فصلنامه پژوهشهای تولیدات دامی
پیاپی 29 (پاییز 1399)

The current study was carried out to investigate the effect of dietary inclusion of soybean hull on performance, carcass characteristics and blood parameters of broiler chickens from the age of 1 to 42 days. A total of 240 day-old broiler chickens (Ross 308) which were randomly assigned to 4 dietary treatments with 5 replicates of 12 birds in each replicate. Experimental treatments were control diet and diets containing 2.5, 5 and 7.5% of soybean hull. Results of present study showed that, adding the soybean hull decreased linearly and quadratically (P<0.05) the average daily feed intake (ADFI) at starter, grower and the whole period, Inclusion of soybean hull in broilers diets reduced quadratically (P=0.02130) the average daily weight gain (ADWG) at starter period. The addition of soybean hull at grower period and the whole of period improved linearly and quadratically. (P<0.05) the feed conversion ratio (FCR) compared to the control treatment. Supplementing 5 percent of soybean hull in broilers diet significantly (P<0.05) increased the production efficiency factor (PEF) compared with the control diet. None of the carcass characteristics of broiler chickens were affected by experimental treatments (P>0.05). Also, different levels of soybean hull had no significant effect on blood parameters (P>0.05). The concentrations of Alanine aminotransferase in broiler chickens fed 2.5% soybean hull was significantly higher than the control group (P<0.01).  In general, the results of present study indicated that due to the positive impact of soybean hull on conversion ratio and production efficiency factor, it can be used up to 5% in broiler diets.

Effect of probiotic Bioplas 2B was tested on morphologic and cecal microbial populations in quails. Experimental treatments included control; 30 mg/kg antibiotic; 0.1% probiotic; 0.05% probiotic. 320 one-day quail with four experimental treatments in four replications were used in a completely randomized design. The best feed conversion ratio (FCR) was observed in quails fed with 0.05% probiotic and the worst FCR was obtained in quails of the control group which had a significant difference compared with other treatments (P<0.05). There was a significant difference in duodenal villi length (P<0.05). The highest values of crypt depth and thickness in fed birds were 0.1% probiotics, which, in contrast to 0.05% probiotic treatment, were significantly different from other treatments (P <0.05). The lowest depth and thickness of the crypt was also observed in the antibiotic treatment. The results of jejunal morphology showed that the use of probiotic treatment improved the vili length, villi thickness, crypt depth and crypt thickness compared to the control and antibiotic treatments (P<0.05). The probiotic treatment also improved the length of the villi and thickness compared to the control treatment. The probiotic treatment also improved the crypt depth and the thickness of the ileum fraction compared to the antibiotic treatment (P<0.05). In addition, the results of cecal microbial population showed that 0.1% probiotic treatment and control treatment increased Lactobacillus population and E. coli and total bacteria compared to other treatments. The results of the present study showed that probiotic supplementation significantly improved the morphology and microbial conditions of intestine in quails and can be a good alternative to antibiotics.

This research was conducted to investigate the effect of feeding processed shrimp waste products with gamma radiation on performance, carcass characteristics, blood parameters, liver enzymes and digestibility of broiler chicks. In this experiment, 560 one-day male broiler chicks (Ross 308) were allocated to 7 treatments, 5 replicates and 16 chicks per replicate in a completely randomized design. The treatments consisted of the basal diet (corn-soybean meal) and diets containing 5% unprocessed shrimp waste, 5% radiation processed shrimp, 10% unprocessed shrimp waste, 10% radiation processed shrimp, 15% unprocessed shrimp waste, and 15% of radiation processed shrimp waste. The results showed that in the starter, grower, finisher and whole growth period, chicks fed 15% of unprocessed shrimp waste had the lowest feed intake (P <0.05). Among treatments, the least weight gain was observed for treatments containing 15% unprocessed shrimp waste (P <0.05). In the grower, finisher and whole periods, the control and 5% radiation processed shrimp wastes showed the lowest feed conversion ratio (P <0.05). The percentage of thigh, breast and heart was higher in radiation treated treatments (P <0.05). In those treatments that containing 15% unprocessed shrimp waste, the abdominal fat pad percentage decreased. The effect of experimental treatments on the levels of serum triglyceride, cholesterol, LDL, HDL, AST and ALT concentrations at 21 days of age was not significantly different in broiler chicks (P>0.05). Increasing the level of shrimp wastes caused significantly reduced of LDL serum at 42 days of age (P <0.05). At 42 days of age, the highest levels of HDL serum was observed in the treatments containing 5% shrimp waste and control group (P <0.05). In the treatments containing 5% radiation processed shrimp waste, the digestibility of nutrients was similar to the control group (P <0.05). The results of this experiment showed that the use of radiation processed shrimp waste at 5% level was not a negative effect on the feed conversion ratio, weight gain and final weight of the birds, but also improved broiler chicken performance with increasing digestibility of the nutrients.

An experiment was done for studying different levels of Ca & P (with and without Phytaze enzyme) on liver enzymes and blood parameters in Arian broiler chickens. Two hundred eighty eight broiler chicken were used in a completely randomized design with 6 treatments and 4 replicates with 12 chickens in each floor pen.  Broiler chickens were fed with different levels of Ca and P (with or without Phytaze enzyme). Treatments included: control group (0.1Ca, 0.5P %) and other treatments were 15% and 30% Ca and P lower than control diet (with and without Phytaze enzyme), 15% Ca & P more than control diet. The results showed that in diet with 15% Ca and P lower than control group had maximum feed intake, body weight gain and minimum feed conversion ratio in total period. The liver of AST, ALP and LDH enzymes concentration were affected by different treatments. But ALT was not affected by treatments. Treatment significantly affected of blood parameter including P, N and K, but not effected on the Ca concentration in 21 and 42 days. In general, it can be concluded that the diet with 15% Ca and P lower than control group resulted highest feed consumption, body weight gain and best feed conversion ratio.

The aim of this study was to investigate the effect of protexin probiotic at the last month of pregnancy on ewes weight and birth weight of lambs, hematology and blood parameters of Lori Bakhtiyari ewes. For this purpose, 28 multiparous ewes that were pregnant in the last month and day of pregnancy was 120±5 used in a completely randomized design with 2 treatments and 14 replicates for one month. Treatments were: 1- control (ewes that did not take probiotic), 2) Ewes who ingested 1 gram of probiotic daily by mouth. The probiotic used in this study was protexin. The ewes were weighed immediately after calving. In order to determine the effect of the addition of protexin probiotic on hematology and blood parameters, blood sampling was performed immediately after birth. The results showed that adding probiotic in the last month of Pregnancy had no significant effect on ewes weight and birth weight of lambs. Also hematological parameters including eosinophil, lymphocyte, monocyte, neutrophil, hematocrit and white blood cell concentration were not significantly affected by probiotic supplementation. Among blood parameters, only the concentration of triglycerides increased (P=0.03), and other blood parameters including glucose, albumin, globulin, albumin-to-globulin ratio, total protein, gamma glutamyl transferase, glutamic oxaloacetic transaminase, alkaline phosphatase, acute phase proteins, Beta-hydroxy butyric acid, unsaturated fatty acids with multiple double bonds, and blood mineral elements were not significantly affected by the addition of protexin probiotics. Overall, the results showed that the addition of protexin probiotic in the last month of pregnancy did not have a significant effect on weight, hematology and most blood parameters of Lori Bakhtiyari ewes.

This experiment was conducted to investigate the effects of flaxseed essential oil (0, 60 or 120 mg/kg) on chemical composition, aerobic stability, and in vitro gas production of alfalfa silage. Experimental treatments include: alfalfa treatment without additive (control), alfalfa with 60 mg/kg flaxseed oil and alfalfa with 120 mg/kg flaxseed essential oil, which were kept at room temperature for 60 days. After opening the silos, gas production was measured by in vitro method with 5 replications at 2, 4, 6, 8, 12, 16, 24, 36, 48, 72, 96 and 120 hours. The data were analyzed in a completely randomized design. Addition of flaxseed essential oil at both levels (60 and 120 mg/kg) to alfalfa silage significantly reduced silage pH compared to control (p<0.05). Addition of essential oil to alfalfa silage had a significant effect on the dry matter content, so that in the supplemented treatment with 120 mg/kg, dry matter was increased (30.02%) compared to the control (24.43%). Adding flaxseed essential oil (120 mg/kg) to alfalfa silage increased crude protein (12.36%) and water soluble carbohydrate (4.61%) contents (p<0.05). Addition flaxseed essential oil at 60 and 120 mg concentrations to alfalfa silage significantly reduced (p<0.05) ammonia nitrogen compared to control treatment. Both levels of 60 and 120 mg of flaxseed essential oil reduced gas production volume compared to control (p<0.05). Overall, the data indicate a positive effect of flaxseed essential oil on alfalfa silage quality and its fermentation properties. silage quality and its fermentation properties.

This research was conducted in order to determine chemical composition, gas production parameters, in vitro digestibility and ruminal degradability of Acroptilon repens at different phonological stages (vegetative, flowering and seeding) and its comparison with alfalfa hay and wheat straw in Completely Randomized Design. For this purpose, Acroptilon repens was prepared in three stages of growth from Quchan pastures. The chemical composition of the samples was determined using the standard methods. The gas production test was used to estimate the gas production parameters of samples. In vitro digestibility of samples was determined by the batch culture method. Ruminal degradability trial was carried out by the nylon bag technique. The amount of Ash, crude protein (CP), Ether extract (EE), non- fiber carbohydrates (NFC) and neutral detergent soluble (NDS) at vegetative stage of Acroptilon repens were higher than wheat straw. At this phonological stage, neutral detergent fiber (NDF) and acid detergent fiber (ADF) were lower than wheat straw and alfalfa hay (p<0.05). The highest and lowest values of gas production potential were related to Acroptilon repens at flowering stage and wheat straw respectively (p<0.05). Estimated parameters including metabolizable energy (ME) and organic matter digestibility (OMD) at vegetative and seeding stages of Acroptilon repens were higher than wheat straw (p<0.05), but had no significant difference with alfalfa hay. The amount of dry matter digestibility of Acroptilon repens at vegetative and seeding stages did not differ with alfalfa hay and wheat straw, but was lower at flowering stage (p<0.05). OMD, microbial biomass (MB) and its efficiency (EMB) at vegetative stage of Acroptilon repens was higher than other treatments (p<0.05). Washout fraction (a) and potentially degradable fraction (b) of Acroptilon repens in all phonological stages was higher than alfalfa hay and wheat straw, meanwhile degradability of this plant at vegetative stage was higher than other treatments (p<0.05). Based on the results of this study and considering the chemical composition and fermentation parameters, Acroptilon repens at vegetative stage had higher nutritional value.

IIn this study, the effect of different levels of Scrophularia striata extract on the parameters of laboratory gas production, the concentration of volatile fatty acids and the activity of hydrolytic enzymes on the contents of the cecum of adult male rabbits were investigated. For this purpose, 20 New Zealand rabbits weighing approximately 1.6 ± 0.2 kg (5 months and up) were used in a completely randomized design with four treatments and five replications. Treatments included 1) without receiving Scrophularia striata extract (control), and supplementing the control diet with levels of 2) 200, 3) 300 and 4) 400 mg of Scrophularia striata extract per kg of body weight. The control group received 2 ml of water instead of the extract. At the end of the experimental period and after slaughter of rabbits, the contents of their cecum were sampled and the parameters of gas production, concentration of volatile fatty acids and activity of hydrolytic enzymes of cecal sample were determined. The results showed that consumption of Scrophularia striata extract reduced the volume of gas produced (p<0.05) and the total amount of volatile fatty acids (p= 0.01). Consumption of Scrophularia striata extract increased the activity of alpha-amylase (p= 0.02) and microcrystalline cellulase (p= 0.01) linearly, but did not significant e ffect on carboxymethylcellulose and filter paper decomposition activity. In general, the extract of the Scrophularia striata was able to affect the microbial and enzymatic activities of the rabbit colon, so that the microbial activity decreased with the consumption of this plant and eventually led to less gas production and reduced production of volatile fatty acids.production and reduced production of volatile fatty acids.

The effects of different levels of fish oil on productive and reproductive performance as well as serum biochemical indices in female Chukar partridges were evaluated. Thirty-six 1.5-year-old laying Chukar partridges and 12 age-matched males (female: male ratio of 3:1) were divided to four experimental groups (three replicates of three birds each) in a completely randomized, to orally receive 0 (control), 0.1, 0.2, or 0.3 mL of fish oil on a daily basis for 21 successive days where the control birds received 0.3 mL normal saline solution only as the sham control group. The birds had a free access to feed and fresh water and were weighed weekly. The eggs (n=271) were collected once per two hours during the photophase (8 times daily) for the last 21 days of the treatment period (from 7 through 28 d of experiment). Blood samples were collected on d 0, 10, and 21 of the trial to analyze selected biochemical attributes. Although administration of 0.2 mL fish oil increased the egg production and fertility rate, the difference was not significant as compared to the control group (p> 0.05). Feed intake, body weight, and daily weight gain were not influenced by the different levels of fish oil. A significant decrease in egg weight was detected in fish oil-fed birds where partridges receiving 0.2 mL fish oil recorded the lowest egg weight among the experimental groups (p< 0.05). Similarly, the birds administered with different levels of fish oil had lower serum total cholesterol and triglyceride levels compared to the control group where the lowest records were found for 0.3 mL fish oil level. The interaction effect of fish oil level and time on serum total cholesterol was significant (p=0.02). The serum levels of LDL and glucose were decreased in partridges receiving 0.3 mL fish oil (p<0.05). No significant changes in the serum concentration of VLDL, HDL, total protein, calcium, and phosphorus were found during the trial. Data suggested that oral exposure of Chukar partridge to 0.2 mL of fish oil had poitive effect on egg production and fertility rate. However, egg weight was decreased. Oral administration of 0.3 mL of fish oil may decrease serum total cholesterol, triglyceride, LDL, and glucose in partridges.

The purpose of this study was to evaluate the effect of replacing different levels of tomato pulp silage as a fiber source on yield, microbial fermentation, volatile fatty acid production and blood metabolites in Baluchi sheep. This study was conducted in a completely randomized design with 30 Baluchi lambs with 3 treatments of 10 lambs and average weight of 25 ± 1.5 kg. The trial period was 90 days. Experimental treatments include: 1). the basal diet only corn silage 2). The basal diet + corn silage containing 5% tomato pulp 3). The basal diet + corn silage contained 10% tomato pulp. Results of dry matter intake and body weight change showed no significant difference between the experimental diets. Based on the results of this experiment, plasma glucose concentration was normal in all experimental animals and were not affected by the experimental diets. The amount of rumen fluid in the experimental sheep decreased with the use of tomato pulp silage in the diet and had a significant difference (p<0.05) with the control group. In general, according to the results, using tomato silage as a by-product of up to 10% can improve production performance.

DNA methylation is a type of epigenetic changes that directly affects DNA. In mammals, DNA methylation is essential for fetal development and stem cell differentiation and this phenomenon essentially occurs within the CpG islands. In this study, two methods were used to study the DNA methylation profile of cow genome. In the first method, the DNA methylation profile of the differentially expressed genes from meta-analysis of DNA microarray data on mastitis were obtained. In order to perform the meta-analysis in the first method, the metaDE package in R environment, was used. Then five algorithms including TJ, GF, CpG cluster, HMM and GHMM were used to predict CpG islands in different genes. In the second method, DNA methylation profiling was performed using whole cow genome scanning. Also, for prediction of methylated CpG islands in whole genome, HMM algorithm was first estimated in bovine genome for each chromosome and then CpG overlap with Hypo / Hyper-Methylation was calculated by Galaxy Online database. The results of the first method showed that among 32 differentially expressed genes, 14 genes involved methylated CpG islands. These genes included LTF, APP, CCL5, CD40, CSNK1D, CX3CL1, DAPP1, NFKBIZ, S100A9, ISG15, MAP3K8, MX1, RDAD2, ZC3H12A. Results of the second method identified a total 90668 Hypo / Hyper-Methylation in the bovine genome, among which 9942 (10.96%) CpG islands overlapped with Hypo / Hyper-Methylation and were considered as methylated CpG. Genomic comparisons were also made between species for DNA methylation. The results showed that the overall DNA methylation profile was almost similar for majority of studied species and it seems that the overall profile of DNA methylation is likely to be conserved between different species. The results of this study showed that DNA methylation seems necessary in diseases with low heritability and which are more influenced by epigenetic processes.

In the present study, blood samples were collected from 97 Adani goat from Bushehr province in order to identify the polymorphism in the exon II region of MHC-DRB1 gene (Major Histocompatibility Complex) and also, its association with growth traits (birth weight and 3 months weight). Genomic DNA was extracted from blood samples. A 279-bp fragment was amplified using polymerase chain reaction (PCR). Eventually, the PCR products were digested by RasI enzyme. The results showed that there were 4 types of alleles A, B, C and D in this locus with the frequencies of %51, %26.8, %13.4 and %8.8, respectively. Five genotypes including AA, AB, BB, AC and AD were identified with the frequency of %14.432, %28.866, %12.371, %26.80 and %17.525, respectively. The results indicated polymorphism and high heterozygosity in the population under study. Also, the number of effective alleles, Shannon index, expected and observed heterozygosity for this site was calculated at 2.794, 1.179, 0.642 and 0.732, respectively. Moreover, the chi-square (χ2) test showed that population was not in Hardy-Weinberg equilibrium. The ANOVA results showed that the effect of different genotypes on birth weight was significant (p<0.05), but it was not significant on 3 MW (p<0.05). Furthermore, other traits such as dam age, sex, season and birth type effects were not significant on the growth traits (p<0.05). The highest birth weight was found for heterozygous AC and AD genotypes (3.05 and 3.02 Kg, respectively), and the lowest birth weight was related to pure AA genotype (1.75 Kg). It seems that selecting AC and AD genotypes can be expected to increase birth weight in Adani goat. Also, we expect that this gene can act as a candidate gene for genetic improvement of some growth traits in goat breeding programs.

G-protein-coupled receptor (GPR54) is one of the known gene affecting fecundity. This gene  affects  the ovulation rate and litter size performance. A total of 160 animals including Sanjabi (n=100) and Ghezel (n=60) were used to identify polymorphisms of GPR54 gene and  their influence on litter size. Genomic DNA was extracted by commercial DNA kit. The genotypic patterns were detected using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). The genotypic patterns frequencies for three detected patterns in Sanjabi sheep were 54.93, 17.59 and 17.59 percent, and for two detected patterns of Ghezel were 41.86, 58.14 percent, respectively. Significant association (P<0.05) was identified between detected genotypes with litter size in Sanjabi, but no significant association (P>0.05) was found between detected polymorphisms with litter size in Ghezel sheep. Although the  results showed that the detected polymorphisms  in this gene can be used as a marker for twinning in Sanjabi sheep but,  it may be necessary to carry out further studies with larger sample sizes to find an exact correlation between GPR54 gene variants and fecundity trait.

The aim of this study was to identify the factors affecting the culling of dairy cows and their impact on reproductive performance and costs of the herd so that optimal decisions can be made in replacing dairy cows and thereby increase the annual income of dairy cattle. For this purpose, data collected from four active cattle breeding units in Ardabil province (including biological parameters and financial information of herds) during the years 2017 to 2018 were used. To simulate the herd status under different conditions, a bio-economic model developed in Dairy VIP software was used, and the MATLAB software compecon toolbox was optimized for production system. Dynamic programming was used to determine the optimal replacement strategy. This planning is a mathematical approach that is suitable for solving problems with several successive decision steps. Dairy cattle were described with state variables including lactation period, milk production capacity and different animal health states. The average annual milk yield and forced removal rate were 13480 kg and 16.1%, respectively. According to the observed results, the highest total annual culling rate occurred when the rate of pregnancy of productive animal decreased by 5%. The major effective changes in economic performance due to the reduction in the rate of forced culling was related to the reduction in the cost of purchasing alternative heifers. The average herd optimal life (interval between first calving to removal) was obtained for the baseline scenario of 4.99 years. The optimal annual replacement rate, which is equal to the sum of the optional and non-optional elimination rates, was 20% for the baseline scenario in this study. So that culling of dairy cows older than the optimum age leads to increased profitability of livestock units. The results of the dynamic programming model also showed that optimal maintenance for medium and high-yielding cows is equal to seven and eight lactation periods. The results of this study can help producers to identify important factors in annual herd profitability and to make sound management decisions to improve economic profit.

The aim of this study was to identify the lack of function mutation of p.R12X affecting reproductive problems and abortion in SLC37A2 gene by PCR-SSCP and sequencing methods in Holstein and Montbeliarde cows, For this purpose, 250 blood samples (150 Holstein and 100 samples of Montbeliarde) were prepared and DNA was extracted by kit. A pair of specific primers was designed with Oligo7 software to amplify a fragment with length of 208 bp from exon 2 of the SLC37A2 gene, which contains mutation. Genotyping was done by SSCP method and allelic and genotypic frequencies and population genetic indices were calculated by POPGEN software. In SLC37A2 locus, two AA and AB genotypes with frequencies of 98.7 and 1.3, and 86 and 14% were observed in Holstein and Montbeliarde breeds, respectively. Also, SLC37A2 allelic frequencies in both Holstein and Montbeliarde for alleles A and B were estimated to be 99.3, 0.7 and 93 and 7%, respectively. The Fischerchr('39')s exact and Chi-square tests for comparing allelic and genotypic frequencies between two populations showed that there was a significant difference in allelic and genotypic frequencies between Holstein and Montbeliarde population (P <0.05). After genotyping, a sample of each genotype was sequenced in both end and the bioinformatics of the sequences obtained were performed with BioEdit software. The results showed that in the AB genotype of SLC37A2 gene in Holstein and Montbeliarde cows there was a lack of function mutation (p.R12X). Considering the role of p.R12X mutation in reproductive defects and abortion in Montbeliarde cattle, the results of this study can be directly used in the breeding programs to identify carrier animals and culling them from commercial and rural herds.

One of the most important and complex management decisions in dairy farms that greatly affects the economy and profitability of the dairy herd is the issue of culling. Regarding the importance of the subject, this study aimed to investigate the culling status and causes of Holstein dairy cattle in Qazvin province. For this research, the culling data of 35 industrial dairy herds under the cover of Qazvin Farmerschr('39') Union were collected and analyzed during one year. Herds were categorized into five categories(treatments) of dairy cows including herds by capacity less than 100 (low), 100-200 (relatively low), 200-500 (average), 1000-500 (relatively high) and more than 1000 heads (high)., The culling data were analyzed in a completely randomized design in two main categories of forced and optional removal. The results showed that there was a significant difference in mean parity of the cows between the different treatments and mean parity decreased with increasing capacity of the studied cows. The mean parity of culling cows in the studied herds in Qazvin province was 3.92. There was no significant difference between different treatments in the percentage of fresh cows, primiparous cows as well as the percentage of productive cows (lactating and dry). Clinical mastitis accounted for 5.08% of total culling in dairy herds and there was no significant difference between treatments for this disease. BLV disease accounted for 1.25% of the total culling in the dairy herds studied and the difference between relatively high and high treatments were significant (P≤0.05). There were no significant differences between treatments for acidosis, abomasal displacement, ketosis / fatty liver, milk fever and bloat. The results of this study showed that in high capacity dairy herds (more than 500 heads), cows are culled earlier from the herd. The voluntary removal ratio in industrial dairy herds in Qazvin province was 27.67%. The most important factor for removal in these dairy farms was infertility and reproductive malformations with the ratio of 31.85%.

Nutritional and hormonal programs are one of the important ways of improving goat reproductive performance. Therefore, the present study was conducted to investigate the effect of using barley seed and eCG at the same time on the reproductive performance of goat in nomadic breeding conditions. The number of 60 goats of two to three-year-old in the breeding season and 60 goats of three to four-year-old in out-breeding season were chosen. Then the goats were divided into six groups of 10 numbers. 1- Control group (without receiving barley seed and eCG); 2- Group receiving 400 grams of barley for eight days (short term); 3- Group receiving 400 grams of barley for 16 days (long term); 4- Group receiving 400 IU eCG; 5- Group receiving 400 IU eCG and 400 grams of barley for eight days and 6- Group receiving 400 IU eCG and 400 grams of barley for 16 days. The results indicated that in-breeding season twinning rate in groups receiving barley for short and long term with eCG were higher compared to the group without receiving eCG. At the same time, the minimum (five) and maximum (20) numbers of  born kids were observed in control and group six, respectively. The results also indicated that in out-breeding season none of the characteristics were influenced statistically by treatments. It can be concluded that using 400 IU of eCG and 400 grams of barley seed daily, can improve the twinning rate in breeding season but such an effect cannot be observed in out breeding season.