نشریه پژوهش های علوم دامی
سال سی و دوم شماره 4 (زمستان 1401)

Organic acids are compounds that can be considered as a replacement for antibiotics. Butyric acid is known as the main stimulant of intestinal wall tissue and modulator of normal intestinal microflora (Van Immerseel et al. 2004). Butyric acid is also the main source of energy for intestinal cells and is essential for the development of gastrointestinal-related lymphoid tissue (Friedman and Bar-shira, 2005). The positive and beneficial effect of butyric acid on the functional traits of broilers has been reported (Leeson et al. 2005; Antongiovanni et al. 2007). Butyric acid is a highly volatile and highly smelling compound, much of which is absorbed at the beginning of the gastrointestinal tract (Bolton and Dewar, 1965). The effects of butyric acid appear to improve if it is protected from absorption in the upper gastrointestinal tract (Leeson et al. 2005). For this purpose, butyric acid glyceride along with butyrate-calcium was used in this study. Calcium butyrate is a protected form of butyric acid that is produced using a new technology by Kimia Daroo Mehr Company in Tehran, Iran. This product passes intact through the gut and after decomposition by the pancreatic lipase is absorbed in all different parts of the intestine. Calcium butyrate is a bio-odorless substance and contains 70% butyric acid. butyric acid glyceride (C4) is the brand name of butyroglycerol (Sanadam Pars, Tehran, Iran). Butyric acid is esterified with a glycerol molecule and the resulting compound has a very stable structure. After consumption by animal, pancreatic lipase, it is broken down to the constituents and is absorbed. The aim of this experiment was to investigate the effects of different dietary supplementation levels of calcium butyrate, butyric acid glyceride and their mix on growth performance, carcass traits and jejunal morphology in broiler chickens. A total of 400 one-d-old broilers from Ross 308 strain were allotted to 10 dietary treatments, 5 replicates and 10 broiler chicks per each, from 1 to 42 days of age. Experimental diets included: control (without additives), and supplementation of calcium butyrate (0.15, 0.30 and 0.45% of diet), butyric acid glyceride (C4) powder (0.15, 0.30 and 0.45% of diet), and three levels of calcium butyrate and C4 powder mixture in equal proportion (0.075+0.075, 0.15+0.15, and 0.225+0.225% of diet). Light was provided as 23 h light and 3 h darkness. Rearing house temperature was set at 32°C on day one, and then decreased by 3°C per weak to reach 21±2 °C and remained constant until the end of the experiment. During the experimental period, feed and water were provided ad libitum. Mortality were collected, weighed and recorded daily. At the end of each period, the amount of feed consumed and the group weight of the chickens in each pen were recorded and feed conversion ratio was calculated after adjusting for dead birds. In order to evaluate the morphology of the small intestine at the age of 24 days, one chick per pen close to average pen weight was selected and slaughtered. About one centimeter was removed from the middle part of the jejunm tissue and placed in 10% formalin solution and sent to the laboratory. At the end of the rearing period (42 days), after weighing the chickens, one chick was selected from each replication and slaughtered to measure carcass traits. Data were analyzed in a completely randomized design using General Linear Model procedure by SAS (2009) statistical software. The treatments mean was compared using Duncan's multiple range test at P < 5 %. The average body weight of chicks at the age of 10 days and the mean daily weight gain of 1-10 days in the groups receiving the mixed powder C4 and calcium butyrate (0.225+0.225% of diet) was significantly higher than the control group (P< 0.05). However, the effect of experimental treatments on body weight at 24,42 days of age, and the weight gain at 11-24, 25-4, and 42-1 days of age was not significant (P> 0.05). The feed conversion ratio (FCR) at the age of 1-10 and 1-42 days in control treatment was significantly higher than other treatments (P <0.05). Treatment with mixed powder c4 and calcium butyrate (0.225+0.225% of diet) had the highest relative hepatic weight and lowest abdominal fat weight compared to other treatments (P<0.05). Regarding to the morphological traits of the small intestine, the highest thickness of the muscle layer was observed in the control treatment (P<0.05). Iincreasing villus length can be attributed to the reduction of pathogenic bacteria. Increasing the length of villus increases the digestibility and absorption capacity of nutrients, and since this increase in jujumen, which is the main source of digestion and absorption of nutrients in birds, can be concluded that it is likely the use of organic acids can have beneficial effects on the digestion and absorption of food and subsequently the performance of the birds. In this study the thickness of the muscle layer in the treatment of organic acid intake was reduced, it can be concluded that the use of organic acid supplementation with the effects on the pH gastrointestinal tract probably reduced the pathogenic bacteria in the intestine. By reducing the number of pathogenic bacteria in the intestine and making it healthier, it requires a thinner epithelium to protect the surface of the intestine, which is likely to result in a thickening of the muscle layer thinner. Given that most of the additives that have been introduced as growth promoters have been shown to have an impact on the performance of broiler chickens due to antimicrobial activity and the effect on the microbial flora of the digestive tract. Therefore, breeding conditions and the rate of infection of birds with pathogenic bacteria in the test can be as a result of the test. Each of these additives has different levels of compounds and levels, the dosage and the ingredients used in the experiment can also be effective in the various results obtained from using these growth stimulating agents. In general, the results of this experiment showed that the addition of butyrate-calcium and glyceryl butyric acid to the diet alone or combined with each other, with a positive effect on digestion and absorption of nutrients, could improve the growth performance, some carcasses components and Morphology of small intestine of broiler chicks. The difference in the results of the research may be related to the different buffering capacity of the experimental diets or the type and amount of organic acids used in the experiments.

A study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical techniqueAbstract While the physiological conditions of most animals are reflected in their body fluids, in dairy cows physiological conditions are reflected in milk combinations. When negative energy balance occur, production that caused body fat store destruction, goes in two major metabolic ways in liver and breast tissues. In breast tissues, free fatty acids increase fat to protein ratio and in liver, free fatty acid change metabolism leading to increase of ketone bodies. Lactation persistency in dairy cows is one of inheritable economic trait and important characteristic of the lactation curve. The change of this trait is under control of different factors such as animal genetics structure. The amount of cow production at the peak of milk production depends on the calving physical condition, genetics, the absence of infectious and metabolic diseases, and postpartum diet. Fat to protein ratio in early lactation is associated with performance during lactation. Fat to protein ratio is also correlated with some diseases such as retained placenta, displacement of abomasum, metritis, endometritis, mastitis and culling. Fat to protein ratio (FPR) in test day milk records is a good indicator for body fat metabolism and the level of negative energy balance, and that it could be used as a selection criterion to improve metabolic stability. Quantile regression has not been widely used for modeling of biologic characteristics of livestock and this research aimed to evaluate the shape of fat percentage, protein percentage and FPR in test day milk records of Iranian dairy cows using a polynomial quantile regression model. The data used in this study were provided by the Animal Breeding Centre, Iran. Initial data set were edited by Excel and Foxpro software. The traits under consideration were fat percentage, protein percentage and fat to protein ratio (calculated based on the magnitude of the first two traits). All cows had value for all traits. Final data comprised a total of 784,532 test day records collected from 93,259 first-parity dairy cows (progeny of 2741 sires and 79843 dams) distributed in 660 herds over the country and calved between 2003 and 2013. In the data, test day fat percentage and protein percentage had a minimum of 1 and 1.5 and a maximum of 7 and 7, respectively. By SPSS software, some statistical characteristics of the traits were calculated, and by SAS software a quadratic polynomial quantile regression model (in the range of quantiles 5 to 95) was fitted to the data. Based upon the fitted model, linear and quadratic regression coefficients were estimated for the effect of day of lactation on each trait in different quantiles. In the model, traits and day of lactation were response and independent variables, respectively. Quadratic effect of day of lactation is considered due to nonlinear variation of the traits over the course of the lactation curve. Mean fat percentage, protein percentage and fat to protein ratio over the lactation course were found to be 3.35%, 3.08% and 1.1, respectively. As expected, for each trait a nonlinear change was observed over the lactation period. The highest content fat to protein ratio occurs in the early period of lactation and the lowest was observed in the sixth and seventh months of lactation. In terms of absolute values, minimum (953.564) and maximum (1797.661) linear regression coefficient of days in milk were obtained in quantiles 5 and 95, respectively. The same trend was also observed for quadratic regression coefficient of days in milk. Linear and quadratic regression coefficients of fat and protein percentages ranged over different quantiles so that minimum and maximum absolute values were observed in quantiles 5 and 95, respectively. Quantile regression model is an appropriated statistical technique for evaluate the effects of an independent factor which differently affects the shape of a response variable. In this research, the effect of days in milk on three traits (fat and protein percentage, as well as fat to protein ratio) was modeled by quantile regression. The findings of the present research indicate that the curve shape of fat percentage, protein percentage and fat to protein ratio are different for the quantiles suggesting that these differences are needed to be taken into account in nutrition management and cattle breeding scheme.Keywords: Dairy cow, Modeling, Quantile regression, Ratio of milk compositionA study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical techniqueA study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical techniqueA study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical techniqueA study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical techniqueA study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical techniqueA study on the curve of far percentage, protein percentage and fat to protein ratio in test day milk records of Iranian dairy cows using quantile regression statistical technique

Many outbreaks of foot and mouth disease (FMD), an endemic disease of artiodactyl ruminants, occur all over the country every year. FMD is one of the diseases that cause a lot of economic damage to animals and is one of the main obstacles in ensuring health and production of livestock. Preventing the introduction of the disease into a country by controlling the imports of meats and meat products and other sources which might transmit the virus or use of vaccination are two major alternatives in respect to preventing and controlling FMD (Carpenter and Thieme, 1979). Vaccination, with currently available and tested vaccine must be undertaken at least three times annually to maintain immunity. The semen quality may be affected by vaccination due to vaccine stress and anaphylactic shock (Murugavel et al. 1997). The present investigation was carried out to study the effect of FMD vaccination on seminal traits of Holstein bulls.

Twenty Holstein bulls between three and five years old maintained at Nahadehaye Dami Jahed Artificial Insemination center were used in present study, which were housed in individual pens under identical feeding and management regimes. FMD vaccine polyvalent (inactivated, containing virus types O2016, A13, A15 and Asia1 strains) produced by Razi vaccine and serum research Institute was administered for vaccination purpose at 5 ml by SC injection route. Semen samples were collected by artificial vagina technique. Appropriate sexual preparation with two false mount on dummy cow was followed. A total of 571 semen ejaculates were collected at 15 days before, 15 days after and 15-30 days after FMD vaccination during autumn of 2018 and spring of 2019. Seminal traits like fresh and post thaw sperm motility, motility after incubation test, sperm concentration, semen volume and HOS test were evaluated. The ejaculate volume was measured in the divided semen collection tube in milliliters. The concentration of spermatozoa was calculated by photometer. Motility of spermatozoa was analyzed by Computer-assisted sperm analysis (CASA). The integrity of sperm membrane was evaluated using the hypo-osmotic swelling test (HOST). Extended semen was filled in medium straws and were frozen by programmable freezing device. Recorded data were analyzed using SPSS, oneway ANOVA. The differences at P<0.05 were considered to be statistically significant.

However, the available reports on the effect of such vaccination on semen quality are conflicting, Vaccination is one of the major anaphylactic stress factors that affect the semen quality (Gahlot and Kohli, 1981; Venkatareddy et al. 1991 and Murugavel et al. 1997).In this study There was no significant (P>0.05) effect of vaccination on the semen volume in Holstein bulls, but a slightly increasing trend was observed. The secondary activities of accessory sex glands remain unaffected following vaccination (Radhakrishnan et al. 1975). So, this can be considered as a possible cause for no change in the ejaculate volume. However, Venkatareddy et al. (1991) in Onqole, Jersey and Ongole × Jersey breeds reported an increase in the volume of semen. Significant decrease in sperm concentration following vaccination was observed by Venkataswamy and Rao (1970); Venkatareddy et al. (1991) and Singh et al. (2003). On the contrary, Kammar and Gnagadhar (1998) reported no adverse effect of vaccination on sperm concentration during post vaccination period, and in the current study there is no evidence of reduction in sperm concentration (p>0.05). The decreased sperm concentration may be due to the adverse effects of therapeutic agents on germinal cells resulting into increase in dead spermatozoa, which are absorbed by leucocytes through phagocytosis (Mann and Mann 1981). The negative effects of vaccination may be due to the adverse effects produced by therapeutic agents or degenerative changes in germinal epithelium. The increased resorption of abnormal spermatozoa leads to reduction in epididymal sperm reserves (Rao et al. 1980), thereby decreasing concentration. The motility of sperm cell develops during their passage through epididymis (Olson et al. 2002). However, vaccination transitory rise in body temperature as well as testes temperature causes derangement in spermatogenesis and epididymal function, and this leads to vaccination mediated declined sperm motility (Arthur 1989). When testicular temperature increases, metabolism increases at a greater rate than blood flow and hence the testes become hypoxic. Therefore, the testes are very susceptible to temperature increases due to endogenous or exogenous factors (e.g. fever, high ambient temperature). As testicular temperature increases, the proportion of defective spermatozoa increases; recovery is dependent upon the nature and duration of the thermal insult (Setchell 1978). Pankaj et al. (2007) reported significant reduction in the mass activity and motility of buffalo bull semen after vaccination. In this study a non-significant effect on initial progressive motility with decreasing trend was observed which is in agreement with observation of Gupta et al. (2017). Our results are in agreement with the findings of Bhakat et al. (2010) who reported a significant decline in post thaw motility during post vaccination. To be specific, there was a significant decrease in frozen semen samples progressive and slow motility, rate of plasma membrane integrity and significant increase in immotile spermatozoa in our study(p<0.05). Contrary to this Mangurkar et al. (2000) observed no significant effect on post freezing motility. Both physiological and structural status of sperm get severely affected during cryopreservation (Bailey et al. 2003). The chemical, osmotic, thermal and mechanical stresses during extension, cooling, freezing and thawing result in cryoinjuries of varying degree to the spermatozoa (Farooq et al. 2013). The significant variation in post thaw motility and motility after incubation test can be attributed to the effect of thermal stress developed following vaccination (Gupta et al. 2017).

The observations showed that vaccination changes the seminal characteristics of Holstein bulls. Thus, it is suggested that AI Centers consider sexual rest and prescribe supportive treatment in order to improve semen characteristics after vaccination.

Sheep and goat meat is considered as one of the main sources of red meat in Iran. Lori-Bakhtiari sheep is one of the most important breeds among the native sheep breeds in Iran with a large population and acceptable meat quality and also adaptability to poor ranges. Weaning lambs is the removal of a milk-based diet, either provided by the ewe or milk replacement in a hand-rearing system, onto forage or grain-based diet. As with any management practice such as a change of diet or significant social change for the animal, the period may be stressful and careful management is essential. The time of weaning is very important in lambs since it affects feed consumption; growth performance and carcass characteristics of lambs. Range sheep operations traditionally have allowed lambs to graze with their dams until late spring or early summer. This poses a problem when severe drought conditions and forage availability is limited. Early weaning can provide some very appealing benefits: More pasture will be available to maintain the retained ewe flock if lambs and cull ewes are removed earlier in the year; The ewe’s nutrient requirements are reduced after weaning, which will cause ewes on pasture to eat less and lose less weight; Lambs use supplemental feed more efficiently for growth than ewes use it for milk production; Placing lambs in a feedlot will reduce predator losses. This study was conducted to investigate the effects of weaning age and rearing type on the growth performance of Lori-Bakhtiari male and female lambs. 150 Lori-Bakhtiari ewes were synchronized during the mating season and then randomly mated with Lori Bakhtiari rams. A total of 110 ewes gave birth in the lambing season with a range of 10 days, of which 113 healthy lambs (59 male lambs and 54 female lambs) were selected and studied at two months of age. The experiment was conducted in a completely randomized design. Male lambs were divided into six treatments including early-weaned fattening lambs (10 heads), early-weaned non-fattening lambs (10 heads), traditional weaned fattening lambs (10 heads), traditional weaned non-fattening lambs (8 heads), late weaned fattening lambs (10 heads) and late weaned non-fattening lambs (11 heads), and Female lambs were studied in three treatments including early weaning (17 heads), traditional weaning (20 heads) and late weaning (17 heads). Weaning of lambs in early weaning, normal weaning, and late weaning was performed at the mean age of two months, three months, and four months, respectively. The fattening of male lambs continued until the age of six months. Other non-fattened weaned lambs (male and female) were raised with their dams up to six months of age without access to the mother's breast. Lambs had access to dry forage (in winter) and wet forage (in spring and summer) in addition to milk before weaning. At birth, the weight of all lambs was measured and the sex and type of birth (single and twin) of lambs were recorded. The weight of all lambs was measured and recorded at two months and then monthly up to six months. Daily weight gain in monthly periods and final weight gain in lambs of different treatments were calculated. Data were statistically analyzed by SAS software and MIXED procedure. At three months of age, early-weaned fattening lambs were heavier than the lambs of other treatments (P<0.05). At four months of age, early-weaned fattening lambs weighed more than traditional weaned fattening lambs and traditionally weaned fattening lambs weighed more than male lambs in other treatments (P<0.05). At this age, the weight of male lambs in traditionally weaned non-fattening, late-weaned fattening, and late weaned non-fattening treatments was not statistically significant. Also, in five-month-old male lambs, the weight of early-weaned fattening lambs was higher than the lambs of other treatments (P<0.05). The five-month weight difference of lambs was not significant in non-fattening treatments. At six months of age, early-weaned fattening lambs weighed more than traditional weaned fattening lambs, and traditionally weaned fattening lambs weighed more than male lambs in other treatments (P<0.05). In general, at six months of age, fattening lambs weighed more than non-fattening lambs (P<0.05). There was no statistically significant difference in the weights of lambs of non-fattening treatments at the age of six months.In male lambs, early-weaned fattening lambs from two to three months of age gained 293 g / day, which was significantly higher than the lambs of other treatments in the same period (P<0.01). The average daily weight gain in male lambs from three to four months of age was higher in early-weaned and traditional weaned fattening treatments than in other treatments (P<0.01). In males and from two to six months of age, the mean daily weight gain in early-weaned fattening, traditionally weaned fattening, and late weaned fattening treatments was 242, 226, and 212 g / day, respectively, and the difference between early-weaned fattening and late weaned fattening treatments was significant (P<0.01). During these four months, the average daily weight gain was equal in the non-fattening treatments. During the same period, the mean daily weight gain in fattening lambs was higher than the average daily weight gain in non-fattening lambs (P<0.01).There was no statistically significant difference between female lambs in different treatments for weight at the same age. Also, there were no significant differences in terms of average daily gain in the rearing period between female lambs in different treatments. Data obtained in this study indicated that weaning of male lambs at two months of age and fattening them until six months of age had positive effects on their growth and final weight and weaning of female lambs at two months of age hadn’t a negative effect on their weight gain until six months of age.

Increased concerns about antibiotic resistance due to increased growth-promoting antibiotic inclusion in animal feed over the therapeutic dosage have been made scientists look for a proper alternative with similar benefits and without negative impacts on animal and human communities. Pennyroyal (Mentha pulegium L.) has been considered as a possible alternative for both antibiotics and synthetic antioxidants (Mohammadi, 2020). Although few studies have investigated the effects of this herbal plant on the production performance of laying hens and quality traits of eggs stored under different environmental conditions and storage times (Nobakht et al., 2011, Paymard et al., 2013), previous studies have been reported confusing information in this case (Aydın and Bölükbaşı, 2020). Most of these studies have reported reduced egg production due to the supplementation of pennyroyal powder to laying hens’ diet. Also, it has been reported that pennyroyal supplementation has less or no impact on egg quality traits. However, it has been suggested that pennyroyal might have strong antioxidant properties due to its composition of essential oils and/or phenolic compounds, such as pulegone as a dominant compound, which may affect the quality traits of eggs, especially those stored for a long period of time (Ruberto and Baratta, 2000). Therefore, the present study was designed to evaluate the effects of different levels of pennyroyal supplementation on the performance and egg quality traits of old laying hens that are highly prone to oxidative stress. In this experiment, one-hundred and twenty laying hens (Hy-line W36) with 53 weeks of age were provided farm the nearest commercial layer farm and distributed in three treatments, four replicate and eight birds per replicate with similar body weights (±5%) on a completely randomized design. Experimental treatments include 1) control diet (without pennyroyal supplementation), 2) 0.5%, and 3) 1% pennyroyal supplementation. In this study, two weeks were considered as an adaptation period and the birds fed with the control diet. The experiment lasted for eight weeks and birds fed the experimental treatments. The aerial parts of the pennyroyal were purchased fresh from a local store in West Azerbaijan, and their essential oil contents were measured by GC-mass spectrometry after air-drying and grinding. Chemical composition analysis has indicated that pulegone was the dominant component of the pennyroyal powder used in this study (17.11%). The present study consisted of two experiments; the first one for evaluating the production performance and egg quality traits, and the second one for evaluating the internal quality traits of the eggs stored under different storage times (7 or 30 days) and temperatures (4 or 25°C). Experimental diets based on the corn-soybean meal were formulated according to the nutritional recommendations of the Hy-line W36 strain and fed for eight weeks. The egg numbers and mean egg weight were recorded daily, and the feed conversion ratio, feed intake, and egg mass were calculated weekly. Two eggs were collected from each replicate to evaluate their quality traits at both experiments. Serum samples were obtained by blood sampling from the wings vein to evaluate serum biochemical parameters. The results of the present study indicated that pennyroyal supplementation has significantly reduced egg production and egg mass, and increased FCR (P<0.05). These findings are in agreement with the previous studies (Arjomandi et al., 2011, Nobakht et al., 2011, Paymard et al., 2013). According to the findings of the present study and previous investigations, the negative impacts of the pennyroyal supplementation might be due to the high content of pulegone (in this study 17.11%), which converts to menthofuran (a hepatotoxic composition) after being metabolized. Furthermore, pennyroyal supplementation significantly reduced the Haugh unit and increased albumen pH (P<0.05). These findings were in agreement with the study of Paymard et al. (2013) and disagreement with the other studies (Arjomandi et al., 2011, Nobakht et al., 2011); Since they have seen no impact of pennyroyal supplementation of egg quality traits. The probable reason for these negative impacts might be explained by the previous studies that investigated the other antioxidant alternatives, which have stated that polyphenolic compounds or essential oils of herbal plants could increase the albumen pH and therefore weakens the protein bonds between lysozyme and ovomucin of albumen (Ahn et al., 1999, Arpášová et al., 2014). Evaluation of the internal quality traits of the eggs stored under different times and temperatures indicated that the main effects of pennyroyal supplementation were not significant in desired parameters; however, the main effects of times on HU and ApH, and the main effects of different temperatures on YI, HU, ApH, and YH were significant (P<0.05). Additionally, significant interactions existed between pennyroyal levels and storage times in HU, YI, and YH (P<0.05). Also, Significant interactions were reported between pennyroyal levels and storage temperatures in ApH and YpH (P<0.05). Furthermore, significant interactions existed between storage times and temperatures in HU and YP (P<0.05). Though, no significant interactions were reported between all three factors. Almost no study has been conducted to evaluate the effects of pennyroyal supplementation on the internal quality traits of eggs stored under different times and temperatures. Therefore, according to the previous studies, oxidation of lipids in the egg's vitelline membranes, over time, increases the transfer of ions between the albumen and the yolk, which in turn increases the pH and ultimately reduces the Hough unit (Silversides et al., 2001). According to the findings of the present study, pennyroyal supplementation reduced production performance, egg quality traits, and internal quality traits of the stored eggs. Therefore, it is not recommended to use the pennyroyal powder supplementation in old laying hens’ diet to improve production performance and egg quality traits.

According to the United Nations, the world's population will increase by 2 billion in the next 30 years and reach 9.7 billion by 2050 (United Nations 2019), due to the imbalance between population growth and current agricultural production. It will face a serious challenge for development (Burke et al. 2005). Animal husbandry is one of the most important sub-sectors of agriculture and plays an important role in food security, which globally plays a significant share of GDP in many developing countries (Steinfeld and Mack 2015). In confirmation of this, according to FAO reports, about 50% of GDP in the agricultural sector and more than 20% of total GDP in most developing and even developed countries come from livestock (FAO 1993). In Iran, despite extensive efforts to establish new service organizations and changes in animal husbandry technologies, the productivity of livestock production in Iran is much lower than in developed countries (Rezvanfar et al. 2006). According to the above, it can be concluded that in our country, attention to animal husbandry development is inevitable due to its importance in providing food security and economy. But at present, the development of the animal husbandry in the country is facing many obstacles. Removing existing barriers and proper planning for the optimal allocation of resources in order to increase the productivity of this sector requires an understanding of the current situation and capabilities of this sector so that its development scenarios are based on existing realities. This requires recognizing the specific conditions of each region and planning in accordance with the developments and needs of the country with the correct use of new scientific and technical achievements, as a result of which different provinces of the country as intermediate levels are no exception. Therefore, considering the potential and real capacities of the livestock sector in Zanjan province, the present study aims to estimate the current situation of the animal husbandry and classify the cities of Zanjan province for principled and rational planning for the development of the animal husbandry in the province. The present study is a cross-sectional study in terms of the purpose of applied research and in terms of time horizons because it was conducted in a specific time period. It is also a descriptive-analytical research method that has been used to collect information from library and field studies. The study area cities of Zanjan province. The present study is based on the analysis of a set of indicators to identify levels of animal husbandry development in the cities of Zanjan province based on 45 indicators in four dimensions of population (10 indicators), technical-managerial (14 indicators), economic-financial (14 indicators) and Service infrastructure (index 7) is done. For data analysis, since the indicators are not of equal importance, the indicators were weighted using the AHP method. Then, according to the research approach based on the analysis of a set of indicators to identify the development pattern of each of the four dimensions in order to create a composite index, in this stage using 45 indicators for the four main dimensions of animal husbandry in Zanjan province with The TOPSIS multi-criteria decision making method was analyzed. Finally, after analyzing the data related to the main indicators and the total index, using the above results, using the techniques of Arc GIS, geographical information system, the cities of Zanjan province were zoned. The results showed cities of Zanjan province are different in terms of animal husbandry indicators and the cities have a different position according to the conditions that have animal husbandry indicators in different dimensions. Khorramdareh city in population composition index and technical-managerial index, Khorramdareh, Zanjan and Abhar cities in economic-financial index, Khorramdareh, Abhar and Zanjan cities in infrastructure-service index. Finally, in the total index, the cities of Khorramdareh, Abhar and Zanjan have been developed. Also, the situation of Zanjan cities in four dimensions of infrastructure-services, population composition, economic-financial and technical-managerial shows that in all cities of the province, economic-financial, technical-managerial and infrastructure-services indicators are not distributed in accordance with the population index, and the economic-financial index is distributed almost equally in all cities of the province, regardless of the needs of the city. The technical-managerial and infrastructure-service index in the center of the province and the cities of Abhar and Khorramdareh is higher than other cities in the province due to the existence of animal husbandry industrial centers. Based on the combined animal husbandry index in Zanjan province, it is clear that only Khorramdareh city is in a favorable situation compared to other cities and Abhar and Zanjan cities are in the middle level and the rest of the cities are underdeveloped, which shows the distribution of resources and infrastructure according to The capacity and needs of the animal husbandry sector in the cities of the province are disproportionate. Based on what can be concluded from the results of this study, the point is that in Zanjan province, the most important obstacle and problem in the development of the animal husbandry is infrastructure-service and technical-management issues. Planners and policymakers must first focus their plans on creating infrastructure appropriate to the different areas of the province's cities. In addition to providing infrastructure, providing services to the animal husbandry is essential to improve the quantity and quality of livestock and its products. Finally, what doubles the impact of infrastructure and services is technical and managerial issues, because if the infrastructure and services are optimal but the technical and managerial issues are not correct, development will not happen as planned by planners, Which is improved by hiring and consulting experts.

Changes in the pattern of animal protein consumption and a greater tendency to consume chicken in the last decade has greatly increased the demand for this product. Considering that 70% of the cost of poultry production is related to nutrition, so, it can be concluded that optimal nutrition is the most important way to reduce production costs in this industry (Abdollahi et al. 2013). Advances in broiler nutrition and breeding have increased growth rate and reduced breeding period over the past few decades. At present, broilers reach slaughter weight at the age of 42 days. Unfortunately, this high growth rate leads to problems such as metabolic disorders (sudden death Syndrome, skeletal disorders and ascites), increased mortality, and abdominal, and carcass fat (Khajali et al. 2007). Slowing down the growth rate by using dietary restrictions will greatly prevent these problems. At the same time, low growth is not economical and it is necessary to compensate for the backward growth of chickens due to food restrictions. Researchers have stated that the main goal of research on dietary restriction in broilers is to improve feed efficiency and reduce carcass and abdominal fat (Zhan et al. 2007). Depriving birds, especially broilers, of rapid growth from full access to the nutrients needed for normal growth is called feed restriction, which is classified into two categories: quantitative and qualitative. The response to feed restriction depends on the duration of the feed restriction (Khetani et al. 2009). In quantitative or physical feed restrictions, the consumption of birds or animals is limited. The practical application of physical feed restriction is not easy due to the problems of regular weighing of poultry and calculating daily feed intake (Zulkifli et al. 2000). Quality restriction is another method of applying feed restriction that aims to use diets with low energy and protein levels (Fanooci and Torki 2010). Urdaneta-Rincon and Lesson (2002) y applying 85, 90 and 95% quantitative feed restriction in male broilers at 5 to 42 days of age, they showed that the application of dietary restriction led to a significant difference in weight at 42 days of age and also a significant reduction in mortality. Bautzen et al (2003) in an experiment on broiler sex mixture and the application of quantitative feed restrictions at the ages of 6 to 16 days and 80% of the previous day's consumption of the control treatment, showed that performance was affected in the early weeks, but the restricted treatments at the age of 42 One day, they achieved the desired compensatory growth and no difference with the control group. Therefore, according to the reports on the use of feed restriction in reducing metabolic diseases and losses, it seems necessary to study feed restriction in broilers. In order to evaluate the effects of quantitative feed restriction, 300 one-day-old Ross broilers were each in a completely randomized design with five treatments, five replications and 12 pieces per replication for 42 days. The birds were fed ad-libitum up to 10 days then they were restricted from 11 to 35 days and they were fed ad-libitum up from 36 to 42 of age. Experimental treatments include: (1) Corn- soybean meal – based diet as a control group (no feed restrictions), (2) feed access to 95% control group, (3) feed access to 90% control group, (4) feed access to 85% control group (5) feed access to 80% control group. Diets were prepared according to the maintenance guidelines of Ross 308 strain. At 42 days of age, one chick from each pen was randomly selected and slaughtered, and the carcass traits such as breast, thigh, gizzard, liver, abdominal fat and carcass yield were determined. On day 35 of the breeding period, one chick from each experimental unit was randomly selected and slaughtered. The cecum of the birds was isolated and examined for the microbial population of Lactobacillus, Coliform and E. coli in the laboratory. Blood samples were also collected and then, centrifuged at 3000 rpm for 10 minutes and transferred to the laboratory to determine blood parameters (Cholesterol, Triglyceride, HDL and LDL). On day 35 of the experiment, some samples were collected and transferred to the laboratory to determine the percentage of dry matter, moisture, ash and volatile solids. To sample the waste, two hours before sampling, it was placed on the bed of each plastic pen and the waste were collected from five points of each pen. Experimental data were statistically analyzed in a completely randomized design using GLM procedure by software (SAS 2004) and the means were compared by Duncan's multiple range test at 5% probability level. The results showed that feed restriction decreased feed intake and body weight gain comparted with the control group (P<0.05). Carcass characteristics, FCR and feces characteristics were not affected by Feed restriction (P>0.05). Also, feed restriction at the levels of 85% and 80% significantly decreased protein excretion in comparison with the control group (P<0.05). Feed restriction at the level of 80%, increased cecal populations of Lactobacillus spp. While decreased cecal populations of E. coli (P<0.05). Feed restriction decreased blood triglyceride and increased blood LDL (P<0.05). Quantitative feed restriction clearly affected body weight gain and feed intake of birds. The degree of change in these parameters depended on the level of feed restriction used. There was a reduction in body weight gain at 42 d for chicks restricted to 95, 90, and 85%, of ad libitum feed intake, relative to the previous day’s intake of the control birds. Such a reduction in body weight is in accordance with results from Khantaprab et al. (1997), Roth et al. (1993), and Santoso et al. (1993a). Results suggest that the growth rate of broiler chickens is related to feed intake, which supports the statement that improvement in body weight of birds is highly correlated to feed consumption (O’Sullivan et al, 1992). Overall the results showed that although feed restriction up to 80%, decreased feed intake and body weight gain of broiler chickens at the total period of experiment, but this restriction improved microbial population of cecum, decreased blood LDL and protein excretion.

Energy and protein sources are of prime importance for ruminants as they stimulate microorganisms in the rumen and enhance the productive functions of the animals. Many species of rumen microorganisms can use ammonia as a nitrogen source for their growth and formation of microbial biomass that is key to meet the amino acid needs of the host animal. Because low-quality forages (<7% CP) are often limiting in protein, a positive relationship exists between ruminally degradable protein (RDP) supplementation and forage utilization (Koster et al., 1996). In contrast, it has been shown that forage intake did not affect mature ewes fed low-quality grass hay in response to increasing levels of supplemental RUP (Swanson et al., 2000). Similarly, Salisbury et al. (2004) reported no difference in roughage intake in wethers consuming low-quality hay supplemented with high or low RUP. However, those researchers suggested that RDP from forage could have been adequate to support ruminal fermentation. Urea is the main NPN source used in ruminants diets. However, there are still concerns regarding its use due to the rapid release of ammonia (NH3–N), which can be faster than its use by microorganisms for protein synthesis. The efficiency of protein synthesis from urea depends, among other factors, on energy availability in the rumen (Russell et al., 1992). Despite evidence of positive effects of RUP supplementation of fiber digestion, little information has been published observing the influence of slow-release urea (SRU) supplementation on the nutrient digestibility and DMI of ewe’s fed by low-quality forage. Also, feed sorting behavior that could be related to fiber digestibility in the rumen, has not been investigated in ruminant animals fed by increasing levels of slow-release coated urea. Therefore, the objective of this study was to determine how urea supplementation affects feed intake, nutrient digestibility, ruminal NH3–N, blood urea nitrogen concentration and feed sorting behavior in ewes.

A total of 28 Arabian ewes (40±2 kg live weight) were used in a completely randomized design with four treatments for 60 days. Experimental diets included 1- control (no urea), 2-1.2% conventional urea, 3- mixture of conventional and coated urea (Optigen®) (50:50 mixture; 0.6% and 0.675% ration DM respectively), and 4- coated urea (1.35% ration DM). Ewes were housed individually in pens (1.3 m×1.5 m) in an open shed building and were allowed ad libitum access to feed and water throughout the trial. All diets contained 60% forage (wheat straw) and 40% concentrate (60 : 40; forage : concentrate). The ingredients and chemical composition of the rations fed to ewes are shown in Table 1. The ewes were fed the total mixed rations ad libitum twice daily at 0800 h and 1700 h and had free access to fresh water at all times. Feed offered and refusal of each lamb were recorded daily. Digestibility was measured by the total collection of feces during a 5-d period. Samples of ruminal fluid were collected from each ewe 0 (before morning feeding), 3, 6 and 9 h post-feeding using a stomach tube attached to an Erlenmeyer flask and vacuum pump. The first 50 ml of collected rumen fluid was discarded to avoid saliva contamination. The remaining was filtered through four layers of cheesecloth. Rumen fluid pH was measured using a portable pH meter. Blood samples were taken from each lamb at the same time as ruminal fluid sampling by venipuncture of the jugular vein in 10-mL tubes treated with sodium heparin. Samples were centrifuged in a refrigerated centrifuge at 850 × g for 30 min within 30 min of sampling, and the plasma was frozen at −20 °C until used. The sorting index was calculated as the ratio of actual intake to the expected intake of particles retained on each sieve of the PSPS (Leonardi and Armentano 2003). The predicted intake of an individual fraction was calculated as the product of the DMI of the total diet multiplied by the DM percentage of that fraction in the fed TMR. A sorting index of 100, >100 and <100 indicated no sorting, sorting for, and sorting against respectively. Data were analyzed using a GLM procedure of SAS 9.2 (SAS Institute, Inc., Cary, NC). Comparisons between treatments were completed with Tukey’s test. Treatment effects were declared significant at P≤0.05.

The results showed that the experimental treatments had no significant effect on intake of dry matter, organic matter, neutral detergent fiber and acid detergent fiber. Crude protein intake was lower in the control treatment relative to the other treatments (P <0.05). This finding was expected urea-containing diets designed to have higher CP content. Apparent digestibility of dry matter, crude protein, neutral detergent fiber and acid detergent fiber was not affected by the treatments. Apparent digestibility of organic matter increased in animals who received coated urea relative to the control treatment (P < 0.05). The ruminal pH of ewes was not affected by dietary treatments before morning feeding and 9 hours post-feeding. An increase in rumen pH was observed in coated urea treatment relative to the control group, 3 and 6 hours post-feeding (P < 0.05). Animals fed coated urea also had higher rumen pH compared to those fed common urea and a mixture of coated urea and common urea (P < 0.05). Rumen ammonia nitrogen concentrations were higher in all urea-containing treatments compared to the control treatment, 3 hours post-feeding (P = 0.002). At 9 hours post feeding, coated urea treatment had higher ammonia nitrogen concentration than common urea and mixture of coated urea and common urea treatments and lowest concentration observed in the control treatment (P = 0.009). Blood urea nitrogen was also higher in 3 and 6 hours post feeding in all urea-containing treatments than the control treatment (P <0.05). Ewes fed a mixture of conventional and coated urea sorted in favor of medium particles relative to other treatments (P = 0.03). Regardless of treatments ewes sorted against the longest ration particles (>19 mm) and sorted for fine particles (<4 mm) dietary particles.

Results of this study showed that increasing levels of coated urea in diets containing low-quality forage have the potential to keep higher rumen ammonia nitrogen concentration for a longer period but this increase didn’t have a positive effect on nutrients digestibility compared to conventional urea.

Forage sorghum is a valuable plant that tolerates environmental stresses such as drought and heat, which can be used for direct grazing, green forage, dry forage and silage. One of the most important advantages of sorghum is having diverse genotypes that allow the use of appropriate cultivars based on the type of consumption at the time required by the farmer for Their farm animals. Forage quality is highly correlated with fiber components such as NDF (neutral detergent insoluble fiber), ADF (acid detergent insoluble fiber) and lignin (Gholami, 2014; Moore, 1994). To compare forage quality, agronomists and livestock nutritionists use common shortcut units such as RFV (relative value of forage) and RFQ (relative quality of forage), which are highly correlated with the amount of milk and meat produced by livestock. Relative Forage Value (RFV) is a quality comparison index based on digestible dry matter content (DDM) and livestock forage consumption (DMI), which is obtained indirectly from NDF and ADF. Relative forage quality (RFQ) is also a quality comparison index based on total digestible nutrients (TDN) and DMI, which is more accurate than the RFV index due to NDF digestibility (Moore and Andersander, 2000). Due to the production potential and high growth rate in forage sorghum genotypes and also the high resistance of this plant to environmental stresses, this plant seems to have a good ability to produce forage in semi-arid regions. However, there is little information about forage quality in domestic and foreign cultivars and hybrids of forage sorghum in the country and most of the available information emphasizes the quantitative performance of sorghum cultivars; Therefore, the present study was conducted to investigate the potential of forage production in domestic and foreign genotypes of forage sorghum and considering both forage quantity and quality indices to the most suitable domestic and foreign cultivars of forage sorghum for high forage production and nutritional value Be properly identified. Eighteen cultivars, lines and hybrids of forage sorghum were evaluated, planted and harvested at Karaj Seed and Plant Breeding Research Institute. In order to determine the dry matter yield and also to evaluate the quality traits, five plants from each plot were randomly selected and weighed in an oven at 60 ° C until reaching a constant dry weight. Finally, dry matter yield was calculated in the samples. To determine the quality traits, the dried samples were ground. Qualitative traits of forage including crude protein content, ADF, NDF and lignin were determined by the Iranian Institute of Animal Sciences Research by chemical analysis (AOAC, 2002). The digestibility of the samples was determined by the gas test method and the amount of metabolizable energy in the forage was estimated using the amount of gas produced in the twenty-fourth hour and the amount of crude protein (Menke and Steingass, 1988). The means were compared by LSD method at the level of 5% probability. The results showed that the studied genotypes in terms of plant height, number of tillers and number of leaves per plant were significantly different at the level of one percent probability, while the effect of genotype on stem diameter was not significant. Among the internal genotypes, maximum fresh forage yield (103.84 tons per hectare) was obtained by Pegah cultivar and minimum yield (63.16 tons fresh forage per hectare) was obtained by KFS2 line. The highest dry matter yield (20.61 t / ha) was obtained by Siloking cultivar and the lowest (8.83 t / ha) was obtained by Juicy Sweet BMR SSH.2 cultivar. There was a narrow difference in forage crud protein content, so that the average of crude protein in all studied genotypes was 6.357, internal genotypes was 6.363 and external genotypes 6.354%. The mean NDF in all studied genotypes was 60.36%, internal genotypes 62.06% and external genotypes were 59.51%. Among the studied genotypes, the highest amount of NDF (69.75%) was obtained in Titan cultivar and the lowest NDF content (54.25%) in PHFS-27 cultivar. The average lignin content in all studied genotypes was 1.78, internal genotypes was 1.71 and external genotypes 1.82%. The average metabolizable energy in all studied genotypes was 2.41, internal genotypes 2.33 and external genotypes 2.44 Mcal per kg of dry matter. Juicy Sweet BMR SSH.2 and PFS-21 cultivars had the highest ME levels with 2.67 and 2.64 Mcal of metabolizable energy per kilogram of dry matter, respectively, while Speedfed and Titan cultivars had the highest metabolizable energy ( Produced 2.13 and 2.17 Mcal per kilogram, respectively. The average relative value of forage (RFV) in all studied genotypes was 99.74, domestic genotypes 96.96 and foreign genotypes was 101.13%. The maximum RFV index among external genotypes was obtained by PHFS-27 cultivar (115.75%) and among domestic genotypes by Pegah cultivar (111.38%); While the minimum relative value of forage was observed among foreign genotypes by Titan cultivar (76.28%) and among domestic genotypes by Speedfed cultivar (79.73%). Siloking cultivar, which while producing the most dry matter per unit of area had a high rate of relative forage quality index, is introduced as the most suitable cultivar in terms of quantity and quality of forage. Among domestic genotypes, Speedfed hybrid was able to produce the highest dry matter yield, but was not of good quality. Therefore, planting SpeedFeed cultivar to produce forage will be recommended in situations where only the quantity of forage is important for the farmer. Pegah cultivar, which had good dry matter yield and good forage quality, is introduced as the best domestic genotype for forage production.