فصلنامه تحقیقات تولیدات دامی
سال سوم شماره 1 (بهار 1393)

This experiment was conducted to evaluate the addition of seminal plasma to coated spermatozoa after 72 h. Semen was collected from four Taleshi rams by artificial vagina. To prepare coated spermatozoa, semen was collected in tube containing Tris-fructose-15% egg yolk. After initial evaluation, the samples were mixed and centrifuged. After removal of supernatant and dilution, samples were divided into three sections, cooled to 4°C and stored for 68 hours. The first part was centrifuged and the supernatant was removed (Method I). The second section was centrifuged and the supernatant was mixed again (Method II). The third section was kept without change at 4°C (Method III). Samples were obtained from each method were divided into three equal parts, added 0, 10 and 20% of seminal plasma and incubated at 4°C. Sperm motility, viability, plasma membrane integrity, acrosome membrane integrity were evaluated after 4 hours. Sperm viability was higher in the presence of 0% seminal plasma (69/416%) than 20% seminal plasma (60/667%; P<0/05). The lowest sperm motility (11/667%), viability (59/167%) and plasma membrane integrity (48/168%) was observed in Method I (P<0/05). Methods did not affect the integrity of the acrosome membrane (P>0.05). Therefore, removing egg yolk and adding seminal plasma reduces coated sperm quality after 72 h storage.

The ecto-parasitic mite Varroa destructor is a serious world-wide pest of the honey bee Apis mellifera and has being linked with the death of millions of colonies, though its role is not completely destroyer of the colony. The aim of this study was to determine the seasonal infestation of bee colonies in Fars province to the Varroa mite is devastating the honey bee. Samples of adult bees and pupae were collected from 120 apiaries in the spring, summer, autumn and winter during 2012-2013. Samples were taken from 30 apiaries in each season. For determining of infestation of adult bees, infected samples put inside the glass containing 70% ethanol. For determining of infestation of larval stages and pupae, in appropriate time from the side of the hive frame, a piece with dimensions of 5 × 5cm apart and with the ice was transported to the laboratory. Lowest rate of varroasis spread was in spring (30%) and it increases in the following seasons respectively and the highest rate was occurred in winter (50%). During the year infestation was found 39.2% of the apiaries. No significant difference was observed between the infection rate in different seasons (P>0.05).

In this research for identification of polymorphism in leptin gene in sheep population of Moghani breed, 90 heads were randomly blooded. Genomic DNA was extracted from blood samples and a piece including 471 bp from the part of exon 3 leptin gene was amplified with using PCR-SSCP. Five banding patterns AA, AB, AC, BC and CC were obtained with frequencies of 0.2, 0.25, 0.3, 0.1 and 0.15 respectively. The frequencies of A, B and C alleles were calculated as 0.475, 0.175 and 0.35 respectively. The Chi-Square test showed no significant deviation (P>0.05) from Hardy-Weinberg equilibrium for this locus in studied population. AC genotype was associated with highest birth weight and weaning weight. 6 months weight (SW), average daily weight gain from weaning to six month, yearling weight estimated breeding value, weaning weight estimated maternal breeding value and 6 months weight estimated maternal breeding value were highest in the BC genotype. AA genotype was associated with highest average daily weight gain from six to nine month (AGSN). Birth weight estimated breeding value was most in the AB genotype. A selection at lower ages can be performed in Moghani sheep for leptin gene, because high genotypic and phenotypic correlations were observed between weaning weight and body weight at higher ages.

This experiment was conducted in order to evaluate the effects of dietary Aloe vera gel powder on performance, and humoral immunity of Japanese quails. Seven hundred one day old Japanese quails were allocated in a completely randomized design with 4 treatments replicated 5 times each with 35 birds per replicate. The experimental treatments were: 1) control group (basal diet, diet without aloe vera gel powder), 2) basal diet + 0.1 percent of aloe vera gel powder.3) basal diet + 0.2 percent of aloe vera gel powder, and 4) basal diet + 0.3 percent of aloe vera gel powder. The results did not show any significant differences between dietary treatments for feed intake, feed conversion ratio and weight gain (P>0.05). Statistically, a higher thymus weight (% of body weight) was found for group with 0.3% Aloe vera gel powder compared to the control group (P<0.05). The relative weights of spleen and bursa of fabricius and total immunoglobulin (Ig) and IgG antibody titers against SRBC were increased by increasing the levels of Aloe vera gel powder in the diets but these differences were not significant (P>0.05). The highest IgM antibody against Sheep Red Blood Cell (SRBC) was obtained by 0.3% Aloe vera gel powder group (P<0.05). In spite of non-effective impact of Aloe vera gel powder on the performance of the birds, the improved response of immune system found with this study could be beneficial for the quails in some stress conditions.

This study was conducted to evaluate the effects of germinated barley on the performance and egg quality of laying hens in different storage conditions. Six experimental diets consisted of Corn diet (corn basal diet), Barley diet (barley basal diet), Enzyme diet (barley basal diet plus enzyme Safizym) and 33, 66 and 100% germinated barley diets (in which barley was replaced by germinated barley at 33, 66 and 100 percent, respectively) were fed to laying hens for 10 weeks. Four replicates of 5 hens were allocated to each experimental diet. Results of experiment indicated, feed intake and feed conversion ratio were significantly for enzyme diet (124.09 gr and 2.13, respectively) and germinated barley 100% (125 gr and 2.04, respectively) than hens fed barley diet (129.68 gr and 2.28, respectively) (P<0.05). Egg weight in germinated barley 100% was significantly lower than barley diet (63.63 and 65.29gr, respectively), but egg production (95.97 and 87.61%, respectively) as well as egg mass production (61.08 and 57.67 gram per day, respectively) were higher (P<0.05). Storage of eggs resulted to significant (P<0.05) decrease of specific gravity (from1.087 to 1.066), albumin index (from 10.70 to 5.52), albumin percent (from 54.97 to 55.91), Haugh unit (from 90.47 to 68.03) and yolk index (from 42.90 to 38.12). Therefore, use of germinated barley in egg laying diets can improve hen performance and egg storage decreases egg quality.

In this experiment for evaluation the effects of different levels of Rosa canina L. fruit on performance, egg traits and blood parameters, total of 288 Hy-line (W36) laying hens from 35 to 46 weeks were allocated to the experimental units in a completely randomized design in 6 treatments with 4 replicates of 12 hens each replicate. The dietary levels of Rosa canina L. fruit included in the study were: 0, 1, 2, 3, 4, and 5 % of diets. The results showed that use of Rosa canina L. fruit up to 5% in diets improved the egg production, egg quality traits and blood parameters compared to the control group (P<0.05). The best performance, the lowest feed price for each kilogram of eggs, the best egg quality traits and the lowest amount of uric acid in blood were observed with 3% of Rosa canina L. fruit. The lowest amounts of hematocrit, hemoglobin and red blood cells were seen in diet with 5% of Rosa canina L. fruit. Whereas, the lowest percentage of heterophle and the lowest ratio of heterophle/lymphocyte were observed with 2% of Rosa canina L. fruit. The overall results indicated that in laying hens, 3% of Rosa canina L. fruit in contrast with other experimental groups, significantly improve performance, egg quality traits, blood parameters and feed price for each kilogram of eggs.

In order to study the effects of the Saccharomyces cerevisiae probiotic and organic acids on the performance, nutrient digestibility and gizzard and cecum pH of broiler chickens, 256 one day old Ross 308 chicks were used as a completely randomized design with 4 treatments and 4 replicates. The chickens were fed with a basal diet supplemented with one of the four additives including avilamycin antibiotic, Saccharomyces cerevisiae, an organic acids mixture or Saccharomyces cerevisiae plus organic acids. At 28 days of age, 2 birds per replicate were slaughtered and their ileal contents were collected. The results of the present study showed that administration of 10 mg/kg avilamycin antibiotic improved bird performance and nutrient ileal digestibility, compared to the diets containing 1.5% Saccharomyces cerevisiae, 0.15% organic acids or the mixture of the yeast and organic acids (P< 0.05). The experimental treatments containing yeast, organic acids or the mixture of organic acids and Saccharomyces cerevisiae yeast decreased gizzard and cecum pH (P< 0.05). The results of this study showed that the Saccharomyces cerevisiae yeast and the mixture of the organic acids couldnt act as a suitable substitute for the avilamycin effects on the performance of the broiler chickens and even using both the yeast and organic acids was not resulted in any additive effects on the performance traits of broiler chickens.