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1.
1. Body weight and the weight of the digestive organs and activities of some digestive enzymes were determined from hatching to 23 d of age. 2. Relative daily growth rate peaked at 11 d of age (22% gain/d) and then decreased gradually. 3. The vitelline residue was decreased rapidly from 4.6 g at hatching to negligible values from 4 d of age. 4. Maximal allometric growth of the pancreas and small intestine was 4-fold and that of liver 2-fold greater than that of the body. 5. Activities (units/kg body weight) of the digestive enzymes measured in the pancreas and intestinal contents increased with age. In the pancreas maximal values were attained on day 8 for amylase and lipase and 11 for trypsin and chymotrypsin. In the small intestine maxima were attained on day 4 for lipase, 11 for trypsin and chymotrypsin and 17 for amylase. 6. The development of secretion of digestive enzymes in the post-hatched chick could be a limiting factor in digestion and subsequently in food intake and growth. 相似文献
2.
Storage of eggs for 14 d prior to incubation depressed hatchability by 10%. Most of the increase in embryonic mortality (64%) occurred during the first week of incubation, with a further 30% taking place during the third week. Chicks hatching from stored eggs did not show any increased incidence of physical abnormalities characteristic of vitamin deficiencies. Chicks from stored eggs showed haematological abnormalities characteristic of mild macrocytic anaemia. Such changes can result from deficiencies of folic acid or cobalamin. Biochemical and haematological data did not suggest impairments in the status of the chicks with respect to a range of other vitamins. 相似文献
3.
ABSTRACT1. The physical factors that involve artificial incubation determine embryonic growth and hatching of broiler chicks, and have important implications for the poultry production chain and chick welfare. This study explored the effects of sound exposure on incubation responses (hatching, embryonic development and chick quality).2. A 2 × 2 factorial experiment with the factors ‘sound pressure level’ (at 70 and 90 dB) and ‘species-specific vocalisations’ (at 75dB - 85dB) was performed in four experimental incubators (loaded with 90 eggs each) for eight consecutive cycles of incubation, totalling 2880 Cobb-500® broiler breeder eggs.3. Embryonic growth was not influenced by any experimental factor, but the highest sound pressure level (90 dB) led to earlier hatching, higher hatchability, better chick quality and lower weight at hatching. Additional effects of species-specific vocalisations were found at 70 dB noise, which caused early hatching and better chick quality.4. It was concluded that the loud noise found in commercial hatcheries (at 90 dB) can be beneficial. Furthermore, the presence of species-specific vocalisations could improve the hatching time and chick quality from experimental incubators (at 70 dB). However, this would not provide additional benefits in commercial hatcheries, due to the machinery noise masking them. 相似文献
4.
1. The effect of egg weight on the subsequent performance of individual growing chicks was studied. Eggs from commercial broiler breeder hens were collected at 52, 55 and 57 weeks of age and incubated. The chicks were reared for 18 d. 2. Egg weight and hatched chick weight were not affected by the age of the hens during the 52 to 57-week period, but there was a close correlation between egg weight and hatching weight, irrespective of the age of the hens (r = 0.89). Chick:egg weight ratio at hatching was about 0.71 and independent of hen age. One d after hatching, chick weights had decreased by about 1.5 g. 3. The initial high correlation between egg weight and chick weight decreased markedly during post-hatching growth, becoming insignificant 5 d after hatching. At 18 d of age, however, chicks from eggs of older hens tended to be heavier than those from younger birds. The greater 18-d weights appeared to be associated more with higher food intake during that period, than with greater egg weight. 4. It was concluded that, in individual broiler chicks, the advantage of the initially higher weight attributable to a larger egg diminishes rapidly after hatching, and the main factor affecting final body weight is food intake. 相似文献
5.
1. Body weight, the weight of digestive organs and activities of some digestive enzymes were determined from hatching to 14 d of age in meat‐ and egg‐type chickens. 2. Relative daily food intake and growth rate were much higher in meat‐than in egg‐type chickens. Relative daily food intake peaked at 30% of body weight at 3 d of age in meat‐type, and at 20% of body weight at 6 d of age in egg‐type chickens and then decreased gradually. The corresponding values for growth rate were 20 and 14%. 3. Allometric growth of the small intestine, intestinal contents and liver was greater in meat‐type chickens, but the growth of the pancreas attained a higher value in the egg‐type birds. Diminution of the vitelline residue was similar in the two breeds. 4. Pancreatic digestive enzyme activities were similar between stocks, but activities in the small intestinal contents were lower in meat‐type chickens. 5. The secretion of digestive enzymes in the newly‐hatched meat‐type chicken could be a limiting factor in digestion and, consequently, in food intake and growth. 相似文献
6.
During 65 d of storage a gradual increase in fungal activity (evaluated by CO2 production) was observed in a diet with its moisture content elevated to 136 g/kg. This activity was inhibited by supplementation of the wetted diets with either calcium propionate (3 g/kg) or Agrosil (2 g/kg). The fat content of the wetted untreated diet decreased between the 18th and the 45th d of storage from 38 to 29 g/kg. This change was prevented by the addition of either of the two fungistats. The weight gains of 7-d-old female broiler chicks fed on the wetted diets with or without the fungistats from the 18th d after their preparation for 27 d, did not differ significantly (P greater than 0.05) from those of birds fed on the unwetted diet. However, the food:gain ratio of chicks fed on the unwetted diet was significantly (P less than 0.05) better than that of chicks fed on the fungistat-free wetted diet. The results from birds fed on the fungistat-supplemented wetted diets were intermediate. It is concluded that the early stages of fungal activity (characterised by increased CO2 production, without changes or with only a slight decrease in fat content) have only a minor effect on the nutritional value of diets. 相似文献
7.
In two experiments space allowances of 0.143, 0.122, 0.105 and 0.093 m 2/bird and 0.093, 0.078, 0.064 and 0.047 m 2/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. 相似文献
8.
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. 相似文献
9.
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。 相似文献
10.
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。 相似文献
11.
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 AMEn content. AMEn 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. 相似文献
12.
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. 相似文献
13.
试验用 6 0 0只爱拔益加肉仔鸡 ,研究了在小麦部分或全部取代玉米配制的日粮中 ,添加木聚糖酶对肉仔鸡的生产性能和养分消化率的影响。试验结果表明 :小麦全部取代玉米后 ,肉仔鸡的小肠食糜粘度、耗料增重比和死淘率显著升高 ,蛋白质、脂肪、淀粉的消化率及能量的利用率均降低 ;在小麦日粮中添加木聚糖酶后 ,耗料增重比和小肠食糜粘度显著降低 (P <0 .0 5 ) ,死淘率降低 71.9% ,能量利用率和蛋白质、脂肪、淀粉的消化率显著提高 (P <0 .0 5 ) ,改善了肉仔鸡的生产性能 ,达到甚至超过玉米日粮的饲喂效果。小麦取代玉米用量的 5 0 %后 ,除小肠食糜粘度显著升高外 ,其余指标与玉米日粮的无显著差异。在小麦和玉米各半的日粮中添加木聚糖酶后 ,只有食糜粘度显著降低 ,其余指标无明显改善。 相似文献
14.
1. This research focused on the embryonic development of broiler and layer embryos. 2. Egg, embryo and yolk weights were measured and partial pressure of gases in the air cell and blood were analysed at several embryonic ages. The static stiffness of the eggshell was measured before the start of incubation and at embryonic day (ED) 18 to register the change in shell strength. Times of internal pipping (IP), external pipping (EP) and hatch were recorded. Plasma corticosterone, triiodothyronine and thyroxine concentrations were determined. 3. Relative egg weight loss was higher in layer eggs. Before ED16, layer embryos showed a slower development which was reflected in lower (relative) embryo weight, lower air cell and blood pCO(2) and higher air cell O(2). From ED16 onwards, relative growth rate accelerated in the layer strain; as a consequence the difference in relative yolk-free chick weight at hatch had disappeared between strains. 4. Differences in physiological events necessary for hatching (thyroid hormones, corticosterone, air cell pCO(2)) are most probably responsible for the observed differences in timing of pipping and hatching events between layer and broilers. 相似文献
15.
1. The effects of adding lincomycin to either the food (2.2 mg/kg) or drinking water (equivalent or 0.5 equivalent amount) of male broiler chicks were examined. 2. There were four treatments: control (no lincomycin), diet containing 2.2 mg lincomycin/kg, control diet plus drinking water containing lincomycin at concentrations calculated to provide an intake equivalent to treatment 2, and treatment 14 with lincomycin concentration reduced by half. 3. There was no significant effect of any treatment upon mortality, efficiency of food utilisation at 42 d of age, final body weights or monetary indices. 4. Analyses of breast, thigh and liver tissues, using a method with a sensitivity of 1.0 mg/kg, failed to reveal any evidence of lincomycin residues. 5. It is concluded that the use of lincomycin at 2.2 mg/kg may not be effective in improving either the biological or economic performance of the broiler chicken. 相似文献
17.
Two experiments, which differed in breeder age, strain and season, were conducted to study the influence of low-intensity, short-duration thermal stimuli during the late phase of incubation on hatchability and performance. The first experiment conducted in April–June used eggs from Cobb × Ross broiler breeders at 35–41 weeks of age and the second experiment performed in February–April used eggs from Hubbard × Cobb broiler breeders at 49–53 weeks of age. Eggs in the test group had the same physical environment as eggs in the control group except that incubation temperature was increased by 1?C for 2 h/d above the control group from 18 to 20 d of incubation (DI). The results demonstrated that thermal stimulation of 1?C for 2 h/d above control incubation temperature during 18–21DI did not have any adverse effects on hatch and post-hatch performance of broilers. In both experiments, treatment did not significantly alter the secondary sex ratio in hatched chickens, but hatch residue showed that the proportion of unhatched male embryos was significantly lower in the test groups than in the control groups. In the first experiment, thermal stimulation improved feed conversion by 1.82% compared with the control. 相似文献
18.
为了研究本交笼对肉种鸡生产性能、种蛋品质及繁殖性能的影响,试验组选择108只29周龄的健康罗斯308肉种鸡,公母比例1∶8,随机分为6笼,每组16只母鸡、2只公鸡,以同舍内"两高一低"平养模式大群为对照组,比较种鸡产蛋性能、种蛋品质、孵化性能及行为差异。结果显示:本交笼养模式下种鸡产蛋率、破蛋率有升高趋势,料蛋比呈下降趋势;与平养模式相比,本交笼养模式下肉种鸡种蛋的平均蛋重极显著提高(P<0.01),蛋形指数显著增加(P<0.05),蛋壳厚度显著增加(P<0.05),蛋壳亮度L值极显著降低(P<0.01);2种饲养模式下,肉种鸡种蛋的受精率、种蛋的孵化率及后代健雏率没有明显差异(P>0.05),但本交笼饲养肉种鸡后代雏鸡初生重显著增大(P<0.01);动物行为观察发现,种鸡在本交笼内自由舒适,分布均匀,饮水采食频率增加,不存在扎堆现象,几乎没有打斗行为,说明本交笼内动物福利水平更高。提示:肉种鸡本交笼养模式可以应用于肉种鸡生产。 相似文献
19.
A series of Japanese quail clutches was incubated, then one egg from each clutch was stimulated at a rate between 1 click/10 sec. and 1000 clicks/sec. The hatching time of the stimulated egg was recorded and compared with that of its siblings. Embryos stimulated by discrete clicks at rates of 1 1/2–60/sec. were speeded up; while those stimulated between rates of 100–500 clicks/sec. were slowed down. These results are considered as contributing towards a possible explanation of the synchronisation of hatching in this species. 相似文献
20.
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. 相似文献
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