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.     

Chitosan and its oligosaccharide derivatives (chito‐oligosaccharides) as feed supplements in poultry and swine nutrition

Chitosan is a non‐toxic polyglucosamine, widespread in nature, which is deacetylated to varying degrees form of chitin, a component of exoskeleton of shrimps, crabs and insects. Because chitosan contains reactive functional groups, that is, amino acids and hydroxyl groups, it is characterised by antimicrobial, anti‐inflammatory, anti‐oxidative, antitumor, immunostimulatory and hypocholesterolemic properties when fed as dietary additive for farm animals. This article reviews and discusses the results of studies on the effects of dietary chitosan and its oligosaccharide derivatives on performance and metabolic response in poultry and pigs, that is, haematological, biochemical and immunological blood characteristics, microbiological profile of intestines, intestinal morphology and digestibility of nutrients, as well as on the quality of meat and eggs. The results of most of the experiments presented in this review indicate that chitosan used as a feed additive for poultry and pigs has some beneficial, biological effects, including immunomodulatory, anti‐oxidative, antimicrobial and hypocholesterolemic properties. These properties of chitosan, unlike many other kinds of feed additives, were often reflected in improved growth performance (body weight gain and/or feed conversion ratio) of young animals, that is, broiler chickens and weaned pigs.     

蛋鸡产蛋期蛋白质需要量的研究及数学模型的应用

针对产蛋鸡蛋白质和氨基酸需要量的研究现状及相关数学模型的应用作一综述。     

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.     

复合氨基酸对蛋鸡不同产蛋期生产性能的影响

选择145-180日龄和202-237日龄的蛋鸡,用复合氨基酸添加剂进行饲喂试验,按每羽产蛋鸡5 mL剂量拌入1 d饲料中分4次饲喂,隔日1次。结果表明,实验组比对照组产蛋率分别提高1.77%、1.86%（P〉0.05）;145-180日龄蛋鸡的平均蛋重提高1.89 g（P〈0.05）,202-237日龄蛋鸡平均蛋重提高2.57 g（P〈0.01）;投入产出比分别为1∶1.03和1∶1.62。     

A qualitative risk assessment of cleansing and disinfection requirements after an avian influenza outbreak in commercial poultry

ABSTRACT

1. During an avian influenza (AI) outbreak in the United Kingdom, the joint aim of the poultry industry and the Government is to eliminate and prevent the spread of infection, through control measures based on the current European Union (EU) Council Directive (2005/94/EC). An essential part of these measures is the cleansing and disinfection (C&D) of infected premises.

2. This risk assessment assessed the differences in re-infection in a repopulated flock if the EU Directive is interpreted to permit secondary C&D to be undertaken either with or without dismantling complex equipment. The assessment estimated the probability of virus survival on different types of equipment in a depopulated contaminated poultry house before and after preliminary and secondary C&D procedures. A risk matrix spreadsheet tool was used to carry out the assessment and concluded that, provided secondary C&D is carried out with due diligence (i.e. carried out to a defined code of practice as agreed by both industry and policymakers), the risk of re-infection from equipment is negligible, both with and without dismantling complex equipment in all farm types considered.

3. By considering the equipment types individually, the assessment identified those areas of the house which may still contain viable virus post-preliminary C&D and on which attention should be focussed during secondary C&D. The generic risk pathway and matrix spreadsheet tool have the potential to be used for other pathogens and species, given appropriate data.     

去盲肠法测定家禽氨基酸消化率研究进展

本文就采用去盲肠法测定家禽饲料中可消化氨基酸研究进展作一综述。     

Efficacy of feed enzymes in pig and poultry diets containing distillers dried grains with solubles: a review

Distiller's dried grains with solubles (DDGS), a coproduct of the ethanol industry, are often used as feed material in livestock and poultry nutrition. Results of many experiments have indicated, however, that a high dietary level of DDGS can negatively affect the digestibility of nutrients and the performance of monogastric animals due to their high content of non‐starch polysaccharides (NSP). Nevertheless, using high levels of DDGS as a protein source in livestock diets can be still economically justifiable in view of the rising prices of soya bean meal and other protein sources. The aim of some recent experiments with poultry and pigs was to improve the nutritional efficacy of high‐NSP diets through the addition of feed enzymes. As presented and discussed in this review article, the efficacy of feed enzymes added to poultry and pig diets containing DDGS is not consistent and depends on many factors. However, NSP‐hydrolysing enzymes generally seemed to be more efficient than phytases in terms of the digestibility of nutrients and the growth performance of poultry and pigs fed high‐DDGS diets. For this reason, supplementation with NSP‐hydrolysing enzymes could be an efficient way to enable the use of increased levels of DDGS in poultry and pig diets.     

家禽氨基酸需要量的研究进展

氨基酸是构成蛋白质的基本单位，家禽对蛋白质的需要实际上是对构成蛋白质的多种氨基酸的数量及相互比例的需要。该文着重综述了家禽氨基酸需要量的评定方法；影响家禽氨基酸需要量的因素；家禽氨基酸需要量的表示方法及家禽理想氨基酸模式。     

蛋鸡氨基酸营养的研究进展

近年来,随着畜牧业的发展,饲料原料匮乏以及环境污染问题日趋严重,作为蛋鸡营养中的重要内容,氨基酸的营养研究重点也在随之发生转变.以理想氨基酸模式及相应的分析研究方法为核心,在蛋鸡氨基酸需要量和氨基酸营养调控领域出现了大量新的研究成果与最新发现,从可持续发展、生态环保、动物福利等宏观方面到氨基酸的营养作用原理等机制研究上均有明显进展,研究不断深入.本文综述了近几年来产蛋鸡理想蛋白质模式、产蛋鸡和蛋雏鸡氨基酸需要量以及氨基酸营养调控方面的最新研究进展,并探讨了蛋鸡氨基酸营养在未来发展的可能趋势.     

评定蛋鸡豆粕代谢能和氨基酸可利用率的研究

本试验旨在评定罗曼蛋鸡对不同来源豆粕表观代谢能(AME)和氨基酸可利用率(AAA),并用傅里叶近红外光谱(NIRS)分析技术建立其预测模型。选择248只体重(1.60±0.10)kg、产蛋率85%的36周龄罗曼蛋鸡,按单因素完全随机设计,分为31组,每组8个重复,每个重复1只鸡。在训饲的基础上,采用全收粪法评定30种不同来源豆粕和1种基础饲粮的AME和AAA,然后用NIRS技术建立其生物效价的预测模型。结果如下:1)不同来源的30种豆粕AME在11.95~14.87 MJ/kg之间,平均值为(13.24±0.67)MJ/kg;总氨基酸可利用率(TAAA)在89.99%~94.96%之间,平均值为(93.73±1.23)%。2)豆粕AME的NIRS预测模型的校正决定系数(Rcal2)、交叉验证系数(Rcv2)、外部验证系数(Rval2)分别为99.24%、83.79%、80.73%,外部验证标准差(RMSEP)为0.22 MJ/kg;TAAA的NIRS预测模型的Rcal2、Rcv2、Rval2范围分别为94.20%~99.97%、76.38%~97.32%、61.80%~99.42%,RMSEP范围为0.06%~1.00%。结果表明:1)不同来源豆粕的AME、AAA在罗曼蛋鸡上有较大差异;2)利用NIRS分析技术可建立罗曼蛋鸡豆粕的AME、AAA预测模型,模型的Rcal2及预测的RMSEP较好。     

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.