几种公鸡日粮对种鸡人工授精受精率影响

笼养种鸡人工授精技术已在多数蛋种鸡场和少数肉种鸡场得到推广应用，并获得了可观的生产效益和经济效益。但很多种鸡场人工授精的受精率不高，原因是多方面的，公鸡饲喂不适当口粮也是一个重要原因。本试验采用几种不同粗蛋白质水平、不同钙水平的口粮饲喂公鸡，观察受精率结果，寻找比较适合的笼养公鸡口粮。1材料和方法1．1材料1．1．1选择本场饲养健康的25周龄罗曼父母代褐壳蛋种鸡AJ3176羽，CD4064羽。1．1．2本场自配三种全价公鸡饲料和一种全价种鸡产蛋饲料，营养水平见表1，分别编号为1、2、3、4号。1、2、3号饲料中另外再添加维…     

肉用种鸡限饲方法的试验报告

限制饲养,是肉用种鸡生长阶段的重要技术措施之一,实施的结果如何,会直接影响整个肉用种鸡群饲养工作的成效。我们曾采用过“隔日限饲法”、“每日一次给料限饲法”,其效果均不令人满意。因而,筛选、采用最佳的限饲方法,便成为我场亟待解决的实际问题。1988年,我们在东北农学院迟继我教授的捐导下,分析了在限饲期间鸡死亡的原因,并针对以往限饲方法的弊端,设计了本试验,效果很好,现报告如下。     

不同比例代乳粉饲喂种公鸡对受精率的影响

为探讨在蛋种鸡后期公鸡饲料中添加代乳粉对提升其精液品质的作用,对蛋种鸡270日龄后的种公鸡饲料中分别为添加代乳粉0.3%、0.6%、1.0%。结果表明,种公鸡饲料中添加代乳粉有利于提升其精液品质,从而提高受精率,以添加0.6%代乳粉的效果最好。     

肉种鸡限饲方案研究进展

为改善因生长过快出现的一系列健康和繁殖问题,肉种鸡必须从早期开始限饲.限饲方案包括定量限饲和定性限饲.定量限饲可以改善肉种鸡的繁殖和健康问题,但同时会使其产生饥饿感和挫败感,出现如啄癖、过度饮水、踱步等应激性反应.理论上,定性限饲可通过增加肉种鸡采食时间和胃肠道饱感,减少这些异常反应,但目前的研究结果并不一致,具体原因尚不清楚.本文综述了各种限饲方案对肉种鸡繁殖性能的影响,并对其机理进行了分析.     

种公鸡的体重控制与限饲

过肥、过大的公鸡会导致动作迟钝,不愿运动,追逐能力差,影响精子的生成和受精。由于腿脚部负担加重,容易发生腿脚部的疾患,尤其到40周龄后更趋严重。所以,种公鸡至少从6周龄开始直至淘汰都必须进行严格的限制饲养,控制其生长发育。     

养好肉用种公鸡的技术措施

近年来,随着市场竞争的加剧,肉用种公鸡的饲养管理越来越引起人们的重视。我场饲养艾维茵种鸡多年,积累了一些经验和教训,现介绍如下: 一、肉用种公鸡的饲养目标 公鸡的外生殖器官不很发达,其成功的交配要靠较长的腿脚和平坦的胸部,使双脚可以很稳地抓紧母鸡的背部,并低贴前身将尾部弯下,便于把精液     

Effects of restricted feeding on physiological stress parameters in growing broiler breeders

1. In previous studies, a lack of agreement in measurements of plasma corticosterone concentrations and heterophil:lymphocyte (H/L) ratio as physiological indices of stress, caused by hunger and frustration in restricted-fed broiler breeders, was observed. It could be suggested that the differences between previous studies were caused by differences in duration of restriction and time of the day of the measurements. Therefore, in the present study the plasma corticosterone concentration and the H/L ratio were again determined in restricted- and ad libitum-fed growing broiler breeders, taking possible causes of disagreement between previous studies into account. In addition, we measured the daily rhythm in body temperature and heart rate, and the corticosterone responses to an acute stressor as physiological indices of stress. 2. Female broiler breeders (64 per treatment, housed in groups of 4 birds) were used in the experiment. Behaviour, baseline plasma corticosterone concentrations and H/L ratio were determined at 21 d of age (immediately after the start of food restriction), and at 42 and 63 d of age. Body temperature, heart rate and activity were measured by radiotelemetry for 36 h at 49 and 70 d of age. In addition, the plasma corticosterone response to acute stress (5 min manual restraint) was measured at 77 or 78 d of age. 3. Restricted broiler breeders had higher plasma corticosterone concentrations at 42 and 63 d of age, but no differences in H/L. ratio were found between restricted birds and unrestricted control birds. Restricted broiler breeders had a higher corticosterone response to 5 min manual restraint than unrestricted birds. Restricted birds displayed a clear day-night rhythm in body temperature, heart rate and activity whereas such a rhythm was blunted in ad libitum-fed birds. 4. It is discussed that some physiological differences (plasma corticosterone concentrations, body temperature and heart rate) between ad libitum-fed and restricted broiler breeders may have been caused by differences in metabolic rate as well as by differences in the level of stress. It is concluded that a combination of behavioural measurements and a wide range of physiological parameters should be used for the assessment of stress in growing broiler breeders.     

Welfare assessment of broiler breeders that are food restricted after peak rate of lay

1. Broiler breeder females were reared on one of three growth curves (ad libitum, conventional or modified restriction) and given rations containing a high or low concentration of crude protein. After the peak rate of lay they were fed ad libitum or a decreasing quantity of food in response to declining egg production. The welfare of the birds was assessed by determining the changes in indices of welfare at 36, 48 and 60 weeks of age. 2. Body weight increased rapidly in restricted birds fed ad libitum post-peak and water intake declined. 3. Post-peak food restriction was associated with a decrease in resting and increased drinking and spot-pecking activities. Birds that were food restricted during rearing spent more time foraging and spot-pecking at 36 and 48 but not 60 weeks of age. 4. Immune function increased with age but was not affected by the experimental treatments. The heterophil-lymphocyte ratio in birds fed ad libitum during rearing was numerically lower at 36 and higher at 48 and 60 weeks of age compared with restricted birds. 5. There was no effect of treatment on plasma corticosterone concentration. Creatine kinase activity was high at 60 weeks in treatments that were characterised by poor reproductive status and the activities of other enzymes reflected differences in reproductive status and mortality. 6. There was no long-term welfare or production advantage from feeding low protein rations or more generous feeding during the rearing period compared with conventional food restriction programmes.     

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。     

浅谈肉种鸡育成期的限饲管理

肉种鸡品种具有采食能力强、易沉积脂肪、生长发育快、代谢旺盛、各系统发育不一致等特点.如果在育成期任其自由采食,一方面会使饲料消耗过多,造成不必要的浪费;另一方面会使鸡的体重过大、过肥,造成运动系统、生殖系统与整体发育不协调,使其育成率降低、死淘率增加、母鸡产蛋量减少、畸形蛋增多、公鸡受精能力差.因此,为防止鸡的体重过大、过肥,减少饲料的浪费,协调性成熟与体成熟的一致性,有效控制鸡群平均体重,保持良好的体况和均匀度,必须实行限制饲养(即限饲).     

Effects of low dietary protein and different allocations of food during rearing and restricted feeding after peak rate of lay on egg production,fertility and hatchability in female broiler breeders

1. A 3x2x2 factorial experiment was conducted with boiler breeder females to determine the effects of body weight gain (three levels) and conventional or lower crude protein concentrations in the rations during rearing, and restricted or ad libitum feeding after the peak rate of lay on egg production, fertility, hatchability, mortality and food consumption. 2. Compared with ad libitum feeding, conventional food restriction resulted in a decrease in average daily food consumption of 0.6 during rearing, 0.2 during early lay and an increase of 0.4 after the peak rate of egg production. Mortality was decreased by more than half. 3. Restricted birds had higher total and settable egg production, fewer defective or damaged eggshells and higher fertility and hatchability than those fed ad libitum. The modified (more generous) rearing programme resulted in lower rates of egg production and higher rates of mortality compared with the conventional food restriction programme. 4. Low-protein rearing rations were associated with higher rates of food intake, higher mortalities and lower rates of egg production than the conventional protein rations. There were no differences in the fertility or hatchability of eggs between birds fed on the two concentrations of dietary crude protein. 5. Ad libitum feeding post-peak was associated with higher rates of mortality to 60 weeks of age. Post-peak feeding had little effect on the rate of lay or egg weight in conventionally restricted birds fed high protein rations or in birds fed ad libitum. Restricted feeding post-peak decreased the rate of lay and egg weight in birds on the modified restriction programme and in conventionally restricted birds fed on the low protein rations. There was no effect of post-peak feeding on fertility or hatchability of eggs. 6. The total numbers of saleable chicks per kg food consumed were 1.83, 1.72 and 0.52 for conventional, modified and ad libitum feeding during rearing; 1.56 and 1.15 for restricted and ad libitum feeding post-peak: there were no differences associated with protein concentrations of rations fed during rearing.     

Effect of restricted and ad libitum feeding on semen production and fertility in broiler breeder males

1. The effect of food restriction on the quality of semen production and fertility in broiler breeder males was studied.

2. Seventy‐two Ross broiler breeder males, from 20 to 54 weeks of age, were divided into 4 groups and fed as follows: group 1 = 110 g/bird/d; group 2 = 120 g/ bird/d; group 3 = 130 g/bird/d; group 4 = ad libitum.

3. Body weight, sperm quality (volume, concentration, % motility and % live cells) and fertility were measured. The birds were slaughtered at 55 weeks of age; the abdominal fat pad and testicles were weighed.

4. Groups 2 and 3 produced the highest volume of semen. The quality of semen was very similar in all the restricted groups.

5. Males fed ad libitum produced semen with the best motility and percentage of live cells. Groups 3 and 4 showed the best fertility percentage (79%) against group 1 and 2 (59 and 72% respectively).     

Effects of the age of male and female broiler breeders on sexual behaviour, fertility and hatchability of eggs

1. The effects of the age of male and female broiler breeders on fertility, hatchability and sexual behaviour were determined in two 2x2 factorial experiments. In the 1st, male and female birds 27 to 29 and 35 to 37 weeks and in the 2nd at 35 to 37 and 55 to 57 weeks of age were compared. 2. Fertility was not affected by the age of the males or females. 3. Early embryo deaths were higher and hatchability of fertile eggs was lower in eggs from females aged 27 to 29 and 55 to 57 weeks compared with eggs from birds aged 35 to 37 weeks. 4. There were no differences in male display behaviours at any age. The number of observed matings were higher in young males 27 to 29 weeks old compared with males 35 to 37 and 55 to 57 weeks of age. There were no detectable differences in the responses of the females to the males at different ages. 5. Plasma testosterone concentration in males increased from 24 to 30 weeks of age and was relatively constant from 36 to 60 weeks. Plasma oestrogen in females was high at 24 and lowest at 30 weeks of age after which it increased. 6. The results suggest that there may be little difference in the fertility of male and female broiler breeders at different ages when body weight is adequately controlled to at least 60 weeks of age.     

Effects of ad libitum feeding on performance of different strains of broiler breeders

(1) Tolerance to ad libitum feeding was compared in three genotypes of broiler breeder hens: a standard broiler breeder fed ad libitum (SA) or restricted (SR), a slow growing 'label' broiler breeder (L) and an experimental dwarf heavy broiler breeder (E). Two similar experiments were conducted in two distinct research centres. (2) Feed intake and body weight were measured every 3 weeks from hatch to 40 to 49 weeks of age. Egg production and egg abnormalities were recorded. The number of yellow follicles in ovaries was counted at the age of 32 weeks. (3) Body weight was stabilised at 2.2, 3.7 and 5.4 kg after 24 weeks of age in L, E and SA hens, respectively. Growth of the SR hens was similar to that of L up to 20 weeks and stabilised at a similar level to that of E hens after 30 weeks of age. (4) Sexual maturity was delayed by 6 weeks in restricted breeders compared to ad libitum fed hens that started to lay at 20 weeks. SA hens had low egg production and a high proportion of defective eggs, which was largely compensated for by feed restriction. However, productivity of SR hens remained lower than that of L breeders. (5) Compared to the low viability and reproductive fitness observed with SA hens, the E dwarf broiler breeder tolerated ad libitum feeding and had better egg production, fewer egg abnormalities and yellow follicles per ovary and a higher egg production. However, laying rate was still lower than that of the SR and L groups. Energy conversion (kJ/g egg) from 32 to 40 weeks of age was much higher in the SA group than in the other three groups. 6. The feasibility of feeding a dwarf broiler breeder ad libitum calls for further research on implications of specific IGF and GH-receptor expression at the level of the ovary in dw chickens.