Relationships between digestibilities of food components and characteristics of wheats (Triticum aestivum) introduced as the only cereal source in a broiler chicken diet

1. The aim of the experiment was to establish relationships between chemical or physical characteristics of wheats (Triticum aestivum) and digestibilities of food components in broiler chickens fed on wheat-based diets. Twenty-two wheat samples, each differing by their cultivar origin, were included at 550 g/kg in diets offered to male Ross broiler chicks. The other main ingredients were soya bean meal (340 g/kg) and rapeseed oil (68.5 g/kg). Diets were given as pellets. 2. In vitro viscosities of wheats measured as potential applied viscosity (PAV) or real applied viscosity (RAV) varied between 1.91 and 6.03, or between 0.95 and 3.81 ml/g (dry matter basis), respectively. Hardness of wheats varied between 17 (soft) and 95 (very hard), and lipase activity of wheats varied from 1 to 13.6 (relative scale). 3. PAV and RAV values were not significantly correlated with hardness. PAV and RAV values were correlated with (80:20) ethanol:water insoluble, water soluble arabinoxylans (r = 0.961, 0.932, respectively), with the amount of water retained by cell walls (r = 0.656, 0.492, respectively), and with lipase activity (r = 0.600, 0.532, respectively. 4. Hardness was correlated with ash (r = -0.484), nitrogen (r = 0.534), mean particle size of wheat flours (r = 0.631), and specific energy of pelleting (r = -0.574). 5. Wheat diets were evaluated in two assays with 3-week-old chicks, with 11 diets per assay. In each assay, a balance experiment was carried out using the total collection method. Growth performance was also measured during the balance experiment. 6. In vitro viscosity parameters were negatively correlated with diet AMEn (P < 0.05), lipid digestibility (P < 0.05) and, to a lesser extent, protein digestibility (P < 0.05). In vitro viscosity data were positively correlated with food:gain ratio (P < 0.05) and water loss parameters (P < 0.05), and were not significantly (P > 0.05) correlated with starch digestibility. 7. Wheat hardness-related parameters were correlated (P < 0.01) with individual starch digestibility (hardness, proportion of coarse particles in wheat flour, specific energy of pelleting: r = -0.273, -0.305, 0.212, respectively). 8. Wheat lipase activity was negatively correlated with individual lipid (r = -0.179; P < 0.05) and starch (r = -0.225; P < 0.01) digestibilities and with individual diet AMEn (r = -0.266; P < 0.001). Individual diet AMEn values were correlated (r = 0.175) with the values calculated by the EU AMEn prediction equation (Fisher and McNab, 1987). Among the correlations observed between the individual measured AMEn:EU predicted AMEn ratio and wheat parameters (P < 0.05), the correlation obtained with wheat lipase was the highest (r = -0.195). The correlations with lipase could be explained in part by strong correlations between lipase and in vitro viscosity parameters.     

Polymelia in a broiler chicken

A polymelus monster was observed in a 7-week-old slaughterhouse chicken. The supernumerary limbs were smaller than the normal appendages but contained an equal number of digits.     

Skeletal response to diet with soya bean seeds used as primary source of protein in growing broiler chickens

The study was conducted using 120 commercial broiler chicks (Ross 308) randomly allocated to two experimental groups. The experimental diets, differing only in protein source, either solvent‐extracted soya bean meal (SBM) or traditional (non‐genetically modified) full‐fat soya bean seeds (FFS), were prepared using practical corn‐based formulation designed to meet nutritional requirements of broilers. Performance parameters were monitored weekly. Also, the subjects were evaluated daily for overt changes in skeletal anatomy and gait physiology. Randomly selected chickens from each group (seven males and seven females) were euthanized at 2, 3, 4 and 6 weeks of age, and bone specimens were collected for further study. Bone mineral density (BMD) and bone mineral content (BMC) were determined in tibiotarsal bones. Broilers fed FFS diet showed retarded growth rate and decreased feed intake (both p < 0.001). Both BMD and BMC parameters were significantly lower (p < 0.05) in bones of chickens from the FFS group in comparison with the SBM group. The chickens fed the FFS diet showed higher incidence of skeletal pathology including angular deformities and torticollis (both p < 0.01). Of note, cases of torticollis were observed only in FFS group. In many cases, skeletal abnormalities resulted in considerable changes in gait pattern, and in some instances, the pathology of leg bones was so advanced that the affected individuals were unable to walk, but this deformity was not seen in SBM group. From this study, it can be inferred that raw soya beans contain factors that have some specific detrimental effects on skeletal system of chickens.     

Apparent metabolisable energy and amino acid digestibility of microalgae Spirulina platensis as an ingredient in broiler chicken diets

ABSTRACT

1. This work investigates the apparent metabolisable energy (AME), its nitrogen-corrected form (AMEn) and amino acid (AA) digestibility coefficients of the microalgae Spirulina platensis as an ingredient in broiler chicken diets.

2. One group of birds was fed with a basal control diet (BD), and another was fed with a test diet composed of the BD with the addition of the microalgae at a proportion of 200 g/kg. AME and AMEn were assessed by total excreta collection and indigestibility analysis using acid-insoluble ash (AIA) as a marker.

3. The microalgae comprised 888.0 g/kg dry matter (DM), 18.42 MJ/kg gross energy, 514.7 g/kg crude protein, 9.9 g/kg ether extract, 10.6 g/kg crude fibre, 94.4 g/kg ash, 3.1 g/kg Ca and 11.0 g/kg P.

4. The values obtained for AME (13.48 MJ/kg DM) and AMEn (11.72 MJ/kg DM) were higher (p < 0.01) than those obtained using the AIA method (9.39–8.29 MJ/kg DM). The microalgae ileal digestibility coefficients were 0.80 ± 0.04 and 0.78 ± 0.04 for essential and non-essential AA, respectively.

5. Overall, the metabolisable energy content and digestibility of AA for S. platensis indicated that the microalgae are potentially an alternative nutrient source for broilers. The AIA method underestimated AME and AMEn in comparison to the total excreta collection method.     

肉鸡饲粮能量水平对植酸酶作用效果的影响

试验选用324只1日龄AA肉鸡(公鸡),采用3×2因子设计,研究在不同能量水平的饲粮中添加植酸酶对肉鸡生长性能和养分利用率的影响。试验设3个能量水平(12.33、12.13、12.03MJ/kg)和2个酶水平(0、500FTU/kg),共计6个处理组,每个处理组6个重复,每个重复9只鸡,试验期42d。结果表明:饲粮添加植酸酶显著(P<0.05)或极显著(P<0.01)提高了肉鸡日增重、采食量,改善了饲料利用率,提高了干物质、粗蛋白、钙、磷的利用率,但对能量利用率没有明显影响(P>0.05);降低饲粮能量水平极显著降低了肉鸡对干物质、能量、钙的利用率(P<0.01),显著降低了其对磷的利用率(P<0.05),但对生产性能和粗蛋白利用率没有显著影响(P>0.05);植酸酶和能量对肉鸡饲料利用率、干物质和钙的利用率存在显著的交互作用(P<0.05),表现为处理2组能量水平条件下添加植酸酶在生长性能和养分利用率上改善幅度最大,表明植酸酶在适宜降低能量水平的饲粮中的作用效果更好。试验中,以能量水平为12.13MJ/kg的肉公鸡饲粮中添加500FTU/kg植酸酶(处理5组)为最佳组合。     

Myxoid leiomyosarcoma of the gizzard in a broiler chicken

A leiomyosarcoma was found in the gizzard of a 57-day-old female broiler chicken weighing 1.8 kg. Grossly, the tumor mass, 13.0 x 8.5 x 10.0 cm, enveloped the gizzard and had a gelatinous appearance due to the rich production of mucin. Miliary metastatic tumors were noted in the liver. Histopathologically, there was marked production of mucus throughout the tumor tissue, and densely or loosely arranged long spindle-shaped leiomyosarcoma cells proliferated. The tumor cells had a low rate of mitosis, showed slight cellular atypia, and, immunohistochemically, were positive for actin, alpha-smooth muscle actin, and desmin. Electron microscopically, various amounts of microfibrils with focal densities, dense patches, and basal plates were observed.     

Sunflower seed meal as a substitute for soybean meal in commercial broiler chicken diets

1. An experiment was conducted to study the possibility of replacing soybean meal (SBM) with sunflower seed meal (SFM) in broiler chick diets. The SBM in broiler starter (317.9 g/kg) and finisher (275.4 g/kg) diets was replaced with SFM at 33, 67 and 100% on an iso-caloric and iso-nitrogenous basis using sunflower oil to balance the energy content of the diets. The metabolisable energy levels used in the diet were considerably less than the recommended levels for broilers. Each experimental diet was fed ad libitum from 2 to 42 d of age to 8 replicates of 5 birds. Parameters studied included amino acid and apparent metabolisable energy contents in food ingredients, body weight, food intake, food efficiency, leg abnormality score, dry matter digestibility, carcase traits, relative weight and length of intestine, fat and protein content in liver and serum biochemical profile. 2. SFM had higher concentrations of calcium, phosphorus, methionine and cystine and lower energy content than SBM. 3. Replacement of SBM with SFM up to 67% in starter and 100% in finisher diets did not affect weight gain. Total and 67% replacement of SBM with SFM depressed food efficiency at 21 and 42 d of age, respectively. Food intake was significantly higher in SFM-based diets than in the SBM reference diet at 21 and 42 d of age, except in groups given SFM100 at 21 d of age. In the latter group, the food intake was similar to that on the SBM reference diet. The digestibility of dry matter decreased with increased levels of SFM in the diet. 4. The relative weights of giblet, liver and abdominal fat, length of intestine, activity of alkaline phosphatase, concentrations of calcium and inorganic phosphorus in serum were not influenced by incorporation of SFM in the broiler diet. 5. The ready to cook yield and liver fat content decreased, while the relative weights of gizzard and intestine and protein content in liver increased, with increasing levels of SFM in the diet. 6. The concentration of HDL cholesterol increased while the concentration of LDL cholesterol decreased with increasing content of SFM (> or =67% of SBM) in diet. The serum protein concentration decreased progressively with increase in dietary SFM. The concentrations of protein and triglycerides in serum were lowest in groups receiving SFM100. 7. Body weight gain was not affected by total replacement of SBM with SFM at 42 d of age. However, considering food efficiency, carcase yields, serum lipid profile and level of supplemental fat in diet, it is concluded that SFM can replace up to two-thirds of soybean, corresponding to inclusion of 345 and 296 g SFM per kg for starter and finisher phases, respectively.     

Pharmacokinetics of sparfloxacin in broiler chicken

1. The pharmacokinetics of sparfloxacin in broiler chicken was investigated following a single intravenous dose of 10 mg/kg and a single oral dose of 20 mg/kg. The pharmacokinetic parameters (AUC(0-24) or C(max)) were integrated with the pharmacodynamic parameter (MIC(90)) to optimize sparfloxacin dosage in chicken. 2. The apparent volume of distribution, total body clearance, mean residence time and elimination half-life following oral administration were 2.411/kg, 4.55 ml/min per kg, 10.54 and 5.94 h, respectively. Oral bioavailability was 61.7%. 3. Sparfloxacin was found to possess clinically useful pharmacokinetic properties. Based on pharmacokinetic/pharmacodynamic integration an oral dose of 20 mg/kg sparfloxacin for every 24 h might be recommended for a successful clinical effect in chickens.     

Pharmacokinetics of ofloxacin in broiler chicken

Pharmacokinetics of ofloxacin, a fluoroquinolone antimicrobial agent, was determined in broiler chickens after intravenous or oral administration of a single dose (10 mg/kg). Ofloxacin concentrations in plasma were determined using a high-performance liquid chromatography assay. Plasma concentration profiles were analyzed by the noncompartmental method. Elimination half-life and mean residence time of ofloxacin in plasma were 4.46 and 5.48 h after intravenous administration and 5.85 and 7.43 h, respectively, after oral administration. Maximal plasma concentration of 3.65 microg/mL was achieved at 1.25 h after oral administration. Apparent volume of distribution of 1.76 and 2.16 L/kg and total body clearance of 4.96 and 4.5 mL/min/kg were obtained following intravenous and oral administration, respectively. The oral bioavailability of ofloxacin was 110.01%. Ofloxacin was found to be more rapidly absorbed, widely distributed and more quickly eliminated than other fluoroquinolones in broilers. Based on these kinetic parameters, a dosage of 10 mg/kg given orally every 24 h can be recommended for the treatment of bacterial infections with MIC90 < 0.3 microg/mL.     

肉仔鸡饮水量——鸡的一个福利指标

本研究目的是分析商业化生产条件下的肉仔鸡饮水量数据以调查:①所获得的结果与其他研究结果之间的相互关系;②饮水量是否可以被客观地用作肉鸡健康和福利的量度标准;③总饮水量与淘汰水平和接触性皮炎的发病率之间是否存在相互关系?饮水量按"L/羽/c"即每羽肉鸡每个饲养周期(cycle)的平均饮水量)和"L/羽/d"即每羽肉鸡每天的平均饮水量)((的方式表示。为了确定饮水量对垫料湿度的影响,用水量也以"L/m2/c"即每个饲养周期每平方米鸡舍地面的平均用(水量(升))和"L/m2/d"即每天每平方米鸡舍地面所消耗的用水量(升)的方式表示,这两个指标考虑了肉鸡的饲养密度。(结果表明,以"L/m2/c"表示的饮水量可能是一个有益的滞后指标(LagIndicator),而以"L/羽/d"或"L/m2/d"表示的饮水量可能是一种先行指标(LeadIndicator),与肉鸡的健康状况以及饮水量对垫料质量的影响有关;同时表明还应进行更多的研究以确定肉鸡实测的每日饮水量与预期的每日饮水量之间的差异是否与其健康状况(如肠炎、接触性皮炎等)有直接的关系。本试验应该规定以"L/m2/d"方式表示的用水量的阈值,即饮水量达到此水平时会对垫料质量产生一个综合影响。该阈值可能受饲养密度、通风条件和垫料原料吸湿程度的影响,但是该值将向管理员提供一个"触发点"当处于该点时他们需采取行动以便将对空气质量(以氨气浓度的方式表示)的综合影响以及接触性皮炎发病的可,能性降至最低程度。     

A comparison of a new net energy system with the metabolisable energy system in broiler diet formulation,performance and profitability 1

Two trials were conducted with unsexed broilers to compare a net energy (NE) system and a metabolisable energy (ME) system on least‐cost broiler diet formulation, broiler performance and economic efficiency. Both energy systems were compared in the range of 3000 (2161) to 3400 kcal ME/kg (2560 kcal NE/kg) using rations with increasing energy concentration of about 100 kcal/kg food.

The two different energetic evaluation systems had considerable effect on dietary composition, the penalty cost of rejected ingredients, the marginal profit of some limiting constraints and the position of the least‐cost nutrient concentration. The starter and finisher rations, based on NE values, were on average 4.77 and 2.43 BF²/100 kg cheaper, respectively than those based on ME values. For equal NE contents, they contained 50 to 70 kcal less ME/kg and 1% less crude protein.

The broiler performances were on average better on the NE‐diets. The mean difference of 20 to 30 g in body weight was significant at 4 and 6 weeks (P < 0.01 and P < 0.05).

Regression analysis indicated no significant effect of rising energy concentration on food intake with the ME‐diets, but a significant (P < 0.05) linear decrease with the NE‐diets of 1.16 ± 0.34 and 1.72 ± 0.37 g/chick d at 6 and 8 weeks respectively for every 100 kcal/kg rise in the NE content of the ration. As a result body weight at 6 weeks improved linearly per increment of 100 kcal NE/kg with 37.2 ± 3.2 g (P < 0.05) on the ME‐diets and with 18.8 ± 6.8 g (P = 0.08) on the NE‐diets.

The efficiency of food utilisation, although slightly better on the NE‐diets, was not significantly affected by the energy systems. As expected, linear improvements (P < 0.001) of respectively 58 ± 6 and 62 ± 11 g food/kg weight gain at 6 and 8 weeks were noted for every increment of 100 kcal NE/kg diet.

Returns over food costs were for the whole energy range higher on the NE‐diets (average 0.66 BF/chick, variation 1.01 to 0.23 BF/chick). Gross profit increased with rising nutrient density from 16.33 to 17.97 BF/chick on the ME‐diets and from 17.34 to 18.23 BF/chick on the NE‐diets. The data illustrate that the economical efficiency of broiler production can be considerably improved by taking into account the effect of both energy content and energy system.     

Reducing growth rate of broiler chickens with a low energy diet does not improve cortical bone quality

1. Reducing growth rate is often supposed to allow better skeletal development and improve bone quality. In order to test this assumption, flocks of broiler chickens fed on a diet containing 13.31 MJ ME/kg (H) were compared with flocks in which the growth rate was reduced by feeding birds with a low energy diet (L, 9.62 MJ ME/kg). 2. Bone growth was studied in 2 experiments in order to identify any changes in bone tissue of slow-growing chickens that might explain why they are less predisposed to varus-valgus deformities (3.1% vs 19.9%). 3. In experiment 1, the morphology, composition and histomorphometry of the tibiotarsi were analysed in both groups at 1, 12, 26, 42 and 46 d of age. Tibial variables (weight, volume, length, cortex size and structure, dry content and ash percentage) were always reduced in slow-growing birds except at 42 d of age, when tibial weight and cortex areas were similar in both groups. 4. Every variable was similar in both groups, or even higher in H birds, when chickens were compared at similar body weight, suggesting that the low growth rate did not improve bone quantity or quality of the tibiae. 5. In experiment 2, the composition of the tibiotarsi was compared every 2 days during the first week and twice a week until 36 d of age, in H and L birds. Weight and composition of the tibiotarsi did not differ between groups when compared at equal body weight, as also shown in experiment 1. 6. The reduced occurrence of varus-valgus deformities in slow-growing chicks cannot be related to an improvement in the structure and the composition of their bone tissue.     

日粮苏氨酸和肉鸡生产

苏氨酸是肉鸡的必需氨基酸之一。随着工业生产的晶体苏氨酸越来越普及,人们对苏氨酸在肉鸡生产中应用的兴趣逐渐增长,这方面的科技文章不断见诸于国内外科技杂志中。现有资料显示,苏氨酸对于肉鸡生产具有重要意义。恰当的     

Nutritive activity of soluble rice bran arabinoxylans in broiler diets

1. A soluble material (703 g/kg non‐starch polysaccharide, 141 g/kg starch and 166 g/kg protein) of low viscosity (termed RB‐NSP), was isolated in large quantities from defatted Australian rice bran using a mild alkaline extraction and ethanol precipitation.

2. The soluble non‐starch polysaccharide fraction of RB‐NSP comprised arabinose (0.40 mol%), xylose (0.32 mol%) galactose (0.17 mol%), glucose (0–08 mol%) and mannose (0.03 mol%).

3. RB‐NSP was included at graded concentrations (0, 20, 40 and 60 g/kg) in a sorghum/casein basal diet and the diet fed to male broilers in a classical balance trial to determine apparent metabolisable energy (AME). The AME values recorded were 13.26, 13.85, 14.26 and 14.00 MJ/kg DM with a significant correlation (r = 0.65, P< 0.001) between dietary RB‐NSP inclusion rate and dietary AME.

4. Feeding RB‐NSP had no effect on growth, food conversion ratio or the digestibilities of starch and protein which were both high (0.98–0.99 and 0.88–0.89, respectively).

5. It was concluded that the RB‐NSP may have been a substrate for hindgut fermentation in the broiler but that it possessed no anti‐nutritive activity.     

Chondroitin sulphate distribution in broiler chicken carcasses

1. The content of chondroitin sulphate (CS), known as a nutraceutical, was estimated in broiler chicken carcasses by analysing sulphated glycosaminoglycan uronic acid in posterior sternum (keel) cartilage and bones from 4 parts (wing, leg, front and hind) of carcasses.

2. The results of the present study suggested that approximately 0.63 g CS uronic acid (or 1.9 g as CS) can be extracted from a 1.66 kg whole broiler chicken carcass. The amount of extractable CS from keel cartilage, which has been reported as a valuable source of CS in broiler chicken carcasses, was surprisingly low (<10% of total CS).     

Trace mineral interactions in broiler chicken diets

1.?The aim of the present study was to demonstrate trace mineral interactions among organic copper, iron, manganese and zinc (Cu, Fe, Mn and Zn) in broiler chickens.

2.?Three experiments were conducted using a control diet which was deficient in Cu, Fe, Mn and Zn.

3.?In experiment 1, the control diet, supplemental organic Cu, Fe alone and combined diets, were randomly fed to 4 groups of one-day-old Cobb broilers (each group had 6 replicates of 4 birds).

4.?In experiment 2, the control diet, supplemental organic Mn and Zn alone or combined with Cu, Fe diets and corresponding inorganic combined diet, were randomly fed to 6 groups (each group had 8 replicates of 6 birds).

5.?In experiment 3, the depletion of organic Zn, the depletion of inorganic Zn and normal Zn treatments were carried out in three groups of one-day-old Cobb broilers (each group had 8 replicates of 6 birds).

6.?Adding organic Cu, Fe and Mn alone or combined to Zn deficient diets did not significantly improve bird performance and were mostly excreted. Supplemental organic Zn alone or combined with other elements significantly increased feed intake, body weight gain and tibia bone length. However, supplemental organic Fe alone or combined with Cu significantly increased feed intake but had no obvious effect on body weight gain. The organic Fe supplementation resulted in a wider tibia.

7.?Depletion of organic and inorganic Zn resulted in decreased feed intake, body weight gain and total tibia bone Zn content. Zinc deficiency did not affect the uptake of organic Fe by tibia bone but reduced its total Fe content.

8.?Zinc is the first limiting element among these 4 trace minerals. Adding Mn, Cu and Fe to Zn deficient diets did not stimulate bird performance. Surplus organic Fe and Cu resulted in increased feed intake and increased tibia bone Fe content but did not contribute to bird performance.