岭南黄鸡快,慢羽品系的生产性能

岭南黄鸡快、慢羽新品系雏鸡在出壳后２４小时内利用羽速自别雌雄的准确率达９４．１％，快羽Ｃ系和慢羽Ｄ系０，４，８，１２周龄的平均体重及１２周龄的料肉比的差异均不显著（Ｐ＞０．０５）；１２周龄存活率快羽Ｃ系为９５．０３％，明显高于慢羽Ｄ系的８８．７６％。     

新杨绿壳蛋鸡和白来航鸡快慢羽品系产蛋性能比较

本试验就新杨绿壳蛋鸡、白来航鸡快羽和慢羽品系的部分产蛋性能进行比较研究。结果表明:白来航鸡快羽品系的25~45周龄总产蛋数、49周龄蛋重、母鸡体重和蛋壳颜色均显著高于新杨绿壳蛋鸡(P0.01),且优于白来航慢羽品系的同类性状;25~45周龄总产蛋数与49周龄蛋重、母鸡体重和蛋壳颜色呈极显著正相关(P0.01);49周龄蛋重与体重和蛋壳颜色呈极显著正相关(P0.01);49周龄母鸡体重和蛋壳颜色呈极显著正相关(P0.01)。总体来看,白来航鸡快羽和慢羽品系的性状变异系数小于新杨绿壳蛋鸡,其变异系数均小于10%。新杨绿壳蛋鸡的性状变异系数稳定性差,平均变异系数超过10%,仅蛋重和蛋壳颜色的变异系数略低于10%,这说明在规模化生产时,新杨绿壳蛋鸡的选育还有待加强,从而使产蛋性状更加稳定。     

快慢羽基因对坝上长尾鸡早期体重与羽速生长的影响

为研究坝上长尾鸡快慢羽基因对早期体重与羽速生长的影响,对0~10周龄坝上长尾鸡体重与羽速生长进行了测定分析。结果表明,坝上长尾鸡快羽与慢羽0~10周龄体重差异不显著(P0.05),快羽鸡主翼羽和副翼羽长度在2周龄时显著大于慢羽(P0.05),随着周龄增加差异逐渐减小,育雏期末差异不显著(P0.05),8周龄慢羽鸡主翼羽和副翼羽长度显著大于快羽(P0.05)。快羽鸡1~3周主翼羽与副翼羽差异较小,随着鸡的生长差异增大,慢羽鸡1~4周主翼羽与副翼羽差异较大,随着鸡的生长差异减小,育雏期结束时,主翼羽发育优势体现出来,因此,1~4周翼羽的生长可以作为坝上长尾鸡快慢羽鉴定的辅助方法。快羽鸡在1周龄开始长出尾羽,慢羽鸡在3周龄以后开始长出尾羽,可以根据尾羽的生长情况对坝上长尾鸡进行快慢羽鉴别,鉴定时间最好控制在1~6周。     

快慢羽性状对罗曼蛋鸡母雏生长的影响

为充分体现快慢羽性状对生长的作用,消除品种或品系不同对试验结果的影响,本试验以1日龄罗曼蛋鸡商品代快羽母雏和慢羽母雏作为试验动物,进行同一配套系鸡种商品代母雏鸡中快慢羽性状对生长影响的试验。结果显示:罗曼蛋鸡商品代的快羽母雏鸡要比慢羽母雏鸡生长快,饲养至42日龄时,快羽母雏体重极显著高于慢羽母雏(P<0.01)。     

碱性磷酸酶同工酶与产蛋性能的关系

本文利用聚丙烯酰胺垂直板高压电泳分离了18周龄115只岩谷蛋鸡的血清碱性磷酸酶同工酶.其中快型35只,慢型80只。并就快慢两型的体重、血液中某些生化指标和产蛋性能进行比较。结果表明:快型同工酶的鸡,8周龄体重、血清碱性磷酸酶活力、开产蛋重、开产日龄、300日龄体重、300日龄蛋重,极显著的大于慢型鸡,而300日龄和504日龄产蛋数极显著的低于慢型鸡。     

四川山地乌骨鸡黄羽系快、慢羽群体羽毛和体重的早期发育分析及基因型鉴定

为了探明四川山地乌骨鸡黄羽系快、慢羽群体羽毛与体重早期发育的关系,试验测定了1～35日龄四川山地乌骨鸡黄羽系的主翼羽、覆主翼羽、尾羽羽毛长度及其体重并鉴定快、慢羽基因型。结果显示:四川山地乌骨鸡黄羽系在21日龄之前快羽鸡主翼羽长度显著或极显著长于慢羽鸡(P0.05或P0.01);整个试验周期中,3日龄快羽鸡的覆主翼羽显著长于慢羽鸡(P0.05),而在14和21日龄等长慢羽鸡的覆主翼羽显著长于快羽鸡和典型慢羽鸡(P0.05);快、慢羽鸡14日龄开始出现尾羽,在14、21和28日龄,快羽鸡的尾羽显著长于慢羽鸡(P0.05),35日龄等长型慢羽鸡的尾羽显著长于典型慢羽鸡(P0.05);5日龄等长慢羽鸡体重显著高于快羽鸡(P0.05),14日龄典型慢羽鸡的体重显著大于快羽鸡(P0.05),21日龄之后典型慢羽鸡体重显著高于等长慢羽鸡和快羽鸡(P0.05);表型鉴定为慢羽的群体中有5只基因型鉴定为快羽,表型鉴定为快羽的群体基因型鉴定均为快羽,基因型鉴定结果与表型鉴定吻合率达91.7%。研究表明,通过主翼羽与覆主翼羽的相对长度及基因型鉴定,可在1日龄有效判断四川山地乌骨鸡黄羽系快、慢羽个体,结果为建立四川山地乌骨鸡黄羽系快、慢羽亚系奠定了基础。     

固始鸡快慢羽纯系的选育及自别雌雄效果研究

对固始鸡自然群研究得知，快羽占8．60％，慢羽占91．40％，说明固始鸡的原始种群主要以慢羽为主。其羽型分布结果为：快羽中R1型占68％，R2型占32％；慢羽中，倒长型占58．8％，等长型占16.5％，未长型占24．7％，未出现微长型。依据鸡的快慢羽显隐性关系以及伴性遗传的原理，通过个体选择、测交和纯繁扩群等方法建立了固始鸡快、慢羽纯系。将建立起来的固始鸡快、慢羽纯系进行纯繁，其后代快羽及慢羽比例分别达到了99.5%和99．7％以上。经两系自别配套知，其后代雏鸡羽速自别雌雄的准确率达到了99%以上。     

庄河大骨鸡快慢羽品系体尺及蛋品质的测定与分析

为探究庄河大骨鸡快慢羽种鸡群的种质特性,试验测定庄河大骨鸡快慢羽种群体重、体尺及蛋品质等指标,并进行分析。结果表明:庄河大骨鸡慢羽种鸡6 w时,公、母鸡平均体重为705.5 g,18 w公鸡体重显著高于母鸡体重(P0.05);快羽种鸡6 w时,公、母鸡平均体重为665.5 g,18 w公鸡体重显著高于母鸡体重(P0.05)。18 w时,快慢羽种鸡群的体尺指标差异明显(P0.05)。慢羽种鸡群蛋白重显著高于快羽种鸡群(P0.05),其余蛋品质指标均差异不显著(P0.05)。研究表明,庄河大骨鸡早期生长速度较快,慢羽品系优于快羽品系;慢羽品系体尺上优于快羽品系。     

贵州黄鸡慢羽系生长曲线拟合研究

试验旨在揭示贵州黄鸡慢羽系生长发育规律。选择100只贵州黄鸡慢羽系（公母鸡各50只），于0、2、4、6、8、10、12、14周龄末称重，分别采用Bertalanffy、Logistic、Gompertz 3种非线性生长曲线模型对贵州黄鸡慢羽系0~14周龄体重变化进行拟合分析。结果表明：3种模型均能很好地拟合其生长曲线，拟合度均在0.99以上，其中Logistic模型在贵州黄鸡慢羽系公鸡、母鸡生长曲线中拟合最好，拟合结果最接近实测体重情况，其公鸡拐点体重为1 550.81 g，拐点周龄为10.42，母鸡拐点体重为976.67 g，拐点周龄为9.14。试验结果初步揭示了贵州黄鸡慢羽系的生长发育规律和各阶段的生长特征，为贵州黄鸡慢羽系选育生产和产业化发展提供了科学依据。     

快慢羽品系贵妃鸡体尺性状及屠宰性能的比较分析

对20周龄的6只快羽贵妃鸡与6只慢羽贵妃鸡的体尺性状与屠宰性能进行比较分析.结果表明,两品系间的体尺性状与屠宰性能均为慢羽鸡大于快羽鸡,且髋宽、半净膛率两品系间差异显著(P<0.05).两品系间的内脏器官的体积大小和骨架结构大小存在一定的规律性,骨架指数与睾丸重慢羽鸡均大于快羽鸡,器官指数则是慢羽鸡小于快羽鸡.     

Absence of influence on immune competence by the sex-linked gene (K) determining slow feathering in white leghorn chickens

Males of white leghorn strain crosses heterozygous (Kk) for the sex-linked feathering locus genes were mated to rapid-feathering (k-) females to produce rapid- and slow-feathering chicks of both sexes. K did not influence humoral-mediated immunity against challenge with sheep erythrocytes, killed Brucella abortus, or killed infectious bursal disease virus. Chicks challenged at 3 weeks of age had higher primary responses and higher titers of 2-mercaptoethanol-resistant antibody (IgG) than those challenged at 1 week of age. K had no influence on levels of cell-mediated immunity based on responses in in vitro phytohemagglutinin tests of donors 2 to 126 days of age, on responses in in vitro one-way mixed-lymphocyte cultures, and on rejection rates of skin grafts on young chicks. Feathering type did not influence viremia or antibody to avian leukosis virus; the level of lymphoid leukosis tumors was higher in rapid-feathering females than in slow-feathering females at 28 weeks of age (53% vs. 72%; P less than or equal to 0.10). We conclude that K does not influence general immune competence. The possibility that it may influence specific immunity to ALV under conditions not met in this study, because of an endogenous virus recently associated with the K locus, is discussed.     

北京油鸡快慢羽母鸡鉴定以及羽毛发育、生长和产蛋性能的对比分析

试验旨在为北京油鸡品系选育、配套利用和科学养殖提供基础数据。选用北京油鸡纯系母雏534只,开展快慢羽群体的鉴定,并对比快慢羽母鸡羽毛发育、生长和繁殖性能的差异。北京油鸡保种群出雏时按照主翼羽与覆主翼羽的相对长度表型特征鉴别,将其分为快慢羽亚群,其中快羽包括K1（主翼羽长于覆主翼羽5 mm以上）和K2（主翼羽长于覆主翼羽2~5 mm）,慢羽包括M1（主翼羽与覆主翼羽等长或主翼羽长于覆主翼羽2 mm以内）、M2（主翼羽短于覆主翼羽）和M3（主翼羽未长出）。6周龄时通过PCR方法进行再次鉴定快慢羽。7 d内每隔1 d测量1次主翼羽与覆主翼羽羽长;7~42 d每隔1周测量1次;1~8周每周测定体重,9~18周每隔1周测定体重;产蛋期根据个体产蛋记录统计群体开产日龄、个体产蛋数以及连产相关性状等产蛋性能。结果表明,北京油鸡初生雏鸡快慢羽表型鉴定结果与通过PCR方法鉴定的结果一致,快羽鸡占总数的25%,慢羽鸡占75%,慢羽鸡又以M2为主,有少量M1和M3。21日龄以内快羽鸡的主翼羽羽长显著高于慢羽鸡（P<0.05）;28日龄时,M1和M2型慢羽鸡的主翼羽长度与快羽鸡差异不显著（P>0.05）,但是M3仍显著短于快羽鸡（P<0.05）。与慢羽鸡相比,快羽鸡70日龄后体重显著增加（P<0.05）,且开产日龄显著提前（P<0.05）,但是43周产蛋数较低（P<0.05）;快羽鸡除蛋形指数显著高于慢羽鸡外（P<0.05）,其他蛋品质指标均无显著差异。综上,快慢羽北京油鸡在生长和产蛋性能上有一定差异,在选育方向和生产管理中应有所差异化,包括加强慢羽品系早熟性即开产日龄的选育和调整快羽品系育成期饲料能蛋水平等。     

北京油鸡快慢羽公鸡鉴定及羽毛发育、生长和繁殖性能的对比分析

试验通过开展快慢羽群体的鉴定,并对比其在羽毛发育、生长和繁殖性能方面的差异,旨在为北京油鸡种鸡选育和科学养殖提供数据支持。选用北京油鸡纯系公鸡,出雏时,按照主翼羽与覆主翼羽的羽长差值将其分为快慢羽亚群,其中快羽包括K1（主翼羽长于覆主翼羽>5 mm）和K2（主翼羽长于覆主翼羽2~5 mm）,慢羽包括M1（主翼羽与覆主翼羽等长或主翼羽长于覆主翼羽<2 mm）和M2（主翼羽短于覆主翼羽）和M3（主翼羽未长出）。1~7日龄每隔1 d测量1次主翼羽与覆主翼羽羽长,7~42日龄每隔1周测量1次;1~8周龄每周测量体重,9~18周龄每隔1周测定体重;10周龄时,观测公鸡全身羽毛发育情况;47周龄时,测定公鸡常规精液品质性状、精子动力学参数、受精率及孵化率。结果显示,快羽公鸡占北京油鸡公鸡总数的11.60%,慢羽占88.40%,慢羽又以M2型为主,有少量M1型和M3型。育雏育成期（1~18周）北京油鸡快慢羽公鸡各周龄体重均无显著差异（P>0.05）。在育雏育成期,慢羽公鸡主翼羽和覆主翼羽生长均慢于快羽公鸡。其10周龄时,背部和腿部羽毛生长完全的鸡的比例仅为44%,且不同类型的慢羽公鸡的比例也不一,其中等长型或微长型慢羽最高,超过90%,未长出型慢羽最低,仅为17%左右。47周龄时快羽鸡和慢羽鸡的常规精液品质无差异,但是快羽公鸡精子直线性显著高于慢羽鸡（P<0.05）,直线速率高于慢羽公鸡（P=0.06）,快羽北京油鸡公鸡受精率显著高于慢羽公鸡（P<0.05）,且入孵蛋孵化率和受精蛋孵化率有高于慢羽公鸡的趋势,但差异不显著（P>0.05）。本研究结果表明,快慢羽北京油鸡公鸡的羽毛生长和繁殖性能有一定差异,需要加强慢羽公鸡羽毛发育缓慢原因和鉴定方法的研究,也需加强慢羽公鸡精液品质选育。     

清远麻鸡快慢羽系羽速与生产性能的研究

试验选取清远麻鸡快慢羽群体共200只,通过对初生羽毛长度、体重、鸡冠高度和羽毛成熟性等指标的测定,并对初生羽毛长度和羽毛成熟性进行相关性分析,探讨清远麻鸡快慢羽系各阶段生产性能的差异,解析初生羽毛长度与早熟性状之间的关系。结果表明:(1)1日龄快羽R2型的主翼羽长度和平均羽毛长度均极显著长于慢羽倒长型(L2)(P<0.01),但其主翼羽和覆主翼羽长度差值极显著短于慢羽倒长型(L2)(P<0.01);(2)42日龄时,慢羽倒长型(L2)公鸡体重极显著大于快羽R2型(P<0.01);110日龄时,快羽R2型母鸡的冠高显著高于慢羽母鸡(P<0.05),同时,快羽R2型母鸡羽毛成熟性也极显著优于慢羽倒长型(L2)母鸡(P<0.01);(3)快羽R2型鸡羽毛成熟性与初生翼羽长度呈中度正相关(r=0.264~0.322),分别达到显著水平(P<0.05)或极显著(P<0.01)。研究结果提示,清远麻鸡快慢羽系中最常见的快羽R2型和慢羽倒长型(L2)的各阶段的生产性能具有一定的差异,快羽R2型的初生羽毛长度可对羽毛成熟性实施间接选育。     

Effect of pre-incubation storage conditions on hatchability,chick weight at hatch and hatching time in broiler breeders

1. Eggs were stored for two different times at varying temperatures. The effects on hatchability, chick weight at hatch and hatching time were examined in two broiler breeder lines from 33 to 58 weeks of age. 2. Short storage (1 to 3 d). Storage at 20 degrees C compared with 16.5 degrees C reduced hatchability of all eggs set. No effect was observed on hatchability of fertile eggs, hatching time or chick weight. 3. Long storage (9 to 11 d). Storage at 16.5 degrees C compared with 10 degrees C decreased both hatchability of fertile eggs and chick weight at hatch. Incidence of early embryonic death increased and incubation time decreased at 16.5 degrees C compared with 10 degrees C. 4. Chicks from morning eggs were heavier than those from afternoon eggs irrespective of storage conditions. 5. Hatchability (all eggs set and fertile eggs) and chick weight varied with hen age irrespective of storage conditions. During long storage, hatching time varied with hen age independently of breeder line, storage temperature or egg laying time. 6. Hatchability (all eggs set and fertile eggs) was higher in line A than in line B. Line B eggs hatched later and produced heavier chicks than line A eggs irrespective of storage time.     

Selection for postweaning gain in rats: II. Correlated response in reproductive performance

Reproductive performance was evaluated on lines of rats selected 34 generations for up (U) and down (D) 3- to 9-wk weight gain and from a control (C). Direct response to 3- to 9-wk weight gain was 16% in U and -8% in D lines. Inbreeding was similar among lines. Both selection lines were poorer in percentage of fertile pairs than the C line, especially so in D (P less than .10). The lines differed (P less than .05) in litter size born with means of 11.4, 10.4 and 9.6 for U, C and D, respectively. The significant positive correlated response in litter size corresponded to that expected from intraline association with female body weight. Selection for increased postweaning gain resulted in 5% earlier age but little change in weight at vaginal opening. The D line was similar to C in age, but 7% lighter in weight at vaginal opening. The U line was significantly higher (14, 12 and 69%) for ovulation rate, number of fetuses and post-implantation losses, but not for pre-implantation losses. The D females were similar to C females in all components of litter size. Males of all lines were similar in age at first mating, but U males were 22% heavier than C males in weight at first mating. A positive correlated response in weight of testes at 91 d of age disappeared when adjusted for intraline association with body weight.     

Effects of feeding pattern and dietary regimen on growth and adipose tissue cellularity in polygenic obese mice

The effect of varying feed intake and feeding pattern during the early postweaning period on growth, body composition and adipose tissue cellularity was studied in polygenic obese and control normal mice. Male mice were assigned to the following dietary treatments at 4.5 wk of age: stock diet fed ad libitum(AL), four palatable foods cafeteria-fed(CF), stock diet fed every 2 h by automatic feeders adjusted for maximum intake(MI), fed same procedure as MI but restricted to produce 70% of the gain of mice fed ad libitum(RE), and stock diet fed one meal/d the same amount fed RE mice(PM). Mice were killed after 5 wk on treatment. Cafeteria-fed control mice were heavier (P less than .05) than RE control mice, but they were not different (P greater than .05) from AL, MI and PM control mice, while CF obese mice were heavier and RE obese mice were smaller than AL, MI and PM obese mice (P less than .05). Cafeteria-fed mice were fatter than mice from all other treatments in both the obese and control lines. Maximum intake, PM and RE mice were fatter than AL mice but this effect was only significant in the obese line. Alterations in feeding pattern can affect body composition even though body weight may not show a correlated response. Cafeteria-fed obese mice had larger fat pads and more small (less than 40 micron) and large (greater than 110 micron) adipocytes than other obese mice. Results indicate that the difference in the development of obesity on cafeteria diet was due primarily to genetic effects while the increase in percentage fat after restriction on MI, PM and RE treatments was due mainly to the acute change of feeding pattern.     

Effects of divergent selection for incidence of tibial dyschondroplasia (TD) on purebred and crossbred performance. 2. Processing yield

1. An experiment was conducted to determine the effect of selection for high (H) or low (L) incidence of tibial dyschondroplasia for 7 generations on processing performance of broilers. 2. Birds were obtained from diallel matings of the H and L lines (HH, HL, LH, and LL) and a randombred control (CC) line. Birds were reared to 7 weeks of age under standard management conditions. All birds were processed at 7 weeks of age. Body weight at 7 weeks, carcase weight, and carcase part weights were recorded on each bird. 3. An interaction between sire line and dam line was caused by lighter body and carcase weight at 7 weeks of age in HH birds than from the birds of the other crosses. 4. Birds by L line dams had heavier drumstick weights. The influences of sire line and dam line on weight of total breast muscle were not significant. Thigh weights and Pectoralis minor weights were lighter in HH line birds than those other matings. 5. Heterosis for body weight and for weights of carcases, drumstick and thigh was negative. Total breast muscle weight and P. major weight did not show significant heterosis. 6. It was concluded that selecting against TD does not reduce processing yield of broilers.