فصلنامه پژوهشهای تولیدات دامی
پیاپی 11 (بهار و تابستان 1394)

This experiment was conducted to measure chemical composition and metabolisable energy of germinated barley (GB) in broiler chickens. For this purpose, chemical composition of barley and GB was determined and then four experimental treatments consist of a barley basal diet and replacing 33, 66 and 100 percent of GB in the basal barley diet was prepared. Apparent metabolisable energy (AME) and nitrogen corrected apparent metabolizable energy (AMEn) was determined by total excreta collection and chromic oxide marker methods. Results indicated GB had higher gross energy (4132 vs 4065 kcal/kg) and crude protein (11.81 vs 10.78 percent) and lower β-glucan (1.053 vs 3.18 percent) than barley. Higher replacing GB in the barley basal diet led to increase of AME and AMEn in both of methods, but it was significant for marker chromic oxide method (P<0.05). The metabolisable energy for GB was determined by regression method. The AME value of GB by total excreta collection and chromic oxide methods was 3315.05 and 3107.95 kcal/kg, and the AMEn value for GB was 3304.63 and 3110.95 kcal/kg for those methods resppectively.

An experiment was conducted to investigate the effects of hydro alcoholic extract of Withania coagulans (WC) and 1, 25-dihydroxycholecalciferol on performance and bone strength of male broiler chickens. Diets were arranged factorially (2×3×2) consisted of a positive control with adequate Ca (10.4 g/kg diet) and nonphytate P (NPP; 5 g/kg diet) exceed the requirements suggested in the Ross 308 broiler nutrient specifications and a negative control diet with Ca (7.3 g/kg diet) and nonphytate P (NPP; 5 g/kg diet), three levels of WC (0, 100 and 200 mg/kg diet), and two levels of 1, 25-dihydroxycholecalciferol (0 and 0.5 μg/kg diet). Reducing the dietary Ca level by 30 % decreased tibia diameter (P<0.05) at 42 day of age. Bone fracture energy significantly increased with supplementation of 1, 25-dihydroxycholecalciferol at 42 day of age (P<0.01). Supplementation of 100 mg/kg WC significantly increased shear force (P<0.05) and fracture energy (P<0.01) at 42 day of age. At 21 day of age birds provided with 100 mg/kg of WC had a significant higher cortical thickness and tended to increase at 42 day. The results of this experiment indicated that supplementation of 100 mg/kg fruit hydro alcoholic extract of WC exhibit beneficial effects on bone characteristics without any adverse effects on productive performance.

This experiment was conducted to evaluate the effects of different levels of zinc on performance, egg quality traits and some blood parameters under normal rearing condition. Ninety six 70-weeks-old laying hens were used in a completely randomized design with 4 treatments, 4 replicates and 6 hens in each replicate in 10 week period. Treatments were 4 different levels of zinc (40, 70, 100, 130 mg zinc/kg diet) that was supplied in the form of zinc sulfate. Blood samples were collected through brachial vein at the end of experiments. Results of the experiment indicated that birds were fed on diets containing 130 mg zinc/kg diet and diets containing 40 mg zinc/kg diet showed the highest and the lowest hen-day egg production (P<0/05). Average egg weight was highest in 130 mg zinc/kg diet during the experiment (P<0/05). Increasing the level of zinc, reduced feed intake and improved feed conversion ratio (P<0/05). The treatment containing 100 mg zinc/kg diet showed the best Performance. Increase haugh unit, in hens fed 130 mg zinc/kg diet, was higher than the others treatments (P<0/05). Eggshell quality was significantly affected by treatments (P<0/05). The levels of glucose, cholesterol and LDL were significantly decreased in hens fed on diets containing 130 mg zinc/kg diet (P<0/05). Also with the increase of zinc, serum triglycerides decreased, so that treatment with 100 mg zinc/kg diet showed the lowest triglycerides concentration (P<0/05). The results of this experiment showed that increasing the level of zinc can improve performance and egg quality of layers.

This experiment was conducted in order to investigate the effect of black pepper, garlic and turmeric powders on performance and antibody titer against Newcastle virus of broiler chickens using 448 Cobb 500 one day broiler chickens including male and female with 8 treatments in a factorial arrangement (2×2×2). Experimental treatments consisted of T1 (as control), T2 (black pepper powder), T3 (turmeric powder), T4 (garlic powder), T5 (black pepper and turmeric powders), T6 (black pepper and garlic powders), T7 (turmeric and garlic powders), T8 (black pepper, garlic and turmeric powders). Each treatment had 4 replicates and 14 chickens per replicat. In this experiment, two blood samples were collected from each replicate at 28 day-old birds. One week later the same pieces of chickens were bled when they were 35 days old and the sample was sent to the laboratory in order to measure antibody titer against Newcastle virus. As the mean of Newcastle antibody titer before and after vaccination was compared, a significant difference between treatments was appeared when they feed additives separately. However no significant difference was revealed between treatments when the additives were added simultaneously. At the end of trial, two broiler̛s were slaughtered and spleen of chickens from each treatment were weighed. So, the results showed that there was a meaningful difference among treatments in spleen's relative weight when feeding additives individually. But in the case of feeding with all three additives simultaneously, there was a significant difference between treatment 8 and control group. Evaluation of the results for feeding intake during whole period indicated a meaningful difference between treatment 5 and treatment 7. No significant difference was observed between treatments for weight gain and conversion ratio during whole period of the experiment. So, the use of additives simultaneously can positively affect on both the relative weight of spleen and feed intake, but for Newcastle titer, the additives can improve Newcastle titer only before vaccination. Also consuming black pepper powder and turmeric powder separately after and before vaccination, influenced positively on Newcastle titer, but garlic powder had no effect in this case.

An experiment was conducted with 264 Cobb 500 day-old chicks in order to study the effect of different substitution levels of soybean meal (SBM) with extruded soybean (ESB) and vitamin E supplement on performance and carcass characteristics of broiler chicks. This study was conducted in a 4×2 factorial arrangement with 8 treatment and 3 replicates of 11 broiler chicks per each replicate in a completely randomized design. The experimental treatments were four substitution levels of SBM (0, 25, 50 and 75 percent) with ESB and two levels of vitamin E supplementation (42 and 75 IU/kg of diet). Results showed the effects of different substitution levels of SBM with ESB on production traits like feed intake, weight gain and feed conversion ratio as well as some carcass characteristics (breast muscle, thighs and liver as a percentage of live weight) was not significant. A significant interaction effect was found between levels of SBM substitution with ESB and vitamin E on weight gain at 42 days of age (P<0.05). Effects of substitution of SBM with ESB on percentage of pancreas weight was significant (P<0.05) as with increasing substitution levels the pancreas weight also increased. Effects of vitamin E on all the traits was significant (P<0.05) but carcass traits was not significantly affected by vitamin E levels (P>0.05).

This experiment was designed to determine the role of vitamin E and coenzyme Q10 antioxidant on immunity of broilers in cold stress conditions. For this purpose, 500 male chicks in a completely randomized design with 5 treatments, 5 replicates and 20 chicks in each replicate were tested in 25 experimental units. Treatments were: positive control (normal conditions growth without antioxidants), negative control (cold stress without antioxidants), vitamin E (150 mg/kg diet), Q10 (40 mg/kg diet) and E+Q10 (cold stress associated with antioxidants). Temperature was fixed at 15oC from day 15 until the end pf experimnt. Results showed that the relative weight of spleen decreased in cold stress condition and using of antioxidants improve its relative weight. The relative weight of bursa was increased in cold stress condition (p<0.01). There was no significant difference between treatments in white blood cell parameters, vaccines titer and injecting SRBC showed no significant differences between experimental groups (p>0.05). Results showed that coetaneous basophile Hypersensitivity response to phytohemaglutinin (p<0.01) and proliferation in vitro T cell-mediated immunity (p<0.05) were significant and the use of antioxidants under cold conditions improves cell-mediated immune response. The use of antioxidants especially Q10 under cold stress conditions decreased mortality. The use of antioxidants in cold stress condition improves cell-mediate immune system and decrease mortality.

The aim of this study was to survey the effects of different levels of Stevia alcoholic extract on performance and humoral immune system of broilers. Two hundred one-day chicks (Ross 308) were studied in a completely randomized design with 5 treatments, 4 replications and 10 chicks per replicate. The treatment groups received 0 (control), 0.5, 1, 1.5 and 2 mL/L of Stevia extract, in drinking water, during days 3 to 42. Daily feed intake, daily body weight gain, feed conversion ratio and carcass characteristics were measured. The birds were immunized by sheep red blood cell (SRBC) on days 12 and 29 of age and serum antibody levels produced in response to SRBC were measured on days 28, 35 and 42. Newcastle vaccine was given on days 1, 6, 18 and 29 to chicks and blood samples were collected at 42d. Antibody titer against Newcastle virus was determined by the HI method. Result indicated that Stevia alcoholic extract hadn’t any significant effect on performance (P>0.05). All experimental groups increased antibody titer against Newcastle virus (P<0.05). Consumption of 1.5 and 2 mL Stevia extract increased anti SRBC titers (P<0.05). It is concluded that Stevia alcoholic extract had no significant effect on performance, but improved humoral immunity of broilers.

To study the effect of two types of phytase supplementation in 3 levels on performance, blood parameter and nutrient digestibility of male broiler chickens fed diets containing 2 level of phosphourous in a completely randomized design (CRD) experiment with 2×2×3 factorial arrangement and 4 replicates per treatment, 400 Ross male broiler chicks in a 45 days period were evaluated. Treatments were 2 levels of phosphorous (100% of requirement and 80% of requirement), 2 type of phytase supplementation (Iranian and Imported one) and 3 levels of phytase supplementation (0, 500 and 750 FTU). The diet formulated based on 2007 ROSS manual company. Phytase supplementation improved feed intake, feed conversion ratio, phosphorous and fat digestibility during the whole brooding period (P<0.05). Moreover, phytase supplementation increased relative weight of heart, pancreases, breast, tight and spleen (P<0.05). However, increased diets phosphorous level caused increases in blood phosphorous and decreased in blood calcium, similarity decreases in amino acid and fat digestibility (P<0.05). The results suggested that no difference observed between enzyme types (Iranian vs. Foreign one). Otherwise, Phytase supplementation at level of 750 FTU improved performance, phosphorous and fat digestibility. In the other hand phytase supplementation coudn’t compensates low phosphorous treatment affection.

The objective of this research was to evaluate the effects of monensin (MON), thyme (THY) and cinnamon (CIN) essential oils on dry matter and crud protein degradability characteristics of cottonseed meal, barley grain and corn silage, nutrient digestibility, and some plasma metabolites in Holstein steers (540 ± 35 kg initial BW) fed high-concentrate diets. Four rumen fistulated Holstein steers were used in a 4×4 Latin square design with 21-d periods and 4 treatments: control (no additive), THY (thyme oil; 500 mg/kg DM), CIN (cinnamon oil; 500 mg/kg DM) and MO (monensin; 33 mg/kg DM). Steers were fed ad libitum a basal diet as TMR consisting of 30 percent forage and 70 percent concentrate. Apparent digestibilities of dry matter, crud protein, and acid detergent fiber were similar among treatments, except neutral detergent fiber (NDF) digestibility which was lower (P ≤ 0.05) in steers fed CIN compared to those fed the MON diet. The addition of essential oils (EO) and MON had no effect on DM degradability parameters of cottonseed meal, barley grain and corn silage. Crud protein degradability characteristics of barley grain and corn silage were not influenced by additive treatments. Similarly, supplementation with EO and MO had no effect on the NDF degradability of corn silage. For CP degradability of cottonseed meal, except rapidly degradable fraction (a) and effective rumen degradability of CP, which was similar among experimental treatments; Feeding EO decreased (P ≤ 0.05) the slowly degradable fraction (b) of CP. The degradation rate of CP (c) was significantly higher (P ≤ 0.05) with than without MON. Plasma concentrations of glucose, urea nitrogen and cholesterol were not affected by MON, THY or CIN supplementation; although Plasma concentration of triglyceride was significantly increased by adding CIN compared to MON and THY (P ≤ 0.05). Results of this research indicate that supplementing steers with THY and CIN (500 mg/kg DM) had limited effects on nutrient digestibility, rumen dry matter and crud protein degradation characteristics of feedstuff and plasma metabolite consentrations.

Present study was carried out to study the effect of growth stage on chemical composition and degradability parameters of DM, NDF and CP in bersim clover (Trifolium repens). Plant samples were collected and studied at 5 stages of vegetative growth stage (second week, fourth week, sixth week, eighth week, tenth week). Ruminal degradability of samples was determined by in situ technique using two ruminal cannulated zel rams. There were significant differences between mean amount of DM, NDF, Ash contents; and their degradability of NDF including rapid degradable portion (a), slow degradable portion (b), Constant rate of degradability (c) and Effective Rumen Degradable (ERD) in different growth stages (P<0.05). Results showed that by developing growth stages the mean amount of CP, EE contents and parameters of NDF degradability were decreased, however the mean amount of Ash and NDF were increased (P<0.01). With increase of growth stages, the mean amount values of rapid degradable portion (a), slow degradable portion (b), potentially degradable portion (a + b), and constant rate of degradability (c) related to NDF decreased but the mean amount values of non degradable portion increased.

Phenology is a broad science topic of Ecology. Study of phenology for regulating of animal grazing programs and determining of palatability and nutritive value of plant species at different stages of vital in range is important. This study was carried out to determine the chemical composition and nutritive value of Salsola vermicolata and Suaeda fruticosa that are halophyte plants, in three phenological stages (vegetative, flowering and seeding) were studied. After collecting the plants and mills, chemical composition were determined by standard method, organic matter digestibility (OMD) and metabolizable energy (ME) by in vitro gas production method. Results indicated there are significant changes in chemical composition of plants in different phenological stages (P<0.05). With advancing of growth stage, the crude protein (CP), ME and OMD contents and the rate of cell fibers was increased. The highest gas production volume in 96 hours, OMD and decreated ME had related to Salsola vermicolata in vegetative stage (P<0.05). Forage quality of Salsola vermicolata in vegetative stage was the best nutritive value in compare with other phonological stages of Salsola vermicolata and different phonological stages of Suaeda fruticosa. Results showed that progress of growth stage and increase of cell wall fractions contents is caused significant decrease in nutritive value. So, it is recommended Salsola vermicolata can be fed for animal in vegetative stage which has more optimum nutritive value.

This research was conducted to investigate the effects of feeding of barley grain (whole or cracked) combined with two different protein sources (urea or soybean meal) on nutrients digestibility and rumen parameters (pH and ammonia concentration). Four rumen fistultated Mehraban sheep was used that the mean body weight of sheep was 36.5±0.5 kg. The the experiment was conducted in change over design with four periods of 14 days (4 × 4). Four different experimental diets were; 1) whole barley grain (%70) with urea (T1), 2) cracked barley grain (%70) with urea (T2), 3) whole barley grain (%70) with soybean meal (T3) and 4) cracked barley grain (%70) with soybean meal (T4). DM, OM, and CP digestibility were not affected by treatments but digestibility of neutral detergent fiber (NDF) was affected by treatments with the highest value obtained for soybean fed animals (P<0.05). Although average rumen pH was not different among treatments, determined pH on 2 h after feeding was differed among treatments (P<0.05). Also, urea supplemented diets increased ammonia concentration compared to soybean meal fed diets. The rumen ammonia concentration for treatments T1 and T2 increased dramatically for both hours 2 and 3 after feeding. So, protein source supplementation has more effects on digestibility compared to processing methods and soybean meal showed greater digestibility compared to urea. More over cracking the barley did not affect nutrients digestibility and only showed some effects on rumen parameters.

The objective of the present study was to estimate genetic parameters and trends for average daily gains and Kleiber ratios in Moghani sheep. The included traits were average daily gain from birth to 3 months of age (ADG1), average daily gain from birth to 6 months of age (ADG2), average daily gain from 3 months to 6 months of age (ADG3), average daily gain from 3 months to 9 months of age (ADG4), average daily gain from 3 months to yearling (ADG5) and corresponding Kleiber ratios (KR1, KR2, KR3, KR4 and KR5, respectively). Different univariate and bivariate animal models with additive genetic, maternal genetic, maternal permanent environmental and residual effects were fitted to estimate genetic parameters for the traits. Genetic trends were obtained by regressing the means of predicted breeding values on year of birth for each trait. Direct heritability estimates for ADG1, ADG2, ADG3, ADG4, ADG5, KR1, KR2, KR3, KR4, and KR5 were 0.12, 0.16, 0.14, 0.28, 0.26, 0.11, 0.15, 0.15, 0.26 and 0.19, respectively. Estimates of direct genetic trends were positive for all average daily gains and Kleiber ratios in this study and all these estimates, except for KR5, were significant (P<0.01). The results of this study indicated that improvement of growth traits of Moghani sheep seems feasible in selection programs.

The objective of this study was detection of polymorphism in β-Lctoglobulin gene and its association with milk production traits in Mahabadi goats using PCR-SSCP method. For this purpose, blood samples were taken from 89 Mahabadi goat that reared in the farm of animal science department at Tehran university (Karaj). DNA was extracted from whole blood using optimized salting out method. Specific primers used for amplification of 177 bp fragment from then 7 β-Lactoglobulin gene. For identifying the polymorphism, PCR products were electrophoresed on polyacrylamide gel (SSCP method) and stained with silver nitrate method. Results indicated the different patterns, may be due to polymorphism in this fragment. The frequency of the six pattern were 7.14%, 10.71%, 13.09%, 33.33%, 9.52% and 26.19% respectively. The statistical analysis indicated that the effect of different patterns were significant on milk production and somatic cell count (p<0.01), but on fat and protein percentage had no significant effect.

Guilani sheep, with a population 900 thousand heads, produce 16% of meat and 5% of milk in this province. However, no estimation for genetic parameters of various traits in this breed has been provided up to now. The aim of this study was to estimate genetic parameters for body weight at birth (BW), three months of age (3MW), six months of age (6MW), average daily gain from birth to three months of age (ADG1) and average daily gain from three months to six months of age (ADG2). D ata were collected during 1994 to 2009 and animal model was used. The estimated heritability for BW, 3MW, 6MW, ADG1 and ADG2 were 0.20±0.045, 0.33±0.063, 0.38±0.075, 0.16±0.039 and 0.15±0.044, respectively. The estimated genetic and environmental correlations between traits ranged from 0.04 to 0.98 and 0.03 to 0.96, respectively.