نشریه علوم دامی (پژوهش و سازندگی)
پیاپی 133 (زمستان 1400)

This study was performed to assess the effects of offering wheat straw as free choice with different particle sizes on ruminal fermentation, blood metabolites and nutrients digestibility of Holstein dairy calves. Individually housed calves (n = 40, BW = 43.8 ±3.2 kg) were used in a completely randomized design and divided to four different treatments consisting of: 1) starter feed without wheat straw supplementation (control; CON), 2) starter feed + wheat straw with 1mm geometrical mean particle length (GMPL, Fine), 3) starter feed + wheat straw with 4mm GMPL (Medium), and 4) starter feed + wheat straw with 7mm GMPL (Long). Calves entered the trial on d 15, weaned on d 56 and the study ended on d 90 of age. After morning feeding, the ruminal pH were increased by offering forage only at 8 h on d 35 and 4 and 8 h on d 90 (P = 0.05). The total short chain fatty acids concentration (SCFAs), molar proportion of acetate and propionate were similar across treatments, however, the molar proportion of butyrate increased (P = 0.04) in forage supplemented calves compared with CON calves. Regardless of forage particle size, dry matter and crude protein digestibilities were increased in forage supplemented calves compared with CON calves (P = 0.05). Moreover, no differences were found for different geometrical mean particle length of WS. Overall, free-choice provision of wheat straw enhanced ruminal pH, apparent nutrient digestibility, and rumen development indicators (BHBA) in Holstein dairy calves.

In this study, the effect of two sources of straw (wheat and rice) and two sources of non-protin nitrogen (urea and Nitroza) in full orange fruit silage on the quality of silage, growth performance and some blood parameters of Zell fattening male lambs were investigated. This study was carried out in a completely randomized design with 4 treatments and 6 replications on male lambs with mean age of 5.5 months and average weight of 24±2 kg for 75 days. Experimental treatments included: 1) 86.4 % orange+14.5 % wheat straw and 0.9% Nitrosa 2) 86.4 % orange+14.5 % wheat straw +0.9% urea 3) 86.4 % orange+14.5% rice straw + 0.9% urea 4) 86.4 % orange+14.5% rice straw +0.9% Nitrosa. Results showed that the addition of wheat straw to orange silage significantly increased dry matter, crude ash and NDF and decreased organic matter (P <0.05). The addition of urea significantly increased the amount of crude protein, crude fat and pH of the silage and reduced ADF and NFC (P <0.05). The results of growth performance showed that at the end weight, the highest and lowest daily gain were observed in treatments 1 and 3, respectively (P <0.05). The overall results showed that adding wheat straw with urea improved the chemical quality of silage. The growth performance of experimental lambs in dry matter intake and weight gain had the same results and no significant difference was obtained.

This study was done to investigate the effect of different levels of garlic powder on performance, relative weight of carcass components and blood metabolites of Japanese quail. One hundred 21-day male Japanese quails were randomly assigned to 5 treatments, 4 replicates and 5 birds in each replicate. The experimental treatment included: control diet without garlic powder, diets supplemented by 0.5%, 1%, 1.5% and 2% garlic powder. Quails fed for 21 days. Quails access to water and feed freely. Results showed that feed intake, daily weight gain and feed conversion ratio of quails were not affected by different levels of garlic powder. The effect of adding garlic powder to the diet on carcass efficiency, ventricular fat, total cholesterol and low-density-lipoproteins was significant (p <0.05). The birds fed diets containing 1% garlic powder had the highest carcass efficiency and the difference with birds fed diets without herbal medicine supplementation was significant (P <0.05). As increased garlic powder level in the diet, the blood total cholesterol and lipoproteins linearly decreased. According to the results obtained from this experiment, dietary supplementation by 1% garlic powder has a positive effect on carcass efficiency and decline undesirable blood metabolites.

In this study the effect of using silage of triticale fodder, vetch and their mixtures on the yield and blood metabolites of grey Shirazi male lambs was to investigated. The mentioned silages were evaluated in terms of physical characteristics and their chemical composition. Experimental treatments include: 1- Control (contains fodder corn silage); 2- Treatment containing triticale fodder silage; 3- Treatment containing forage vetch silage and 4- Treatment containing triticale and vetch fodder silage. Daily feed intake, weight gain, feed conversion ratio, blood metabolites as well as economic efficiency were determined. The highest amount of crude protein (P>0.01) and the lowest amount of neutral detergent fiber (P>0.01) were observed in vetch silage. The highest feed intake was observed in control treatment and the lowest in Treatment containing triticale fodder silage (P>0.01). Blood albumin concentration of lambs receiving control and Treatment containing forage vetch silage were significantly higher than other treatments (P>0.01). The use of silages of triticale, vetch and mixture reduced blood cholesterol (P>0.01). The highest amount of triglyceride was observed in lambs receiving treatments triticale fodder silage (2) and forage vetch silage (3). Income and income percent per kg live weight gain, increased with the use of low-water forage silages. Due to the ability to grow triticale and vetch plants in the conditions of lack of water resources in the country, these forages, especially triticale, have the potential to be used in the diet of ruminants.

In this study, first, the gas production content of spineless cactus (Opuntia ficus indica), alfalfa hay and spineless cactus-alfalfa silage were determined, then the effect of ensiling time on silage quality characteristics and nutritional value in day 30, 45, and 60 were examined. To prepare silage, the spineless cactus (66 %) was chopped and mixed with alfalfa (34 %) and ensiled in plastic bags. The collected data were analyzed in a completely randomized design with five replications. The gas production volume (ml) was significant difference among cactus, alfalfa hay, and cactus-alfalfa silage (P<0.05). The pH of the silage increased during ensiling on day 45 and 60 (P<0.05). Also, the lowest crude protein percentage and the highest ammonia nitrogen concentration were observed after ensiling for 60 days (P<0.05). The concentration of lactic acid and fleig point decreased after ensiling for 60 days (P<0.05). The concentration of oleic (cisC18:1), linoleic (cisC18:2) and linolenic fatty acids were highest on day 30 (P<0.05). The spineless cactus has a good digestible organic matter and its cultivation can be considered as an alternative feed. The high carbohydrates in spineless cactus improved the fermentation conditions and mixing it with alfalfa hay improved the quality of silage, so that the index of relative value of silage in all sampling periods was estimated to be favorable. Therefore, ensiling of cactus with a source of protein and fiber can be used to compensate for the lack of animal feed in hot and dry areas.

The effects of water type and hardness on performance, immune and biochemistry traits of blood, intestinal microflora population, meat and bone quality were evaluated using 192 male broiler chickens as a factorial arrangement (2 × 2) with four treatments and four replicates. The two factors studied were the type of drinking water (magnetized water and non-magnetized water) and the water hardness (normal-850 and hardess-2000 ppm). The results showed that in the whole period, the birds were received normal magnetized water showed a tendency to gain more weight compared to other birds were received other treatments (P = 0.09). Birds were received normal, magnetized, and non-magnetized water had more feed intake compared to birds were received hard magnetized water. Birds were received hard water consumed less water (P <0.05). Birds were consumed magnetic water had higher blood cholesterol and heterophilic to lymphocyte index than birds were received non-magnetic water (P<0.01). Birds that received hard water and magnetic water had less energy to break bones compared to birds that received normal water and non-magnetic water. The magnetization of hard water increased the population of lactobacilli in the ileum compared to birds were received non-magnetic hard water (P <0.001). Water hardness increased water holding capacity and decreased oxidation in meat. Thigh of birds were received magnetic water had lower concentration of malondialdehyde (P <0.01). Finally, magnetization of hard water increased the population of Lactobacillus ileum in the intestine, improved meat quality and reduced bone strength and feed intake without affecting feed conversion ratio.

The aim of this study was to investigate the effect of two mineral and organic forms of zinc on antioxidant activity and bone strength in the last phase of laying hens. 175 Leghorn laying hens (w36) with 80 week of age were divided into 7 treatments and 5 replications in a completely randomized design. The treatments were: control (without zinc supplementation) treatments containing zinc sulfate (15, 30 and 45 mg/kg). Organic zinc treatments (15, 30 and 45 mg/kg, respectively). The results showed that there was a significant increase in feed intake between the control treatment and 15 and 45 mg inorganic zinc and all organic zinc treatments (P<0.05). Egg weight in 45 mg inorganic zinc and all organic zinc treatments and egg mass in 15 and 30 mg organic zinc treatments showed a statistically significant increased. feed conversion ratio of organic zinc treatments was decreased significantly (P<0.05) . Regarding to egg quality traits, no significant difference was observed between experimental treats with control treatment (P>0.05). Both mineral and organic zinc supplements increased serum SOD activity as an antioxidant index at all levels (P<0.05). Tibial bone strength increased in laying hens of receiving 30 mg/kg organic zinc. According to the results, organic zinc can be improved feed intake and feed conversion ratio; Increased yield, antioxidant activity and bone strength in laying hens in the final stages of production.

This study was conducted to investigate the synbiotic and probiotic effects of two dietary supplements produced by Iran Scientific and Industrial Research Organization on growth performance and immune responses of broiler chicks challenged with Salmonella Typhimurium. 360 Ross 308 broiler chicks were studied in 6 treatments with 6 replications and 10 broiler chicks per replicate. This study was conducted in a factorial arrangement based on completely randomized design with 2 factors of challenge (challenge and non-challenge) and additives (lack of additive, 0.2 g/kg dietary supplement). Probiotic was containing Bacillus subtilis, B. licheniformis, and Saccharomyces cerevisiae. Synbiotic was contained same bacteria and fructans. Growth performance, including average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR), production index, and immunoglobulins G and M were investigated. The results showed that challenge with Salmonella decreased ADFI, ADG and production index compared to non-challenged broiler chicks (P<0.001). Challenge decreased the levels of immunoglobulins G and M compared to non-challenged broiler chicks (P<0.001). However, the results showed that dietary inclusion of supplements increased production index, ADFI and ADG and immunity compared to non-treated broiler chicks (P<0.001). In conclusion, the use of 0.2 g/kg of dietary supplements produced by this organization improves growth performance and immune responses against infectious challenges in broiler chicks due to their probiotic and synbiotic properties.

This current study was performed to evaluation of the effects of flaxseed on performance and some blood parameters in broilers. One hundred ninety-two one day-old Ross 308 broilers in 16 experimental units (12 birds in each experimental unit) were used with 4 treatments and 4 replications. Treatments include Treatment 1: Diet based on corn and soybean meal. 2) Diet with 2.5% flaxseed. 3) Diet with 5% flaxseed. 4) Diet with 7.5% flaxseed. Functional traits were measured periodically. Blood samples were taken at 21 and 42 days of age to measure some blood parameters. The results showed that the use of 7.5% flaxseed in the diet caused a significantly (P<0.05) decrease in daily weight gain (DWG). Inclusion of 5% flaxseed in diet significantly reduced glutathione peroxidase, superoxide dismutase and catalase enzymes activities (P <0.05). Based on the results of this study, dietary inclusion of 5% flaxseed in broilers diets is recommended.

This experiment was conducted to investigate the different levels of methionine in Standard and Low-protein Diets on Performance, Carcass Traits, blood metabolite and histology Parameters of growing Female Japanese Quails in a completely randomized design with 2 × 3 factorial arrangement. This experiment was consisted of two levels of protein (recommended level (NRC1994) and 10% higher than recommended level) with three levels of methionine (NRC recommended, 10% lower and 10% higher than recommended). This study, conducted with total of 480, 14-d quails that consisted of 6 treatments and 4 replicates and each replicate consisted of 20 chicks. The raising period for performance evaluation ranged from 14 to 35 days. All experimental diets were differed at crude protein and methionine, but other nutrients was in amount that recommended by NRC 1994. The results showed that interaction of crude protein and methionine had significant effect on body weight at 28, 35 days of age (P<0.05). Protein level had significant effect on total FCR (P<0.05), so lower FCR was resulted from chicks with 100 recommended level and also methionine level was significantly affect total fcr, so the %110 methionine level had better FCR than other levels . Experimental treatments had no significant effect on carcass constitutes and Blood metabolite, in female quails. Villus area, villus height to crypt depth ratio, and villus height was affected significantly by interaction of CP and Met (P<0.05). In conclusion, NRC 1994 recommended CP diet with 110 % Met level can improve quail production traits ,

The FecB gene is one one of the major genes associated with the twinning trait in sheep. AvaII enzyme has a restriction site containing FecB gene mutation is used for genotyping by PCR-RFLP method. Due to toxicity and expensive price, using this enzyme is not considered reasonable and economical. So, this research was performed to design specific primers for rapid and economical detection of FecB gene. Tetra ARMs PCR technique, caucuses elimination of AvaII enzyme, replacement of acrylamide gel by safe agarose gel, and of course saving time and money for genotyping. Four primers were designed, based of Tetra ARMs PCR method, and were tested on 3000 samples. After PCR and electrophoresis, three fragments with a length of 108, 213 and 276 bp were amplified and finally three genotypes were observed for FecB gene. In order to validate the designed primers, 20 samples were randomly sequenced. After validation, the result of this research indicates that the final obtained genotype in Tetra ARMs PCR method is same as the results from PCR-RFLP method. Tetra ARMs PCR method is rapid and economical for detection of FecB in a larger number of samples and can replace by enzyme digestion method which is all of more expensive.

Meta-analysis of genetic parameters for growth traits in Iranian sheep was performed by aggregating the reported genetic parameters of growth traits (birth weight, weaning weight, six months weight, nine months weight and yearling weight) in 80 papers published between 1996 and 2020. The studied parameters consisted of heritability values as well as genetic and phenotypic correlations between growth traits at different ages. Data analysis was performed in Comprehensive Meta-Analysis (Version2) software package using random effects model. The weighted average of heritability for growth traits was estimated in the range of 0.196 (birth weight) to 0.226 (yearling weight) and the weighted averages of genetic and phenotypic correlations were in the range of 0.318-0.915 and 0.221-0.769, respectively. Comparison of 95% confidence interval for genetic parameters obtained from meta-analyses with those mentioned in articles showed that aggregation of the results of different studies had significantly reduced the confidence interval ranges. Moreover, comparison of standard error of parameters in meta-analyses with those in different studies showed that the aggregation of results and subsequent increase in sample size reduced the standard errors of the genetic parameters. Therefore, comparing the results of meta-analysis in this study with the estimated parameters in individual studies showed that aggregation of results decreased the standard error and increased the accuracy of estimated parameters. Consequently, the results of meta-analysis studies can be more reliable compared to the results of individual studies to be used in breeding programs.