Performance and economic evaluation of feeding programs varying in energy and protein densities for broiler grillers

A study was conducted to evaluate field performance and economic impacts of feeding diets varying in AME and amino acid (AA) densities to Cobb 500 female broiler grillers (eviscerated carcass averaging 1.0 kg). Corn–soy diets were fed to birds in a factorial arrangement of 3 AME (low, moderate, and high) by 3 AA densities (low, moderate, and high). Differences in AA and AME average values were of 10 and 1.5%, respectively. Treatments had 8 replications of 40 birds allocated in floor pens. Live performance was significantly improved in parallel with increases in AME and AA; however, carcass yield increased and abdominal fat was reduced only when AA was increased (P < 0.05). Gross margins (GM) for each treatment were calculated using scenarios of high and low market costs for corn, soybean meal, as well as for carcass prices. Costs were classified as variable [costs of feeding (CF), fixed farm costs (FFC), and fixed processing costs (FPC)] and their behavior in response to nutritional density was studied. All cost components, (CF, FFC, and FPC) decreased as AME increased, which resulted in the lowest total costs (TC) for the highest AME diets in all scenarios tested, as well as the greatest GM for those dietary programs. In contrast to AME, cost components moved in opposite directions in response to AA density whereby, in 4 out of 7 scenarios, optimizing CF did not result in greater GM. The present study was conducted with low-weight carcasses and, therefore, conclusions made from the presented data are restricted to this type of product. It is concluded that when broiler grillers are objects of study, the use of CF as the sole criteria to choose an optimal feeding program, without considering significant fixed costs present along the production and meat processing chains, tends to underestimate the economic potential of increasing nutrient density.     

全株玉米青贮营养品质的紧实度效应

本研究旨在分析不同紧实度对全株玉米(Zea mays)青贮品质变化的影响,以便筛选出适宜的青贮紧实度。以新饲玉10号青贮玉米为材料,青贮装料密度设计为5个(350、400、500、600、700kg·m-3),分别在青贮制作完成后1、3、5、7、9、15、30、50d取样,测定青贮料的干物质(DM)、粗蛋白(CP)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、水溶性碳水化合物(WSC)和pH,并动态监测开窖后各处理青贮内部温度变化规律,同时对比开窖前后的相对饲喂价值(RFV)。结果表明,青贮时间和紧实度的交互作用仅对CP、ADF和pH有极显著影响(P0.01),对DM、NDF和WSC均无显著影响(P0.05)。处理600kg·m-3的pH最低且CP含量最高;处理700kg·m-3的DM、WSC以及RFV值含量最高,NDF及ADF含量最低。处理600kg·m-3有氧暴露后稳定的时间显著高于其它处理(P0.05),达到100h。同时,有氧暴露时间与温度呈现出单调递增的趋势,且相关性显著(P0.05)。随着紧实度的增大(350~600kg·m-3),青贮饲料的品质增加,有氧稳定性提高;当紧实度为600kg·m-3时,品质较700kg·m-3变化不显著,600kg·m-3为最佳紧实度,建议采用。     

野生和养殖红鳍东方鲀营养品质的比较分析

本试验对野生1龄、养殖1龄和养殖2龄红鳍东方鲀的一般营养成分及肌肉氨基酸和脂肪酸的组成进行测定,旨在比较野生和养殖红鳍东方鲀的营养品质。试验选取野生1龄红鳍东方鲀15尾(体重71~139 g、体长13.4~18.9 cm)、养殖1龄红鳍东方鲀(投喂冰鲜杂鱼)13尾(体重90~147 g、体长14.8~20.4 cm)、养殖2龄红鳍东方鲀(投喂冰鲜杂鱼)10尾(体重578~639 g、体长31.3~36.7 cm)作为样本。采用国家标准方法测定组织中的一般营养成分及肌肉氨基酸和脂肪酸组成,并对肌肉营养品质进行分析。结果表明:全鱼粗蛋白质含量以野生1龄红鳍东方鲀最高,为68.07%,比养殖1龄和养殖2龄红鳍东方鲀分别高出了32.3%、20.6%(P0.05),而全鱼粗脂肪含量则为养殖1龄和养殖2龄红鳍东方鲀显著高于野生1龄红鳍东方鲀(P0.05);养殖2龄红鳍东方鲀肌肉粗蛋白质含量显著高于野生1龄和养殖1龄红鳍东方鲀(P0.05),各样本间肌肉粗脂肪和粗灰分含量差异不显著(P0.05);各样本的肝脏粗蛋白质和粗脂肪含量变化较大,粗蛋白质含量按照野生1龄、养殖1龄、养殖2龄的顺序依次显著降低(P0.05),而粗脂肪含量则呈现与粗蛋白质相反的变化。野生和养殖红鳍东方鲀肌肉中均检测出18种氨基酸,而且在含量上养殖红鳍东方鲀大多数均显著高于野生红鳍东方鲀(P0.05)。根据氨基酸评分(ASS)和化学评分(CS),红鳍东方鲀肌肉中赖氨酸的含量相对较为丰富,且养殖2龄红鳍东方鲀必需氨基酸指数(EAAI)最高,其次为养殖1龄红鳍东方鲀,最后为野生1龄红鳍东方鲀。野生和养殖红鳍东方鲀肌肉中共检测出19种脂肪酸,且野生和养殖红鳍东方鲀脂肪酸组成相似,野生1龄、养殖1龄和养殖2龄红鳍东方鲀肌肉中饱和脂肪酸(SFA)含量差异不大(P0.05),多不饱和脂肪酸(PUFA)含量则以养殖2龄红鳍东方鲀最高,为51.54%,但是各样本间差异不显著(P0.05);肌肉中C20∶5n-3(EPA)和C22∶6n-3(DHA)含量均较丰富,其中养殖1龄和养殖2龄红鳍东方鲀DHA的含量分别比野生1龄红鳍东方鲀高出了24.7%、27.2%(P0.05),而且养殖1龄和养殖2龄红鳍东方鲀EPA+DHA的含量也显著高于野生1龄红鳍东方鲀(P0.05)。由此可知,红鳍东方鲀营养组成合理,且养殖红鳍东方鲀营养品质优于野生红鳍东方鲀。     

内蒙古青贮饲料质量研究

为探讨内蒙古青贮饲料品质现状,采用抽样方法对内蒙古青贮饲料质量进行研究。结果表明,内蒙古青贮设备主要以窖贮和壕贮为主,青贮时间一般为9和10月,青贮种类主要有全株玉米青贮、玉米秸青贮、甜菜类青贮等;青贮饲料发酵品质总体表现较好,通过对青贮饲料有机酸进行费氏评分,达到优良等级的占总样品的83%,全株玉米青贮和甜菜类青贮经费氏评分均达到优等,但是,全株玉米青贮饲料中的乳酸含量显著高于甜菜类青贮饲料(P＜0.05),乙酸和丁酸含量均显著低于甜菜类青贮饲料(P＜0.05),玉米秸青贮饲料费氏评分为良,内蒙古青贮饲料有机酸费氏评定结果与感官评定结果基本相符;3种青贮饲料中,甜菜类青贮饲料的营养品质最好,全株玉米青贮饲料次之,玉米秸青贮饲料最劣。综合分析结果表明,内蒙古全株玉米青贮饲料和甜菜类青贮饲料营养保存率高,发酵效果好,玉米秸青贮饲料质量较差。     

青贮时间对巨型稻秸秆青贮发酵感官评分与营养品质的影响

试验旨在研究青贮时间对巨型稻秸秆青贮发酵感官评分与营养品质的影响,确定适宜的青贮发酵时间.试验测定3个不同青贮时间(7、14、28 d)巨型稻秸秆的感官评分以及营养品质.结果 表明,青贮时间为7d时,巨型稻秸秆含水量约50％,青贮品质评分最高,评定为优等;此时,青贮料的粗蛋白含量达到最高,为6.83％,粗脂肪、灰分、粗...     

Effect of amino acid deficiency on precaecal amino acid digestibility in broiler chickens

In this study, we determined whether deficient dietary amino acid (AA) concentrations influence the precaecal (pc) AA digestibility when determined using the regression approach. We mixed two basal diets. Basal diet 1 was deficient in essential AAs, whereas adequate AA concentrations were ensured in basal diet 2 by adding free AAs. Rapeseed cake and full‐fat soya beans as test ingredients were included in the basal diets at levels of 100 and 200, and 150 and 300 g/kg, respectively, at the expense of maize starch. Each diet was tested with six replicates of 10 broiler chickens each. The feed intake of the chickens that were fed diets based on basal diet 2 was similar, whereas the feed intake of the chickens that were fed diets based on basal diet 1 differed considerably. The numerical differences in pc AA digestibility determined with basal diet 1 or 2 ranged from 2.6 percentage points to 20.8 percentage points in rapeseed cake and from 0.5 percentage points to 15.2 percentage points in soya beans. Across all measured AAs, the average differences were 10.1 percentage points and 5.4 percentage points in rapeseed cake and soya beans, respectively. The differences in the estimated pc AA digestibility between the basal diets were probably caused by different basal endogenous AA losses in the digesta between treatments as a consequence of different feed intake. Adequate AA concentrations and test ingredient levels that are specifically adjusted to avoid a negative effect on feed intake are recommended for future studies.     

带穗玉米静贮与玉米秸秆青贮饲养育成牛的试验

为了证实带穗玉米青贮饲养育成奶牛的效果，采样分析了带穗玉米青贮和玉米秸秆青贮的营养成分，并且以２６头６～９月龄的荷坦育成牛进行了４０ｄ的配对饲养试验。结果表明：带穗玉米青贮的粗蛋白质和磷含量均高于玉米秸秆青贮。饲喂带穗玉米青贮的试验组牛的日粮营养平衡情况优于饲喂玉米秸秆青贮的对照组牛，试验组牛和对照组的日增重分别为１１９２．５和９９５．０ｇ，日增重水平提高１９．８５％，增重效益提高２１．０２％。．     

甜菜碱替代部分蛋氨酸喂肉鸡的试验

本试验检验了在肉仔鸡日粮中用甜菜碱替代部分蛋氨酸对增重及饲料转化率的影响。试验选用"AA"肉仔鸡1480只,试验组780只,分为6个重复,每个重复130只。对照组700只分为5个重复。每个重复140只,试验组用山东曲阜圣旺制药有限公司生产的无水甜菜碱,纯品≥97％。试验结果表明:前期(0-21日龄)日增重和体重在各处理组之间无显著差异(P>0.05)。中期(22-35日龄)试验组日增重和体重好于对照组(P<0.05)。后期(36-49日龄)试验组日增重较对照组差(P<0.05),整个试验期试验组肉仔鸡的成活率比对照组高出5.859个百分点。     

饲用高粱青贮的饲喂价值和经济效益分析

高粱生物产量高、抗逆和适应性强,将其制作成青贮饲料,干物质产量、蛋白质含量、有氧稳定性高.草食家畜养殖是节粮型畜牧业的代表.采用高粱青贮饲喂草食家畜,不仅可以提高生产性能、增强免疫力、改善胴体品质,而且可以缓解冬季青贮饲料资源缺乏的问题,提高经济效益.为促进草食家畜养殖业健康稳定发展,文章对饲用高粱青贮的饲喂价值和经济...     

不同赖氨酸源对规模化饲养肉鸡生产性能的影响

试验研究了不同赖氨酸源(65%赖氨酸硫酸盐和98.5%赖氨酸盐酸盐)对肉鸡生产性能的影响,探讨国产赖氨酸硫酸盐在肉鸡饲料中实际应用的可行性。试验结果表明:整个试验期不同处理组对矮脚黄A公鸡的生产性能影响差别不大,而在综合经济效益分析上,用国产赖氨酸硫酸盐组要好于进口赖氨酸盐酸盐组,所需的增重成本较低,毛利较高,赖氨酸硫酸盐能够替代赖氨酸盐酸盐用于肉鸡饲料中。建议在大型养鸡场中推广应用,以更好地节省成本,提高经济效益。     

Effect of low-temperature drying on the nitrogenous compounds and inositol phosphates in broiler chickens and cecectomized laying hen excreta

We investigated how the chemical composition of broiler chicken and cecectomized laying hen excreta is affected by drying in a forced-air drying chamber at low temperatures. Excreta that was immediately frozen after voiding provided the reference values. The excreta were dried in drying chambers for 4 hr, 6 hr, and 12 hr at 23°C or 33°C in the broiler experiment and 19°C or 29°C in the cecectomized laying hen experiment. The total N and inositol phosphate concentrations in the excreta of broiler chickens and cecectomized laying hens were not influenced (p > .050), except for one inositol tetrakisphosphate isomer (p = .026) in broilers. Compared to fresh excreta, drying did not affect the ammonia concentrations in the cecectomized laying hen experiment (p > .050), but the ammonia concentration was lower when dried for 12 hr at 33°C in the broiler experiment (p = .002). Amino acid concentrations in cecectomized laying hen excreta decreased until 4 hr of drying and then increased at both drying temperatures (p < .001). The results indicate that the applicability of drying poultry excreta at low temperatures in forced-air drying chambers to determine the chemical compound concentrations is trait-dependent. Future studies are necessary to investigate whether these results are also dependent upon the amount of excreta stored in the drying chambers.     

5种光色环境对欧洲舌齿鲈营养品质的影响

为了解不同光色(全光谱光、蓝光、绿光、黄光、红光)环境对欧洲舌齿鲈(Dicentrarchus labrax)营养品质的影响,对欧洲舌齿鲈幼鱼[体质量为(29. 91±0. 39) g、体长为(13. 78±0.35) cm)]在不同光色环境下进行为期50 d的养殖试验。试验设全光谱光组、蓝色组、绿色组、黄色组、红色组,每组设置4个重复,每个重复30尾欧洲舌齿鲈幼鱼。采用国家标准方法对各组欧洲舌齿鲈全鱼和肌肉常规营养成分含量以及肌肉氨基酸与脂肪酸组成进行测定,并对肌肉营养品质进行分析。结果表明:1)绿光组全鱼及肌肉的粗脂肪含量均显著高于其他4组(P<0.05),但各组全鱼及肌肉水分、粗蛋白质、粗灰分含量均差异不显著(P>0.05)。2) 5种光色环境下欧洲舌齿鲈肌肉中均检测到18种氨基酸,其中绿光组7种氨基酸(天冬氨酸、谷氨酸、甘氨酸、丙氨酸、苯丙氨酸、酪氨酸、精氨酸)以及总氨基酸、必需氨基酸及非必需氨基酸的含量均显著高于全光谱光组、黄光组和红光组(P<0.05),而略高于蓝光组(P>0.05)。3)根据氨基酸评分(AAS)和化学评分(CS),欧洲舌齿鲈肌肉中含有丰富的赖氨酸,欧洲舌齿鲈必需氨基酸指数(EAAI)由高至低依次为绿光组、蓝光组、全光谱光组、黄光组、红光组。4) 5种光色环境下欧洲舌齿鲈肌肉脂肪酸组成类似,均检测出16种脂肪酸,其中绿光组欧洲舌齿鲈肌肉中饱和脂肪酸(SFA)、多不饱和脂肪酸(PUFA)的含量均显著高于黄光组和红光组(P<0.05),而单不饱和脂肪酸(MUFA)的含量在各组间均差异不显著(P> 0. 05);肌肉中C22∶6n-3(DHA)、C20∶5n-3(EPA)以及EPA+DHA含量均以绿光组最高,黄光组最低。由此可见,不同光色环境对欧洲舌齿鲈营养组成及比例产生了一定的影响,相对而言,绿光环境更适合欧洲舌齿鲈的养殖。     

高加索三叶草青贮饲料的制作及质量变化

将处于果后营养期的高加索三叶草Trifolium ambiguum分别做切短为2、5 cm长和未切短处理,同时进行添加和未添加微生物发酵剂对比试验,共设6个处理,每个处理3次重复。将青贮原料装袋,填满,压实,密封。贮藏45 d后,进行感官评定和营养成分测定。经感官评定,添加发酵剂且切短为2 cm处理效果最好,此时表现为醇香味浓,色黄绿,叶片结构完整良好,霉烂程度低。营养成分分析表明,添加发酵剂且切短为2 cm的粗蛋白(CP)含量达20.25%,中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量比未添加发酵剂且切短为2 cm青贮料中的低。总体来说,高加索三叶草单一高水分青贮效果良好,但添加微生物发酵剂后的品质优于未添加的处理。     

Possibility of amino acid nutrition in broiler

The consumption of poultry meats exceeds 50% of total meat consumption. With the outbreak of bovine spongiform encephalopathy and foot and mouth disease, the consumption of poultry meat is set to increase. The use of meat bone meal derived from cattle and pigs is prohibited. Therefore, plant protein has to be used more frequently and the importance of the study of amino acid nutrition is increasing. In order to improve dietary efficiency, it is necessary to elucidate the exact amino acid requirements of poultry. The amino acid requirements are not constant and are affected by various factors. By using the plasma amino acid concentration as a parameter, it is possible to predict the amino acid requirements within a short period using a small number of animals repeatedly. By satisfying the amino acid requirements through supplementing crystalline amino acids, it is possible to reduce dietary protein and excretory nitrogen simultaneously. However, when the dietary protein is reduced, the abdominal fat tends to increase. This is solved by deciding the optimum dietary protein level, but it is difficult to control the taste of poultry meat by dietary amino acids.     

木聚糖酶在肉仔鸡日粮中的应用

本文就木聚糖酶的来源、理化性质及其在肉仔鸡生产中的应用作一综述。     

饲用苎麻与稻草不同比例混合青贮品质及饲用价值评价

将鲜饲用苎麻与干稻草按质量比分别为90:10(R10)、80:20(R20)和60:40 (R40)贮存30、45 d和60 d后,进行感官评价、pH测定、营养成分分析以及饲用价值评价。结果表明:混合青贮产品感官评分较高,除R10组的30 d为2级尚好,其余各组均达到1级优等;处理对混合青贮pH无显著影响(P=0.462),对常规营养成分均有极显著的影响(P <0.01),处理与青贮时间对混合青贮的粗灰分有极显著的交互作用(P=0.0002);处理及青贮时间对混合青贮的相对饲用价值指数(RFV)均有极显著的影响(P <0.01),但未呈现出显著的交互作用(P> 0.05);R10组的RFV值较高,且不同青贮时间之间无显著差异(P> 0.05)。综合青贮品质及RFV,建议鲜饲用苎麻与干稻草混合青贮时适宜占比为80%～90%,青贮时间为45 d。