Performance of laying pullets fed on cereal-free diets based on maize offal, cassava peel and reject cashew nut meal.

1. A 70-d experiment was conducted to determine the response of 26-week-old laying pullets to cereal-free diets based on maize offal, cassava peel and full-fat cashew nut meal (CNM) in comparison with a standard 550 g maize/kg reference diet. The 4 test diets all contained 315 g CNM/kg 232.5, 155.0, 77.5 and 0.0 g/kg of maize offal in combination with 77.5, 155.0, 232.5 and 315.0 g/kg of cassava peel, respectively. 2. Pullets fed on the 4 CNM-based diets consumed (P<0.05) less food than those fed on the reference diet; they also had lower (P<0.05) rates of lay, produced less (P<0.05) egg mass, had lower (P<0.05) food conversion efficiencies and their eggs had a lighter (P<0.05) yolk colour. Pullets fed some of the CNM-based diets also gained more (P<0.05) weight, the heaviest (P<0.05) being birds reared on the diet containing 315 g/kg cassava peel. Egg weight, shell thickness and albumen height from all eggs were similar. Pullets fed on the CNM-based diets had inferior (P<0.05) retention of dry matter and protein. 4. It was concluded that feeding full-fat CNM allowed for high dietary inclusion rates of cassava peel and maize offal and the resultant diets, which contained no maize, supported satisfactory performance of laying hens.     

The effect of changing the excreta moisture of caged laying hens on the excreta and microbial contamination of their egg shells

1. An experiment that included 1440 caged laying hens in 24 experimental units was conducted to determine the effect of differences in excreta moisture on the proportion of dirty eggs and the microbial contamination of eggs that were ostensibly uncontaminated by excreta. Excreta moisture contents were changed by giving the hens diets that contained 4 different concentrations of sodium. 2. Diets containing 1.6, 5, 10 or 15 g/kg dietary sodium were fed ad libitum to 1140 laying hens for a 12-week feeding period. A sample of excreta was collected from each experimental unit each week and its moisture content determined. All eggs produced were classified as clean or dirty according to the European Community Egg Marketing Regulations. A sample of eggs were collected from each experimental unit on 4 separate occasions in the last 4 weeks of the feeding period and the total bacterial numbers on ostensibly clean egg shells were determined. 3. Increasing dietary sodium concentration gave linear (P<0.01) increases in excreta moisture. Each 100 g/kg increase in excreta moisture increased (P<0.001) dirty egg numbers by 0.52% of the total eggs produced. Increasing excreta moisture gave a linear increase (P<0.001) in the (log-transformed) numbers of microorganisms that contaminated ostensibly clean egg shells.     

不同饲养方式对蛋鸡生产性能、鸡蛋品质及经济效益的影响

文章旨在评估不同饲养方式对蛋鸡生产性能、蛋品质和血清生化指标的影响。试验选择产蛋性能接近的22周龄海兰褐壳蛋鸡540只,随机分为3组,每组5个重复,每个重复36只。笼养组蛋鸡采用三层阶梯饲养（0.6 m2/只）,网上平养组蛋鸡在金属网丝上饲养（1.5 m2/只）,垫料平养组在平铺20 cm稻壳的水泥地板上平养（1.8 m2/只）。试验共开展28周,包括2周的适应期。结果：网上平养和垫料平养组24～36 w和24～29 w蛋鸡平均日采食量较笼养组蛋鸡分别显著提高5.71%、6.22%和4.81%、4.48%（P＜0.05）。此外,垫料平养组24～36 w和24～49 w蛋鸡的料重比较笼养组分别显著提高7.31%和4.09%（P＜0.05）。在36 w时,垫料平养组鸡蛋的蛋壳强度最高,脏蛋率最低（P＜0.05）。在49 w时,笼养组鸡蛋的蛋壳厚度最低（P＜0.05）,脏蛋率最高（P＜0.05）。笼养组蛋鸡血清葡萄糖、甘油三酯、总蛋白和胆固醇浓度均最高（P＜0.05）,但高密度脂蛋白浓度最低（P＜0.05）。结论：网上平养和垫料平养可以提高蛋鸡采食量,但笼养蛋鸡的饲料效率表现最佳。此外,垫料平养提高了鸡蛋的蛋壳强度和蛋壳厚度,降低了破蛋率。     

Is it possible to increase the n-3 fatty acid content of eggs without affecting their technological and/or sensorial quality and the laying performance of hens?

1. The aim of this study was to increase the n-3 fatty acid (n-3 FA) content of eggs without affecting their sensorial and/or technological properties or the laying performance of hens. Laying hens from line 477 were divided into 5 groups corresponding to 5 different diets over the laying period: control diet (C) and diets containing extruded linseed with a high level of fibre (ELHF), extruded linseed with a low level of fibre (ELLF), microalgae, or a combination of 75% ELLF and 25% MA (ELLF+MA).

2. Dietary enrichment with n-3 FA had no effect on the laying performance, hen body weight or egg white viscosity. The egg yolks produced by hens fed the diet containing microalgae were redder than egg yolks from the other groups, suggesting the presence of red pigments in the microalgae preparation. However, the colour difference was low and not perceptible to the human eye. Moreover, colour measurement of egg yolks by sensorial analysis panellists using the Roche colour fan did not reveal a diet effect on this parameter.

3. Egg yolk lipid content was not affected by diet. The egg yolk of hens fed on diets containing linseed and/or microalgae had greater n-3 FA content (×2.5 to 2.9 compared to group C). Linseed mainly increased the linolenic acid content (×3.0 to 3.4 compared to group C) and the microalgae increased the LC n-3 FA content (×4.1 compared to group C). Dietary enrichment with n-3 FA had no effect on the sensorial quality of shell cooked eggs except for the “unusual flavour” criterion for which the score was higher for the MA group compared to the other groups and corresponded to a fishy flavour.

     

微生态制剂对产蛋后期蛋鸡生产性能及饲料营养物质消化率的影响

本试验选用864只健康海兰褐蛋鸡,随机分为4个处理,在基础日粮中分别添加0.01%、0.02%芽孢杆菌微生态制剂以及0.02%合生素类复合微生态制剂,研究其对蛋鸡生产性能和饲料营养物质消化率的影响。结果表明:0.01%芽孢杆菌组和0.02%复合组极显著提高蛋鸡的产蛋率、产蛋量和采食量(P<0.01),显著提高日粮表观代谢能、干物质及相关氨基酸(除天冬氨酸和酪氨酸外)的表观消化率(P<0.05);0.02%复合组还显著提高蛋鸡平均蛋重(P<0.05),降低料蛋比(P<0.05),提高日粮蛋白质、钙、磷的表观消化率(P<0.05)。添加适量的芽孢杆菌及合生素类复合微生态制剂可以提高产蛋后期蛋鸡生产性能和饲料营养物质表观消化率,但过量使用可能会产生不利影响。     

Effect of feeding clinoptilolite (zeolite) to three strains of laying hens

1. One hundred and twenty 16-week-old, single combed pullets of three strains were fed on a diet containing 160 g protein/kg with or without 50 g clinoptilolite/kg in a trial with 20 hens per treatment. Sterile river sand replaced clinoptilolite in the control diet in order to keep the diets isonergetic. 2. The hens were individually caged in a naturally-ventilated laying house and fed on one of the two diets for ten 28-d periods. 3. No significant dietary effects between treatments were observed with respect to body weight, age at first egg, egg weight, Haugh scores or food intake/hen. 4. Significant dietary effects in favour of clinoptilolite feeding were noticed with the number of eggs laid per hen, shell thickness, efficiency of food utilisation, droppings moisture content and mortality. 5. Significant differences between strains were observed with respect to all measurements taken except food intake/hen d.     

Effects of main cereal type and feed form on production performance,egg quality and egg sanitary indices of laying hens

ABSTRACT

1. The experiment was conducted to evaluate the effects of cereal types (maize or wheat) and feed forms (pelleted or mash feed) on production performance, egg quality and egg sanitary indices in laying hens.

2. Three hundred and sixty hens (Jinghong No. 1) at 18 weeks of age were randomly assigned to four treatments with six replicates of 15 hens per replicate according to a 2 × 2 factorial design with two cereal types (maize or wheat) and two feed forms (pelleted or mash feed).

3. Compared with the wheat-based diet, the maize-based diet improved (P < 0.05) average egg weight of laying hens. Yolk colour of hens fed with the maize-based diet was higher (P < 0.05) in comparison to those fed the wheat-based diet, while Haugh units were lower (P < 0.05) for the maize-based treatment. Egg mass and average daily feed intake of hens fed the pelleted diet were higher (P < 0.05) than of those fed the mash diet. However, the mash diet improved (P < 0.05) yolk colour compared with the pelleted diet. The percentage of dirty eggs for the wheat-based diet was higher (P < 0.05) than for the maize-based diet. The percentage of dirty eggs was higher (P < 0.05) in birds fed the pelleted diet compared with those fed the mash diet. There were interactions (P < 0.05) between cereal type and feed form, with regard to average egg weight and shell thickness.

4. In conclusion, dietary cereal type affected average egg weight, yolk colour and Haugh units in eggs, while feed form influenced egg mass, average daily feed intake and yolk colour.     

氧化鱼油对蛋鸡生产性能、蛋品质及血清抗氧化指标的影响

本试验旨在研究饲粮添加氧化鱼油对蛋鸡生产性能、蛋品质及血清抗氧化指标的影响。选择720只体重相近的38周龄海兰灰蛋鸡,随机分为4个组,每组6个重复,每个重复30只鸡。将新鲜鱼油和过氧化物值(POV)为1 200.10 meq O2/kg的氧化鱼油按不同比例分别加入基础饲粮中,组成新鲜鱼油组(FFO组)、0.25%氧化鱼油组(OFO1组)、0.50%氧化鱼油组(OFO2组)和1.00%氧化鱼油组(OFO3组)。试验期4周。结果表明,试验期内各氧化鱼油组显著降低了蛋鸡的平均蛋重(P<0.05),与FFO组相比,OFO1、OFO2和OFO3组平均蛋重分别降低了0.9%、0.9%和1.7%(P<0.05);氧化鱼油组显著降低了鸡蛋蛋黄颜色和哈氏单位(P<0.05),对蛋壳颜色影响差异不显著(P>0.05);与FFO组相比,OFO3组显著降低了蛋鸡血清谷胱甘肽过氧化物酶活性(P<0.05),显著提高了血清丙二醛含量(P<0.05)。由此可见,蛋鸡饲粮中鱼油被氧化在一定程度上影响了蛋鸡生产性能、蛋品质和血清抗氧化指标。     

Sand intake by laying hens and its effect on egg production parameters

Soil intake may be the most prominent source of environmental contaminants for free range and organic hens, but there are no quantitative data concerning soil intake by domestic hens. Consumption of soil of 14–32 g a day can be estimated from literature, but such a dilution of nutrient intake seems incompatible with high productivity. In this study laying hens were fed pelleted diets with 0%, 10%, 20%, 25% and 30% of sand addition to determine its effect on productivity. Feed intake, feed and nutrient (feed minus sand) conversion ratio, egg production, egg weight and body weight gain were measured over a 4-week period. Acid insoluble ash concentration in the faeces was measured to determine the accuracy of estimating the soil ingestion by the soil-ingestion equation for wildlife as a way to determine soil ingestion of free range and organic hens under practical circumstances. The hens were able to compensate the dilution of the diet with 20%, 25% and 30% of sand by increasing their feed intake. Feed intake increased significantly and feed to egg conversion ratio decreased significantly with increasing sand levels in the diet. The nutrient to egg conversion ratio of the diet without sand tended to be worse than for the diets with sand, presumably due to the total absence of coarse material in the diet. There were no differences in egg production and egg weight between hens fed the different diets but body weight gain was significantly lower for the hens fed the diets with 20%, 25% and 30% of sand. Estimation of sand ingestion was done by the soil-ingestion equation for wildlife. Provided that the actual dry matter digestibility coefficient of the nutrient part of the diet is taken into account, estimating the soil ingestion according to the soil-ingestion equation for wildlife seems an appropriate way to determine soil ingestion for free range and organic hens under practical circumstances.     

Dietary soluble non-starch polysaccharide level and xylanase supplementation influence performance,egg quality and nutrient utilization in laying hens fed wheat-based diets

The aim of this study was to evaluate the effects of dietary soluble non-starch polysaccharide (sNSP) content and xylanase supplementation on production performance, egg quality parameters, and nutrient digestibility in Hy-line Brown layers from 25 to 32 wk of age. A total of 144 Hy-line Brown laying hens (25 wk of age) were randomly allocated to 1 of 4 wheat-based dietary treatments in a 2 × 2 factorial experimental design, with 36 replicates of individual hens per treatment. The diets were formulated to contain either a high or low sNSP level (at 13.3 or 10.8 g/kg) and were supplemented with either 0 or 12,000 BXU/kg exogenous xylanase. Birds were fed these treatment diets for an 8-wk period, and hen production performance, including daily egg production, average egg weight, daily egg mass, feed conversion ratio and proportion of dirty and abnormal eggs were measured at bird age 25 to 28 wk and 29 to 32 wk. An interaction between sNSP content of the diet and xylanase supplementation was observed on daily egg production from 25 to 28 wk of age (P = 0.018); birds fed the high sNSP diet without xylanase had lower egg production than those fed any other treatment. An interaction between the 2 dietary factors was also observed on hen weight gain at 29 to 32 wk of age (P = 0.014), with birds fed the low sNSP diet with 12,000 BXU/kg xylanase presenting greater weight gain compared to those fed the high sNSP diet with 12,000 BXU/kg xylanase. Feed intake at 29 to 32 wk of age was reduced by xylanase supplementation (P = 0.047). Xylanase supplementation also increased yolk colour score at both 28 and 32 wk of age, and decreased yolk weight at 32 wk of age (P = 0.014, 0.037 and 0.013, respectively). Birds fed the low sNSP diet presented lower protein digestibility (P = 0.024) than those fed the high sNSP diet. Additionally, birds fed high sNSP presented higher shell reflectivity at both 28 and 32 wk of age (P = 0.05 and 0.036, respectively). The influence of duration of feeding the treatment diets on egg quality was also determined. It was observed that egg weight, yolk weight and yolk colour score consistently increased over time, regardless of experimental treatment effects. In contrast, Haugh Unit and albumen height significantly decreased throughout the study period in all treatments, although this was less pronounced in hens fed the treatment with high sNSP and no supplemental xylanase. A reduction in shell breaking strength over time was observed only in hens fed the treatments without xylanase addition, and shell thickness was improved over time only in birds fed the low sNSP diet with xylanase. The impacts of the dietary treatments were largely inconsistent in this study, so a solid conclusion cannot be drawn. However, these findings do indicate that dietary NSP level influences layer production performance, and thus should be considered when formulating laying hen diets. It also proved that further research is warranted into how to optimize the benefits of xylanase application in laying hens.     

Effects of dietary borate and aluminate on riboflavin metabolism in the breeding hen

Breeding hens were used to investigate the effects of aluminate and borate ingestion on riboflavin metabolism. Groups of six hens were fed on either a control diet, or the control diet plus 15 g kg-1 of either sodium metaborate or sodium meta-aluminate. All diets contained 6 mg kg-1 riboflavin. Daily egg production per hen in the borate group had mean values of 0.71, 0.21 and 0.02 for the three weeks of the study. The values were 0.91, 0.91, 0.86 and 0.86, 0.74, 0.89 for the control and aluminate groups, respectively. Fertility (fertile eggs per 100 set) and hatchability (live chicks per 100 fertile eggs) were both nil in the borate-treated hens, compared with 57 and 95 and 59 and 100 for the control and aluminate-treated hens, respectively. Fluorimetric analysis of blood plasma, egg yolk and albumen showed that the riboflavin contents of all tissues were greatly reduced in the borate-treated hens. Borate ingestion can therefore induce a severe riboflavin deficiency in the hen, but aluminium, a more universal contaminant of food or water, did not impair riboflavin metabolism when fed as aluminate.     

Replacing maize with pearl millet in laying hens’ diets

Pearl millet grain could be considered as an alternative feed ingredient for poultry. In a 12 wks experiment, the performance of laying hens fed diets containing pearl millet were compared with those fed diets containing corn. Maize grain was replaced by pearl millet on an equal-weight at either 0, 25, 50, 75 or 100%. Results showed that use of 25, 50 and 75% of pearl millet in place of maize in the diet resulted in similar (P > 0.05) hen-day egg production, egg mass, egg weight, feed intake and feed conversion ratio to those of control group. Totally replacement of maize grain with pearl millet significantly (P < 0.05) reduced all production parameters. Egg quality parameters did not affect by using pearl millet in the diet. These results showed that maize grain can be replaced by pearl millet up to 75% in the diets of laying hens without any adverse effect on hen performance or egg quality.     

The effects on egg production and egg composition of adding supplements of amino acids and/or urea or dried auto‐claved poultry manure to a low‐protein layer diet

Thirty‐five laying hens of a medium‐weight hybrid strain, aged 10 months, were given a basal diet containing 11.5% protein or the same diet supplemented with 1.54% essential amino acids and/or with two sources of nitrogen for the synthesis of non‐essential amino acids (1.15% urea or 9.7% dried autoclaved poultry manure) for an 8‐week period.

Egg production, food intake, food conversion efficiency, the gross efficiency of nitrogen conversion and the ability of hens to maintain body weight were improved by supplementation with essential amino acids (P < 0.05 or P < 0.01). Supplementation with dried autoclaved poultry manure raised food intake, total egg mass and mean egg weight (P < 0.05), but supplementation with urea alone did not result in significantly higher egg production, perhaps because it failed to increase food intake. Supplementation with essential amino acids and urea to give the equivalent of 16% protein did not result in significantly higher egg production than that obtained with urea alone. The smallest eggs were produced by hens fed on the diet supplemented with urea, and the largest by those fed on the diet supplemented with dried manure (P < 0.001).

The gross composition of eggs was not influenced significantly by dietary treatment but albumen quality was significantly lower on the basal diet and higher on the supplemented diets (P < 0.001). It was highest in eggs from hens fed on the diet supplemented with urea alone.     

Dietary levels of chia: influence on hen weight,egg production and sensory quality,for two strains of hens

1. Laying hens, 225 white and 225 brown, were fed for 90 d to compare a control diet with diets containing 70, 140, 210 and 280 g/kg chia (Salvia hispanica L.) seed. 2. Hen weight was not significantly affected by diet; however, manure production was less for the hens fed on chia. 3. Egg weight and production, yolk weight, and yolk percentage were determined at d 0, 30, 43, 58, 72 and 90. 4. A sensory evaluation was conducted on eggs produced during the last week of the trial. 5. No significant differences in egg production were found among treatments for the brown hens. 6. With the 280 g/kg chia diet, the white hens produced fewer and lighter eggs than did the hens fed on the control diet. 7. No significant differences were detected in yolk weight until d 90. 8. On this date the yolks produced by the white hens fed on the 70 g/kg chia diet were significantly lighter in weight, whereas the brown hens produced significantly heavier yolks, compared with the hens fed on the control diet. 9. Yolk weight as a percentage of egg weight was lower for white hens throughout the trial except on d 58 with the 140 g/kg chia diet. Significant differences, however, were detected only with the 70 g/ kg chia diet on d 90 and with the 210 g/kg chia diet on d 58, 72 and 90. 10. No significant differences in taste preference or flavour were found among any of the chia treatments and the control.     

Impacts of dried whole eggs on productive performance, quality of fresh and stored eggs, reproductive organs and lipid metabolism of laying hens

1. Rejected eggs were processed by freezing, freezing and boiling, or autoclaving, dried at 55°C, and the chemical and amino-acid analysis and microbiological properties of the dried whole eggs (DWE) determined. The processed DWE was included in a laying-hen mash diet at 50 or 100 g/kg, mainly to replace soybean meal and maize, in a factorial design of 3×2 and fed to hens between 25 and 41 weeks of age. In addition, a control diet without DWE was used to create a total of 7 treatments; each having 5 replicates of 5 hens. 2. Hens fed the diet containing 50-g/kg frozen and boiled DWE and 100-g/kg frozen DWE laid the largest egg size, while hens fed the 50-g/kg frozen and boiled or autoclaved DWE diets yielded the highest egg mass and best feed conversion efficiency. 3. Hens fed the 50-g/kg frozen DWE laid eggs with a higher yolk indices, Haugh unit scores, and eggshell thickness and maintained higher Haugh unit scores during egg storage. 4. Yolk cholesterol significantly decreased in eggs from groups fed either the 50-g/kg frozen or autoclaved DWE diet, with freezing having the stronger effect. 6. In conclusion, 50-g/kg autoclaved DWE diets fed to laying hens between 25 and 41 weeks of age had no adverse effects on production, egg quality or reproductive organs, but decreased yolk cholesterol, and thus could be beneficially included in laying-hen diets.     

葡萄糖氧化酶对蛋鸡日粮主要营养物质表观消化率及肠道微生物的调控作用

本研究旨在探讨葡萄糖氧化酶(glucose oxidase,GOD)对蛋鸡日粮营养物质表观消化率和肠道微生物的影响.采用单因子随机区组试验设计,将180只26周龄海兰褐蛋鸡随机分为5组,研究日粮中添加葡萄糖氧化酶对营养物质消化率以及盲肠微生物数量的影响.结果表明,日粮中添加0.1%、0.2%、0.3%和0.4%的葡萄糖氧化酶,试验组日粮粗蛋白质表观消化率分别提高15.25%(P<0.05)、28.40%(P<0.01)、23.32%(P<0.01)和26.10%(P<0.01);钙表观消化率分别提高3.37%(P>0.05)、4.71%(P>0.05)、8.01%(P<0.01)和7.30%(P<0.05);总磷的表观消化率分别提高17.74%(P>0.05)、16.30%(P>0.05)、24.58%(P<0.01)和27.32%(P<0.01).蛋鸡日粮中添加0.2%～0.4%葡萄糖氧化酶可显著提高盲肠内容物中乳酸杆菌数量,降低大肠杆菌数量.由此可知,葡萄糖氧化酶可调控肠道内微生态平衡,维护鸡的肠道健康,促进日粮营养物质的利用.     

液体蛋氨酸羟基类似物对蛋鸡生产性能、鸡蛋品质、养分利用率和血液生化指标的影响

试验用38周龄健康的罗曼粉壳蛋鸡600只,经饲喂玉米-豆粕-麦麸型基础日粮(蛋氨酸0.22%、蛋氨酸+胱氨酸0.48%)10d后,随机分为4个处理,每个处理5个重复,每个重复30只蛋鸡。处理1为对照组,饲喂基础日粮;处理2在每千克基础日粮中添加1.325gDL-Met;处理3和处理4以液体蛋氨酸羟基类似物(HMB,活性物质88%)在等摩尔基础上按100%或50%分别替代处理2的DL-Met。试验期10周。试验结果表明:在基础饲粮中添加DL-Met以满足高产蛋鸡的蛋氨酸需要可提高3～10周的产蛋率,并极显著地提高了3～10周的蛋重、日产蛋重、干物质、钙、磷和粗蛋白的表观代谢率(P<0.01),极显著降低了饲料转化率比(P<0.01),对采食量、鸡蛋蛋形指数、破蛋率、软蛋率、蛋黄重、蛋黄比例、哈氏单位、蛋壳重、蛋壳厚度、蛋壳强度、鸡蛋水分和粗蛋白含量无显著影响(P>0.05)。在等摩尔基础上HMB以100%或50%替代DL-Met,对蛋鸡生产性能、鸡蛋品质和养分代谢率的影响与DL-Met无显著差异。结果表明在蛋鸡玉米-豆粕-麦麸型饲粮中HMB的生物学效价与DL-Met相同。     

Effect of feeding clinoptilolite (zeolite) on the performance of three strains of laying hens

1. One hundred and twenty 16‐week‐old single combed pullets of three strains were fed on a diet containing 135 g protein/kg with or without 50 g clinoptilolite/kg in a trial with 20 hens per treatment. Sterile river sand replaced clinoptilolite in the control diet in order to keep the diets isoenergetic. The hens were individually caged in a naturally ventilated laying house and fed one of the two diets for ten 28‐d periods.

2. Significant dietary effects of feeding clinoptilolite were observed with number of eggs laid per hen, shell thickness, efficiency of food utilisation and droppings moisture content. No significant dietary effects between treatments were observed with body weight, age at first egg, egg weight, Haugh units, food intake/hen and rate of amino acid absorption of radioactive lysine and methionine into the bloodstream. Significant differences between strains were observed with regard to all parameters except food intake/hen. There were no significant strain × clinoptilolite interactions.     

Evaluation of pearl millet and flaxseed effects on egg production and n-3 fatty acid content

1. A 6-week trial was conducted to evaluate the effects of pearl millet (PM) as a replacement for maize, in combination with flaxseed (FS), on productivity, egg trait parameters and egg n-3 fatty acid (FA) content in White Leghorn hens. 2. Six diet treatments were used: a control (CTL, maize-soybean meal based) diet, and diets containing 0, 2, 4, 8 or 12% FS, in which all maize was replaced by PM (PM-0, PM-2, PM-4, PM-8 and PM-12, respectively). All diets were isocaloric and isonitrogenous and met NRC (1994) requirements. Eight cage replicates per treatment were used (three hens per cage). At the end of each week, three eggs were randomly collected from each cage to measure egg trait parameters and yolks were separated, pooled and lyophilised for FA determination. Body weights and feed consumption were recorded weekly. Egg production (number of eggs and egg mass produced) was recorded daily. At the end of the experiment, all hens were killed to determine liver haemorrhage score. 3. Egg traits and flock performance parameters were not different among treatments except at week 4, when birds on the PM-12 diet produced smaller eggs than hens on the PM-0 and PM-2 diets. Yolk pigmentation scores were lower for the PM-0 and PM-2 diets (1.60 +/- 0.24 and 1.80 +/- 0.20, respectively), increased with higher inclusions of FS (2.75 +/- 0.47 for PM-12 diet) but did not reach control levels (6.00 +/- 0.01). Liver haemorrhage scores were not affected by dietary treatment. Hens given the PM-8 and PM-12 diets produced eggs with n-3 FA content higher than required to be considered as n-3 FA enriched eggs, and had a lower n-6/n-3 FA acid ratio than eggs of hens consuming CTL or the PM based diets with lower FS supplementation. 4. These results suggest that PM can be used to substitute for maize in the diets of layers and may reduce the amount of FS needed to obtain n-3 FA enriched eggs.     

日粮添加甜菜碱对夏季高温蛋鸡生产性能、蛋品质及血液理化特征的影响

本研究旨在评估夏季高温时日粮添加甜菜碱对蛋鸡生产性能、蛋品质及骨骼和血液理化特性的影响.试验将480只产蛋性能一致的罗曼粉壳蛋鸡随机分为2组,每组240只,每组10个重复(24只/重复).对照组饲喂基础试验日粮,处理组蛋鸡饲喂基础试验日粮+150?mg/kg甜菜碱,试验为期8周.结果:日粮添加150?mg/kg甜菜碱对...