Selection indices for Canadian beef production using specialized sire and dam lines

1994 ◽  
Vol 74 (3) ◽  
pp. 419-424 ◽  
Author(s):  
M. D. MacNeil ◽  
S. Newman

Relative economic values and literature estimates of genetic and phenotypic variances and covariances were used to develop selection indices for specialized maternal and terminal strains of beef cattle. The envisioned commercial production setting used three maternal strains mated in rotation. Yearling heifers were mated to a terminal sire strain (M3) to minimize dystocia and neonatal mortality without closely monitored calving. Mature cows were bred to a second terminal strain (TX) to produce market progeny. Acccuracies for all indices were low: 0.22, 0.22 and 0.19 for the maternal strains, M3 and TX, respectively. Predicted correlated responses to index selection were not economically favorable for all traits within strain but were offsetting between strains. At the production system level, genetic improvement in profitability resulted from all traits except feed conversion. Fertility and calf survival were improved in all strains. Direct genetic potential for growth was reduced in the maternal strains but was increased in TX and to a lesser degree in M3. There was a tradeoff between maternal and terminal strains in responses of carcass traits. Maternal strains increased in dressing percentage and decreased in cutability, while M3 and TX decreased in dressing percentage and increased in cutability. Arduously slow improvement in profitability is anticipated: $1.07 per breeding female per unit of selection response. Key words: Beef cattle, selection program, selection index

1994 ◽  
Vol 74 (3) ◽  
pp. 411-417 ◽  
Author(s):  
M. D. MacNeil ◽  
S. Newman ◽  
R. M. Enns ◽  
J. Stewart-Smith

A deterministic herd-level model was developed to simulate profit (income minus expense) from 100 beef cows in western Canada. The cow-herd was composed of three synthetic strains (M1, M2 and M4) mated in rotation and at equilibrium with respect to age and genotype. Two synthetic "terminal sire" strains (M3 and TX) were also simulated. Heifers were mated with M3 to minimize dystocia when calving at 2 yr of age. Cows greater than 5 yr of age were bred to TX. Baseline economic and biological data were obtained from Beefbooster breeders. Endpoints considered were weaned calves, backgrounded steer and heifer calves, finished steers and heifers, and carcass weight and grade. Variable costs included feed consumed by the cow-herd (76% of variable costs to weaning), non-feed items to weaning, and feed consumed by market progeny after weaning. Relative economic values (âi) were changes in profit ensuing from unit changes of the baseline strain specific biological characteristics. Elements of â were economic values for: cow weight, kg; male and female fertility, %; calf survival, %; direct and maternal effects on weaning weight, %; rates of gain on backgrounding and finishing rations, kg/d; feed conversion, dressing percent, % A grade and carcass cutability, %. For M1, M2 and M4 â was: [− 0.11 0.87 1.31 0.90 0.06 0.06 1.90 16.27 − 0.61 2.78 0.18 4.81]; for M3 â was: [0.00 0.38 0.00 0.28 0.03 0.00 0.95 4.74 − 0.21 0.92 0.06 1.67]; and for TX â was: [0.00 1.90 0.00 0.89 0.06 0.00 1.32 16.07 − 0.64 2.85 0.19 5.10] at the carcass endpoint. Direct and maternal weaning weight had greater âi at weaning than at later endpoints and âi for feed conversion increased in magnitude as time on feed increased. Key words: Beef cattle, selection program, breeding objective


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 531
Author(s):  
Januarius Gobilik ◽  
Stephen Todd Morris ◽  
Cory Matthew

Metabolic energy budgeting (MEB) was used to evaluate evolution over 30 years (1980–1981 to 2010–2011) in New Zealand southern North Island ‘hill country’ sheep and beef cattle systems. MEB calculates energy required by animals for body weight maintenance, weight gain or loss, pregnancy, and lactation to estimate the system feed demand and thereby provide a basis for calculating feed conversion efficiency. Historic production systems were reconstructed and modeled using averaged data from industry surveys and data from owners’ diaries of three case-study farms and reviewed for patterns of change over time. The modeling indicated that pasture productivity was 11% lower and herbage harvested was 14% lower in 2010–2011 than in the early 1980s. This productivity decline is attributable to warmer, drier summer weather in recent years. However, primarily through increased lambing percentage, feed conversion efficiency based on industry data improved over the study period from 25 to 19 kg feed consumed per kg lamb weaned, while meat production rose from 137 to 147 kg per ha per year. Similar improvements were observed for the three case farms. The New Zealand MEB model was found effective for analysis of tropical beef production systems in Sabah, Malaysia.


1996 ◽  
Vol 1996 ◽  
pp. 111-111
Author(s):  
V.C. Flamarique ◽  
R.M. Lewis ◽  
G. Simm

Excess fat in lamb is regarded as an important reason for less lamb meat being purchased by consumers. This has encouraged the development and use (particularly in Terminal Sire breeds) of selection indices that can identify animals that will sire leaner progeny. These indices usually include live weight and in vivo predictors of body composition, such as an ultrasonic measurement of muscle and fat depth, as selection criteria (Simm and Dingwall, 1989). But the usefulness of such in vivo measurements as predictors of carcass composition depends on the correlation between, and the variation in, live and carcass measures. The objectives of this study were to determine the strength of the relationship between ultrasound and dissection measures of carcass composition, and the degree of genetic variation in these measures, in crossbred progeny of Suffolk rams.


2017 ◽  
Vol 42 (3) ◽  
pp. 147
Author(s):  
C. K. N. Zebua ◽  
M. Muladno ◽  
P. H. Siagian

The objectives of this study was to analyze the comparative ability of animal genetic, using evaluation of production that has important economic traits including Landrace, Yorkshire, and Duroc breeds of swine. A total of 49 swine consist 15 boars and 34 gilts, with average body weight of 18.50-21.50kg were used in this research. All of samples were raised in the same pen and feeding management. This research used the experimental method of Completely Randomized Design involving three treatments of animal breeds including Landrace, Yorkshire, and Duroc breeds. The data were analyzed by using analysis of covariance procedur General Linier Model and Least Square Means test. Boars and gilts were analyzed in separated data. The result showed that the effect of breed was significantly associated for all traits, but not for boars feed intake. The overall, Yorkshire and Landrace performed better than Duroc for average daily gain, feed conversion ratio, selection index, and age at 90 kg body weight. However, Duroc boars and gilts had the thinnest backfat followed by Yorkshire and Landrace.


2018 ◽  
Vol 63 (No. 10) ◽  
pp. 408-418 ◽  
Author(s):  
Z. Krupová ◽  
M. Wolfová ◽  
E. Krupa ◽  
J. Přibyl ◽  
L. Zavadilová

The objective of this study was to calculate economic weights for ten current breeding objective traits and for four new traits characterising claw health and feed efficiency in Czech Holstein cattle and to investigate the impact of different selection indices on the genetic responses for these traits. Economic weights were estimated using a bio-economic model, while applying actual (2017) and predicted (2025) production and economic circumstances. For the actual situation, the economic weights of claw disease incidence were –100.1 € per case, and those of daily residual feed intake in cows, breeding heifers, and fattened animals were –79.37, –37.16, and –6.33 €/kg dry matter intake per day, respectively. In the predicted situation, the marginal economic weights for claw disease and feed efficiency traits increased on average by 38% and 20%, respectively. The new traits, claw disease incidence and daily residual feed intake, were gradually added to the 17 current Holstein selection index traits to improve the new traits. Constructing a comprehensive index with 21 traits and applying the general principles of the selection index theory, a favourable annual genetic selection response was obtained for the new traits (–0.008 cases of claw disease incidence and –0.006 kg of daily residual feed intake across all cattle categories), keeping the annual selection response of the most important current breeding objective traits at a satisfactory level (e.g., 73 kg of milk yield per lactation, 0.016% of milk fat). Claw health and feed efficiency should be defined as new breeding objectives and new selection index traits of local dairy population.


1995 ◽  
Vol 25 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Claudia Helena Tagliaro ◽  
Maria Helena Lartigau Pereira Franco ◽  
Werner Meincke ◽  
Gilberto Silva

Fourteen protein systems coded by 15 structural loci were typed by horizontal electrophoresis to determine possible associations betweem the protein phenotypes and productive traits in Landrace (N=109), Largo White (N= 116) and Duroe (N=57) pigs, reared in Southern Brazil. Signiticant associations between protein phenotypes and production traits were detected. The most consistent interaction were observed between two protein systems (phosphogluconate dehydrogenase - Pgd and Hemopexin -Hpx) and at least one of the four performance variables considered. In Duroc breed, the Pgd phenotypes were associated with daily weight gain (P < 0.01), feed conversion ratio (P < 0.01) and selection index (P < 0.001), while in Landrace significant associations were observed only with feed convertion ratio (P < 0.05). The Hpx phenotypes were associated with daily weight gain (P < 0.05) and backfat thickness (P < 0.05) in Large White and with this last variable (P < 0.01) and selection index (P < 0.05) in Duroc pigs. Since these results had not been reported previously, turther studies are need to confirm these associations.


2010 ◽  
Vol 10 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Henry Fred Ojulong ◽  
Maryke Tine Labuschagne ◽  
Liezel Herselman ◽  
Martin Fregene

The cassava breeding scheme currently used is long, because initial stages concentrate mainly on improving yield, with root quality selection following later. To shorten the scheme, yield and root quality should be selected simultaneously, starting at the seedling nursery. In this study, a nursery comprising of eight cassava families and 1885 seedlings developed from parents adapted to three major agro-ecologies, were evaluated for yield related traits in Colombia. Percentage dry matter content (DMC) and harvest index produced similar ranking of the parents. Tuber yield, weight, and number showed potential of increasing yield through conventional breeding. A selection index including fresh root yield, percentage DMC, root weight and roots per plant, with heavier weights being assigned to root weight and roots per plant, should be used.


2004 ◽  
Vol 44 (5) ◽  
pp. 405 ◽  
Author(s):  
J. H. J. van der Werf

Residual feed intake is a linear function of feed intake, production and maintenance of liveweight, and as such is an attractive characteristic to use to represent production efficiency. The phenotypic and genetic parameters of residual feed intake can be written as a function of its constituent traits. Moreover, selection indices containing the constituent traits are equivalent with an index that includes residual feed intake. Therefore, definition of the term residual feed intake may be useful to interpret variation in production efficiency, but it does not help in obtaining a better selection response than selection on constituent traits alone. In fact, multiple trait genetic evaluation of constituent traits rather than residual feed intake is likely to be more accurate as this more appropriately accommodates different models for the constituent traits and missing data. For residual feed intake to reflect true biological efficiency in growing animals, it is important that feed intake and liveweight are accurately measured. Accounting for growth and body composition would significantly help in revealing between-animal variation in feed utilisation. Random regression models can be helpful in indicating variation in feed efficiency over the growth trajectory.


1963 ◽  
Vol 43 (1) ◽  
pp. 72-85 ◽  
Author(s):  
R. N. Plank ◽  
R. T. Berg

Four trials, involving 124 pigs, were conducted to study the effects of differing planes of nutrition on swine characteristics and to study the relative response of specific genetic groups of pigs to these differing planes. Seasonal and sex effects were also evaluated. Equalized limited feeding to a scale of 75 per cent of the U.S. N.R.C. recommended levels for bacon hogs was compared to liberal feeding wherein pigs were fed to appetite three times daily and to ad libitum feeding.Winter-fed pigs grew slower, were less efficient, had a higher dressing percentage and shorter carcasses than summer-fed pigs.As the plane of nutrition increased, average daily gains increased, feed conversion ratios were correspondingly inferior, dressing percentage rose, backfat thickness increased and area of loin and total Record of Performance score decreased.Females outgained barrows under equalized limited feeding, whereas barrows outgained females at a similar feed requirement by eating more feed under liberal feeding. Female carcasses were superior to those of barrows with a tendency for the differences to be greater under the equalized limited feeding system.Genotype × plane of nutrition interactions were significant for average daily feed consumed (P <.05), average daily gain (P <.01), length (P <.05), and total R.O.P. score (P <.01). Under equalized limited feeding pigs with the ability to gain both rapidly and efficiently tended to produce superior carcasses while under liberal feeding rapid gains seemed to reflect mainly increased feed consumption and a trend toward inferior feed conversion and fatter carcasses.


Author(s):  
G Simm ◽  
W S Dingwall ◽  
S V Murphy ◽  
J FitzSimons ◽  
W R Brown

It is likely that returns from lamb production in future will depend, much more than at present, on producing leaner carcasses. There are several short-term changes in management which could produce leaner carcasses. However, In the longer term genetic Improvement, particularly by within-breed selection In terminal sire breeds, is likely to provide permanent, cumulative and cost-effective benefits In carcass composition. In the early 1980s a research project was started at the Edinburgh School of Agriculture, using Suffolk sheep, to examine the genetic potential for Improving carcass composition In terminal sires. The work commenced with an evaluation of techniques for in vivo measurement of carcass composition (Simm, 1987) and derivation of selection indices to incorporate In vivo measurements (Simm and Dingwall, 1989). Since 1985 In vivo measurement and Index selection have been practised In the experimental flock, which now numbers about 220 ewes. This paper reports the interim results of selection.


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