高钙饲料引起肉种鸡种蛋孵化率下降的报告

肉种鸡产蛋期营养标准要求饲料中钙的含量为3．0～3．3％，罗斯308肉种鸡产蛋期对钙的要求更低些为2．8％。如果种鸡常期食用高钙饲料会在体内形成钙盐沉积于肾脏，阻碍尿酸盐排出，易形成输尿管结石和肾结石，严重时形成内脏痛风，甚至死亡。产蛋鸡蛋壳因钙沉积过多而增厚，对种蛋的孵化率造成严重影响。笔者在2007年1月诊断一起因种鸡食用高钙饲料而引起种蛋孵化率下降的病例，现报告如下。     

高钙饲料引起肉种鸡痛风的诊疗

某种鸡场有一栋鸡舍,3500套罗斯308肉种鸡,饲养至13周龄时,陆续出现鸡只瘫痪并不断死亡的现象,每天死亡5只至10只不等,外观表现为皮肤干瘪脱水,腿部和爪部呈暗灰色,亦有脱水现象。剖检可见皮下有白色尿酸盐,打开腹腔后,可见到肝脏表面、心包膜、肠系膜上均有白色尿酸盐沉积,严重的病例表现为内脏器官粘连在一起。     

高钙饲料引起种鸡痛风的报告

黑龙江某鸡场有一栋鸡舍，3000套AA肉种鸡在12周龄时，陆续出现鸡只瘫痪并不断死亡的现象，每天死亡5只至10只不等，外观表现为皮肤干瘪脱水，腿部和爪部呈暗灰色，也有脱水现象。剖检可见皮下有白色尿酸盐，打开腹腔后，可见到肝脏表面、心包膜、肠系膜上均有白色尿酸盐沉积，严重的病例表现为内脏器官粘连在一起。另外，在打开腿部关节后，可见腿部关节表面也有白色尿酸盐沉积。     

饲料营养对肉种鸡生产性能的影响

肉种鸡具有较好的遗传潜力,即早期快速生长率、较高的料肉比和胸肉率。遗传性能的不断提高和改进意味着需要增长趋势的生长曲线以保证有效的繁殖性能。当生长和繁殖对营养的需求较高时,其缺乏或临界缺乏的耐受性变差,容易引起种鸡超重而降低生产效率。在主要阶段比如性成熟期,营养供给和喂料的整体过程变得更加敏感。由此可见,随着遗传性能的不断提高和改进,使得较好管理鸡群的灵活窗口变窄许多。同时增加机体瘦肉体况需要更加注重改变饲料与营养物质的供给。与以前相比较,精心细致的管理同样可以取得较好的生产效率。     

我国肉种鸡产蛋日粮钙磷水平过高

现行的肉种鸡钙磷水平有问题吗? 肉种鸡日粮有很多的营养指标,其中钙磷是非常重要的指标.产蛋肉种鸡日粮中钙和磷的主要功能是形成蛋壳和维持骨骼的钙磷平衡.日粮中钙磷水平不合理(过高或过低)对种鸡及其后代的健康和生产性能有很大的负面影响.在此笔者对目前肉种鸡产蛋日粮的钙磷水平是否过高提出质疑,并着重就钙水平过高阐明观点.     

肉种鸡高生产性能和高繁殖力研究

肉鸡生产的主要目标是使鸡的巨大生长潜力最大化,从而可以获得较大的体重和较高的胸部肌肉产量。然而,这两个目标都与其繁殖力成负相关。因此,如何维持和提高肉种鸡的繁殖力已经成为我们必须面临的一项挑战。现在的问题是,肉鸡的繁殖力是否已经达到临界点,并且肉种鸡繁殖力的改变是否是不可逆转的。     

肉种鸡的限制饲养

肉种鸡是禽类生产中管理技术要求最严格的一种。生产实践中,常常由于经验不足或认识不够,出现饲养效果不理想,营养供给不足等问题,使肉种鸡生产达不到预期效果,严重影响生产性能的正常发挥。肉鸡具有生长速度快（8～9周龄即可达成年体重的80％）,脂肪沉积能力强,体格重的特性,     

饲料中添加维生素E对肉种鸡和肉仔鸡生产性能的影响

设４ 个处理组,即在肉种鸡饲粮中添加ＶＥ：０ 、２０ 、３０ 和４０ＩＵ／ｋｇ 。结果表明,饲料中添加ＶＥ 对种蛋受精率、孵化率和肉仔鸡成活率有明显影响（Ｐ＜ ０ ．０５） 。４０ＩＵ 的一组明显高于其它各组（Ｐ＜ ０ ．０５） 。种鸡产蛋率、产蛋量、肉仔鸡日增重、平均日耗料量和料重比不受饲粮ＶＥ添加量的影响（Ｐ＞ ０ ．０５） 。     

浅谈肉种鸡产蛋高峰料量

肉种鸡高峰料量直接影响产蛋高峰值和维持水平。高峰料量偏低，维持营养不足，或生产营养不足，产蛋性能不能正常发挥，持续产蛋高峰的能力下降；高峰料量过高，营养过剩，皮下脂肪增厚，双黄蛋比例增加(一般日料量每高2克/只，双黄蛋比例增1％)，鸡群持续产蛋能力下降，     

肉种鸡生产中的饲料管理

饲料对家禽生长很重要,一只肉鸡每增长0.5千克的体重,需消耗0.9~0.95千克的优质配合饲料。如果饲料质量不好,轻者导致生长缓慢,重者可能引起中毒死亡等。肉种鸡能否保持良好的均匀度和正确的体重增长反映出饲养人员管理鸡群的水平。评估肉种鸡的生产性能应综合考虑饲料成分、饲喂管理和常规管理。因此,应为父母代肉种鸡提     

Photoperiod and oviposition time in broiler breeders

1. Oviposition times were recorded for broiler breeder hens under 8-, 10-, 11-, 12-, 13-, 14- and 16-h photoperiods. 2. Mean oviposition time (MOT) was delayed relative to dawn by approximately 0.5 h for each 1-h increase in photoperiod up to 14 h, but was similar for 14- and 16-h photoperiods. However, the 0.5 h/h regression for the time when half the eggs were laid continued through to 16 h. 3. The rate of change in MOT for each 1-h increase in < or = 14-h photoperiod was similar to that reported for early and modern egg-type hybrids, but, compared with modern genotypes, time of lay itself was 1 h later than white-egg and 2.5 h later than brown-egg hybrids. 4. At photoperiods < or = 12.25 h, the number of eggs laid before dawn increased by 4-5% for each 1-h reduction in daylength.     

饲喂时间对成年肉种鸡各产蛋参数的影响

饲喂时间对成年肉种鸡的生产性能具有潜在的影响,因此十分重要。常规看来,在一天较晚的时候给肉种鸡喂料似乎对产蛋数或蛋重并无益处。然而,将饲喂时间延后或将每日的饲喂量分成多餐更频繁地饲喂,则有可能会提高蛋壳质量。但是,通过推迟饲喂时间以期提高蛋壳质量的愿望可能无法实现,尤其是对采用垫料平养的种鸡而言,这种愿望更可能无法兑现。此外,蛋壳质量的改善并不能提高孵化率,因为蛋壳厚度的增加会对蛋壳的水蒸气传导产生不利的作用。肉鸡种蛋生产者应该意识到,饲喂时间的推后可能会推迟母鸡的产蛋时间,由此就需要改变养鸡场的生产作业计划。此外,推迟饲喂时间可能会导致采食活动与其它重要生理活动(如交配和产蛋)时间的重合,这会导致种蛋受精率的下降和畸形蛋数量增加。成年肉种鸡目前的商业性饲喂是在每天较早的时候(开灯或开灯后不久)进行的,这种方法被证明是合理的,因为此时进行饲喂会对种蛋生产的其它指标产生有利的影响。然而,午后喂料未必有害,而且在需要提高蛋壳质量的情况下可能是一种应该予以考虑的方法,不过这种饲喂方法可能无法解决孵化率低下的问题。如果考虑要调整饲喂时间,那么环境条件,尤其是光照周期和环境温度,也必须一同考虑,而且饲喂时间上的任何改变都应逐渐进行,因为肉种鸡对饲喂时间的应激非常敏感。此外,饲喂方案的改变应该与生产性能参数的严密监控同时进行,这些参数包括对可入孵蛋数量、畸形及地面蛋、受精蛋比例和受精蛋孵化率。     

The effect of feeding time on shell quality and oviposition time in broiler breeders

Three experiments were performed to determine the effect of feeding time on shell quality and oviposition time in broiler breeders. Mean eggshell thickness was increased significantly by 3.5 microm (approximately 1%) per h delay in feeding time when hens were housed in individual cages. However, eggshell thickness was not significantly affected by feeding time when birds were housed on litter floors. Mean oviposition time was delayed relative to lights on by 5 min per h delay in feeding time. Egg weight was not significantly affected by feeding time, suggesting that differences in shell thickness and oviposition times were not due to increased oviducal transit times. Producers who wish to implement delayed feeding may have to turn lights on earlier than usual to compensate for delayed oviposition times.     

肉种鸡育雏育成期的管理

给刚出生的雏鸡适当的关心和照顾,会使其更加健康,进而可获得更好的生产性能。     

Modelling changes in the components of eggs from broiler breeders over time

1. Because the components of the egg differ in nutrient content, and the proportions of these components change over time, the daily intake of nutrients required to produce an egg will also change with time. Information on these relationships is essential when attempting to determine the nutrient requirements of a broiler breeder hen at different stages of lay, and in predicting performance when the hen is supplied with a given amount of food with a given nutrient composition.

2. Yolk weight is related to hen age and may be predicted using a linear-by-linear function, the coefficients of which are the same for Cobb and Ross breeders. Allometric functions may be used to predict albumen weight from yolk weight, and shell weight from the weight of the egg contents. Egg weight is given by the sum of the three components.

3. The proportion of yolk increased with advancing age whilst the proportions of albumen and shell decreased. However, at a given age, larger eggs contain proportionally more albumen. Eggs from Cobb hens had proportionately more albumen than Ross eggs towards the end of lay.

4. A stochastic population model verified that these functions accurately reflect the proportional changes in the egg components with advancing hen age and at a given age, over a range of egg weights.     

On-farm assessment of environmental enrichment for broiler breeders

1. A field experiment was conducted with commercial broiler breeder females to assess the hypothesis that the provision of bunches of string and bales of wood shavings would provide attractive environmental enrichment and improve welfare by decreasing aggression and feather damage. 2. The experiment was a randomised block factorial design conducted in a commercial flock of 21,600 female broiler breeders in 12 pens of 1800 chicks. Treatments were environmental enrichment (4 plastic coated bales of wood shavings and 50 bunches of string) from hatch (EE1) or 8 weeks of age (EE2) and a control treatment with no environmental enrichment. There were 4 replicates (rooms). 3. Bird activity was videotaped at 5, 10 and 16 weeks of age and subsequently scored for the number of birds using the perch or pecking at a bale, drinker, litter and section of the wall at 10-min intervals for 4 h throughout the photoperiod (24 times/d). Aggression was assessed by determining the number of aggressive acts in 2-min intervals during 8 periods of the day. The skin and feather condition of 25 birds in each pen were scored at 6, 12 and 18 weeks and the condition of the string bunches was scored at the end of the experiment. 4. The proportion of birds pecking the bales, wall and litter declined and the proportion pecking at the drinker and using the perch increased with age. The number of birds pecking at the bale was similar in EE1 and EE2 at 10 and 16 weeks of age. 5. The string bunches were not extensively used. The condition of the bunches of string in EE2 was worse than in EE1 at the end of the experiment. 6. The number of aggressive acts increased with age and there was no consistent difference between treatments. 7. There was an increase with age in the damage score for feathers over the back and wings and around the tail and vent but no differences between treatments.8. Provision of litter in the form of unopened bales of wood shavings was a commercially acceptable form of environmental enrichment, but there was no evidence that behavioural changes associated with feed restriction, including the prevalence of aggression, were improved.     

Genotype, dietary manipulation and food allocation affect indices of welfare in broiler breeders

1. An experiment was performed to compare the welfare of three broiler breeder genotypes (Label Rouge (LA), experimental dwarf (ER) and standard (SR)) fed on a Control or high Fibre diet. The LA birds were fed ad libitum and the other groups were reared to their recommended body weight targets. A group of standard broiler breeders was also fed a restricted amount of food, but to a lesser degree than SR, to achieve the same proportion of body weight (SE) as ER relative to ad libitum-fed dwarfs based on previous research. LA, ER, SR and SE are referred to as 'groups' in the text. 2. Welfare was assessed by comparing time budgets and heterophil-lymphocyte ratios (HL ratios) at 5, 10 and 15 weeks and immune responses at 15 weeks of age. In addition the weight and water content of the gastrointestinal tract at 4-h intervals at the end of the experiment were studied in LA and SR fed on both diets. 3. Body weights of LA, ER and SR fed on the Fibre diets were depressed and LA ate less of the Fibre than the Control diet. The coefficient of variation of body weight at 15 weeks was 7.9% in LA and similar (10.8 to 11.6%) in the other groups. 4. Drinking, litter-directed behaviour, resting and standing were affected by a group x age interaction with restricted birds showing increased drinking over time and less time spent resting compared to LA. The behaviour of ER birds was similar to SE. 5. HL ratios were within the normal biological range although all restricted-fed birds had an elevated HL ratio at 10 weeks of age relative to week 5 whereas LA birds had a reduced HL ratio at 15 weeks relative to 5 and 10 weeks of age. Immune responses were lower in ER and SE and the highest response was in SR. 6. No effects of diet were identified on behaviour, white blood cell counts or HL ratio. 7. With the exception of the crop, the dry weights of digesta in each section of the gut were similar in LA and SR birds. The results suggest that drinker-directed activity might be a substitute for foraging rather than an attempt to increase gut fill. 8. It is concluded that the replacement of standard with dwarf broiler breeders may improve the welfare of commercial flocks of broiler breeders by decreasing the degree of food restriction resulting in favourable changes in behaviour, for example, reduced 'drinker-directed' behaviour.     

管理肉种鸡的产蛋行为

法国和讲法语的北非国家是至今为止小体型、轻体重肉鸡的最大市场。许多法国种鸡育种公司正对这一需求作出反应,如肉鸡生产商Goasduff公司（一个管理出色的家族型企业,对他们的父母代鸡群定下了明确的目标）就拥有大部分小型种鸡。他们采取特殊的管理措施以取得合理的产蛋性能。