我国黄羽肉鸡发展现状与对策

1黄羽肉鸡的特点与选育进展 　　黄羽肉鸡按其生长发育的快慢可分为快大型、中速型和优质型三种。快大型黄鸡 50～ 60 d即可上市,生长性能和生产效率高,肉质、肉味、羽色方面略有不足,脚稍粗大,但生产成本低。中速型黄鸡体型外貌、羽色和肉质肉味较好,销路大,价格适中。而优质型黄鸡是在地方鸡种保存、整理和利用的基础上培育起来的小型鸡种,脚细而黄,肉味鲜美, 110日龄左右体重达 1.1～ 1.3千克,售价较高。 　　为了充分、合理、有效利用地方鸡种资源,逐步建立优质鸡的繁育、生产体系,早在 1980年,中国农科院畜牧所、江苏省家…     

Performance of early and late feathering broiler breeder females with different feeding regimens.

1. Growth, reproductive characteristics and immunocompetence were evaluated in a line of broiler breeder females segregating at the sex-linked feathering locus when maintained on three feeding regimens with two forms of food in a factorial design. 2. Long-term obesity but not short-term weight gain had deleterious consequences for reproductive characteristics, response to sheep red blood cell antigen, resistance to Escherichia coli and livability. 3. Reproductive performance of early feathering females was superior to that of late feathering ones. Differences were attributed to an association between the allele for late feathering and an endogenous viral locus ev21, which encodes for avian leucosis virus. 4. Reproductive performance of breeders fed crumbles was superior to that of breeders fed a combination of crumbles and fines.     

亚硒酸钠饲养肉仔鸡试验

迄今 ,已有大量的国内外研究结果表明 ,日粮中硒缺乏或者不足 ,对畜牧业会造成极为严重的影响。我国不少地区因缺硒导致畜禽生产性能降低或者死亡。江西亦为硒缺乏区 ,据有关资料所载 ,江西省猪肝硒平均水平为０．５７９５±０．２６５３×１０-６（干重） ,并且有部分样品的含硒量低于０．２０×１０-６。数据表明 ,江西省大部分县市处于缺硒病发病的临界状态。有的县市还存在严重缺硒的局部地区。为了考察实际生产条件下硒的应用效果 ,笔者于１９９９ -０１作了肉仔鸡补硒试验。１试验材料亚硒酸钠（分析纯）———上海化学试剂采购供应站…     

Meat quality in broilers affected with inflammation of the feather follicles

Broilers with feather follicle inflammation and birds free of this disorder were selected from the broiler chickens kept on plastic (bralen-)coated metallic slats. Both groups of broilers were killed on a sanitary slaughter line and the samples of breast and thigh muscles were analyzed for the basic composition and characteristics of the metabolism of nitrogenous and lipidic components. The content of individual amino acids in the muscles and the proportion of fatty acids in the intramuscular fat of broilers were determined for the evaluation of nutritive value. The samples of the affected spots of skin and samples of organs (liver) were subjected to microbiological examination. The resultant finding represented the common mesophilous microflora. No substantial statistically significant differences in chemical characteristics were found between the two groups. It follows from the results that the inflammation of feather follicles is a local skin disorder with no effect on the quality of the meat.     

Broiler growth and feeding behaviour in three different lighting regimes

1. Female broiler chicks reared in a 12‐h photoperiod which included a simulated “dawn” and “dusk” grew slightly faster than those reared in a 12‐h photoperiod of uniform light and others kept in continuous light.

2. This was apparently because the chicks subjected to dawn and dusk ate more food than those subjected to 12‐h uniform light and converted food more efficiently than those in continuous light.     

不同来源白色念珠菌的基因型及耐药性分析

为了研究不同来源白色念珠菌的基因型及耐药性情况,试验对患病鸡、鸭、鹅进行白色念珠菌的分离,用特异性引物扩增分离株的25S rDNA分析其基因型,用抗真菌药物伊曲康唑、制霉菌素、两性霉素B等对分离株进行耐药性分析。结果显示：从鸡、鸭、鹅中分离得到三株白色念珠菌CaJ、CaY和CaE,其基因型分别为 A型、A型和B型,耐药性试验结果显示三株分离株对制霉菌素和两性霉素B均表现出了较高的敏感性,但对其它药物表现出不同程度的耐药性。说明部分药物临床中可能使用过多,来自不同家禽的白色念珠菌在耐药性方面有所不同。     

Longitudinal development of kinematics in shetland ponies and the influence of feeding and training regimes

Nowadays, ponies are used more and more for competitive equine sports, driving and racing. The locomotor performance of ponies, however, has been evaluated in only a few kinematic and kinetic studies. To compare the longitudinal development of locomotor characteristics in the pony to the same process in the horse, the kinematics of 23 Shetland ponies were recorded at the trot on a treadmill (3 m/s) at ages 4 and 30 months using a modified CODA-3 apparatus. Furthermore, the influence of specific feeding and training regimes on this development was evaluated. It appeared that stride and stance duration increased with age, but the swing duration and pro/retraction range were similar at foal and mature age. Fore- and hindlimb maximal joint flexion at swing was larger in the mature ponies compared to foals. The elbow and shoulder joint were kept in a more extended position and the stifle joint more flexed, while scapula and pelvis were kept in a more vertical position. These effects are similar to those found in horses. The majority of both temporal and angular kinematic variables correlated significantly between foals and mature ponies. Ponies that were restricted in their feeding, resulting in a low body condition score, demonstrated a flatter gait than ponies fed ad lib (4 cm more height, 60 kg more weight), which trotted at the same velocity with significantly more joint flexion. Extra sprint training on top of free paddock exercise did not significantly influence the longitudinal development of kinematics. From these data, it can be concluded that the longitudinal development of locomotor characteristics in ponies is similar to that in horses. Fatter animals show a more animated gait, while extra sprint training added to free paddock exercise has no detectable effect on the development of kinematics. Aside from training or feeding regimes, in the Shetland pony breed, it appears possible to recognise 'good movers' at a young age.     

择食饲喂对肉鸡胴体品质和胃肠道发育的影响

试验研究择食饲喂对肉鸡胴体品质、胃肠道发育的影响。144羽22日龄艾维茵(Avian)肉鸡随机分成3个处理,每个处理4重复,每重复12羽,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择食饲喂玉米+浓缩料可显著促进肉鸡胃肠道发育(P<0.05),改善肉鸡的健康状况;②择食饲喂对肉鸡胴体品质的影响差异不显著(P>0.05),但择食饲喂玉米组能蛋比较高,腹脂率偏高。     

Effects of in ovo feeding with glycerol for broilers

The objective was to evaluate the effect of in ovo feeding with glycerol on post‐hatch development in broiler chicks. A total of 408 fertile eggs were divided into six experimental groups consisting of five 0.9% saline solutions containing various concentrations of glycerol (12.5, 25.0, 37.5 and 50.0 nmol/ml), and a placebo group (inoculation with saline only) and a control group (without inoculation). Inoculations were performed at 17 days of incubation for the evaluation of hatchability, embryo mortality, body and viscera weights, intestinal epithelium morphometry, blood glucose and liver glycerol kinase activity of chicks at hatching. Inoculation of solutions containing glycerol did not influence body weight at hatching and relative weights of liver, pancreas, intestine and breast. There was a quadratic effect of glycerol levels on the weights of yolk residue and gizzard and on blood glucose, and an increasing linear effect on spleen and heart weights. Higher duodenum and ileum villous height and deeper jejunum and ileum crypts were obtained with 50.0 nmol/ml of glycerol. A linear increasing effect was also observed in liver glycerol kinase activity; however, lower blood glucose was observed with 37.5 and 50 nmol/ml of glycerol. It is therefore concluded that glycerol may be used at doses of 25 nmol/ml as a substrate in in ovo feeding of broiler chickens. However, further studies must be conducted not only to establish an optimal dose but also to evaluate the combination of this substrate with other nutrients used in the in ovo feeding.     

Effects of different lighting regimes on diurnal feeding patterns of the domestic fowl

1. Male hybrid chicks were, from hatching, subjected to either a 12‐h photoperiod with uniform light intensity or a 12‐h photoperiod with a simulated “dawn” and “dusk” or to continuous light.

2. At 10 weeks of age the birds exposed to “dawn” and “dusk” were significantly heavier than those exposed to 12 h uniform illumination and these were heavier than those in continuous light.

3. From 15 to 25 weeks of age the birds in continuous light showed a marked diurnal rhythm in food intake, eating most in the period corresponding to normal daytime, while all birds subjected to 12‐h photo‐periods ate most at the end of the day, apparently having learnt to anticipate when their day would end.

4. When the birds subjected to continuous light were given one of the two 12‐h photoperiods, those given 12 h of uniform light intensity started by eating most food in the mornings, but later ate more towards the end of the day, while those with the “dawn” and “dusk”, ate more food at the end of the day during most of the 20‐d experimental period.

5. It is concluded that the birds preferred to eat most at the end of the day, probably to ensure adequate stores of food in the crop during the night. However, it was necessary for them to learn when their day would end, and this they did much sooner with the presence of a “dusk” than without it.

6. It is suggested that the difference in growth rate among the three treatments can be accounted for by differences in the efficiency of food conversion and also by differences in food intake.     

籽粒苋饲喂肉鸡试验初报

通过对育肥肉鸡进行籽粒苋牧草的饲喂试验,结果得出肉鸡适口性好、增重快,试验组日增重高于对照组15.22%(P<0.01),差异极显著,经济效益明显。     

不同饲养方式对AA肉鸡生产性能和经济效益的影响

本试验主要研究不同饲养方式对AA肉鸡生产性能和经济效益的影响。试验选取同批次4周龄AA肉鸡100只,随机分为2组,每组5个重复,每个重复10只,两组AA肉鸡个体情况无显著差异(P>0.05),对照组进行生态散养,试验组进行笼养,试验结束后对两组AA肉鸡的生产性能和经济效益进行分析。结果表明,试验组AA肉鸡总增重、日增重和日均采食量均显著高于对照组(P<0.05);试验组AA肉鸡料肉比显著低于对照组(P<0.05)。从增重情况来看,笼养AA肉鸡更具有经济价值,且笼养方式占地面积小,饲养密度大,非常适合较大密度的集中饲养。但生态散养AA肉鸡耗料少,能节省一定的饲料费用,再加上生态散养AA肉鸡的肉质、口感和营养等方面都比笼养AA肉鸡更符合市场需求。因此,在本试验条件下,作者建议大规模养殖户采用笼养方式,不仅便于管理,而且增重较多,总体经济效益较好,而小规模饲养AA肉鸡的养殖户建议生态散养,提高单只质量,增加单产来提高总的经济收入。     

蚯蚓渣饲喂肉鸡的消化代谢试验

为了更好开发蚯蚓渣这一饲料资源．本试验分析了蚯蚓渣的常规营养成分和氨基酸含量．并采用全收粪套算法测定了肉鸡对蚯蚓渣主要养分的代谢率。结果表明：蚯蚓渣粗蛋白质含量高达56．79％．仅次于秘鲁鱼粉,优于国产鱼粉和优质豆粕;氨基酸种类比较全面,必需氨基酸含量高,其中蛋氨酸含量为1．8％．高于进口鱼粉．赖氨酸含量为3．17％。高于一般鱼粉和优质豆粕。蚯蚓渣干物质中表观化谢能为14．16MJ／kg．蛋白质表观代谢率为96．04％．是一种营养价值很高的畜禽蛋白质饲料原料．     

白羽肉鸡前期饲养管理的误区

随着畜禽养殖行业的发展,白羽肉鸡的养殖量也显并增加,保证肉鸡养殖户的利润主要取决于肉鸡的成活率、出栏重量和料肉比等因素,很多养殖户在饲养管理中存在着很多误区,导致白羽肉鸩成活率很低,难以赚取利润.     

The effect of thermal environment on the digestion of broilers

Two experiments were conducted to determine the effect of thermal environment on the digestion of broilers. In both experiments the birds were exposed to three temperatures: 5, 21, and 32° C, and relative humidity was maintained at 60%. In experiment one, the amount of chyme in the whole digestive tract was decreased by the cold environment (5° C, 60% relative humidity) and increased by hot environment (32° C, 60% relative humidity), compared with control environment (20° C, 60% relative humidity). The expelling of digesta from the crop or small intestine was suppressed by high temperature (32° C) (p < 0.01). In experiment two, the activities of trypsin, chymotrypsin, and amylase were affected significantly by different environmental temperatures (p < 0.01). Compared to normal environment, the activities of the three kinds of enzymes in intestinal juice were decreased by the hot environment: trypsin (p < 0.01), chymotrypsin (p < 0.05), and amylase (p < 0.01), respectively. The activities of the three kinds of digestive enzyme were not influenced by the cold environment.     

Effect of feeding different sources of selenium on growth performance and antioxidant status of broilers

ABSTRACT

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0–35 d broiler chicken diets.

2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source.

3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0–35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001).

4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.     

塑料大棚饲养肉鸡的利与弊

１大棚养鸡的好处１ １投资少、成本低、见效快建一个２００ｍ２ 的塑料大棚投资不足２０００元 ,每只鸡占用一元钱 ,正常情况下养一批肉鸡就能收回成本 ,而建造同样面积的普通鸡舍需要一万多元 ,每只鸡占用六元钱 ,其投资很长时间才能收回。建一个大棚两天就可完工 ,五天就能投入使用 ,而一栋鸡舍需要５～７ｄ才能建成 ,半个月以后才能使用。１ ２利用阳光取暖、降低能耗塑料大棚上面覆盖的草苫子是活动的 ,白天有太阳的时候可以卷起来 ,让阳光直接照射 ,提高棚内温度 ,下午落日时再放下盖严以利保温 ,这样可以大大降低能耗 ,节约燃料费用 …