Effect of dietary defatted diatom biomass on egg production and quality of laying hens

Background

This study was to determine if feeding laying hens with defatted diatom microalgal biomass (DFA) from biofuel production affected their egg production and health status.

Methods

Five replicates of 5 individually caged ISA Babcock White leghorn hens were fed 4 diets, including a corn-soybean meal control diet, a diet containing 7.5% DFA substituting for soybean meal, and diets containing 7.5% or 15% DFA substituting for corn and soybean meal. Body weights, feed intake, feed conversion ratio (FCR), rate of egg production, egg size, egg mass, and several characteristics of eggs were determined at 4 and 8 wk. Venous blood was sampled at 4 and 8 wk for measurement of 5 biomarkers of health.

Results

The 15% DFA diet decreased (P <?0.05) feed intake, egg production, and plasma uric acid concentrations as compared with the control diet, but increased (P <?0.05) egg albumen weight and height compared with the 7.5% DFA diets. The two levels of DFA produced dose-dependent (P <?0.05) changes in three color measures of egg yolk, without affecting four hen plasma biochemical indicators of health.

Conclusions

Feeding laying hens with 7.5% DFA in the corn-soybean meal diet for 8 wk had no adverse effect on their health, egg production, or egg quality, but 15% inclusion reduced feed intake, egg production, and efficiency of feed utilization.     

An Escherichia coli phytase expressed in yeast effectively replaces inorganic phosphorus for finishing pigs and laying hens

Two experiments determined the efficacy of an Escherichia coli phytase (ECP) added to P-deficient, corn-soybean meal diets fed to finishing pigs and second-cycle laying hens. Sixty finishing pigs (49 +/- 0.9 kg) were formed into blocks within sex based on weight and ancestry and allotted to a P-deficient diet unsupplemented or supplemented with 0.10% inorganic P (iP) from KH2PO4 or ECP at 250, 500, 1,000, or 10,000 phytase units (FTU)/kg. Individually fed pigs were allowed ad libitum access to the experimental diets until a BW of 120 +/- 3 kg was achieved, at which time the pigs were euthanized and the left fibula and fourth metatarsal were excised for determination of bone ash. Pigs were fed a 2-phase diet program for early- and late-finishing pigs; available P in the basal diets was set 0.10% below the requirement. Dietary supplementation of iP or ECP increased weight gain (P < 0.10) and G:F (P < 0.01); performance was not different (P > 0.13) among the phytase-supplemented groups. Fibula ash was greatest (P < 0.01) for pigs fed diets containing 10,000 FTU of ECP/kg. Two hundred forty second-cycle hens were allotted to a P-deficient diet or a P-deficient diet supplemented with 0.10% iP or ECP at 150, 300, or 10,000 FTU/kg for a 12-wk experiment. The basal diet was a corn-soybean meal diet with no added iP (17% CP, 3.8% Ca, 0.10% available P). Hens fed the P-deficient diet were removed from the experiment after 4 wk due to poor egg production. Supplementation of iP or ECP resulted in increased (P < 0.01) feed intake, egg weight, and egg production during the first 4 wk. During the entire 12-wk period, there were no differences (P > 0.28) between the iP- and ECP-supplemented groups in feed intake, egg weight, or egg production. These experiments reveal that ECP was as efficacious as supplemental iP and that supplementation of an excess dose of ECP was efficacious and without negative effects in finishing pigs and laying hens.     

不同日粮组成对蛋鸡生产性能及鸡蛋品质的影响

选用５７６只１５４日龄海赛克斯蛋鸡探讨不同日粮组成对蛋鸡生产性能及鸡蛋品质的影响。共计３个处理，每个处理４个重复，每个重复４８只鸡，全阶梯三层笼养，自由采食、饮水，进行产蛋率大于８０％的饲养试验。试验期为４周。试验结束后，对各处理的产蛋率、只日产蛋量、料蛋比、破蛋率、每千克蛋耗料成本及蛋的品质指标进行统计分析。试验结果表明，采食３种日粮的试鸡在产蛋量、破蛋率、采食量等指标差异不显著（Ｐ＞０．０５），但采食无鱼粉日粮的试鸡料蛋比、死淘率最低，每千克蛋饲料成本最低（Ｐ＜０．０５），且产蛋率最高（Ｐ＜０．０５）。蛋形指数、蛋壳厚度、蛋壳强度、哈氏单位４项指标上３个处理间无明显差异（Ｐ＞０．０５）。     

乳酸锌对蛋鸡生产性能及蛋壳质量的影响

本试验旨在研究乳酸锌对蛋鸡生产性能及蛋壳质量的影响。试验采用单因子随机分组试验设计,选取1600只360日龄的罗曼粉壳蛋鸡,随机分到4个处理组,各处理组8个重复,每个重复50只鸡。基础饲粮采用为玉米－豆粕型粉状饲粮,处理1饲喂基础饲粮＋60mg／kg－水硫酸锌（以锌计）,处理2饲喂基础饲粮＋60mg／kg乳酸锌（以锌计）,处理3饲喂基础饲粮＋40mg／kg乳酸锌（以锌计）,处理4饲喂基础饲粮＋60mg／kg锌（－水硫酸锌和乳酸锌提供的锌各一半）。试验结果表明,在产蛋鸡饲粮中100％以乳酸锌替代硫酸锌（提供的锌含量为60mg／kg）,能显著降低平均破蛋率,提高平均蛋壳强度和平均蛋壳厚度（P〈0．05）,死亡率最低,对蛋鸡的平均产蛋率、平均蛋重、平均日采食量和平均料蛋比无显著影响（P〉0．05）。     

日粮中添加辣诺素对海兰褐蛋鸡产蛋性能和蛋品质的影响

本试验旨在研究日粮中添加辣诺素（辣木和诺丽果的提取物）对蛋鸡生产性能及蛋品质的影响。将产蛋高峰期（22周龄）的海兰褐商品蛋鸡540只随机分为6个处理,每个处理6个重复,每个重复15只鸡。负对照组（NC）饲喂基础日粮,正对照组（PC）饲喂添加50 mg/kg杆菌肽锌的基础日粮,4个试验组分别饲喂添加0.25、0.50、0.75和1.00 g/kg辣诺素（LNS）的基础日粮。试验期24周。结果显示：①日粮处理对蛋鸡试验前期和后期生产性能均无显著影响（P>0.05）,试验后期添加0.50和0.75 g/kg辣诺素有改善料蛋比的趋势（P=0.087）;日粮处理对试验前期和后期鸡蛋蛋形指数、蛋壳强度、蛋壳厚度、蛋黄重和哈氏单位均无显著影响（P>0.05）,但日粮中添加杆菌肽锌和辣诺素有提高蛋壳强度的趋势（P=0.062）,其中以添加0.75g/kg辣诺素组鸡蛋强度最高。②与正、负对照组相比,添加辣诺素显著增加了生蛋黄和熟蛋黄的罗氏蛋黄色比率（P<0.05）,显著降低了蛋黄胆固醇的含量（0.25 LNS组除外）（P<0.05）。③与负对照组相比,添加0.50 g/kg辣诺素显著提高了鸡蛋总黄酮、二十二碳六烯酸（DHA）、卵磷脂、亚麻酸和亚油酸含量（P<0.05）。综合以上试验结果,辣诺素作为饲料添加剂具有提高鸡蛋营养品质的功能,考虑到添加成本,产蛋鸡日粮中添加0.25~0.50 g/kg为宜。     

乳酸锌对蛋鸡生产性能及蛋壳质量的影响

为研究乳酸锌对蛋鸡生产性能及蛋壳质量的影响,试验采用单因子随机分组试验设计,选取1600只360日龄的罗曼粉壳蛋鸡,随机分为4个处理组,每个处理组8个重复,每个重复50只鸡。础饲日粮为玉米-豆粕型粉状饲粮,处理1组饲喂基础饲粮+60 mg/kg一水硫酸锌(以锌计),处理2组饲喂基础饲粮+60 mg/kg乳酸锌(以锌计),处理3组饲喂基础饲粮+40 mg/kg乳酸锌(以锌计),处理4组饲喂基础饲粮+60 mg/kg锌(一水硫酸锌和乳酸锌提供的锌各一半)。结果表明,蛋鸡日粮中添加60 mg/kg乳酸锌(以锌计)能显著降低平均破蛋率、提高平均蛋壳强度(P<0.05)和明显提高平均蛋壳厚度,并且平均死亡率最低,但对蛋鸡的平均产蛋率、平均蛋重、平均日采食量和平均料蛋比无显著影响(P>0.05)。     

低豆粕日粮对产蛋鸡生产性能及蛋品质的影响

试验选用1 600只生产性能相同、体况良好的33周龄罗曼蛋种鸡,随机分为4组,在总蛋白质含量相同和满足必需氨基酸需要量的情况下,用价格较低的蛋白饲料取代蛋鸡日粮中豆粕,研究氨基酸平衡的低豆粕日粮对蛋种鸡生产性能和蛋品质的影响。结果表明:氨基酸平衡的低豆粕日粮对蛋鸡产蛋率、种蛋合格率、健雏率、蛋形指数、蛋比重、蛋壳厚度、哈氏单位等指标无显著影响(P>0.05),但当日粮中的豆粕含量降低8～15个百分点时,蛋种鸡的日平均蛋重、日采食量、受精率、孵化率等显著低于正常豆粕日粮(P<0.05),而考虑综合因素日粮中的豆粕含量降低8个百分点的第1组,与正常豆粕日粮相比,差异不显著(P>0.05),而且能降低饲料成本,可以提高蛋鸡养殖效益,具有实际意义。     

Yeast Culture Supplementation to Laying Hen Diets Containing Soybean Meal or Sunflower Seed Meal and Its Effect on Performance,Egg Quality Traits,and Blood Chemistry

This study was designed to investigate the effects of yeast culture supplementation to laying hen diets containing 2 oilseed meals on performance, egg traits, and some blood parameters. A total of 180 Lohmann Brown laying hens 21 wk of age were allocated to 4 dietary treatments and fed for 16 wk. Two different basal diets were prepared; one contained soybean meal and the other contained sunflower seed meal. Both of the basal diets were supplemented with 0 and 2 g/kg commercial yeast culture product (Saccharomyces cerevisiae). Yeast culture supplementation to diets containing either oilseed meal did not significantly affect feed intake, hen-day egg production, feed efficiency, interior and exterior egg quality characteristics, serum levels of total protein, triglyceride, cholesterol, alanine amino transferase, aspartate amino transferase, and alkaline phosphatase. Body weight gain (P < 0.05), egg weight (P < 0.001), and serum uric acid (P < 0.05) were increased with yeast culture supplementation. The reduction in egg yolk cholesterol was significant (P < 0.001) in the groups fed yeast-supplemented diets. The results in this study demonstrated that yeast culture supplementation to the diets containing soybean meal or sunflower seed meal increased egg weight and decreased egg yolk cholesterol without affecting performance and egg traits, but serum uric acid concentration was increased.     

The effects of formic acid-treated shrimp meal on laying performance and egg quality in aged laying hens

An experiment was carried out to measure the suitability of using formic acid-treated shrimp meal (TSM) as a protein source for aged laying hens. Shrimp meal (SM), air-dried shrimp waste was treated with 3% formic acid (w/v) at room temperature for 20 min, sun-dried, ground to pass through 1.0 mm mesh screen and then ready to use as the TSM. A total of 56 Single Comb White Leghorn hens, 85 wk of age, were placed in individual cages and assigned randomly into 7 dietary groups of 8 birds each. A control diet, diets containing 5, 10, and 15% SM and diets containing 5, 10, and 15% TSM were prepared. Diets and water were given ad libitum during the 30-d experimental period. Hen-day egg production, egg mass, feed intake, and feed conversion ratio (FCR) were deteriorated with increasing levels of the SM in the diets (P < 0.05). In contrast, these parameters were unchanged with increasing levels of the TSM in diets and compatible with the control group. No significant improvements were observed in exterior or interior egg quality among the dietary groups, except for eggshell weight, strength and yolk color, which were significantly increased in SM and TSM groups when compared to the values in control group (P < 0.05). It is concluded that inclusion of TSM up to 15% in laying hen diets may have beneficial effects on laying performance along with improved eggshell quality and yolk color, and suggested that TSM is a promising combined source of protein and calcium in aged laying hens.     

乳酸锌对蛋鸡生产性能及蛋壳质量的影响试验

本试验旨在研究乳酸锌对蛋鸡生产性能及蛋壳质量的影响。试验采用单因子随机分组试验设计,选取1600只360日龄的罗曼粉壳蛋鸡,随机分到4个处理组,各处理组8个重复,每个重复50只鸡。基础饲粮采用为玉米-豆粕型粉状饲粮,处理1饲喂基础饲粮＋60mg／kg-水硫酸锌（以锌计）;处理2饲喂基础饲粮＋60mg／kg乳酸锌（以锌计...     

Effect of dietary nonphytate phosphorus on laying performance and small intestinal epithelial phosphate transporter expression in Dwarf pink-shell laying hens

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.     

Performance and Egg Characteristics of Laying Hens Fed Diets Incorporated with Poultry By-Product and Feather Meals

The effects of poultry by-product meal (PBPM) and feather meal (FM) incorporated separately and in combination in the diet on laying hen performance and egg characteristics during postpeak production were determined. Bovans White strain laying hens, 42 wk of age, were fed diets with 0% PBPM and FM, 5% FM, 5% PBPM, or 4% FM + 4% PBPM. Egg production, feed intake, and egg mass were not significantly affected by dietary treatments, whereas egg weight and feed conversion ratio (FCR) were significantly affected. Egg weights of hens receiving 4% FM + 4% PBPM were significantly lower than those fed the control diet, whereas those fed 5% FM or 5% PBPM were intermediate. FCR was significantly improved by the diets containing 5% FM or 5% PBPM compared with the diet containing 4% FM + 4% PBPM. Dietary PBPM decreased Haugh units, but FM did not. Egg breaking strength, shell weight, and weights of albumen and yolk were not affected by treatments. The results suggested that FM or PBPM could be incorporated up to 5% singly or up to 8% in combination in layer diets but with possible detrimental effects on Haugh units, egg weight, and FCR.     

膨化棉籽粕对蛋鸡生产性能、蛋品质及血清生化指标的影响

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.     

酶制剂、益生素对杂粕饲粮品质改善效果的研究

采用单因素完全随机设计,研究杂粕日粮中添加0.015%的酶制剂和0.15%的益生素与豆粕日粮饲喂蛋鸡的效果差异。结果表明,与豆粕相比,加酶或加益生素的杂粕日粮降低蛋鸡产蛋率、产蛋量、蛋重和蛋鸡采食量;通过添加益生素或酶制剂,杂粕日粮在饲料转化率上与豆粕日粮效果相当;与豆粕日粮相比,加酶或加益生素的杂粕日粮不影响蛋壳厚度和软破蛋率,也不影响能量和蛋白质代谢率,但显著降低排泄物中蛋白质含量。可见,一定程度上加酶或加益生素能可提高杂粕的利用率,但其实用效果与豆粕日粮还有一定差距。     

不同饲粮粗蛋白质水平下蝇蛆蛋白替代豆粕对蛋鸡生产性能、蛋清品质及血清蛋白质代谢指标的影响

本试验旨在研究不同饲粮粗蛋白质水平下蝇蛆蛋白替代豆粕对蛋鸡生产性能、蛋清品质及血清蛋白质代谢指标的影响。采用单因素试验设计,选取252只产蛋率、体重相近的健康33周龄罗曼白蛋鸡,随机分为3组,每组7个重复,每个重复12只鸡。各组分别饲喂标准回肠可消化氨基酸(SIDAA)平衡模式下配制的不同粗蛋白质水平(16.50%、14.85%、13.20%)的玉米-豆粕-蝇蛆蛋白饲粮,各组蝇蛆蛋白与豆粕提供等量的粗蛋白质。预试期2周,正试期12周。结果表明:1)与16.50%组相比,14.85%组的产蛋率、平均蛋重、产蛋量、平均日采食量和料蛋比均无显著差异(P>0.05);13.20%组的料蛋比显著增加(P<0.05),产蛋率、产蛋量、平均蛋重和平均日采食量均显著降低(P<0.05)。2)与16.50%组相比,14.85%组的平均蛋重、蛋清重、浓蛋白重、蛋白高度、哈氏单位和蛋清比例均无显著差异(P>0.05);13.20%组的平均蛋重、蛋清重、浓蛋白重和蛋白高度显著降低(P<0.05),而蛋清比例、哈氏单位无显著差异(P>0.05)。3)各组血清谷草转氨酶、谷丙转氨酶活性及总蛋白、白蛋白、尿酸含量无显著差异(P>0.05),且输卵管膨大部组织学形态正常。由此可见,在本试验条件下,使用蝇蛆蛋白替代豆粕并使饲粮粗蛋白质水平降低至14.85%时未对蛋鸡生产性能和蛋清品质产生不良影响,但饲粮粗蛋白质水平降低至13.20%时则会产生不利影响。     

Effect of enzyme preparation containing xylanase and beta-glucanase on performance of laying hens fed wheat/barley- or maize/soybean meal-based diets

1. A commercial enzyme preparation (Quatrazyme HP) containing xylanase and beta-glucanase was examined in two laying hen experiments with wheat/barley- or maize-based diets. The activities of other enzymes were measured also. Starch, cell wall contents and effects of Quatrazyme HP on in vitro viscosity of wheat, barley, maize and soybean meal were determined. 2. In the first experiment, 90 ISA Brown laying hens at 28 weeks of age were given a wheat/barley basal diet with or without 20mg of Quatrazyme HP, which provided 560 and 2,800 IU of xylanase and beta-glucanase/kg diet. In the second experiment, 66 ISA Brown laying hens at 45 weeks of age were given a maize/soybean meal basal diet with or without 20 mg of Quatrazyme HP/kg diet for 9 weeks. Egg production, egg weight, egg mass, feed conversion ratio and change in body weight were recorded as response criteria. 3. There was a significant improvement in feed conversion ratio with enzyme supplementation. Birds given an enzyme-supplemented diet gained 86 g while those fed on the unsupplemented diet lost 103 g of their body weight by the end of the experiment. 4. The enzyme preparation did not affect either egg production, egg weight or egg mass of birds fed on the maize/soybean meal diet. However, a significant improvement in feed conversion ratio was detected. Birds on either the supplemented or unsupplemented diet exhibited an increase in their body weight at the end of the experiment. 5. Addition of xylanase and beta-glucanase decreased in vitro viscosity of wheat, barley, maize and soybean meal. This effect was greater for wheat and barley than for maize and soybean meal. 6. It was concluded that the beneficial effect of using an enzyme preparation containing xylanase and beta-glucanase is not limited to wheat/barley-based diets but also occurs with maize/soybean meal-based diets.     

Effects of toxic and non‐toxic blue mussel meal on health and product quality of laying hens

Blue mussels (Mytilus edulis) are a potential protein source in poultry feeds because of their high methionine and cystein content. However, mussels may temporarily be contaminated with the toxin, okadaic acid. The aim of this small scale study was to evaluate the effects on animal health and morphology of the digestive tract of laying hens fed three different diets; a commercial feed and diets containing 15% normal or 15% toxic mussel meal, i.e. a concentration of 198.6 μg toxin per kg feed. Twelve laying hens were divided into six groups and fed the experimental diets for 8 weeks. Animal health, production performance and egg quality were recorded. At sacrifice, tissue samples were prepared for histological evaluation using light microscopy. Okadaic acid did not have any adverse effects on animal health or production parameters and no histological changes indicating disturbances in the digestive tract was observed. Internal egg quality was improved as eggs from hens fed either of the two mussel meal diets had an increased yolk colour. These results show that mussel meal functions as a novel protein source for laying hens and those toxic mussels at this level may be included in the feed without negative effects on parameters evaluated in this study.     

用杂粕代替部分豆粕配制日粮对蛋种鸡生产性能及蛋品质的影响

试验研究了氨基酸平衡的低蛋白质和杂粕日粮对蛋种鸡产蛋性能和蛋品质的影响,结果表明:当棉籽粕、菜籽粕、棉菜粕分别代替5.5%、5%、10%的豆粕时,对蛋鸡产蛋率、日产蛋重和料蛋比无显著影响,也不影响蛋的品质(P>0.05),同时每产1kg蛋消耗的饲料成本玉米-棉粕和玉米-棉菜粕组,显著低于对照组(P<0.05);但当日粮粗蛋白质水平降低2个百分点时,蛋种鸡的日平均产蛋重显著低于正常蛋白质水平的玉米-豆粕日粮(P<0.05),而与正常蛋白质水平的杂粕日粮相比,差异不显著(P>0.05)。     

Supplemental defatted microalgae affects egg and tissue fatty acid composition differently in laying hens fed diets containing corn and flaxseed oil

Effects of defatted microalgae (DFA) on fatty acid composition of eggs and tissues of hens have not been well studied. This experiment was to determine how low concentrations of supplemental DFA in the presence or absence of flaxseed oil (FO) altered fatty acid profiles of egg yolk, liver, adipose tissue, and plasma of layers. A total of 60 Shaver Leghorn layer hens (individually caged, 20-wk old) were allotted into 6 groups (n = 10) and fed a corn/soybean meal basal diet containing 0, 3, or 5% DFA and 0 (1.5% corn oil, CO) or 1.5% FO for 6 wk. BW, ADFI, egg production rate, and egg component weights were not affected by any of the dietary treatments at various time points, but egg yolk color was changed (P < 0.05) with increasing concentrations of DFA. The concentration of n-3 fatty acids in egg yolk and plasma were elevated by FO up to 9-fold (P < 0.05) starting at wk 1 or 2, and 39 to 83% (P < 0.05) by DFA. Supplemental DFA improved (P < 0.05) n-6/n-3 fatty acid ratios in egg yolk and plasma from 13 to 23 and 7 to 13, respectively, only in hens fed diets without FO. Fatty acid profiles of liver and adipose tissue (at wk 6) displayed responses to supplemental DFA and FO similar to those of egg yolk or plasma. In conclusion, supplemental 3 or 5% DFA caused moderate enrichments of n-3 fatty acids and decreased the n6/n3 fatty acid ratios of egg yolk and tissues in hens fed diets without FO.     

不同饲粮粗蛋白质水平下黑水虻蛋白替代豆粕对蛋鸡生产性能、蛋清品质及血清蛋白质代谢指标的影响

本试验旨在探讨不同饲粮粗蛋白质水平下黑水虻蛋白替代豆粕对蛋鸡生产性能、蛋清品质及血清蛋白质代谢指标的影响。采用单因素随机试验设计,选用252只产蛋率相近的33周龄罗曼白蛋鸡,随机分为3组,每组7个重复,每重复12只鸡。各组分别饲喂标准回肠可消化氨基酸(SIDAA)平衡模式下配制的不同粗蛋白质水平(16.50%、14.85%、13.20%)的玉米-豆粕-黑水虻蛋白饲粮,各组黑水虻蛋白与豆粕提供等量的粗蛋白质。预试期2周,正试期12周。结果表明:1)与16.50%组相比,14.85组%和13.20%组的产蛋率和平均日采食量无显著影响(P>0.05),平均蛋重显著降低(P<0.05),料蛋比显著升高(P<0.05);13.20%组的产蛋量显著降低(P<0.05),14.85%组的产蛋量无显著差异(P>0.05)。2)与16.50%组相比,14.85%组的平均蛋重、蛋清重、浓蛋白重、蛋白高度、哈氏单位和蛋清比例均无显著差异(P>0.05);13.20%组的平均蛋重、浓蛋白重、蛋白高度显著降低(P<0.05),蛋清重和哈氏单位呈下降趋势(P=0.0513和P=0.0673)。3)各组血清谷草转氨酶、谷丙转氨酶活性及总蛋白、白蛋白、尿酸含量无显著差异(P>0.05)。16.50%和13.20%饲粮粗蛋白质水平对蛋鸡输卵管膨大部分泌功能有轻微不良影响。由此可见,在SIDAA模式下,以黑水虻蛋白替代豆粕并使饲粮粗蛋白质水平降低至14.85%时对鸡蛋蛋清品质无不良影响。