CORRELATED RESPONSE IN BIRTH WEIGHT, GROWTH RATE AND CARCASS MERIT UNDER SINGLE-TRAIT SELECTION FOR YEARLING WEIGHT IN BEEF SHORTHORN CATTLE

1974 ◽  
Vol 54 (2) ◽  
pp. 117-125 ◽  
Author(s):  
B. BECH ANDERSEN ◽  
H. T. FREDEEN ◽  
G. M. WEISS
Keyword(s):  
Birth Weight ◽  
Selection Response ◽  
Correlated Response ◽  
Weight Growth ◽  
Cumulative Selection ◽  
Selection For ◽  
Carcass Merit ◽  
Least Squares Estimates ◽  
Daily Gain

Data for male calves from the most recent 5 yr of a long-term (11 yr) selection experiment with beef Shorthorn cattle were analyzed to calculate the direct and correlated response of intensive selection for yearling weight on growth and carcass characteristics. Least squares estimates of line differences (select vs. control) for the final year indicated cumulative selection responses [Formula: see text] of 41.5 and 46.2 kg in yearling weight for the two herds. Associated with this selection response in the two herds were increases in birth weight (3.6 and 3.0 kg; [Formula: see text]) in weaning weight (16.2 and 7.8 kg; [Formula: see text] and NS) and daily gain from birth to 10 mo of age (104 and 118; [Formula: see text]). The indirect effects on carcass merit were higher percentage of bone (0.6 and 0.7; [Formula: see text]), and a reduced lean/bone ratio (−0.19 and −0.11; [Formula: see text] and NS). Other differences were not statistically meaningful. The heritabilities for growth characters calculated as son/sire regressions were: birth wt 0.30 ± 0.13; weaning wt 0.34 ± 0.22; yearling wt 0.47 ± 0.23; weaning wt/yearling 0.38 ± 0.21; and daily gain 0.22 ± 0.16. For the most important carcass merit measurements the heritabilities, calculated as half-sib correlations, were: % lean 0.03 ± 0.21; % bone 0.86 ± 0.29; % fat (ext.) 0.01 ± 0.21; % fat (int.) 0.19 ± 0.23; lean/bone 0.72 ± 0.28; and hindquarter wt/forequarter wt 0.24 ± 0.24.

MASS SELECTION FOR POST-WEANING GROWTH IN SWINE. V. CORRELATED RESPONSE OF REPRODUCTIVE TRAITS AND PRE-WEANING GROWTH

1976 ◽  
Vol 56 (4) ◽  
pp. 791-801
Author(s):  
I. GARNETT ◽  
G. W. RAHNEFELD
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
Reproductive Traits ◽  
Correlated Response ◽  
Mass Selection ◽  
Gestation Length ◽  
Control Line ◽  
Weaning Weight ◽  
Selection For ◽  
Daily Gain

Female reproductive performance and pre-weaning survival and growth were examined in a population of swine over 11 generations of selection for post-weaning average daily gain (ADG). Three separate breeding groups were used: (1) a Lacombe (L) line selected each generation for ADG, (2) a Yorkshire control (Y) line, and (3) a crossbred Lacombe × Yorkshire group (LY) generated each generation from the L and Y lines. Breeding group differences were evident for litter size, perinatal mortality, pre-weaning mortality, gestation length, birth weight, pre-weaning average daily gain (PreADG) and weaning weight. Selection did not affect number born, number born alive, number weaned or birth weight. When the values for the L line were expressed as a deviation from the control, pre-weaning mortality showed an increase. The increase appeared to be due to a decrease in the control rather than an increase in the L line. Gestation length showed a negative response to selection. As in the case of pre-weaning mortality, the response appeared to be a reflection of the instability of the control line. Genetic gains in PreADG of 0.004 kg/day/generation were realized in both the L line and LY group. Correspondingly, responses of 0.18 and 0.19 kg/generation were realized for weaning weight in the L line and LY group.

CHANGES IN BEEF CATTLE PERFORMANCE AFTER TEN YEARS OF YEARLING WEIGHT SELECTION

1990 ◽  
Vol 70 (4) ◽  
pp. 1017-1028 ◽  
Author(s):  
J. C. OLTHOFF ◽  
G. H. CROW ◽  
G. W. RAHNEFELD
Keyword(s):  
Beef Cattle ◽  
Average Daily Gain ◽  
Age Distribution ◽  
Selection Response ◽  
Correlated Response ◽  
Control Line ◽  
Short Period ◽  
Selection For ◽  
The Difference ◽  
Daily Gain

Selection for yearling weight, a trait with relatively high heritability, in beef cattle should lead to a significant response in a short period of time. Changes should also occur in correlated and component traits. Data from 10 yr of yearling weight selection in beef Shorthorn cattle were used to quantify the response in correlated calf and cow traits. Selection response was measured as the difference between the performance of the select line and a corresponding control line. Annual response to selection for bull and heifer calves, respectively, averaged 5.1 and 4.3 kg for yearling weight, 2.1 and 1.6 kg for weaning weight, 0.3 and 0.2 kg for birth weight, 0.016 and 0.014 kg d−1 for post-weaning average daily gain and 0.010 and 0.007 kg d−1 for preweaning average daily gain. There were no significant changes in calf survival or cow reproductive performance. Cow weights increased 4.5 kg yr−1 for 2-yr-old heifers, similar to the yearling weight response, but only 1.3 kg yr−1 for all cows because of the time delay caused by the age distribution of the breeding herd. Yearling weight increases were brought about by increases in the individuals genetic potential for gain, primarily postweaning. Response to yearling weight selection would be relatively easy to achieve for beef producers. Some additional costs would be incurred, however, and the environmental effects, which were large, would have to be monitored. Key words: Beef cattle, yearling weight, selection response, correlated response

scholarly journals The Impact of Selection using Residual Average Daily Gain and Marbling EPDs on Growth Performance and Carcass Traits in Angus Steers

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
T. R. Krause ◽  
E. R. Moore ◽  
J. Duggin ◽  
J. R. Segers ◽  
T. D. Pringle
Keyword(s):  
Growth Performance ◽  
Feed Efficiency ◽  
Average Daily Gain ◽  
Backfat Thickness ◽  
Feeding Trial ◽  
Body Weights ◽  
Selection For ◽  
Carcass Merit ◽  
The Impact ◽  
Daily Gain

ObjectivesProfitability in the beef industry has narrow margins regulated by revenue from output traits like growth and carcass merit, but profitability is also largely impacted by input expenses like feed costs. Selecting for improvements in feed efficiency during the finishing phase, one of the most feed intensive segments of the industry, can help to mitigate those input costs. This study compared growth performance, feed efficiency, body composition, and carcass characteristics in Angus steers (n = 321) from bulls divergently selected for feed efficiency and marbling.Materials and MethodsAngus sires were selected based on high (10th percentile or better) and low (85th percentile or worse) residual average daily gain (RADG) EPD as well as high (fifth percentile or better) and average (near 50th percentile) marbling (MARB) EPD. These criteria resulted in a 2 × 2 factorial design with four breeding lines: high RADG/high MARB, high RADG/average MARB, low RADG/high MARB, low RADG/average MARB. Data were analyzed using MIXED procedures of SAS with RADG and MARB as main effects. Significance was set at α = 0.05. Generation was also analyzed, where generation one (GEN1) steers were from a selected sire while generation two (GEN2) steers were from a selected sire and a selected dam.ResultsUltrasound and carcass data revealed no differences (P ≥ 0.12) in 12th rib backfat thickness from weaning through slaughter for the RADG EPD groups. Yield grade and dressing percent did not differ (P ≥ 0.56) across RADG or MARB groups. At the beginning and end of the feeding trial, the high RADG (P ≤ 0.02) group had larger ultrasound ribeye area (REA) than the low RADG group. Carcass REA tended (P = 0.08) to be larger in the high versus low RADG steers. During the feedlot trial and through slaughter, body weight was heavier (P ≤ 0.006) for the high versus low RADG steers but did not differ (P ≥ 0.44) across MARB EPD. Feed efficiency measures did not differ (P ≥ 0.32) across RADG or MARB groups apart from the tendency (P = 0.08) for residual feed intake to be lower in the high versus low RADG steers. Marbling scores differed (P ≤ 0.04) across RADG and MARB groups with the low RADG steers and the high MARB steers having improved marbling. The quality grade distribution across MARB EPD revealed that the average MARB steers graded 73% Choice and 25% Prime while the high MARB steers graded 56% and 42%, respectively. Slice shear force did not differ (P ≥ 0.32) across RADG or MARB EPD. Body weights tended (P = 0.06) to be heavier at the start of the feeding trial for GEN1 versus GEN2 steers. Total gain, average daily gain, and feed to gain (F:G) differed by generation (P ≤ 0.007) with increased rates of gain and reduced F:G in the GEN2 versus GEN1 steers. Body weights did not differ (P = 0.72) across GEN at the end of the feeding trial. Backfat thickness at the start and end of the feedlot phase was less (P ≤ 0.03) and marbling score was improved (P = 0.02) in the GEN2 versus GEN1 steers, respectively.ConclusionThese results suggest that selection using RADG EPD has negligible impacts on meat quality; and that progress in selection for efficiency can be achieved while advancing carcass quality and value. Furthermore, continued divergent selection for feed efficiency and marbling has the potential to improve feed efficiency through advancements in the rate of gain, while enhancing carcass merit through marbling.

scholarly journals LONG-TERM SELECTION RESPONSE FOR 12-DAY LITTER WEIGHT IN MICE

Genetics ◽  
1972 ◽  
Vol 72 (1) ◽  
pp. 129-142
Author(s):  
E J Eisen
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Half Life ◽  
Selection Process ◽  
Selection Response ◽  
Exponential Model ◽  
Correlated Response ◽  
Term Selection ◽  
Litter Weight

ABSTRACT Long-term selection for increased 12-day litter weight in two replicate lines (W2, W3) of mice resulted in an apparent selection limit at about 17 generations. Quadratic polynomial and exponential models were fitted to the data in order to estimate the plateaued response and half-life of the selection process. Using the polynomial results, the half-life estimates were 4.5 and 8.6 generations for W2 and W3, respectively. The plateaued responses were 5.1 and 5.8 g which, when expressed in phenotypic standard deviation units, became 1.1 and 1.3. The exponential model provides similar estimates. A negative association between 12-day litter weight and fitness was not considered to be an adequate explanation for the plateau since there was no decrease in fertility of the selected lines. Evidence that exhaustion of genetic variability was not the cause of the plateau came from the immediate response to reverse selection. It was proposed that the plateau may be due to a negative genetic correlation between direct and maternal genetic effects, which would be expected to occur after many generations of selection. There were positive correlated responses in both replicates for adult body weight, which was in agreement with the positive genetic correlation between preweaning and postweaning body weight. The expected positive correlated response for number born was realized in only one of the replicates.

Estimates of genetic parameters for pre-weaning and post-weaning growth traits of Chios lambs

1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Heritability Estimate ◽  
Weaning Weight ◽  
Phenotypic Correlations ◽  
Selection For ◽  
Daily Gain

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.

ESTIMATES OF GENETIC CORRELATIONS AMONG CERTAIN CARCASS AND PERFORMANCE TRAITS IN SWINE

1968 ◽  
Vol 48 (1) ◽  
pp. 1-6 ◽  
Author(s):  
G. L. Roy ◽  
W. J. Boylan ◽  
M. E. Seale
Keyword(s):  
Birth Weight ◽  
Genetic Correlation ◽  
Genetic Relationships ◽  
Carcass Traits ◽  
Genetic Correlations ◽  
Development Project ◽  
Carcass Trait ◽  
Selection For ◽  
And Performance ◽  
Daily Gain

Data from a swine breed development project provided estimates of the genetic correlation among six performance and carcass traits. The data from the new breed, called Managra, were obtained over a 7-year period. Most genetic relationships examined were such that selection for improvement of one trait would yield a favorable improvement in another. Both carcass backfat and live backfat probe were found to be negatively correlated with area of loin eye and length of carcass. A positive genetic correlation was found between post-weaning daily gain and loin eye area. A high positive genetic correlation was found between birth weight and loin eye area. An unfavorable association involved a positive genetic correlation between birth weight and backfat.Correction factors for effect of carcass weight on the magnitude of carcass trait measurements and differences in means between sexes were obtained.Heritability of the traits was estimated by paternal half-sib correlation. The estimates for carcass traits were moderately high and agree well with most other estimates reported in the literature.

Parturition induction two days prior to term decreases birth weight and lactational growth, but not piglet maturity, health or post-weaning growth

2009 ◽  
Vol 89 (2) ◽  
pp. 219-228 ◽  
Author(s):  
G L Olson ◽  
L. Robine ◽  
L B Rosengren ◽  
C D Baker ◽  
M. Duggan ◽  
...  
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Clostridium Perfringens ◽  
Prostaglandin F2α ◽  
Liver Glycogen ◽  
Gestation Length ◽  
Weight Growth ◽  
And Performance ◽  
The Impact

Premature parturition induction may adversely affect postnatal health and performance. The objective of this study was to evaluate the impact of cloprostenol induction 2 d prior to term on piglet maturity (liver glycogen), postnatal productivity (birth weight, growth rate), and health (morbidity, mortality, passive antibody, fecal Clostridium perfringens). Two hundred and sixteen pregnant sows and their progeny (2827 piglets) were assigned to the study. Induction decreased gestation length 2.1 d (P < 0.0001), birth weight 107.2 g pig-1 (P = 0.0004), lactational growth 10.1 g d-1 (P = 0.05), and day 16 weight 0.30 kg pig-1 (P < 0.05). Liver glycogen concentration was 71.2 µg g-1 higher in the stillborns of induced sows (P = 0.03), suggesting the pre-term sows were catabolic. No group differences in post-weaning growth rate, pre-weaning mortality or morbidity, passive antibody transfer or fecal Clostridium perfringens level were found. Reduced lactational growth appeared attributable to the reductions in gestation length and birth weight, rather than in piglet maturity. In spite of reducing lactational growth and body weight at 16 d of age, the administration of cloprostenol 2 d prior to term, under the conditions of this study, resulted in no measureable long-term health or performance consequences. Key words: Porcine, parturition-induction, cloprostenol, prostaglandin F2α, glycogen, Clostridium perfringens

scholarly journals Selection for Increased Budbreak in Apple

2003 ◽  
Vol 128 (3) ◽  
pp. 363-373 ◽  
Author(s):  
Iwan F. Labuschagné ◽  
J.H. Louw ◽  
Karin Schmidt ◽  
Annalene Sadie
Keyword(s):  
Genetic Variance ◽  
Screening Method ◽  
Selection Response ◽  
Significant Response ◽  
Correlated Response ◽  
Realized Heritability ◽  
Early Screening ◽  
Adult Trees ◽  
Selection For ◽  
Combined Selection

Significant response to selection for budbreak number (NB) based on data recorded on 1-year-old shoots of young apple (Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.) seedlings (Expt. I) and branches from adult seedling trees (Expt. II) has been demonstrated in clonally propagated seedling trees. Between family variation for NB was low and masked by year × family interaction effects. Realized heritability for NB was estimated as 40% to 60%. Correlated response in uniformity and position of budbreak, and in the number and length of side shoots, was found. Association between the time of budbreak (TB) and NB, according to midparent and cross groupings, and according to the parental means, indicate a positive genetic correlation between these traits. Where data on adult trees were used as a measure of selection response and tested on young clonal trees, significant response and genetic variation was shown, confirming the presence of utilizable genetic variance and that this procedure may be successfully applied as an early screening method for increased budbreak in adult trees. Combined selection utilizing genetic variance between crosses as well as within crosses is proposed as the best procedure to increase the frequency of seedlings with increased budbreak and to improve adaptation to low winter chilling conditions.

Selection Response in Natural Populations

2018 ◽  
Author(s):  
Bruce Walsh ◽  
Michael Lynch
Keyword(s):  
Natural Populations ◽  
Selection Response ◽  
Correlated Response ◽  
Sources Of Error ◽  
True Target ◽  
Change In The Mean ◽  
The Mean ◽  
Actual Target ◽  
Long Term Studies

The breeder's equation often fails when applied to natural populations. In large part, this likely occurs because the assumed trait is not the actual target of selection. A within-generation change in the mean of a suggested target trait can arise as a correlated response from selection acting elsewhere. This chapter examines sources of error in the breeder's equation and approaches that attempt to determine if an assumed trait is actually the true target of selection. It also reviews a number of long-term studies from natural populations and examines possible sources for the failure of most of these studies to conform to the expectations of the breeder's equation.

scholarly journals Long-term selection for a quantitative character in large replicate populations of Drosophila melanogaster: 1. Response to selection

1980 ◽  
Vol 35 (1) ◽  
pp. 1-17 ◽  
Author(s):  
B. H. Yoo
Keyword(s):  
Drosophila Melanogaster ◽  
Phenotypic Variability ◽  
Selection Response ◽  
Quantitative Character ◽  
Response Patterns ◽  
Total Response ◽  
Term Selection ◽  
Bristle Number ◽  
Selection For

SUMMARYThe response to long-term selection for increased abdominal bristle number was studied in six replicate lines of Drosophila melanogaster derived from the sc Canberra outbred strain. Each line was continued for 86–89 generations with 50 pairs of parents selected at an intensity of 20%, and subsequently for 32–35 generations without selection. Response continued for at least 75 generations and average total response was in excess of 36 additive genetic standard deviations of the base population (σA) or 51 times the response in the first generation. The pattern of longterm response was diverse and unpredictable typically with one or more accelerated responses in later generations. At termination of the selection, most of the replicate lines were extremely unstable with high phenotypic variability, and lost much of their genetic gains rapidly upon relaxation of selection.The variation in response among replicates rose in the early phase of selection to level off at approximately 7·6 around generation 25. As some lines plateaued, it increased further to a level higher than would be accommodated by most genetic models. The replicate variation was even higher after many generations of relaxed selection. The genetic diversity among replicates, as revealed in total response, the individuality of response patterns and variation of the sex-dimorphism ratio, suggests that abdominal bristle number is influenced potentially by a large number of genes, but a smaller subset of them was responsible for selection response in any one line.

Sign in / Sign up

Export Citation Format

Share Document