ANIMAL SCIENCE RESEARCHES (FACULTY OF AGRICULTURE, UNIVERSITY OF TABRIZ)
Year:2020 | Volume:30 | Issue:2|Papers Count:10

Introduction: Inbreeding, which has been defined as the mating between relative animals, leads to increase homozygous genotypes and decrease heterozygous genotypes in a population. As a result, the progenies of such mating are inbred (Wakchaure and Genguly 2015). Reduction of the traits associated with physiological efficiency and reproductive potential are the most important impacts of inbreeding in the farm animals (Filho et al. 2015, Fleming et al. 2018). Traits in livestock have different heritabilities suggesting that they are not influenced by inbreeding in a similar pattern and that although animals’ fitness is generally deteriorated; the magnitude of inbreeding depends on the type of the trait (Roff 1998; Derose and Roff, 1999, Wright et al. 2008, Mikkelsen et al. 2010). Until now, all studies regarding effects of inbreeding on productive and reproductive traits of dairy cows have been focused on using the statistical models in which inbreeding coefficient was included as covariable (Behmaram et al. 2017) or as the classified variable (Amirzadeh 2012). As inbreeding coefficient is defined as a covariable in the model, only a regression coefficient is estimated describing average changes of the trait per increasing / decreasing inbreeding coefficient. As a matter of fact, inbreeding may unequally influence the shape of distribution of the trait. Based on this assumption, this research aimed to estimate inbreeding effects on some productive and reproductive traits of Iranian dairy cows using Quantile regression statistical method. Material and methods: The data set was provided by Animal Breeding Centre, Iran. Foxpro (version 2. 6) and UEStudio (version 09) software were utilized for editing initial data. Final data consisted of 580, 802 records belonging to 580, 802 first-parity cows distributed in 1, 185 herds (over 20 provinces of the country) and calved between years 1991 and 2015. The traits under consideration were lactation milk yield (TMILK), 305d, 2X milk yield (MILK3052X), average daily milk yield (ADM), lactation length (LL), and age at the first calving (AFC). The average of the traits in the final data set was 9, 447 Kg, 7, 792 Kg, 30 Kg, 315 d and 25. 6 m, respectively. Holstein gene percentage (HGP) of the cows in the pedigree file was set to be in the range of 50 to 100 and AFC of the cows was set to be between 18 and 48 months. Inbreeding coefficient (IC) of individual animals was calculated by CFC software (Sargolzaei et al. 2006). Fitting a series of the Quantile regression models was conducted with the use of SAS (version 9. 4) software. Quantile regression, which was introduced by Koenker and Bassett (1978), extends the regression model to conditional quantiles of the response variable, such as the 90th percentile. Quantile regression is particularly useful when the rate of change in the conditional Quantile, expressed by the regression coefficients, depends on the Quantile (Chen 2005). In all the models used in this research, fixed effects of province, year and month of calving, as well as linear co-variables of HGP, IC and AFC (except of the model for AFC as the trait) were included. For TMILK, lactation length was also included as linear co-variable. Moreover, in addition to the quantile models and for the sake of estimating usual regression coefficient, general linear model (GLM) was also fitted for each trait in which a single regression coefficient of the trait on IC was defined. Ordinary least-squares regression can be used to estimate conditional percentiles by making a distributional assumption such as normality for the error term in the model. The main advantage of Quantile regression over ordinary least-squares regression is its flexibility for modeling data with heterogeneous conditional distributions (Chen 2005). Results and discussion: Based upon the analysis of main pedigree file, the total number of animals was 1, 941, 871 (16, 169 sires and 895, 376 dams) among which the number of base and non-base animals were 246, 388 (3, 936 sires and 120, 287 dams) and 1, 695483 (12, 233 sires and 775, 089 dams), respectively. Total number of inbred animals in the pedigree was 1, 211, 343. Average IC for total as well as inbred animals was found to be 0. 9149% (minimum 0% and maximum 47. 02%) and 1. 4651% (minimum 0. 00038% and maximum 47. 02%), respectively. For the cows with records for all five traits, IC ranged from 0 to 38. 45% with the average of 1. 13% (SD=1. 63%). Estimate of annual change of IC was found to be 0. 017 (SE=0. 005), which was statistically significant (P<0. 01) indicating that there is a positive increase of inbreeding in Iranian dairy cows’ population over the time. Within each trait, different Quantiles were unequally influenced as animal’ s IC increased. Vast majority of the estimated regression coefficients in different Quantiles were statistically significant (P<0. 05). Based upon fitting Quantile regression model and the average estimated regression coefficients, it was found that TMILK, MILK3052X, ADM, LL, and AFC changed-5. 5 (Kg),-2. 6 (Kg),-18 (g), 0. 35 (d) and 0. 30 (d), respectively as the IC of the animal increased by 1%. Estimated simple regression coefficients based on fitting GLM models were found to be-9. 83 Kg (SE=1. 332 Kg),-6. 9 Kg (SE=0. 169 Kg),-32 gram (SE=4. 2 gram), 0. 2087 d (SE=0. 08234 d) and 0. 0158 m (SE=0. 0024 m), respectively and all were statistically significant (P<0. 05). Conclusion: This research indicated that different Quantiles of some productive and reproductive traits of Iranian dairy cows are not equally affected by inbreeding phenomenon suggesting that Quantile regression models are needed to be utilized in the future research for evaluating the impacts of inbreeding on the other traits, which are of great economic importance.

Introduction: Ghezel is an Iranian medium-sized and fat-tailed sheep breed and is native in the East and West Azarbaijan provinces. Ghezel sheep plays an important role in supplying meat and milk in the region of Azerbaijan (Ghasemi-Panahi et al. 2016). Also, an important source of farmer's income is lambs production (Nabavi et al. 2015). Therefore, one of the prospects for improving the region's production is improving reproductive performance of sheep flocks. In order to suggest a proper approach to improve reproductive performance, there should be a comprehensive information from the livestock farms of these two provinces. Therefore, the present study was conducted with the aim of evaluating reproductive performance of Ghezel ewes in a couple of sheep farms in the East and West Azarbaijan provinces. Materials and method: After designing questionnaire in this study, 30 Ghezel sheep flocks were randomly selected from different regions of East and West Azarbaijan provinces (15 flocks in each province). Then, livestock farmers of the region were interviewed using questionnaire and information on reproductive performance of flocks were collected including: pregnancy rate, multiparty, lambs' birth weight, age at the first parturition, weaning age, lambs weaning weight, number of unfertile and fertile ewes, flock surface area, farmers' education, and etc. The flocks were divided into four flock sizes. The breeding systems were also studied based on the three groups of nomadic, rural, and industrial breeding systems. The results of the questionnaires were reported as percentages (for classified data) and mean ± SD (for other data). Also, correlation coefficients between important traits were calculated using Spearman’ s rank-order correlation of SAS 9. 2 (2008) software. Results and discussion: Based on the results of this experiment, 87% of the breeding systems of two provinces were rural. Other reproductive indexes of two provinces included 65% lambing rate, 79% pregnancy rate, 24% ewes' fecundity rate, 20% estrus synchronization usage, 5% flock mortality rate, 9% ewe's infertility rate, 0. 1 ram to ewe ratio, and 17 months of age for ewes at the first mating. Seifi et al. (2014), with evaluating Ghezel and Afshari sheep breeds, reported low reproductive performance in these two breeds. Khodayi-Motlagh et al. (2014) reported low knowledge of farmers about the methods of estrus synchronization. However, a number of studies reported an extraordinary improvement in the reproductive performance of Ghezel ewes using different methods of estrus synchronization or using flushing rations (Najafi et al. 2014; GhasemiPanahi et al. 2016; Hasani Dash Tapeh et al. 2017; Ahmadzadeh et al. 2018). Therefore, it seems that improving knowledge and skill of farmers about estrus synchronization methods and/or proper rationing can improve reproductive performance of Ghezel sheep in the region. According to the correlation results, there was a negative correlation between the breeding system and the flock size (correlation coefficient:-0. 6) and between the flock size and estrus synchronization usage (correlation coefficient:-0. 51), (P<0. 05). These results indicated that the breeding system has been changed into the nomadic system in the larger breeding flocks and there is a less interest in the use of new methods of estrus synchronization in this kind of breeding system. Also, results indicated a significantly negative correlation (correlation coefficient:-0. 42) between ram to ewe ratio and lambing rate (P <0. 05). So, regardless of the role of rams on flock fertility, asymmetrical increase in ram to ewe ratio causes a negative impact on lambing rate by reducing the ewe population (which are the animals whom produce lambs). The results showed a significant positive correlation (P <0. 05) between lambing rate and the age of ewes at the first mating (correlation coefficient: 0. 54) and also the age of ewes at the first delivery (correlation coefficient: 0. 66). These positive correlations indicate poor rearing condition of young ewes and are consistent with the general believe of farmers, which they breed ewes at the second year (age 16-18 months) to obtain optimum fertility rate. Results showed a negative correlation between the age of ewes at the first mating and birth weight of lamb (correlation coefficient:-0. 60), while indicating a positive correlation between the age of ewes at the first mating and age of weaned lambs (correlation coefficient was 0. 49), (P <0. 05). These results can be explained by higher fecundity rate in older ewes, which reduces lamb birth weight, while it increases weaning age of lambs. The negative correlation (correlation coefficient:-0. 41) between weaning age of lambs and estrus synchronization use (P <0. 05) can be due to the fact that lambs from the synchronized ewes born and weaned at the same time and then, reared under better nutritional and management conditions. Conclusion: The overall results of the present study showed low reproductive performance in the Ghezel sheep flocks of East and West Azarbaijan provinces due to the low use of estrus synchronization methods and poor management. Therefore, it seems that by informing the farmers about the new methods of estrus synchronization, raising their level of knowledge in this field, ration training, and management of synchronized animals can improve reproductive performance and increase profitability in the region.

Introduction: Nanotechnology can be very effective in increasing productivity through food, nutrition, hygiene and breeding of livestock, poultry and aquatic animals. Nanotechnology has received a great attention within scientific and industrial communities in many countries including Iran. Nanotechnology, as a powerful new technology has the ability of creating massive revolution in feed supply and agricultural systems at global scale by improving diet quality and consequently health and growth performance (Buzea et al. 2007). One of the reasons for the extensive use of these particles in poultry units is due to their antimicrobial properties. Nanotechnology deals with structures that their dimensions are approximately between 1 to 100 nanometers (Sriram et al. 2010). Silver nanoparticles are among widely used nanoparticles. The interest in the use of silver based antimicrobial agents was primarily due to the emergence of antibiotic resistance among microbial populations and due to the fact that resistance to silver is not commonly encountered (Prestinaci et al. 2015). Nanoparticles according to their size, have new properties in comparison with mass materials. Silver nanoparticles in many characters are more effective compared with other metals. In addition, beneficial effects of silver nanoparticles are due to the size and resemblance of nanoparticles which caused their passage through the biological membrane and through the cell (Wang et al. 2015). Silver nanoparticles because of their small size for proper homogeneity can be coated by zeolite particles. Zeolite has been used in broiler feed due to its resistant chemical structure and it’ s not digested and catalyzed by passing through the digestive tract. Also, zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations. Among many properties attributed to zeolites, two of the most characteristics that relates to their effectiveness in animal nutrition are their ability to lose and gain water reversibly and being capable of exchanging selectively a variety of cations in their structure without much changes of structure (Wawrzyniak et al. 2017). Therefore, zeolite can be considered as an appropriate carrier for nanoparticles. Based on these facts, silver nanoparticles had been replaced instead of massive particles of silver and been more effective in different industry. Silver nanoparticles lead to the production of reactive oxygen species and oxidative stress in cells (Ahmadi and Kurdestani. 2010). Liver as the biggest gland in the body has several roles. In addition to digestive and metabolic activities, liver has immunological and detoxification activity (Maser et al. 1994). Silver nanoparticles can inter the cells and communicate with intracellular structures (Panzarini et al. 2018). The ability of silver nanoparticles to infiltrate into tissues led to resistance against their removal in blood and then, cause particles aggregation in utilizable tissues. Due to the reports of the aggregating and dangerous effects of silver nanoparticles, it seems necessary to histopathologically investigate liver and kidney of broiler chicken fed silver nanoparticles. Material and methods: This experiment was performed at the Poultry Research Station Faculty of Animal Science at the Gorgan University of Agricultural and Natural Resources. This experiment was designed to evaluate the effect of silver nanoparticles coated on zeolite and organic acid on liver and kidney histology in broiler chickens. A total of 375 one-day old broiler chicks (Cobb 500) was randomly assigned into five treatment groups containing of five replicates with 15 birds in each replicate. Five dietary treatments groups were, (1) basal diet (control), (2) basal diet containing 1% zeolite, (3) basal diet containing 1% of zeolite-coated with 0. 5% silver nanoparticles, (4) basal diet containing 0. 15% organic acids and (5) basal diet containing 1% of zeolite-coated with 0. 5% of silver nanoparticles and 0. 15% a mixture of organic acid. The basal diet prepared for starter and growth periods, and composition of the experimental diets prepared according to the requirements prescribed for Cobb 500 (Cobb. 2012). Birds has ad libitum access to feed and water for all treatment groups and continuous lighting program was provided during the experiment. Two chickens per each replicate were slaughtered on day 42 for evaluating the histology of liver and kidney. The tissue samples were fixed in a 10% buffered formalin, processed through graded alcohols and xylene and embedded in paraffin blocks. Tissue sections were cut for 5 m at multiple levels and routinely stained with haematoxylin-eosin (H&E). Mounted slides were examined and photographed under a light microscope. Hepatocytes and kidney cells were evaluated for histopathologic lesions, focal point of lymph nodes in the liver parenchyma, around the portal region and focal point of heterophobia. Data were analyzed based on a completely randomized design using general linear method (GLM) procedure by using SAS (2003) software. Mean comparison was done by Duncan's multiple range tests at 5% level with values of P<0. 05 being considered significantly different. Results and discussion: The experimental results didn’ t show any significant difference between experimental treatments on liver and kidney histopathology in broiler chickens (P>0. 05). Liver in the body as a detoxifying organ absorbs a significant part of toxins produced from harmful microbes and external particles into the blood. However, it was not possible to remove them completely in the tissues because of high ability of nanoparticles in dispersion in tissues of broiler chickens (ZargaranEsfahani et al. 2010). Increased liver weight in the presence of nanoparticles due to inflammation in these organs has been reported in some studies. The results of this experiment didn’ t show any significant difference between treatments on liver and kidney histopathology in broiler chickens and there were no toxicological effects of silver nanoparticles on liver and kidney tissues (P>0. 05). Conclusion: Nanoparticles coated on zeolite and with organic acid can be used as an additive supplement without any adverse effect on feeding and histopathological liver and kidney in broiler chickens.

Introduction: Expressed Myostatin gene in the muscles is a member of the TGF-β family. It extends skeletal muscle and regulates the activity of muscle fibers. The Myostatin gene (GDF-8) works as a negative regulator of the skeletal muscle growth. Mutation in the Myostatin sequence changes its regulating function and results in the growth and hypertrophy of the muscles. Mutation in Myostatin has been found in various species. This gene has three exons and two introns in all species. Mutant alleles are significantly correlated with the growth rate and desired carcass traits and increase the ratio of muscle to fat and bone. Cross breeding is a common method of exploiting the genetic differences between different breeds and increasing the ability of individuals which is often considered as the quickest way to improve the sheep production efficiency. This study was conducted to investigate the effect of cross breeding on the Myostatin genes in Arabi lambs and its cross with Romanov. Materials and methods: At the beginning of the experiment, the similar ewes were artificially inseminated with Romanove ram sperm by laparoscopy method after estrous synchronization. Born lambs were kept in similar conditions. For this purpose, 16 Arabi and hybrid lambs were used in a completely randomized design with two treatments and eight replicates. After slaughter, the meat samples were immediately collected from right side of longissimus lumborum muscle and transferred to the lab in liquid nitrogen and stored at-80 ° C. RNA extraction was performed using the Trizol (Easy Blue) method. The quantity and quality of the extracted RNA were determined using a spectrophotometer (Thermo Scientific, Nanodrop, 2000C, USA) from 260 to 280 and 1% agarose gel (20 minutes at 100 volts). Total RNA quality was checked after extraction and used to produce cDNA. Synthesis of cDNA was made using the (Gene All) cDNA build kit in accordance with the manufacturer’ s instructions. The designing of the forward and reverse primers for the Myostatin gene and the reference one of Glyceraldehyde 3-phosphate dehydrogenase was performed using the Primer Quest program on the IDT site (Integrated DNA Technologies). Finally, the expression of Myostatin gene was evaluated by Real-time qPCR. Glyceraldehyde 3-phosphate dehydrogenase gene as housekeeping one was used to normalize the data. SAS and REST softwares were used to analyze the final weight and gene expression data, respectively. Results and discussion: cDNA synthesis was accomplished after extracting the RNA and measuring its purity. After the cDNA synthesis and dilution, the PCR reaction was performed. Following the successful replication of the desired fragments of Myostatin genes and Glyceraldehyd 3-phosphate dehydrogenase, the observation of the products in the agarose gel with the ladder confirmed the correctness of the fragments size. The size of the replicated fragments for the Myostatin and Glyceraldehyd 3-phosphate dehydrogenase genes are 81 and 144 bp, respectively. After ensuring the efficiency of the designed primers, the Real Time PCR reaction was performed in two replicates for each cDNA sample. The information obtained was sorted and analyzed. Results indicated that the highest mean of the target gene in Arabi breed and the lowest one in the crossbred group. The difference between the Arabi and crossbred group was significant (P<0. 05). The results indicated that the crossbreeding caused a significant reduction in the Myostatin gene expression. The expression of Myostatin gene in Arabi race was 1. 4 fold greater than that in the cross bred group. This was in concordance with the final lamb weights which were significantly different for the two groups. The final weight in the cross bred lambs were higher than the Arabi counterparts. Conclusion: Based on the obtained data, the current investigation was the first study in the field of Myostatin gene expression in Arabi×Romanove cross breeding. In overall, the results showed that the cross breeding can significantly affect the expression of the studied gene. Regarding the effect of Myostatin gene on the muscle function, decreased Myostatin gene expression may influence the final weight gain. As this study showed the effect of crossbreeding on Myostatin gene expression, it is necessary to consider the consequences of crossbreeding on the native sheep breeding programs. This study could help in more understanding the cross breeding effects on the livestock performance.

Introduction: Heat stress (HS) compromises efficient animal production and although difficult to accurately quantify, the economic impact on the global livestock industries is likely greater than $100 billion annually (Baumgard and Rhoads 2013). The economic decline in the dairy industry is primarily associated with lowered milk production, reduced growth, compromised milk quality, reduced reproduction, increased metabolic disorders and poor immune function. Dry matter intake per kilogram live weight was lower and the maintenance requirements of sheep were higher at high ambient temperatures (Marai et al. 2007). Pair-feeding study in dairy cows indicated that during heat stress, reduced dry matter intake accounted for only 35-50% of the decreased in milk production (Wheelock et al. 2009). A variety of amelioration strategies for HS are available and can be implemented alone or in a coordinated manner that include physical modifications to the environment, management adaptations, genetic selection, and dietary modifications. Nutritional strategies are among the easiest and cheapest to alleviate the negative effects of HS. Nutritional tactics used during HS generally focus on enhancing the energy density of the diet and decreasing the ration forage based on the reduction of incremental heat (Mahjoubi et al. 2016). Providing gluconeogenic substrates or supplements that metabolized into glucose precursors may increase productivity during the heat stress (Baumgard and Rhoads 2012). The objective of this study was to evaluate the heat stress effects and also glucogenic supplement during heat stress on performance, heat stress indices and blood metabolites of fattening Makoei lambs. Materials and methods: In this experiment, 10 male Makuei lambs with 3 months age and average live weight of 32 ± 3. 2 kg in 2 treatments and 5 repeat per treat at two experimental periods were used. 10 days before beginning of period 1, the lambs were adapted to 2×1 meter individual cage and experimental diets. Lambs received water and feed individually. Feed was delivered to the animals as a total mixed ration and offered in the morning (8: 00) and evening (16: 00). Diet was formulated to meet or exceed NRC (2007) recommendations (Table 1) using the Small Ruminant Nutrition System. In period 1 that lasted 10 d, lambs at thermal neutral (TN) condition (24. 5± 3. 2 ° C and temperature-humidity index [THI] of 66. 1 ± 2. 5) and heat stress (HS) (33-41° C and THI of more than 83) were fed ad libitum. In period 2 (lasted 10 d) the lambs of HS condition continued to ad libitum feeding and lambs in TN condition pair fed (feed intake reduced according to HS group feed intake in period 1) to eliminated the confounding effects of unequal nutrient intake. Both groups received 10 gr/d of a top-dressed glucogenic product (GL-Part 100 ® ) in two equal meals. All production and blood data were collected daily through both periods. Three thermostat-regulated heaters were used to generate the heat load and 2 fans were utilized to evenly distribute the heat load within the room and fans were angled to prevent hot air blowing directly on the animals. In the beginning of the experiment and at the end of each experimental period, lambs were weighed before morning feeding. During each period, DMI and water intake were recorded daily and body temperature indices were obtained at 1400 h. Blood samples were collected during both periods from the jugular vein (5 mL in collection tubes containing of sodium heparin) before and 4 h after morning feeding on d 3 and 8 in P1, and d 3, 8 in P2. Blood was centrifuged at 2000 x g for 15 min to obtain plasma and then, stored at-20° C for later analysis. Results and discussion: HS significantly reduced DMI in both periods than TN group (P<0. 05). Glucogenic supplement in period 2 significantly increased DMI than period 1 (P<0. 01). Glucogenic supplement increased average daily gain and feed efficiency significantly (P<0. 05). HS significantly increased rectal temperature in both periods, but Glucogenic supplement did not effect on body temperature. At a. m. feeding in both periods, blood glucose concentration of HS group significantly lower than TN lams (P<0. 05). After feeding, HS did not affect any of the blood parameters (Mahjoubi et al., 2016), But Glucogenic supplement affected NEFA blood concentration significantly (P<0. 05). Lower blood urea nitrogen in glucogenic supplementation treatments was probably due to a higher supply of glucose precursors and a less need for muscle tissue degradation to supply glucose precursors, leading to increased nitrogen efficiency (Donkin et al., 2009). After feeding, no increase in blood glucose after glucogenic supplementation was interesting because we expected that glucose precursor consumption would increase blood glucose concentration after feeding. The results differ on the effects of using glucose precursor supplements. Glucose precursor supplementation numerically increased blood insulin levels compared to the first period, which may be another reason for the lack of increased blood glucose in lambs after glucogenic supplementation. Differences in the type and composition of glucose precursor supplements, how much they are used in the diet and the physiological stages of livestock are the reasons for the differences in the results of different researchers. Conclusions: As expected, HS reduced DMI than TN lambs, but glucogenic supplemented lambs have more DMI than lambs in period 1. Dietary glucose precursors improved feed efficiency at HS. These results showed that in HS the efficiency of converting dietary nutrients into tissue accretion was enhanced as glucose precursors fed. Also, HS significantly increased rectal temperature in both periods. At a. m. feeding in both periods, blood glucose concentration of HS group significantly was lower than TN lams. But glucogenic supplementation significantly affected NEFA blood concentration. In overall, improvement of some important functional and metabolic indices in lambs fed with glucogenic supplement in HS condition can indicate the beneficial effects of this nutritional strategy on lambs during HS, but this needs more research to prove.

Introduction: Nowadays, acceptance of chicken meat as a healthy cheap meat resulted in massive consumption between consumers; consequently, higher production with higher quality and shelf life is of the main future goals of this industry (Morrissey et al. 1994). Poultry products and processing technology have become widely available and used worldwide, which leads to expanding competition in the meat production sector. Thus, success in poultry production is strongly associated with improvement in carcass growth and yield. It is mainly associated with an increase in the proportion of breast meat and a decrease in abdominal fat. While, high poly-unsaturated fatty acid content of the meat, make chicken meat prone to deteriorate during storage. So, any suggestion to achieve the industry targets including better growth performance, higher immunity condition, efficient gut function and higher meat quality is valuable. Antioxidants and antimicrobial agents are of feed additives for broiler diets that can enhance bird health and consequently can enhance food safety and quality (Cherian et al. 2013). But, because of international limitations on most antibiotic feed additives and global consumer concerns on the use of such additives, the poultry industry is looking for new alternatives with antimicrobial activities (Cherian et al. 2013). Efficacious, environmentally friendly and consumer favorable feed additives are necessary to poultry meat production. Many researches have been started on these alternatives and some of these alternatives include ionophores, prebiotics, synbiotics, acidifiers, organic acids, and nowadays medicinal plants and phytogenic. Recently, herbs or plant extracts with antioxidant capacity have received much attention. Also, the global demand for natural products from the poultry industry is rising. So, the industry has faced with popularity of using plant-based feed additives or phytogenics. Natural antioxidant compounds exist in these feed additives, can enhance lipid oxidative stability that results in better meat quality features (Aziza et al. 2010). Artemisia annua from the Asteraceae family is an annual weedy herb with global distribution originated. The herb is native to Asia and especially known as Qinghao in China, and now has become extensively distributed all over the world. The dried leaves of A. annua have been used in traditional medicine for treating malaria-infected patients (Torabi Goodarzi et al. 2006). Anticoccidial and antiparasitic effects of the Asteraceae family have been approved in poultry and ruminant nutrition, respectively (Brisibe et al. 2008). A sesquiterpene lactone called artemisinin is the main compound representing the antiparasitic effects of A. annua and contains an endoperoxide bridge. Besides, further 40 different bioactive compounds including, flavonoids, phenolics, purines, lipids, and other aliphatic compounds exist in A. annua leaves (Brisibe et al. 2009; Ferreira and Janick. 1994). So, the purpose of this study was to investigate the nutritional effects of different levels of Artemisia annua on performance, carcass composition and oxidative stability of Japanese quail meat. Material and methods: The research was conducted in the teaching and research farm of Gorgan University of Agricultural Sciences and Natural Resources, Faculty of Animal Sciences. The Artemisia annua plant was collected from around Gorgan in the late October and early November of 2018. The leaves of the plant were carefully separated and then, placed in a desiccator at 70 ° C for 48 hours. The dried leaves were powdered by electric grinding and kept in nylon in a closed package. A portion of the leaf powder was sent to the laboratory for analysis of its elements. To determine the effect of Artemisia annua on performance, carcass characteristics and oxidative stability of Japanese quail meat, a total of 375 Japanese quails were allocated in a completely randomized design with 5 treatments and 5 replicates (with 15 birds per each replicate). Birds were fed with zero, 0. 5, 1, 1. 5, and 2% Artemisia annua diet for 42 days. Diets were based on corn and soybean and were adjusted according to Poultry Nutrition Requirement Tables (NRC, 1994) using the UFFDA dietary software. In this study, growth performance (including weight gain, feed intake and feed conversion ratio) was calculated weekly. For this purpose, the feed intake was measured by subtracting the amount of feed left at the end of each week from the initial feed amount. Also, the mean birds weight of each replicate was subtracted from the mean weight at the beginning of the week and divided by the number of birds in that treatment in order to measure weekly weight gain. The feed conversion ratio was calculated by dividing the weight gain by feed intake. At 42 days of age, two birds were slaughtered from each pen to determine the carcass characteristics percentage (edible carcass, breast, thigh, liver and heart) and the malondialdehyde level in the breast and thigh tissues. Malondialdehyde was evaluated by the TBA method. All data were analyzed based on a completely randomized design by the GLM procedure of SAS (9. 2). Tukey multiple range test was used to study the differences between treatment means. Results and discussion: Weight gain was not affected by dietary treatments. Supplementing 2% of Artemisia annua in the quail’ s diet resulted in a significant decrease in feed intake during the last two weeks of production period (P<0. 05). Gholamrezaie Sani et al., (2013) reported that broilers that received a diet containing Artemisia annua leaf powder had less feed intake compared to the control treatment they linked the reduced feed intake to the high fiber of Artemisia annua. Feed conversion ratio was not affected by dietary treatments, too. Cherian et al. (2013) reported that quails that received diets containing 2 and 4 g/kg Artemisia annua had no significant difference in final body weight and weight gain with the control group. Also, Khalaji et al. (2011) reported that diets containing 1% Artemisia annua had no effect on final body weight and weight gain. Live weight as well as the weight of the breast, liver and heart were not different between treatments. The highest and the lowest carcass weight were observed in control and 2% Artemisia annua treatments, respectively (P<0. 05). Malondialdehyde concentration in treatments containing 1. 5% and 2% Artemisia were significantly different from other treatments (P<0. 05). According to the results of malondialdehyde concentration in thigh muscles, a significant difference between treatments was seen (P<0. 05). The highest level of malondialdehyde concentration in the thigh muscles was observed in chickens received control diet (0. 769 mg / kg) and the lowest level (0. 556 mg / kg) was seen in quails supplemented with 1. 5% Artemisia annua. Also, the highest concentration of malondialdehyde in breast muscles was observed in the control treatment (0. 961 mg / kg); while, the lowest level of malondialdehyde was seen in the breast muscles of chicks consumed diet containing 2% of Artemisia (0. 638 mg / kg). Conclusions: The results showed that feeding 2%of Artemisia annua in Japanese quail could increase their performance through reducing abdominal fat and increasing their meat quality by delaying in MDA production in thigh and breast muscles.

Introduction: Suckling calves rearing is the most crucial period for a dairy farmer because calves today will make the cows in the herd tomorrow. The success of the calf rearing period is the production of strong and healthy calves at weaning that continue well to their steady growth after weaning. Rumen of neonate calves is inactive and undeveloped and its stimulation to fast growth is of most importance. Volatile fatty acids including acetic acid, propionic acid and butyric acid are considering as main stimulators of rumen growth (Gorka et al., 2009). Acetate is primarily needed for peripheral energy, and in the adult cow part of it is incorporated into milk fat. Propionate is used to produce glucose in the liver. However, the role of butyrate for the ruminant is quite different. Butyric acid is one of the energy sources for rumen epithelial cells and has more stimulating effect (Heinrichs and Lesmeister, 2005). Butyrate inclusion in both milk replacer and solid feed has been shown to have beneficial effects on both intestinal development and animal growth in young livestock (Gorka et al., 2009). Enteric disorders in calves are associated with microbial dysbiosis in the gut, and thus the health-promoting effects of exogenous butyrate may be underpinned by modulation of the gastrointestinal microbiota. There is an evidence that encapsulated butyrate can reduce enteric pathogen colonization in swine and poultry and direct infusion of butyrate into the mature sheep rumen caused significant changes to the resident microbiota (Gorka et al., 2017). Based on this information, use of butyrate supplements in suckling calves nutrition was recommended to stimulate rumen epithelium growth. The aim of this study was to investigate the effects of microencapsulated sodium butyrate on performance, blood metabolites and nutrient digestibility of suckling Holstein calves. Materials and methods: For this experiment, 24 newly-born Holstein calves (average age 1-10 days, average weight 39± 4 kg) were used in a completely randomized design with three treatments and eight replications. The experimental treatments were: 1) Starter diet with no additive (control), 2) Starter diet with 5 g of sodium butyrate per day, 3) Starter diet with 15 g of microencapsulated sodium butyrate per day. Starter diet and water were available ad-libitum throughout the experiment. Calves were divided randomly among the experimental groups based on their birth weight to have similar average birth weight. Colostrum feeding was done by a nipple pail until three days of age and thereafter, milk feeding program was followed by feeding 4 kg whole milk from birth to d 14 in two meals, 6 kg milk from d 14 to 60 in two meals and 3 kg milk from d 60 til 65 in one meal and weaned at d 65. Milk was fed at 8: 00 and 18: 00 by bucket, and no refusal of the offered milk remained. Calves had free access to starter diet and water from d 7 of life and chopped alfalfa was included in the diet from d 20 of life at the rate 10 percent of starter diet. Individual pens, with 1×2. 5 m dimensions, that cleaned and bedded daily by fresh and dry straw were used for keeping the calves. For determination of growth performance throughout the experiment, calves were weighed biweekly on d 14, 28 and 42 of the experiment individually prior morning milk meal and the difference between two weighting was considered as weight change. Starter intake was determined from the difference between the offered feed and the refusal remainder the next day. Blood sampling were taken monthly (two times, on d 30 and 60) from jugular vein in two stage of all calves 4 hours after morning feeding. The collected blood samples were centrifuged at 3500×g for 15 min at 4° C and the obtained plasma and serum samples were freezed at-20° C till the analysis day. After thawing on room tempreture, the samples were analyzed to determine the concentration of glucose, total protein, albumin, glubolin, cholestrol, triglyceride, urea, aspartate aminotransferase, and betahydroxy butyrate. Apparent digestibility of nutrients including dry matter, organic matter, crude protein, ether extract and neutral detergent fiber was measured by using acid insoluble ash as external marker. Results and discussion: The results showed that the addition of microencapsulated sodium butyrate in starter diet of suckling calves had no effect on final body weight, starter intake and feed conversion ratio of calves. Calves fed 15 gr of microencapsulated sodium butyrate had significantly higher daily gain in the first month and total experiment period compared with control one (P<0. 05). There were no significant differences among the experimental treatments on average daily gain in the second month. The results showed that supplementing calves with butyrate supplements, encapsulated or common sodium butyrate did not influence blood concentrations of glucose, cholesterol, triglyceride, albumin, total protein, and blood urea at d 30 or 65 experiment; whereas, blood beta-hydroxy butyrate concentration was higher in calves fed microencapsulated form compared with control calves (P <0. 05). Feeding butyrate supplements had no effects on digestibility of dry matter, organic matter, crude fat and neutral detergent fiber. Protein digestibility increased significantly by feeding the microencapsulated form of sodium butyrate compared with the control (P <0. 05). Gorka et al. (2009) reported that use of butyrate in starter feed of calves had not significant effect on body weight gain. Ferreira and Bittar (2011) reported that blood betahydroxy butyrate concentration was not affected by addition butyrate supplementation. Deymeh et al. (2014) reported that supplementing starter diet of calves with butyrate causing improve protein digestibility. Guilloteau et al. (2010) reported that feeding butyrate supplement in milk replacer improves pankreas function and nutrient dugestibility. Zabielski et al. (2008) stated that feeding butyrate to suckling calves increased the length of intestinal papillae. Rearing suckling calves is one of the most important management programs in dairy cow farms and use of good and precise nutritional strategies is of importance for growth and health of calves. Application of feed additives is one of these nutritional tools. The results of this study proposed that the addition of microencapsulated sodium butyrate, compared with common sodium butyrate, based on its positive effects on performance and nutrient digestibility and blood beta-hydroxy butyrate concentration, can be recommended in rearing suckling calves.

Introduction: Subacute acidosis is characterized by pH of 5. 5 and below, reduced feed intake and livestock performance, and leads to significant economic losses. Therefore, preventive measures to prevent the occurrence of acidosis and improved digestion of starch such as probiotics and buffers have been considered. The feeding of high fermentable carbohydrates in ruminants resulted in producing high amounts of organic acids in the rumen, followed by a decrease in rumen pH. In the animals not adapted to high levels of carbohydrate fermentation, rumen lactate concentrations increase unacceptably, because populations of lactate-utilizing bacteria such as Selenomonas ruminantium and Megasphaera elsdenii are low and cannot rapidly match and their proliferation need more time (Chaucheyras-Durand et al. 2008). Reports show that the consumption of live yeast cells of Saccharomyces cerevisiae leads to the removal and consumption of oxygen in the rumen environment as well as the release of some essential enzymes, vitamins and other nutrients. These factors can significantly contribute to the proper life and activity of microorganisms in the ruminal environment. It has been suggested that the yeast of Saccharomyces cerevisiae may develop the population of Megasphaera elsdenii and increase lactate use (Calsamiglia et al. 2012). Megasphaera elsdenii prevents the sharp decrease in ruminal pH by consuming lactic acid as a result of lactic acid accumulation (Perbo et al. 2012). Due to the diverse ability of different species of Megasphaera elsdenii to produce volatile fatty acids under acidosis, further research can help find new species with high ability to use lactate (Sedighi and Alipour 2019). The use of yeast and bioactive compounds compared with the chemicals can be effective in reducing inflammation caused by acidosis (Aschenbach et al 2019). Material and methods: Twenty-four Arabic male lambs with four months old and initial body weight of 23. 9± 3. 15 kg were used in a completely randomized design with three treatments and eight replicates. The trial period consisted of 77 days (11 weeks) including 14 days of habituation period and 63 days (9 weeks) of recording period. The lambs were randomly assigned to one of the three treatments: 1-control (no additive) 2-control + Sodium bicarbonate (1% daily diet in two meals) 3control + Megasphaera elsdenii and Saccharomyces cerevisiae (bacterial-yeast). The amount of Megasphaera elsdenii was 3 ml per animal (4. 5 × 10 8 cfu / ml) plus 2 g of Saccharomyces cerevisiae 9 (7 × 10 cfu/g) (DFM) fed to the animals daily in the morning (Sedighi and Alipour 2019). The diets were adjusted using the Small Ruminants Nutrition Requirements (NRC 2007). The lambs were fed a fully mixed (TMR) ratio of 30% forage and 70% concentrate at two meals (8 and 16 hours) with free access to water. Ruminal fluid was taken by stomach tube at 0, 3 and 6 hours after morning feeding to measure pH and ammonia nitrogen (NH3-N) concentration. The ruminal fluid was analyzed for ammonia-N using a phenol-hypochlorite method (Broderick and Kang 1980). On the last day of the experiment, rumen fluid was taken to measure the concentration of volatile fatty acids (5 ml of rumen fluid with 2 ml of 25% acid metaphosphoric acid (W/V) was mixed and stored at-20 ° C until analysis). Blood sampling was taken from each lamb within 3 h after the morning feeding from the jugular vein by using EDTA as an anticoagulant. Blood samples were analysed for glucose, blood urea nitrogen (BUN), total protein, cholesterol, triglycerides, LDL, HDL, creatinine and liver enzymes including aspartate amino transaminase (AST) and alanine aminotransferase (ALT). During the last seven days of the period, total faeces and urine samples were collected to determine digestibility and nitrogen retention. Results and discussion: No differences were observed between treatments in dry matter intake (DMI), daily weight gain (ADG), feed conversion ratio, pH and ammonia nitrogen (NH3 – N) (P>0. 05). In the first 21 days of the experiment, body weight gain and average daily gain in the bacterial-yeast recipient treatment were significantly higher than the control (P <0. 05). Observing a lower concentration of ammonia nitrogen at 3 o'clock than 6 o'clock after feed intake is the result of better use of ammonia nitrogen in the rumen due to the greater supply of carbohydrates available in the rumen. Propionate concentration was higher in the bacteria-yeast treatment than other treatments (P <0. 05). Megasphaera elsdenii is the only known rumen microorganism that can convert lactate to propionate by the acrylate pathway; when the lactate concentration increases, which produces propionate and acetate and sometimes butyrate from it (Prabhu et al. 2012). The concentrations of butyrate, isobutyrate, isovalerate and rumen valerate in the bacterial-yeast recipient treatment and bicarbonate buffer was lower than the control treatment (P <0. 05). The production of branched-chain fatty acids (such as isobutyrate, isovalerate, and valerate) has been shown to be the result of the activity of amylolytic bacteria (Zhang et al. 2017). Protein digestibility was higher in control and bacteria-yeast treatments than in buffer treatment (P <0. 05). Low-density lipoprotein (LDL) was lower in buffer and bacteria-yeast treatments than in control treatment (P <0. 05). Nitrogen retention was higher in the bacteria-yeast treatment than in the other treatments (P <0. 05). Significance of nitrogen retention in the bacterial-yeast recipient treatment can be attributed to the decrease in ruminal ammonia nitrogen concentration, which appears to be due to increased nitrogen incorporation in the microbial protein, which is a logical consequence of increased rumen microbial activity (Paryad and Rashidi 2009). Liver factors that are considered as an indicator of liver health were numerically lower in treatments containing buffer or bacterial-yeast. Conclusion: The use of acid-consuming bacteria can be an effective way to modify rumen fermentation conditions of lambs fed with high concentrate diets. In the present experiment, the effect of acid-consuming bacteria was competitive with the sodium bicarbonate chemical buffer on nutrient digestion and growth performance. Results from volatile fatty acids showed that bacteria-yeast treatments by leading the fermentation pathway to convert lactate to propionate could be beneficial for livestock health and its economic longevity.

Introduction: Silkworm (Bombyx mori) is an important economic insect which is used as experimental material for the evolution of economically important silkworm breeds. Breeds/strains thus evolved are maintained in germplasm stations for breeders and researchers to use (Chiang 1980). Silkworm germplasm resources have a very important role not only for use in sericulture and silkworm breeding, but also for experimentation in genetics and molecular biology research. Based on several parameters like nutrition, genetics, and biochemistry, silkworms have been classified into different inbred strains (ESCAP 1993). However, few studies are reported for classification of silkworm based on larval growth potential. The Islamic Republic of Iran has valuable silkworm genetic resources which differ in cocoon shape. The present study was carried out to evaluate and identify oval cocoon bivoltine breeds suitable for rearing as germplasm resources under climatic conditions in Iran. Material and method: The present study was conducted in the Iran Silkworm Research Center (ISRC) and Islamic Azad University, Qaemshahr Branch, Iran. Fifty-four oval cocoon strains maintained by the Iran Silk Research Station (ISRC) were analyzed for the estimation of evaluation index to study their genetic divergence. Silkworm rearing was carried out as a single batch rearing system. Disease free laying of these strains were incubated in a controlled environmental chamber. When the eggs attained the head pigmentation stage on the 8 th day of development, they were shaded with a black gobo for 48 hr to shield them from light, so as to obtain uniform hatching on the 10 th day. Neonates were brushed and reared separately on fresh mulberry (Morus alba) leaves. st Young 1 rd to 3 instar larvae were reared at 27– 28° C and 85-90% relative humidity. Late age larvae th viz., 4 th and 5 instars, were reared at 24-26° C and 70-80% relative humidity. The larvae were fed mulberry leaves ad libitum three times a day. 250 larvae each from all batches of all strains were retained for completion of the life cycle. Feeding and other conditions of larval rearing were conducted following standard procedures. Larval growth weight was recorded on day 1, 3, and 5 of th the 5 instar (3 replicates each), using a precision digital balance. Evaluation index and subordinate function values were calculated for performance indices based on changes in larval weight at the last larval instar. The Evaluation index and sub-ordinate function values for all traits were calculated separately and average index value was obtained. Silkworm strains were ranked based on the average of evaluation index method and sub-ordinate function method. Hierarchical agglomerative clustering was done by using NTSYS-pc, version 2. 02e based on complete, single, UPGMA, UPGMC, and FLEXI approaches, and SAS-pc based on WARD and average approaches. However, the method of average linkage between groups (Romesburg 1984) under UPGMA (Unweighted Pair-Group Method using Arithmetic average) was considered as the major and final protocol for data conclusions and the resulting clusters were expressed as dendrograms. Results and discussion: ANOVA based on a completely randomized design indicated significant variations among the silkworm strains (P<0. 01). On the fifth day, strains 104×110, Shown, 102[Shown], 124-16-9[116] and Shaki A×D had significantly higher larval weights ranging from 4. 153– 3. 965 g (P<0. 01). Larval growth parameters revealed higher evaluation index and higher sub-ordinate function values for strains 104×110 (197. 272 and 2. 857), 1001 (193. 268 and 2. 780), BH-4 (186. 365 and 2. 647), 124-16-9[116] (183. 023 and 2. 602), and Shown (180. 744 and 2. 556). In the present study, by adopting quantitative approaches, 54 silkworm oval strains with different geographical distribution were analyzed. Based on these results it was observed that strains of the same origin did not group together, indicating they have different biological background. Main groups were divided into various sub-groups. Some oval strains were grouped together and were placed far away from other silkworm strains, indicating they might be suitable for future crossing, maintenance of parental strains, and hybridization with peanut cocoon strains so as to maximize heterosis and to avoid inbreeding depression. Because of the low effective population size and each female mating only with one male (thus, all her offspring were full-sibs), the inbreeding rate for this study was very high. This could cause more differentiation among these strains. The grouping methods allowed us to subdivide observations into several subgroups in such a way that we obtained homogeneity inside the subgroups and heterogeneity between the subgroups. Present results confirmed and complemented the results of previous studies about the importance of evaluation and classification of Iranian silkworm strains based on economical and biological characters (Zhao et al. 2007; Zanatta et al. 2009). Silkworm oval strains could be clustered into different groups according to the geographic areas initially observed. Present results confirmed and complemented the results of previous studies about the importance of evaluation and classification of Iranian silkworm strains based on economical and biological characters (Sohn 2003). During selection of two parents for hybridization, some characters should be matched, including high silk yield, adversity-resistance, good combining ability, and excellent silk quality, so that hybrids have good characters of both parents. Effective utilization of selected germplasm plays an important role in saving time in the synthesis of new hybrids. Critical assessment of variability present in the breeding material is a pre-requisite for paving the way of combining most of the desirable traits present in different genotypes into a single hybrid combination. Generally, hybrids from distant background have high heterosis. The study of diversity is important for selection of useful races, use of the heterosis advantage and generating new races. The selection of high yielding breeds with wider adaptation and stable performance are important goals in breeding programs.