نشریه علوم دامی (پژوهش و سازندگی)
پیاپی 131 (تابستان 1400)

To investigate the effect of adding dried rumen contents on performance, production, milk composition and blood parameters in Holstein dairy cows, twelve Holstein dairy cows with average daily milk production of 36.25±3Kg and 111±6 days in milk in a completely randomized design with two treatments and 6 replicates were used. Treatments included control (basal diet; no dried rumen contents) and experimental treatments (control diet with 60 grams of dried rumen contents per day).. The cows were kept in individual pens and fed a total mixed ration ad libtium. The results showed that the addition of dried rumen contents in the diet had no significant effect on feed consumption in Holstein dairy cows co+9[[3+pared to the control group. Milk production was significantly increased in cows fed rumen-dried contents compared to the control group (P <0.05). Also, supplementation of dried rumen contents significantly increased milk fat percentage (P <0.01). Supplementation of dried rumen contents in the diet resulted in a significant increase in blood glucose, calcium and phosphorus levels (P <0.05) and a significant decrease in blood urea nitrogen (P <0.05). Also, increasing the content of dried rumen in the diet led to a significant increase in high-density lipoprotein in cow's blood serum (P < 0.05). According to the results of this experiment, the use of 60 g of dried rumen content in dairy cows is likely to improve performance.

This experiment was conducted to evaluate the effects of supplementation of zinc and inorganic selenium in diets containing oxidized oil on performance, antioxidant enzymes activity, and meat quality of broiler chickens. A total of 480 day-old Ross 308 broiler chickens were randomly attributed into 12 treatments with four replicates each with 10 chickens in 2×3×2 factorial arrangement, includes: The thigh was dissected and muscles were removed to assess the malondialdehyde (MDA) content. The results showed that the birds’ average daily FI and FCR were not significantly influenced by dietary treatments. Inversely, the average daily BWG showed a significant difference among treatments over the experimental period (P <0.05). The birds received dietary Zinc at the level of 100 mg showed a higher activity of SOD enzyme (P <0.05). The lowest amounts of GPX was observed in birds fed diets containing oxidized oils, no dietary zinc and selenium at the level of 3.0 mg/kg. The highest and lowest levels of thigh meat MDA levels were noted in birds received diets containing oxidized oil with no dietary zinc and those had given fresh oil diets with supplementary zinc at 100 mg kg zinc and supplementary Se at 0.3 mg/kg, respectively. The results of this study revealed no synergistic effects between zinc and selenium on oxidative enzymes and MDA levels. It is recommended to supplement 100 mg / kg of zinc and 0.3 mg / kg of selenium to reduce the peroxidation effects of dietary oxidized oil.

Goat's milk has a higher nutritional value and therapeutic benefits than cow's milk, but the goaty flavour and taste limits the acceptability of dairy products derived from goat's milk. In this research two types of yogurt prepared: Mahabadi goat's milk yogurt and yogurt made with mixture of Mahabadi goat's milk and Holstein cow's milk. The physicochemical characteristics (total solid, protein, fat, acidity, pH, synersis, water holding capacity and viscosity), microbial (enumeration of yeasts and moulds) and sensory evaluation of yogurt samples were investigated during 28 days storage at 4°C. The results showed that total solid, protein, pH and acidity of goat's milk yogurt and yogurt made of yogurt made from mixture of goat's and cow's milk were not significantly different, but fat was significantly (p < 0.05) higher in goat's milk yogurt . In terms of synersis, water holding capacity and viscosity, no significant differences were observed between goat's milk yogurt and yogurt made from mixture of goat's and cow's milk. None of the yogurt samples were contaminated with yeast and mould. Evaluation of scores of odor, flavour, taste and overall acceptability showed that yogurt samples made from mixture of goat's and cow's milk had significantly (p <0.05) higher scores than those of goat's milk yogurt and were preferred by sensory panelists. According to results of this research, the production of fermented products by combining goat's and cow's milk is an appropriate opportunity to cover its goaty flavour while maintaining its nutritional value and sensory characteristics accordance with consumer's preference.

The aim of the research was to investigate the antibacterial potential of local isolates of probiotic bacteria in the presence of herbal extracts including Chamomile (Matricaria chamomilla), Fennel (Foeniculum vulgare), Peppermint (Mentha piperita) and thyme (thymus vulgaris). Lactobacillus casei(TA0021), L. plantarum(TA0028,TA0026), L.reuteri(TA0034), Enterococcus faecium(TA0033) and Pediococcus acidilactici(TA0049,TA00170) were used as probiotic bacteria, while standard strains of Escherichia coli, Salmonella typhimurium and Salmonella enteriditis were used as indicator organisms. The antibacterial activity of the mentioned probiotic isolates and the herbal extracts against the selected pathogens were examined by agar well diffusion method. The synergistic effect of the mix of probiotic bacteria and different herbal extracts(1:10,1:100 and 1:1000) were also studied. The viability and synergistic inhibitory effect of the selected probiotic bacteria in the presence of different concentrations of herbal extracts were determined after 24, 48 and 72 hours. In order to determine the minimum inhibitory concentrations (MIC), herbal extracts were serially diluted and their effect on fixed concentrations of the indicator organism was measured by microdilution assay. Similarly, the survival percentage of probiotic bacteria in the presence of different concentrations of the herbal extract was determined. MIC values were recorded as the lowest concentration of extract that was able to inhibit the growth of the pathogens. All experiments were performed in triplicate and results analyzed statistically(Using the SAS Software). According to the results the probiotic bacteria in the presence of different concentrations of the extracts was above 70%(P<0/05). Overall, the locally isolated probiotic bacteria with herbal extracts are strong antibacterial agents.

Forty eight 10-d old Farahani neonatal lambs (6.8 ± 1.8 kg of body weight) were allocated (n = 12 lambs per treatment; 6 males and 6 females) in a randomized completely block design with 2 × 2 factorial arrangement including the factors of alfalfa hay (AH) supplementation level (low, 10%; or high, 30% on DM basis) and grain source (corn vs. barley). Hence, treatments were: (1) barley grain (BG) with 10 % of AH; (2) BG with 30 % of AH; (3) corn grain (CG) with 10 % of AH; and (4) CG with 30 % of AH. All lambs had ad libitum access to water and starter feed throughout the experiment. Further, no interaction was detected between forage supplementation level and grain source for starter intake, average daily gain (ADG) and feed efficiency. Lambs fed low level of AH had greater betahydroxy butyrate (BHB) concentration in serum on d 30 and 60 of the study (P < 0.01 and P = 0.02, respectively). Lambs received barley-based starters had greater blood urea nitrogen concentrations than corn-based diets on d 60 of the study. Treatments had no effect on skeletal growth characteristics of sucking lambs on d 30 and 60, however, high level of AH supplementation decreased (P < 0.01) hip width compared with low AH inclusion. In general, results showed that AH supplementation at high level could decrease growth performance; however, grain source had no effect on suckling lambs performance.

The effect of adding hypotaurine antioxidant on reduction of lipid peroxidation and improving motility of Rooster sperm during freezing and thawingThe aim of the present study was to investigate the antioxidant effect of hypotaurine at levels of 0.25, 0.5, 0.75 and 1 mM in lecithin-based Lake extender during the freezing and thawing process on motility, survival, plasma membrane integrity, the amount of MDA in the semen and sperm morphology parameters. For this purpose, semen samples were collected from 15 roosters by by abdominal massage method twice a week. After diluting and addation of different levels of antioxidants, the samples were frozen on liquid nitrogen vapor. After thawing, the samples were evaluated for sperm performance parameters. Results indicated an increase in sperm velocity parameters, total motility, progressive motility, viability, membrane integrity by adding 0.75 mM/L hypotaurine antioxidant compared with the other groups (P<0.05). Also, the level of 0.75 mM was significantly reduced (P <0.05) in the amount of MDA in the semen and the highest level was obtained in terms of these parameters at this level. The results showed that adding the optimal level of hypotaurine could play a protective role against lipid peroxidation and improve the appearance of rooster sperm during freezing and thawing and reduce the damage caused by oxidative stress.

This experiment was conducted to investigate the effect of graded creatine monohydrate levels on diets at different levels of protein on carcass characteristics and hematological parameters. A total of 320 Ross 308 one-day-old broilers were in the form of 2*4 factorials, with four levels of creatine (zero, 0.1, 0.3, 0.5%), and two levels of protein (requirements of Ross 308 and 10% higher), with four replicates, were used. Blood sampling was performed at 35 days of age. To investigate the carcass characteristics, at the end of the experiment two birds at each replicate were randomly selected, weighed and slaughtered. 10% higher protein requirement increased daily weight gain, live weight, carcass yield, relative liver, and breast weight, and decreased feed conversion ratio and abdominal fat (P<0.05). Adding 0.3% and 0.5% creatine monohydrate to the diet increased live weight, carcass yield and relative weight of breast and thigh compared to other groups (P<0.05). Protein and creatine levels had no effect on immune cells and Newcastle titer; however, the data indicated a numerical increase in lymphocyte, monocyte and Newcastle titer and a decrease in heterophil. Creatinine concentration in the blood of birds fed with 0.3 and 0.5% creatine monohydrate was higher than broilers fed with 0.1% creatine monohydrate and control group (P<0.05). The results showed that moreover the beneficial effects of creatine at high levels and 10% higher protein requirements on growth performance and carcass traits, blood creatinine concentrations should be increased which could potentially improve immune system function.

Being aware of the animals` food requirement, the amount of available forage in the rangeland and forage quality is necessary as the first step in successful management of animals and rangeland. Therefore, determining the weight of various animals` classes grazing in the rangeland and their conversion factor regarding country`s animal unit is an essential issue. In this research, to determine the weight of various classes of Zandi sheep grazing in the Lar National Park rangelands of Aroo region, three prevalent flocks of Zandi race were selected randomly and from each flock, 60 heads of animals including 20 heads of ewe ageing 3 years old, 20 heads of ewe aging 4 years old, 5 heads of ram aging 3 years old, 5 heads of ram aging 4 years old and 10 heads of lamb aging 3 months were signed and selected in two phases, one at the beginning of the season and the other at the end of season. Having utilized the mean weight of ewes aging 3 and 4 years, the weight of the sheep glazing in the studied region was estimated to be equal to 1.65±48.03 kg. Various kinds of forage being glazed by the sheep were identified and collected in this rangeland through two phases of flowering and seeding. The mean percentage of CP, ADF, DMD and ME in every kg of dry forage equaled to 11.56, 37.78, 56.88, 7.69 mega joule, respectively.

This experiment was conducted to determine the metabolizable energy of wheat, barley and corn produced in Iran using biological method (in vivo) and comparison with equations and estimates obtained from NIRs and NRC. Wheat, barley and corn grains were chemically analyzed according to AOAC standard methods and NIRs. Biological method was performed using 48 adult roosters (Red Island) at the age of 83 weekswere using the precision-feeding method. Results of using equations for wheat and barley the highest amount of metabolizable energy (3.71 and 3.45 kcal / g) and the lowest (3.11 and 2.87 kcal / g) by equations respectively Carpenter and Jensen were observed (P <0.05). Corn grain showed the highest amount of metabolizable energy (3.91 kcal / g) by Carpenter and Jensen equations and the lowest amount of metabolizable energy (3.06 kcal / g) by EEC equation (P<0.05).The amount of metabolizable energy obtained from biological methods for corn, wheat and barley (3.323, 3.1724 and 2.9543 kcal / g), compared to standard NRC tables (3.350, 3.120, and 2.640 Kcal / g) and NIR (3.324, 3.324 and 2.735 kcal / g), respectively (P<0.05). It is suggested that equations be prepared for domestically produced cereal cultivars and that rations be adjusted according to the amount of energy variation. Because this variation is important in regulating feed economically and cost-effectively.

This study was to investigate the effect of Portulaca oleracea L. extract(POE) on performance, carcass characteristics, immune response, blood indices and intestinal morphology in broilers under heat stress. 200 Ross 308 single-day-old chicks were used in a completely randomized design with 5 treatments, 4 replications and 10 chicks. Experimental groups were: negative control (no heat stress), four groups under heat stress (positive control), 250, 500 and 750mg of POE per kg diet. Results showed that using POE increased feed intake and body weight compared to the control (P <0.05). Chicks fed POE had lower feed conversion ratio than positive control group (P<0.05). Addition of POE to broiler diet had no effect on relative weight of carcass components including breast, thigh, spleen, bile, pancreas and abdominal fat. The POE reduced the relative weight of heart and liver compared to the positive control and the relative weight of bursa was higher in the chicks fed the POE (P<0.05). The POE increased total antibody titer against sheep red blood cells. Using the POE in broiler diet had no effect on plasma concentration albumin and protein, but the lowest concentration of cholesterol, triglyceride, LDL and highest HDL were observed broilers fed 750 POE. The activity of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase enzymes decreased during heat stress compared to negative control. POE increased villus height and absorption area compared to control(P<0.05). It is concluded that using POE reduced plasma concentration of cholesterol, LDL, and plasma MDA in broilers under heat stress.

Fresh citrus pulp (FCP) was mixed with wheat straw (WS) 90:10 and ensiled in three treatments 1) 0.0% urea, 2) 0.5% urea and 3) 1% urea, using 40 kg nylon bags. After three months of ensiling, silos were evaluated and sampled for chemical analysis and in vitro gas test. In vivo digestibility and intake of the silages were determined in sheep nutrition along with basal diet (Alfalfa hay+WS+barley ground). Dry matter (DM) ranged 19.32 to 21.15% and pH 3.59 to 3.74 in silages. Crude protein and NH3-N were increased (P<0.05) in silages contained urea. There were no significant differences between silages for gas production. The in vivo digestibility of DM, OM and NDF, and ME were similar between the basal diet and the experimental diets as well as the experimental silages. However, digestibility of CP was increased in silages contained 0.5 and 1% urea (P<0.05). An increasing trend was observed for DM intake where the animals received ad-libitum silages than the basal diet. Daily urine weight and urine pH was increased (P<0.05) when the animals fed 1% urea silage, comparison to the other diets but, ruminal pH was not affected by the treatments. Finally, it is concluded that ensiling of FCP plus WS to provide a mixture with optimum DM content may be an appropriate method of preserving and using of this by product in ruminant nutrition. In addition, deficiency of CP could be compensated by addition of proper amount of urea.

The limitation of feed sources in Iran and all over the world has increased attentions to use alternative feedstuffs. Insect production is one the recommended approaches to improve food security for human and animals. Insects are rapidly grown and proliferated and because of being cold-blooded have appropriate feed conversion ratio. They also can convert agricultural residues into biomass contained proper value of energy and protein. This article has been focused on introduction of some insects used in poultry neutrino (including cricket, mealworm, black soldier fly larva, house fly larva, grasshopper) and earthworm, followed by reviewing the poultry nutritionist’s results about them, and ended up with pointing the challenges regarding to the extension of insect usage in poultry nutrition. The results of the researches indicated the appropriate levels of crude protein (42.1-63.3%) and metabolizable energy (3833-3298 kcal/kg) in evaluated insects or larva and the possibility of using them in poultry feed (commonly 5% of diet). Regarding the challenges of insect production and usage, some points which need especial attention are included: developing legal instructions for authorizing insect production and usage, choosing safe and proper insect species, type of litter and substrate of feeding, the chitin content of exoskeleton, as well as appropriate marketing and cultural education of the poultry farmers and human consumers of the poultry products.

The present study was undertaken to investigate the effects of dietary substitution of corn silage on dry matter intake, production and reproductive performance, and nutrient digestibility of Mahabadi lactating goats. In this case, a total of twenty pregnant female goats with 2-5 years old were selected and attributed into two groups of ten goats regarding to age, weight and the numbers of calving. The experiment was done based on completely randomized design. Experimental treatments consisted of diet control and dietary substitution of forage part with corn silage at 20 percentage of dry matter. The ratios of concentrate to forage in diet were 45 to 55 and 57 to 43 in pregnancy and lactation periods, respectively. Results showed that dietary inclusion of corn silage had no significant effects (P>0.05) on body weight and metabolic body weight alterations in pregnancy and lactation periods. Feeding corn silage didn't affect (P>0.05) daily and metabolic feed intake in both pregnancy and lactation times, colostrum and daily milk production, reproductive parameters of goats, and kids weight. Feeding silage corn silage in diet led to significant increases (P<0.05) in organic, organic in dry matter, and crude protein digestibility and tended (P=0.09) to increase in neutral detergent fiber digestibility. In general, results indicated that dietary inclusion of corn silage not only had no adverse effects on reproductive performance of pregnant goats, but also it could improve nutrient digestibility of Mahabadi lactating goats.

In order to evaluate the effect of dietary levels of Peganum harmala seed powder (PHS) on performance and carcass characteristics of broilers, an experiment was conducted in a completely randomized design with 4 treatments and 4 replicates of 18 birds in each for 6 weeks. The experimental treatments included control diet (containing corn and soybean meal) and diets 2, 3 and 4 contained 0.02 percent virginiamycin growth promoter antibiotic, 0.25 and 0.50 percent PHS, respectively. The feed intake, body weight, body weight gain and feed conversion ratio were measured at the end of each production period and also in whole experimental period and mortalities were recorded daily. At the end of experimental period, two birds were selected from each replicate, slaughtered and carcass and abdominal organ characteristics and weight and length of different parts of intestine were measured. The results of this study showed that in grower, finisher and whole production periods, the feed intake, body weight and body weight gain of chickens fed diet containing 0.50 percent PHS were significantly (P<0.05) lower than those of other treatments. The abdominal fat percentage of chickens fed diet containing 0.50 percent PHS was highly significantly (P<0.01) lower and their proventriculus, gizzard and duodenum percentages were significantly (P<0.05) higher than those of other treatments. According to the results of this experiment, it seems that although the dietary utilization of PHS powder reduces performance however can increase broiler carcass quality and oxidative stability via reduction in abdominal fat percentage.

Broodiness, a maternal behavior and instinct for natural breeding in poultry, inhibits egg production. The turkey is one of the most important species having strong broody behavior and affects the poultry of its industry. Broody genetic and environmental factors influencing broodiness in poultry have been extensively studied, but the molecular regulation mechanism of broodiness is somewhat unclear. In this research, pituitary transcriptome of commercial turkey broiler from BUT breed was studied during the laying and broodiness phases. A total of 334 differentially expressed genes were identified. There were 229 upregulated and 104 downregulated at egg-laying phases compared with brooding phases. In the present study analysis of genes using KEGG software revealed that the genes in the Protein processing in endoplasmic reticulum pathway (P <0.05) are critical for controlling broodiness in the turkeys. Gene network analysis revealed that CANX, HSPA8, P4HB, HSPBP1 and ATF4 may act as important modulators of hormonal and behavioral mechanism associated with broodiness.