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

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.

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. IV. SELECTION RESPONSE AND CONTROL POPULATION STABILITY

1976 ◽  
Vol 56 (4) ◽  
pp. 783-790
Author(s):  
G. W. RAHNEFELD ◽  
I. GARNETT
Keyword(s):  
Additive Genetic Variance ◽  
Average Daily Gain ◽  
Selection Response ◽  
Relative Magnitude ◽  
Control Population ◽  
Mass Selection ◽  
Gene Effects ◽  
Selection For ◽  
And Control ◽  
Daily Gain

Recurrent mass selection for post-weaning average daily gain was practiced for 11 generations in a population of Lacombe swine. Response to selection was assessed from predicted response, 0.241 ± 0.023 kg; observed response, 0.146 ± 0.018 kg; estimated heritability, 0.327 ± 0.031; and realized heritability, 0.198 ± 0.016. Observed response was estimated to be 0.61 of the predicted. Examination of additive genetic variance, selection differentials, drift variance, inbreeding and regression of post-weaning average daily gain on generation time indicated that the pedigreed Yorkshire control population served as an adequate control. Gene effects were not found to be dependent on the sex of the organism as assessed by the genetic correlation between sexes, covariance between half-sib family means and the relative magnitude of parent–offspring-based estimates of heritability.

MASS SELECTION FOR POSTWEANING GROWTH IN SWINE. III. CORRELATED RESPONSE IN WEANING WEIGHT AND FEED EFFICIENCY TO RECURRENT SELECTION FOR POSTWEANING AVERAGE DAILY GAIN IN SWINE

1973 ◽  
Vol 53 (2) ◽  
pp. 173-178
Author(s):  
G. W. RAHNEFELD
Keyword(s):  
Genetic Correlation ◽  
Feed Efficiency ◽  
Average Daily Gain ◽  
Direct Selection ◽  
Correlated Response ◽  
Mass Selection ◽  
Total Response ◽  
Weaning Weight ◽  
Selection For ◽  
Daily Gain

Correlated response in weaning weight and feed efficiency were estimated for a genetically variable population of swine selected during nine generations for postweaning average daily gain. Total response in weaning weight to direct selection for gain was 0.03 kg per generation. This was 3.1% of the predicted response. The estimate of genetic correlation between postweaning average daily gain and weaning weight was found high and positive (> 1). Total response in feed efficiency to direct selection for gain was −0.58 kg per generation. This was 10% of the predicted response. The estimate of genetic correlation between postweaning gain and feed efficiency was −0.35.

RESPONSES TO INDEX SELECTION FOR REDUCED BACKFAT THICKNESS AND INCREASED GROWTH RATE IN SWINE

1990 ◽  
Vol 70 (3) ◽  
pp. 973-977 ◽  
Author(s):  
R. M. McKAY
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Average Daily Gain ◽  
Selection Response ◽  
Backfat Thickness ◽  
Index Selection ◽  
Selection Differential ◽  
Differential Selection ◽  
Selection For ◽  
Daily Gain

Selection resulted in a decrease in probed backfat thickness and a negligible change in postweaning average daily gain. Realized heritabilities in the Yorkshire and Hampshire select lines were 0.41 ± 0.04 and 0.34 ± 0.18, respectively, for probed backfat thickness and 0.38 ± 0.43 and 0.65 ± 0.19, respectively, for postweaning average daily gain. Key words: Swine, selection differential, selection response, backfat, growth rate

MASS SELECTION FOR POSTWEANING GROWTH IN SWINE. VI. MEANS, HERITABILITIES, GENETIC AND PHENOTYPIC CORRELATIONS, AND CORRELATED RESPONSE OF CARCASS TRAITS

1983 ◽  
Vol 63 (1) ◽  
pp. 49-58 ◽  
Author(s):  
G. W. RAHNEFELD ◽  
R. L. CLIPLEF ◽  
I. GARNETT ◽  
R. M. McKAY
Keyword(s):  
Average Daily Gain ◽  
Carcass Traits ◽  
Correlated Response ◽  
Mass Selection ◽  
Correlated Responses ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Selection For ◽  
Color Score ◽  
Daily Gain

Means, heritabilities, genetic and phenotypic correlations, and correlated responses in carcass traits (total carcass backfat, carcass length, area 1. dorsi, ham weight, percentage ham of side, percentage lean in ham face, color score, texture score, and marbling score) during 11 generations of selection for postweaning average daily gain were studied on a selected Lacombe line, a Yorkshire control line, and a crossbred Lacombe × Yorkshire group generated each year from the two lines. With the exception of color score, the heritability estimates were moderate to high. Genetic and phenotypic correlations between average daily gain and the carcass traits ranged from − 0.16 to 0.46 and from − 0.07 to 0.15, respectively. Correlated responses in the carcass traits were very small. Key words: Swine, carcass traits, selection, heritabilities, correlations

Selection for components of efficient lean growth rate in pigs 2. Selection pressure applied and direct responses in a Landrace herd

1994 ◽  
Vol 59 (2) ◽  
pp. 263-269 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran
Keyword(s):  
Growth Rate ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Direct Response ◽  
Lean Growth ◽  
Ad Libitum ◽  
Selection For ◽  
Ad Libitum Feeding

AbstractResponses to divergent selection for lean growth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Landrace pigs were studied. Selection was practised for four generations with a generation interval ofl year. A total of 2642 pigs were performance tested in the high, low and control lines, with an average of 37 boars and 39 gilts performance tested per selection line in each generation. The average within-line inbreeding coefficient at generation four was equal to 0·04. There was one control line for the DFI and LFC selection groups and another control line for the LGA selection group. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively with ad-libitum feeding. The selection criteria had phenotypic s.d. of 32, 29 and 274 units, for LGA, LFC and DFI, respectively, and results are presented in phenotypic s.d.Cumulative selection differentials (CSD) were 5·1, 4·5 and 5·5 phenotypic s.d. for LGA, LFC and DFI, respectively. Direct responses to selection were 1·4,1·1 and 0·9 (s.e. 0·20) for LGA, LFC and DFI. In each of the three selection groups, the CSD and direct responses to selection were symmetric about the control lines. The correlated response in LFC (1·1, s.e. 0·19) with selection on LGA was equal to the direct response in LFC. In contrast, the direct response in LGA was greater than the correlated response (0·7, s.e. 0·18) with selection on LFC. There was a negative correlated response in DFI (-0·6, s.e. 0·18) with selection on LFC, but the response with selection on LGA was not significant (0·2, s.e. 0·16).Heritabilities for LGA, LFC and DFI ivere 0·25, 0·25 and 0·18 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·12 (s.e. 0·02). Genetic correlations for LFC with LGA and DFI were respectively positive (0·87, s.e. 0·02) and negative (-0·36, s.e. 0·09), while the genetic correlation between DFI and LGA was not statistically different from zero, 0·13 (s.e. 0·10). Selection on components of efficient lean growth has identified LGA as an effective selection objective for improving both LGA and LFC, without a reduction in DFI.

Selection for lean growth rate and correlated responses in litter traits in a synthetic line of Yorkshire-Meishan pigs

2001 ◽  
Vol 81 (2) ◽  
pp. 205-214 ◽  
Author(s):  
P. Chen ◽  
T. J. Baas ◽  
J. C. M. Dekkers ◽  
L. L. Christian
Keyword(s):  
Growth Rate ◽  
Regression Coefficients ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Correlated Responses ◽  
Lean Growth ◽  
Litter Traits ◽  
Selection For ◽  
Synthetic Line

Selection for lean growth rate (LGR) was conducted for four generations in a synthetic line of Yorkshire-Meishan pigs to study the effectiveness of selection for LGR and correlated responses in litter traits. Lean growth rate was estimated from ultrasound measurements of 10th-rib backfat thickness and longissimus muscle area. In the selection line, 7 boars and 20 gilts with the highest LGR were selected to produce the next generation. The generation interval was 13 mo and the average selection differential per generation was 1.1 phenotypic standard deviation units. A contemporaneous control line was maintained by randomly selecting 5 boars and 15 gilts. Data from a total of 1057 pigs sired by 58 boars and out of 133 sows were available from the two lines. Selection responses were estimated from deviations of the selection line from the control line using least squares (LS) and by multiple trait derivative-free restricted maximum likelihood analysis using an animal model (AM). The estimate of response to selection per generation using LS was 9.4 ± 0.95 g d–1 for LGR. The corresponding estimate from the AM was 9.8 ± 0.51 g d–1. Correlated responses in litter traits were regressed on generation. For the LS method, regression coefficients were negative but not significant (P > 0.05) for total number born, number born alive, and number at 21 d and at 42 d. Significant, positive correlated responses occurred in 42-d litter weight and 21-d piglet weight (P < 0.05). For the AM method, the regression coefficients were also negative, but were not significant (P > 0.05) for numberalive at birth, at 21 d, and at 42 d. A significant positive correlated response occurred only for 42-d litter weight (P < 0.05). Although results are based on a population of limited size, it can be concluded that selection for LGR in a synthetic line is effective and should have little effect on litter traits. Key words: Pigs, selection, lean growth rate, correlated response

Corn or soybean hull incorporation into haylage-based backgrounding beef cattle diets: Effect on growth and efficiency during the backgrounding and finishing periods

2007 ◽  
Vol 87 (4) ◽  
pp. 615-621 ◽  
Author(s):  
K. C. Swanson ◽  
M. Ko ◽  
C. J. Mader
Keyword(s):  
Body Weight ◽  
Beef Cattle ◽  
Dry Matter ◽  
Average Daily Gain ◽  
Soybean Hulls ◽  
Feedlot Performance ◽  
Final Body Weight ◽  
Plasma Urea ◽  
Soybean Hull ◽  
Daily Gain

This experiment was conducted to evaluate the effects of corn or soybean hull incorporation into haylage-based diets on backgrounding calf performance and subsequent feedlot performance. Crossbred steers [n = 48, initial body weight (BW) = 303 ± 3.4 kg] were individually fed dietary treatments consisting of: (1) haylage [17.5% crude protein, dry matter (DM) basis; control], (2) haylage + 20% (DM basis) cracked corn, and (3) haylage + 20% (DM basis) soybean hulls during a 112-d backgrounding period. After the backgrounding period, all steers were adapted to a common high moisture corn-based finishing diet and fed until an ultrasound estimated backfat thickness of 7 mm was obtained. During the backgrounding period, steers fed cracked corn or soybean hulls had greater (P < 0.01) average daily gain, dry matter intake and gain:feed and lower (P = 0.05) plasma urea N as compared with controls. However, when finished on a common high-concentrate diet, steers previously fed cracked corn had greater (P < 0.08) average daily gain, final body weight, and longissimus muscle area than those fed soybean hulls, suggesting that source of supplemental energy during the backgrounding period may influence subsequent feedlot performance. Key words: Beef cattle, backgrounding, energy supplementation

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.

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