蛋氨酸羟基类似物及甜菜碱对肉鸡血清生化指标的影响

试验选用AA肉仔鸡72只,采用3×2二因素随机分组试验设计,共计6个处理组,每处理4个重复,每重复3只鸡。在笼养条件下,对试鸡进行急性热应激试验,试验共进行1周,测定和评价甜菜碱、DL-蛋氨酸和液态蛋氨酸羟基类似物在急性热应激下对肉鸡血清生化指标的影响。结果表明,在急性热应激下,添加甜菜碱可不同程度地降低血糖、甘油三酯、尿酸和尿氮的水平。蛋氨酸羟基类似物(MHA)有利于防止热应激下血糖的升高,降低血清甘油三酯的含量,MHA比蛋氨酸更利于降低血清甘油三酯的含量;与蛋氨酸相比,添加MHA可降低血清甘油三酯、尿酸和尿氮的水平。甜菜碱可降低血中二氧化碳(CO2)的排出。     

叶酸对肉仔鸡营养物质利用的影响

选用艾维茵商品代白羽肉鸡120只,随机分成4组,按叶酸添加水平不同分为4个不同处理组,分别为0、0.75、1.5、3.0mg/kg,于35～42日龄用全收粪法进行消化代谢试验,研究叶酸对肉仔鸡营养物质利用率的影响。研究结果表明,添加叶酸可以不同程度地提高饲料养分表观利用率,1.5mg/kg组的干物质、粗蛋白、粗脂肪、粗纤维、有机物和无氮浸出物的表观代谢率最高,分别比对照组提高10.33%、19.83%、14.32%、13.89%、6.07%和16.09%,差异显著,而其余各养分的代谢率各组间均差异不显著。     

Effect of stocking density on performance of broiler chicks

In two experiments space allowances of 0.143, 0.122, 0.105 and 0.093 m²/bird and 0.093, 0.078, 0.064 and 0.047 m²/bird were used and their effects on live‐weight, food consumption and food conversion of Cobb broilers up to 10 weeks old were measured.

When the space allowance was greater than 0.093 m²/bird there was no effect on any of the characters studied.

At 10 weeks old a decrease in space allowance from 0.093 to 0.047 m²/bird was accompanied by reduced final live‐weight and food consumption and increased efficiency of food conversion; the effect on live‐weight was smaller at 9 weeks and was not significant at 8 or 7 weeks.

It was concluded that in broiler experiments ending at 8 weeks a space allowance of 0.078 m²/bird (0.8 ft²/bird) is more than adequate.     

Effect of ochratoxin A on Escherichia coli-challenged broiler chicks

A study was conducted to evaluate the effects of ochratoxin A (OA) on Escherichia coli-challenged broiler chickens. Day-old broiler chicks were separated into two groups of 92 chicks each, with one group fed a control mash diet, and the other fed a mash diet containing 2 ppm OA. On day 14, each group was further separated into two groups, with one group inoculated with E. coli O78 (1 x 10(7) colony-forming units/0.5 ml), whereas the other group was not inoculated with E. coli. After E. coli inoculation on day 14, four birds from each group were euthanatized at 1, 2, 3, 5, 7, 10, 14, and 21 days postinoculation. Escherichia coli infection caused dullness, depression, huddling, and diarrhea. Mortality was 14.3% in chicks infected with E. coli but fed no OA. Mortality increased to 35.7% in chicks fed OA and infected with E. coli. Decreased body weight and reduced feed intake were observed in chicks fed OA, and the effects were more pronounced in chicks fed OA and infected with E. coli. Increased serum levels of aspartate aminotransferase, alanine aminotransferase, uric acid, and creatinine and decreased levels of total proteins, albumin, globulins, calcium, and phosphorus were observed in OA-fed birds. Escherichia coli infection did not cause significant alteration in any of the serum biochemical parameters. The presence of OA in poultry rations increased mortality and the severity of an E. coli infection.     

Effect of different levels of rice bran processed by various techniques on performance of broiler chicks

1. Rice bran processed by extrusion cooking, roasting or pelleting and treated with antioxidant was used in broiler starter and finisher diets at various concentrations up to 500 g/kg. 2. Extrusion cooking gave the best performance, followed by roasting, while non-significant differences were observed between raw and pelleted bran. 3. Increasing the amount of rice bran in broiler diets resulted in significantly negative effects on growth performance. Non-significant differences were observed in mortality and dressing percentage due to different processes and concentrations of rice bran in the diet. Organ weights were significantly higher on raw and pelleted rice bran as compared to extruded and roasted bran. Liver and heart weights significantly increased with increasing contents of rice bran above 200g/kg, while pancreas weight increased with an addition of rice bran. 4. Treating the rice bran with antioxidant up to 250ppm had non-significant effects on broiler performance.     

Effect of some antibiotics as growth promoters on performance of broiler chicks fed different protein levels

This work was carried out to study the effect of different sources of dietary antibiotics (Zinc bacitracin, Flavomycin, Virginiamycin) in rations with optimal protein levels (starter phase: 23.5%, finisher phase: 20.0%) and low protein levels (starter phase: 19.6%, finisher phase: 17.0%) on broiler performance with 8 groups of 75 broiler each. The supplement of diets, containing the optimal and low protein level, with antibiotics increased the body weight after 7 weeks of age and improved the feed conversion as compared with control groups. Virginiamycin was superior in increasing body weights after 7 weeks of age and in improving the feed conversion with rations containing low protein level when compared with zinc bacitracin and Flavomycin. When broiler rations, low in the protein content, were supplemented with antibiotics, they could not substitute the difference in optimal protein level. Antibiotics supplementation increased the value of improvement in production efficiency and this was more pronounced with Virginiamycin.     

Metabolic and economic efficiency of broiler chicks as affected by dietary protein levels.

1. An experiment was designed to determine if decreasing excess amino acids in the diets of chicks would improve metabolic efficiency, as indicated by growth rate and food efficiency. 2. Semi-purified diets were fed with crude protein contents of 180 or 230 g/kg. The sources of protein were maize gluten meal, groundnut meal, sesame meal or soya-bean meal. Crystalline amino acids were supplemented to meet all amino acid requirements. 3. The dietary crude protein content had no statistically significant effect on weight gain or food consumption. The probability that the higher protein improved gain per food was 0.06. Protein source had a significant effect on all the responses measured. 4. Decreased concentrations of excess amino acids in chick diets had no favourable effects on weight gain or gain per food. Lower protein diets were more expensive per unit of gain.     

纤维素酶对肉鸡生产性能和营养物质消化利用率的影响

研究添加不同水平纤维素酶对肉鸡生产性能和营养物质消化利用率的影响,表明加入纤维素酶可提高饲料表观消化率、蛋白质利用率、能量利用率和代谢能值,低能饲料较高能饲料显著;加入纤维素酶可提高肉鸡的增重和饲料利用率,减少饲料消耗;为达到最佳的增重,低能组10~18日龄加纤维素酶0.3%,19~40日龄加纤维素酶0.2%为宜;高能组均加纤维素酶0.2%;为达到较好的料肉比,低能组和高能组均以加纤维素酶0.3%为宜。     

Effect of growth promoters on monensin toxicity in broiler chicks 1

1. An experiment was carried out with male broiler chicks to evaluate the combined effect of monensin (150 mg/kg) and the growth promoters (GPs) Zn bacitracin (BAC, 50 mg/kg), virginiamycim (VIR, 25 mg/kg) and avoparcin (AVO, 20 mg/kg) fed from 7 to 28 d of age on performance, utilisation of dietary nutrients, yield of defeathered eviscerated carcases (DEC) and size of various organs. The effect of the GPs in the monensin‐unsupplemented diets fed up to 49 d of age on performance and carcase was also determined.

2. Monensin significantly (P < 0.05) depressed food intake, weight gain and food efficiency from 7 to 28 d of age. None of the GPs was able to counteract these effects. However, AVO slightly ameliorated them. AVO also significantly increased food intake and improved gain and food efficiency during 7 to 28, but not 28 to 49 or 7 to 49 d of age. VIR and BAC did not affect performance in either age period.

3. Monensin did not affect the utilisation of dietary dry matter, fat or energy, but it significantly decreased nitrogen utilisation. AVO improved nitrogen and fat utilisation and increased dietary AME_n content. AME_n was also increased by VIR. The utilisation of these nutrients was not affected by the interactions between monensin and the GPs.

4. Monensin did not affect yield of the DEC or the relative liver size at 31 d of age. It significantly increased the relative length of the small intestine (SI) and decreased its specific weight. AVO significantly increased yield at 31, but not at 53 d of age. BAC and VIR did not affect this variable. AVO and VIR, but not BAC, at both age periods reduced, at times significantly, the size, length and specific weight of the SI.

5. Our conclusions: BAC, VIR and AVO do not counteract the toxic effect of monensin. The effect of GPs in improving performance decreases and even disappears with age, while their effect in reducing the size of the SI is still evident in 49‐d‐old birds.     

Effect of dietary palmitic acid on broiler chicks fed on various concentrations of calcium.

1. The effect of dietary palmitic acid on body weight and bone-ash of chicks fed three concentrations of calcium was studied in a 2 X 3 factorial design (0 and 10% palmitic acid, 0.4, 0.7 and 1.0% calcium). 2. Body weight of chick not influenced by the calcium concentration when palmitic acid was not included in the diet. 3. When 10% palmitic acid was included the body weight of chicks fed 0.4 and 0.7% calcium was lower (P less than 0.01) than for the other groups. 4. Bone-ash was lower (P less than 0.01) for chicks fed 0.4% calcium than for the other two calcium concentrations when palmitic acid was not added and palmitic acid at 10% of the diet reduced bone-ash of the chicks fed 0.4 and 0.7% calcium (P less than 0.01).     

Effect of ochratoxin A on broiler chicks challenged with Salmonella gallinarum

1. A study was conducted to evaluate the effects of ochratoxin A (OA) on broiler chicks challenged with Salmonella gallinarum. 2. One hundred and seventy-six 1-d-old broiler chicks were divided into two groups of 88 chicks each, with one group fed on a control mash diet and the other given a mash diet containing 2 ppm OA. On d 14, each group was further subdivided into two groups with one group infected with S. gallinarum and the other uninfected. 3. Following S. gallinarum inoculation on d 14, 4 birds from each group were killed at 1, 2, 3, 5, 7, 10, 14 and 21 d post inoculation. 4. S. gallinarum infection caused dullness, depression, weakness, increased thirst, droopy wings, ruffled feathers and greenish-yellow diarrhoea. S. gallinarum infection in the absence of OA caused 11.5% mortality which increased to 28.8% in the presence of OA. 5. Decreased body weight and reduced feed intake were observed in chicks fed on the diet containing OA. S. gallinarum infection also reduced the body weights of chicks, with the effects being more marked in chicks receiving OA. The OA diet led to increased serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, uric acid and creatinine, and decreased levels of total proteins, albumin, globulins, calcium and phosphorus. S. gallinarum infection did not cause significant alteration in any of the serum biochemical parameters. 6. Mortality and the severity of S. gallinarum infection in broiler chicks were increased by the presence of OA in the diet.     

不同生物素添加水平对肉仔鸡生长性能、血清生理生化指标和机体免疫功能的影响

生物素作为一种非常重要的水溶性维生素，以梭化酶的形式参与碳水化合物、脂肪和蛋白质三大营养物质代谢。许多年以来，人们普遍认为在猪和家禽日粮中不需要额外添加生物素就能满足其需要，究其原因主要有两个方面:一是生物素在饲料原料中广泛存在;二是肠道微生物可合成生物素。在现代化饲养条件下，在一些畜禽农场发现病例，表现为特定的临床症状，当添加生物素时，其症状得到改善。因此，营养学家们不得不重新审视生物素在畜禽日粮中的作用。本试验以肉仔鸡为试验动物，旨在系统研究生物素对肉仔鸡生长性能、血清生理生化指标和机体免疫功…     

Effects of different sources and levels of dietary chromium supplementation on performance of broiler chicks

The current experiment was carried out to evaluate the effect of different dietary chromium supplementation sources, chromium oxide (Cr₂O₃), chromium methionine (Cr‐Met), or chromium yeast (Cr‐yeast), at different levels each (500 or 1,000 ppb) on growth performance, physiological traits, and carcass characteristics of broiler chicks. A total of 490 seven‐day‐old Arbor Acres chicks were randomly distributed into 7 experimental groups each in 10 replicates of 7 birds each. The groups were control, 500 ppb Cr₂O₃, 1,000 ppb Cr₂O₃, 500 ppb Cr‐Met, 1,000 ppb Cr‐Met, 500 ppb Cr‐yeast, and 1,000 ppb Cr‐yeast. The results showed significant superiority of the organic chromium sources (Cr‐Met or Cr‐yeast) concerning body weight and weight gain, the group supplemented with 1,000 ppb Cr‐yeast consumed the lowest feed (3,185 g) and had the best feed conversion ratio (1.60) compared to the control (1.73). The chromium treatments recorded significantly better protein and lipid profile, antioxidant status, and immunological parameters than the control group. Similarly, dietary chromium supplementation increased carcass yield and decreased intestinal pathogenic bacteria. In conclusion, supplementing broiler diets with organic chromium sources at 1,000 ppb promotes growth performance, physiological traits, and carcass characteristics; such chromium treatments enhanced the antioxidant status and immunity levels of broilers.     

Effects of growth hormone on tissue metabolism in broiler chicks.

1. The effect of bovine growth hormone (GH) on cartilage, liver, muscle, pancreas and spleen has been investigated. 2. Tissue RNA was elevated in the liver, muscle and spleen of the GH-treated chicks while uptake of radioactive phosphate into RNA was stimulated for both liver and spleen. 3. The GH-treated chicks had an increased cartilage protein content together with a higher rate of incorporation of 14C-methionine pancreatic protein.     

Effect of immunosuppression with cyclophosphamide, cyclosporin, or dexamethasone on Salmonella colonization of broiler chicks

One-day-old broiler chicks were divided into four groups: untreated controls and three groups treated with the immunosuppressive drugs cyclophosphamide, cyclosporin, or dexamethasone on days 1-4 of age. On day 5, all groups were challenged orally with 10(4) Salmonella typhimurium. Suppression of immunocompetency was demonstrated in the treatment groups by significant decrease (P less than 0.05) in weights of bursas of Fabricius, and diminished mitogen-induced T and B lymphocyte blastogenesis and cutaneous basophil hypersensitivity responses. There were no significant differences among the four groups in the number of Salmonella in the cecal contents or in the number of cecal-culture-positive chicks on day 10 post-challenge at 15 days of age. Results indicated that impairment of B or T lymphocyte responses had little influence on the resistance of young chicks to Salmonella cecal colonization.     

小麦型基础日粮添加木聚糖酶对肉仔鸡生长性能的影响

玉米是饲喂肉鸡常用的能量原料,由于玉米的相对紧缺,其他农产品如小麦将成为玉米的代替品.小麦的能量略低于玉米,但蛋白质及各种氨基酸的含量远高于玉米.     

Effect of species-specific sound stimulation on the development and hatching of broiler chicks

1. Previous research has reported that chicken embryos develop a functionary auditory system during incubation and that prenatal sound may play an important role in embryo development and alter the hatch time. In this study the effects of prenatal auditory stimulation on hatch process, hatch performance, the development of embryo and blood parameters were investigated.

2. Four batches of Ross 308 broiler breeder eggs were incubated either in control or in sound-stimulated groups. The sound-stimulated embryos were exposed to a discontinuous sound of species-specific calls by means of a speaker at 72 dB for 16 h a day: maternal calls from d 10 to d 19 of incubation time and embryo/chick calls from d 19 until hatching. The species-specific sound was excluded from the control group.

3. The onset of hatch was delayed in the sound-stimulated group compared to the controls. This was also supported by comparison of the exact hatching time of individual focal chicks within the two groups. However, the sound-stimulated embryos had a lower hatchability than the control group, mainly due to significantly increased numbers of late deaths.

4. The embryos exhibited a similar growth pattern between the sound-stimulated group and the control group. Although sound exposure decreased body weight at d 16, no consistent effect of sound on body weight at incubation stage was observed. Species-specific sound stimulation also had no impact on chick quality, blood values and plasma corticosterone concentrations during hatch.     

日粮中复合添加剂水平与肉仔鸡生产性能关系的研究

以 1日龄、健壮的爱维茵肉仔鸡 6 30只 (公母各半 )为试验动物 ,应用肉鸡用复合维生素、复合微量元素和复合生物活性物质添加剂为试验因素 ,采用 3因子 5水平 2次通用旋转组合设计 ,平分成 2 0个组 (其中设 1个对照组 ) ,得到 15种施用水平组合及其 15种试验日粮 ,进行 7周龄饲养试验。结果表明 ,采食 15号日粮第 15～ 2 0组试鸡 ,7周龄增重最高达 2 36 8g ,料肉比最低达1.78,极显著地优于增重和料肉比均最低的对照组 17.5 2 %和 10 .10 % (P <0 .0 1) ;试验条件下 ,肉鸡增重、料肉比与 3种复合添加剂的施用水平有密切的相关关系 ,回归分析得出它们在日粮中最佳添加水平是复合维生素为 15 32 .0 7mg/kg、复合微量元素为 3796 .92mg/kg和复合生物活性物质为16 2 3.32mg/kg。     

Sarcoid granuloma-like lesions in the lungs of broiler chicks.

Sarcoid granuloma-like lesions were observed in the lungs of two broiler chicks showing depressed growth. Multinucleated giant cells in the lesions often contained foreign bodies comprising amorphous and laminated material. These were morphologically similar to Schaumann bodies found in human sarcoidosis. This is the first report of sarcoid granuloma-like lesions and Schaumann body-like material in chickens.