USE OF SIB TESTING AS A SUPPLEMENT TO PROGENY TESTING TO IMPROVE THE GENETIC MERIT OF COMMERCIAL SEMEN IN DAIRY CATTLE

1987 ◽  
Vol 67 (4) ◽  
pp. 985-990 ◽  
Author(s):  
C. SMITH ◽  
J. RUANE
Keyword(s):  
Key Words ◽  
Embryo Transfer ◽  
Test Group ◽  
Progeny Testing ◽  
Genetic Trend ◽  
Commercial Use ◽  
Multiple Ovulation ◽  
Progeny Tests ◽  
Estimated Breeding Values ◽  
Current Selection

Groups of sibs, sisters to bulls being bred for progeny testing, can be produced by multiple ovulation and embryo transfer (MOET). Sib tests are complete at 3 yr of age, and progeny tests when bulls are about 5.5–6 yr of age. The merit of commercial semen could be increased by using the bulls with the highest estimated breeding values from both the sib test group and the progeny test group rather than only from the latter. With current selection rates (20%) among progeny-tested bulls for commercial use, current genetic trend (0.1 SD units per year) in bulls and with the equivalent of 3–7 full sisters per bull, the relative genetic superiority of semen from the combined groups could be from 1.10 to 1.20 times that from the progeny-tested group alone. Key words: Embryo transfer, sib testing, progeny testing, commercial semen

scholarly journals Finnish embryo transfer breeding program “ASMO” description of the goals and a summary of the results of initial selection

1996 ◽  
Vol 5 (5) ◽  
pp. 491-501 ◽  
Author(s):  
Esa A. Mäntysaari ◽  
Terhi Thuneberg-Selonen ◽  
Kaija Hyppänen ◽  
Jarmo Juga
Keyword(s):  
Embryo Transfer ◽  
Breeding Program ◽  
Protein Yield ◽  
Test Scheme ◽  
Multiple Ovulation ◽  
Genetic Base ◽  
Bull Calves ◽  
Equal Importance ◽  
Estimated Breeding Values ◽  
Efficiency Of Selection

In 1990 the organizations responsible for Finnish dairy breeding established an open nucleus multiple ovulation and embryo transfer (MOET) breeding program called ASMO. The aim was, besides to test effectiveness of MOET, to improve the protein to fat ratio in milk produced by Finnish Ayrshires but without sacrificing the progress in protein yield. The relative weights of traits were such that equal importance was assigned to protein % and protein yield. Negative weight was assigned to fat % to ensure it remained unaltered. The MOET work continued until 1994 after which the performance of selected animals has been monitored. During the five years the scheme operated, 276 cows were flushed for embryos, and 2751 embryos were recovered, of which 1810 were transferable. More than 1600 embryos were transferred to recipients, and 813 calves were born. Eighty bull calves were sold for the artificial insemination test scheme. In December 1995 the first 125 ET daughters were evaluated with the national animal model program. Their mean estimated breeding values (EBVs) were +0.13 for protein % and -0.18 for fat % compared with the genetic base of progeny tested sires born in 1986-1988, and the protein yield EBVs were 12 kg above the genetic base. Despite the efficiency of selection, the program was discontinued in 1994. Due to the difficulty of maintaining sufficient control over donor animals, there were fewer than expected embryos per flush and also too few flushes per donor.

Embryo manipulation in cattle breeding and production

1989 ◽  
Vol 48 (1) ◽  
pp. 3-30 ◽  
Author(s):  
J. A. Woolliams ◽  
I. Wilmut
Keyword(s):  
Gene Transfer ◽  
Beef Cattle ◽  
Embryo Transfer ◽  
Nuclear Transfer ◽  
Progeny Testing ◽  
Genetic Progress ◽  
Embryo Recovery ◽  
Multiple Ovulation ◽  
The Impact

ABSTRACTDevelopments, both recent and potential, in procedures for manipulating embryos are described. The procedures considered include: embryo transfer, multiple ovulation and embryo recovery, recovery of oocytes, in vitro maturation (IVM) and fertilization (IVF) of oocytes, in vitro culture of zygotes, embryo splitting and nuclear transfer, embryo storage, embryo sexing, gene transfer and embryo stem cells. The impact of these procedures on breeding strategies such as multiple ovulation and embryo transfer (MOET) nucleus breeding schemes and progeny testing are discussed for both dairy and beef cattle.For MOET nucleus schemes all these procedures have potential applications in producing maximal rates of genetic progress for a fixed rate of inbreeding. With the current effectiveness of the procedures, embryo sexing and nuclear transfer would have the most impact. The potential for increasing genetic progress through progeny testing is enhanced using multiple ovulation, embryo recovery and transfer in cows to breed bulls, but no other procedures appeared to offer major benefits. The efficiency of beef production from the dairy herd could be increased either by using IVM and IVF to produce more beef-type calves or, potentially, by cloning and embryo transfer, to produce pure beef calves. Procedures leading to the production of clone families would make an impact on the evaluation of genotypes and environments. Gene transfer may be used to modify the composition of milk including the production of pharmaceutical proteins, and to increase milk yield or the efficiency of lean meat production.It is concluded that, although much further research is required, the procedures discussed will have major implications for the structure and organization of dairy and beef cattle herds over the next decade.

Degree of connectedness among groups of centrally tested beef bulls

2004 ◽  
Vol 84 (1) ◽  
pp. 37-47 ◽  
Author(s):  
V. M. Roso ◽  
F. S. Schenkel ◽  
S. P. Miller
Keyword(s):  
Key Words ◽  
Prediction Error ◽  
Test Group ◽  
Error Variance ◽  
Harmonic Mean ◽  
Alternative Methods ◽  
Average Prediction Error ◽  
Beef Bulls ◽  
The Difference ◽  
Estimated Breeding Values

The degree of connectedness among test groups (TG) of bulls tested in central evaluation stations from 1988 to 2000 in Ontario, Canada, was evaluated using the following methods: average prediction error variance of the difference between estimated breeding values (PEVD), variance of estimated differences between test group effects (VED), connectedness rating (CR), and total number of direct genetic links between test groups (GLT). The model used in the analysis included the effects of breed and TG (fixed) and animal (random). PEVD was assumed the most adequate measure of connectedness and results from the alternative methods VED, CR, and GLT were compared against it. Models to predict the average PEVD of pairs of TG and the average PEVD of each TG with all other TG on the basis of VED, CR, and GLT were developed. Results from all measures of connectedness indicated an unfavorable trend in the degree of connectedness after 1994. The average PEVD of pairs of TG can be better predicted on the basis of the model that includes GLT. The average PEVD of each TG with all other TG can be better predicted on the basis of models that include either CR or GLT. Connectedness among TG of centrally tested beef bulls can be adequately assessed for specific pairs of TG or overall for each TG with all other TG using GLT. Key words: Accuracy, central test, genetic evaluation, harmonic mean

ESTIMATION OF GENETIC TRENDS FOR CANADIAN STATION-TESTED BEEF BULLS

1988 ◽  
Vol 68 (1) ◽  
pp. 49-56 ◽  
Author(s):  
E. P. de ROSE ◽  
J. W. WILTON
Keyword(s):  
Key Words ◽  
Average Daily Gain ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Testing Program ◽  
Scrotal Circumference ◽  
Beef Bulls ◽  
Estimated Breeding Values ◽  
Daily Gain ◽  
Genetic Trends

Data collected from Canadian central test stations were used to obtain estimates of genetic progress for test station average daily gain (ADG-T), height at hooks (HH), ultrasonically measured backfat thickness midway between the 11th and 12th ribs (FAT) and scrotal circumference (SC). Where possible, records for preweaning average daily gain (ADG-W) from the Federal-Provincial Herd Record of Performance program were obtained for tested bulls. Estimated breeding values were regressed on year of birth to obtain estimates of genetic trend for each trait, for the six principal breeds enrolled in the testing program: Aberdeen Angus (AA), Charolais (CH), Hereford (HE), Limousin (LM), Shorthorn (SH) and Simmental (SM). Estimated trends were generally significant with the exception of those for the LM breed, and the trait of SC. For FAT, trends were generally positive for the exotic breeds, and negative for the British breeds. Significant positive trends were observed for HH, ADG-W and ADG-T for most breeds. Examples of estimated genetic trends, for the HE breed, were 0.0022 kg d−1 yr−1, 0.0023 kg d−1 yr−1, 0.090 cm yr−1 (NS), − 0.029 mm yr−1, and 0.009 cm yr−1 (NS), respectively, for ADG-W, ADG-T, HH, FAT and SC (NS = not significant). Most estimated trends were low, in the order of 0.1 to 0.5% of population mean per year. Key words: Genetic trend, central test stations, beef bulls

Increased rates of genetic change in dairy cattle by embryo transfer and splitting

1983 ◽  
Vol 36 (3) ◽  
pp. 341-353 ◽  
Author(s):  
F. W. Nicholas ◽  
C. Smith
Keyword(s):  
Dairy Cattle ◽  
Embryo Transfer ◽  
Genetic Improvement ◽  
Genetic Change ◽  
Progeny Testing ◽  
Generation Interval ◽  
Advantages And Disadvantages ◽  
Multiple Ovulation ◽  
Inbreeding Rate ◽  
Old Females

ABSTRACTPossibilities for increased rates of genetic change in dairy cattle through embryo transfer and embryo splitting are examined, using the multiple ovulation and embryo transfer systems previously proposed. These involve embryo transfer from 1-year-old females (juvenile scheme, generation interval 1·8 years) and from females after 1 lactation (adult scheme, generation interval 3·7 years), with use of males at similar ages. Though selection is less accurate than in conventional progeny testing, the annual rate of genetic improvement can be increased, and even doubled. If the number of transfers is restricted andm the inbreeding rate is limiting, the adult scheme for both sexes is preferred. A scheme with 1 024 transfers per year and 512 females milk-recorded per year will sustain a rate of genetic improvement some 30% above that possible by a conventional national progeny-testing programme. Because of the relatively small number of animals involved, it is argued that greater control over recording, breeding and selection should be possible, leading to a larger proportion of the possible genetic gains being realized in practice. Other advantages, and disadvantages of these systems, and their integration in dairy cattle improvement are discussed.

Breeding programs in dairy cattle - current and future considerations

1988 ◽  
Vol 12 ◽  
pp. 129-152
Author(s):  
A. E. Freeman
Keyword(s):  
Dairy Cattle ◽  
New Technologies ◽  
Transgenic Animals ◽  
Efficient Production ◽  
Progeny Testing ◽  
Linear Unbiased Prediction ◽  
Multiple Ovulation ◽  
Pedigree Selection ◽  
Best Linear Unbiased ◽  
Reducing Costs

Methods of evaluating dairy cattle using mixed models with Best Linear Unbiased Prediction properties have progressed from the sire model to the animal model. Definitions of effects in models need refinement, particularly for contemporary groups. Pedigree selection and progeny testing is the standard for producing sires used in artificial insemination, but multiple ovulation and embryo transfer schemes are being tried. Efficient production is necessary under conditions of surplus. Efficiency can be achieved by higher production per cow and reducing costs by improved reproduction, increased herd life, reduced health costs, and reduced dystocia. Preferential treatment is a major problem. New biotechnological developments such as bovine somatotropin, mitochondrial genetics, sexing semen, embryo transfers, cloning, transgenic animals, and markers are considered as potential new technologies that may be useful for dairy cattle improvement.

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