فصلنامه پژوهشهای علوم دامی ایران
سال پنجم شماره 3 (پاییز 1392)

An experiment was conducted to evaluate the effect of chemical amendments and reused litter on broiler performances، immune response and skin quality. Five hundred and seventy six (576) day old broiler chickens were randomly allocated to 3x2 factorial design experiment. Three amendments treatment included control (no chemical addition)، alunminum sulfate and zeolite; two types of litter were new and reused one. There were 4 replicates and 24 broiler chickens in each pen. The feed and water were available ad libitum during 42 days of experiment. The type of bedding had no significant effect on broilers performances (weight gain، feed efficiency ratio and mortality). Chemical amendments improved broilers performances during 0-35 days of production period but by the end of experiment there was no differences between treatment groups. Neither bedding type nor chemical amendments influenced skin erosion criteria responses. The immune response of broilers was not affected by either type of bedding or chemical amendments. It could be concluded that although beddings to be reused، it should be treated so as to overcome any defect of reused bedding.

An experiment was conducted to study the effects of dietary levels of extruded full fat soybean (EFFSB) on performance، blood metabolites and intestinal morphology of broiler chickens. A batch of FFSB was wet extruded at 155 °C، 15 seconds to provide the extruded full fat soybean (EFFSB) sample. One hundred and forty four d-old Ross 308 male broiler chicks were divided into 12 groups with 12 birds each and assigned to starter، grower and finisher diets each containing 0، 7. 5 and 15 % of EFFSB. Feed intake of chicks fed diet containing 15% EFFSB، were significantly reduced as compared to those fed the control diet during 1-14 d of age، but were not influenced during grower، finisher and the whole experimental period. A significant linear decrease was observed in weight gain of birds during whole period. Relative weight of pancreas، aspartate aminotransferase، alanine amino transferase، lactate dehydrogenase، and creatine kinase (CK) in blood serum of chicks were not influenced with dietary EFFSB level. A significant linear decrease was observed in serum triglyceride and total cholesterol with increasing in dietary levels of EFFSB at 42 d of age. The villi length decreased linearly with increasing dietary levels of EFFSB in duodenum section of small intestine، causing a significant decrease in villi surface area in duodenum of birds fed 15% EFFSB diet as comparing to control birds، the crypt depth and villus length/ crypt depth were changed. The morphological measurements of small intestine mucosa in jejunum and ileum sections were not significantly influenced by dietary EFFSB at 42 d chickens. It is concluded that using full fat soybean extruded at 155 °C up to 15 % of diet did not influence significantly performance of chickens during whole period، although the villi length and villi surface area decreased in duodenum of birds with increase in the usage of EFFSB.

In this study، we determined the effects of replacing different levels of alfalfa with Pistachio Hull (PH) on feed intake، digestibility of nutrients، rumen fermentative parameters، blood metabolites and nitrogen metabolism in Balochi male lambs. Three male lambs (35±2 kg live weight) equipped with ruminal and abomasual cannulas were randomly assigned into a 3 × 3 Latin square design. Experimental diets included 1) 30% alfalfa، 20% wheat straw، 50% concentrate (DM basis) and in 2 and 3 diets the 15 and 30% of alfalfa was replaced with Pistachio Hull، respectively. Result showed that feed intake was not different between treatments. Total tract digestibility for DM، OM، ADF and NDF were not significantly affected by the diets، but CP in total tract was significantly decreased. Dietary PH content resulted in a decrease in the rumen N-NH3 concentration. The concentration of liver enzymes، cholesterol، HDL، LDL and VLDL were not influenced by PH content of diet. As tannin was increased in the diets، the nitrogen intake، nitrogen excretion from urine and digested nitrogen significantly were decreased. Nitrogen excretions from fecal were significantly increased by increased of dietary tannin. Therefore، using of PH in level of 30% (DM basis) due to supply appropriate levels of tannin without negative effects on feed intake and nutrient digestibility، can improve animal performance and with increasing nitrogen excretion from urine to feces environmentally can be very beneficial.

In this experiment، fermentation parameters of a TMR ration determined with different levels of phosalone as an organophosphate pesticide (0، 100، 250، 500، 750 and 1000 ppm) and bentonite (0، 1 and 2 %DM of TMR) using in vitro batch culture and gas production techniques. The results from gas production showed that cumulative gas production for 96h after incubation significantly decreased with increasing the levels of phosalone and lowest gas production for this time was observed at 1000 ppm of phosalone. Increasing phosalone in the culture was accompanied with deceasing DM degradability and NH3-N and differences between treatments were statistically significant، so that phosalone at 1000 ppm and control groups had lowest and highest NH3-N respectively. With increasing of phosalone at different levels to the medium، pH remained constant during the 24h incubation، but with increasing the levels of bentonite (specially the 2 percent level)، the pH relatively increased. The results of this experiment showed that some of fermentation parameters (such as cumulative gas production at different incubation times، NH3-N and DM degradability) decreased by increasing phosalone in culture media (0 to 1000 ppm). Supplementation of bentonite rather than the control group with no pesticide resulted to decreasing of the gas production at 96 h incubation. In coordination with these results، generally supplementation of bentonite (especially at 2% of DM) to different level of phosalone also resulted to decreasing of the cumulative gas production in different times of incubation. There was no significant effect for DM degradability by adding the bentonite to culture media between treatments، although only by adding the bentonite at 1000 ppm phosalone، DM degradability increased.

This study was conducted to determine the chemical composition and degradability characteristics of a pasture plant Salsola tomentosa by nylon bags method. The sampling was performed from the northern region of plain''s Gonabad city in three growth stages (vegetative، flowering and seeding). The samples dried in air، were milled and their chemical composition were determined. To determine the degradability of dry matter، protein، acid detergent fiber and neutral detergent fiber، two fistulated cows were used and degradation of samples were measured and calculated at 0، 2، 4، 8، 16، 24، 36، 48، 72 and 96 h. The results of this study showed that the highest of protein and organic matter percentage were 10. 34% and 76. 75% respectively in vegetative stage and there was statistically difference between growth difference stages. The highest amount of ash was observed in seeding stage (31. 9%). Advancing growth stage was associated with decreasing plant protein and increasing acid detergent fiber (ADF) and neutral detergent fiber (NDF). Dagradability of dry matter، crude protein، ADF and NDF were greater in vegetative stage as compared with other stages. Degradabilities of NDF،ADF and CP were decreased significantly as growth increased. The results of this study showed that with advancing of growth stage، concentration of CP decreased، and fiber content increased and degradabilities of CP، NDF and ADF were decreased significantly as growth increased

The aim of this research was to study the Effect of reduction in dietary protein on fertility performance of lactating Holstein cows during heat stress. For this we used 63 Holstein dairy cows (71 ± 16. 5 DIM) after voluntary waiting period and has been confirmed that the health reproduction based on randomized complete block design. Randomly، cows enrolled to the one of three experimental rations (18. 5، 17. 5، 16. 5% CP). All cows were inseminated according to Heat-Synch protocol. Ovarian structure was defined by ultrasound twice in protocol. The number of small (< 5 mm)، medium 2 (5 to 9. 9 mm)، and large (> 10 mm) follicles were counted by ultrasonography. Cumulative conception rate to first and second service was 47. 7، 52. 4 and 76. 2 % for treatments 1، 2 and 3 respectively. Numbers of Service per conception were 2. 07، 2. 03 and 1. 53. Days open 131. 7±26، 132. 5±18 and 121. 16±22 d for treatments 1، 2 and 3 respectively. In conclusion increase in the level of crude protein of diet above recommended NRC (2001) because of increase in blood urea nitrogen and harmful effects on uterine health and decrease in fertility during heat stress not recommended.

The aim of this experiment was to compare the population and morphology of ruminal protozoa of Holstein and Khuzestan water buffalo steers fed with the same diet. Rumen fluid collected from cow and buffaloes (12 head) that were fed with the same diet، 30:70 concentrate: forage. The collected samples were fixed by formaldehyde 18. 5%، and ciliates were counted and their genus and species were determined. The results of this experiment showed، total rumen protozoal number of khuzestani water buffalo was higher than the cattle (3. 68×105 vs. 2. 18×105/ mL of rumen content، respectively). The genus of Diplodinium، Entodinium، Epidinium، Ophryoscolex and Holotriches of cow and water buffalo was 37. 63، 48. 77، 0، 3. 75، 9. 83 and 44. 47، 42. 35، 5. 31، 0. 68، 7. 18 %، respectively. There was no species from Epidinium genus (Epidinium ecaudatum and Epidinium cudatum) and Diplodinium cristagalli species in the rumen of cattle، but they found in the rumen of khuzestani water Buffalo. Also it was identified that there was Ophryoscolex purkynei in both rumen cattle and water buffalo، but in the rumen of cattle was higher in comparison to the buffalos. Therefore، it appears under the same diet، there is a significant difference in total rumen protozoal number and species of Holstein cow and Khuzestani water buffalo.

Foot-and-mouth disease (FMD) is a severely contagious viral disease in cloven-hooved animals that it causes considerable economic losses in livestock productivity. Vaccination is one of the most effective procedures for control of FMD. One of vaccines performances is stimulating expression of some immune system genes، which called cytokines. In this study، expression changes of IFN-γ and TGFβ1 genes were evaluated in vaccinated guinea pigs with FMD type O inactivated vaccine. Blood samples were collected from vaccinated and control (no vaccinated) guinea pigs in three distinct times. After blood sampling، RNA was extracted and converted to cDNA. For measuring IFN-γ and TGFβ1 genes expression، relative Real-time PCR procedure was used. The results showed that expression of IFN-γ and TGFβ1 genes in the second and third blood sampling were significantly increased in comparison to the first blood sampling. Because increasing of cytokines expression is an indicative of the immune system response، these genes can be used as indicators for testing effects of the recombinant vaccines.

Embryonic stem cells (ESCs) are derived from the inner cell mass (ICM) of blastocyst and differentiate into all three embryonic germ layers: ectoderm، endoderm، and mesoderm. In this study، ESCs are derived from Hand Made Cloning (HMG) blastocysts and their efficiencies compared to ESCs derived from In Vitro Fertilization (IVF) embryos. Feeder layer was used for ESCs culture، and culture medium consisting of Knockout- Dulbecco’s Modified Eagle’s Medium (Ko-DMEM) supplemented with Knockout Serum Replacement (KSR)، Leukemia Inhibitory Factor (LIF)، Basic Fibroblast Growth Factor-2 (FGF-2)، L-glutamine، nonessential amino acids and gentamicin. The cell surface antigens used for characterization were the SSEA-1، SSEA-4، TRA-1-60 and TRA-1-81 and the pluripotency markers were NANOG، OCT3/4 and SOX2. Results showed that، the growth rate of ESCs colonies in ESCs from IVF embryos was significantly higher than ESCs from HMG embryos (120% compared with 65%، respectively). Not only real-time PCR results revealed the same expression level of SOX2، OCT3/4 and cMYC between them، but also ESCs from HMG embryos resulted to higher expression of NANOG. Both of ESCs groups maintain in pluripotency state for more than two years and differentiated to the different types of cells like neuron، epithelial، lipid and muscle cells.

This study was carried out to study the inbreeding coefficient and its effect on reproductive performance of dairy cows (age at first calving، calving interval and open days) in Isfahan province. Records of 31،977 (primiparous cows)، 36،982 and 51،423 (multiparous cows) for age at first calving، calving interval and open days were used، respectively. The inbreeding coefficients of animals were calculated using pedigree information of 78،425 females and 8،056 males، which were born from 1963 to 2009. The overall mean and maximum inbreeding coefficients in Holstein cows were 2. 33% and 31. 30%، respectively. The results showed that 57،234 animals were inbred with 3. 57% inbreeding coefficient. Regression coefficients on inbreeding coefficient for age at first calving، calving interval and open days were 0. 589±0. 21، 1. 08±0. 15 and 0. 27±12، respectively. Estimated inbreeding indicated significantly negative effect on the reproductive traits in different parturition periods. The results revealed that the average inbreeding trend was increased in the dairy herds. The increased inbreeding was due to close mating systems between the candidates، and it showed negative effects on the reproductive traits in Isfahan dairy herds.