ابوالقاسم گلیان

Pelleting is one of the most common methods of thermal processing for poultry feed. The primary goal of pelleting is to agglomerate smaller feed particles using mechanical pressure, moisture, and heat. Previous studies have shown that pelleted feeds enhance production economics by improving feed efficiency and growth performance. A key step in the pelleting process is conditioning the mash prior to pelleting, which reduces the electrical energy usage (EEU) of pellet mill motors by facilitating the smooth passage of materials through the die press, playing a crucial role in forming high-quality pellets. Additionally, effect on productive performance, reported conditioning temperature is the main factor affect it. Moderate thermal processing of broiler diets causes the separation of protein matrix, starch and fat, gelatinization of starch, destruction of anti-nutritional sensitive to heat and destruction of cell walls, and are considered positive chemical and physical changes in the process of pelleting with steam heat. Thermal processing improves the nutrient value of broiler diets, which usually has beneficial effects on performance. The use of high conditioning temperatures can damage the nutrients in the feed, leading to reduced nutrient intake and decreased bird performance. However, the better physical quality of pellets obtained at higher conditioning temperatures may affect broiler performance depending on the extent of negative effects of conditioner temperature on nutrient availability. Feed form affects the metabolizable energy of broiler pelleting and increases the apparent metabolizable energy of grains. The objective of the current study was to evaluate the influence of conditioning temperature on EEU of the pellet mill motors, feed pellet quality, apparent metabolizable energy corrected for nitrogen (AMEn), and apparent nutrients digestibility in the broiler chickens. A diet were formulated on the broiler Ross 308 strain recommendations bases for grower period. The diet was prepared according to the experimental design, using a completely randomized design (CRD) with 11 treatments and 5 replicates per treatment. The treatments included mash feed, cold pelleting (unconditioned), and pelleting following conditioning at three different temperatures (55, 70, and 85°C), with feed samples collected at three different stages during feed preparation. The diet conditioning was done by conditioner manufactured by Feedtech at steam mixture for 30s and two bar steam pressure and then were pelleted through 2.5 mm die using a pellet mill. The desired temperatures of the conditioner were applied by increasing the volume of steam and continuously measured during the passage of the feed using a digital thermometer. The electrical energy usage (EEU) of the pellet mill motors during the pellet diets predation were recorded. All pellet diets were sampled after production to test for pellet quality. Pellet quality was determined as a function of pellet durability index (PDI), fine percentage and pellet hardness. Durability was determined using a Holmen Pellet Tester (NHP200). The pellet hardness was determined by using a hardness tester. A total of 200 one-day-old male chicks (Ross 308) were purchased from a commercial hatchery, reared on floor covered with wood shavings and the Ross 308 guideline up to 11-day-old. To determine the apparent nutrients digestibility and apparent metabolizable energy corrected for nitrogen (AMEn), two birds were transferred to individual cages (replicate) on day 15 to adapt to cage conditions for 4 days. On d19, birds were subjected to eight hours’ starvation following which collection trays were installed under each cage for excreta collection. Feed intake of the birds in each cage was recorded during the experimental period (19-21d). Total excreta were collected twice daily between 18-21d. Daily collections were immediately dried, pooled within a replicate, mixed, weighed and representative samples ground (0.5 mm sieve), and stored in airtight plastic containers (−20°C) until to analysis. Excreta and diet samples were analyzed for dry matter (DM; method 934.01), crude protein (CP; method 976.06), ether extract (EE; 954.02) according to the standard procedures of the Association of Official Analytical Chemists (AOAC, 2016). Apparent total tract retention coefficient of nutrients for diets were calculated. In addition, the gross energy of feeds and excreta samples were measured using adiabatic bomb calorimeter (Model 1266, PARR) and the apparent metabolizable energy was calculated. The data obtained from the experiment were analyzed in the form of a completely randomized design using SAS software version 9.1 (2003) with the general linear model (GLM) procedure. The respective means were compared with Tukey's test at the probability level (P < 0.05). The effects of processing temperature on EEU of the pellet mill motors, and pellet quality were significant. So that the amount of electricity usage decreased (quadratic, p< 0.001), and increased pellet PDI (quadratic, p<0.001) and pellet hardness (linear, p<0.002) by increasing in conditioning temperature. The highest electricity usage was observed in the treatment without conditioning (cold pellet) and the lowest amount of electricity usage was observed in the 70, and 85C° treatments (P<0.05). The diet dry matter, crude protein and crude fat digestibility and AMEn were affected by processing (P>0.05) so that the highest digestibility rate and AMEn was observed in 70°C heat thermal treatment, which were significantly higher than mash diet. By increasing conditioning temperature, the AMEn and crude fat digestibility improved by quadratic trend (p < 0.05). The heat processing at 70°C and pelleting diet lead to 6.8% and 3.59% improving apparent fat digestibility and 96 kcal/kg (3.46%) and 74 kcal/kg (2.64%) improving in AMEn values than non-processed diet (mash diet) and cold pellet diet, respectively.  Based on the findings of this study, it is recommended to prepare feed in pellet form and apply a conditioning temperature of 70°C. This approach reduces the electrical energy consumption during feed preparation, improves pellet quality, and enhances nutrient digestibility and the apparent metabolizable energy (AMEn) of the diet.

 Feed cost has gradually increased in poultry production worldwide. One approach to minimizing production cost is dietary manipulation of nutrient supplies through improved feed efficiency. The inclusion of lipids in broiler diets is essential to meet metabolisable energy requirement. Great amounts of animal fats and vegetable oils are usually added to broiler diets to increase their energy content. However, several factors can affect lipids digestion, both related to the animal characteristics such as bird age, genetic strain, secretion and activity of digestive enzymes, and to the diet composition such as type of fat used as lipid supplement, ratio of unsaturated to saturated fatty acids in the diet, presence of pentosans and dietary fiber. Within this reality, researches have been conducted to study the increased digestibility of oils and fats by emulsifying substances, such as bile salts and phospholipids. Lysophospholipid (LPL) is a more effective biosurfactant in emulsifying properties than bile salts and soy lecithin because one molecule in the hydrophobic tail is removed, indicating more stability in the aqueous environment of the gastrointestinal tract. Another action of lysophospholipids is related to the antibacterial effect. They may modify the biological structure of bacteria causing changes in membrane permeability, raising the speculation of a combined effect with organic acids on poultry gut health. The changes in membrane permeability by lysophospholipids may facilitate the ion dissociation of the organic acids inside the bacteria. In turn, the control of the intestinal microbiota through these additives could preserve the integrity of endogenous, consequently, the present study was designed to investigate the effects of dietary LPL supplementation in diets differing in fat on blood parameters, intestinal morphology, ceca microbiome and performance in broiler chicks.

This experiment was performed in a completely randomized design based on factorial arrangement to evaluate the effect of lysophospholipid supplementation (0 and 0.25g/kg) in corn-soybean meal diets containing three fat sources (soybean oil, tallow and their blend 50: 50%) and each at two levels (1.5 and 3%) with 12 isocaleric and isonitrogenous starter diets. Each diet was fed to six replicates of 10 chicks each during 1 to 14 days of age. Performance traits, jejunal morphology, serum lipid composition, cecal microbial population of one chick from each replicate were measured at day 14.

the interaction effects of lysophospholipid supplementation, fat source and fat level were not significant on broiler performance during 1 to 14 days of age, except for the lysophospholipid supplementation and fat level that was significant on feed intake in the starter period. Among the main effects only fat levels had a significant effect on body weight, body weight gain in the starter period, and 3% fat level compared to 1.5% improved body weight and body weight gain. These results are in agreement with zampiga et al, (2016) that demonstrated the addition of the lysophospholipid did not statistically improve final body weight and daily weight gain of broilers in the whole period of trial (0–42 d). These observations are partially in contrast with Melegy et al. (2010) who reported that the use of an emulsifier based on lysolecithin at the dosage of 0.25 or 0.5 kg/ton of feed significantly improved these productive parameters. Other factors may be affect on broiler performance such as inappropriate dose of lysophospholipid in diet, low energy levels of the experimental diets, use of 3 factors in the experimental design, and low bird population in each treatment that combined the effects. The Interaction effects of lysophospholipid supplementation, fat source and fat level were not significant on jejunal villus height, villus width, diameter of epithelium layer, crypt depth and villus height to crypt depth ratio. The interaction effects of lysophospholipid supplementation and fat levels in diet showed a significant effect on villus width. The effect of fat levels was significant for villus height and it increased by the use of 3% levels. The Interaction effect of lysophospholipid supplementation, fat source and fat level was not significant on the concentration of triglyceride, cholesterol, HDL and LDL in serum of broiler chicks. The interaction effect of lysophospholipid supplementation and fat level in diet was significant on the concentration of triglyceride level, and the interaction effect of lysophospholipid supplementation and fat source in diet was significant on LDL in serum lipid level of broiler chicks. The main effect of lysophospholipid supplementation was significant on the concentration of triglyceride, and also the effect of fat source was significant on cholesterol and HDL in serum of broiler chicks. The Interaction effects of lysophospholipid supplementation, fat source and fat level was not significant for lactobacillus and E-coli population in ceca. The main effect of lysophospholipid supplementation was significant increase on the lactobacillus population in ceca, and the effect of fat level in diet was significant decrease on the E-coli population in ceca.

It can be concluded in this study that of lysophospholipids supplementation did not have a significant effect on performance in broiler chickens during the starter period.

In recent years, increasing feed costs in broiler production encouraged nutritionists to reduce feeding expenditure, along with maintaining optimal performance of broiler chickens and minimizing environmental pollution. Phosphorus and calcium are two important minerals in the poultry diets, which is necessary to accurately feeding these minerals in the poultry nutrition. Environmental contamination, as a result of over-feeding of phosphorus by poultry, is a matter of concern, which has urged researchers to seek solutions such as reducing dietary phosphorus concentrations without adversely affecting the growth performance. Also, due to the interaction effect of phosphorus and calcium in the gastrointestinal tract, the ratio and balance between these two elements is also important. It has been argued that broiler chicks, when fed by diets containing lower levels of phosphorus and calcium, absorb these materials with higher efficacy and thus reduce their excretion from the gastrointestinal tract. Yan et al. (2005) reported that feeding broiler chickens with diets containing reduced levels of phosphorus and calcium during starter phase, and then using diets containing sufficient levels of phosphorus and calcium, caused better utilization and bone mineralization. Birds respond to dietary phosphorus and calcium content, by increasing the expression of mRNA encoding calcium and phosphorus transporters in the small intestine.More studies are needed to optimize the levels of phosphorus and calcium in the early stages of growth, as well as fine-tuning the appropriate time period for decreasing them with the aim of designing nutritional strategies that increase the utilization of phosphorus and improving the growth performance and mineralization of the bones. Therefore, the aim of this study was to determine the effect of phosphorus and calcium restriction during grower phase and its effect on growth performance, blood and bone parameters and adaptation response in broiler chicks. A total of 648 one-day-old male broiler chicks of the Ross 308 strain were used in this study. The chicks were randomly distributed into floor pens (1.2 m × 1m). During the starter period (1-10 d), all birds were fed with a standard diet containing recommended nutrients of the Ross 308 strain. Then, the experimental diets in the grower period (11-24 d) were included: 1) standard diet as control 2) diets with 15% reduction in available phosphorus (aP) and calcium (Ca) and 3) diets with 30% reduction in aP and Ca. In this period, the control treatment included 6 replicates of 12 chicks, and the other two treatments included 24 replicates with 12 chicks each. On d 25 of age, each treatment group (except control) was divided into 4 treatment groups including 0, 10, 20 and 30% reduction in aP and Ca levels for the finisher period diets; so that a total of 9 dietary treatments with 6 replicates and 12 birds per pen were formed. Average body weight (BW), daily feed intake (DFI), daily weight gain (DWG) and feed conversion ratio (FCR) were measured at the end of grower and finisher periods. On day 24, one bird from each pen, weighing closest to the mean body weight was selected and slaughtered, and the carcass parts, as well as internal organs were weighted and expressed relative to live body weight. Blood samples were taken from wing vein of 5 chicks in each treatment on day 24 and serum Ca, Pi and ALP levels were analyzed. Percentage of ash, Ca, Pi and breaking strength of tibia, were measured at the ages of 24 and 42 days. Data were analyzed as a completely randomized design using the General Linear Model (GLM) procedure in SAS software (SAS, 2009). Statistical significance of differences among treatments was assessed using Duncan’s test when the F-test from the ANOVA was declared significant (P< 0.05). The probability level between 0.05 and 0.1 was considered as a marginal trend toward significance. Linear and quadratic contrast was also investigated in response to dietary calcium and phosphorus reduction at the end of each experimental period (grower and finisher). The results of this experiment showed that none of growth performance parameters were affected by the treatments during the grower, finisher and the whole experimental period. The relative liver weight was increased in a linear trend with dietary calcium and phosphorus reduction at 24 d of age. Similarly, serum alkaline phosphatase level was linearly increased with decreasing of calcium and phosphorus reduction at 24 d of age. Tibia ash, calcium and phosphorus percentage were significantly affected by experimental treatments; so that they were decreased in a linear trend when dietary calcium and phosphorus decreased at 24 and 42 d of age. Tibia breaking strength was not significantly affected at 24 d of age; nevertheless, it had a trend to be significant and was decreased in response to decreasing dietary calcium and phosphorus at 42 d of age. The different response between growth performance and bone characteristics can be due to the fact that calcium and phosphorus requirements are higher for maximum bone function than soft tissues growth. In fact, bone contains 99% and 80% of the body's calcium and phosphorus, respectively. Both act as the main component of hydroxyapatite during the hardening of soft tissue in combination with the organic bone matrix to increase the mechanical strength of bone. The present study showed that reducing the percentage of dietary calcium and phosphorus, despite their significant effect on the blood and bone characteristics of broilers chicken had no significant effect on broilers growth performance. In general, available phosphorus and calcium can be reduced by 15% during the grower period and up to 10% in the finisher period. However, further reduction in the percentage of calcium and phosphorus of diet can lead to adverse effects on the measured traits.

 Wheat is an important cereal due to high starch, available energy and protein contents and is used in poultry diets. Thermal processing is one of the common ways to increase the digestibility of feed, nutritional value of protein through denaturing the anti-nutritional compounds.

 Materials and Methods:

 This project was conducted in two experiments at the Poultry Research Center of Ferdowsi University of Mashhad.

First experiment: 

This trial was designed to determine the apparent metabolizable energy and the digestibility of crude protein and dry matter in four heat treated wheat with and without enzyme supplementation. One hundred twenty mixed sex day-old broiler chicks were fed standard starter (0-10d) and grower (11-15d) diets, 96 of them were divided into 48 groups of two each and randomly assigned to 48 metabolic cages on day 15. Eight diets in which the sole source of energy and protein was wheat, were prepared and each was randomly fed to six replicates of two chicks each from 15-21d. At 18th day of age, 12 hours of starvation were imposed on all chicks; then trays were placed under each cage and feeds were supplied to all cages for 72 hours when the 2nd 12 hours of starvation was imposed and the collection of excreta continued until the end of the second starvation period. The amount of feed consumed by chicks in each cage in three days was determined by the differences of feed supplied and remained. Excreta collected from each cage was placed in a room air flow for 48 hours and then placed in an oven at 60°C for 72 hours to dry completely.Second experiment: in this trial, 576 birds (11d) were divided into two groups, (male and female) from which six males and six females were randomly assigned to one of the 48 pens. To prepare 8 experimental diets, only one grower diet (11-24days) containing 70.11% wheat was formulated based on Ross 308 nutrients recommendation and an untreated and three heat treated wheat with and without enzyme supplementation (Rovabio) were replaced to prepare the 8 diets. The experiment was conducted in a completely randomized design with factorial (2×4) arrangement with 6 replicates of 12 birds each. Diets were randomly assigned to 48 pens in a way that each diet fed 6 replicate birds. On the final day of the trial (24d), one male bird from each replicate group was weighed and slaughtered. The carcass, breast, thighs, back, wings and neck, as well as the weight of internal organs including the heart, spleen, proventriculus, gizzard, liver, pancreas, bursa fabrisius, abdominal fat, duodenum, jejunum and ileum were measured. Duodenum, jejunum and ileum length were also measured. To evaluate the effect of different untreated and heat treated wheat at different temperatures with and without enzyme supplementation on the microbial condition of the digestive contents of the ileum digesta on 24d, about 3 grams of the contents of the ileum region from each slaughtered chicken transferred to the sterile tube containing 9 ml of buffer phosphate and placed in an ice flask and transferred to laboratory.

Results and Discussion:

 Thermal treatment significantly improved the apparent metabolizable energy, digestibility of crude protein and dry matter of wheat, so that the highest apparent metabolizable energy and dry matter of wheat was obtained when wheat was processed at 85°C. Whereas the highest digestibility of crude protein in wheat was obtained at 70°C thermal processing. The effect of enzyme on apparent metabolizable energy, apparent digestibility of crude protein and dry matter of wheat was not significant. The results of this study showed that thermal processing of wheat has a significant effect on feed consumption, daily gain, body weight gain and feed conversion ratio. Whereas the feed conversion ratio in chicks fed with diet containing wheat processed at 70°C was similar to those fed other diets contained heat treated wheat and was significantly better than those fed control diet. Dietary enzyme supplementation had a significant effect on body weight, daily gain and conversion coefficient, so that the daily gain of chicks fed diet containing enzyme was increased by 4.5% and the conversion factor was improved by 4.2% compared to those fednon-enzyme diet. Thermal treatment of wheat significantly affect relative percentage of thigh weight and relative weight of broiler chickens at 24 day age, so that the highest relative percentage weight of thigh and breast was in chicks fed diet contained wheat processed at a temperature of 70°C. On the other hand, thermal treatment of wheat significantly affect the relative percentage of abdominal fat, which increased compared to untreated wheat. Also, the present study showed that processed wheat did not have a significant effect on the percentage of carcass weight, back, wings and neck, liver, pancreas, heart, spleen and bursa. Also, the interaction effect of thermal processing of wheat and enzyme supplementation on the relative weight of carcass, its parts and internal organs was not significant. The supplementation of enzyme had only a significant effect on ileum weight. Thermal processing of wheat at different temperatures had a significant effect on the height and width of villi in jejunum, but did not have a significant effect on the depth of the crypt and villi height to crypt depth. The lactobacillus population in the ileum region has not been affected by the heat treatment of wheat and a negative response to Salmonella infection was observed in all chickens. On the other hand, the use of enzyme supplementation did not have a significant effect on villi height and depth of crypt and villi height to crypt depth. The interaction effect of heat treated wheat and enzyme supplementation was not significant for neither of the measurements.

Conclusion:

 The results of this experiment showed that although thermal processing of wheat at 85°C increased the apparent metabolizable energy by 5.32% and dry matter digestibility by 5.61%. In addition, the inclusion of heat treated wheat in diet led to an increase in height and width of jejunal villi and improvement of feed intake weight gain and feed conversation ratio in broiler chickens.

Soybean meal (SBM) is the main source of protein in broiler diets. Interest has been increased in the use of roasted full-fat soybean (RFFS) as a replacement of soybean meal and fat in broiler diets. The use of full-fat soybean can eliminate the high cost of oil usage and allows the use of a protein supplement in the broiler diets. Full-fat soybeans could provide both protein and energy in one feed ingredient. Use of raw soybeans in poultry diets is not efficient due to presence of anti-nutrient factors like trypsin inhibitor factors. One method of raw soybeans heat processing is roasting the beans by a rotating chamber in which they are directly exposed to a flame. It has been reported similar weight gains by broiler chicks fed heat treated full-fat soybeans or SBM. Heat-treated full-fat soybeans have been included in broiler diets at the level of 15% and reported that body weight at 6 weeks of age were not significantly affected. In contrast, heat-treated full-fat soybeans in starter and finisher diets at the level of 30% reduced growth performance during the starter period. However, the adverse effects became less severe as bird age increases. In some cases weight gain significantly decreased by full-fat soybeans compare to SBM containing diets. When 100% of the soybean meal was replaced by roasted full-fat soybeans, body weight was significantly decreased at 3weeks of age. The high energy of full-fat soybeans may change carcass composition. It has been shown that carcass yield of broiler chickens improved 3% when soybeans were included 10% of the diet. Information about full-fat soybeans for broilers is limited. Therefore, the aim of this experiment was to examine the effects of substituting different levels of roasted full-fat soybean for soybean meal in diets of broiler chickens on performance and blood metabolites.

In order to evaluate the effects of roasted whole soybeans replacement for soybean meal in male broiler chicken diets on growth performance, carcass characteristics and blood parameters, a completely randomized design with four treatments and four replicates was carried out with 192 day-old Ross 308 male broiler chicks up 42 days. In this experiment, RFFS was roasted in 130 centigrade degrees for 30 minutes. All groups were fed with a standard starter diet during 1-14 d. RFFS was substituted in 4 dietary levels of zero, 25, 50 and 75 percent for soybean meal during growing (15-28 d) and finisher (29-42 d) periods. Diets were formulated to be isocaloric and isonitrogenous. Feed and water were provided ad libitum throughout the experiment. Body weight gain, feed intake, and feed conversion ratio (FCR) were measured during grower and finisher periods. Birds were reared on litter floor pens and a lighting program with 23:1 h light and darkness was used from 1-42 d. At day 42 after 3 h fasting, one bird from each replicate close to group mean weight was selected to determine carcass characteristics and blood parameters. Blood samples were taken from the wing vein and serum was separated by centrifugation at 3000×g for five min. The serum samples were kept in -20°C until analysis. Results and Discussion Results showed that 75% level of RFFS replaced with SBM significantly decreased weight gain, body weight at the end of each period and feed intake in grower period. In finisher period the replacement of 75% of SBM with RFFS, resulted lower body weight, daily weight gain and feed consumption in compare to other replacement levels (p < 0.05). FCR in grower period was not significantly affected by treatments but control group in finisher period had better feed conversion ratio compared to other treatments (p < 0.05). Carcass parts including breast, thighs and pancreas were not significantly affected by the treatments. But, liver and abdominal fat pad weights were increased when the FFSM level was increased to 75% substituting level (p < 0.05). RFFS had no significant effects on blood serum triglycerides, low density lipoproteins, lactate dehydrogenase and alanine transaminase concentrations. But, blood serum cholesterol and high density lipoproteins (HDL) concentrations in control group were significantly lower than other treatments. Serum aspartate transaminase concentration in 75% replacement level of RFFS for SBM was significantly lower than other treatments (p < 0.05). Serum creatine phosphokinase concentration in control group was significantly (p < 0.05) lower than other groups.

of this experiment revealed that replacement of 50% of diet SBM with RFFS during 15-42 days of age has no adverse effect on broiler chickens growth performance and increases blood HDL.

Introduction:

The digestion and absorption of dietary fats involve processing of insoluble triglycerides in water, which is done by bile activity to emulsify the fats and then to hydrolyze them by lipase. Lipid digestion is not optimal, especially in young birds and it is improved with increasing age; this is due to the low capacity of the digestive system in the secretion of lipase and bile acids, so that the lipase function in one-day-old chickens is one percent of its activity in 21 days of age. Emulsifiers can distribute fat droplets in the emulsion, which is required for the digestion and absorption of fats. Lysophospholipids increase the ability of the emulsion of the fat in the diet and facilitate the development of the chylomicron and, as a result, it increases the digestive capacity and absorption of lipids, such as essential fatty acids and lipid soluble vitamins in the small intestine. The purpose of this study was to estimate the added value of lysophospholipid supplement in corn-soybean diets and its added effect on metabolizable energy (ME) of different types of fat during the growth period of broiler chicks.

Materials and methods:

 Three hundred and fifty day-old male Ross 308 broiler chicks were obtained from a commercial hatchery unit. First, the whole chicks were kept in the pan for up to 14 days of age and fed with standard starter (1-10 days) and grower (11-14 days) diets. At 15 d of age, 288 chicks were divided into 144 two-part groups, then they were transferred randomly to metabolic cages and fed with experimental diets. The trial was conducted in a completely randomized design with factorial arrangement of two lysophospholipid (0 and 250 g/ton) levels, three fat sources (soybean oil, tallow and their mix) and four levels of fat (0, 3, 6 and 9 % replaced in diet) with 6 replicates of 2 male birds each. Twelve experimental diets were prepared by replacing and mixing four levels of soy oil, tallow and/or their mixture (50:50) in the basal diet. Then, each diet was divided into two equal parts; one part was mixed with 0.25 g/kg of supplemental lysophospholipid and the other one was kept intact to make 24 diets.

Results and Discussion:

 According to the different ratio of saturated fatty acids to unsaturated fatty acids (SFA: UFA) between tallow (33:60) and soybean oil (16:84), it is known that saturated fatty acids are less digestible in animal fats compared with fatty acids of vegetable oils. Addition of supplemental lysophospholipid did not have any significant effects on dietary ME, digestibility of dry matter (DM) and crude fat (CF). The interaction effect of the replacement level and the sources of fat was significant for the ME of diet, in which the basal diet with 9 percent soybean oil replacement had the highest ME compared to the other levels and the other fat sources. Two and three way interactions were not significant for ME and digestibility of dietary DM and CF. No significant effect of lysophospholipids on the digestibility of dietary nutrients using 1 and 1.5 g/kg of diet. The effects of lysophospholipids on the digestibility of nutrients depend on factors such as the difference in the base diet, especially in ingredient, the composition and ratio of fat in the diet and the emulsifier (lysophospholipid), which can lead to different responses. Soybean oil had the most ME among the sources of fat. The ME of soybean oil, tallow and their mixture was determined using replacement method to be 8367, 6134 and 6547 kcal/kg, respectively. Studies have shown that the degree of saturation, the amount of free fatty acids, and the position of fatty acids on the glycerol basis affect utilization of fat by the bird. Possibly, the effect of lipophospholipids on the digestibility of crude fat from diets containing tallow can complete the function of bile salts. In normal conditions, there is little effect on high amounts of saturated fatty acids. The lysophospholipid supplementation improved the ME of various sources of fat about 596.4 kcal/kg. The estimated added value (matrix) of lysophospholipid supplement for ME in each kilogram of soybean oil, tallow and their mixture, were 157, 43 and 211 kcal/kg, respectively.

Conclusion :

The results of this study showed that the lysophospholipid supplementation increased the ME of supplemental fats but had no significant effect on the ME, digestibility of DM and CF in diet.

[1] Increasing feed costs are significant issues in the poultry industry. Therefore, poultry producers often interested to feed low energy and nutrient dense diets to reduce production cost, while low energy and nutrients dense diets may not appear to supply sufficient energy for laying hens. Hens can regulate their feed intake to maintain energy and nutrient intake in accordance with their requirements. In this way, hens will consume more of a low energy and nutrients dense diet than of a high energy and nutrients dense diet, ensuring the calories and nutrient consumed be sufficient. However, some studies have shown that hens especially the modern ones are not precise in adjusting their feed intakes, such as the Hy-Line W-36, since they only have a limited capability to increase their feed intake to ensure adequate energy and nutrients intake. While low energy and nutrient dense diets are less expensive to purchase, they may not ensure optimal egg production if hens are unable to adjust their feed intake. On the other hand, the purchase price of low energy and nutrient dense diets can be substantially lower than high-density diets, if they are effective in maintaining long-term egg production performance, so that can result in increased returns for the producer. Thus, feeding low energy and nutrient dense diets to laying hens may result to improve returns due to a lower cost of diets. However, it has been shown that the increased efficiency of birds fed on high energy and nutrient dense diets can offset the higher cost of feed. The hypothesis of this study was to investigate how Hy-Line W-36 laying hens in post molting period can respond to lower energy and nutrients dense diets, through their increase in feed intake to maintain energy and nutrient consumption to support egg production.

The birds that used for this experiment were molted at the 70wk of age on a non-fasting feeding program according to the molting recommendation by Hy-line W36 laying hens guide. Three hundred twenty 78wk Hy-Line W36 hens were individually weighed and randomly assigned to 80 cages of four birds each. Eight replicate groups of 8 hens each (two adjacent cages) were randomly assigned to each of the 5 treatment diets with location within house as blocking criteria. The pre-experimental period was two weeks for acclimatization, and the experimental period was from 92-103 weeks of age (three 28d periods; 92-95, 96-99, 100-103wk of age). Experimental diets were formulated according to the guidelines in the Hy-Line W-36 Commercial Management Guide (2015) for 104g feed intake according to the average pre-experimental period egg production and feed intake data. Thus the control diet (100% of recommendation) was formulated to contain 2845 kcal/kg AMEn; 14.42% CP; 4.14% calcium; 0.48% available phosphorus; 0.17% sodium; 0.67% digestible lysine; 0.36 digestible methionine; 0.56 digestible methionine + cysteine; and 0.47 digestible threonine. Four other dietary concentrations of energy and nutrients density were formulated to provide 91, 94, 97, and 103% and one diet with the 100% of recommendations stated in the 2015 Hy-Line W36 commercial management guide. Egg production (number and weight) and mortality were recorded daily, whereas feed consumption was measured every 4wks as feed disappearance. Six eggs/replicate (48 eggs/treatment) laid in the last 72 h of each 28d period were collected and transported to Egg Quality Laboratory at the Ferdowsi University for of egg weight, albumen, yolk and shell relative weight, Haugh units, egg shape index, egg special gravity, and shell thickness determination. The feed cost/kg egg production was calculated by feed costs time feed conversion ratio. Data were analyzed by ANOVA using the GLM procedure of SAS 9.1 (2003), with dietary treatment and block as independent variables. Diet effects were evaluated using linear and quadratic orthogonal polynomial contrasts. The linear broken-line (LBL) and quadratic-broken line (QBL) regression models were used to estimate the dietary energy and nutrient density ratios for optimization of egg mass and feed conversion ratio.

Previous research showed that hens would linearly adjust their feed intake in response to diet nutrient density by eating significantly more feed that was low in energy and less feed that was high in energy. These changes in feed intake were not in agreement with the results of the current study showed that egg production, and egg mass were increased and feed conversion ratio (FCR) decreased significantly and linearly, with the increase in dietary energy and nutrients density. There was not any significant difference in the egg production, egg mass and feed conversion ratio in birds fed diet containing three percent (103%) more nutrient density than that of strain recommendation. Whereas, feed intake, egg weight, white yolk and shell relative weight, egg shape index, specific gravity, egg shell thickness as well as Haugh unit were not significantly affected by dietary energy and nutrients density. Significant linear increase due to increase in energy and nutrients density were observed for most measured parameters, including hen-day egg production, egg weight, egg mass, feed efficiency, energy intake, and body weight gain. The hen-day egg production showed that hens fed diets containing 91% of control diet laid fewer eggs than those fed diets with 100 or 103% of nutrients recommendation. The energy and nutrient requirement for optimal egg mass (g/b/d) and FCR during the post molting period (92-103Wk) by LBL model were 94.96 and 97.02%, and by QBL model 95.71 and 95.95% of strain recommended, respectively.

In summary, the increase in energy and nutrients density in diet of Hy-Line W-36 laying hens increased egg production, egg weight, egg mass, energy intake as well as decreased body weight losses and feed conversion ratio. The regression analyses of data showed that, laying hens diet formulated at the 95-97% of nutrients recommendation had the optimal egg production and economic performance during the second egg production cycle. Furthermore, hens were unable to adjust their feed intakes since the lowest energy and nutrients density diet deteriorate egg production performance.

The aim of this study was to investigate the effect of finisher diet nutrient density and slaughter age on energy and protein retention efficiency of broiler chickens. Three hundred 23-day-old Cobb-500 male broiler chickens were assigned in a 5×2 factorial arrangement of completely randomize design with 10 treatments, 6 replicates and 5 birds each. The experimental treatments included five nutrient levels of finisher diets (102.5, 100, 97.5, 95, and 92.5% levels of nutrient composition recommendations stated by the Cobb-500 Commercial Management Guide) and two slaughtered ages (38 and 46 days of age). As increased dietary nutrient density significantly and l inearlyincreased weight gain, feed efficiency, energy and protein retention efficiency and decreased maintenance energy requirements per unit of weight gain (P<0.05). By increasing slaughter age from d38 to d46, above indices significantly deteriorated (P<0.05). The highest residual feed intake belonged to birds fed the finisher diet with 97.5% of strain recommendation nutrients level. Dietary nutrient density level for optimal weight gain, feed efficiency, and energy and protein retention efficiency by linear broken line models were estimated 101.7, 98.7, 97.7 and 99.5% of strain recommendation, respectively. Whereas, these values were 2.3-5.5 percent less than those estimated by the quadratic broken-line model. As a conclusion, residual feed intake methodology can be a viable alternative to measure dietary energy efficiency. Formulation broiler finisher diet with nutrients concentration lowers than 97.5% of strain recommendation is not suitable.

Adjuvants are an essential component of modern vaccines. An adjuvant is an entity added to a vaccine formulation to ensure that robust immunity to the antigen is inoculcated. The adjuvant is typically vital for the efficacy of vaccines using subunit (pepdids, proteins and virus like particles) and DNA antigens. Furthermore, these components are used to reach the current new goals of preventing and/ or treating chronic infectious diseases and cancers. This review focuses on formulation aspects of adjuvants, safety considerations, progress in understanding their mechanisms of action and also their side effects with using 97 articles are acceceble in pubmed central and google scholar indexing which published during 1980-2016. Adjuvants can be broadly divided into two classes, based on their principal mechanisms of action; the first class are vaccine delivery systems that generally particulate and mainly function to target associated antigens into antigen presenting cells. The others are immunostimulatory adjuvants that predominantly derived from pathogens and often represent pathogen associated molecular patterns which activate cells of the innate immune system. Adjuvants induce cellular and humoral responses, in particular neutralizing antibodies that able to inhibit the binding of pathogens to their cellular receptors. Efficient Th1-immunity-inducing adjuvants are highly in demand. The adjuvants promote good cell-mediated immunity against subunit vaccines that have low immunogenicity themselves. However, attempts to develop a new generation of adjuvants, which are essential for new vaccines, is important, but their use is limited because, little is known about their mechanisms of action and health risks.

This experiment was conducted to evaluate the effect of varying levels of digestible protein (DP) and dietary electrolyte balances (DEB) during the finisher period on performance, blood parameters and small intestine histology of broiler chickens exposed to heat stress. A total of 500 mixed sex chickens (Ross 308) were used in a completely randomized design as a 2×5 factorial arrangement with two levels of DP (%16.5 and %19) and five levels of DEB (150, 200, 250, 300 and 350 meq/kg of diet)with five replicates of 10 birds each during the finisher period. The chicks were exposed to heat stress of 32±2 °C for eight hours/day during 28-42 days of age. Increasing DP levels did not have a significant effect on weight gain under heat stress during the finisher period. Feed intake and feed conversion ratio (FCR) of chickens fed 16.5% DP diet was significantly more than 19% DP fed birds (P0.05) on small intestine morphology. Diet containing 250 mEq/kg of diet EBD significantly (P