家禽育种方法.ppt
《家禽育种方法.ppt》由会员分享,可在线阅读,更多相关《家禽育种方法.ppt(51页珍藏版)》请在三一办公上搜索。
1、家禽育种方法,家禽的选择,根据外貌与生理特征进行选择使用范围:种禽繁殖场肉用系:于5-7周龄进行选择;标准:生长迅速,体重大,羽毛丰满,无生理缺陷。蛋用系:于6-8周龄进行选择;标准:羽毛生长迅速,体重符合要求(不过大也不过小),无生理缺陷。种用育成禽:于20-22周龄进行选择;标准:体型结构、外貌特征符合品种要求,身体健康,生长发育健全。,家禽的选择,根据记录成绩进行选择性能记录蛋鸡:产蛋量,蛋重,产蛋重,蛋壳品质(蛋壳厚度和强度、蛋形、哈夫单位、蛋壳颜色、蛋壳组织、血斑与肉斑),性成熟期,产蛋率,体重,耗料、抗病力,雏鸡成活力,产蛋期成活力,受精率,孵化率等;肉鸡:上市体重,羽毛生长速度,
2、绒羽颜色,屠宰率,屠体品质,耗料,性成熟期,成年体重,蛋重,蛋壳品质,入孵蛋%,死亡率,受精率,孵化率。上述项目可根据实际情况选择记载。,家禽的选择性能测定,根据系谱资料进行选择(系谱测定)对于雏禽和育成禽,因不能断定成年后其生产性能如何,另外公禽本身不能产蛋,此时可查它们的系谱,比较不同公鸡祖先的生产性能记录以推断它们可能继承其祖先的什么性能。运用系谱测定时,血缘越近影响越大,因此一般着重比较亲代和祖代即可。根据本身成绩进行选择(个体测定)与系谱测定比较,个体测定能更准确的反映个体的性能;依据个体测定进行选择只适于遗传力较高的性状。,家禽的选择性能测定,根据全同胞和半同胞性能进行选择(同胞测
3、定)由于公禽不能产蛋,因此一般使用其全同胞和半同胞姐妹的性能对其蛋用性状进行选择;屠宰性状或屠体品质性状一般也通过同胞测定进行选择。根据后裔成绩进行选择(后裔测定)后裔测定是根据记录进行选择时准确性最高的方法;通过后裔测定的公禽一般年龄较大(至少二岁半以上),利用时间已不多,但可通过后裔测定建立优良家系。,Progeny test,The term progeny test as applied to animal breeding refers to the estimation of an individuals value as a breeder by means of the qua
4、lities or performance of its offspring.The application of the progeny test to breeding operations has brought one important fact to the attention of the poultry breeder.This is that it is not only necessary to consider the results of single pair matings but also to consider all of the offspring of a
5、 mating.,Application of progeny test to production breeding,It is doubtless true that much of the rapid progress in improvement of egg production during recent years has been due to the appreciation of the value of the progeny test as a tool by most of the leading breeders.This method not only makes
6、 it possible to predict with greater accuracy the performance of individuals but also to estimate their value as breeders,thus permitting more rapid improvement of the flock.For purposes of elimination it is very important that the poultryman have the record of a poor-producing family as well as tha
7、t of good producers.,Application of progeny test to production breeding,If the purpose is to progeny test a group of cockerels the usual procedure is to organize several breeding pens carrying females of approximately equal egg records.This may be acplished by using untested females that have just p
8、leted their first year of production.It will make possible the testing of the females as well as the males.Each pen is headed by one of the males to be tested.,Application of progeny test to production breeding,The average production of the daughters is used as a basis for parison of the ability of
9、the males to transmit egg production tendencies.By the same method it is possible to pare the females within a single pen,and since all of their daughters receive the genetic determiners for egg production on the paternal side from a single male.,Prepotency index,If the males to be pared have not be
10、en mated to females of similar egg records some pensation must be made for the variability in the dams records.An index value which might be called the“prepotency index”may be utilized in poultry breeding.Instead of using the average production of the daughters as a basis for paring the transmitting
11、 abilities of males,the average records of both their daughters and mates are considered.,Prepotency index,The first step in calculating a males prepotency index is to pute the average production of the daughters of each female mated with him.The resulting average may be considered a measure of the
12、bined transmitting tendencies of the pair of birds involved.The dams inherited tendencies for egg production are indicated by her individual egg record,but the males tendencies are unknown.,Prepotency index,The difference between the record of a female and those of her daughters should supply some c
13、lue as to her mates ability to transmit egg-production tendencies.A males breeding value is estimated as follows:A males prepotency index is then the average of the estimations obtained from the groups of daughters of his various mates.,Prepotency index,By use of the index i t is possible to pare ma
14、les mated to females of varying production,but it should be realized that the attempted corrections are sources of considerable error.It is much better,wherever possible,to pare only males whose mates are as nearly parable as possible.,Prepotency index,Difficulty in application of progeny test,One o
15、f the most serious handicaps in the application of the progeny test to production breeding is the long period of time required to make the test.If a male is used as soon as he reaches sexual maturity,or at approximately one year of age,he will be starting his fourth year before the test is pleted on
16、 his first group of daughters.Many breeders use supposedly valuable males repeatedly while the progeny test is being obtained and then discard unsuccessful blood lines and concentrate on the proved ones.This procedure involves rather extensive facilities and much lost motion.,A SHORT-CUT PROGENY TES
17、T,Any method which will provide a reasonably accurate progeny test and avoid the loss of the second years service while awaiting the results from a birds first group of offspring is of considerable value.Fortunately the influence of two of the most important factors having a bearing on the annual eg
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 家禽 育种 方法

链接地址:https://www.31ppt.com/p-6273832.html