Effect of dietary levels of rapeseed meal and polyethylene glycol on the performance of male broiler chickens

1. In a 5 × 2 factorial experiment, the performance of male broiler chickens given starter (1 to 21 d) and finisher (21 to 42 d) diets containing five concentrations (0, 74.5, 149.0, 223.5 and 298.0 g/kg) of rapeseed meal (RSM) and two concentrations (0 and 15 g/kg) of polyethylene glycol (PEG) was measured.

2. Bodyweight gain and food intake decreased (P<0.01) with increasing dietary RSM both in the starter and finisher phases.

3. The relative weights of thyroid glands, liver, heart and the ratio of water to food intake increased (P<0.01) while the dressing percentage, abdominal fat‐pad weight and the feather condition score decreased (P<0.01) with increasing dietary RSM.

4. The mortality rate was increased (P<0.05) on diets containing 149 g/kg or more of RSM. The main causes of deaths and culling on the high RSM diets were enlarged livers and hearts, liver haemorrhage and leg disorders.

5. The inclusion of 15 g/kg PEG in the starter diets increased (P<0.01) bodyweight gains and food intake. It also increased (P<0.05) water consumption between 37–39 d, faecal moisture content at 40 d and the haemoglobin content in blood.

6. There were no interactions between the dietary concentrations of RSM and PEG on growth and other variables measured.     

The dietary effect of different wheat cultivars for broiler chickens.

1. An experiment was conducted to examine the variability in chemical composition of 16 wheat cultivars and to study how this variability affected the performance of broiler chickens given diets containing 650 or 815 g wheat/kg diet during the first 3 weeks of life. Intestinal viscosity, apparent fat digestibility and apparent metabolisable energy were determined with all diets. Intestinal pH and the relative weight of different parts of the intestine were measured in chickens fed on diets with the high wheat inclusion. 2. The 16 wheat cultivars varied in chemical composition, with protein content ranging from 112 to 127 g/kg dry matter, starch content from 658 to 722 g/kg dry matter and non-starch polysaccharides from 98 to 117 g/kg dry matter. The effect of the different wheat cultivars on the measured parameters was most pronounced in chickens fed on diets with 815 g wheat/kg diet (P<0.001). However, significant (P<0.001) differences between cultivars were still present at the lower wheat content. 3. Milling-quality wheats resulted in better performance (P<0.001) than feeding-quality wheats at the high inclusion, whereas such an effect could not be registered in diets at the lower wheat inclusion. These results indicate that some of the feeding wheats are comparable in quality to milling wheats when included at the concentrations which are more common in practical broiler diets. 4. Decreasing the wheat content in the diets resulted in significantly (P<0.001) better performance and considerably (P<0.001) lower intestinal viscosity (jejunum; 2.4 to 5.9 cps, ileum; 4.6 to 10.9 cps) than in chickens fed on diets with the higher wheat inclusion level (jejunum; 9.1 to 38.4 cps, ileum; 20.8 to 82.0 cps). 5. Diets with 815 g wheat/kg influenced pH in the caeca, but not in the ileum and gizzard. The relative weights of the gizzard and ileum differed significantly (P<0.05) between treatments, whereas those of duodenum, jejunum and caeca were not affected by dietary addition of the different wheat cultivars. 6. The present study demonstrated that the chemical composition and the nutritive value of Danish wheats for broilers vary markedly. The results indicated that the non-starch polysaccharide and especially the arabinoxylan content of wheat are important factors in the discussion of the result obtained. Poor correlations were seen between performance and AMEn and care should be taken when using AMEn values alone to predict the nutritive value of wheat and wheat-based diets.     

Effect of dietary mannanase‐hydrolysed copra meal on growth performance and intestinal histology in broiler chickens

We investigated mannanase‐hydrolysed copra meal (MCM), which contains β‐1,4‐mannobiose (MNB), for its capacity to improve growth performance and activate intestinal villus function. Seven‐day‐old chicks were separated into four flocks with an equal mean body weight and then fed a basal diet (control) or a diet supplemented with 0.02% or 0.1% MCM. After 7 weeks, the feed intake and body weight were determined and then used to calculate the feed efficiency (FE). Moreover, the intestinal segments were examined by light microscopy and scanning electron microscopy (SEM) for cellular and morphological changes in the villus. Although feed intake was not significantly different among the experimental groups, the body weight gain and FE were significantly higher in the 0.1% MCM group than in the control group (p < 0.05), while feed intake tended to be higher in the 0.02% and 0.1% MCM groups. The cellular area of the ileum was significantly higher in the 0.02% and 0.1% groups in relation to that in the control group (p < 0.05). Furthermore, the cellular area of the duodenum and the jejunum tended to be higher in the 0.02% and 0.1% MCM groups. For the correlation analysis, a significant correlation was observed between the dosage of MCM and the cell area of the duodenum, jejunum and ileum. Moreover, the number of mitotic cells was higher in the 0.1% MCM group. As shown by SEM, the cells at the villi tips were protuberant in appearance in the 0.02% and 0.1% MCM treatments when compared with the relatively flat cells of the control. On the duodenal villus surface of the 0.1% MCM group, some cells devoid of microvilli were observed, suggesting that the increased protuberance of these cells represents increased absorption activity. Although intestinal villus height and area did not significantly differ among groups, the levels of these parameters tended to increase in the experimental groups relative to the control. The present morphological findings reveal that MNB might be effective for activating intestinal absorptive function, and that the functional activation promotes the growth of the chickens.     

不同营养水平饲粮中添加饲用复合酶对肉鸡生产性能的影响

试验用360只1日龄艾维茵肉鸡,采用二因素D-饱和最优设计,考察不同营养水平饲粮及复合酶添加量对肉鸡生产性能和养分利用率的影响。饲粮营养水平在基础日粮的水平上用谷壳进行稀释,能量、蛋白质及氨基酸水平分别降低0%～11.51%;复合酶的添加量为0%～0.23%。复合酶制剂添加量和饲粮营养水平都是影响肉鸡生产性能的重要因素。降低饲粮营养水平显著降低肉鸡增重和饲料转化效率(P<0.05);复合酶制剂添加量对肉鸡的生产性能和养分利用率呈二次曲线关系(脂肪利用率除外)。复合酶的适宜添加量为0.1%。低营养水平时复合酶作用效果更大。复合酶的表观能值与营养水平有关,低营养水平时复合酶的表观能值越高。在本试验条件下,添加0.1%复合酶,饲粮营养水平可降低5%左右。     

Stability of dietary ascorbic acid and the effect of supplementation on reproductive performance of broiler breeder chickens

1. The purpose of the study was to determine the stability of dietary ascorbic acid and the reproductive responses of broiler breeder chickens to supplemental 75 mg ascorbic acid/kg diet. 2. Six breeder flocks of 13,000 birds each were studied. Egg production, eggshell porosity, fertility, hatchability and plasma ascorbic acid were measured. 3. Storage of the diets under dry heat resulted in a linear decrease in ascorbic acid content and the rate of decline was 5-fold higher in the supplemented diet. 4. Differences were not detected between treatments in egg production, egg weight, eggshell porosity, fertility, hatchability or plasma ascorbic acid. 5. The results did not provide evidence of a beneficial reproductive response to the inclusion of ascorbic acid in commercial broiler breeder diets.     

Effects of different sources and levels of dietary chromium supplementation on performance of broiler chicks

The current experiment was carried out to evaluate the effect of different dietary chromium supplementation sources, chromium oxide (Cr₂O₃), chromium methionine (Cr‐Met), or chromium yeast (Cr‐yeast), at different levels each (500 or 1,000 ppb) on growth performance, physiological traits, and carcass characteristics of broiler chicks. A total of 490 seven‐day‐old Arbor Acres chicks were randomly distributed into 7 experimental groups each in 10 replicates of 7 birds each. The groups were control, 500 ppb Cr₂O₃, 1,000 ppb Cr₂O₃, 500 ppb Cr‐Met, 1,000 ppb Cr‐Met, 500 ppb Cr‐yeast, and 1,000 ppb Cr‐yeast. The results showed significant superiority of the organic chromium sources (Cr‐Met or Cr‐yeast) concerning body weight and weight gain, the group supplemented with 1,000 ppb Cr‐yeast consumed the lowest feed (3,185 g) and had the best feed conversion ratio (1.60) compared to the control (1.73). The chromium treatments recorded significantly better protein and lipid profile, antioxidant status, and immunological parameters than the control group. Similarly, dietary chromium supplementation increased carcass yield and decreased intestinal pathogenic bacteria. In conclusion, supplementing broiler diets with organic chromium sources at 1,000 ppb promotes growth performance, physiological traits, and carcass characteristics; such chromium treatments enhanced the antioxidant status and immunity levels of broilers.     

Comparative effect of dietary supplements on the performance and severity of experimental Eimeria tenella infection in broiler chickens

Tropical Animal Health and Production - This study evaluated the productive and reproductive performance of Charolais cows with different body mass index (BMI) at calving and the development of...     

Effect of dietary inclusion of graded levels of toasted guar meal on performance,nutrient digestibility,carcass traits,and serum parameters in commercial broiler chickens

An experiment was conducted in a completely randomized design to explore the replacement value of toasted guar meal (TGM) for soybean meal (SBM) in commercial broiler diets. Hypothesis was tested by including graded levels (0, 6, 9, 12, 15, and 18% of diet) of TGM to replace maize-SBM on growth performance, apparent nutrient digestibility, carcass traits, and serum parameters. A total of six iso-nitrogenous and iso-caloric diets were prepared, and each diet was fed ad libitum to 12 replicates of five chicks each from 1 to 42 days of age. Results showed that inclusion of TGM up to 12% in broiler diets did not affect the body weight gain, feed efficiency, and energy digestibility. Feed intake, dry matter, nitrogen digestibility, and relative weights of ready-to-cook yields, breast muscle, abdominal fat, liver, and pancreas were not affected (P > 0.05) by incorporating TGM even up to 18% in broiler diets. Concentration of glucose, total protein, and triglyceride in serum was also not affected (P > 0.05), while serum total cholesterol concentration was found to be higher (P < 0.05) in broilers fed diets containing TGM as compared to those fed on 0% TGM diet. From the results, it was evident that TGM may be incorporated up to 12% in commercial broiler diets for better growth performance, nutrient digestibility, and carcass traits.     

Effect of different dietary ideal protein concentrations on broiler performance

1. The aim of the study was to examine the response of male broilers of different age categories to different dietary ideal protein (IP) concentrations and to compare the effects to IP recommendations based on single lysine (Lys) requirement studies from the literature. 2. Two experiments were carried out, in which diets containing different IP concentrations (9.0 to 14.4g apparent faecal digestible (AFD) Lys/kg) were fed to male broilers from 14 to 34 (Exp. 1) and 28 to 41 d of age (Exp. 2). The diets (12.88MJ AMEN/kg) were prepared by the dilution technique. The effect of dietary IP concentrations on weight gain, feed intake, feed conversion efficiency (FCE) and slaughter characteristics were studied in both experiments. 3. In Exp. 1, weight gain and FCE increased linearly and fat concentration in the carcase decreased with increasing IP concentration. In Exp. 2, weight gain and FCE improved exponentially, whereas breast meat yield improved linearly with increasing dietary IP concentration. On the basis of these results, it was concluded that the weight gain and FCE of male broilers respond to higher dietary IP levels than would be expected from single lysine requirement studies in the literature.     

Effects of different dietary sources and levels of selenium supplements on growth performance,antioxidant status and immune parameters in Ross 308 broiler chickens

1. Although different impacts of various sources of selenium (Se) on chicken performance have been largely studied, there is a lack of comparative experiments studying the effects of these sources on the immune system and antioxidant indices of broiler tissues. The aim of this study was to examine the effects of various sources and levels of dietary Se supplements on performance, antioxidant status and immune parameters in Ross 308 broiler chickens.

2. A total of 1200 1-d-old male broilers (Ross × Ross 308) were divided into 8 treatments with 6 replicate pens and 25 birds per pen. This experiment was conducted as a completely randomised design with a 4 × 2 factorial arrangement. Main factors included Se sources as sodium selenite (SS), Se-enriched yeast (SY), DL-selenomethionine (SM) and nano-selenium (NS) and levels at 0.1 or 0.4 mg/kg Se.

3. Dietary supplementation of organic Se sources significantly improved average daily gain (ADG), gain: feed ratio and European production efficiency factor (P < 0.05) compared to birds fed on diets supplemented with inorganic source. In addition, ADG was increased in response to increased level of supplemental Se. Based on contrast comparison, there were significant differences in these parameters between organic versus inorganic sources of Se. However, there was no difference between contrast comparisons of NS versus SM and SY.

4. Total anti-sheep red blood cell (SRBC) and Immunoglobulin G (IgG) titres and hypersensitivity were enhanced by increasing supplemental concentration of Se and using organic sources of Se rather than SS (P < 0.05).

5. Oxidation resistance assessment of tissues demonstrated that supplementation of organic sources of Se and increase in supplemental concentration of Se ameliorated glutathione peroxidase activity, total antioxidant capacity and malondialdehyde formation (P < 0.05). Mostly, there were significant differences between organic versus inorganic sources of Se in oxidation resistance.

6. Overall, dietary supplementation of 0.4 mg/kg Se from an organic source resulted in better production performance and immune system response. Moreover, minimum formation of malondialdehyde in broiler tissue was observed in birds fed on diets supplemented with SM at 0.4 mg/kg.

7. It can be concluded that SM is more effective than other sources of Se in reducing lipid oxidation.     

The effect of different dietary levels of a n-paraffin-grown yeast on the growth and food intake of broiler chicks

Sixteen groups, each of about 30 male or female Ross 1 chicks, were given pelleted diets containing 0, 5, 10 or 20% yeast in place of herring meal. The diets were given from 1 d of age for 4 weeks; from 4 to 8 weeks the birds were given a common broiler finisher diet. Replacing up to 10% herring meal by yeast did not significantly affect live‐weight at 4 weeks of age but food conversion efficiency was poorer with the diet containing 10% yeast. Birds given the diet containing 5% yeast to 4 weeks of age were significantly heavier at 8 weeks. The diet with 20% yeast significantly depressed growth at 4 and 8 weeks of age.

The use of yeast in broiler finisher diets was investigated in a second experiment. Birds similar to those used in the first experiment were given diets containing yeast at levels of 0, 5, 10 or 20% from 4 to 8 weeks of age. Live‐weight at 8 weeks was not significantly affected by level of yeast in the diet; food conversion efficiency was significantly better with the 20% yeast diet. Blood plasma uric acid levels were not affected by the level of yeast in the diet.     

Effect of different non-chloride sodium sources on the performance of heat-stressed broiler chickens

1. One hundred and eighty 1-d-old broiler chicks were used to evaluate the effect upon broiler performance during severely hot summer months of three different sodium salts: sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3) and sodium sulphate (Na2SO4), in starter and finisher diets having an identical electrolyte balance (DEB) of 250 mEq/kg. 2. The non-chloride sodium salts were added to contribute the same amount of sodium and were substituted at the expense of builder's sand in the basal diets containing common salt (NaCl) as Na and Cl source. 3. Each diet was fed to three experimental units having 15 chicks each until 42 d of age. Severe heat-stress conditions, maintained in the rearing room, were indicated by high average weekly room temperature (minimum 29.3 degrees C; maximum 38.0 degrees C). 4. Diets containing sodium salts gave better body weight gain, feed intake and feed to gain ratio than the control diet. Sodium salts also enhanced water intake as well as water to feed intake ratio. This effect was more pronounced in broilers fed NaHCO3 supplement (with NaCl in the basal diets). 5. The increased water intake resulted in lower body temperature in heat-stressed birds fed NaHCO3 supplemented diet than in birds fed other sodium salts. A lower mortality rate was noted with NaHCO3 (15.15%), Na2CO3 (13.64%) and Na2SO4 (15.15%) supplements than with the control (33.33%) treatment. 6. Better carcase and parts yield were observed in sodium supplemented broilers. Sodium salts reduced the alkalotic pH and enhanced the blood sodium content, which ultimately improved the blood electrolyte balance and overall performance of heat-stressed broilers. 7. Supplementing broiler diets with sodium salts improved the live performance of heat-stressed broilers and better productive performance was noted with NaHCO3 than other sodium supplements.     

Effects of dietary concentrations of methionine on growth performance and oxidative status of broiler chickens with different hatching weight

1. A study was conducted to evaluate the effects of two hatching weight (HW) levels and two dietary concentrations of methionine on the growth performance and oxidative status of broilers. Male Arbor Acres chickens were divided into two groups on their HW (low and high HW, H and L). Each HW group was then distributed into two subgroups, of similar HW, receiving either low or high dietary concentrations of methionine (4.9 g methionine/kg, LM; 5.9 g methionine/kg, HM). Thus, all day-old birds were distributed into 4 treatments (H-LM, H-HM, L-LM, L-HM) × 6 replicates × 10 birds for 21 d.

2. Broilers with high HW were heavier than those with low HW during the 21 d assay, which appeared to result from increased body weight gain rather than improved feed conversion efficiency. A higher dietary concentration of methionine (5.9 g/kg) improved growth performance of broilers with low HW in terms of body weight gain and feed conversion ratio.

3. Broilers with different HW had similar antioxidant status both in serum and liver.

4. Broilers given a diet containing 5.9 g/kg methionine had enhanced serum superoxide dismutase (SOD) activity and decreased hepatic malondialdehyde (MDA) content at day 7.

5. Broilers given a diet containing 5.9 g/kg methionine had a higher hepatic reduced glutathione (GSH):glutathione disulphide (GSSG) ratio than those given a diet containing 4.9 g/kg methionine at day 21. High dietary methionine concentration reduced hepatic GSH content and glutathione peroxidase (GPX) activity of broilers with high HW at day 7 and at day 21, respectively, but increased hepatic GSH content of broilers with low HW at day 7.

6. Although broilers with different HW had similar oxidative status as indicated by several parameters in blood and liver, HW can have positive effects on the subsequent growth performance of broilers, and a higher dietary methionine concentration (5.9 g/kg) can improve growth performance and antioxidant status in broilers exhibiting low HW.     

Effect of dietary phosphorus concentration and electrolyte balance on the growth performance of broiler chickens

The performance of 1680 male and female broiler chickens given diets with either a low (4.7-4.3 g/kg) or high (8.9-8.2 g/kg) content of inorganic phosphorus and four (150, 200, 250 and 300 mEq/kg) electrolyte balances (Na+K-Cl) was measured from 1-d-old to 49 d of age. Diets with the higher concentration of inorganic phosphorus reduced body weight gains in the starter (P less than 0.01) and finisher (P less than 0.05) phases but the efficiency of food utilisation was reduced only in the starter phase (P less than 0.05). The reduction in body weight gain was greater in males than in females. The growth depression caused by the higher concentration of inorganic phosphorus in the finisher diets was partially alleviated by increasing the electrolyte balance to either 250 or 300 mEq/kg diet. The higher concentration of inorganic phosphorus significantly reduced the dressing percentage and increased the abdominal fat pad weight and litter moisture content. Electrolyte balance had no significant effects on efficiency of food utilisation, abdominal fat pad weights or litter moisture content. Neither the dietary concentration of phosphorus nor the electrolyte balance had a significant effect on mortality or ash content of the tibia.     

三氯化铬对肉仔鸡生产性能和胴体性能的影响

本试验研究日粮中添加三氯化铬(CrCl3)对肉仔鸡生产性能和胴体性能的影响.选用144只1日龄体重均一、健康的艾维菌肉仔鸡,随机分成6组,每组设3个重复.试验期分别饲喂6种不同饲粮1组为对照组,喂基础日粮;2～6组为三氯化铬组,分别在基础日粮中添加0.5、1.0、1.5、2.0、2.5 mg/kg三氯化铬.试验结果表明日粮中添加1.5～2.0mg/kg三氯化铬均能显著提高肉仔鸡增重(P＜0.05),显著改善肉仔鸡的饲料效率和胴体性状(P＜0.05).     

The effect of volatile oil mixtures on the performance and ilio-caecal microflora of broiler chickens

1. The aim of this study was to investigate the individual and combined effects of rosemary, oregano and fennel volatile oil (FVO) supplementation on the performance and ilio-caecal bacteriological flora of broiler chickens.

2. A total of 800 male Ross-308 broiler chickens were divided equally into 8 groups; each contained 100 chickens. The study included a control treatment (NC) with no dietary additives that was supplemented with oils according to the following 7 treatments: 200 mg α-tocopherol acetate/kg (PC), 100 mg oregano volatile oil (OVO)/kg, 100 mg rosemary volatile oil (RVO)/kg, 100 mg FVO/kg and an equal mixture of oregano+rosemary+fennel VO (100, 200, 400 mg/kg, VOM-1, VOM-2 and VOM-3, respectively). The experiment lasted for 6 weeks.

3. At the end of the experiment, dietary supplementation with α-tocopherol, oregano, rosemary and FVO and two different volatile oil mixtures (VOMs) (VOM-2; VOM-3) significantly increased the body weights (BWs) of broilers at 7, 14 and 21 d of age compared to the negative control (NC) (?) and VOM-1 groups. At 0–42 d, birds fed on VOM-3 were considerably heavier and also gained more weight than NC (?) and VOM-1 groups.

4. The blend of VOs at 400 mg/kg significantly increased Lactobacillus spp. in faeces. The blends of oregano, rosemary and FVOs (VOM-3) at 400 mg/kg concentration and also VOM-3 group exhibited stronger antibacterial activity against coliform bacteria compared to the NC (?) group.

5. In conclusion, the blend of oregano, rosemary and fennel VOs at higher concentrations (400 mg/kg concentration) in diets can be used to stimulate the growth and can improve the intestinal microbial balance (including a reduction of coliform bacteria and an increase in Lactobacillus spp. counts) of broiler chickens.

     

Effect of particle size distribution of maize and soybean meal on the precaecal amino acid digestibility in broiler chickens

1. Herein, it was investigated whether different particle size distributions of feed ingredients achieved by grinding through a 2- or 3-mm grid would have an effect on precaecal (pc) amino acid (AA) digestibility. Maize and soybean meal were used as the test ingredients.

2. Maize and soybean meal was ground with grid sizes of 2 or 3 mm. Nine diets were prepared. The basal diet contained 500 g/kg of maize starch. The other experimental diets contained maize or soybean meal samples at concentrations of 250 and 500, and 150 and 300 g/kg, respectively, instead of maize starch. Each diet was tested using 6 replicate groups of 10 birds each. The regression approach was applied to calculate the pc AA digestibility of the test ingredients.

3. The reduction of the grid size from 3 to 2 mm reduced the average particle size of both maize and soybean meal, mainly by reducing the proportion of coarse particles. Reducing the grid size significantly (P < 0.050) increased the pc digestibility of all AA in the soybean meal. In maize, reducing the grid size decreased the pc digestibility of all AA numerically, but not significantly (P > 0.050). The mean numerical differences in pc AA digestibility between the grid sizes were 0.045 and 0.055 in maize and soybean meal, respectively.

4. Future studies investigating the pc AA digestibility should specify the particle size distribution and should investigate the test ingredients ground similarly for practical applications.