Effect of range enrichment on performance,behavior, and forage intake of free-range chickens

The aim of the present study was to analyze the effect of range enrichment (trees or tall grass stand) on the performance and herbage intake of free-range chicken. This trial was conducted in 2 different seasons (winter and summer) comparing a standard free-range system with 2 kinds of range enrichment: a stand of sorghum (a tall grass) and olive trees. Two hundred fifty male naked neck chickens were used in each season and system; performance, behavior, forage intake, and body lesions were recorded. Productive performance was not affected by range enrichment. However, in the presence of trees or tall grass stand, no predation losses were experienced; whereas, in the standard paddock, cases of predation by raptors or crows were registered, mainly during the first period of rearing. Consequently, mortality rate was significantly lower in the enriched environment. Control chickens stayed indoors more rather than forage in the pasture, whereas, in enriched environments, birds spent more time outdoors and widely exploited the available pasture. Forage intake was significantly influenced by rearing system and season; chickens reared under olive trees had higher herbage ingestion, exploring the available area up to almost 50 m from the hut. With the olive trees, chickens also showed the lowest frequency of foot and breast damage.     

Seroconversion to avian influenza virus in free-range chickens in the Riverland region of Victoria

Background Since 2005, H5N1 avian influenza (AI) has spread from South-East Asia to over 60 different countries, resulting in the direct death or slaughter of over 250,000,000 poultry. Migratory waterfowl have been implicated in this spread and in Australia there have been numerous isolations of low-pathogenicity AI virus from wild waterfowl and shorebirds. The Department of Human Services, Victoria maintains 10 sentinel free-range chicken flocks in the Riverland at locations that are populated by large numbers of waterfowl known to carry a range of strains of AI. Objective This study analysed historical samples collected in 1991–94 and 2003–06 from the library of serum samples for antibodies against AI to assess the potential for transfer of AI virus from wild waterfowl to free-range poultry. Results Of the 2000 serum samples analysed, 17 were positive for antibodies against AI and 87 were suspect, with a clustering of positive and suspect results in the years 1994, 2003 and 2004. There was also a clustering of positive samples at the site of the Barmah flock. Nine sequential sets of sera from individual chickens with at least one positive result were identified. Analysis of these sequential sets showed that infection was acquired on site but that the antibody response to AI infection was short-lived and was no longer detectable at 8 weeks after the positive finding. Conclusion The surveillance of sentinel chickens is a potential avenue for monitoring the circulation of AI viruses and could provide an early warning system for the commercial poultry industries.     

A study on feeding hazelnut kernel oil meal as a protein source for broiler chickens

An experiment was conducted to evaluate the effect of substituting different levels of hazelnut kernel oil meal (HKM) for soybean meal (SBM) in diets for broiler. A total of 450 one-day-old female Ross 308 broiler chicks were allocated randomly to three treatment groups of 150 birds each in a randomized design. Each treatment group consisted of five replicates each of 30 chicks. All diets (in mash form) were formulated to meet nutrient concentrations recommended for broilers. The experiment lasted for six weeks. In the experiment, an SBM control (SBM) diet was compared to two HKM diets, replacing 50 (50HKM) and 100% (HKM) of SBM protein, respectively. Body weight gain, feed intake and feed conversion ratio of broilers were adversely affected ( P  < 0.05) by the HKM diets at 42 days of age. Broilers fed 50HKM and HKM had growth performances similar ( P  > 0.05). The carcass yield and abdominal fat pads of birds fed diets with SBM were higher ( P  < 0.05) than those of chicks fed the 50HKM and HKM diets. The edible inner organ weight of chicks fed diets with HKM was the heaviest ( P  < 0.05). It is concluded that SBM cannot be replaced even up to 50% with HKM in commercial broiler diet.     

Free-range and organic farming: Eggshell contamination by mesophilic bacteria and unusual pathogens

The high incidence of foodborne illnesses caused by the consumption of eggs in industrialized countries is the main reason we decided to determine the microbial load on the surface of eggshells from free-range and organic farming. The objective was to compare which was better for ensuring the least possible health risk to the consumers, focusing on consumption of raw eggs by immune-compromised people. Bacteria come from the intestine of the animal or subsequent contamination. When eggs are cracked, bacteria from the shell reach the yolk and the albumen, and grow during manipulation and preservation, causing foodborne diseases in consumers. Microorganisms such as Salmonella, Listeria monocytogenes, Campylobacter, Enterobacteriaceae (including E. coli serotype O157: H7), Staphylococcus, Enterococcus, and mesophilic aerobic bacteria, were examined. The presence of bacteria on eggshells depends on hygienic conditions of the farming and packaging industries. Hygienic measures, such as strict cleaning and disinfection of surfaces in contact with eggs in packaging industries, would be a protective factor to minimize the contamination of eggshells. The total absence of pathogens demonstrates the relevance for human consumption of eggs coming from both free-range and organic farms, though YOPI (young, old, pregnant, or immune-compromised) people preferably should cook eggs in which bacteria contaminating the outer surface are killed.     

生物有机肥对墨西哥玉米饲用价值的影响

研究了4个浓度的生物有机肥（0、50、60和70 kg·667m-2）对墨西哥玉米（Zea mexicana）生长特性与牧草养分和饲用价值的影响。结果表明,随施肥浓度的增加,墨西哥玉米的叶长、株高、鲜干草产量、粗蛋白（CP）、粗脂肪（EE）、干物质消化率（DDM）、随意采食量（DMI）和相对饲用价值（RFV）均呈增加趋势,而其粗灰分（CA）、酸性洗涤纤维（ADF）和中性洗涤纤维（NDF）均呈降低趋势。     

Evaluation of ground grain versus pre- and post-pellet whole grain additions to poultry diets via a response surface design

1. The objective of this study was to compare the effects of pre- and post-pellet whole grain wheat additions to diets on growth performance, gizzard and pancreas development, nutrient utilisation and starch and protein (N) digestibility coefficients in broiler chickens via an equilateral triangle response surface design.

2. The three apical treatments of the equilateral triangle comprised (1A) a standard diet containing 600 g/kg ground wheat, (2B) the same diet containing 600 g/kg pre-pellet whole wheat and (3C) the same diet containing 300 g/kg ground wheat and 300 g/kg post-pellet whole wheat. Seven blends of the three apical diets were located within the triangle to complete the design and a total of 360 male Ross 308 chicks were offered the ten experimental diets from 7 to 28 d post-hatch. Model prediction and response surface plots were generated with R 3.0.3 software.

3. The most efficient FCR of 1.466 was observed in birds offered an almost equal mixture of the pre- and post-pellet whole grain apical dietary treatments, which corresponded to 172 g/kg ground grain, 256 g/kg pre-pellet whole grain, 172 g/kg post-pellet whole grain in a diet containing 600 g/kg wheat.

4. The most efficient energy utilisation (ME:GE ratio of 0.766) was observed in birds offered a blend of the ground grain and pre-pellet whole grain apical dietary treatments which corresponded to a mixture of 384 g/kg pre-pellet whole grain and 216 g/kg ground grain.

5. Pre-pellet whole grain feeding generated the most pronounced responses in increased relative gizzard contents, reduced gizzard pH and increased relative pancreas weights. Consideration is given to the likely differences between pre- and post-pellet whole grain feeding.     

昆虫蛋白粉作为蛋白原料对肉兔生长性能、养分消化及饲养成本的影响

本研究评估了日粮添加昆虫蛋白粉(黄粉虫)替代豆粕对肉兔生长性能、养分消化及饲养成本的影响.试验选择平均体重为(712.16±0.37)g的60只肉兔,随机分为2组,每组5个重复,每个重复6只.对照组和处理组肉兔在整个为期8周的饲养试验中分别饲喂8％豆粕型和8％黄粉虫型基础日粮.结果:处理组肉兔12?w体重较对照组显著提...     

Effects of a meal feeding regimen and the availability of fresh alfalfa on growth performance and meat and bone quality of broiler genotypes

1. The aim of this study was to identify a feeding regimen that encourages good pasture use in slow (SG) and fast (FG) growing broiler genotypes under free-range management.

2. SG and FG birds fed on either an ad libitum (ADB) or a meal feeding (MEF) programme were given free outdoor access with or without fresh alfalfa from day 22 to 72 and from day 22 to 45, respectively. In two consecutive trials, 800 birds of each genotype were included in a factorial design using groups of 40 birds replicated 5 times.

3. Fresh alfalfa consumption did not improve growth performance and meat quality attributes, whereas the feeding regimen had significant implications. When compared with their ad libitum-fed counterparts, meal-fed birds showed a significantly lower body weight at a considerably lower feed consumption rate, leading to a more favourable feed conversion ratio (FCR) during the course of the experiment.

4. The MEF regimen with a strong feed limitation significantly increased crop and gizzard weight in both genotypes. In FG birds, water holding capacity, drip loss, cooking loss and pH 45 in the breast and thigh meat were adversely affected by MEF; however, feed restriction demonstrated benefits with significant decreases in muscle fat accumulation. In SG birds, decreases in protein and dry matter content of the breast and thigh muscle with meal feeding were conclusive.

5. In both genotypes, there was no treatment-related effect on meat yield, mineral composition of the meat or bone mechanical properties.

6. In conclusion, MEF, irrespective of alfalfa intake, may provide a viable method to decrease FCR; it may be able to contribute to the production of chickens with lean carcasses but it was not capable of improving overall meat quality.     

家禽有机硒营养研究进展

硒是动物所必需的微量元素之一,为谷胱甘肽过氧化物酶的重要成分,能消除体内有害自由基。有机硒相对于无机硒毒性小,生物利用率高,生物活性强。本文就目前国内外对有机硒在家禽营养中的研究进展及应用现状进行综述。     

Formulation challenges of organic poultry diets with readily available ingredients and limited synthetic methionine

Organic agriculture has increased greatly over the past several years as consumer demand for these products has risen. Organic meat production, including poultry, has grown especially quickly, resulting in increasingly stringent guidelines being put in place to ensure safe, uniform, and ideal products for these consumers. Feed formulation and manufacturing for organic poultry in the United States are strictly regulated by the United States Department of Agriculture National Organic Program. Currently, no synthetic amino acids are allowed to be used in organic poultry diets in the United States except for limited quantities of synthetic methionine since it is typically considered the first or second limiting amino acid in corn and soybean meal based poultry diets and it is a critical nutrient for maintaining bird growth and productive performance, especially regarding egg size in laying hens. The aim of the review herein is to discuss the impacts that current organic regulations on synthetic methionine have on diet formulation when using readily available ingredients. High levels of crude protein must be used to meet bird methionine requirements with this restriction in place, which both increases feed costs and can have negative impacts on bird health and on air quality and the surrounding environment due to increased ammonia emissions. Atypical feed formulation strategies have been explored to address this issue, including such methods as feeding alternative ingredients and providing forage materials. Another possibility would be to use an average lifetime maximum inclusion rate for synthetic methionine, which may allow for better flexibility to provide sufficient methionine throughout various phases of growth and production since the requirements of the bird change with age.     

Inclusion levels and modes of whole grain incorporation into wheat-based rations differentially influence the performance of broiler chickens

1. The objective was to compare three whole grain (WG) inclusion levels (7.5, 15 and 30%) offered to broiler chickens by three modes of WG incorporation: (i) pre-pellet WG inclusion, (ii) post-pellet WG inclusion as a blend of WG and pelleted concentrate and (iii) post-pellet WG inclusion where WG and pelleted concentrate were provided in separate feed trays against a ground-grain, wheat-based control diet.

2. Ten dietary treatments were offered to 6 replicate cages (6 birds per cage) of male Ross 308 chickens from 7 to 28 d post-hatch. The effects of treatment on relative gizzard weights, gizzard contents, pancreatic weights and pH of gizzard digesta were monitored. Parameters of growth performance, nutrient utilisation (apparent metabolisable energy [AME], metabolisable to gross energy [ME:GE] ratios, nitrogen [N] retention and N-corrected AME [AMEn]), apparent starch and protein (N) digestibility coefficients and disappearance rates in for small intestinal segments and concentrations of free amino acids in plasma taken from the anterior mesenteric vein were determined.

3. Whole grain feeding (WGF) did not influence weight gain, but 30% post-pellet blended and 15 and 30% post-pellet separated treatments significantly depressed (P < 0.05) feed intakes while the 30% post-pellet separated treatment improved (P < 0.01) feed conversion ratios (FCR). WGF regimes significantly increased relative gizzard weights.

4. Overall, WGF generated profound responses in AME, ME:GE ratios, N retention and AMEn that were highly correlated with relative gizzard weights. In general, WGF improved starch and protein (N) digestibilities and again there were some correlations with these outcomes and relative gizzard weights.

5. Post-pellet WG inclusions where WG and pelleted concentrate were offered separately provided chickens with the opportunity to choice feed. Birds showed a preference for the relatively high-protein pelleted concentrate and at 30% WG, this resulted in an improvement in FCR of 7.69% (1.260 versus 1.365; P < 0.001) relative to the ground-grain control diet.     

有机锰在畜禽生产中的应用

锰是动物机体的必需微量元素之一,具有促进动物生长、增强繁殖功能、维持骨骼形成和改善胴体品质等营养生理作用。本文主要介绍有机锰在畜禽生产中的营养功能。     

择食饲喂对肉鸡生产性能和养分代谢的影响

试验研究择食饲喂对肉鸡生产性能、饲料养分利用率和肉鸡整体CP、能量转化率的影响。将144只22日龄艾维茵肉鸡随机分成3组,每组4个重复,每重复12只,分别饲喂粉碎玉米 浓缩料、豆粕 平衡料的试验日粮和基础全价对照日粮,每处理均设两个食槽。结果表明:(1)择食饲喂比饲喂全价混合日粮时生产性能略有下降;(2)择食饲喂对日粮干物质、粗蛋白和能量的表观代谢率无显著影响(P>0.05);(3)择食饲喂对肉鸡整体CP、能量沉积率无显著影响(P>0.05);(4)择食饲喂玉米组,日粮CP以及赖氨酸转化为体增重的效率显著高于另两组(P<0.05)。     

生态放养鸡饲养管理技术

我国农业经济快速发展,养殖工作的重要性变得更为突出,其中以生态放养鸡的饲养管理工作最为重要。但是在生态放养鸡的饲养管理工作开展过程中,却发现存在一定的问题,这些问题来自于人为及自然等2个方面,导致生态放养鸡的饲养管理技术没有从根本上得到最大程度的提升。养殖者应对生态放养鸡饲养管理工作的开展予以全面化重视,只有确保相关的技术要点得到实现,才能提升生态鸡的养殖水平。     

不同饲喂方式对育肥水牛胴体特征和肉品质的影响

文章旨在研究不同饲喂方式对育肥水牛生长性能、胴体特征、肉品质及抗氧化的影响.试验将36头平均初始体重为(207.67±12.81)kg的水牛随机分为4组,每组3个重复,每个重复3头.处理1组和处理2组水牛采用放牧的形式,即分别在象草及象草与柱花草间作的牧场放牧,处理3组和处理4组饲喂浓缩饲料的同时补充2％和4％的象草,...