Dairy cattle breeding.

Author(s):  
Geoff Simm ◽  
Geoff Pollott ◽  
Raphael Mrode ◽  
Ross Houston ◽  
Karen Marshall

Abstract This chapter discussed the effects of applying the different principles in animal breeding such genetic analysis, predicting breeding values, use of tools and breeding technology, selection response within breeds, and strategies for genetic improvements in dairy cattle.

1987 ◽  
Vol 44 (1) ◽  
pp. 29-38 ◽  
Author(s):  
M. E. Goddard

ABSTRACTIn the breeding of dairy cattle the selection of bulls to breed young bulls for progeny testing is a crucial process. This paper compares several policies for making this selection based on the criteria-selection response, inbreeding depression, loss of genetic variance and variability of response. A number called the ‘effective number of new bulls to breed bulls selected each year’ (NBBe) is defined which is closely related to the last three of these criteria. Past studies of the design of dairy cattle breeding programmes have assumed that selection is within a group of bulls progeny tested in the same year (policy I). However, modern sire evaluation methods allow comparison of sires tested in different years. To evaluate the effect of selecting bulls to breed bulls from all available bulls (policy II) a computer simulation program was used. Policy II results in an increase in the response to selection but a substantial decrease in NBBe. When compared at the same NBBe, policy II results in a smaller selection response than policy I. A policy which allows the best bulls to be used for more than 1 year but which limits the maximum number of years for which they can be used, results in the best compromise. If bulls are to be used for several years there is little advantage to be gained from making more matings within each year to more high-rated bulls or to older, more reliably evaluated bulls.


Author(s):  
Geoff Simm ◽  
Geoff Pollott ◽  
Raphael Mrode ◽  
Ross Houston ◽  
Karen Marshall

Abstract This chapter highlights the application of genetic principles such as strategies for genetic improvements, selection response within breeds, tools and technologies in animal breeding, genetic analysis, and predicting values in beef cattle.


2001 ◽  
Vol 2001 ◽  
pp. 219-219
Author(s):  
H. Farhangfar ◽  
P. Rowlinson ◽  
M.B. Willis

Traditionally, in most dairy cattle breeding programmes genetic evaluation of dairy sires and cows has been primarily based on 305-day lactation yield. To provide 305-day lactation yields many partial lactations have to be extended by adjustment factors resulting in overestimation or underestimation of 305-day yields which in turn leads to biased prediction of breeding values. Over the past decade there has been a considerable interest in using monthly test day records instead of 305-day lactation yield to predict breeding values of dairy cattle as early as possible and also to increase genetic gain through reducing generation interval. The main objective of present research was to estimate the genetic correlations between 305-day and monthly test day milk yields in Iranian Holstein dairy heifers.


1998 ◽  
Vol 7 (2) ◽  
pp. 207-217
Author(s):  
Jarmo Juga ◽  
Ulla Voutilainen

This paper reviews some key elements of Finnish animal breeding research contributing to the Finnish dairy cattle breeding programme and discusses the possibilities and problems in collecting data for genetic evaluation, prediction of breeding values both within and across countries, estimation of the economic value of important traits, and selection of bulls and cows. Economic values are calculated for fertility, udder health and production traits when one genetic standard deviation unit (gen. sd.) is changed in each trait independently and the financial returns from selection response in the Finnish dairy cattle breeding programme are estimated. The following components were used to calculate the economic value of mastitis treatments: 1) cost of mastitis including discarded milk and treatment costs, 2) reduction in milk price due to higher somatic cell count, 3) replacement costs and 4) lower production level of the herd due to involuntary culling of cows because of udder problems. A high somatic cell count lowers the price of milk and eventually leads to involuntary culling. For treatments for fertility disorders the following costs were included: 1) treatment costs 2) higher replacement costs and 3) decreased milk production in the herd. Days open included the following costs: 1) extra insemination, 2) reduced annual milk yield and 3) fewer calves born. Animal breeding was found to be a very cost effective investment, yielding returns of FIM 876.9 per cow from one round of selection when the gene flow was followed for over 25 years in the Finnish dairy cattle breeding programme.


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