噪声对AA鸡生长发育的影响

本试验探讨了噪声对AA鸡生长以及血液生理生化指标的影响。供试鸡为100只15日龄的AA鸡，把其按交叉分组法分为四组（1个对照组和3个试验组），对照组不给噪声，试验组（A、B、C）组分别给予70分贝、80分贝、90分贝的噪声，试验期为30天。结果表明，噪声能引起：增重显著减缓，90分贝组鸡增重与对照组差异显著；屠宰率、全净膛率显著降低，80分贝，90分贝组屠宰率与对照组差异显著，90分贝组全净膛率与对照组差异显著：甲状腺素浓度A、B、C组与对照组相比，依次降低，且试验组与对照组差异显著。     

噪声对AA鸡生长发育的影响

本试验探讨了噪声对AA鸡生长以及血液生理生化指标的影响。供试鸡为100只15日龄的AA鸡，把其按交叉分组法分为四组(1个对照组和3个试验组)，对照组不给噪声，试验组(A、B、C)组分别给予70分贝、80分贝、90分贝的噪声，试验期为30天。结果表明，噪声能引起增重显著减缓，90分贝组鸡增重与对照组差异显著；屠宰率、全净膛率显著降低，80分贝，90分贝组屠宰率与对照组差异显著，90分贝组全净膛率与对照组差异显著甲状腺素浓度A、B、C组与对照组相比，依次降低，且试验组与对照组差异显著。     

早期数量限饲对肉仔鸡生长性能和胴体特性的影响

试验研究了早期数量限饲对肉仔鸡生长性能和胴体品质的影响。200只8日龄艾维茵肉仔鸡被随机分成4组,每组五个重复,每重复10只鸡。对照组基础饲粮根据NRC营养水平配制,试验组肉仔鸡从8日龄开始喂料量分别为对照组的90%、80%和70%,限饲1周后各组恢复自由采食。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(P<0.05);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(P>0.05);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(P>0.05);5、6、7周及2～7周各组在体重、日增重、日采食量和饲料转化率等方面都无显著差异(P>0.05)。早期数量限饲对肉仔鸡胴体特性没有显著影响(P>0.05)。     

Collagen content and architecture of the pectoralis muscle in male chicks and broilers reared under various nutritional conditions

Varying chicken growth rates were induced with different nutritional regimes, and the collagen content and architecture of M. pectoralis (PT) were compared among 21‐day‐old chicks and broilers at 80 or 95 days of age. The percentage of muscle weight to live weight was higher in rapid growing chicks (8.4%) than slow growing chicks (6.3%). The 80‐day‐old broilers engaged in compensatory growth after the early slow growth period producing PT muscle at 11% of live weight. The 80‐ and 95‐day‐old chicks with restricted late growth after an early rapid growth period showed PT weight at 8% and 9% of live weight, respectively. Collagen content of the PT muscle markedly decreased from the chicks to the broilers. The collagen concentration was higher in the late‐growth restricted broilers (1.67–1.88 mg/g) than the compensatory growth broilers (1.01–1.10 mg/g). Collagen concentration did not differ between the rapid and slow growing chicks (2.72 and 2.94 mg/g). Scanning electron micrographs showed thick and thin perimysia, and honeycomb endomysia. In the perimysia, a stack layer of collagen platelets and a reticular layer of collagen fiber cords were distinguished and collagen baskets of adipocytes were observed. The perimysial collagen fibers became thicker during growth of the chicks to broilers. However, in the late‐growth restricted broilers, the perimysial collagen fibers seemed to have retarded development compared with the compensatory growth birds. The PT muscle of chickens develops optimally when body growth is enhanced. The PT muscle of the compensatory growth broilers had improved collagen architecture regardless of the marked decrease in collagen content.     

Initial research on the use of mixed corn grain and stalk silage in broiler fattening

The suitability of a corn and cob maize silage (CCM) as a component rich in energy in the fattening ration was investigated in a growth experiment with male broilers. The CCM silage with a dry matter content of 60.2% contained the following substances determining its value (per 1 kg dry matter of the feed): 102 g crude protein, 61 g crude fibre and 682 energetic feed units for chickens (EFUc). CCM silage was either fed as a component of a feed mixture consisting of 70.5% CCM silage and 29.5% protein concentrate (all values of original substance) or both components of the ration were fed to broilers separately. The protein concentrate was composed as follows (values per kg): 650 g soybean oilmeal, 110 g fishmeal, 85 g tankage from rendering plants, 55 g torula yeast, 70 g mineral mixture and 30 g of a mixture of biologically active substances. The broilers of the control group received commercial fattening feed for broilers with coarse maize meal as cereal component. The feed mixture with CCM silage and separate CCM silage were accepted readily. When CCM silage and protein concentrate were offered alternatively, the same amount of CCM silage was consumed but 8% less protein concentrate. The broilers fed with CCM silage plus protein concentrate reached 96-97% of the live weight of the control animals (1.952 g/animal, 49th day), which received conventional feed, although their net energy intake was 10% lower. This proves a more favourable net energy expenditure for the test groups fed with CCM silage.     

AA肉鸡和北京油鸡早期消化器官发育规律研究

本试验旨在比较AA肉鸡和北京油鸡在胃肠道消化生理上的差异.选择1日龄雄性AA肉鸡和北京油鸡各50只,每个品种为1个处理,2个处理的日粮和饲养管理一致,每个处理5个重复,每个重复10只鸡.试验期28 d.在0、7、14、21、28日龄,每个品种分别选择10只鸡屠宰,测定其体重、肝脏、胰腺、腺胃、肌胃、小肠及小肠各段的重量...     

The energy and protein concentration of broiler rations in Cuba. 3. Male broilers in the summer

A total of 1,900 male broilers of the variety White Plymouth Rock was tested with 4 energy concentrations (10.5, 11.5, 12.6 and 13.6 MJ metabolizable energy/kg) and 4 protein concentrations (15.0, 17.5, 20.0 and 22.5% CP) in their first 56 days of life in 16 test groups. The animals were kept in cages and were directly exposed to the natural Cuban summer temperatures from their 15th day of life onwards. As every test group was run with 6 repetitions, the results could be variance analytically calculated. In a comparison of the behaviour of the male animals in winter and in summer it can be stated that the animals took in between 3.4 and 25% more feed in winter than in summer. In general, a lower body protein and body fat amount could be found in all test groups in summer compared to that in winter. Feed expenditure and the utilization of energy and protein were not as good as in winter. It could be shown that both maximum live weight and live weight gain can be achieved in the 2nd fattening period in the Cuban summer if rations containing 12.6 MJ metabolizable energy and 20% CP are fed in a one-phase feeding system.     

乳酸菌素对肉鸡血清生化指标和抗氧化功能的影响

本试验旨在探讨乳酸菌素对肉鸡血清生化指标和抗氧化功能的影响。300只1日龄肉鸡随机分为5组,每组4个重复,每个重复15只。Ⅰ组为空白对照组,饲喂基础饲粮;Ⅱ组为抗生素对照组;Ⅲ、Ⅳ、Ⅴ组分别饲喂在基础饲粮中添加50、100、200 mg/kg乳酸菌素的试验饲粮。试验期70 d,分别在肉鸡28日龄和70日龄时采样,计算料重比,并检测各组中血液生化指标和抗氧化功能各项指标。结果表明:1)与Ⅰ组比较,试验1～28 dⅡ～Ⅴ组肉鸡增重显著升高(P<0.05),料重比显著降低(P<0.05);1～70 dⅡ组和Ⅳ组肉鸡增重显著升高(P<0.05),Ⅱ～Ⅴ组料重比显著降低(P<0.05),Ⅳ组最低,显著低于其他各组(P<0.05),Ⅱ、Ⅲ、Ⅴ组之间差异不显著(P>0.05)。2)各组肉鸡血清尿素氮含量无显著差异(P>0.05)。Ⅱ～Ⅴ组28日龄肉鸡血清总胆固醇含量和70日龄肉鸡血清碱性磷酸酶活性均极显著或显著高于Ⅰ组(P<0.01或P<0.05);Ⅱ组和Ⅳ组28日龄肉鸡血清总蛋白含量均显著高于Ⅰ组(P<0.05);各组70日龄肉鸡血清总胆固醇和总蛋白含量均无显著差异(P>0.05)。Ⅱ、Ⅲ、Ⅳ、Ⅴ组之间上述各血清生化指标均差异不显著(P>0.05)。3)28日龄时,Ⅱ组和Ⅳ组肉鸡血清超氧化物歧化酶(SOD)活性均显著高于Ⅰ组和Ⅴ组(P<0.05),但与Ⅲ组差异不显著(P>0.05);Ⅱ～Ⅴ组肉鸡血清总抗氧化能力(T-AOC)均极显著高于Ⅰ组(P<0.01),但组间差异不显著(P>0.05)。70日龄时,Ⅱ～Ⅳ组肉鸡血清SOD活性和T-AOC均显著或极显著高于Ⅰ组(P<0.05或P<0.01),但组间差异不显著(P>0.05)。可见,饲粮中添加乳酸菌素可改善肉鸡生长性能,提高其抗氧化功能,以添加100 mg/kg乳酸菌素效果最佳。     

Sex differences in the effect of intermittent compared with continuous light on growth rate, testes and body weight of broilers reared under commercial conditions

The effect of intermittent light (IL) on the growth of broilers was tested under commercial conditions. One-d-old chickens were subjected to continuous light (CL) until 7 d of age and then received either CL or 7.5L:4.5D:7.5L:4.5D until 53 d. Body and testes weights were measured. At 53 d of age, the mean body weight of males was greater on IL than on CL; for females there was no difference. The testes of males on IL weighed more than those on CL. Growth of broilers was greater (P less than 0.05) at 35, 49 and 53 days of age if light was provided continuously from hatch to 7 d of age and then switched to IL than those remaining on CL during the entire periods.     

Parameters of nitrogen metabolism for male broilers of Tetra 82 descent

In several growth and N-balance experiments with male broilers of the genotype Tetra 82 the course of live weight and parameters of N-metabolism were investigated. Semi-synthetic feed mixtures of different protein concentration but equal protein quality (protein mixture: 70% soybean meal and 30% fish meal) were used in the trials. Data from N-balance investigations were reckoned up in the N-turnover model from Gebhardt (1963). The course of maximum (N-balance plus endogenous N-loss) capacity in dependence on live weight was regressive calculated. Based on this regression a possibility of calculation of efficiency depended protein and amino acid requirement for the whole fattening period in dependence on live weight, protein intake and protein quality (A.b) was illustrated.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 4. The effect of the energy level on the fattening of Camborough-type hybrid swine

Scientific feeding experiments were carried out with 5 castrated male pigs and 4 female animals of the genetic origin "Camborough" in the live weight range between 30 and 100 kg with a subdivision at 60 kg. In each test group the animals were fed individually and received rations with approximately equal contents of protein, amino acids, minerals and vitamins but different energy contents. Energy intake was adjusted to 3 levels of 100%, 85% and 70% of semi-ad-libitum intake. Apart from that, the digestibility of the feed mixtures used in the 2 fattening periods was determined. Having reached a live weight of 100 kg, 7 representative animals per group were slaughtered and a number of slaughtering parameters were registered. In all three test groups the daily live weight gain over the complete fattening period was very high (846, 819 and 778 g). Though the weight gain in group 3 with 70% of the energy supply of group 1 is significantly lower than in the other two groups, it is, however, only 70 g lower than in group 1. Consequently, the feed expenditure (2.6 kg mixed feed per kg live weight gain) in group 3 is by 20% lower than in group 1, in which the feed expenditure is 3.2 kg mixed feed per kg live weight gain. There were no significant differences on the weight gain performances and the registered carcass parameters between sows and castrated male pigs. Observed deviating tendencies are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental exposure of broiler chickens to boric acid to assess clinical signs and lesions of toxicosis.

One-day-old broiler chicks were housed on litter treated with 0, 0.9, 3.6, or 7.2 kg of boric acid per 9.3 m2 of floor space. After 15 days, average body weights were 340.7 g, 278.1 g, and 213.2 g for chickens exposed to 0, 3.6, and 7.2 kg boric acid/9.3 m2, respectively (P < or = 0.05). Feed conversion was 1.68 and 2.29 in chickens exposed to 0 and 7.2 kg boric acid/9.3 m2 (P < or = 0.05). In a second experiment, after birds ingested feed treated with 2500 and 5000 ppm of boric acid for 2 weeks, body weights were 254.8 g and 149.6 g, respectively. The chickens in the control group weighed an average of 285.0 g (P < or = 0.05). The 5000 ppm treatment group had a feed conversion of 1.70, vs. 1.45 in the controls (P < or = 0.05). A dose-related feathering abnormality was evident in treated chickens. No significant histopathologic changes were observed. Livability, weight gain, and feed conversion were not adversely affected in broilers as a result of exposure to litter treated with boric acid at recommended levels of 0.4-0.9 kg/9.3 m2.     

早期热应激对肉仔鸡后期生长发育的影响

旨在研究早期热应激对肉仔鸡后期生长发育及骨骼肌中相关信号通路基因表达的影响.本研究选取健康、体重相近的刚出壳AA肉仔鸡192只(公母各半),随机分成2组(每组4个重复,每个重复24只鸡),饲喂至3日龄时,分别给予36℃热应激处理24 h(热应激组)和正常温度(33℃)饲喂(对照组).42日龄时每个处理选取8只鸡采取血浆...     

The pathogenicity of Campylobacter jejuni as a monoinfection and as a mixed infection with Escherichia coli 078:K80 in broilers

Two week old broilers (n = 61) with a monoinfection with Campylobacter jejuni (0.5 ml of suspension containing 10(5) CFU/ml per os) showed reduced increase in weight during week 3 after infection compared to the control group. An other group of chickens (n = 31) was additionally infected with a suspension of Escherichia (E.) coli O78:K80 via drinking water from day 4 to 6 after the primary infection. This mixed infection provoked clinical signs of a disease and reduced increase in weight during the first two weeks of the experiment. Seven broilers of this group showed a fibrinous pericarditis and/or perihepatitis. Four of these chickens died. It can be concluded from the experiment that an infection with Campylobacter causes reduced weight gain and supports a systemic infection with E. coli.     

早期限饲对肉鸡肺动脉高压综合征发病率、生产性能和腹脂率的影响

采用低温诱发肉鸡肺动脉高压综合征,对比观察不同的早期限饲方法对于常温和低温条件下PHS的发病率、肉鸡生产性能和腹脂率的影响。在试验1中,限饲处理组肉鸡分别于7￣14日龄或7￣21日龄每天给料8h,对照组肉鸡全程自由采食。在试验2中,限饲组肉鸡分别于7￣14日龄给予对照组肉鸡前1d饲料消耗量的60%或80%。结果表明:早期限饲能够降低肉鸡PHS的发病率,在低温条件下尤其明显;早期限饲改善了饲料效率,同时未对肉鸡的胴体品质产生显著的影响,且适当限饲不影响肉鸡的最终上市体重。这表明早期限饲是一种有效的控制肉鸡PHS的方法,值得在实际生产中推广应用。     

Effectiveness of the use of momensin for cattle fattening

Two groups of fattened bulls (125 bulls in each group) were investigated for the effect of monensin (125-175 mg per head/day) on live weight gains and for the effectiveness of monensin administration. After 160 days of fattening, the average daily weight gain was 713 g in the control group and 800 g in the monensin-treated group (an increase by 12.2%). After 11 months of fattening the daily weight gain was 702 g in the control group and 768 g in the monensin-treated group (an increase by 9.4%). Besides the control and experimental groups, monensin was administered to 1500 head of fattened cattle on the whole. Greater differences in the daily live weight gains (higher gains in the monensin-treated animals) were recorded mainly in the period when the feed ration contained high-quality bulk feeds. When the bulls were given feeds of lower quality (mainly late in winter), the differences in the average daily live weight gains decrease and the effect of monensin treatment is not so great. Throughout the fattening period, monensin had a favourable influence on the live weight gains and its use was economically advantageous.     

Food value of field beans for chickens and evaluation of various portions with special reference to the tannin-poor sort in broiler fattening food

The investigations were carried out with varieties rich in tannin (Erfordia, Fribo) and one poor in tannin (White Flowering). The protein of the variety poorer in tannin is slightly richer in methionine and is slightly better digested. The studies on the varieties Erfordia, Fribo and White Flowering in quotas of 7.5...45% as component in the fattening feed for broilers resulted in the same fattening performance as in the control group (maize-soybean-fishmeal ration) and had no influence on the chemical composition of the body and the weight of the pancreas. All rations were isonitrogenous and isocaloric. The soybean oilmeal in the ration was replaced gradually resp. completely by the field bean coarse meal in connection with methionine supplements. The variety poorer in tannin did not have nutrition-physiologic advantages in the the growth experiment with young broiler chickens.     

日粮中添加酸制剂对肉仔鸡生长性能及肠道健康的影响

为了研究酸制剂在肉仔鸡日粮中的添加效果,试验选用126只1日龄健康AA肉仔鸡,随机分为对照组(不添加酸制剂组)和试验组(添加酸制剂),对照组饲喂基础日粮,试验组在基础日粮中添加酸制剂,试验期为49 d,分为前、中、后期(1～21、22～42和43～49日龄)。结果表明,在肉仔鸡的生产前期1～21日龄添加酸制剂有降低平均日采食量,增加平均日增重,提高21日龄末体重,降低料重比的趋势,但对22～49日龄肉仔鸡生长性能没有显著影响。添加酸制剂有提高49日龄回肠食糜中有益挥发性脂肪酸(乙酸)含量,降低有害挥发性盐基氮的趋势。因此,酸制剂能够改善肉仔鸡的肠道健康,且在肉仔鸡前期日粮中添加酸制剂对肉仔鸡生长性能的效果要优于在后期日粮中的添加效果。     

海滨锦葵块根粉对肉仔鸡生长和免疫性能的影响

 
试验以AA肉仔鸡为试验对象,分析海滨锦葵块根粉和酶制剂对其生长和免疫的影响。选取96羽1日龄AA肉仔鸡,随机分为4组。试验Ⅰ组为对照组,饲喂基础日粮,试验Ⅱ、Ⅲ、Ⅳ组分别在饲喂基础日粮基础上添加0.02%复合酶制剂,0.5%和1%海滨锦葵块根粉,试验期21 d。结果表明,与对照组和酶制剂组相比,添加海滨锦葵块根粉有提高肉仔鸡的增重的趋势,但差异不显著（P>0.05）;与对照组相比,酶制剂和海滨锦葵块根粉对肉仔鸡免疫器官指数无显著影响（P>0.05）;酶制剂组、0.5%和1%海滨锦葵块根粉组的溶菌酶活性比对照组分别提高了23.90%、3.94%和3.17%,但差异均不显著（P>0.05）;酶制剂组的肿瘤坏死因子-α含量极显著低于对照组（P<0.01）,并且显著低于1%海滨锦葵块根粉组（P<0.05）,而海滨锦葵块根粉组与对照组差异不显著（P>0.05）;酶制剂和海滨锦葵块根粉都可以减少血清中白介素6含量,但差异不显著（P>0.05）;酶制剂和海滨锦葵块根粉对新城疫疫苗抗体效价无显著影响（P>0.05）。结果提示,酶制剂和海滨锦葵块根粉对肉仔鸡的生长性能有提高趋势,酶制剂可以提高肉仔鸡免疫功能,而海滨锦葵块根粉对肉仔鸡免疫功能有一定影响。     

Field trial evaluating changes in prevalence and patterns of antimicrobial resistance among Escherichia coli and Enterococcus spp. isolated from growing broilers medicated with enrofloxacin, apramycin and amoxicillin

The present study investigates, under field conditions, the influence of antimicrobial administration on prevalence and patterns of antimicrobial resistance among Escherichia coli and Enterococcus spp. isolated from growing broilers. For this purpose, a group of 16,000 commercial broiler chickens was treated with enrofloxacin from day 1 to day 3, gentamicin from day 19 to day 21, and ampicillin from day 26 to day 28. A control group of 16,000 broilers was placed in the same controlled environment poultry house. Fecal (from both groups) and feed samples were collected at regular intervals. Few E. coli isolates were obtained from either farm environment or poultry feed samples, while enterococci were found to be ubiquitous among these samples. The frequency of resistance against most antimicrobials tested was significantly higher (P < 0.05) in E. coli isolated from broilers receiving intermittent antimicrobial pressure than that from non-medicated broilers, whereas in enterococci these differences were only observed among structurally related antimicrobial drugs and over a short period of time. By the time the broilers reached market age (33 days), several multi-resistant E. coli and enterococci were detected in the feces of the medicated group. Results suggest that antimicrobial resistance in E. coli was mainly medication-dependent, whereas among enterococci, changes observed over time were apparently influenced by factors apart from antimicrobial exposure, namely the resistance organisms previously present in farm environment and those present in feedstuffs.