Due to the threat of vaccination problems and antibiotic resistance, more appropriate approaches are desired to breed disease resistance animals that are now practiced in cattle, sheep, chicken, and fish farming. Over the recent century, breeding programs based on the productive characteristics have increased animals' overall growth rate and produc-tivity. Despite the benefits, livestock breeding with this method has caused many physiological disorders as well as a reduction in overall immunocompetence. This issue highlights the importance of genetic considerations during the process of breeding. One of the most crucial gene clusters identified in animals is the major histocompatibility complex (MHC), which plays a crucial role in the immune system to distinguishing self from non-self. Recent studies have demonstrated that some MHC regions are highly polymorphic. Also, a significant association between different MHC alleles and susceptibility/ resistance to various diseases has been found. This review summarizes the recent research on MHC polymorphism and its association with immune responses in domestic animals

BACKGROUND: The immunostimulating effect of Aloe vera in mammals has been documented, but few works were done on effect of A. vera on fish health and immune responses. OBJECTIVES: In this study the effect of oral administration of A. vera on growth indices, hematological parameters and immune responses of rainbow trout were investigated. METHODS: One thousand five hundred rainbow trout fingerling (20 ± 2 g, Mean ± SD) were divided into five groups, each in triplicate, in farm scale. Group 1 were adopted as control and fed with non-supplemented feed, groups 2 to 5 were fed with diet supplemented by 0.05%, 0.1%, 0.2% and 0.5% A. vera extract respectivly for 60 days. Growth indices (SGR, FCR, PWG, FER, PER and CF) calculated in day 30 and 60. Blood samples were taken in day 60 and hematological parameters including: PCV, Hb, RBC, WBC, MCH, MCV, MCHC as well as immunological parameters including: Lysozyme and serum bactericidal activity, serum total protein and globulin were compared among the groups. RESULTS: Results showed that all calculated growth indices (except CF) and all mentioned immunological parameters were significantly increased in fish fed with 0.1% and 0.2% A. vera supplemented food (G3 and G4) compare to control group (P < 0.05). Hematological parameters, HB, RBC, WBC and PCV showed a significant enhancement in G3 and G4 compare to control (P<0.05), but MCV, MCH and MCHC showed no significant changes (P > 0.05). CONCLUSIONS: It can be concluded that oral administration of 0.1% and 0. 2% A. vera crud extract in food (G3 and G4) can improved growth indices, stimulate non-specific immune responces and affect some hematological parameters positively in rainbow trout.

BACKGROUND: Recently, the researches about herbal medicines as substitutes for chemical drugs have risen in number. OBJECTIVES: To add more aspects to this research area, this study evaluated the changes in biochemical factors of the blood serum due to the consumption of Thymus daenensis extract and the effect of the period of its consumption into the diet of herd dogs. METHODS: Eight adult male dogs were chosen and fed with a fixed diet for 1 month. Then they were ran- domly assigned to two groups of four. The members of first (control) group were fed only with the fixed diet and the second group received 200mg/ml, administered as 1ml/kg of Thymus daenensis extract into their fixed diet. Finally, the dogs were bloodlet at 3 different times, namely before intervention, 7 and 14 days after the in- tervention to measure the factors of glucose, cholesterol, triglyceride, LDL and HDL, alanine aminotransferase and aspartate aminotransferases. RESULTS: Comparing to the control group and the starting point of this experiment, levels of FBS, LDL, TGL, CHOL, AST factors significantly decreased 14 days after intervention, but the HDL factor increased after 7 and 14 days of intervention (P<0.05). The level of ALT factor did not change during period of the study (P> 0.05). CONCLUSIONS: Consequently, oral consumption of Thymus daenensis extract led to decrease in the amounts of glucose and lipids of blood and this herb can be recommended for treating diabetics and persons suffering from high cholesterol.

Background: Nutritional strategies targeting improvement of poultry performance and disease prevention are currently being developed and in this respect the dietary intake of spiced essential oils and pre-biotics in raising broilers is receiving attention. OBJECTIVES: This study was conducted to compare the effects of diet containing ginger essential oils (GEO) and mannan-oligosaccharide (MOS) on growth performance,  biochemical and hematological parameters, lymphoid organ weights and antibody response of broilers. METHODS: A total of 375 day old male broiler chicks were randomly assigned to five treatments (five replicates per treatment). Dietary treatments included basal diet as control, GEO-supplemented diets with inclusion levels of 50 (GEO1), 100 (GEO2) or 200 (GEO3) mg/kg, and MOS supplemented diet with an inclusion level of 2 g/kg. RESULTS: The birds fed on MOS and GEO3 diets exhibited better feed conversion ratio and higher body weight gain from 1 to 42 day of age compared with control birds (p<0.05). Serum low density lipoprotein cholesterol level in the MOS, GEO2 or GEO3 groups was lower than that of the control group (p<0.05). Serum cholesterol level was also lower in the GEO2 and MOS groups (p<0.05). Feeding on GEO3 and MOS diets significantly increased relative bursa weight and secondary antibody titer against infectious bursal disease (IBD) and infectious bronchitis (IB) vaccines as compared with control diet (p<0.05). CONCLUSIONS: The results showed that higher level of GEO (200 g/kg) similar to MOS supplementation, improved feed efficiency and immune response. This could meet consumers’ demand for a safe feed additive.

BACKGROUND: Occurrence of resistance against antibioticsand inadequate efficacy of some vaccines necessitates studies ofnatural immunostimulators in aquaculture. Shrimps shell derivedfrom Chitosan can be used as immune stimulators in fish.OBJECTIVES: In this study, the effects of oral administration ofchitosan, derived from shrimp shell, on some immune responsesand disease resistance in Cyprinus carpio were studied. METHODS:Three hundred healthy fish weighing 42.4+8.1 g were divided into4 equal groups: the first group (G10) was fed with foodsupplemented with 10 mg kg-1 chitosan, the second (G5) and thirdgroups (G2.5) were fed with food supplemented with 5 mg kg-1 and2.5 mg kg-1, respectively. The control group was fed with basal feed(without chitosan). All groups were treated for 60 days. Bloodsamples were taken on 0, 20, 40, and 60 days post- experiment; Inaddition, some immunological indices, including serum lysozymeactivity, serum bactericidal activity, Nitro Blue Tetrazolium (NBT)reduction activity, serum proteins, white blood cell count (WBC),and differentiated count were measured. At the end of the treatment,fish were challenged with live Aeromonas hydrophila and mortalityrate was recorded for 14 days. RESULTS: Oral administration ofchitosan (0.5 and 1%) significantly enhanced NBT reductionactivity and resistance to A. hydrophila infection (p=0.012). Serumlysozyme and bactericidal activity, serum total protein andglobulin, WBC and leukocytes ratio showed no significant changeamong the groups (p>0.05). CONCLUSIONS: This study indicatesthat oral administration of shrimp shell chitosan may have a positiveeffect on some immune parameters and resistance against bacterialinfection in Cyprinus carpio.

BACKGROUND:Herbal methionine can be compared relative toDl-methionine with evaluation of bioavailability of this source ofmethionine. OBJECTIVES: An experiment was carried out todetermine the relative bioefficacy of herbal methionine (H-Met)®relative to DL-methionine (DL-Met) on performance criteria andimmunocompetence of Met sources in male broilers. Atotal of 160male broilers were fed a Met-deficient basal diet or the basal dietsupplemented with three or four concentrations of each Metsources. METHODS: Multiexponential and multilinear regressionswere used to determined bioavailability of herbal methionine (HMet)®relative to DL-Met on performance and immunocompetenceof broilers. RESULTS: Body weight gain and feed intake of thebroilers fed H-Met or DL Met improved in the experiment,regardless of Met sources, relative to those broilers that were fed thebasal diet. Immunocompetence of broilers were not significant at 28day of age (p>0.05), whereas the broilers were significantlyaffected by the additional levels of Met sources at 42 day of age.CONCLUSIONS: The bioefficacy estimates for H-Met® relative toDL-Met on a product basis were 55% for weight gain, 71% for feedintake, 78% for feed conversion ratio, 70% for dilution 1-choloro 2-3-dinitrobenzene (DNCB), 67% for sheep red blood cell (SRBC),and 68% for phytohemagglutinine (PHA-P). The relativeeffectiveness of H-Met® compared to that of DL-Met is 68% onaverage across performance criteria and all immune criteria tested.H-Met®can be supplemented as a new and natural source of Met forthe poultry industry.

BACKGROUND: Salmonella enterica serovar Typhimurium (ST) is a gram-negative facultative intracellular bacterium with the ability to infect a wide range of hosts. OBJECTIVES: This study aimed to provide a snapshot of the immune responses against ST challenge in primary chicken monocyte-derived macrophages (MDMs) by evaluating the transcriptional changes in inflammatory cytokine interleukin (IL)-1β. METHODS: After preparing blood MDMs, cell monolayers were challenged with ST at a multiplicity of infection of 50. Transcriptional analyses of inflammatory cytokine IL-1β were performed by reverse transcription-quantitative polymerase chain reaction using SYBR Green dye. RESULTS: The results indicated that wildtype ST challenge in avian MDMs favors the differentiation of macrophages toward the alternatively activated M2-like cells through downregulating inflammatory IL-1β. CONCLUSIONS: The findings demonstrated the preferential differentiation of chicken macrophages toward the alterna-tively activated M2-like cells upon ST infection. Further improvement of the existing control measures, such as vaccination and molecular-based immunotherapeutic strategies against poultry salmonellosis requires a better understand-ing of mechanisms involved in the immunomodulatory actions of Salmonella in immune cells in future studie