جستجوی مقالات مرتبط با کلیدواژه « carcass characteristics » در نشریات گروه « علوم دام »

This study aimed to compare the relative weight of visceral organs, different carcass cuts, the relative length of different intestinal segments, meat quality, hematocrit, and blood metabolites between Arian and Ross308 broiler strains. 

One-day-old mixed-sex broiler chickens from Ross308 and Arian strains were separately allocated to two treatment groups. The initial number of each broiler strain was 48, divided into 12 replicate cages with four chicks each. On days 32 and 42, one bird per replicate was randomly selected (12 broilers from each treatment group), weighed, and killed by cutting the jugular vein with a sharp knife. Then the relative weights of visceral organs and relative length of small intestine segments were determined for both strains. The carcass characteristics and the breast and thigh meat quality (including water-holding capacity, cooking loss, and lipid peroxidation) were assessed only in the birds killed on the 42nd day of age. Some plasma metabolites and hematocrit were also determined after blood collection into heparinized tubes at the end of the rearing period.

The results showed that the total feed intake of Arian broilers was higher than that of Ross 308 (P≤0.05), but no difference was observed in the feed conversion ratio (FCR) between the two strains. The rate of weight gain in the first two weeks was higher in the Arian strain (P≤0.05). However, this trend was reversed during the 5th week of the rearing period. The carcass and valuable cut yields at 42 days of age were higher in Ross308 broilers compared to Arian birds (P≤0.05). On both days of slaughter, the gizzard relative weight was higher in Arian broilers, while the bursa relative weight was lower in this strain compared to Ross308 (P≤0.05). The visceral fat relative weight showed a significant difference between the two strains only at 42 days of age, and it was higher in the Arian broilers (P≤0.05). There was no strain difference in relative weight of the gut and different segments of small intestine at both examined ages. However, the proportion of the jejunum to the total length of the small intestine in the Arian strain was significantly higher than that of the Ross 308 (P≤0.05). Mean plasma uric acid concentrations were significantly lower in Arian compared to Ross 308 (P≤0.05). However, the mean concentration of plasma total triglycerides and hematocrit values were higher in Arian broilers (P≤0.05). The amount of stimulated malondialdehyde in the breast and thigh meat showed higher values in the Arian broilers (P≤0.05), indicating the lower oxidation stability of the chicken meat of the Arian broilers compared to Ross308.

According to the results of the present study, Arian was not competitive with Ross 308 as a well-known commercial broiler strain in terms of the examined parameters. However, by gaining a better understanding of the weekly performance, carcass characteristics, and blood parameters of the Arian strain at different ages and in comparison with the Ross 308, the broiler farmers will be able to adopt the best management and nutritional strategy for raising these native broilers chickens.

Early post-hatch feed and water deprivation, as happens practically, may negatively influence the growth performance and health of broiler chickens due to severe dehydration, suppressed mitotic activity of satellite cells, poorer gut health, and development as well as retarded yolk sac (YS) absorption. Decelerated YS absorption may be associated with a higher incidence of YS infection and lower transfer of maternal antibodies from the YS to the chick body. Royal Chick is a nutritious gel providing adequate quantities of water and essential nutrients for newly-hatched chicks. The product also contains probiotic organisms, prebiotic, yeast nucleotides, and natural anti-stress substances. Royal Chick is an innovative nutrient-enriched powder product that forms a jelly mass when mixed with water. As claimed by the manufacturer, the product prevents initial weight loss, alleviates oxidative stress, improves skeletal muscle growth, and stimulates the development of the digestive and immune systems of the newly hatched chicks. This study aimed to evaluate the effect of early feeding with Royal Chick on productive performance, carcass traits, immune system function, and jejunum morphometry of broiler chickens. A total of 420 d-old straight-run Ross 308 broiler chicks were used in a completely randomized design with 5 treatment groups and 6 replicates per each. A group of chicks were deprived of both feed and water for the first 24 h post-hatch and served as control (CON). In the second group, each bird was treated with HRCH gel in two separate 2 g dosages from which the first was given in the chick box and the second was administered immediately after placement in combination with the first meal of the starter diet (T1). In the third group, each bird was treated with a mixture of 2 g HRCH and 2 g starter feed in the chick box (T2). In the fourth group, each bird was treated with a single 2 g dose of HRCH in the chick box (T3). In the fifth group, each bird received a mixture of 2 g HRCH gel and 2 g starter feed immediately after placement (T4). All chicks were held in chick box up to 24 h post-hatch and then were transferred to the associated floor pens and reared for 42 days on standard starter (2 to 10 d of age), grower (11 to 24 d of age), and finisher (25 to 35 d of age) diets. On days 10, 24, and 35 birds of each pen were weighed together. Offered feed and refused feed were also weighed and mortality records were kept for each phase. Then weight gain (WG), feed intake (FI), and mortality-corrected feed conversion ratio (FCR) were calculated. On days 2 and 25, blood samples were taken from 2 birds per replicate to evaluate maternal immunity and humoral immune responses to vaccination against Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and avian influenza virus (AI). The birds from which blood samples were taken on day 2 were killed at the same time to measure residual yolk sac weight. At the end of the experiment, 2 female birds per pen were weighed and decapitated to investigate carcass traits and to sample the mid jejunum for morphometric analysis. Birds in T1 and T2 groups tended to have lighter residual yolk sac than their control counterparts (P=0.076). During the starter phase, T2, T3, and T4 groups had significantly (P<0.05) higher WG and FI compared to those in the control group with no improvement in FCR. During the grower phase, the T4 group consumed more feed than the control one (P<0.05). No treatment effect was detected on performance traits at the finisher phase and throughout the experimental period (P>0.05). Birds in T2 and T3 groups produced the most pronounced antibody responses against IBV. The highest carcass yield was obtained in birds treated with a combination of HRCH and starter feed in the chick box (T2). The same birds also tended to have the highest breast yield (P=0.077). Administration of hydrated Royal Chick gel in chick box (with or without a starter diet) or immediately after placement (in combination with a starter diet) can bring beneficial effects on the health and productivity of broiler chickens. Further investigations are necessary to identify possible interactions of different EF regimens involving HNG with breeder age, deprivation duration, and pre-placement environmental conditions on subsequent performance and health status in broiler chickens.

High concentrated diets are rapidly degraded in the rumen and lower ruminal pH by rapid and high lactic acid production. The use of chemical or biological buffers improves digestion and fermentation conditions in a high concentrate diet. The aim of this study was to compare the effect of using acid-consuming bacteria as pH regulator (biological buffer) and chemical buffer to improve digestibility and fermentation of high concentrate diets.

In the present experiment, 21 fattening Arabi male lambs with an average weight of 34.35±2.50 kg and an average age of 8±1 months old were used in a completely randomized design with 3 treatments and 7 replications for 50 days. Experimental treatments were included: 1- control diet (70% concentrate and 30% forage, without buffer and bacteria), 2- control diet + 1% sodium bicarbonate buffer, 3- control diet + 3 ml of Megasphaera elsdenii bacteria with 2 gram yeasts of Saccharomyces cerevisiae (bacterial-yeast).

Nutrient digestibility and growth performance parameters were not affected by experimental treatments. Rumen protozoa population was significantly higher in bacterial-yeast treatment than control (p<0.05). Ammonia nitrogen concentration and ruminal pH were affected by experimental treatments, and compared to control treatment, in treatments containing chemical or biological buffer, ruminal pH increased and ammonia nitrogen decreased. But blood and liver parameters, carcass characteristics such as size and weight of carcass parts, meat colorimetric characteristics were not affected by experimental treatments (p<0.05).

Overall, the results of the present experiment showed that the use of acid-consuming bacteria as pH regulators has competitive effects with bicarbonate buffer and even better in some cases.

As respects Food processing may increase livestock performance. Today some methods of grain processing have been considered. On the other hand, lack of animal feed, especially with the development of industrial methods of animal husbandry waste in many parts of the world, has led farmers and researchers to think about identifying and using agricultural and livestock waste and new food sources for animal nutrition, including poultry manure. And urea is mentioned in the diet of ruminants. Due to the fact that no research has been done on the effect of barley grain processing methods and non-protein nitrogen sources in the diet on growth performance, nutrient digestibility and carcass characteristics in of Afshari breeding fattening lambs, the present study was conducted.

This experiment was conducted in a completely randomized design with seven treatments including a control treatment containing whole barley grain (without milling) and without urea and chicken manure, treatments 2, 3 and 4 respectively containing processing method of milling, filling and pelleting with a certain level of urea. (1%) And treatments 5, 6 and 7 containing processing methods of milling, filling and pelleting with a certain level of poultry manure (12%) were performed on Afshari breeding fattening lambs. Each treatment consisted of 5 fattening lambs at the age of 3 months 24±1 which were kept individually in separate cages for 14 days of acclimatization period and 84 days of fattening period. Dry matter, ash, crude fiber, crude fat and crude protein were determined using the method (AOAC, 2000), Neutral detergent fiber and Acid detergent fiber based on the method of Van Soest et al (1991). At the end of the rearing period, three heads from each treatment were randomly sacrificed and hot carcass weight and cold carcass weight and its components were measured.

The number of daily feed intakes, daily weight gain and feed conversion ratio were significantly different between experimental treatments. The apparent digestibility of dry matter and organic matter were significantly different, and the control treatment (whole barley grain without urea and poultry manure) had the highest apparent digestibility. Digestibility in non-fibrous carbohydrates was significantly different, so that treatment 5 (processing method of milling with poultry manure) had the highest apparent digestibility. Experimental treatments were significant on thigh weight, neck weight, tail weight, ventricular fat weight, carcass length and half-carcass length.

The results showed that barley grain processing methods with non-protein nitrogen sources had a significant effect on daily weight gain, dry matter consumption, feed conversion ratio, some organs of fattening lambs, digestibility of dry matter, and organic matter compared to the control group. In general, it is possible to use barley grain processing with urea (1%) and poultry manure (12%) in the diet of fattening lambs without harmful effects on production parameters and fattening performance.

The aim of the present study was to evaluate the effect of fodder beet on performance, carcass traits and blood parameters of fattening male lambs. 32 fattening male lambs with an initial weight of 28.05 ± 0.25 kg by using a completely randomized block design with four treatments and four blocks for 84 days were fed with experimental diets including control (zero), 10, 20 and 30% fodder beet with the ratio 60% of the concentrate and 40% of the fodder as total mixed ration twice a day. During the experiment period, there was no significant difference in the weight of the lambs among the control group and the groups in which different levels of fodder beet were used in their diets. There was no significant difference in average daily gain among all groups except for the lambs fed with 20% fodder beet diet. In the group that received 30% fodder beet, the feed intake (DM/d) was the lowest compared to other groups (P<0.05). No significant difference in the feed conversion ratio among the experimental groups was observed. There was no difference in slaughter weight, empty-body weight, hot and cold carcass weight, carcass traits and carcass dressing percentage of lambs among different groups (P>0.05). The experimental treatments had no effect on the biochemical characteristics of lambs blood, but fodder beet intake increased blood hemoglobin (P<0.05). Based on the results, fodder beet up to 30% could be used in fattening lamb diets without negative effect on performance, carcass characteristics and blood parameters.

Fattening operations play an important role in the supply of animal protein, which in addition to producing more meat, the quality of meat also improves, because proper nutrition and the use of proper fattening methods accelerate the growth and improve the quality of meat. In order to achieve optimal and economical production in sheep breeding, a nutritional program must take into account the nutritional needs of livestock, the quality of food and their consumption time. However, due to the reduction of forage and pastures in Iran, the farmer is forced to use more concentrate in the diet. The aim of this study was to investigate the effects of fiber reduction and alfalfa removal on feed intake, body weight, feed conversion ratio and carcass characteristics of Afshari male lambs.

The present study was performed using 36 Afshar male lambs with a mean live weight of 32.53 ± 1.9 kg and a mean age of 93 ± 6.63 days for 90 days based on a factorial experiment based on a completely randomized 2×2 design. Experimental treatments include treatment of frist: fattening diet containing 80% concentrate and 20% forage (10% wheat straw and 10% alfalfa), second treatment: fattening diet containing 80% concentrate and 20% forage (20% wheat straw and 0% alfalfa), third treatment: fattening diet contained 90% concentrate and 10% forage (5% wheat straw and 5% alfalfa) and fourth treatment: fattening diet contained 90% concentrate and 10% forage (10% wheat straw and 0% alfalfa). The lambs were fed three times a day at 8.00, 14.00 and 20.00 for ad libitum. At the end of the feeding period, all lambs were weighed after 16 h feed deprivation and four lamb from each treatment was slaughtered. The data were analyzed using Spss21 and Excel.

There was a significant difference between different treatments in terms of weight gain. Treatment four with 90% concentrate and 0% alfalfa had the highest (300 g) and treatment one with 80% concentrate and 10% alfalfa produced the lowest daily weight gain (200 g) in lambs. With increasing concentrate and removal of alfalfa, feed consumption increased so that the highest amount was related to treatment four (1.830 g) and the lowest was related to treatment one (1.476 g). Treatment four had a numerically lower conversion ratio (6.1) compared to the other three treatments. The mean final weight of lambs, hot and cold carcass weights showed significant differences between experimental treatments.

According to the results, the removal of alfalfa did not cause any production problems in these areas. Increasing the concentrate and eliminating alfalfa in the diet increases feed intake and daily weight gain and overall higher final weight in fattening periods and also improves feed conversion ratio, growth performance and carcass percentage.

This study was conducted to evaluate the effects of adding different levels of a domestically produced synbiotic to drinking water on production traits, carcass characteristics and the small intestinal microbial population of broiler chickens. Four hundred one-day-old Ross 308 broilers (a mixture of two sexes with equal proportion) were used in a completely randomized design with 4 treatments, 5 replicates, and of 20 birds per each replicate. Experimental treatments included adding levels: zero (control), 50, 100 and 150 g of synbiotic (Biopoul) per 1000 liters of drinking water. At 42 days of age, the addition of 50 or 100 g of synbiotic per 1000 liters of drinking water significantly decreased feed conversion ratio (P < 0.05). The increase of production index in the group receiving 100 g of Biopoul compared to the control showed a tendency (P = 0.08). Biopoul in the levels of 50, 100 and 150 g increased the total number of lactobacilli and decreased the number of yeasts and molds, coliforms and total gram-negative bacteria in the ileum compared to the control (P<0.05). According to the obtained results, the use of 100 g of synbiotic Biopoul per 1000 liters of drinking water of broiler chickens can improve the production index while helping to balance the small intestinal microbial population.

The ideal performance of poultry is achieved by adequately feeding of birds while reducing dietary costs and nutrients excretion. On the other hand, the amount of dietary nutrients can have a significant effect on feed intake (Kidd et al., 2002). Studies have shown that reduced growth and yield due to decreased dietary protein can be compensated by supplementing the synthetic amino acids (Hussein et al., 2001). Diets based on total and digestible amino acids can improve the performance (Rostagno et al, 1995). Some properties of valine and tryptophan in relation to non-protein function and metabolism distinguish them from other amino acids. Valine is the fourth limited amino acid to the growth of broilers. Tryptophan involved in all proteins structure and is a precursor for serotonin and melatonin, which in addition to improving food intake (Silber and Schmitt, 2010). Valine affects the ghrelin and neuropeptide Y production (Coto et al, 2006) while tryptophan affects the serotonin secretion (Henry, 1985) that both affects the feed intake. The functions of the two amino acids can improve the performance and immune system of birds.

The current experiment was performed to evaluate the effects of different levels of valine and tryptophan amino acids in low-protein diets on carcass characteristics and immune response of broiler chickens. A total of 450 day-old Ross 308 broiler chickens were randomly divided into nine treatment groups. The chickens were arranged in a 3×3 factorial experiment based a completely randomized design including 3 levels of valine and three levels tryptophan. Each treatment considered of five replicates and 10 chickens per experimental unit. The birds were reared on the litter pen for 21 days with ad-libitum access to feed and water. Diets were formulated based on linear programming by using of the UFFDA software. Experimental treatments were adjusted based on Brazilian tables and included: 1- recommended level of valine + recommended level of tryptophan, 2- recommended level of valine + 5% more than recommended tryptophan, 3-recommended valine level + 10% more than recommended tryptophan, 4-10% more than recommended valine level + recommended level of tryptophan, 5-10% more than recommended valine + 5% more than recommended tryptophan, 6- 10% more than recommended tryptophan level + 10% more than recommended tryptophan, 7- 20% more than recommended valine level + recommended level of tryptophan, 8- 20% more than recommended valine + 5% more than recommended tryptophan, 9-20% more than recommended valine level+ 10% more than recommended tryptophan. On day 21 of experiment, two birds per pen were randomly selected and slaughtered for whole carcass analysis after 12 hours of fasting. After slaughter, the organs such as breast, thigh, abdominal fat, gizzard, liver, heart, spleen, thymus and burs fabricius were weighed. In order to determination of white blood cells, blood sampling drawn from the wing vein at 21 days of age and the number of lymphocytes, heterophils, monocytes, basophils and eosinophils were determined. Blood samples were taken at 21 days of age as well to determination of the antibody titer of Newcastle virus. To measure the immune response to sheep erythrocytes, 2 ml of blood was taken from the chicken vein on 14 and 21 days of the experiment and used to determination of total immunoglobulin and IgM and IgG titers. The antibody titers were performed by direct hemagglutination (Isaco et al. 2005). The CBH test was used to evaluate the cellular immunity. The experiment was conducted using completely randomized design with factorial structure. Data were subjected to ANOVA using the GLM procedure (SAS, version 9.1) as a 3×3 factorial. Significant means among the variables were separated by Duncan's multiple range tests at 5% level of significance.

The results of current experiment showed that the addition of valine and tryptophan in low protein diets had no significant effect on carcass yield, thigh, gizzard, heart and abdominal fat (p<0.05). The consumption of 20% and 10% levels of valine significantly increased the breast weight as compared to the recommended level (p<0.05). No interaction effects was observed between the valine and tryptophan amino acids for the weights of carcass parts and internal organs (p>0.05). In a study, consumption of 10 and 20% tryptophan levels had no significant effect on breast and thigh of broilers at 22 days of age (Duarte et al, 2013). Moreover, addition of valine to poultry diets did not have a significant effect on abdominal fat weight (Corzo et al, 2004). Different levels of valine and tryptophan had no affected the liver and spleen weight (p<0.05). Furthermore, addition of 20% valine caused an increase in thymus and bursa weights (p<0.05). The diets containing tryptophan had a significant effect on the number of blood lymphocytes, so that the addition of 10% tryptophan increased the blood lymphocytes (p<0.05). Valine and tryptophan addition did not affected the other blood leukocytes (p<0.05). Addition of 20% valine increased the humoral immunity (HI antibody titer) (p<0.05). Also, addition of 10% tryptophan level increased the immunity of chickens against HI antibody (p<0.05). The results showed that the initial response of total antibody was not affected by experimental treatments (p<0.05) but 10% level of valine significantly increased the IgM (p<0.05). Dietary addition of 20% valine had a significant effect on IgM secondary response SRBC (p<0.05) but had no significant effect on the PHA-P injection response (p<0.05). It has been reported that protein deficiency have caused the unsuitable growth of lymphoid organs (Corzo et al., 2007).

The result of current experiment showed that consumption of high valine and tryptophan levels in low-protein diets improved the carcass characteristics and immune system of broilers.

Effect of Basil powder and extract on yield and carcass characteristics, relative expression of heat shock protein gene (HSP70) and someblood parameters of broiler chickens under heat stress using 160 Ross 308 one-day-old broiler chicks in a completely randomized designwith 5 treatments and 4 replications (8 chickens per replication), was evaluated for 42 days. Treatments included: 1- Basic diet (control), 2-Basic diet+ Vitamin C (250 mg per kg of grain), 3- Basic diet + 25 mg of Basil powder (per kg of grain), 4- Basic diet +50 mg of Basilpowder (per kg of grain), 5- The use of Basil extract (1 ml/liter water). Feed intake, body weight gain, feed conversion ratio, carcasscharacteristics, blood parameters and relative expression of HSP70 gene in blood were measured. The effects of treatments on bloodparameters and carcass characteristics were not significant. Relative expression of the HSP70 gene in the blood was significantly reduced inall treatments compared to the control (P<0.05). Based on the results, basil powder and extract reduce the negative effects of heat stress inbroilers, so their use in broiler diets is recommended to prevent heat stress.

Compensatory growth is actually a physiological process in which the animal's potential, after a period of dietary restriction, can be exploited to increase growth and growth efficiency during the free feeding period (Hornick et al 2000). Compensatory growth is widely used today in various countries. Another specific management approach (short-term strategies) in lamb fattening is appropriate weight at the beginning of fattening (Santos Silva et al 2002). The benefits of applying a compensatory growth mechanism during the breeding period can be improved feed efficiency during the compensatory growth period (Abouhif et al 2013 and Sami et al 2016), reduced feed cost throughout the breeding period, also improved weight gain during the breeding period (Clark et al 2007; Abuhif et a l 2015) and reduced energy maintenance needs (Kamalzadeh et al 2009; Shadnosh et al 2011). Considering the feedlot of 320,000 fattening lambs in Lorestan province per year and the possibility of using feed restriction to promote the use of compensatory growth in lamb fattening, the project was carried out aims to investigate the possibility of process changing the growth rate, fattening and physical and chemical composition of carcass lambs Lori breed by short-term strategies of feed restriction.This study was conducted to investigate the effect of different weight start of feed restriction on growth performance and carcass lambs traits Lori breed lambs.

Fifty four male Lori lambs with a mean live weight of 26 kg were selected for the experiment. Treatments were consisted of 6 feed restriction treatments (60,80%) and ad libitum(fattening diet without restriction) for two weights (30 and 35 kg). At the beginning of expriment, 54 experimental lambs were fed the same diet.After a 14 day pre-feed restriction period, a group of 27 individuals that had reached an average weight of 30 kg were separated from the rest and subjected to feed restraint treatments. The remaining 27 lambs were fed the former diet for 35 days until reaching a weight of 35 kg. Upon reaching this group, an average of 35 kg dietary restriction was applied.The feed restriction period for both groups was 30 and 35 kg for 35 days. Then the 30 kg group for 49 days and the 35 kg group for 28 days until the end of the fattening period were re-fed the control diet (fattening ration without restriction and ad libitum). At the end of experiment, daily weight gain, final weight, feed conversion ratio, feed efficiency and feed intake were calculated and then three lambs were slathered from each treatment. Carcass characteristics were calculated with the cost of production per kg of weight gain, carcass and lean meat. Analysis were done by repeated measurements basis on a completely randomized design with a mixed model procedure. Comparison of mean treatments was performed by Tukey test. The statistical model was as follows:Yijk= μ + Ti+ Dk + Aij+ (T*D)ik + εijk.

The results of Table 2 showed that the effect of the experimental diets had no significant effect on all the traits of lambs weighing 30 and 35 kg over the pre-feed restriction period. Results showed that there were significant difference between the final weight of lambs at the end of feed restriction period (P<0.05). At the end of the re-feeding, no significant differences were observed among the control treatment (30 and 35kg) with 60 and 80% feed restriction groups. In the present study, at the beginning of the re-feeding period in the respective treatments, the daily weight gain in the feed restriction treatments was significantly higher than the control groups at 30 and 35 kg. There were significant difference among intake dry matter of lambs at the end of feed restriction period (P<0.05). At the end of compensatory growth, there was observed no significant difference between control and restriction groups. During the re-feeding period, feed conversion ratio was lower in feed restriction treatments compared to control treatment (30 and 35 kg). Compensated feeding reduced FCR in lambs with prior feed restriction compared to control. The results showed that feed efficiency and feed intake needed to maintain live weight are affected by the animal feeding program. Results of physical composition of carcass during re-feeding showed that the average of most carcass traits in the control treatment (30 and 35kg) and 80% of feed restriction treatment for 30kg lambs had no significant difference and were higher than other groups. Also in the compensatory growth experiment, there was no significant difference between the number of empty body weight, hot carcass and cold carcass weight sa well as dressing percentage due to no difference in the final live weight between the 30 and 35 kg control groups with 80% feed intake. Another study in other ruminants was consistent with feed restriction and compensatory growth.Meanwhile, the fat tail weight and percentage and total carcass fat were higher in the control treatment (30 and 35kg) than in all control groups. The results showed that the percentage of carcass lean meat in the compensatory groups was higher than the control treatments. This study showed that lambs with 80% feed restriction for 30kg lambs due to higher weight gain and FCR were more favorable in terms of fattening condition than control lambs who consumed feed during whole period. Also, this treatment was the total carcass fat percentage lower and lean meat higher and ultimately, the production costs per kg carcass and lean meat were lower than other treatments.

This experiment was conducted to evaluate effect of feed form and stocking density on performance and some behavioral parameters of 208 one-day-old broiler chickens (Ross 308), for 42 days.  Treatments were 2 feed forms (pellet versus mash) and 2 levels of density (10 and 16 birds/m2) that was performed in completely randomized design with 2×2 factorial arrangement and 4 replicates. Performance parameters were recorded weekly and carcass characteristics measured on day 42 of age. For evaluating behavioral parameters, 8 cameras were used. The results showed that feed intake, body weight gain and feed conversion ratio were improved in broilers fed pellet diets compared to the birds fed mash diets at whole period of experiment (P<0.05). Abdominal fat was increased in birds that consumed mash diet in high stocking density (P<0.05). In the morning of the third week, the activity index of birds that consumed mash diet in high stocking density increased significantly (P<0.05). The results of this study indicate that feed form could not affect performance and behavioral parameters of broilers in high stocking density, although, pelleting diets improved performance parameters and high stock density increased average around feeder activity of broiler chickens.

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

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

The current experiment was conducted in order to compare the effects of Yaghooti Grape (V. venifera) along with commercial antioxidant of Butylated hydroxytoluene (BHT) on performance, biochemical parameters and carcass characteristics of broilers. 150 day-old Ross 308 male chicks were randomly distributed in to 5 experimental treatments with 3 replicates and 10 chicks per replicate in completely randomized design manner for 42 days. Experimental groups were: Control (basal diet with no additive); Basal diet with 150 ppm Yaghooti grape Methanolic extraction; basal diet with 3% Yaghooti grape pulp; basal diet with 3% Yaghooti grape juice and basal diet with 200 ppm BHT. Results showed that different dietary treatments had no significant impact on performance including body weight, feed consumption and feed conversion ratio, liver enzymes and intestinal components in all studied treatments, compared to control group. Application of 3% of grape pulp in broiler diet led to significant reduction in cholesterol, triglyceride, LDL and increase in blood serum HDL. For carcass characteristics, grape pulp has significantly increased relative carcass and breast weights and reduction in gizzard and liver weights in broilers, compared with control group. Therefore, it can be concluded that treatment with Yaghooti grape pulp can be a suitable replacer for BHT commercial antioxidant in terms of biochemical parameters and carcass characteristic’s improvement in commercial broilers.

The present study aimed to characterize the effect of dietary Ca-salts of palm oil (PO) and fish oil (FO) on performance, carcass characteristics, and meat quality of growing lambs. The lambs (n=20; IBW=32.7±2.8 kg, 4-5 month-old) were randomly assigned to one of two treatments (10 lambs/treatment) based on IBW and kept individual pens. Lambs were offered one of two diets, 1) control (2.5% PO) and 2) 2.5% FO for 90 days. At the end of the experiment, lambs were slaughtered and carcass characteristics and meat quality were measured. All data were analyzed based on a completely randomized design using the general linear model procedure of SAS. Results showed that Ca-salts of PO and FO did not affect animal performance, carcass traits, and chemical composition of Longissimus dorsi muscle (LDM). Also, shear force, cooking loose, and drip loose percentage of LDM did not affect by treatments. Feeding FO increased odor score (6.13 vs. 5.06) and decreased overall acceptability of meat (4.21 vs. 5.41) compared to PO (P<0.05), while the other sensory characteristics of meat (tenderness, flavor, and juiciness) were not affected by treatments. In conclusion, the feeding of 2.5% Ca-salts of FO increased the fishy odor in the lamb meat according to the sensory panel without changing the performance and carcass characteristics.

An experiment was conducted to evaluate the effects of ASRI1, ASRI2, commercial growth promoter and prebiotic on performance, carcass characteristics and small intestinal morphology of broiler chickens. A total number of 875 day-old Ross 308 chickens were used in a completely randomized designed as a 2×3 factorial with six treatments, five replicates of 25 birds per each. Chickens were fed with three types of growth promoter (ASRI1, ASRI2 and commercial growth promoter) and two levels of prebiotic (0 and 1 kg/ton of diet). Body weight, feed intake and feed conversion ratio were not affected by herbal growth promoter and prebiotic (p>0.05). Effects of growth promoters and prebiotics on carcass characteristics were not significates, but prebiotic reduced the carcass yield (p < 0.05). Relative weights and lengths of intestinal tracts and morphological indices were not affected by growth promoter and prebiotic. Finally, based on the results of this research, commercial growth promoters could be substituted by ASRI1 and ASRI2.

The aim of this experiment was to compare the feedlot performance and carcass characteristics of Lori Bakhtiari and Romanov×Lori-Bakhtiari crossbreed lambs. Forty-four Lori-Bakhtiari lamb and Forty-four Romanov×Lori-Bakhtiari lambs were used in a completely randomized design and using a factorial method (2×2) during two consecutive years. The average daily gain and daily feed intake were determined by individual weaning of each animal and then feed conversion ratio was calculated. Carcass characteristics of lambs were measured. The results showed that average daily gain during fattening period (212.1vs. 179.6 g), final fattening weight (52.12 vs. 48.26 kg), feed intake, carcass weight and fat tail percentage in Lori Bakhtiari lambs were greater than Romanov× Lori Bakhtiari crossbred lambs. The average daily gain before weaning (298.4 vs. 266.8 g), the average daily gain during fattening period (217.2 vs. 161.9 g), and feed conversion ratio (7.62 vs. 9.75) in male lambs was better than female lambs (p < 0.05). Fat tail percentage and total carcass fat content in male lambs were higher than that of female lambs (p < 0.05). It is concluded that, Romanov×Lori Bakhtiari crossbred lambs had higher performance than Lori Bakhtiari lambs before weaning. However, fattening period performance and carcass weight in Bakhtiari lambs were higher compared to Romanov×Lori Bakhtiari crossbred lambs. In addition, energy spent per kg of carcass and live weights in Bakhtiari lambs was lower than Romanov×Lori Bakhtiari crossbreds. Therefore, it can be concluded that the indigenous Bakhtiari sheep breed is more useful for fattening than that of Romanov×Lori Bakhtiari crossbreds in Chaharmahal and Bakhtiari province.

Compensatory growth is the overweight that is achieved by providing the animal with access to adequate food after a period of nutritional restriction. Therefore, a livestock that is affected by a period of feed restriction after re-feeding, especially at the beginning of this period, has less maintenance requirements compared to a livestock that has not been affected by the feed restriction period. Considering the feedlot of 320,000 fattening lambs in Lorestan province per year and the possibility of using feed restriction to promote the use of compensatory growth in lamb fattening, the project was carried out aims to investigate the possibility of process changing the growth rate, fattening and physical and chemical composition of carcass lambs Lori breed by short-term strategies of feed restriction.

Twenty male Lori lambs with a mean live weight of 30±1.45 kg were selected for the experiment. The four experimental diets included 1) the control group (fattening diet without restriction and ad libitum); 2) 80% ad libitum group 3) 70% ad libitum group 4) 60% ad libitum group. At the end of experiment, daily weight gain, final weight, feed conversion ratio, feed efficiency and feed intake were calculated and then three lambs were slathered from each treatment. Carcass characteristics were calculated with the cost of production per kg of weight gain, carcass and lean meat. Percentage of dry matter, ash, crude fat and crude protein were determined for meat chemical composition. Performance data, carcass traits and chemical composition of carcass were completely randomized design with four replications (each replication including six lambs and three for carcass traits and carcass chemical composition) by analysis of covariance means of mixed model procedure. Comparison of mean treatments was performed by Tukey test.

Results showed that there were significant difference between the final weight of lambs at the end of feed restriction period (p < 0.05). At the end of the re-feeding, no significant differences were observed among the control treatment with 70% and 80% feed restriction groups (P>0.05). There were significant difference among intake dry matter of lambs at the end of feed restriction period (p < 0.05). At the end of compensatory growth, no significant difference was observed between control and restraint groups. During the re-feeding period, feed conversion ratio was lower in feed restraint treatments compared to control treatment. Feed efficiency was similar to feed conversion during feed restriction and re-feeding period in the experimental groups. Results of physical composition of carcass during re-feeding showed that the average of most carcass traits in control and 80% of feed restriction treatments had no significant difference and were higher than 70 and 60% of feed restriction. Meanwhile, the fat tail weight and percentage and total carcass fat were higher in the control group than in all control groups. The results showed that the percentage of cold carcass lean meat in the compensatory groups was higher than the control treatment. Percentage of carcass chemicals in feed restriction period showed that dry matter, percentage of crude protein and fat in control treatment were higher than feed restriction treatments and there were significant difference among treatments (P <0.05). The percentage of crude protein in the re-feeding period was higher than the control group.

This study showed that lambs with 80% restriction of feed due to higher weight gain, feed conversion ratio were more favorable in terms of fattening condition than control lambs who consumed feed during whole period. Also, this treatment was the total carcass fat percentage lower and lean meat higher and ultimately, the production costs per kg carcass and lean meat were lower than other treatments.

This study was conducted to evaluate the effect of corn particle size and different insoluble fiber sources on performance and carcass and gastrointestinal tract characteristics of broilers from 1 to 21 days of age. A total of 660 male broilers were used in a 2×3 factorial arrangement with 6 treatments and five replicates per treatment. The factors of interest were two corn particle sizes (2 and 6 mm) and three insoluble fiber sources (lignocellulose, rice hull, RH and sunflower hull, SFH). The main effect of fiber source was significant for the body weight gain (P<0.01) and feed conversion ratio, with SFH inclusion improved BWG (P<0.01) and FCR (P<0.01) compared to OH and lignocellulose. The supplementation of lignocellulose (P<0.05) and fine particles (P<0.01) resulted in higher carcass weight compared to other fiber sources and coarse particles, respectively. Feeding lignocellulose increased (P<0.01) the weight of the small intestine than the other two fiber sources. The Experimental treatments had no significant effect on the relative length of small intestinal segments. Coarse grinding of corn and SFH inclusion reduced gizzard pH when compared to fine grinding and lignocellulose inclusion, respectively (P<0.05). The Gizzard weight of birds fed a diet containing lignocellulose and SFH was significantly higher (P<0.01) those fed RH. Generally, the dietary inclusion of 3% SFH improves growth performance through improved weight and reduced pH of gizzard and can be practically used in the broiler industry.