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.

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.

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

INFLUENCE OF BODY WEIGHT AND CHANGES IN BODY WEIGHT OF THE COW ON PREWEANING TRAITS OF THE CALF

1980 ◽  
Vol 60 (3) ◽  
pp. 599-607
Author(s):  
G. W. RAHNEFELD ◽  
R. J. PARKER ◽  
S. YODSERANEE ◽  
E. W. STRINGAM
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Average Daily Gain ◽  
Control Line ◽  
Selection Experiment ◽  
Weight Changes ◽  
Apparent Effect ◽  
Weaning Weight ◽  
Factors Affecting ◽  
Daily Gain

This study was designed to estimate and evaluate environmental factors affecting birth weight, weaning weight and preweaning average daily gain (ADG) of purebred Shorthorn calves from the control line of a selection experiment. Nine years of data consisted of 635 birth weight and 607 weaning weight records. Least squares analysis of variance revealed that sex of the calf was the most important source of variation: males averages 2.31 kg heavier at birth, were 14.3 kg heavier at weaning and gained 0.08 kg more per day from birth to weaning than females. Heavier cows in June, October, and December prior to parturition and at parturition produced heavier calves at birth. Heavier cows in October prior to parturition, at parturition, and in June or October following parturition produced calves which grew more rapidly from birth to weaning and were heavier at weaning. There was no apparent effect of cow weight changes before or after parturition on preweaning traits. Correlations of birth weight with weaning weight, preweaning ADG and cow weight at parturition were 0.56 ± 0.03, 0.43 ± 0.04 and 0.24 ± 0.04 respectively. Correlations of weaning weight and preweaning average daily gain with cow weights at parturition were 0.42 ± 0.04 and 0.40 ± 0.04. Correlations among cow weights in June, October, and December prior to parturition, at parturition, and in June and October following parturition were estimated.

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

scholarly journals PSVII-9 Evaluating Performance Trends of the Four Most Represented Breeds of Bulls in the Utah Beef Improvement Performance Test

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 304-304
Author(s):  
Matthew D Garcia ◽  
Madelyn Kunzler ◽  
Kim Chapman
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
Rate Of Change ◽  
Test Weight ◽  
Initial Test ◽  
Final Test ◽  
Weaning Weight ◽  
Increasing Trend ◽  
Red Angus ◽  
Daily Gain

Abstract This study evaluated changes in performance of bulls enrolled in the Utah Beef Improvement Association’s (UBIA) annual performance tests conducted in accordance with central bull test standards established by the Beef Improvement Federation. Breeds with over 500 bulls enrolled over the period of 2004 to 2018 were included in the evaluation. The breeds with greater than 500 animals evaluated included the Angus, Red Angus, Hereford and Simmental Breeds. Traits evaluated included birth weight, initial weight, a 205-day adjusted weaning weight, final test weight, average daily gain, adjusted yearling weight, and weight per day of age. The mixed model procedure of SAS and interval regression analyses were utilized to evaluate the yearly rate of change for each breed and to determine if that rate of change was significantly different (P < 0.05) between the evaluated breeds. When evaluating all breeds represented across years, significant differences (P < 0.05) were observed for rate of change when evaluating birth weight and 205-day adjusted weaning weight. However, no differences were observed between breeds with more than 500 animals represented. Significant differences (P < 0.05) for rate of change were observed when comparing the top four represented breeds, for average daily gain, initial test weight, final test weight, adjusted yearling weight and weight per day of age. Specifically, a declining trend was noted for all breeds when evaluation all significant traits. When evaluating the previously described traits, the Angus breed was significantly different in its rate of decline when compared to the Red Angus and Hereford breeds. The lone increasing trend was observed in the Hereford breed which had a positive increasing trend for initial test weight which was significantly different (P < 0.05) from both the Angus and Red Angus breeds but not significantly different from the Simmental breed.

Genetic improvement of meat sheep. 1. A comparison of different methods of correcting weaning weight for age of lamb

1976 ◽  
Vol 16 (80) ◽  
pp. 325 ◽  
Author(s):  
IP Gregory ◽  
EM Roberts ◽  
JW James
Keyword(s):  
Birth Weight ◽  
Genetic Improvement ◽  
Average Daily Gain ◽  
Weaning Weight ◽  
Significant Difference ◽  
Meat Sheep ◽  
Daily Gain ◽  
Weight For Age

Several methods of correcting lamb weaning weight for age were compared. Lambs were weighed at birth, at 90 � 1 day of age, when the oldest and when the youngest lamb was 90 days and when the average age of lambs was 90 days. Weights were adjusted to 90 days by the methods of regression, regression pooled within sire groups, average daily gain with and without a standard birth weight and weight per day of age. All the correction methods examined gave similar results and there was no significant difference between methods. The correlations between the actual 90-day weight and the adjusted weights ranged from 0.922 to 0.960 and were highest when the weights taken when the average age of lambs was 90 days were used as the basis for adjustment. All adjusted weights were significantly biased as estimates of actual 90-day weight, but the bias was least for weights when average age was 90 days.

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.

AGE AND WEIGHT AT PUBERTY OF CROSSBRED HEIFERS SIRED BY CHAROLAIS, LIMOUSIN, AND SIMMENTAL BULLS

1977 ◽  
Vol 57 (4) ◽  
pp. 697-703 ◽  
Author(s):  
E. E. SWIERSTRA ◽  
G. W. RAHNEFELD ◽  
R. L. CLIPLEF ◽  
J. H. STRAIN
Keyword(s):  
Birth Weight ◽  
Growth Rates ◽  
Average Daily Gain ◽  
Weaning Weight ◽  
Calving Season ◽  
Daily Gain ◽  
Visual Observations

Age and weight at first observed estrus (puberty) were studied in 471 crossbred heifers produced by inseminating Angus, Hereford, and Shorthorn cows with semen from Charolais, Limousin, and Simmental bulls. Heifers were kept in drylots after weaning and gained an average of 0.68 kg/day. Visual observations and vasectomized bulls fitted with marking harnesses were used for estrous detection. At puberty, the median and mean ages were 336 and 342 days, and the median and mean weights 296 and 305 kg. At puberty, Charolais- and Simmental-sired heifers were about 22 days younger (median age; P < 0.01) than Limousin-sired heifers (324 and 326 vs. 347 days, respectively). Charolais-sired heifers were significantly heavier (median weight) than Limousin- and Simmental-sired heifers (306 vs. 294 and 292 kg, respectively). Heifers from Angus and Hereford dams were about 22 days older (P < 0.01) at puberty than heifers from Shorthorn dams (median 347 and 346 vs. 324 days). Heifers with high preweaning growth rates attained puberty at an earlier age (r = −0.24; P < 0.01). Day of birth within the year had a significant effect on age and weight at puberty; i.e., heifers born early in the calving season were older and heavier at puberty. Weight at puberty was associated with weaning weight (r = 0.61; P < 0.01), birth weight (r = 0.41; P < 0.01), and preweaning average daily gain (r = 0.54; P < 0.01). Calves that were heavy at birth tended to be heavy at weaning, and heavy weaning weights, in turn, were associated with heavy weights at puberty. By 15 mo of age, 99% of all heifers were cycling.

Performance of Hereford and crossbred Hereford cattle in the subtropics of New South Wales: genetic analyses of pre-weaning performance of first-cross calves

1980 ◽  
Vol 31 (2) ◽  
pp. 417 ◽  
Author(s):  
R Barlow ◽  
GH O'Neill
Keyword(s):  
Birth Weight ◽  
Genetic Correlations ◽  
Environmental Variation ◽  
Direct Selection ◽  
Gestation Length ◽  
Strongly Correlated ◽  
Weaning Weight ◽  
Selection For ◽  
Sire Breed ◽  
Size At Birth

First-cross calves of Simmental (S), Friesian (F), and Brahman (B) sires were compared with straight-bred calves of Hereford (H) sires over 5 years at Grafton, N.S.W. There was a total of 775 calves sired by 205 bulls with complete records of performance from conception to weaning. Analyses were conducted to determine sire breed and sire breed x environment effects, and to provide paternal half-sib estimates of heritabilities and genetic and phenotypic correlations. Various models were used to ascertain the sensitivity of genetic parameters to the removal of different sources of variation. Among females, S x H were heaviest at birth, while among males, B x H were heaviest. The regression coefficient of birth weight on gestation length was significantly greater for B x H calves than for other crosses. All crosses grew significantly faster to weaning and were significantly heavier at weaning than H x H calves. However, there were a number of significant interactions between sire breed and environmental variables for measures of pre-weaning growth. S x H and F x H calves appeared most sensitive to environmental variation, while B x H appeared least sensitive. The significance of this is discussed. Estimates of heritability for most traits were high. Values derived by using simple models were: gestation length, 0.68; birth weight, 0.56; average daily gain (ADG) to weaning, 0.47; weaning weight, 0.54; eyelid pigmentation, 0.50. Heritabilities of birth weight and ADG during the early pre-weaning period appeared most sensitive to the amount of environmental variation removed in the model. Gestation length was positively correlated with size at birth but negatively correlated with growth to weaning. There were large positive genetic correlations among various measures of size at birth, and among various measures of growth to weaning. When compared with ADG to weaning, weaning weight was more strongly correlated with birth weight, but less strongly correlated with gestation length. The results also indicated that selection for gain over a fixed time period, immediately prior to weaning, would be as efficient as direct selection for total ADG to weaning.

THE EFFECT OF INBREEDING ON PREWEANING GROWTH OF YANKASA SHEEP

2021 ◽  
Vol 26 ◽  
pp. 6-10
Author(s):  
E. M. Awemu ◽  
B. Y. Abubakar ◽  
L. N. Nwakalor
Keyword(s):  
Birth Weight ◽  
Growth Traits ◽  
Average Daily Gain ◽  
Regression Coefficients ◽  
Breeding Period ◽  
Weaning Weight ◽  
Inbreeding Coefficients ◽  
Using Data ◽  
Inbreeding Level ◽  
Daily Gain

The accumulated and annual levels of inbreeding and their effects on growth traits of lambs were investigated using data collected over 11 years at the National Animal Production Research Institute Zaria. Inbreeding level averaged 1.313% per year, cumulating to 14.45% over the years. Average individuals inbreeding coefficients of offspring from sires used for more than one breeding period was 0.103% across the inbred individuals and 0.004% over all lambs. Regression coefficients of growth traits (everage values per year) on inbreeding levels by year were – 0.185kg ± 1.820g and -0.391kg for birth weight, preweaning average daily gain and weaning weight, respectively. All regression coefficients indicated that birth weight and weaning weight declined by 0.185kg and 0.391kg, respectively while preweaning average daily gain increased by 1.820g. Conscious efforts to reduce inbreeding level and its effects on growth traits will greatly lead to improved productivity

Sign in / Sign up

Export Citation Format

Share Document