holstein cows were fed a diet with (n = 6) or without (n = 6) 4 g yeast/h/d from 21 d before expected calving date until 8 weeks postpartum. Concentrations of glucose, insulin, insulin like growth factor-I (IGF-I), estradiol-17ß (E-17ß) and progesterone (P4) were determined in plasma, and transrectal ultrasonography was used to monitor ovarian follicular dynamics. In Expt. 2, 150 Holstein cows (75/dietary group) received same diets as Expt. 1 with the exception that diets were fed from d 1 to d 70 postpartum. The effect of dietary treatments on reproductive performance was examined. In Expt. 1, plasma IGF concentrations during dietary treatment were higher (P = 0.05) in cows fed diets supplemented with yeast. On d 60 postpartum, average plasma concentrations of glucose (48.3 vs. 41.0 mg/dL) and insulin (0.90 vs. 0.23 µU/mL), were also greater in cows fed diets supplemented with yeast compared to that in cow fed diets without supplementation. Similarly, plasma concentrations of E-17ß at estrus (P = 0.016) and P4 on d 10 of the estrous cycle (P = 0.021) were greater in yeast-supplemented cows. Moreover, yeast supplementation resulted on average in an estrous cycle 2.6 d shorter (P = 0.05) and in the development of larger ovulatory follicles (18.4 vs. 17.2 mm in diameter; P < 0.01). In Expt. 2, days open were fewer and the proportion of pregnant cows at 120 and 150 d postpartum were greater (P < 0.01) in cows fed diets supplemented with yeast compared to those receiving diets without yeast. In summary, cows fed diets supplemented with yeast had greater plasma IGF-I, E-17ß and P4 concentrations, larger ovulatory follicles, shorter estrous cycles, and improved reproductive performance. Therefore, live yeast dietary supplementation could enhance lactating dairy cow's fertility during heat stress through improvement in hormonal profile and development of larger ovulatory follicles.

Effects of supplemental conjugated linoleic acids (CLA) on fresh and post-thaw sperm quality of Holstein bulls.

This study was designed to investigate the effects of feeding-protected conjugated linoleic acid (CLA) on the semen production and sperm freezability in Holstein bulls. Twelve bulls were randomly assigned to two groups (n = 6 per group). Bulls received the normal diet (control group) or the normal diet top-dressed with 50 g of CLA (treated group) for 10 weeks. The control group received 40 g/day calcium soap of fatty acid. Fresh and post-thaw semen quality was assessed on ejaculates collected at the 0, 4, 6, 8 and 10 week of supplementation. Semen evaluations including sperm concentration, motion characteristics (subjective and computer-assisted), viability (Eosin-Nigrosin), membrane integrity (hypo-osmotic swelling test) and abnormality were conducted. Semen volume, sperm concentration and total sperm output were not affected by dietary treatment (p > .05). The proportion of spermatozoa with abnormal morphology in fresh semen significantly increased (p < .05) in the CLA-fed group compared to control group. Also, in CLA-fed group, the proportion of post-thaw spermatozoa with abnormal morphology at week 10 of trial was significantly higher in CLA than control group (p < .05). Progressive motility tended to be increased in the CLA-fed group, although dietary supplementation did not affect other CASA parameters or viability in fresh and frozen-thawed sperm. In this study, CLA supplementation had little positive effect on fresh or post-thaw sperm quality of Holstein bulls.

Effect of dietary fish oil supplementation on ram semen freeze ability and fertility using soybean lecithin- and egg yolk-based extenders.

Ram semen cryopreservation is not efficient for artificial insemination in commercial herds. Beneficial effects of dietary fish oil have been evaluated for cryopreservation of ram semen in soybean lecithin (SL) and egg yolk (EY)-based extenders. A factorial study (two diets × two extenders) was used to analyze the effects of two diets supplemented with fish oil (n-3 fatty acid) or palm oil (saturated fatty acids; [SFAs]) to freeze ram semen in two extenders containing SL or EY. Motility characteristics, membrane integrity, abnormal morphology, mitochondria activity, acrosome integrity, apoptotic status, and fertilizing ability were assessed after freeze-thawing. Although diet had significant (P ≤ 0.05) effects on the quality parameters of frozen-thawed sperm, effects of extenders on these traits were not significant (P > 0.05). The higher significant (P ≤ 0.05) percentage of total motility and progressive motility were observed in n-3/SL (44.83 ± 1.56 and 28.33 ± 1.4) and n-3/EY (43.33 ± 1.56 and 28.50 ± 1.4) than SFA/SL (32.16 ± 1.56 and 14.00 ± 1.4) and SFA/EY (31.66 ± 1.56 and 12.66 ± 1.4) groups. Moreover, n-3/SL and n-3/EY produced the higher significant (P ≤ 0.05) percentage of membrane integrity of sperm (39.83 ± 1.4 and 37.33 ± 1.4) than SFA/SL and SFA/EY (29.83 ± 1.4 and 28.5 ± 1.4). For viability results, the higher significant percentage of live sperm was observed in n-3/SL and n-3/EY (43.16 ± 1.38 and 45.66 ± 1.38) than SFA/SL and SFA/EY (28.66 ± 1.38 and 27.5 ± 1.38). For fertility trials, n-3-based diets (n-3/SL and n-3/EY) improved significantly (P ≤ 0.05) pregnancy rate (44% and 46%), parturition rate (42% and 42%), and lambing rate (46% and 44%) compared with the SFA-based diets (SFA/SL and SFA/EY). No interaction effects have been found between diets and extenders (P > 0.05). It seems that dietary fish oil can improve the semen performance after freezing-thawing process and artificial insemination aside from type of extenders.

Fertility and flow cytometry study of frozen-thawed sperm in cryopreservation medium supplemented with soybean lecithin.

Semen cryopreservation can provide genetic resources for a large number of females from a small number of superior males. Optimization of cryopreservation media to achieve the highest quality of post-thaw semen is crucial. Soybean lecithin has evaluated as a plant-based cryoprotectant for substitution of egg yolk in ram semen extender. Flow cytometric and fertility assessments were applied following cryopreservation procedure in two experimental groups (SL group: extender containing 1% w/v soybean lecithin and EY group: extender containing 20% v/v egg yolk). The higher percentage of live sperm and the lower percentage of dead sperm were obtained in SL (47.66 ± 1.38, 52.33 ± 1.69, respectively) extender compared to EY (41.16 ± 1.38, 58.83 ± 1.69). For motion characteristics, plasma membrane integrity, acrosome integrity and mitochondria activity, no significant difference was observed between SL and EY extenders. In artificial insemination experiment, there was no significant difference in pregnancy rate, lambing rate and twining rate between SL and EY extenders. It can be concluded that SL extender can be an efficient alternative extender to preserve ram sperm during cryopreservation procedure without adverse effects.

Protective role of glutathione in buck semen cryopreservation.

The aim of this study was to determine the effect of low levels of glutathione on post-thawed buck sperm quality. In this experiment, different concentrations of glutathione [0 (LG-0), 0.5 (LG-0.5), 1 (LG-1), 1.5 (LG-1.5), and 2 (LG-2) mM] were added in a soybean lecithin-based extender. A total of 16 ejaculates from four bucks were collected and pooled. Each pooled sample was divided into five equal parts and each part was diluted by one of the above mentioned groups. After freeze-thawing process, motility and velocity, plasma membrane integrity and functionality, and apoptosis features of spermatozoa were evaluated. The results of this experiment showed that total motility (50.75 ± 2.33), plasma membrane integrity (55.75 ± 3.01) and functionality (46.75 ± 2.79) were higher in LG-1 extender compared to other extenders (P<0.05). The percentage of live spermatozoa (53.23 ± 3.26) was higher in LG-1 extender compared to other extenders, with the exception of LG-1.5 extender (P<0.05). Also, the percentage of late apoptotic spermatozoa (21.33 ± 1.63) was lower in LG-1 extender compared to other extenders (P<0.05). In conclusion, our results showed that GL-1 extender resulted in higher post-thawed buck sperm quality compared to other extenders.

The endometrial expression of prostaglandin cascade components in lactating dairy cows fed different polyunsaturated fatty acids.

Feeding n-6 polyunsaturated fatty acids (PUFA) increases the endometrial percentages of linoleic and arachidonic acids (AA), enhances the synthesis of prostaglandin F2α (PGF2α), and improves uterine health. In contrary, the n-3 PUFA, eicosapentaenoic acid, and docosahexaenoic acid may play pivotal roles by suppressing the synthesis of uterine PGF2α, a component being centrally involved in the control of the bovine estrous cycle and in early embryo survival. The objectives of the present study were to determine the effect of feeding a diet enriched in either α-linolenic acid (n-3) or linolenic acid (n-6) on the uterine expression of genes related to prostaglandin cascade and uterine release of PGF2α (measured as 13, 14-dihydro-15-keto PGF2α [PGFM]). From calving to 60 days in milk, cows (n = 24) were fed isonitrogenous, isocaloric, and isolipidic diets that differed in the ratio of n-3/n-6 PUFA. Treatments including palm oil ([PLM]; saturated FA, n = 8), soybean whole roast ([SOY]; n-6, n = 8), and linseed extruded ([LIN]; n-3, n = 8). At 30 days in milk, the ovulatory cycles of cows were synchronized using 2 injections of PGF2α with a 14-day interval. On day 15 postovulation, cows were injected with oxytocin and blood samples were collected to monitor the uterine release of PGF2α (measured as PGFM) and uterine endometrial biopsies were prepared to evaluate the expression of genes related to prostaglandin cascade (prostaglandin F synthase [PGFS], prostaglandin E synthase [PGES], prostaglandin endoperoxide synthase-2 [PGHS-2]), phospholipase A2 (PLA2), peroxisome proliferator-activated receptors [PPAR]). Results showed that uterine endometrial PPAR-δ genes were higher in cows fed LIN (3.17-fold) compared with cows fed PLM or SOY (P < 0.05). The messenger RNA (mRNA) level of PGES in the LIN group was threefold as high as those found in SOY and PLM diets (P < 0.05). The mean relative gene expression of PLA2 and PGFS was increased in animals fed the SOY diet (2.4- and 1.7-fold, respectively) compared with LIN and PLM diets (P < 0.05). The expression of mRNA for the PGHS-2, PPAR-α, and PPAR-γ was not influenced by the diet effect. Dietary inclusion of soy FAs was associated with an increase in the PGFM concentration, possibly through an increase in the expression of genes involved in prostaglandin cascade. The uterine concentration of PGFM, however, was decreased in cows fed diets containing n-3 FAs.

Plasma concentrations of PGFM and uterine and ovarian responses in early lactation dairy cows fed omega-3 and omega-6 fatty acids.

A total of 120 dairy cows were assigned randomly to three diets to determine the effects of omega-6 or omega-3 fatty acid (FA) supplementation on uterine diseases, ovarian responses, and blood concentrations of estradiol, progesterone, and PGFM in lactating Holstein dairy cows. Diets contained either protected palm oil (C), extruded linseed (L), or roasted whole soybeans (S), and they were fed from calving to Day 70 postpartum. Estrous cycles were synchronized and ovarian follicular development was monitored daily for an entire cycle. There were no differences among diets in the incidence of lameness, mastitis, or metritis, but the incidence of clinical endometritis was lower (P < 0.05) in cows fed S (0%) compared with cows fed C (28.2%) and L (20.5%). Uterine involution in cows fed S occurred 3.77 and 2.78 days earlier, respectively, than in those fed C and L. The PGFM response 60 minutes after an oxytocin challenge was highest for cows fed S and lowest for cows fed L. Mean plasma progesterone concentration on Day 15 of the synchronized cycle was higher in cows fed S (14.5 ng/mL) and L (15.0 ng/mL) than in those fed C (12.0 ng/mL). The ovulatory follicle on Day 21 of the estrous cycle (estrous = Day 0) was larger in cows fed S (16.1 ± 0.9 mm) and L (15.7 ± 0.7 mm) compared with cows fed C (13.2 ± 0.87 mm; P = 0.02) but there were no significant differences between cows fed diets S and L. The mean number of small and medium follicles and diameter of subordinate follicle were similar among diets. In conclusion, feeding a source of omega-6 FA can be a strategy to improve uterine health after calving, although a source of omega-3 FA such as L should be fed after uterine involution to decrease PGF2α secretion.

Effects of different polyunsaturated fatty acid supplementations during the postpartum periods of early lactating dairy cows on milk yield, metabolic responses, and reproductive performances.

In spite of the difficulties in delivering PUFA to ruminants, studies have generally indicated that the PUFA of the omega-6 (linoleic acid) and omega-3 [α-linolenic acid; eicosapentaenoic (EPA), C20:5 omega-3; docosahexaenoic (DHA), C22:6 omega-3] families are the most beneficial to improving reproduction in cows. The objectives were to determine if a diet enriched in α-linolenic acid (omega-3) or linoleic acid (omega-6) would influence milk production and composition, metabolic status, and reproductive performance in lactating dairy cows. High-yielding multiparous Holstein dairy cows (n = 120) with no overt clinical illnesses were blocked according to calving date and parity. Cows were assigned randomly to be fed 1) soybean whole roast (Soy, omega-6, n = 40) or 2) linseed (Lin, omega-3, n = 40) or 3) palm oil as a source of SFA (PO, n = 40) from calving until first heat after 40 d postpartum (dpp), and then half of the cows in each treatment group were switched to receive either Lin or SFA (PO) from first heat after d 40 to 120 dpp. Blood was collected from a subsample of cows. Blood was collected at 14 d intervals for 12 wk, starting on the day of calving. Results showed milk yield and DMI were not affected. Milk compositions were similar (P > 0.08) among diets, except concentration and yield of milk fat percentage, which was less in cows fed Lin (P < 0.05). Uterine involution in cows fed Soy occurred earlier (P < 0.05). Diets affected day to first estrus and day to first insemination in cows (P < 0.05). There were no differences among treatments for percent heat detection, percent pregnancy per first insemination, and percent conception per AI at estrus. Also, there is a trend of pregnancy by 120 d, which is 66.7% for the Lin group vs. 50.91% for the PO group (P < 0.08). Of the 4 pregnancy losses, 2 occurred in PO-PO group and 2 occurred in Soy-PO group, and none occurred in the other 4 treatments. In conclusion, our study showed feeding omega-6 fatty acids during 40 dpp could be a good treatment for early postpartum periods, and a shift to omega-3 fatty acids until 40 d after AI can be considered as a strategy for improving fertility in lactating dairy cows.

Effect of n-3 fatty acids and α-tocopherol on post-thaw parameters and fatty acid composition of bovine sperm.

PURPOSE: This study was designed to determine the combined effects of adding source of n-3 fatty acids (FA) and α-tocopherol (vitamin E, VE) to semen extender on freezability and FA composition of Brown Swiss bull sperm. METHODS: Semen samples were collected from 6 Brown Swiss bulls and pooled. In the first trial, semen was divided into 12 groups including 4 levels of n-3 FA (0, 1, 10, 100 ng ml(-1)) and 3 levels of VE (0. 0.2, 0.4 mM). Motility, viability and fatty acid composition of sperm were measured. RESULTS: The treatment of 10 ng ml(-1) n-3 FA and 0.4 mM VE had the best post-thaw sperm characteristics (P < 0.01). In the second trial, sperm lipid composition of this treatment and control (without FA and VE) was determined. Supplementing n-3 fatty acids during cryopreservation increased docosahexaenoic acid (DHA) and the ratio of n-3 to n-6 FA in sperm before freezing and after thawing. CONCLUSIONS: The results suggest that combining the optimal level of n-3 FA (10 ng ml(-1)) with the highest level of VE tested (0.4 mM) in a semen extender changed the membrane lipid composition and improved freezablity of Brown Swiss bull sperm.

Combined effect of DHA and α-tocopherol supplementation during bull semen cryopreservation on sperm characteristics and fatty acid composition.

The aim of this study was to investigate the effect of adding n-3 fatty acids (FA) and α-tocopherol (VE) to semen extender on freezing ability and FA composition of bull sperm. Semen was collected from 10 Iranian Holstein bulls and was pooled. In the first experiment, semen was divided into 12 groups including 4 levels of n-3 FA (0, 0.1, 1, 10 ng ml(-1) ) and 3 levels of VE (0, 0.1, 0.2 mmol). The treatment of 0.2 mmol VE and 10 ng ml(-1) n-3 FA had the best post-thawed sperm characteristics (P < 0.01). In the second experiment, lipid composition of the latest treatment and control (without FA and VE) was determined. Adding n-3 FA increased docosahexaenoic acid (DHA) percentage before freezing and after thawing. The ratio of n-3 to n-6 before freezing was higher (P < 0.05) in treated group than in control, and this ratio in the fresh sperm was greater than in the post-thawed sperm (P = 0.1). Results suggested that adding DHA accompanied with an antioxidant to an extender could improve cryosurvival of bull sperm via altering membrane lipid composition.

Effect of feeding a docosahexaenoic acid-enriched nutriceutical on the quality of fresh and frozen-thawed semen in Holstein bulls.

The aim of the current study was to investigate the effect of feeding a DHA-enriched nutriceutical on the in vitro quality and sperm motility parameters of fresh and frozen-thawed bull semen assessed by CASA. Samples were obtained from nineteen Holstein bulls used for semen collection at Semen Production Center, Karaj, Iran. Control group (n = 10) were fed a standard concentrate feed while treatment group bulls (n = 9) had this standard feed top dressed with 100 g of a commercially available DHA-enriched nutriceutical. Semen quality was assessed on ejaculates collected at the baseline and after 5, 9, and 12 weeks of supplementation. Classical semen evaluation, assessment of sperm motility (subjective and computer-assisted), viability (eosin-nigrosin), and hypo-osmotic swelling test (HOST) were conducted. Semen volume, sperm concentration, and consequently total sperm output were not affected by dietary treatment (P > 0.05). Feeding the nutriceutical was indeed found to affect sperm motility parameters assessed by CASA after 9 weeks of trial. The treatment has improved total motility (P < 0.01), progressive motility (P < 0.05), average path velocity (P < 0.05), HOST-positive (P < 0.01), and proportion of rapid spermatozoa (P < 0.01) in the fresh semen of bulls. Moreover, the proportion of viable spermatozoa increased (P < 0.05) in the ejaculates collected from nutriceutical-fed bulls compared to the control after 12 weeks of feeding trial. The post-thawed HOST and sperm motility data obtained by CASA did not differ between two groups (P > 0.05). On the other hand, dietary supplementation did not affect body weight, BCS and scrotal circumference. Consequently, it can be concluded that dietary DHA supplementation or its precursors, improve in vitro quality and motility parameters of fresh semen assessed by CASA in Holstein bulls. However, this effect was not pronounced in frozen-thawed semen.

The relationship of plasma leptin concentration and puberty in Holstein bull calves (Bos taurus).

The objective of this experiment was to study the changes of plasma leptin concentration during puberty and its relationship with testosterone level and testis dimensions in Holstein bull calves. Six Iranian Holstein bull calves with approximately 6 months of age were used. Semen evaluation was conducted at 1-month interval to determine the puberty state. To detect the plasma leptin and testosterone changes, blood samples were collected from the jugular vein during pre-puberty (6-7 months of age), puberty (8-9 months of age) and post-puberty (10-11 months of age). In addition, body weight (BW), body condition score (BCS) and testicular width and length were measured at 3-week intervals. The effects of time (age) on total sperm number and percentage of progressive motility of sperm, plasma concentration of leptin and testosterone, amplitude and frequencies of testosterone, BW, BCS, testicular dimensions were significant. Sperm number and progressive motility during post-puberty were higher than those during puberty and pre-puberty. Plasma concentration of leptin during the pre-puberty was higher than those during puberty and post-puberty (p < 0.01). Mean plasma testosterone concentrations during puberty were higher than those during pre-puberty (p < 0.05). BW, BCS and testicular dimensions consistently increased throughout the trial. Results indicated that in growing bull calves, plasma concentrations of leptin decreased during puberty, while circulating testosterone increased.

Effects of dietary n-3 fatty acids on characteristics and lipid composition of ovine sperm.

The fatty acid composition of sperm affects the fertilization rate. The objective was to investigate the effects of dietary fish oil (as a source of n-3 fatty acids) on semen quality and sperm fatty acid composition in sheep. Eight Zandi fat-tailed rams were randomly allocated into two groups and fed either a control diet or a diet supplemented with fish oil. Both diets were isocaloric and isonitrogenous and were fed for 13 weeks, starting in the middle of the breeding season. Semen samples were collected weekly and their characteristics evaluated by standard methods, whereas samples collected at the start and end of the study were assessed (gas chromatography) for sperm lipid composition. Mean (±s.e.m.) sperm concentrations (4.3 × 109 ± 1.3 × 108 v. 3.9 × 109 ± 1.3 × 108 sperm/ml and percentages of motile (77.25 ± 3.34 v. 60.8 ± 3.34) and progressively motile sperm (74.13 ± 1.69 v. 62.69 ± 1.69) were significantly higher in the fish oil group than control. Dietary fish oil increased the proportion of docosahexaenoic acid (DHA, C22:6 n-3) in sperm fatty acid composition. We concluded that feeding fish oil as a source of n-3 fatty acids attenuated seasonal declines in semen quality in rams, perhaps through increased DHA in sperm.

Cloprostenol injection improves reproductive characteristics in low libido Iranian Holstein bulls.

The objective of this study was to determine whether injections of Cloprostenol (PGF2alpha analog) in low libido Holstein bulls can improve seminal characteristics and libido. Ten low libido Iranian Holstein bulls were randomly assigned to two groups and received; (1) 250 microg ofCloprostenol (n=5) or (2) 2 mL of saline (n=5) 30 min prior to collection of semen 2 days per week for 2 months. Reaction time was significantly decreased in treatment group. Duration of ejaculation was significantly increased in treatment group. Semen volume and sperm concentration were greater in treated bulls in compare with controls. The percentage of morphologically normal sperm cells, percentage of live sperm cells, motile sperm cells and post-thaw motile sperm cells were not affected by treatment. Plasma testosterone concentrations were increased approximately two fold after Cloprostenol injection. Overall, injection of Cloprostenol at this dosage and frequency increased libido, semen volume, sperm concentration and plasma testosterone concentration in low libido Holstein bulls.

Nutritive value of some herbages for dromedary camel in Iran.

To prepare standard tables of chemical composition of feedstuffs and to determine digestibility and palatability of different plant species in dromedary camel, this research was carried out by considering the most consuming herbages of Iranian desert rages. The plant species were included Atriplex lentiformis, Alhagi persarum, Seidlitzia rosmarinus, Saueda fruticosa, Haloxylon ammodendron, Tamarix kotschyi, Hammada salicornica, Salsola yazdiana, Salsola tomentosa, Tamarix aphylla and Artemisia sieberi. Thirty samples of the browsing parts were collected from the rangelands of Yazd province in autumn. Chemical composition of samples including Dry Matter (DM), Crude Protein (CP), Crude Fiber (CF), Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Ether Extract (EE), Total Ash (TA), macro elements (Ca, P, Mg, K), micro elements (Fe, Mg, Cu, Zn)and gross energy (GE) were analyzed. The in vitro digestibility was determined by camel rumen liquor in Tilley and Terry method. Palatability of the plants were measured by three mature camels in cafeteria trials. The camels voluntarily fed 11 plant species during one hour for six days. Data were analyzed by GLM method in SAS software. The highest CP (18.3%) and the lowest NDF (40.4%) and ADF (35.4%) were related to Tamarix aphylla. The lowest CP (5.5%) and the highest NDF (72.8%) and ADF (59.6%) were related to Artemisia sieberi. The highest organic matter digestibility in dry matter was related to Haloxylon ammodendron. The results also indicated that Atriplex lentiformis, Alhagi persarum, Seidlitzia rosmarinus, Saueda fruticosa, Haloxylon ammodendron, Salsola tomentosa, Hammada salicornica, Tamarix kotschyi, Salsola yazdiana, Tamarix aphylla and Artemisia sieberi were more pleasure feed, respectively. It was not observed any correlation between %DOMD and chemical composition. Moreover, There was not a consistent relationship between the palatability of herbages with %DOMD or chemical composition.