فصلنامه تحقیقات تولیدات دامی
سال هشتم شماره 2 (تابستان 1398)

In this study, 600 one-day Japanese quails were assigned to six treatments with five replicates of 20 chicks per replicate in 2×3 factorial arrangement based on a completely randomized experimental design. Two levels of L- arginine (the recommended level of NRC and 10% higher than the recommended level by NRC) and three levels of Guanidino acetic acid (GAA) (0, 0.6 and 1.2 g/kg diet) were used in this study. Body weight and feed intake were recorded at the end of the experiment. On day 42, blood samples from two chicks of each replicate were taken from wing vein for some blood metabolites measurements. Then, thechicks wereslaughtered for carcass and internal organs investigations. L-arginine supply at 10% over NRC recommendation increased daily feed intake, and improved body weight gain and feed conversion ratio significantly (P<0.05). L-arginine supply at 10% over NRC recommendation and 1.2 g GAA/kg diet increased feed intake and improved feed conversion ratio (P<0.05). The relative weight of breast and thigh increased and abdominal fat decreased significantly by L-arginine supplementation (P<0.05). The main effects of L- arginine and GAA on blood metabolites were significant (P<0.05), with a reduction effect on cholesterol, triglyceride and VLDL concentrations and enhancement effect on HDL content. L-arginine supply at 10% over NRC recommendation with 0.6 and 1.2 g GAA/kg diet significantly decreased blood cholesterol, triglyceride and VLDL and increased HDL concentrations in compared to those fed L- arginine at NRC recommendation (P<0.05). Therefore, the findings of this study showed that providing extra L- arginine than the NRC recommendation with 0.6 g GAA/kg diet significantly improved performance and decreased blood serum cholesterol, triglyceride, and VLDL in Japanese quails (P<0.05).

The presence of vitamin D3 in eggs is important for calcium metabolism of embryo and its development. This research was conducted to evaluate the effect of dietary vitamin D3 levels of 0, 1000, 2000, 4000 and 8000 IU/Kg on reproductive characteristics of Japanese quail. 320 adult Japanese quails were used in a randomized complete block design with five treatments, four replicates containing 12 females and four male birds in each replicate. After six weeks of feeding with experimental diets, 40 eggs from each replicate were transferred to a hatchery machine. After incubation, reproductive parameters were investigated. On day 42 of the experiment, two male and female birds from each replicate were selected to measure the blood sere testosterone and estrogen levels. Fertility, total hatch and weight of hatching chicks were not affected by vitamin D3 (P>0.05). The lowest (79.75%) and the highest (90.53%) hatch of fertile eggs were recorded in diets without vitamin and containing 1000 IU/Kg of vitamin, respectively (P<0.05). The highest early and total embryonic mortality were related to zero level of vitamin and the lowest losses were belonged to 1000 IU/Kg of vitamin. The mid and late embryonic mortalities were not influenced by treatments (P>0.05). The morphometric characteristics of reproductive system in both sexes and blood sera estrogen level in female birds were not differ (P>0.05). The highest sera testosterone concentration (11.05 ng/ml) was observed in 1000 IU/Kg of vitamin (P<0.05). In conclusion, the use of 1000 IU/Kg of vitamin D3 in Japanese quail diet is recommended for the best reproductive performance.

This study was conducted to evaluate the effects of different selenium sources plus vitamin E on the quality of Japanese quail eggs. The birds were fed the diets for 56 d.  At the end of feeding period, the eggs were collected and stored for 15 or 30 d at 5°C or 22°C before quality measurement. A completely randomized experimental design in factorial arrangement 2 × 3, with four replicates and 24 eggs each was applied. The dietary treatments included three diet types (basal diet, basal diet plus 0.4 mg sodium selenite and 120 mg/kg vitamin E and basal diet plus 0.4 mg sel-plex and 120 mg/kg vitamin E) and two different storage temperatures (5°C or 22°C). The quality measurements included egg weight loss, albumen height, albumen pH, Haugh unit (HU), yolk index, yolk pH and malondialdehyde (MDA) concentration. Organic and inorganic sources of selenium plus vitamin E supplementation significantly decreased the percentage of egg weight loss but increased height albumen, HU and yolk color of egg compared to control group (P

The present study was carried out to investigatethe effects of different forms of zinc (no zinc, ZnO  and Zn-Met) and butyric acid on internal eggquality traits and performance in Hy-Line W36 strain laying hens using 144chickens from 74 to 83 weeks of age in the second phase of laying. A completerandomized block design with 3 × 2 factorial arrangement with six treatments, sixreplicates and four layers per replicate for nine weeks was used. Performanceparameters were measured daily and quality traits were measured in threeperiods of age. The results of the experiment showed that the main effects oforganic acid and three forms of zinc on egg production, defective eggs, eggweight, egg mass, feed conversion ratio and daily feed intake were notsignificant during the whole experiment. During the period of 74 to 77 weeks,feed conversion ratio for the treatment containing mineral zinc and organicacid was higher than other treatments (P

Energy of inputs is a necessityof life for human beings all over the world due to its function instrengthening the security and contentment of the people. This study was focused on economics of energy onlaying hen rearing units in Iran. The data of this study obtainedfrom a sample of 354 farms that were taken from an industrial farm censusconducted by the Statistical Center of Iran in 2016. Investigation of energy efficiency in the layinghen rearing industry indicated that index of energy productivity in the firstgroup (the provinces of East Azarbaijan, West Azarbaijan and Hamadan) and thesecond group (the provinces of Tehran, Qom and Markazi) are 47 and 48 kg/MJ and specific energy ratios for these two groups were 40.74 and 29.96 MJ,respectively. Result of this study showed that energy efficiency was low and energy perishes was high in this industry. Therefore, modern and wellestablished scientific practices can be used to improve energy efficiencyand reduce energy losses.

Baluchi sheep is one ofthe indigenous sheep breeds originating from the eastern part of Iran and it isadapted to the severe weather conditions. The economic efficiency of sheepbreeding is clearly related to the reproduction efficiency of the ewes. In thisstudy, twinning trait was studied as an important reproductive trait. Toidentify the genes associated with twinning trait, genome-wide association wasdone using 91 Baluchi ewes genotyped with 50k Illumina SNP chips. For thispurpose, the extended repeatability model was used. In the next step, a geneset enrichment analysis was implemented to identify the biological pathwaysassociated with the twinning. Six SNP markers on chromosomes 1, 3, 10, 15 and25 located in CTH, ANKRD13C, SRSF11, PTGER3, LDHB, LRRC40, and KCNMA1 geneswere identified. According to pathway analysis, 25 pathways were associatedwith the twinning trait. Among those pathways, the defense response biologicalpathway has an important role in the ovulation. Interferons and interleukinsare the main cytokine proteins in this pathway. These cytokines create aprocess such as inflammation that causes oocytes releasefrom the follicle into the oviductfor transport and fertilization. Cell adhesion andintercellular bridge pathways were other significant pathways. Cell junction pathwayvia the CX43 protein can affect the transfer of GDF9 effects togranulosa cells. To the best of our knowledge, this is the first study thatreports indirect effects of GDF9 on twinning trait in Iranian sheep.

In this study the possibility of producing a new compound to prevent ruminal acidosis were studied using common buffers, minerals and herbs, based on parameters such as: ability to maintain pH, acidogenic value (AV), amount of in vitro dry matter disappearance (IVDMD) and the AV/INVDMD ratio in high-concentrate diet in an in vitro batch culture. This study performed in a completely randomized design with four experiments. In the first experiment, the treatments were the buffers (sodium bicarbonate, potassium bicarbonate, magnesium oxide, sodium bentonite and zeolite) in the level of 1% DM of the ration, and the herbs (anise, rosemary, pepper, marjoram, cinnamon and garlic) in the level of 1% DM of the ration and minerals (cobalt, copper, manganese, selenium and zinc) used in one part per million units of the diet. In the second and third experiments, the treatments were the various components of buffers, herbs and minerals, in the level of 1% DM of the ration. The compound 1 (29.5% sodium bicarbonate, 25% magnesium oxide, 18% sodium bentonite, 10% anise, 9% garlic  and 8.5% rosemary) had a significant effect on performance in the third experiment which was named "Rumenobuffer". In the fourth experiment, the Rumenobuffer was tested in comparison with sodium bicarbonate and rosemary. The results of the first experiment indicated that sodium bicarbonate, potassium bicarbonate, magnesium oxide and rosemary had significant effects on pH, acidogenic value and IVDMD compared to other treatments (P

Insulin and glucagon are glucoregulatory hormones which their secretions are critical for glucose hemostasis during inflammations. Intra-mammary LPS (lipopolysaccharide) challenge causes an immune reaction which is accompanied by metabolic and endocrine changes. The objective of the present study was to investigate the effects of intra-mammary LPS challenge concomitantly with elevated insulin concentrations on glucagon concentration during simultaneous hypoglycemia or euglycemia in dairy cows. Nineteen Holstein dairy cows with body weight of 3.0 ± 0.1 (mean ± SD) were randomly assigned to three treatment groups: an intravenous insulin infusion (Hypoglycemia; HypoG, n=5), insulin and glucose infusion (EuG, n=6), and a 0.9 % saline solution infusion (Control, n=8). At 48 h of metabolites infusions, LPS injected to two quarters of mammary glands. In response to LPS challenge, plasma insulin and glucose concentration increased. Intra-mammary LPS challenge caused an increase in plasma glucagon concentrations in HypoG and control compared to EuG group, pre infusion level, and pre LPS challenge. In conclusion, intra-mammary LPS challenge induced increases of glucose, insulin, and glucagon concentrations. The results showed that glucagon concentrations increased during immune system stimulation despite the increase of insulin concentrations, and its role is important in glucose metabolism hemostasis during inflammation.