Life Sciences Commons^™

Genetic Parameters For Gestatiob Length, Birth Date And Time To First Observed Estrus Ib Beef Cattle, Sara Melin Azzam, M. K. Nielsen

3rd World Congress on Genetics Applied to Livestock Production

Genetic and environmental variability in gestation length (GL), birth date (BD), and time from first day of breeding season to first observed estrus (FE) were analyzed ·using twelve years of breeding and calving records on cows, sired by Simmental, Maine-Anjou, Limousin and Gelbvieh bulls. All cows were artificially inseminated. Statistical analyses were performed separately on first, second and last parity records. Paternal half-sib estimates of heritability for GL as a trait of the calf were between .36 and .45 while the estimates for BD were between .09 and .24. The estimates of heritability for FE, treated as a trait of …

Preliminary Results On Fertility, Prolificacy, Lamb Production, And Carcass Traits Of Romanov Sheep In Canada, Mohamed Hamed Fahmy

3rd World Congress on Genetics Applied to Livestock Production

Performance of 14 ewes imported from France and their progeny born in Canada over a period of five years are reported. Least-squares means for fertility were 100% for ewes mated in the fall and winter and 42% for those mated in the summer (May - June). Litter size at birth (2.86 ± .15) and at weaning (2.10 ± .15) were significantly affected by season of mating and parity. The most prolific matings were those of the fall (3.18) and of ewes in their 5th parity (3.54). On the average .52 (18.2%) lambs died at birth and a further .25 (8.7%) …

Optimization Of A Selection Scheme For Milk Composition And Yield In Milking Ewes : Example Of The Lacaune Breed, F. Barillet, J. M. Elsen, M. Roussely

3rd World Congress on Genetics Applied to Livestock Production

Management of the genetic improvement of milking ewes depends: on the obvious fact that they are both dairy animals and sheep. This paper deals with the Lacaune breed situation in France. It paints out the way to build the selection scheme,on two particular aspects:the need to rationalize and simplify milk recording both for milk composition and milk yield, and the concurrent use of AI and natural mating, within the scope of a pyramidal management of the population. We sum up the main results of studies on these different aspects in this paper. In the course of the last twenty years,phenotypic …

Performance Recording For Merino Sheep In Australia (Woolplan), R. P. Lewer, R. W. Ponzoni, P. D. Morgan, D. S. Vanrenen

3rd World Congress on Genetics Applied to Livestock Production

Merinos are the predominant sheep breed in Australia, accounting-for about 76% of a total of 150m. Approximately 197,000 Merino rams are sold annually, of which 157,000 are horned and 40,000 are polled.

The Australian Merino is above all a producer of premium quality white wool. The major determinant of wool income is weight, but the price per kilogram is influenced mainly by fibre diameter.

Recording in Merino stud flocks is minimal. Sires are sometimes identified but dam identities are not routinely recorded. Neither are required for registration purposes. Subjective grading of breeding stock is still the main selection criterion, but …

Male Heterosis Effect On Lamb Production Traits Of The Ewe, T. S. Ch'ang, R. Evans

3rd World Congress on Genetics Applied to Livestock Production

In a CSIRO Sheep Heterosis Experiment, 387 F₁ ewes were mated to either purebred, F₁ or F₂ rams for studying the effect of male heterosis on several lamb production traits and to investigate pro rata retention of male heterosis based on the dominance hypothesis. Evidence was found to demonstrate the occurrence of a moderate effect due to the F₁ rams (versus the purebreds) and the dominance hypothesis appeared adequate to account for the pro rata retention i.e. at 50%, of heterosis in the F₂ rams.

Milk And Beef Production In Tropical Environments, V. K. Taneja, P. N. Bhat

3rd World Congress on Genetics Applied to Livestock Production

Cattle breeds native to tropics are late maturing and poor producers of milk and beef, but have the ability to survive under harsh tropical environments. In spite of large, genetic variability for milk yield. selection for productive traits would not be effective in bridging the gap between requirements of human food and its availability. Other methods to achieve these goals have been suggested. Breed comparison studies are needed to identify special genes for fast growth, efficient breeding and resistance to diseases and drought capacity, alternatives like replacement of native with improved European breeds and gene transfer through crossbreeding have been …

Genetic Variability And Sire X Mating System Interaction For Milk Yield In Holstein-Sahiwal Crosses, V. P. Rao, V. K. Taneja

3rd World Congress on Genetics Applied to Livestock Production

The average first lactation milk yield of crossbreds in northern region was higher than that in southern region with heritability estimates being 0.16±0.06 and 0.04 ± 0.04. The heritability estimates according to production level were 0.28 ± 0.14, -0.02 ± 0.04 and 0.36 ± 0.15 for low, medium and high level herds in northern and -0.05 ± 0.01 and 0.03 ± 0.12 for low and high level herds in southern region,suggesting more genetic viability in relation to total variance in high level herds. The reasons for low estimates in medium level herds have been discussed. The sire x genetic group …

Impact Of Industry Structure, Intensity Of Production And Resource Constraints On Research Breeding Objectives, J. W. Wilton

3rd World Congress on Genetics Applied to Livestock Production

The importance of the structure of the beef industry with respect to crossbreeding programs and division into cow-calf and feedlot segments; intensity of production with respect to market standards, feeds and labour; and resource constraints with respect to feed, labour, land and capital; are discussed and quantified where possible. The use of discounted gene flow provides estimates of relative expression rates which differ with crossbreeding programs and relative sizes of populations of purebred and commercial cattle. The importance of feedback from feedlot to cow-calf to purebred operation is emphasized, for both discounted expression rates and modelling approaches. The composition and …

Genetic Prediction For Beef In United States, R. L. Willham

3rd World Congress on Genetics Applied to Livestock Production

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.

Genetic Trend In Milk Yield Of Exotic Cattle In India, D. K. Sadana, V. N. Tripathi

3rd World Congress on Genetics Applied to Livestock Production

For the purebred exotic cattle in India the phenotypic and genetic trends were estimated. While the phenotypic trends were positive for all the four farms, the genetic trend was found to be negative for three and positive for one. This necessitates a higher emphasis on progeny testing and sire selection for the improvement of the imported breeds.

Heterosis For Preweaning Traits In Devon-Hereford Crosses Under Temperate Range Conditions, A. L. Gyles, W. H. Upton, K. Hammond, J. M. Thompson, B. Tier

3rd World Congress on Genetics Applied to Livestock Production

Heterosis for gestation length. birth weight. suckling stimulus. weaning weight and preweaning growth was estimated from the first years data of a complete two-breed diallel with the Devon and Hereford breeds. involving 119 calves by 29 sires grown together under temperate grazing conditions at Gunnedah. New South Wales. Australia.

Estimates of heterosis (and average mid-parent values) for gestation length were 0.2% (282.9 days); birth weight 6.5% (32.6kg); suckling stimulus 22.9% (3.51/day); weaning weight 5.9% (155.1kg); and average daily gain to weaning 7.0% (0.6kg/day).

Evaluation Of Inter-Flock Genetic Improvement Programs For Sheep And Goats, G. B. Nicoll, L. Bodin, J. V. Jonmundson

3rd World Congress on Genetics Applied to Livestock Production

Some of the factors involved in inter-flock or breed improvement programs are discussed. Such programs are complicated by the fact that sheep and goats produce a wide range of products under diverse environmental, management and economic circumstances. This leads to problems in defining realistic breeding objectives arising from determining the beneficiaries of genetic improvement, the major genetic decision makers in the industry and the relative importance of the various productive characteristics. The implementation of functional performance recording systems, breeding systems to generate young sire replacements, and testing systems to disseminate genetic improvement, also depend on the conditions under which the …

Reproduction Ability Of Reciprocal Crossbreed Fl Generation By ,T· Sheep Of Mutton Merino Of German Type And By Rahs Of The Breed Kent /Romney Marsh, Bora Cumlivski

3rd World Congress on Genetics Applied to Livestock Production

Using the initial breeds which have been followed since 1970 we are creating a Czech Merino Breed with utility combined of fertility, meat, woll and milk, which might be suitable for conditions in Central Europe.

Selection Applied In The Angus Breeding Scheme Of The New Zealand Land Development And Management Corporation, G. B. Nicoll

3rd World Congress on Genetics Applied to Livestock Production

The Land Development and Management Corporation (LDMC) has estabished an open-nucleus Breeding Scheme within its Rotorua District to breed Angus bulls to cover 20 750 cows and 5 200 heifers. Nucleus herd numbers over the 1976-85 period were 775 cows and 357 heifers, with an average of 101 2-year-old bulls being distributed annually to LDMC herds. From 1976/77, a multiplicative breeding objective was established in the nucleus, accounting for cow and calf weights and net fertility of the cow. Primary selection was applied to yearling bulls and heifers using a selection index combining the calf's data and dam's updated data …

A Preliminary Comparison Of Later Lactation Yields Of Different Friesian Strains In Poland, A. Zarnecki, M. Stolzman

3rd World Congress on Genetics Applied to Livestock Production

Second and third lactation records of F₁ cows from the FAO trial in Poland were used to compare dairy performance of different Friesian strains. Data included only cows that were culled after second and third lactation. In total 2513 second lactation records and 1949 third lactation records were available for analysis.

Least squares analysis of variance was carried out sparately for each lactation. The ranking of strains based an second and third lactiation records was similar as in the first lactation. The North American Holstein, Israeli and New Zealand Friesians were superior in milk and fat production. Due to …

Body Weight Of Horne -Vs- Polled-Sired Awassi Lambs, J. E. Alkass, A. A. Alrawi, A. H. Al-Hillali, H. M. A. Al-Tayy

3rd World Congress on Genetics Applied to Livestock Production

body weights of 120 progeny of horned and polled Awassi rams were compared. Ram group significantly influenced body weight at weaning (p < 0.01), 6 (p < 0.05) and 8 month (p < 0.01) of age in favour of horned-sires. It has been hypothesized that polled gene to exhibit overdominance and / or epistasis for body weight in the heterozygous lambs.

Ram lambs were significantly heavier than ewe lambs at all ages, and single lambs were significantly heavier at birth and weaning. Month of lambing had a significant effect on weaning weight. The effect of age of dam on birth weight was significant.

Calving Difficulty In Rubia Gallega Breed And Its Genetic Improvement, J. Canon, M. Vallejo, S. Dunner

3rd World Congress on Genetics Applied to Livestock Production

Principal causes and their correlationated consequences of calving difficulties in Rubia Gallega beef cattle breed are commented.

Present status of selection objectives and the criteria used are presented, as well as some problems related to the current selection index.

Finally, restriction of birth weight as a solution is criticized and some sire evaluation alternatives are cited.

Comparison Of Five Dam Breeds Under Two Nutritional Environments, C. E. Thompson, S. G. Woods, S. E. Meadows

3rd World Congress on Genetics Applied to Livestock Production

Crossbreeding has become an accepted practice for beef cattle production. Hybrid vigor or heterosis of crosses among breed of English origin, such as Angus, Hereford and Shorthorn have been well documented. Crosses utilizing breeds of European and dairy breeding have not been well documented for beef production, particularly in the Southeastern part of the United States. As most of the Southeastern U.S. is heavily involved in one-calf programs an evaluation of crossbreds involving the use of British, European and dairy breeding is needed. This study is a portion of a comprehensive research project evaluating the performance of 5 dam breed …

Blood Typing Beefalo Cattle, C. J. Stormont, B. G. Morris, Y. Suzuki, J. Dodd

3rd World Congress on Genetics Applied to Livestock Production

In this article we review the species-specific genetic markers in the blood that are currently being used to authenticate the bison ancestry of animals entering the Ancestry Registry of the American Beefalo World Registry. Independently of that program we are also testing for these same genetic markers in a number of private herds in which attempts are being made to develop bison-cattle hybrids that are fully fertile and incorporate desirable traits of both ancestral species.

Breeding Programmes For Multiple Purpose Breeds In Uruguay, R. C. Cardellino, R. W. Ponzoni

3rd World Congress on Genetics Applied to Livestock Production

Uruguay's national sheep performance recording scheme (Flock-Testing Service) is described. Recent developments of the scheme are discussed. The scheme is implemented and supervised by the Uruguayan Wool Secretariat (SUL). Centralization of responsibilities by SUL and continued co-participation of breeders and scientists are identified as the main factors contributing to the scheme's success. It is suggested that Uruguay's Flock-Testing Service combines traditional and scientific breeding methods in a balanced manner, thus assisting with the improvement of the genetic merit of the national flock.

Breeding Improvement Of Swamp Buffalo, Charan Chantalakhana

3rd World Congress on Genetics Applied to Livestock Production

A review of performance of the swamp buffalo concerning reproductive traits, growth and carcass, milk production, and work capacities was presented. The potential for breeding improvement of certain traits was discussed. Breeding objectives and goals to suit the need of Asian smallfarmers were emphasized. Breeding of swamp buffalo for draft and for multi-purpose was discussed. Genetic selection and crossbreeding of the swamp buffalo were reviewed. It was proposed that genetic selection for weight and gain should improve meat production as well as draft ability of the swamp buffalo, while crossbreeding should be limited to experimental scale until crossbred buffaloes have …

Breed Use And Crossbreeding In Goat Production, Maurice Shelton

3rd World Congress on Genetics Applied to Livestock Production

A large portion of the world's 400+ million head of goats cannot be identified as belonging to a specific breed or well defined genetic type. A common definition of a breed might be group of animals which are reasonably distinct and true breeding, can be identified by a name or term and which have an association to maintain and promote the breed. Of the latter requirement is dropped there would still be hundreds of breeds or genotypes of goats on a world basis. Certainly time, space and information available does not permit attempting to treat all of these in this …

Costs And Benefits Of Breed Utilization Strategies In Sheep, William D. Hohenboken

3rd World Congress on Genetics Applied to Livestock Production

Problems involved in choosing appropriate criteria and procedured for economic analyses of breed and mating system evaluation experiments in sheep are described. Literature is reviewed of experiments in which biological or economic efficiency has been investigated. The range in relative economic merit from the poorest to the best group in an experiment typically is from 100 to 120, with values over 140 not uncommon for the best group in an experiment. Heterosis for exonomic traits per ewe mated has ranged from 2% to 26%. Suggestions are presented for consideration in future studies on the economic ramifications of mating system and …

Buffalo For Meat Production, Giovanni De Fanciscis

3rd World Congress on Genetics Applied to Livestock Production

Only very recently buffaloes have been studied deeper for a better breeding and for emphasizing their meat productive potentiality and its physiological, chemical and organolptic qualities.

Very good investigations, conducted mainly in Australia, Bulgaria, Italy, Thailand and Trinidad show in an univocal way, if the buffaloes are reared and fed well, that the daily gain, the percentage of fessing and of the first cut, the organoleptic characteristics are quite similar and sometime also better than those of bovine cattle. The best slaughter tiie is at 14-16 months of age when the live weight is of 350-380 kg with a 52-58 …

Breeding Objectives And Selection Traits For Extensive Beef Cattle Production In The Tropics, D. J. S. Hetzel, G. W. Seifert

3rd World Congress on Genetics Applied to Livestock Production

Breeding objectives are largely determined by market requirements. In the tropics the overall breeding objective can be considered in terms of growth, reproductive rate, carcass quality, adaption and temperament. Growth rate is a simple efficient selection trait. Reasons why potential increases in mature size are not as disadvantageous as in temperate areas are discussed. Reproductive performance has been less important in harsh than benign environments because of the later age of turnoff and higher drought risk of fertile cows. Current market trends towards younger slaughter stock highlight the need to identify marker traits in bulls for cow fertility. Adaptive traits …

Economic Evaluation Of Breeding Objectives In Dairy Cattle. Intensive Specialized Milk Production In Temerate Zones., R. E. Pearson

3rd World Congress on Genetics Applied to Livestock Production

In previous world congresses (Cunningham, 1974; Pearson, 1982) methods of estimating weights and choosing traits to include in the selection of objectives were discussed. A more recent discussion of objection functions for breeding decisions is in Allaire and Thraen (1985). This paper will focus more on the specific traits to be included in the selection objective for intensive milk production in temperate zones and on experimental evidence of relative economic importance.

Criteria For Evaluating A Selection Screne: Some Proposals, J. M. Elsen, L. Bodin, G. Ricordeau

3rd World Congress on Genetics Applied to Livestock Production

It is possible to describe a realized selection by means of an indicator, f(x): probability for an individual of value x to be selected. Various models for this indicator are proposed, in the univariate case, and on the assumption that individuals are ranked on a linear index of measured variables. Estimators are defined on the basis of these models for rating traits controlled during selection. A numeric example with ewes is given.

Economic Evaluation Of Breeding Objectives For Milk And Beef Production In Tropical Environments, F. E. Madalena

3rd World Congress on Genetics Applied to Livestock Production

The influence of some elements of tropical milk production systems on breeding objectives is discussed. Expansion of demand for milk and meat should be expected from increased population and income growth. Relative commercial value of milk fat may be strongly influenced by government policies regulating to proportion of liquid milk consumed. Calf production is an integral part of cow performance under the common practices of hand milking and suckling. Milk letdown may be an important trait for milking in modern dairy parlours. Experimental economic evaluations have referred mainly to comparisons of breeds and crosses, indicating that European × zebu crosses …

Economic Evaluation Of Breeding Objectives For Milk And Beef Production In Temperate Zones, E. Niebel

3rd World Congress on Genetics Applied to Livestock Production

Intensive milk and beef production is common to the European agricultural areas due to a high density of population. Milk and beef traits are involved in most breeding objectives of dual-purpose cattle.

Various dual-purpose cattle popluations cover a wide range of economic weighting of milk and beef. The optimal weights of milk and beef characters depend on the marginal change in profit, and the time and number of realizations of genetic improvement of the traits. Over-production prevails in the agriculture equilibrium model of Linear Programming can be used to reliably evaluate most of the economic weights of dairy and beef …

Economic Selection Indices For Lean Meat Production In Sheep, G. Simm

3rd World Congress on Genetics Applied to Livestock Production

Economic selection indices were derived for terminal sire sheep breeds or strains, using physical and financial results from New Zealand export lamb-producing flocks. The aggregate breeding value comprised carcass lean weight and carcass total fat weight. Index measurements were live weight, ultrasonic fat depth and ultrasonic muscle depth. Economic values of lean weight and fat weight were estimated to be NZ $5. 07 and NZ $-3.72 per kg, respectively. The s.d. of the aggregate breeding value was NZ $3.20 and the correlation between the full index and the aggregate breeding value was 0.23. The expected economic response to selection on …