مجله دانش و پژوهش علوم دامی
سال بیست و دوم شماره 1 (پیاپی 22، تابستان 1400)

This study was conducted to evaluate the quantity of egg, and some blood parameters on 128 laying hens at 46 weeks of age in a completely randomized design with four treatments and four replications in 12 weeks and each experimental unit contains 8 laying hens. Treatments include (1) Control diet without thyme and garlic, (2) Diet contain of thyme 0.5 percent with garlic 1 percent, (3) Diet contain of thyme 1% with garlic 1%, (4) Diet contain of thyme 1.5 percent with garlic 1 percent, in diets based on corn and soybean meal. Evaluated parameters include qualitative traits (egg weight, dense albumen height, shell percentage, and yolk height) and some blood parameters. Results of qualitative treatments showed that there experimental treatments showed significantly better albumen and yolk height than control group (P>0.05).Regarding the blood parameters of the treatments including 1 percent thyme for SOD, HDL there were significantly differences between treatments (P>0.01). There was a significant decrease in MDA between experimental treatments and it showed the lowest amount in the treatments including 1 percent of thyme (P>0.01). Results for egg quality showed there were significantly more albumen and yolk's height of experimental groups  versus control group (P > 0.05) Treatment containing the highest rate of thyme (1.5 percent) per 1 percent garlic had the lowest HDL and had significant superiority compared to other treatments (P>0.05)

This study was designed to investigate the effects of Nano-Selenium and Sodium Selenite on performance, carcass characteristics, Glutathione Peroxidase and Superoxide dismutase of Japanese quail under heat stress condition. In this investigation, 300 Japanese quail chicks were used and the chickens were raised to 21 days in the same condition. The experiment was performed in a randomized complete block design (RCBD) with 3 treatments and 5 replicates of 20 chicks per replicate. The chickens daily were included under heat stress condition for 8 h at 34± 0.5oC. The results showed that weight gain and feed intake of chicks fed diets with Selenium Nano particles compared to the other two groups was significant (p < 0.05) as well as the FCR between different groups was no significant difference (p>0.05). The all three different treatments showed no significant effect on carcass composition (p>0.05) and increase in use of Nano-Selenium was more tender than sodium Selenite group, but not significant. The results revealed that glutathione peroxidase and superoxide dismutase activity increased significantly in second experimental group using selenium (p < 0.05). In the present study, superoxide dismutase activity was significantly increased after adding 0.2 mg sodium selenite and nano-selenium (p < 0.05). The group of hemoglobin using selenium sources was significantly increased, but not significant increase in hematocrit. Results in this investigation revealed that Nano-Selenium is a better alternative compare to sodium Selenite.

The aim of the present study was to compare two different types of probiotics on Arian male broiler duodenum morphology and growth performance in starter phase. 378  one-d-old chickens were allocated in 3 experimental groups and 6 replicates with 21 broilers in each replicate for 21 days. Experimental treatments included 1) control diet  ,without probiotic. 2) birds supplemented with Bacillus subtilis based probiotic. Birds supplemented with lactic acid bacteria based probiotics. At the end of experiment growth performance include feed intake, growth and feed conversion rate were recorded, one birds from each replicate was slaughtered and 1 cm of midpoint of the duodenum was taken and sent to laboratory to be studied by light microscopy. In the current experiment, there were no significance differences between probiotic addition groups and control for growth performance. Duodenum villus height, width, crypt depth, villus height/crypt-depth and surface area were not affect by probiotic addition. According to result of this experiment Bacillus subtilis or lactic acid bacteria-based probiotic usage had no effect on growth performance and duodenum morphology by light microscopy study in the starter phase.

In order to determine the most economic energy level of broiler diets, an experiment was conducted for 42 days using ROSS 308 broiler chicks. In a completely randomized design arrangement, 400 one-day old broiler chicks  were randomly distributed to 5 treatments and 4 replications. Each replication (one pen) contained 21 birds. Treatments were diets with 5 different metabolizable energy including 2900, 2950, 3000, 3050 and 3100 Kcal/Kg. The performance traits were measured periodically and at the end of the experiment.  Duncan’s mean comparison test showed that there was no significant difference between treatments in terms of weight gain during the starter period, but chicks fed by diets with 3100 Kcal/Kg showed significantly more weight gain than the other treatments in the growing (11- 24 d) and finishing periods (p < 0.05). Despite the feed consumption which were no significant difference between treatments in all of periods in the experiment, the feed conversion ratio of birds fed diets with 3100 Kcal/Kg was significantly less compared with the other treatments (p < 0.05). Results of carcass traits showed birds fed diets with 3100 Kcal/Kg had more breast efficiency than the other treatments.

This study was conducted to determine the effects of adding spent wheat straw compost from Agaricus bisporus mushroom in fattening calves diet. Spent compost was provided from a mushroom production farm and the remaining particles were separated from the straw after mushroom cultivation. Spent straw compost was sun dried and chemical composition analyzed for DM, OM, CP, CF, NDF, ADF, Ca and P. Fifty male Holstein calves with initial average weight of 321± 18 kg were randomly divided into experimental and control groups. Diets were adjusted based on the average weight of the calves and NRC recommendation. Spent straw compost was used in the experimental group at 10% of the diet. The experimental period was 180 days. The animals were fed three times daily with total mixed ration offered ad libitum. Feed intake, body weight changes, feed conversion ratio and feed cost per kg bodyweight were determined and compared. Results showed that feeding spent straw compost did not have any significant effects on daily weight gain, feed intake and feed conversion ratio of feedlot calves. Average daily gain in the control and experimental groups were 1204 and 1150 g, respectively. Average daily feed intake was 9.8 and 10.1 in control and experimental group respectively and feed conversion ratio of control and experimental group were 8.2 and 8.8 respectively. The use of spent compost slightly increased the cost of the diet as well as feed prices per kg increase in live weight in the experimental group. According to the findings of the present study, compost straw can be include up to 10 percent of the TMR form diet of finishing calves, but its economic advantage is dependent on access and cost.

The major histocompatibility complex (MHC) genes are very important in horse breeding according to relationship with immunity response and resistance or susceptibility to disease. The aim of this research is study of polymorphism possible in exon gene region and population genetics. To do this, 120 horses were selected randomly from Thoroughbred, Oldenburg, Caspian pony and Arab breeds. Genomic DNA was extracted via blood samples and polymerase chain reaction was done for a 309 bp MHC gene region. The PCR products were digested by RsaI restriction endonuclease for genotyping determination. Results show that there were three allele of A, B and C and six types of genotype of AA, AB, AC, BB, BC and CC with 0.3208, 0.3208 and 0.3584 allele frequency and 0.05, 0.25, 0.2917, 0.1333, 0.125 and 0.15 genotype frequency in all studied samples respectively. The most and least allele frequency in Thoroughbred, Oldenburg, Caspian pony and Arab are related to B, A, A, C and A, B, B, A alleles respectively. The Hardy-Weinberg equilibrium study by X2 and G2 tests shows the equilibrium situation in Oldenburg and Caspian pony breeds and non-equilibrium situation in Thoroughbred and Arab breeds. The overall results shows that the genetic diversity in studied samples can be used as a resource for horse breeding programs.