The aim of this study was to investigate the effect of zinc (Zn) oxide nanoparticles (ZnONPs) on bovine sperm quality after cryopreservation. Semen samples were collected from four healthy, mature Holstein bulls twice a week. The samples with critical quality were then pooled and assigned into four different groups including different concentrations of ZnONPs (0, 0.1, 1.0 and-10 µg/mL of extender). The samples were frozen by using a semi-automatic device and kept until the evaluation. After thawing, total (TM) and progressive -motility (PM), membrane integrity and functionality, acrosome integrity, DNA fragmentation and malondialdehyde (MDA) concentration were assessed. The different concentrations of ZnONPs did not significantly affect TM and PM of bull spermatozoa, when compared to the control (P≥0.05). The percentage of fast- moving spermatozoa was higher in the treatment supplemented either with 0.1 or 1.0 µg ZnONPs in comparison with the control (P<0.05). Moreover, the results indicated that membrane integrity and functionality and also acrosome integrity of the group treated with 1 µg/mL ZnONP1- was significantly higher than control (P<0.05), while, the percentage of sperm with damaged DNA and MDA concentration was significantly lower in ZnONP1 in comparison with the control (P<0.05). In conclusion, adding 1 µg/mL ZnONP to semen extender, could improve post-thaw bull spermatozoa quality. پرونده مقاله

Enterotoxigenic Escherichia coli K99 is one of the dominant pathogens associated with diarrhea of calves. Immunoglobulin Y (IgY), has been used as an inexpensive alternative to antibiotics for the prevention and therapy of several bacterial infections. The study aimed to prepare IgY antibodies against E. coli K99 and to investigate its in vitro effectiveness. E. coli K99 was grown in the tryptic soy broth, and the bacterial suspension was inactivated by formaldehyde. Thirty White Leghorn hens allocated to control and treatment groups. 1 mL of the prepared bacterial suspension or sterilized physiological serum emulsified with Freund’s complete adjuvant was injected at two weeks interval to the hens in treated or control group. The total IgY was purified with polyethylene glycol (PEG) 6000 from egg yolks (EY). Purified IgY fractions were processed for protein concentrations by Bradford assay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze purified IgY fractions. An indirect enzyme-linked immunosorbent assay (ELISA) method was used to measure the specific IgY titers in serum and EY. The ability of non-specific and anti-E. coli K99 IgY antibody at 100 and 200 mg/mL concentration was evaluated by growth inhibition assay in vitro. According to the ELISA data, total IgY concentration in serum and EY of control was relatively constant, while increased in the treatment group (p <0.05). The level of binding activity of specific IgY in serum and EY increased in immunized hens (p <0.05). Specific IgY had the highest activity for bacterial inhibiting growth at the level of 200 mg/mL. These results suggested the prepared IgY antibodies could inhibit E. coli K99 in vitro growth. پرونده مقاله

The aim of this study was to evaluate the effect of supplemental multispecies probiotics on milk production and reproductive performance of postpartum lactating Holstein cows. Ninety-six cows were assigned to one of two dietary treatments from day 1 to 85 postpartum. Treatments were including 1) control, a standard diet, (n=48) and 2) probiotic, same as control plus 3 g/cow/day of the probiotics supplement (Hypro-cow®) (n=48). In a subset of eight animals per group, dry matter intake (DMI), body condition score (BCS), rectal temperature (RT), respiration rate (RR), and heart rate (HR) were assessed, and blood samples and milk yield recorded. Milk samples were analyzed every 2 wk. for fat, protein and somatic cell. Blood samples were collected on day 0, 14, 28, 42, 56, 70 and 85 post-partum for determining plasma total protein, albumin, creatinine, urea, glucose and triglyceride concentrations and activity of transaminases (aspartate aminotransferase and alanine aminotransferase). In all animals, occurrence of health disorders (i.e. metritis, endometritis, laminitis and mastitis), calving to first estrus interval, days open (DO), conception rate to first insemination and pregnancy up to 85 and 120 DIM were evaluated. Probiotic supplementation increased DMI (17.43±0.11 vs. 14.12±0.17) and BCS (3.36±0.16 vs. 3.14±0.23) (P<0.05). Mean daily milk yield (36.34±0.32 vs. 34.36±0.38) (P=0.05), and all milk components increased (P<0.05) by probiotic supplementation. Plasma concentrations of urea (10.28±0.63 vs. 11.08±0.47) and creatinine (1.00±S0.25 vs. 1.23±0.63) was lower (P<0.05) in supplemented group compared to control group. The incidence of laminitis (20.5±0.61 vs. 27±0.31) and metritis (32±0.03 vs. 40±0.81) were reduced (P<0.05) in supplemented cows compared to control cows. Interval from calving to first estrus and days open (DO) was reduced by 4 and 26 days, respectively (P<0.05) in treated cows. The conception rate was greater in probiotic group (22.5%) than control group (12.5%). In conclusion, supplemental multi-species probiotics during postpartum has a beneficial effect on productive and reproductive performance of dairy cows. پرونده مقاله

The effects of dietary live Saccharomyces cerevisiae as a probiotic on milk production, oxidant/antioxidant status, and lipid metabolism of Holstein dairy cows through the transition and early lactation period during the summer season were investigated. Twelve lactating multiparous dairy cows were randomly allocated to two dietary treatments (n=6) including a control and probiotic-fed groups. Blood samples were collected on days -21, 0, 14, 28, 42, 60 days relative to parturition and analyzed for calcium, iron, cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, total antioxidant capacity, malondialdehyde, and albumin. Serum concentrations of triglycerides, cholesterol, and low-density lipoprotein were lower in the probiotic-fed cows compared to those offered the control diet. Albumin concentration did not differ between the groups. The contents of total antioxidant capacity and high-density lipoprotein in the yeast-fed group was greater than the control group (P=0.01 and 0.02, respectively). In addition, serum calcium and iron tended to be higher in the yeast-fed group (P=0.08). Malondialdehyde level did not change between groups, but there was a decrease at calving time in the probiotic-fed group. Yeast-fed cows produced more milk and had higher concentrations of milk fat and non-fat solids than control cows (P<0.05). Rectal temperature was lower in the probiotic-fed group on parturition day. In conclusion, dietary supplementation of Saccharomyces cerevisiae in dairy cows may be a beneficial strategy to alleviate the heat stress and improve the antioxidative defense system and milk production during the transition and the early lactating period. پرونده مقاله

Adding antioxidants to semen extenders could reduce post-thaw sperm damages. Glutathione is an important intracellular antioxidant that has free radicals scavenging properties and multiple effects on DNA and protein synthesis. In the present study, effects different levels of reduced glutathione (GSH) containing 0 (control), 1.0, 2.5, or 5.0 mM in a nanomicelle-based extender on post-thaw quality of bovine sperm were investigated. Initially, lecithin was added to a tris-based extender containing GSH. The mixture was then emulsified by slowly shaking and sonification so that nano size of particles was obtained. Thirty-six ejaculates from six Holstein bulls were used. The post-thaw quality parameters including computer-assisted sperm analysis of motility, plasma membrane functionality, membrane integrity, acrosome integrity, morphology and level of apoptosis were measured. Compared to the control medium, the total motility and membrane integrity were significantly better in samples containing 2.5 mM GSH (67.3±1.2% vs. 73±1.2% and 71.3±1.5% vs. 77.6±1.5%, respectively). The extender supplemented with 2.5 mM GSH had the highest percentage of viable sperm during apoptotic test. In conclusion, supplementation of lecithin nanomicelle-based extender with 2.5 mM GSH reduced damages to bovine sperm during cryopreservation. پرونده مقاله