饲料级果胶酶对肉仔鸡生长性能的影响

试验研究日粮中添加饲料级果胶酶对肉仔鸡生长性能及经济效益的影响。选择体重、健康状况基本一致的AA肉仔鸡240羽,随机等分为试验组与对照组2个组,每组设3个重复,每重复40羽,分成2个处理组,试验组在基础日粮中添加0.01%含6 000u/g的饲料级果胶酶的日粮,对照组饲喂常规日粮,进行为期35d的试验。结果表明,与对照组相比,试验组日增重提高9.19%(P0.05);料重比降低7.06%(P0.05);死淘率降低33.73%(P0.01);羽均毛利润提高3.90元,提高幅度为14.18%。说明在日粮中添加饲料级果胶酶可显著提高肉仔鸡的生长性能,有效降低死淘率和提高肉鸡养殖效益。     

果胶酶对肉仔鸡生长性能及屠体性状的影响

试验选用 1日龄商品艾维茵肉仔鸡 4 32只。完全随机分为 2 4圈 ,每圈 18只 ,地面平养 5 4天。试验分为 4个处理 ,每个处理 6圈 ,分别饲喂 4种不同的日粮 ,即对照组 (基础日粮组 )、添加金霉素 5 0mg/kg日粮组、添加果胶酶 5 0 0mg/kg日粮组、添加果胶酶 10 0 0mg/kg日粮组。试验结果表明 ,果胶酶在肉仔鸡饲养前 2 1日龄的促生长效果显著 ,平均日增重 (ADG)和平均日采食量 (ADFI)均比对照组有显著增加 (P <0 .0 5 ) ,饲料转化率显著提高 (P <0 .0 5 ) ,与抗生素效果相当 ;2 1～ 4 2日龄时仅 5 0 0mg/kg果胶酶组出现ADFI比对照组显著增加 (P <0 .0 5 ) ,但饲料转化率较其它各组显著降低 (P <0 .0 5 )。 4 2～ 5 4日龄时 5 0 0mg/kg果胶酶组ADG显著高于抗生素组 (P <0 .0 5 ) ,饲料转化率显著提高 (P <0 .0 5 )。饲养全期 ,添加抗生素或果胶酶组ADG与对照组差异显著 (P <0 .0 5 ) ,ADFI仅5 0 0mg/kg果胶酶组与对照组有显著差异 (P <0 .0 5 )。     

饲料级β-甘露聚糖酶对肉仔鸡生长性能的影响

试验研究日粮中添加饲料级β-甘露聚糖酶对肉仔鸡生长与生产性能的影响。选择体重、健康状况基本一致的AA肉仔鸡360只，随机等分为试验组与对照组2个组，每组设3个重复，每重复60只，试验组饲喂在基础日粮中添加0.01％含50000 u/g的饲料级β-甘露聚糖酶的日粮，进行为期42 d的试验。结果表明，与对照组相比，试验组日增重提高10.40％（P〈0.05）；料重比降低7.14％（P〈0.05）；死淘率降低24.77％（P〈0.01），试验组毛利润高于对照组4.79元，提高幅度为17.95%。说明在日粮中添加饲料级β-甘露聚糖酶可显著提高肉仔鸡的生长性能，提高养殖经济效益。     

影响肉仔鸡生长性能的因素（下）

结果表明，采用高能量料，47日龄平均体重比饲喂低能量料重186g。饲料利用率高0.22，即如果肉鸡饲养到2.5kg上市，平均每只鸡用高能量料可节约饲料550g。当然，饲料中能量水平提高，必须导致饲料价格上涨。我们应当进一步试验，权衡两者的得失，采取正确的选择，使企业获得最大的效益。     

中草药饲料添加剂对肉仔鸡生长性能和免疫器官指数的影响

为了研究日粮中添加不同剂量的中草药饲料添加剂对肉仔鸡生长性能和免疫器官指数的影响,选取体重接近的健康1日龄AA肉仔鸡288只,按体重均匀分为4组,每组6个重复,每个重复12只鸡,即每组72只鸡。设对照组：日粮中不添加中草药饲料添加剂;试验Ⅰ组：日粮中添加0.5%中草药饲料添加剂;试验Ⅱ组：日粮中添加1%中草药饲料添加剂;试验Ⅲ组：日粮中添加2%中草药饲料添加剂。进行为期42d的饲养试验,测定各组的采食量、日增重、料重比以及脾脏指数和法氏囊指数。结果表明,肉仔鸡日粮中添加复方中草药制剂能够显著提高生长性能及免疫器官指数,日粮中添加1%复方中草药制剂效果最好。     

黄粉虫对肉仔鸡生长性能的影响

昆虫是地球上种类最多且生物量最大的生物,应该积极开发昆虫蛋白质资源。作为蛋白质饲料的昆虫种类有黄粉虫、白蚂蚁、蝇蛆粉等,但黄粉虫做为昆虫蛋白饲料在养殖业上的相关研究报道甚少,鉴于此,就黄粉虫对肉仔鸡生长性能的影响进行研究,为黄粉虫在新疆地区的蛋白饲料开发与推广     

影响肉仔鸡生和生长性能的因素

现代白羽肉鸡的主要特点是生长速度快，饲料消耗少，只有满足了肉仔鸡生长发育的各种需要，肉鸡遗传潜力才能得到充分发挥，并获得最佳的生产性能，本文剖析了影响肉仔鸡生产性能的一些主要因素。     

黄须菜对肉仔鸡生长性能的影响

本试验旨在评估黄须菜作饲料添加剂在生产中对肉仔鸡生长性能的影响。试验选择同一批次、21日龄、体重相近的AA肉食鸡2448只,随机分为A、B、C、D4组,每组设置6个重复,每个重复102只鸡。试验共进行21d。试验饲粮分别为:A组为对照组,只饲喂基础日粮;B组饲喂基础日粮+盐霉素(40～60mg/kg饲料);C组饲喂基础日粮+5%肉鸡复合预混料;D组饲喂基础日粮+5%黄须菜,以观察其对肉仔鸡日增重、饲料利用率、屠宰率和健康状况的影响。结果表明:与对照组比较,黄须菜能显著增加肉仔鸡的日增重和饲料利用率(P<0.05),而添加黄须菜组与添加预混料相比较差异不显著(P>0.05)。     

饲料品质对岭南黄肉仔鸡生长速度的影响

饲料品质对岭南黄肉仔鸡生长速度的影响陈庆旺（河南泌阳种鸡场）陈淑华（泌阳成人中专）邵亮（驻马店正大饲料有限公司）泌阳县种鸡场于１９９３年从广东省农科院畜牧研究所引进岭南黄肉鸡。该鸡种投放市场后以其肉质鲜美而深得广大消费者的欢迎。但由于饲养技术还存在某...     

Feed processing and structural components affect starch digestion dynamics in broiler chickens

1. A 2 × 2 factorial design was used to test the hypothesis that impaired intestinal starch digestibility is attributable to rapid passage of digesta from the gizzard to the intestine, and that, compared to steam pelleting, increasing the availability of starch through extrusion cooking may alleviate the potential negative effect of rapid digesta flow on starch utilisation.

2. Thus, 7-d-old-broiler chickens were distributed to 48 cages and given a wheat-based (WB) pelleted diet containing either coarse oat hulls (OH-Pel) or fine cellulose (Cel-Pel) until d 19 to stimulate divergent development of the gizzard. Thereafter, both groups were further subdivided and challenged with a WB diet containing cellulose in either pelleted (Cel-Pel) or extruded (Cel-Ext) form on d 20 and 22. Either excreta or intestinal contents were collected at time intervals after feeding and analysed for marker and starch.

3. OH-Pel increased gizzard size and holding capacity. No excessively high starch levels (maximum 25 g/kg) were detected in the excreta. However, 8 h feed-deprived birds given Cel-Pel and challenged with Cel-Pel exhibited higher starch excretion and showed large individual variation during the first 135 min of collection.

4. Contrary to the OH-Pel group, more digesta and starch passed to the jejunum at 1 and 2 h and ileum at 2 and 3 h after feeding for birds given Cel-Pel, resulting in lower jejunal and ileal starch digestibility.

5. Increased starch gelatinisation through extrusion processing significantly improved starch digestibility regardless of gizzard function. However, at 1, 2 and 3 h after feeding, more digesta was retained in the foregut of birds given Cel-Ext.

6. The current data showed that starch degradation rate is associated with the flow of digesta which is linked to gizzard development, and that enzymatic hydrolysis of intact starch granules may be limited with more rapid feed passage through the gut.     

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.     

早期限饲对肉仔鸡的影响

遗传育种选育和营养水平的改进,在使肉仔鸡生长速度不断提高的同时带来了一系列负面影响,如脂肪沉积、代谢性疾病、骨骼疾病、死亡率增加。早期限饲在改善这些问题上有一定的作用。本文综述了早期限饲对肉仔鸡的生产性能和健康状况等影响,并对早期限饲的进一步研究方向进行了展望。     

Effects of dietary fiber and threonine on performance,intestinal morphology and immune responses in broiler chickens

The present experiment was conducted to investigate the effects of fiber and threonine (Thr) on growth performance, intestinal morphology and immune responses of broiler chickens. A total of 420 one-day-old mixed sex broiler chicks (Ross 308) were randomly divided into 6 experimental diets and 5 replicates of 14 chicks based on a factorial arrangement (2 × 3) from 1 to 42 d of age. Experimental factors included dietary supplemental fiber type (no supplemental fiber [NSF], 30 g/kg sugar beet pulp [SBP] or 30 g/kg rice hull [RH]) and Thr inclusion level (100% or 110% of Thr requirement recommended by breeder company [Ross 308]). Growth performance of broilers was assayed at different periods of the experiment. Intestinal morphometric features were measured at 21 d of age. Antibody titer against sheep red blood cells (SRBC), Newcastle and influenza disease viruses were measured on d 30 of trial. Dietary inclusion of SBP and RH significantly decreased feed intake and weight gain during the entire rearing period (P < 0.05). Interaction of fiber and Thr had no beneficial effects on the performance of chickens across the entire rearing phase. Dietary supplementation of 110% Thr required level improved jejunal morphometric features (P < 0.05), whereas its inclusion with fibrous materials failed to show the same effects. Dietary supplemental Thr together with SBP significantly increased antibody production against SRBC (P < 0.05). In conclusion, although supplemental 30 g/kg fibrous materials impaired growth performance, inclusion of SBP along with 110% Thr level improved the humoral immunity in broiler chickens.     

Effects of salinomycin and Bacillus subtilis on growth performance and immune responses in broiler chickens

The present study was undertaken to compare the effect of salinomycin and Bacillus subtilis on growth performance, serum antibody levels against Clostridium spp. and Eimeria spp., and cytokine mRNA expression levels in broiler chickens raised in the used litter. Broiler chickens fed a diet containing salinomycin showed lower (P < 0.05) body weights compared with the control diet-fed counterparts. Serum nitric oxide levels were significantly (P < 0.05) elevated in chickens fed the B. subtilis-enriched diet compared with those on either the salinomycin-fed or control diet-fed chickens. None of the dietary treatments affected (P > 0.05) serum antibody levels against Clostridium perfringens toxins. Both salinomycin and B. subtilis significantly lowered (P < 0.05) the serum levels of Eimeria-specific antibodies compared with the control group. Salinomycin, but not B. subtilis, significantly modulated (P < 0.05) the expression of cytokines encoding interferon-γ (IFN-γ), interleukin10 (IL-10) and tumor necrosis factor superfamily 15 (TNFSF15) compared with the control group. In conclusion, dietary salinomycin and B. subtilis affected serum anticoccidial antibody and intestinal cytokine expression, but failed to improve growth performance in broiler chickens. Further study is warranted to investigate the mode of action of salinomycin on host immune response and growth performance in broiler chickens.     

Thermostable xylanase derived from Trichoderma citrinoviride increases growth performance and non-starch polysaccharide degradation in broiler chickens

ABSTRACT

1. The aim of this trial was to determine the optimal supplementation level of a xylanase enzyme from Trichoderma citrinoviride on growth performance, apparent ileal and total tract nutrient retention, intestinal morphology, and intestinal concentration of volatile fatty acids in broiler chickens.

2. A total of 600 broiler chickens (Ross 308) of mixed sex were randomly allotted to four treatments, on the basis of similar body weight. The dietary treatments were made from a corn-wheat-soy based diet supplemented with either 0, 3750, 7500, or 11 250 XU/kg xylanase and were fed to 32 d of age.

3. A linear response to increasing dietary xylanase was demonstrated for overall weight gain (P < 0.05) and feed conversion ratio (P < 0.05). The apparent total tract digestibility of dry matter and gross energy, and the coefficient of apparent ileal digestibility (CIAD) of N and soluble non-starch polysaccharides were linearly improved when xylanase was added to the diet (P < 0.05). Moreover, a linear increase (P < 0.05) was observed in the CIAD of Arg, Lys, and Try with increasing dietary levels of xylanase.

4. The viscosity of digesta in ileum was linearly decreased when dietary xylanase level increased (P < 0.05).

5. An increase in villus height of the duodenum and jejunum were observed with increasing dietary levels of xylanase (linear, P < 0.05).

6. Overall, the results showed that the effects of dietary xylanase supplementation on broiler performance was determined through effects on nutrient availability and intestinal morphology.     

The effect of dietary lysozyme with EDTA on growth performance and intestinal microbiota of broiler chickens in each period of the growth cycle

Lysozyme is a potential replacement for antibiotics in the poultry industry. Two trials were conducted using new or used litter to determine the effect of 100 ppm lysozyme in feed on growth performance and intestinal microbiota of broiler chickens in each period of the growth cycle. The new litter trial and used litter trial were each analyzed as a one-way analysis of variance with length of time in which 100 ppm lysozyme was fed to the birds as the main factor (no lysozyme d zero to 35; positive lysozyme d zero to 4; positive lysozyme d 5 to 14; positive lysozyme d 15 to 24; positive lysozyme d 25 to 35; positive lysozyme d zero to 35; positive virginiamycin d zero to 35). Effects of lysozyme were not detected under clean conditions (P > 0.05). When used litter was provided, growth performance was not improved by lysozyme (P > 0.05). However, feeding lysozyme to birds from d 5 to 14 and throughout the trial reduced the number of E. coli in the ileum compared with feeding virginiamycin (positive lysozyme d 5 to 14 and zero to 35, and virginiamycin d zero to 35: 1.7 × 10⁴ cfu g⁻¹, 1.9 × 10⁴ cfu g⁻¹ and 9.3 × 10⁴ cfu g⁻¹, respectively) to birds (P < 0.05). Dietary lysozyme at 100 ppm can change intestinal microbiota of broiler chickens.     

Molecular study and genotyping of Cryptosporidium baileyi and Cryptosporidium parvum from free-range and commercial broiler chickens in Guilan province,Iran

Cryptosporidiosis acutely impacts the digestive and/or respiratory tract of the birds in many species of various orders. More importantly, it is also well known as a significant zoonotic disease, which can lead to diarrhea in humans and livestock. Regarding increasing demand for free-range products and increasing the number of free-range poultry farms, the present paper evaluated histopathological and molecular detection of Cryptosporidium baileyi and Cryptosporidium parvum in free-range and commercial broiler chickens in the north part of Iran. For this purpose, 100 fecal and tissue samples of the chickens in Guilan province were collected. After microscopic examination using Ziehl-Neelsen staining, molecular analyses of the fecal samples were processed by Nested-PCR targeting the 18S rRNA gene followed by sequencing of the amplicons and phylogenetic analyses. Eventually, the tissue samples were studied for histological lesions. Findings demonstrated the presence of Cryptosporidium baileyi and Cryptosporidium parvum in 6 % and 2 % of fecal samples, respectively. This is the first identification of C.parvum in avian hosts in Iran, and for the first time, C.baileyi and C.parvum are shown in native free-range chickens in Iran. All of the PCR positive birds with clinical symptoms showed gross lesions of respiratory infections. There was no significant difference between infection rate in free-range and commercial broiler chickens; however, the infection rate was significantly higher in chickens <25 days old. To conclude, we present here a notable Cryptosporidium infection rate in the free-range chicks in Iran, which notify the role of this host as a reservoir and should be more noted due to the economic and zoonotic importance.     

Intestinal function and gut microflora of broiler chickens as influenced by cereal grains and microbial enzyme supplementation

A study was conducted to investigate the effect of the key cereal grains and a microbial enzyme supplement on broiler chicken performance, gut microflora and intestinal function. Ingestion of the barley-based diet was associated with low 28-day body weight, decreased feed intake and high FCR. The supplemental enzyme increased feed intake and weight gain of the chickens on a wheat-based diet. The pH of the gizzard and caecal contents varied with the grain type. Enzyme supplementation reduced ileal viscosity, particularly in birds that received the diet based on wheat. The birds on the barley-based diet had lower ileal digestibility of dry matter, protein and energy than those given maize and sorghum-based diets. The ileal digestibility of starch was increased by enzyme supplementation. Enzyme supplementation increased the number of total anaerobic bacteria in the gizzard of birds fed on sorghum and increased lactobacilli in the gizzard of those fed both sorghum and wheat. The birds fed the sorghum-based diet had the lowest counts of caecal total anaerobic bacteria and lactobacilli. Jejunal villus height and villus:crypt ratio of birds fed the barley-based diet were the lowest when compared with those fed the other diets. Enzyme application induced an increase in villus height and villus:crypt ratio of birds on wheat, crypt depth on barley and a reduction in crypt depth of chickens on the sorghum-based diets. The highest activity of maltase and the lowest activity of sucrase were observed in tissue from birds fed on maize and sorghum-based diets respectively. The differences in the performance of broilers on cereal grains could be explained by changes in intestinal morphology, enzyme activities and gut microflora as well as nutrient digestibility. The improved performance by supplemental enzyme in wheat-fed chickens was associated with beneficial changes in intestinal morphology and digesta viscosity.     

早期数量限饲对肉用仔鸡生产性能、胴体品质的影响

试验研究了早期数量限饲对肉用仔鸡生产性能、胴体品质的影响。以320只1日龄AA+肉用仔鸡为试验动物。设4个处理组,每个处理组4个重复,每个重复20只肉仔鸡。对照组根据AA+商品代肉鸡营养标准配制。各处理肉用仔鸡1～7日龄均为自由采食,8～14日龄对照组、限饲90%组、限饲80%组和限饲70%组分别饲喂自由采食量的100%、90%、80%和70%,15日龄恢复自由采食,以后按常规饲养管理。每周末,以重复为单位全部称重。分别于42、49日龄,每个重复随机抽取4只肉用仔鸡禁食12h、称重、屠宰、测定屠体品质。试验结果表明:在第2周,限饲各组肉仔鸡的体重和日增重分别显著低于对照组(P0.05);在第3周,限饲90%组完成补偿生长,体重与对照组差异不显著(P0.05);在第4周,限饲80%和70%组完成补偿生长,体重与对照组差异不显著(P0.05);5、6、7周及2～6、2～7周各组在体重、日增重、日采食量和饲料转化率等都无显著差异(P0.05)。早期数量限饲对肉仔鸡胴体特性没有显著影响(P0.05),限饲70%～80%,具有改善饲料转化效率、胸肌率、腹脂率的作用。