Effect of excess dietary threonine on laying performance,egg quality,serum free amino acids,and digestive enzymes activities of laying hens during the postpeak period

A total of 640 layer hens, 56 wk of age, were allocated to 4 dietary treatments groups, each of which included 5 replicates of 32 hens. Graded levels ofl-Thr were added to the basal diet at 0.0 (control), 1.0, 2.0, and 3.0 g/kg; determined Thr values were 5.7, 6.5, 7.4, and 8.7 g/kg of diet, respectively. In the 53-d feeding trial, egg production increased significantly due to dietaryl-Thr supplementation. Hens fed 2.0 g of Thr/kg of diet had significantly higher egg production than the control diet. Supplementing the diet withl-Thr did not affect egg weight or feed intake, but egg mass increased significantly. Also, FCR was improved significantly and the best FCR was exhibited by hens receiving 2.0 g of Thr/kg of diet. Feeding laying hens a diet containing 2.0 g ofl-Thr/kg of diet improved Haugh units linearly; however, egg shell thickness decreased linearly as the level of dietary Thr increased, and the lowest value was observed for hens fed 3.0 g of Thr/kg of diet. Serum free Thr increased linearly as supplemental Thr increased, but serum free Ile, Phe, and Tyr decreased. No differences attributable tol-Thr were found among groups in the activity of digestive enzymes (trypsin and amylase) in the mucosal homogenates of the jejunum. The activity of α-alkaline phosphatase in the jejunum was analyzed as a marker of mucosal enterocyte maturation and no differences due tol-Thr supplementation were noted. In conclusion, feeding laying hens from 56 to 64 wk of agel-Thr up to 2.0 g/kg can improve laying performance and Haugh units.     

人参提取物对蛋鸡产蛋性能、蛋品质、血清生化指标及经济效益的影响

文章旨在评估日粮添加不同水平人参提取物对蛋鸡产蛋性能、蛋品质及血清生化指标的影响。试验选择产蛋性能一致的450只海兰褐壳蛋鸡,随机分为3组,每组5个重复,每个重复30只。对照组饲喂基础日粮,处理组分别在基础日粮中添加0.04%和0.08%人参提取物,试验共进行6周。结果：与对照组相比,0.04%和0.08%人参提取物组产蛋率分别显著提高10.21%和8.77%（P＜0.05）,平均蛋重分别显著提高11.68%和9.07%（P＜0.05）。0.04%人参提取物组料蛋比较对照组显著降低6.51%（P＜0.05）,蛋壳颜色较对照组显著提高26.50%（P＜0.05）。对照组血清胆固醇浓度较处理组分别显著提高52.02%和58.32%（P＜0.05）。0.04%人参提取物组血清超氧化物歧化酶活性较对照组显著提高30.50%（P＜0.05）。0.04%和0.08%人参提取物组血清IgG和IgM浓度较对照组分别显著提高53.47%、60.72%和36.44%、42.43%（P＜0.05）。与对照组相比,0.04%和0.08%人参提取物组盲肠乳酸杆菌含量分别显著提高15.13%和12.82%（P＜0.05）。结论：在本试验条件下,日粮添加0.4?g/kg人参提取物可以提高蛋鸡饲料效率和蛋壳颜色。 [关键词]人参提取物|蛋鸡|产蛋性能|蛋品质|血清生化     

复合微生态制剂对蛋鸡产蛋性能、蛋品质、血清生化指标和肠道形态的影响

试验在基础饲粮中添加由丁酸梭菌和屎肠球菌组成的复合微生态制剂,研究其对产蛋高峰期蛋鸡的产蛋性能、蛋品质、血清生化指标、肠道形态的影响.选取产蛋率和体重接近的40周龄健康的海兰褐蛋鸡400只,随机分成4组,每组5个重复,每个重复20只鸡.对照组蛋鸡饲喂基础饲粮,抗生素组在基础饲粮中添加200 g/t金霉素,试验1组、2组...     

有机源锌和锰对蛋鸡生产性能、蛋壳和骨质量的影响

文章旨在研究日粮添加有机源锌和锰替代无机锌和无机锰对蛋鸡生产性能、蛋壳和骨骼质量的影响。试验选择31周龄产蛋性能接近的罗曼粉壳蛋鸡616只,随机分为7组,每组4个重复,每个重复22只。基础日粮锌和锰含量分别为50和30 mg/kg,对照组饲喂基础日粮,分别添加氧化锌和硫酸锰(锌40 mg/kg,锰60 mg/kg)。处理组分别在基础日粮中添加20 mg/kg有机锌,30 mg/kg有机锰、20 mg/kg有机锌+30 mg/kg有机锰、40 mg/kg有机锌、60 mg/kg有机锰、40 mg/kg有机锌+60 mg/kg有机锰,上述含量均以相应元素计。试验共进行7周。结果显示:日粮用有机锌或锰替代50%或100%无机锌、锰对蛋鸡生产性能相关参数均无显著影响(P> 0.05)。对照组相比,有机锌或锰替代无机锌或锰的比例对32、46、60和74周龄蛋鸡蛋壳相对重量、蛋壳密度和蛋壳厚度均无显著影响(P> 0.05)。与对照组相比,30 mg/kg有机锰、20 mg/kg有机锌+30 mg/kg有机锰组的蛋壳强度显著提高(P <0.05)。40 mg/kg有机锌+60 mg/kg有机锰组较无机锌、锰组显著提高了60、74周龄及全期蛋壳强度(P <0.05)。日粮添加有机锌或锰对胫骨物理参数及胫骨和趾骨灰分含量均无显著影响。结论 :日粮添加有机锌、锰替代无机锌锰对蛋鸡产蛋性能和骨质量无影响,但可以降低蛋鸡由于年龄升高对蛋壳强度的负面影响。     

海藻饲料添加剂对蛋鸡产蛋性能、血清抗氧化性及生长的影响

试验研究了在蛋鸡饲粮中添加不同剂量的海藻饲料添加剂对蛋鸡产蛋性能、血清抗氧化性、生长及营养物质消化率等的影响。选取360只26周龄体重相近的海兰褐蛋鸡,随机分为6组(每组3个重复,每个重复20只鸡),1组为空白对照组,饲喂基础饲粮;2组为抗生素对照组,在基础饲粮中添加0.005%的杆菌肽锌;3~6组为试验组,分别在基础饲粮中添加0.02%、0.04%、0.06%、0.08%的菊粉,0.025%、0.050%、0.100%、0.150%的大西洋海藻粉及相同剂量的铜藻粉(以下简称低、中、较高、高剂量海藻复合物),预试期7 d,正式试验期63 d。结果表明:海藻饲料添加剂对蛋鸡的产蛋性能有明显的剂量-效应关系,添加量为中等剂量海藻复合物(4组)时最佳且差异显著(P<0.05)。此添加量下,蛋鸡血清中超氧化物歧化酶活性最高(P<0.05)。试验中粗纤维的表观消化率随添加剂量的增加而增加(P<0.05)。低剂量试验组体重增长最多且差异显著(P<0.05)。试验结果表明,基础饲粮中添加中剂量海藻复合物作为蛋鸡饲料添加剂,能够显著提升蛋鸡产蛋性能及血清抗氧化性。     

Effect of expanded cottonseed meal on laying performance,egg quality,concentrations of free gossypol in tissue,serum and egg of laying hens

Three hundred and sixty Hy‐Line Brown hens, 40 week of age, were allocated to five treatments, each of which included four replicates of 18 hens. After an expanded process of cottonseed meal (CSM), free gossypol content in CSM was decreased from 1.24 to 0.40 g/kg. The dietary treatments were corn‐soybean meal based diets including 6% CSM and 6%, 8% and 10% expanded cottonseed meal (ECSM). Hens fed 8% ECSM had higher (P < 0.05) laying rate and average egg weight than those fed 6% CSM. The albumen height and Haugh unit in the control group, 6% and 8% ECSM groups were superior (P < 0.05) to other treatments. Hens fed 6% CSM resulted in severe (P < 0.05) egg yolk discoloration. Free gossypol (FG) concentrations in yolk and albumen and tissues of the 6% CSM group were greater (P < 0.05) than those in any ECSM treatments. Hens fed 6% CSM and 10% ECSM had the highest (P < 0.05) FG concentrations in the liver compared with those in the kidney and muscle, and higher (P < 0.05) FG residues in yolk than those in albumen. In conclusion, FG in CSM can be reduced by 68% through an expanded process and ECSM can be available in laying hens at up to 10% of the total diet and an appropriate replacement of soybean meal with ECSM may improve performance in laying hens.     

Effects of iron glycine chelate on laying performance,antioxidant activities,serum biochemical indices,iron concentrations and transferrin mRNA expression in laying hens

This study was conducted to evaluate the effects of iron glycine chelate (Fe‐Gly) on laying performance, antioxidant enzyme activities, serum biochemical indices and iron concentrations in laying hens. A total of 810 laying hens (Hy‐Line Variety White, 26 weeks old) were randomly assigned to six groups with five replicates of 27 layers. Hens in the control group received diet supplemented with 60 mg Fe/kg as FeSO₄, while hens in other five groups received the diet supplemented with 0, 20, 40, 60 and 80 mg Fe/kg from Fe‐Gly respectively. The results showed that dietary Fe‐Gly treatments significantly influenced (p < 0.01) the laying rate and egg weight of layers, compared with the control group. Concerning to CuZn‐superoxide dismutase (CuZn‐SOD) and total superoxide dismutase (T‐SOD) activity, Fe‐Gly groups (60, 80 mg Fe/kg) were promoted significantly (p < 0.01) compared with 0 mg Fe/kg group. The concentrations of Fe in serum, liver, kidney, spleen and ovary were increased significantly with the level dietary Fe‐Gly raised where Fe‐Gly groups (60, 80 mg Fe/kg) had observably higher Fe concentration than the control (p < 0.01) in serum, kidney and spleen. There was a trend that transferrin mRNA expression was decreased with the increase of Fe as Fe‐Gly in diets, and compared with the control, the expression was lower in the group fed diet with 60 mg/kg Fe as Fe‐Gly. In conclusion, Fe‐Gly (60 mg Fe/kg) had improved laying rate, egg weight, SOD enzyme activity, Fe absorption and protein synthesis in body and promoted iron metabolism in laying hens. Moreover, Fe‐Gly (40 mg/kg Fe) had the similar effect with control group. It revealed that FeSO₄ could be substituted by lower concentration of Fe‐Gly and Fe‐Gly may be superior to FeSO₄ for iron fortification to laying hens.     

维生素E对蛋鸡产蛋后期产蛋性能和蛋品质的影响

文章旨在研究日粮中不同梯度维生素E添加水平对蛋鸡产蛋后期产蛋性能和蛋品质的影响.试验选择60周龄罗曼白壳商品蛋鸡300羽,试验随机分为5组,添加水平分别为0(对照组),30、60、120、240 mg/kg,每组6个重复,每个重复10羽鸡,预试期1周,正试期8周.结果表明:与对照组相比,蛋鸡产蛋后期日粮中添加120 m...     

日粮中长期添加大豆黄酮对产蛋鸡产蛋性能及有关内分泌的影响

试验旨在探讨日粮中长期添加大豆黄酮对产蛋高峰期蛋鸡采食和生产性能的影响及有关内分泌机制。40羽180日龄产蛋鸡,均分为2组,对照组饲喂基础日粮,试验组饲喂基础日粮+大豆黄酮(6mg/kg),试验期为150d。结果显示:试验组蛋鸡采食量、产蛋率、只日蛋重、每枚蛋重均显著提高,料蛋比显著下降;血清17β-雌二醇、T3、T4水平均显著提高,而血清瘦素(leptin)水平有下降的趋势。试验结果表明,大豆黄酮可调控血液激素水平而提高产蛋鸡生产性能,并使产蛋高峰期得到延长。     

不同硒源对蛋鸡生产性能和硒沉积的影响

文章旨在研究日粮添加不同硒源及不同水平对蛋鸡生产性能和鸡蛋中硒沉积量的影响。试验选择产蛋率一致的海兰褐壳蛋鸡720只,随机分为5组,每组6个重复,每个重复24只鸡。试验共设计5种日粮,对照组饲喂基础日粮(不添加硒),处理组分别在基础日粮中添加2个水平的无机硒(0.4和0.8mg/kg硒,亚硒酸钠)以及2个水平的酵母硒(0.4和0.8mg/kg硒),试验共进行16周。结果发现,无论日粮添加酵母硒还是无机硒,随着硒添加水平的升高,蛋鸡生产性能均无显著影响(P>0.05)。从第9周到试验结束,0.4mg/kg无机硒和0.8mg/kg酵母硒组较对照组和0.8mg/kg无机硒组显著提高了蛋鸡的产蛋率(P<0.05)。试验第9周开始,对照组、0.8mg/kg无机硒组和0.4mg/kg酵母硒组产蛋率显著降低(P<0.05)。随着日粮无机硒或酵母硒添加水平的升高,鸡蛋中硒的沉积量显著线性增加(P<0.05)。从第4周开始到试验结束,无机硒或酵母硒组较对照组均显著提高了鸡蛋中硒含量(P<0.05)。在同一硒添加水平及同一时间下,酵母硒较无机硒显著提高了鸡蛋硒含量(P<0.05),随着试验时间的增加,对照组鸡蛋硒含量显著降低(P<0.05)。因此,在本试验条件下,日粮硒的来源和添加水平直接影响鸡蛋硒沉积量,酵母硒较无机硒显著提高了鸡蛋硒沉积量。日粮中酵母硒的添加量可以达到0.8mg/kg,对蛋鸡生产性能无负面影响。     

Effect of yeast with bacteriocin from rumen bacteria on laying performance,blood biochemistry,faecal microbiota and egg quality of laying hens

The purpose of this study was to evaluate the effect of yeast with bacteriocin from Ruminococcus albus 7 (albusin B) on physiological state and production performance of laying hens. One hundred and twenty 26‐week‐old Single Comb White Leghorn (Hyline) laying hens were assigned into five groups including: (i) control group, (ii) yeast control (YC), (iii) 0.125% yeast with bacteriocin (0.125B), (iv) 0.25% yeast with bacteriocin (0.25B) and (v) 0.5% yeast with bacteriocin (0.5B). All supplements were added to the experimental diets of the hens from 26 to 46 weeks of age. Samples were collected every 4 weeks. Blood samples were collected from the wing vein for blood biochemical parameters assay, and faecal samples were collected by swab for the microbiota test. The egg production performance was recorded daily, and fresh eggs were collected for quality test. The blood biochemical assay results indicated that the addition of yeast with bacteriocin decreased the AST (aspartate aminotransferase) activity and it also affects the lactate concentration in laying hen blood. The result of egg quality indicated that yeast with bacteriocin supplementation had no effect on the mass of yolk and the strength of eggshell, but it had positive effect on the laying performance under hot environment. Low concentration bacteriocin (0.125B) supplementation could decrease total yolk cholesterol. The faecal microbiota result indicated that the supplementation of bacteriocin increased the lactobacilli counts. The yeast with bacteriocin supplementation significantly decreased the clostridia counts under hot environment condition, especially in hens receiving 0.25B. Combining the data from clinic chemistry, faecal microbiota, egg production and egg quality, the 0.25B supplementation may result in the best physiological parameter and egg production performance of laying hen.     

复合型抗应激添加剂对夏季蛋鸡产蛋性能、蛋品质及血清生化指标的影响

为了研究复合型抗应激添加剂对夏季蛋鸡产蛋性能、蛋品质及血清生化指标的影响,试验选用120只42周龄伊莎褐蛋鸡,随机分为2组,每组设6个重复,每个重复lO只;对照组饲喂基础日粮,试验组饲喂基础日粮＋80mg／kg复合型抗应激添加剂——禽专用添佳安肽,试验期为60d。结果表明：与对照组相比,试验组产蛋率显著提高5．56％（P〈0．05）,料蛋比显著降低4．74％（P〈0．05）,但对采食量和平均蛋重无显著影响（P〉0．05）;试验组蛋壳强度显著提高15．27％（P〈O．05）,但对蛋壳厚度、蛋白高度、哈夫单位无显著影响（P〉0．05）;试验组血清皮质醇水平显著下降53．91％（P〈0．05）,T_3、T_4水平分别显著下降20．12％、23．57％（P〈0．05）,尿素氮水平显著下降35．35％（P〈0．05）,但对血糖水平无显著影响（P〉0．05）。说明蛋鸡日粮中添加复合型抗应激添加剂——禽专用添佳安肽,具有显著抗热应激效应和增加蛋鸡采食量的作用。     

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.     

Effects of dietary Lactobacillus acidophilus and Bacillus subtilis on laying performance,egg quality,blood biochemistry and immune response of organic laying hens

The objective of this study was to evaluate the effects of two different probiotic micro‐organisms on the performance, egg quality and blood parameters of organically reared hens. A total of 900 16‐week‐old Hy‐Line layer hybrids were randomly assigned to three groups of 300 birds each. The control (CTR) group was fed a corn–soya bean cake‐based diet; the L group was fed the same diet supplemented with 0.1% Lactobacillus acidophilus, while the B group was fed the same diet supplemented with 0.05% Bacillus subtilis. Data were recorded at the beginning (weeks 5 and 6: T1) and at the end (weeks 19 and 20: T2) of the experiment, and no differences in hen performance were recorded between dietary groups or sampling times. All of the investigated clinical chemistry parameters, except GGT, were affected by diet (p < 0.05), with the best results recorded for the probiotic‐treated groups. The immune‐response values showed higher blood bactericidal activity in the B and L groups at T2 (p < 0.05) and a lower lysozime concentration in the B group at T1. Higher antibody production against Newcastle disease virus was observed in the L group compared to the CTR (p = 0.013). No differences in oxidative status were recorded, and no effects of diet on egg quality were observed. Among the physical egg characteristics, only the Roche scale colour was affected by diet (p < 0.05): the egg yolk was paler in the L group. The age of the hen was the most relevant factor affecting physical egg characteristics. The chemical parameters of the egg were almost unaffected by supplementation with probiotics except for the lipid content, which decreased with the L diet (p < 0.05). Both probiotic inclusions had beneficial effects on hen metabolism and welfare, and L. acidophilus induced the best immune response.     

蛋鸡产蛋后期的营养调控

蛋鸡产蛋后期精准的营养调控可延缓蛋鸡的衰老,延长产蛋期,提高经济效益。本文从能量、蛋白质、维生素、矿物元素的营养需要等方面对蛋鸡产蛋后期的营养调控进行总结,以期能够对产蛋鸡后期的营养调控提供参考。 [关键词] 产蛋后期|营养|蛋壳质量|产蛋率     

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...     

Effect of dietary supplementation of organic zinc on laying performance,egg quality and some biochemical parameters of laying hens

This study was conducted to evaluate the effects of zinc methionine (Zn‐Met) supplementation on the performance, egg quality, antioxidant status and some biochemical parameters of blood serum in laying hens from 22 to 34 weeks of age. A total of 120 Hisex Brown laying hens of 22‐week‐old were randomly allocated into five treatments with six cage replicates for each (four hens/replicate). Dietary treatments consisted of the basal diet with no Zn‐Met supplementation (control group) and basal diet supplemented with 25, 50, 75 or 100 mg Zn‐Met/kg diet. No significant differences were observed on body weight, body weight gain or feed conversion ratio due to dietary Zn‐Met supplementation. However, highly significant impact was observed on daily feed intake. Egg number, egg weight and egg mass were increased in the group fed diet supplemented with the highest level of Zn‐Met (100 mg/kg of diet) as compared to other groups. All egg quality traits were statistically (p > .05 or .01) affected as a response to dietary Zn‐Met supplementation except egg shape index, shell percentage and yolk index. In comparison with the control group, dietary supplementation of 25, 50, 75 or 100 mg Zn‐Met/kg decreased serum triglyceride and LDL‐cholesterol levels. Serum cholesterol level was increased with all dietary levels of Zn‐Met in comparison with the control group. Dietary Zn‐Met supplementation increased the serum content of zinc, where the highest values were recorded with 50 and 100 mg Zn‐Met/kg diet. Dietary Zn‐Met levels did not affect the antioxidant indices in blood serum except for the activity of copper–zinc superoxide dismutase (Cu‐Zn‐SOD). The activity of Cu‐Zn‐SOD was increased with Zn‐Met supplementations with no differences among supplemental zinc levels. It is concluded that dietary Zn‐Met supplementation reduced serum triglyceride, LDL‐cholesterol and increased Zn status and resulted in promoting antioxidant ability of laying hens, and the addition of 100 mg Zn‐Met/kg to layer diet was appropriate for improving the above parameters in addition to egg production indices and Haugh unit score.