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1.
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.  相似文献   

2.
A 24-week performance trial was conducted to evaluate the efficacy of an experimental phytase on performance, egg quality, tibia ash content and phosphorus excretion in laying hens fed on either a maize- or a barley-based diet. At the end of the trial, an ileal absorption assay was conducted in order to determine the influence of phytase supplementation on the apparent absorption of calcium and total phosphorus (P). Each experimental diet was formulated either as a positive control containing 3.2 g/kg non-phytate phosphorus (NPP), with the addition of dicalcium phosphate (DCP), or as a low P one, without DCP addition. Both low P diets (containing 1.3 or 1.1 g/kg NPP) were supplemented with microbial phytase at 0, 150, 300 and 450 U/kg. The birds were housed in cages, allocating two hens per cage as the experimental unit. Each of 10 dietary treatments was assigned to 16 replicates. Low dietary NPP (below 1.3 g/kg) was not able to support optimum performance of hens during the laying cycle (from 22 to 46 weeks of age), either in maize or barley diets. Rate of lay, daily egg mass output, feed consumption, tibia ash percentage and weight gain were reduced in hens fed low NPP diets. The adverse effects of a low P diet were more severe in hens on a maize diet than in those on a barley diet. Low dietary NPP reduced egg production, weight gain, feed consumption and tibia ash content and microbial phytase supplementation improved these parameters. Hens given low NPP diets supplemented with phytase performed as well as the hens on positive control diets containing 3.2 g/kg of NPP. A 49% reduction of excreta P content was achieved by feeding hens on low NPP diets supplemented with phytase, without compromising performance. Phytase addition to low NPP diets increased total phosphorus absorption at the ileal level, from 0.25 to 0.51 in the maize diet and from 0.34 to 0.58 in the barley diet. Phosphorus absorption increased linearly with increasing levels of dietary phytase. Mean phosphorus absorption was higher in barley diets than in maize diets (0.49 vs 0.39).  相似文献   

3.
1. The effects of different dietary concentrations of calcium (Ca), available phosphorus (AP) and vitamin D (D) on 5- to 16-day growth performance, and aspects of calcium and phosphorus (P) metabolism of chickens from three commercial strains were studied in two experiments. 2. Increasing dietary Ca reduced weight gain, tibia Ca and P content and increased plasma total Ca, Ca consumption and excretion, whilst dietary Ca at 32 g/kg increased tibia Ca:P ratio, plasma ionized calcium and reduced plasma P, tibia ash, P excretion, excreta moisture and Ca retention. 3. Increasing dietary AP reduced plasma total and ionized Ca and excreta moisture and increased P consumption and excretion, plasma P and tibia ash. 4. The addition of vitamin D increased plasma total and ionized Ca, tibia Ca:P ratio and reduced plasma sodium and P concentrations. 5. Strains differed in their tibia contents of Ca and Ca:P ratios, in response to Ca, AP and vitamin D diets whilst they differed in Ca excretion and excreta moisture caused by feeding either dietary Ca or AP. 6. It was concluded that dietary Ca, AP, vitamin D and strain of broiler chickens influenced the metabolism of Ca and P and that, as a consequence, the tolerance to high dietary Ca. A lean strain of chickens tolerated high dietary calcium better than its fat counterparts.  相似文献   

4.
1. Two experiments were conducted to assess the effects of lighting regime, dietary calcium source and sodium bicarbonate on production variables and egg shell quality of White Leghorn hens. In both experiments, hens were assigned to one of three lighting programmes that provided evening, morning or intermittent (midnight) lighting supplements in addition to natural daylight. Experimental diets used in the first study were formulated to contain (1) ground oyster shell flour, (2) limestone flour, or (3) and (4) the same +2/3 of the calcium source as hen-size oyster shell grit. The same 4 diets plus those containing hen-size limestone or hen-size limestone and oyster shells were used in experiment II. Additionally, diets in the first experiment contained either 0 or 10 g/kg sodium bicarbonate. 2. Hen-day egg production and food consumption were not affected by any of the experimental treatments. Hens fed on oyster shell diets or exposed to intermittent lighting regimes laid eggs of the highest specific gravity. Shell quality, as measured by specific gravity, was not affected by the addition of dietary sodium bicarbonate. 3. As expected, elevated temperatures (greater than 32 degrees C) significantly reduced egg shell quality. However, this effect was variable particularly in experiment II which used younger hens. 4. The shell quality of eggs from hens exposed to intermittent lighting in experiment II was significantly higher in each of the 4 sampling periods: morning (08.00-12.00), afternoon (12.00-16.00), evening (16.00-20.00) and night (20.00-08.00). 5. It is suggested that midnight lighting programmes provide a means of supporting egg shell quality of older laying hens during the summer months without a significant reduction in egg production.  相似文献   

5.
A 3 x 2-factorial balance trial was conducted with dietary concentrations of P below the requirement (3.6, 4.3 and 5.0 g/kg DM) and Ca below or at the requirement (28 and 37 g/kg DM) adjusted by monobasic calcium phosphate (MCP, Ca(H2PO4)2) and calcium carbonate (CaCO3). The diets were mainly based on maize and soybean meal. Six 18-week old laying hens were allocated to each of the diets, and excreta were quantitatively collected for 21 days from week 22 of age onwards. Feed allowance was 95 g/d according to pre-treatment ad libitum intake of the hens receiving the lowest P concentration. After the balance trial was terminated, ileal digesta was obtained from each hen, and the flow at the terminal ileum was calculated using TiO2 as indigestible marker. Linear regression analysis was applied to determine the effect of supplementary P. Hens were in a negative energy balance, indicated by a loss in BW across all treatments. Intake and excretion of both N and energy were not significantly affected by the P or Ca content of the diet. P from supplemented MCP was almost completely recovered in excreta, irrespective of dietary Ca concentration. At the terminal ileum, however, the P flow was not significantly affected by the MCP supplementation. Net absorption of P from MCP was almost complete until the terminal ileum, but P was re-directed into the excreta, likewise via the urine. The supplementation of Ca reduced praecaecal net absorption and utilisation of P from the basal diet, likewise due to a reduced phytate hydrolysis. It is suggested by the data, that comparative measurements of P availability for laying hens should be conducted on the basis of praecaecal net absorption rather than on total excretion measurements.  相似文献   

6.
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7.
The present study was conducted to investigate the effect of dietary Rhodobacter capsulatus on lipid fractions and egg‐yolk fatty acid composition in laying hens. Thirty‐six laying hens (30 weeks old) were randomly assigned into two dietary groups fed diets with (0.04%) or without (control) R. capsulatus for a 60‐day feeding trial. Dietary R. capsulatus decreased (p < 0.05) serum and hepatic cholesterol and increased (p < 0.05) the excreta cholesterol, and resultant lower (p < 0.05) cholesterol contents in egg yolk. The concentration of polyunsaturated fatty acids (PUFA) and ratio to saturated fatty acids in egg yolk was improved (p < 0.05) by dietary R. capsulatus. The concentration of hepatic bile acid was increased (p < 0.05) and excreta bile acid was decreased (p < 0.01) in the laying hens fed R. capsulatus diet. The incorporation of 1‐14C‐palmitic acid into hepatic lipids and lipid fractions was increased (p < 0.05) in laying hens fed R. capsulatus diet. Moreover, dietary R. capsulatus did not appear to cause any adverse effects on laying hen performances. Therefore, dietary supplementation of R. capsulatus in layer diets may be a feasible means of producing eggs with lower cholesterol and higher PUFA contents for health conscious consumers.  相似文献   

8.
本试验旨在研究不同比例膨化棉籽粕替代豆粕对蛋鸡生产性能、蛋品质及血清生化指标的影响.选取40周龄海兰褐蛋鸡360羽,随机分成5组,每组4个重复,每个重复18羽.对照组饲喂玉米-豆粕型基础饲粮,试验1组用6％普通未膨化棉籽粕替代豆粕,试验2、3、4组分别用6％、8％、10％的膨化棉籽粕替代豆粕,试验期8周.结果表明:1)饲粮中不同比例膨化棉籽粕对蛋鸡生产性能影响不显著(P＞0.05),而试验1组产蛋率和平均蛋重显著低于对照组(P＜0.05),料蛋比显著高于对照组(P＜0.05).2)与对照组相比,各试验组蛋黄颜色均显著加深(P＜0.05),而试验1、4组蛋白高度显著降低(P＜0.05).饲粮添加棉籽粕对蛋壳强度和蛋壳厚度无显著影响(P＞0.05).3)试验1组总蛋白、钾含量均显著低于对照组(P＜0.05),谷丙转氨酶活性显著高于对照组和试验2组(P＜0.05),尿酸含量显著高于试验2组(P＜0.05);试验4组血清总钙含量显著低于对照组(P＜0.05).随着膨化棉籽粕添加量的增加,血清总蛋白、总钙和钾含量均逐步降低,谷丙转氨酶活性则逐步升高,呈现一定的剂量-效应关系.饲粮添加棉籽粕对血清白蛋白含量无显著影响(P＞0.05).由此可见,蛋鸡饲粮中添加8％膨化棉籽粕对蛋鸡生产性能、蛋品质及血清生化指标无明显影响.棉籽粕膨化处理能有效降低游离棉酚对蛋鸡生产性能和蛋品质等的影响,提高蛋鸡对棉籽粕的利用能力.  相似文献   

9.
1. The influence of a microbial phytase on the performance, toe ash contents and nutrient utilisation of male broilers fed diets based on maize and wheat was investigated. The experiment was conducted as 2 x 2 x 2 factorial arrangement of treatments. Within the factorial, two diet types (maize-soy or wheat-soy) containing two levels of non-phytate phosphorus (3.0 or 4.5 g/kg) were evaluated and each level of non-phytate phosphorus was supplemented with 0 or 500 PU phytase/kg diet. Each of the 8 dietary treatments were fed to 6 pens of 8 birds from d 1 to 21 post-hatching. 2. Main effects of diet type and phytase were observed for all parameters. Main effect of non-phytate phosphorus was significant only for feed/gain and toe ash contents. Phytase addition improved weight gains irrespective of diet type or non-phytate phosphorus level, but the magnitude of improvement in the phosphorus-deficient wheat-soy diet was greater, resulting in a diet type x non-phytate phosphorus interaction. Responses in toe ash contents were noted only in phosphorus-deficient diets, as indicated by a non-phytate phosphorus x phytase interaction. 3. Phytase addition improved apparent metabolisable energy values of wheat-based diets, but had little effect on the apparent metabolisable energy of maize-based diets as shown by a diet type x phytase interaction. The apparent metabolisable energy was not influenced by dietary non-phytate P. 4. Phytase improved ileal nitrogen digestibility in both diet types, but the responses to added phytase tended to be higher in wheat-based diets, as shown by a diet type x phytase interaction. 5. Increasing the dietary non-phytate phosphorus level reduced phosphorus digestibility and increased excreta phosphorus content. Addition of phytase improved phosphorus digestibility, but the increments were higher in low phosphorus diets resulting in a non-phytate phosphorus x phytase interaction. Phytase addition tended to lower the excreta phosphorus content, but the effects were greater in birds fed low phosphorus diets, as shown by a non-phytate phosphorus x phytase interaction.  相似文献   

10.
1. Alterations in dietary metabolisable energy (ME) concentration had a limited influence on food and nutrient intakes and egg mass output of hens in early lay kept at the prevailing air (10 degrees to 24 degrees C), cold (6 degrees to 16 degrees C) or hot (25 degrees to 35 degrees C) temperatures. 2. Energy intakes were not improved by increasing the dietary concentrations of nutrients other than energy. 3. At prevailing air and cold temperatures all dietary ME-nutrient density combinations allowed hens to meet the recommended daily protein intake but only hens fed the most concentrated diets were able to meet this recommendation at hot temperatures. 4. Even the highest intakes of ME and protein achieved at hot temperatures failed to increase egg mass output to the values attained on any diet at cold temperatures.  相似文献   

11.
OBJECTIVE: To determine whether plasma, urine, and fecal electrolyte and mineral concentrations differ between clinically normal horses and Thoroughbreds with recurrent exertional rhabdomyolysis (RER) after consumption of diets varying in cation-anion balance. ANIMALS: 5 Thoroughbred mares with RER and 6 clinically normal mixed-breed mares. PROCEDURE: Each of 3 isocaloric diets designated as low, medium, and high on the basis of dietary cation-anion balance (DCAB) values of 85, 190, and 380, respectively, were fed to horses for 14 days. During the last 72 hours, 3 horses with RER and 3 control horses had daily urine and fecal samples obtained by total 24-hour collection. Remaining horses had urine samples collected daily by single catheterization. RESULTS: For each diet, no differences existed between horses with RER and control horses in plasma pH, electrolyte concentrations, and creatine kinase activity or in urine pH and renal fractional excretion (FE) values. Plasma pH, strong ion difference, bicarbonate and total carbon dioxide concentrations, and base excess decreased and plasma chloride and ionized calcium concentrations increased with decreasing DCAB. Urine pH decreased with decreasing DCAB. The FE of chloride and phosphorus were greatest for horses fed the low diet. The FE values for all electrolytes exept magnesium did not differ between urine samples obtained by single catheterization and total 24-hour collection. Daily balance of calcium, phosphorus, sodium, chloride, and potassium did not differ significantly among horses fed the various diets. CONCLUSIONS: In clinically normal horses and in horses with RER, the DCAB strongly affects plasma and urine pH and the FE of sodium, potassium, chloride, and phosphorus.  相似文献   

12.
900羽21周龄海兰褐蛋鸡随机分成5组,每组6个重复,每个重复30羽。分别在基础日粮中添加0、0．1％、0．5％、2．5％、5％NaHCO3,持续10周。结果显示,与对照组相比,0．1％组蛋鸡盲肠乳酸菌数量增加,大肠杆菌数量降低,菌群多样性指数提高（P〉0．05）。0．5％组蛋鸡粪便pH值显著提高（P〈0．05）,乳酸菌数量增加,菌群多样性指数提高（P〉0．05）。2．5％、5％组蛋鸡粪便pH值、水分含量极显著高于其他组（P〈0．01）。同时,2．5％、5％组盲肠乳酸杆菌数量降低（P〉0．05或P〈0.05）,大肠杆菌数量增高（P〉0．05或P〈0．05）,5％组菌群多样性指数亦显著降低前3组（P〈0．05）。结果表明,日粮添加NaHCO3超过2．5％,蛋鸡腹泻严重,肠道菌群平衡严重破坏。而当NaHCO3的添加量低于0．5％时,肠道有益菌数量和菌群多样性指数呈增加趋势,蛋鸡生产性能维持正常。因此,本试验提示蛋鸡生产中饲料添加剂NaHCO3最高耐受量为0．5％。  相似文献   

13.
理想氨基酸模式下低粗蛋白质饲粮对蛋鸡生产性能的影响   总被引：1，自引：0，他引：1  
本试验旨在研究以理想氨基酸(AA)模式配制的低粗蛋白质(CP)饲粮对21～32周龄蛋鸡生产性能、蛋品质、全血氨浓度和血浆尿酸浓度及粪氮含量的影响.试验选用540只体重相近的健康海兰灰蛋鸡,随机分为5组,每组6个重复,每个重复18只鸡,分别饲喂等能量( 11.00 MJ/kg)的5种CP水平(17.00％、16.50％、16.00％、15.50％和15.00％)的饲粮,试验期12周.结果表明:在理想AA模式下降低饲粮CP水平,蛋鸡产蛋率显著提高(P＜0.05),平均蛋重有降低的趋势(P=0.06),但对平均日采食量、日产蛋重和蛋料比无显著影响(P＞0.05);降低饲粮CP水平极显著影响了蛋白高度和哈氏单位(_P＜0.01),显著影响了蛋黄颜色(P＜0.05),未显著影响蛋壳厚度和蛋壳强度(P＞0.05);饲粮CP水平对各鸡蛋成分均无显著影响(P＞0.05),但鸡蛋蛋白含量随饲粮CP水平的降低有降低的趋势(P=0.09);饲粮CP水平对血浆尿酸浓度及全血氨浓度均无显著影响(P＞0.05);降低饲粮CP水平极显著降低了蛋鸡粪氮含量(P＜0.01).由此可见,在理想AA模式下,适当降低饲粮CP水平可提高蛋鸡产蛋率,改善鸡蛋品质,降低粪氮含量.  相似文献   

14.
Re-evaluation of calcium and phosphorus requirements in aged laying hens   总被引：2，自引：0，他引：2  
1. A series of 5 trials was conducted with 401- to 650-d-old Lohmann, Yafa (local breed with brown eggshells) and Yarkon (local breed with white eggshells) hens fed for 56 to 84 d with diets containing 25 to 50 g/kg calcium (Ca) and 4.5 to 7.6 g/kg phosphorus (P). 2. Increasing dietary Ca from 24-25 to 36-40 g/kg improved egg production, shell weight (SW) and shell thickness (ST), and decreased mortality. 3. Increasing dietary Ca to 48 to 50 g/kg did not affect egg production but increased SW and/or ST. In one out of the 4 trials, this effect was not significant, most likely because of the high shell quality of the eggs from the Yafa hens used for this trial. 4. Dietary P content of 4.5 g/kg (1.0 g/kg added inorganic P) appears to be sufficient for maintaining egg production and shell quality in aged laying hen given 36 to 40 g/kg Ca. 5. Increasing dietary Ca above 40 g/kg may require a higher dietary P content.  相似文献   

15.
1. Palm kernel meal (PKM), brewers dried grains (BDG) and maize offal (MO) were included in broiler diets, each at 100, 150 or 200 g/kg; the diets were fed up to 35 d of age. 2. Overall food intake and weight gain decreased in the order BDG, PKM and MO. There were, however, significant interactions between the test ingredients and dietary concentrations in all the growth responses. Food intakes increased with the dietary concentrations of each test ingredient, but the increase was greater for BDG than PKM or MO. For weight gain, at 100 g/kg, the final body weights of the chicks fed on the diets with BDG and MO were similar, and those of chicks fed on the diet with PKM slightly lower. However, at 200 g/kg, growth rate of chicks fed on the BDG and PKM diets were similar while those of chicks fed on the MO diet was 7% lower. Efficiency of food utilisation was similar at 100 g/kg for all the ingredients and decreased as their concentrations increased; however, the decrease was considerably less for the PKM than for the MO and BDG diets. 3. Broilers fed on the BDG-based diets voided most excreta followed by those fed on the PKM and MO diets; excreta water content was highest from birds fed on the MO diets followed by the PKM and BDG diets. Apparent retention of dry matter was similar with all the test ingredients, but it decreased only significantly at 200 g/kg dietary concentration. The rate of passage was faster with the PKM diets followed by the MO and BDG diets; it was increased at 200 g/kg dietary concentration of the test ingredients.  相似文献   

16.
A corn-soybean meal diet was supplemented with 0, 1, or 2% Improved Milbond-TX (IMTX, a hydrated sodium calcium aluminosilicate) for Hy-Line W-36 laying hens selected for good or poor eggshell quality. Supplementing the diet with IMTX had no detrimental effects on egg weight, eggshell weight, albumen quality, feed consumption, or feed conversion during 5 consecutive 28-d periods. Increase in BW over the 5-mo experimental period was not influenced by the addition of IMTX. Results from this study show that an accidental oversupplementation of a laying hen diet with up to 8 times the recommended level of IMTX of the manufacturer, which may occur due to a feed mill mixing error, should not result in adverse performance of laying hens nor should it affect the concentration of moisture in the excreta.  相似文献   

17.
This study examined the effects of various levels of dietary nonphytate phosphorus on laying performance and the expression patterns of phosphorus metabolism related genes in Dwarf pink-shell Jaying hens. A total of 405 28-week-old Dwarf pink-shell laying hens were fed the same corn-soybean basal meals but containing 0.20%, 0.25%, 0.30%, 0.35% or 0.40% nonphytate phosphorus. The results showed that feed intake, egg production, and average egg weights were quadratically correlated with dietary nonphytate phosphorus content （P 〈 0.05）, and the highest egg production, feed intake and average egg weights were achieved when dietary nonphytate phosphorus was at 0.3% （P 〈 0.05）. mRNA expression of intestinal sodium phosphorus co-transporter linearly decreased when dietary nonphytate phosphorus increased, mRNA and protein expression of intestinal calbindin and vitamin D receptor correlated quadratically with dietary nonphytate phosphorus, and the highest expression was found when dietary available phosphorus was at 0.2,5% to 0.3%. In conclusion, the ideal phosphorus requirement for Dwarf pink-shell layer hens is estimated to be 0.3% in a corn-soybean diet. With this level of phosphorus supplementation, calbindin and vitamin D receptor reached their highest expression.  相似文献   

18.
The objective of this study was to determine the effects of rare earth element‐enriched yeast (RY) on egg production, coefficient of total tract apparent digestibility (CTTAD), egg quality, excreta gas emission and excreta microbiota of laying hens. A total of 216 ISA brown laying hens of 52 weeks of age were used in a 5‐week feeding trial and data were collected every week. Birds were randomly allotted to three dietary treatments each with six replicates and 12 hens per replicate. Each cage (38 cm width × 50 cm length × 40 cm height) contained one hen. Treatments consisted of corn–soya bean meal‐based diet supplemented with 0, 500 or 1000 mg/kg of RY. From weeks 55 to 56, inclusion of RY linearly increased (p < 0.05) egg production. The CTTAD of nitrogen was increased (linear, p < 0.05) with increasing dietary level of RY. In week 55, yolk height and Haugh units were increased linearly (p < 0.05) with increasing dietary RY content. However, no significant effects were observed in terms of excreta emissions and excreta microbiota in laying hens. In conclusion, dietary supplementation with RY improved egg production and CTTAD of nitrogen and slightly improved egg quality in laying hens of the late period of peak egg production.  相似文献   

19.
为研究长期饲喂亚麻籽对蛋鸡生产性能和表观消化代谢的影响,试验选用48只体重相近的55周龄健康海兰褐蛋鸡,随机分成4组,每组12只,即试验1、2、3和4组分别在基础日粮中添加0、6%、12%和18%亚麻籽,饲喂10周。结果表明,试验2、3组对蛋鸡增重无影响(P>0.05),试验4组蛋鸡体重显著下降(P<0.05);各试验组排泄物的水分含量无显著变化(P>0.05);试验2组可提高产蛋性能,试验3组可改善部分产蛋性能,但试验4组能降低产蛋性能。对于营养物质的消化代谢,试验2组不影响日粮表观代谢能和营养物质表观代谢率,试验3组显著降低能量表观代谢率和磷表观代谢率(P<0.05),试验4组降低能量及多项营养物质表观代谢率。提示,日粮中添加6%亚麻籽可用于长期饲喂蛋鸡。  相似文献   

20.
分析了中华蚱蜢粉的营养成分,观察了其干粉加钙磷取代饲料鱼粉对蛋鸡生产性能和蛋品质的影响。结果表明:相对于基础日粮组,中华蚱蜢粉加钙磷干粉取代鱼粉可以使蛋鸡产蛋率、蛋均重、料蛋比等生产性能得到提高(P<0.05),但对耗料量、破蛋率、蛋壳厚度、蛋壳百分率、哈氏单位和蛋形指数等指标影响不大(P>0.05)。显示了其可取代饲料中的鱼粉的功能。  相似文献   

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