What the Breeder Sells and the Producer Buys: Breeding Value

A breeding value is the value of an individual as a parent. This is precisely what breeding stock herds sell. It is the value of the progeny from their breeding stock in the herd of the buyer that is the issue. As specification of product becomes more important in the beef industry, breeders can be merchandizing breeding value. Beef breeders are selling a product that must transmit a sample half of its germ plasm to progeny before the result is realized. Commercial producers sell pounds, not breeding value, but they need to buy breeding value as well as combine breeds in logical combinations to obtain the crossbred advantages especially for the reproductive complex. Thus, both the commercial and breeding stock producer can benefit from understanding the concept of breeding value. The purpose of this paper is to define and describe the breeding value concept and to examine ways to use the concept in practice

Inheritance of coat coloration and spotting patterns of cattle: A review

An understanding of the inheritance of coat coloration and white markings in cattle is useful for several reasons. The first is its potential usefulness in the teaching of Mendelian principles to agricultural students. A second would be its usefulness in the development of composite breeds of cattle in which a uniform coat coloration may be desirable. A third is that there may be interest in determining which breeds could be used in crossbreeding programs to produce uniformly colored terminal cross calves. Also, Lauvergne (1966) discussed a review article by J. D. Findlay where it is concluded that pigmentation can affect the productive performance of animals under certain conditions such as in the tropics where animals with darkly pigmented skins and light-colored coats seem best adapted. Finally, animals without pigmented eyelids seem more susceptible to cancer eye” (Anderson et al., 1957). The inheritance of coat coloration and white spotting in cattle has been studied by many scientists since the beginning o f this century. Ibsen (1933) provided a summary of the segregating loci that had been reported and postulated others. Lauvergne (1966) produced an excellent summary of the existing information, but his summary is not readily useful in the United States, primarily because it is published in the French language. This publication will draw upon the conclusions of Lauvergne and modify and expand them

A Project to Develop Genetic Specification for the Beef Industry

A new beef breeding project will be conducted at the Rhodes and McNay farms of ISU. The project will use the field data of the American Angus Association along with the research resources (cattle) of the farms to study questions that will enhance the genetic investigations using the field data. It will build on the expertise developed at ISU with ultrasound to measure body composition in the live animal and in the carcass. Two selection lines, using registered Angus obtained as heifers and through ET, of 200 females each will be selected for increased intramuscular fat (Q line) and for increased retail product (R line). The estimation of the genetic correlation between quality and amount of product can best be accomplished through the study of one generation of selection using measures of body composition derived from ultrasound. A progeny test herd will be maintained to evaluate all sires used through progeny carcass testing and to further research with ultrasound. The project will study efficiency of body maintenance. Results will be shared through the Beef Improvement Federation to benefit all producers in the development of sound programs to profitably produce specified beef products

The sperm factor: paternal impact beyond genes

The fact that sperm carry more than the paternal DNA has only been discovered just over a decade ago. With this discovery, the idea that the paternal condition may have direct implications for the fitness of the offspring had to be revisited. While this idea is still highly debated, empirical evidence for paternal effects is accumulating. Male condition not only affects male fertility but also offspring early development and performance later in life. Several factors have been identified as possible carriers of non-genetic information, but we still know little about their origin and function and even less about their causation. I consider four possible non-mutually exclusive adaptive and non-adaptive explanations for the existence of paternal effects in an evolutionary context. In addition, I provide a brief overview of the main non-genetic components found in sperm including DNA methylation, chromatin modifications, RNAs and proteins. I discuss their putative functions and present currently available examples for their role in transferring non-genetic information from the father to the offspring. Finally, I identify some of the most important open questions and present possible future research avenues

GENETIC PREDICTION FOR BEEF IN UNITED STATES

Beef performance programs have come a long way since their start after World War II as a means of within-herd improvement. Now performance programs can be used to rank young animals on all the available information across all the herds of a breed. Opportunity exists to design and conduct performance programs that can be used to promote the breed, enhance management decision making, and make real genetic change in the breed

Estimation of Non-Additive Genetic Variances in Three Synthetic Lines of Beef Cattle Using an Animal Model

Dominance and additive x additive genetic variances were estimated for birth and weaning traits of calves from thee synthetic lines of beef cattle differing in mature size. Data consisted of 3,992 and 2,877 records from lines of small-, medium-, and large-framed calves in each of two research herds located at Rhodes and McNay, IA, respectively. Variance components were estimated separately by herd and line for birth weight (BWT), birth hip height (BH), 205-d weight (WW), and 205-d hip height (WH) by derivative-free REML with an animal model. Model 1 included fixed effects of year, sex, and age of dam. Random effects were additive direct (a) and additive maternal (m) genetic with covariance (a,m), maternal permanent environmental, and residual. Model 2 also included dominance (d) and model 3 included dominance plus additive x additive (a:a) effects. In general, only slight changes occurred in other variance components estimates when day was included in Model 2. However, large estimates of additive x additive genetic variances obtained with Model 3 for 4 out of 24 analyses were associated with reductions in estimates of direct additive variances. Direct (maternal) heritability estimates averaged across herd-line combinations with Model 2 were .53(.11), .42(.04), .27(.12), and .35(.04) for BWT, BH, WW, WH, respectively. Corresponding covariance (a,m) estimates as fractions of phenotypic variance (σp2) were .00, .01, .01, and .06, respectively. For maternal permanent environmental effects in Model 2, average estimates of variances as fractions of σp2 across herd-line combinations were .03, .00, .05, and .02, for BW, BH, WW, and WH, respectively. Dominance effects explained, on average, 18, 26, 28, and 11% of total variance for BWT, BH, WW, and WH, respectively. Most of the estimates for additive x additive variances were negligible, except for one data set for BWT, two for BH, and one for WH, where the relative estimates of this component were high (.21 to .45). These results suggest that most of the non-additive genetic variance in the traits studied is accounted for by dominance genetic effects

Oklahoma Agricultural Experiment Station, Bulletin no. 262, November 1942: Experiments in creep-feeding beef calves

The Oklahoma Agricultural Experiment Station periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

Oklahoma Agricultural Experiment Station, Bulletin no. 235, May 1938: Creep feeding and finishing beef calves

The Oklahoma Agricultural Experiment Station periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311