مجله علوم دامی ایران
سال پنجاه و یکم شماره 2 (تابستان 1399)

This study was designed to evaluate the effects of encapsulated reduced glutathione added to extender on the quality of bull sperm after freezing and thawing process. Extender contains lecithin nanoliposomes supplemented with different concentrations of glutathione (0, 1, 2.5 and 5 Mm concentration). The supplemented nanoliposomes with glutathione were prepared by thin-film preparation method.  The particle size decreased to nanometer by sonication. 40 ejaculations were collected from 6 Holstein bulls and frozen for 6 weeks. Evaluated characteristics after freezing and thawing process were kinetic parameters (CASA), membrane activity (HOST), membrane integrity (eosin-nigrosin) and morphology of sperm ( Hancock's solution). Results showed that level 1 mM significantly increased the total and progressive motility (47.5±1.7, 32.7±2 %).  Although, there was no significant difference with level 2.5 mM glutathione (45.0±1.7, 26.2±2 %). Also, the concentration of 2.5 mM showed the highest value of cell membrane integrity and cell membrane functionality but did not differ with the concentration of 1mM. However, supplementation of nanoliposomes with 5 mM glutathione reduced the quality of post-thaw sperm. Thus, level 1 M encapsulated glutathione can provide better protection compare to the other level of that for bull sperm.

A 360 Ross 308 broilers were used in a completely randomized design with 6 treatments and 4 replicates with the objective of comparing the effects of different sources of zinc on growth performance and some liver enzymes. The experimental treatments were: 1) negative control (non-supplemented), 2) positive control with 80mg/kg zinc sulfate, 3) hydroxychloride Zn (80mg/kg), 4) zinc sulfate (60mg/kg) + Zn-Met (20mg/kg), 5) zinc sulfate (40mg/kg) + zinc oxide (40mg/kg) and 6) zinc sulfate (30mg/kg) + zinc oxide (30mg/kg) + Zn-Met (20mg/kg). After 42 days, relative weight of bursa of Fabricius  (except for treatment 4) and thymus (except for treatment 3) were decreased significantly compared with the  negative control group (P<0.05). The hydroxychloride Zn source improved feed intake, compared to positive control group and daily weight gain compared to treatments 1, 2 and 4 (P<0.05). The inclusion of zinc oxide in treatments 5 and 6 increased alkaline phosphatase activity in plasma compared to treatments 3 and 4 (P<0.05). But, there were no differences in plasma AST, ALT, and LDH levels among the zinc different sources. These findings show that hydroxychloride Zn have comparable effects with zinc of inorganic and combination of organic with inorganic sources in broiler chickens.

The present study was performed to identify the copy number variations and their impacts on the genes of dromedary camels using whole genome sequencing data of two Iranian dromedary camels (Yazdi camel and Trodi camel). Whole genome sequencing of the Yazdi and Trodi samples produced about 456 and 418.8 paired-end reads with a read length of 100 bp, respectively. After mapping of trimmed reads to reference genome (NCBI accession number: GCA_000767585.1), a read-depth based algorithm was used to identify copy number variations. Identified copy number variations of studied samples, were 831 for Yazdi and 312 for Trodi camels. Nearly 60% (606 genes for Yazdi and 288 for Trodi camel) of the identified variants overlapped with the genes, and the rest were in the none genic regions. The obtained results showed that important genes including genes involved in immune system function and programmed cell death have copy number variation. As well as, two important genes of studied samples, OOEP and WWC3, which are involved in mammalian reproductive function, had copy number variation.

In order to investigate the changes of IGF-I gene transcription during the sexual maturity period of Fars native roosters, 24 roosters in the age of 5, 6, 7, and 8 months were selected randomly. In each date of sampling 6 roosters were slaughtered and testes were collected for evaluation the level of IGF-I gene transcription. The results indicated that IGF-I gene transcription in the testes of 6, 7 and 8-month roosters were increased compared to 5-month roosters while the expression of this gene did not change in 7th months compared to 6th months. The results also indicated that the level of IGF-I gene transcription did not differ significantly in left and right testes in all ages (5th-8th months) but the left and right testes weight increased in 7th and 8th months compared to 5th and 6th months. The maximum and the minimum rates of left testis length to its width were observed in 6th and 8th months respectively but this rate did not change in right testis among different ages. Histological investigation also indicated that the maximum number of Sertoli and Leydig cells in both left and right testes was observed on 8th months. In conclusion the results indicated that the gene transcription of IGF-I had an increasing procedure during the sexual maturity period of roosters (5th-8th months) and weight of the left and right testes reached to their maximum rate in 7th and 8th months.

In this research the effects of different levels and particle sizes of zinc oxide on reproductive performance of hens and roosters of broiler breeders were evaluated. A total of 200 female Ross 308 broiler breeders in a completely randomized design with 4 treatments, 5 replicates and 5 birds per each replication, and 24 male Ross 308 broiler breeders in a completely randomized design with 4 treatments, 6 replicates and one bird per each replication at 54 weeks of age were used. The experimental treatments included the diets containing 70 mg zinc from zinc oxide with large particle size (LPZnO-70), 100 mg zinc from zinc oxide with large particle size (LPZnO-100), 70 mg zinc from zinc oxide with small particle size (SPZnO-70) and 100 mg zinc from zinc oxide with small particle size (SPZnO-100). The results indicated that the experimental treatments had no significant effect on egg production, body weight, egg weight and egg yolk weight. In the entire experimental period, the egg shell thickness was significantly higher in treatment containing SPZnO than LPZnO (P<0.001). The highest and lowest fertility and hatchability ratioes were observed in treatments containing SPZnO-100and LPZnO-70, respectively. The highest semen volume was observed in roosters of treatments containing SPZnO-100 and LPZnO-100 (P< 0.05). Generally, it can be concluded that SPZnO has a more desirable effect on reproductive parameters of broiler breeders due to its higher bioavailability. Since the level of 100 mg zinc per kg of diet from both sources of zinc oxide resulted in better reproductive performance, the utilization of SPZnO-100 might be recommended.

This study was conducted to investigate the effects of Halocnemum strobilaceum and Suaeda aegyptiaca halophytes plants feeding on performance, feed digestibility, blood parameters and carcass characteristics of lambs fed by high-concentrate diets. Thirty six Arabian male lambs with an average age of 4.5±0.2 month and 25.3±1.13 kg live weight were fed by experimental diets for 80 days. The experimental diets included 1- Control, 2- 15% Suaeda, 3- 15% Halocnemum, and 4- 30% mixture of Suaeda and Halocnemum. Treatments had no significant effects on daily weight gain, feed conversion ratio and final body weight. Water intake increased by consumption of halophytes (p < 0.001) compared to the control group. Crude fat and ADF digestibility were higher in control and 15% Suaeda treatments compared to other treatments (P=0.003). Organic matter digestibility was higher in 15% Suaeda and 15% Halocnemum treatments compared to other treatments. Blood urea nitrogen of lambs fed by 30% mixture of Suaeda and Halocnemum was lower than other treatments (P=0.0001). Lambs fed 30% saline plants had less total deposit carcass fat (P=0.024) and more meat content (P=0.006). Muscle yellowness increased in lambs fed halophytes compared to the control treatment (p < 0.001). The results of this study showed that replacement of wheat straw and alfalfa hay with Halocnemum and Suaeda, in high concentrate diets could maintain fattening performance and reduce carcass deposition of fat.

This study was conducted to evaluate the effect of corn particle size and different insoluble fiber sources on performance and carcass and gastrointestinal tract characteristics of broilers from 1 to 21 days of age. A total of 660 male broilers were used in a 2×3 factorial arrangement with 6 treatments and five replicates per treatment. The factors of interest were two corn particle sizes (2 and 6 mm) and three insoluble fiber sources (lignocellulose, rice hull, RH and sunflower hull, SFH). The main effect of fiber source was significant for the body weight gain (P<0.01) and feed conversion ratio, with SFH inclusion improved BWG (P<0.01) and FCR (P<0.01) compared to OH and lignocellulose. The supplementation of lignocellulose (P<0.05) and fine particles (P<0.01) resulted in higher carcass weight compared to other fiber sources and coarse particles, respectively. Feeding lignocellulose increased (P<0.01) the weight of the small intestine than the other two fiber sources. The Experimental treatments had no significant effect on the relative length of small intestinal segments. Coarse grinding of corn and SFH inclusion reduced gizzard pH when compared to fine grinding and lignocellulose inclusion, respectively (P<0.05). The Gizzard weight of birds fed a diet containing lignocellulose and SFH was significantly higher (P<0.01) those fed RH. Generally, the dietary inclusion of 3% SFH improves growth performance through improved weight and reduced pH of gizzard and can be practically used in the broiler industry.

This study was conducted to evaluate prevalence of BVD and the strategies which were applied for prevention of BVD over the past 50 years in some provinces of Iran. Blood samples of 500 Iranian Holstein race were randomly collected from three dairy farms located in Tehran, Isfahan and Qazvin provinces. BVD control protocols of these farms were recorded. ELISA technique was used to measure the antibody and antigen titers for BVD. RT-PCR technique was performed to investigate the presence and the type of virus in all samples. The prevalence of Ab-/ Ag-, Ab+/ Ag-, Ab-/ Ag+ and Ab-/ Ag+ were 10.2%, 78.8%, 7.2% and 3.8%, respectively. Furthermore, approximately 4.2% of the animals were PI and the prevalence of antibody and antigen titers had not significant difference in three provinces. All positive samples were BVDV type 1. Type 2 was not observed in this study. The results of the study indicated that the efficiency of the used protocols to control BVD diseases is not successful. So, to control the BVD, applying large management policies at the national level is fundamental beside the biosecurity strategies.