مجله علوم دامی ایران
سال پنجاه و پنجم شماره 2 (تابستان 1403)

This study was conducted to evaluate the effects of acid hydrolyzed processing on the nutritional value of soybean meal (SBM) and its influence on the growth performance, intestinal morphology, microbial population, digestive enzymes activity, and nutrient digestibility in broiler chickens fed with diets containing different levels of crude protein. A total of 300 one-day-old male broiler chickens were used in a design with 6 treatments and 5 replicates per each during 1 to 42 days of age. This experiment was conducted as a completely randomized design with a 2 × 3 factorial arrangement of treatments including two types of SBM (raw and treated with 0.50% citric acid) and three inclusion rates of crude protein (90, 95 and 100 % of  requirements). The results showed that acid-treated SBM improved feed conversion ratio in broilers compared to raw-SBM group (P < 0.05). The decrease of protein requirements up to 90% declined growth performance of broilers compared to 95 and 100 % of requirements (P < 0.05). The villus length was greater in broiler chickens fed with acid-treated SBM compared with raw-SBM group (P < 0.05). Meanwhile, reduction of protein requirements decreased the villus length, the ration of villus length to crypt depth and villus surface in broilers (P < 0.05). Acid processing of SBM increased digestibility coefficient of crude protein and protease and amylase activity in broiler chickens (P < 0.05). In addition, a decrease in protein digestibility and enzyme activity was observed in broilers fed low protein (90 % of the requirements) diet (P < 0.05). Based on the results of this study, it can be concluded that acid processing of SBM improved its nutritional quality. Also, use of acid-treated SBM increased growth performance, intestinal morphometric indices, digestive enzymes activity and nutrient utilization in broiler chickens. In addition, reducing of crude protein requirements up to 95% in diets containing citric acid-treated SBM had not negative impact on growth performance in broiler chickens.

Replacing corn with oak fruit in the poultry diet can lead to a decrease in dependence and the outflow of currency from the country, but oak fruit has a large amount of anti-nutritional compounds (tannins), which can be a limiting factor in its consumption. Therefore, it is necessary to investigate the effects of different amounts of oak fruit in the diet on the performance and immune system of poultry in order to determine the appropriate levels of oak for use in poultry rations. This study aimed to investigate the expression of cytokine genes in the spleen tissue of broiler chicken fed with a diet containing oak acorn. For this purpose, three rations containing 0, 15, and 20% oak acorn were used to feed broilers for a period of 42 days. At the ages of 21 and 42 days, the spleen tissue was separated from 18 slaughtered broiler chickens (6 from each treatment), and the total RNA was extracted. The expression of cytokine genes including IL-2, IL-4, IL-5, IL-10, IL-13, and IFN-γ were investigated in all three treatments. Beta-actin gene was also included in the experiment as a reference gene. The REST, 2009, V2.0.13 software was used for the analysis of gene expression data. According to the results, the expression of the IFN-γ gene showed a significant increase in the spleen tissue of broiler chickens fed with 15% oak acorn with respect to the control group at both 21 and 42 days of age (P<0.05). In the 20% oak acorn group, although the IFN-γ gene expression was higher than the control treatment at both ages, this difference was not significant. At the age of 21 days, the mRNA levels of the IL-4 gene also showed a significant increase in the diet containing 15% oak acorn compared to the control group (p<0.01). On the other hand, at the age of 42 days, the expression levels of interleukin 2 and 4 genes showed a significant decrease in the treatment of 15% oak acorn compared to the control group (p<0.05). Furthermore, the mRNA levels of IL-5, IL-10, and IL-13 genes showed no significant difference in treatments containing oak acorn at both the ages of 21 and 42 days compared to the control group. In general, replacing corn with oak acorn in the diet of broiler chickens, based on the amount and duration of consumption, can lead to changes in the expression of immune system genes in the spleen tissue.

This study was conducted to investigate the effect of different levels of alkaline hydrolyzed feather meal (AHFM) on the performance, intestinal morphology, and meat oxidation of Arian broiler chickens from d 15 to 42. A total of 480 one-day-old chickens of two sexes (equal ratio) were randomly distributed among 24 pens (20 chicks per experimental unit). The four experimental diets contained different levels of feather meal (0, 2, 4, and 5 %), which were replicated six times. During the grower period, daily weight gain decreased and the feed conversion ratio increased at 4 and 5 % AHFM levels (P<0.05), also feed intake increased in birds fed on a 5 % AHFM diet (P<0.05). In the overall experimental period feeding 4 % AHFM decreased the body weight gain compared to control (P<0.05) and the feed intake was reduced in birds fed on 2 % AHFM (P<0.05). The feed conversion ratio has not been influenced by the level of AHFM 15-42 d. Diets with AHFM decreased the jejunum villi height, while this reduction in the ileum was observed at 4 and 5 % AHFM, and goblet cell density increased at 5 % AHFM (P<0.05). With the increase in the level of AHFM, the concentration of malondialdehyde in fresh breast, and thigh meat decreased so that the group receiving five percent of AHFM had the lowest concentration of malondialdehyde (P<0.01). The level of 5 % AHFM reduced the litter moisture (P<0.05) and the levels of AHFM did not affect the concentration of the litter ammonia. None of the mortality, production efficiency index, and feed cost per kilogram of live weight were significantly affected by experimental treatments. As a general conclusion, the use of AHFM reduced the body weight and increased the feed conversion ratio of Arian broilers without affecting the mortality rate and production efficiency index, although meat oxidative stability improved.

The aim of this study was to evaluate the effects of different levels of oak Acorn on the biodiversity of rumen epimural bacterial population using PCR-SSCP molecular technique in Merkhoz goats. A total of 24 Markhoz goats with a mean BW of 16.93±1.25 kg and an average age of 4–5 months were tested in a completely randomized design with 4 treatments and 6 replications for 105 days. Experimental treatments included 1) control diet, 2) diet containing 8% oak acorn, 3) diet containing 17% oak acorn and 4) diet containing 25% oak acorn. The results showed that the effect of diet on biodiversity of rumen bacterial epimural community was significant (P <0.001). There was no significant difference between other experimental treatments (P> 0.05), although treatments containing 8% and 17% oak had more variety than treatments containing 25% oak. Sampling site had no effect on biodiversity of rumen bacterial epimural community (P> 0.05). The highest value of Shannon index was related to ventral ruminal site and the lowest was related to reticulum. The interaction effect of diet and sampling position on biodiversity of rumen bacterial epimural community was significant (P> 0.05). The results showed that the use of oak acorn up to 17% in the diet increased the biodiversity of the of rumen bacterial epimural community, while the use of 25% oak in the diet decreased the biodiversity of the rumen bacterial epimural community.

The aim of the present study was to evaluate the effect of dietary metabolizable energy levels (EL) and stocking density (SD) on growth performance, blood indices, jejunal morphology and meat quality in Arian broiler chickens. A total of 672 Arian one-day-old chicks were used in a completely randomized design with 2×4 factorial arrangement, including two stocking density (12, 16 birds/m2) and four energy levels (EL1: Arian recommendation energy level, EL2: 3.5% higher energy level for finisher2, EL3: 3.5% higher energy level for all periods, EL4: 3.5% higher starter, grower and finisher1 and 6.1% higher energy level for finisher2) with eight treatments and six replicates. The results showed that recommendation Arian catalogue energy level with 16 birds/m2 decreased body weight gain in the finisher2 (42-36 days) and the whole period (1-42 days) and had highest feed conversion ratio in the finisher2 (P<0.001). Increased energy level (EL3) significantly decreased feed intake in finisher2 period. The carcass efficiency, breast relative weight and abdominal fat as increased as energy levels enhanced. In HSD, EL2 compared to EL3 increased relative weigh of heart. Also, EL3 increased low-density lipoprotein and alanine transaminase concentration in HSD. Concentration of albumin, total protein and high-density lipoprotein were decreased by stock density, on the contrary, Superoxide dismutase and glutathione peroxidase increased (P<0.05). The lowest height of villi was related to EL1 in HSD, and the highest villi height was observed in EL4 and low stock density. High energy level increased the villus width, the ratio of the villus height to the crypt depth (VH/CD) and the absorption area (P<0.05). HSD significantly reduced villus height and width, VH/CD and absorption area of villus (P<0.05). The interaction of energy level and SD did not affect any of the meat quality indicators. Furthermore, the findings of the present study showed there is no significant difference between 12 and 16 birds/m2 during the whole of period. The HSD decreased the growth performance and had a negative effect on the feed conversion ratio, whereas improved the performance of Arian broiler chickens when increased the energy level by 3.5% in the finisher 2.

Twenty-four male lambs with an average weight of 28.73±3.64 kg and age of three months were assigned to four treatments with 6 lambs for each treatment in a completely randomized design. The treatments included: the control (basic diet), treatment 1: basic diet + 10 grams of supplement (60% cumin, 30% coriander and 10% peppermint), treatment 2: basic diet + 10 grams of supplement (45% cumin, 45% coriander and 10% peppermint), treatment 3: basic diet + 10 grams of supplement (30% cumin, 60% coriander and 10% peppermint). Blood was taken from the jugular vein of the lambs at the end of the experiment. DMI was not affected by treatments. Average daily gain (ADG) in the treatment 1 was higher than that of control treatment. Hemoglobin, PLT, RBC, and WBC, percentages of lymphocytes, monocytes and neutrophils were not affected by the supplements. No significant difference was observed between the experimental and control treatments in terms of blood glucose and triglyceride concentrations. Blood urea was higher in the treatments 2 and 3 than in the control. Aspartate aminotransferase and alanine aminotransferase increased in treatments 2 and 3 compared to the control. Alkaline phosphatase and gamma-glutamyl transpeptidase in the treatment 3 were different from the control. Glutathione peroxidase and superoxidase dismutase did not change, but the antioxidant capacity in experimental treatments decreased compared to the control. The results showed that the addition of 10 gram of cumin, coriander and peppermint mixture with ratios of 30, 60 and 10, respectively, improved the performance of Roman lambs and feed efficiency without having an adverse effect on blood metabolites.

The aim of this research was to study different economic selection indices to increase body weight in Markhoz goat breed. Body weight (BW) at different ages (birth, weaning, 6-month and 9-month) were categorized as several two- and three-traits selection indices. Genetic parameters were estimated with MTGSAM using the Bayesian statistical method. Selection index analyzes were done using SelAction software. The results of comparing three-trait indices showed that highest total economic gain resuled from I9 which was US$4.86. The total economic response for two-trait index belonged to I4 which was US$3.94 and higher than 5 others. The highest direct genetic gain from three-trait indices was predicted for 9-month weight in I8 and I9 indices to be about 0.63 kg. In addition, the highest direct genetic improvement resulting from two-trait indices was also predicted for the 9-month weight in the I3 to be 0.66 kg. Moreover, the selection and performance criteria revealed decrease in phenotypic variance, heritability, and genetic correlation of traits. These changes differed in alternative selection schemes, which influenced by the initial population parameters, selection intensity, direct or indirect selection, and the number of traits included in the selection index. In conclusion, to maximize the total economic gain, two selection indices I9 and I4 can be suggested for the current condition of the Markhoz goat population. However, to preserve the phenotypic/genetic variance of traits, it is necessary to focus on strategies such as selection intensity, economic coefficients, indirect selection, and increasing the number of traits in selection indices.

The aim of this study was to evaluate the effect of removing iron from mineral premix before calving on the productive performance and health status of Holstein dairy cows during transition period. The ninety multiparous Holstein dairy cows entered the experiment -21 days before the expected calving and were randomly assigned to 3 experimental treatments. Treatments included: 1) control treatment: recipient of mineral supplement with iron (to supply iron requirement in the amount of 15 mg/kg; n = 30); 2) treatment without iron: recipient of mineral supplement without iron (n=30); 3) without supplemental iron treatment with cottonseed: recipient of mineral supplement without iron and 4.6% of cottonseed in the diet (n=30). Removing iron from mineral supplements with and without cottonseed had no significant effect on milk production, percentage and amount of milk fat, as well as the amount of milk protein. The somatic cell count (SCC) in the control treatments, without supplemental iron and without supplemental iron with cottonseed, were 471.48, 338.80 and 155.77 (103 per ml), respectively, which significantly decreased in the treatment without supplemental iron with cottonseed. Body weight changes after calving were also affected by experimental treatments. Removing iron from the mineral supplement along with cottonseed reduces the incidence of hypocalcemia. Total birth weight of both male and female calves, body length, hearth girth and days of diarrhea showed a significant difference between the treatments. Overall, the removal of supplemental iron along with cottonseed reduced the SCC and also improved the health status of cows and their calves.