Genetic improvement of meat sheep. 2. Correction of weaning weight in Dorset and Border Leicester sheep

1977 ◽  
Vol 17 (84) ◽  
pp. 31 ◽  
Author(s):  
IP Gregory ◽  
EM Roberts ◽  
JW James
Keyword(s):  
Environmental Factors ◽  
Least Squares ◽  
Genetic Improvement ◽  
Average Daily Gain ◽  
Regression Method ◽  
Least Squares Estimation ◽  
Weaning Weight ◽  
Meat Sheep ◽  
Daily Gain

Data from 14635 Dorset and 1214 Border Leicester lambs from nine properties and five years were used to estimate the effects on weaning weight of age of lamb, sex, birth-rearing status and parity of dam, using three methods (average daily gain, pooled regression and least squares). Corrections for all effects varied greatly over properties and years, indicating that weaning weight cannot be satisfactorily adjusted for these environmental factors by the use of standard corrections. The correlations between estimated effects from the three methods were significant, and correlations between the three adjusted weaning weights exceeded 0.9 in most cases. All three methods accounted for similar fractions of variance in weaning weight, but average daily gain correction actually increased the variance on some occasions. Since least squares estimation is complicated, it is concluded that the pooled regression method is better suited to performance recording applications, especially if corrections are estimated within weaning groups, as they should be in view of their variability.

Genetic improvement of meat sheep. 3. Heritability of weaning weight of Dorset and Border Leicester sheep

1977 ◽  
Vol 17 (84) ◽  
pp. 38 ◽  
Author(s):  
IP Gregory ◽  
EM Roberts ◽  
JW James
Keyword(s):  
Least Squares ◽  
Genetic Improvement ◽  
Average Daily Gain ◽  
Weaning Weight ◽  
Significant Difference ◽  
Meat Sheep ◽  
Daily Gain

The heritability of weaning weight, uncorrected and corrected by three different methods has been estimated from several Dorset properties and one Border Leicester property. The estimates varied greatly over properties. The half-sib heritabilities of uncorrected weaning weight exceeded those of all corrected weights in all properties but one and the reason was found to be non-random use of sires over the joining period. The pooled half-sib heritabilities of uncorrected weaning weight and weaning weight corrected by average daily gain, pooled regression and least squares were 0.27, 0.11, 0.15 and 0.18 respectively for the Dorsets and the corresponding estimates for the Border Leicester were 0.46, 0.20, 0.15 and 0.16 respectively. In the Dorsets the pooled heritabilities calculated by dam-offspring regression were 0.04, 0.06, 0.09 and 0.10 for uncorrecred weaning weight and weaning weight corrected by average daily gain, pooled regression and least squares respectively. There was no significant difference between the heritabilities of weaning weight corrected by least squares or pooled regression but the heritability of weaning weight corrected by least squares significantly exceeded that of weaning weight corrected by average daily gain.

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.

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.

Factors affecting pre-weaning growth and weaning conformation of Angus cattle

1978 ◽  
Vol 29 (2) ◽  
pp. 359
Author(s):  
R Barlow ◽  
EB Dettmann ◽  
LG Williams
Keyword(s):  
Least Squares ◽  
New South ◽  
Average Daily Gain ◽  
Factors Affecting ◽  
Angus Cattle ◽  
South Wales ◽  
Weaning Age ◽  
Males And Females ◽  
Main Effects ◽  
Daily Gain

Weaning weight (ww) and conformation score (cs) records from Angus calves in five New South Wales herds were analysed by least-squares procedures to assess the nature and magnitude of variation. Herd, year, age of dam and sex were considered as main effects. Covariates included in the models were weaning age (WA) for ww and average daily gain (ADG), and both WA and ww for cs. Male calves (steers and bulls) were 16.6 kg heavier at weaning than female calves. Dams that were 5-8 years of age weaned calves that were 30.1 kg, 15.4 kg and 6.7 kg heavier than 2-, 3- and 4-year-old dams respectively. When ww was not included as a covariate in the model, age of dam effects on cs reflected those on ww, and there was little difference in cs between males and females. When adjusted for differences in ww, males had poorer cs than females, and calves from 3-year-old dams, and from dams over 8 years old, had poorer cs than those from dams of all other ages. Partial regressions of ww and ADG on WA, and of cs on ww, varied considerably between herd/year/sex subgroups.

Normal growth and development up to one year of age of Sudanese cattle with special reference to the influence of Sex and sire

1968 ◽  
Vol 70 (2) ◽  
pp. 117-121 ◽  
Author(s):  
A. H. Osman ◽  
Y. Rizgalla
Keyword(s):  
Growth And Development ◽  
Average Daily Gain ◽  
Normal Growth ◽  
Body Measurements ◽  
Weaning Weight ◽  
Body Weights ◽  
Weaning Age ◽  
Heritability Estimates ◽  
One Year ◽  
Daily Gain

SUMMARYThree years' data on a herd of Sudanese cattle were used to study the influence of sex and sire on their growth from birth to 1 year of age. The traits studied included body weights at birth, weaning and yearling ages, and body measurements at birth and weaning age. Analysis of variance indicated no significant sex by sire interactions. Male calves had significantly (P < 0.01) heavier birth, weaning and yearling weights and faster pre-weaning average daily gain than female calves. There were no statistically significant differences between sexes in post-weaning gain or body measurements. The sire effects were highly significant (P < 0.01) for birth and yearling weights and postweaning average daily gain, but not for weaning weight and pre-weaning average daily gain. Sire effects were also significant (P < 0.05) for height at withers and heart girth at birth and weaning age and for body length at weaning age. The heritability estimates of birth and yearling weights and post-weaning gain were relatively high, whereas the heritability estimates of weaning weight and pre-weaning gain were low.

Evaluation of Angus, Charolais and Hereford as terminal sire breeds on Hereford and first-cross cows. I. Growth of progeny

1995 ◽  
Vol 46 (6) ◽  
pp. 1231 ◽  
Author(s):  
H Hearnshaw ◽  
PF Arthur ◽  
D Johnston ◽  
PD Stephenson
Keyword(s):  
Average Daily Gain ◽  
Growth Potential ◽  
High Quality ◽  
Weaning Weight ◽  
Adequate Nutrition ◽  
Breed Differences ◽  
Medium Quality ◽  
Terminal Sire ◽  
Daily Gain ◽  
Sire Breed

Pre-weaning growth of 482 Angus, Charolais and Hereford sired progeny out of straightbred Hereford (H x H) , and first-cross Brahman x Hereford (B x H) , Simmental x Hereford (S x H) and Friesian x Hereford (F x H) dams was evaluated. The dams grazed either high, medium or low quality pasture (pre-weaning pasture system) at Grafton, NSW. Progeny of dams from high quality pre-weaning pasture were slaughtered at 281 days of age for the vealer market. The progeny of dams from medium and low quality pre-weaning pastures were evaluated for post-weaning growth on pasture, on commercial properties in temperate NSW. They were slaughtered for either the yearling domestic (both sexes) or heavy export steer markets. Average daily gain (ADG) for the entire pre-weaning period was greater (P < 0.05) for Charolais (845 g/day) than Angus (790 g/day) and Hereford (783 g/day) sired progeny. This resulted in a higher ( P < 0.05) weaning weight of Charolais sired progeny of dams on high or medium quality pre-weaning pasture. On low quality pasture, however, sire breed differences in weaning weight were not significant (P > 0.05). This indicates that adequate nutrition should be provided for Charolais sired progeny to express their higher growth potential. Post-weaning ADG of Charolais sired progeny was higher (P < 0.05) than that of Angus or Hereford sired progeny, resulting in 14 months liveweight (for yearling domestic cattle) of 370, 345 and 345 kg and 27 months liveweight (for heavy export steers) of 635, 585 and 569 kg for Charolais, Angus and Hereford sired progeny respectively. Progeny of B x H dams on medium or low quality pre-weaning pastures had the highest pre-weaning ADG and weaning weight, but the lowest post-weaning ADG. This resulted in 27 months liveweight of 558, 582, 628 and 616 kg for steer progeny from H x H, B x H, S x H and F x H dams respectively.

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.

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.

scholarly journals 167 Evaluation of an out-of-season breeding system for organic lamb production in missouri

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 173-174
Author(s):  
Tumen Wuliji ◽  
Amy Bax ◽  
Liga Wuri ◽  
Luke Wilbers ◽  
Christopher Boeckmann
Keyword(s):  
Body Condition Score ◽  
Average Daily Gain ◽  
Live Weight ◽  
Organic Production ◽  
Weaning Weight ◽  
Organic Farm ◽  
Food And Agriculture ◽  
Agriculture Industry ◽  
Daily Gain ◽  
Lambing Rate

Abstract Organic production is one of the fastest growing food and agriculture industry. The seasonality of lamb production affects lamb markets and prices, whereas, an out-of-season breeding and organic fall lamb production scheme may enhance product availability and competiveness. Six rams and 100 Katahdin ewes were selected for an out-of-season breeding during April and May of 2017 and 2018, for two production years. Ewes were synchronized for estrus using CIDR® device (EaziBreed™) (12 d) before breeding and fed ‘flushing’ feed for four weeks. Ewes were bred in mixed sire groups for two estrus cycles (35 d). Animals were rotationally grazed and maintained good body condition score (3.0) throughout the seasons at certified organic farm in Missouri. Mean live weight measured monthly from breeding to lambing were 57.8, 60.1, 62.1, 64.7, and 59.3 kg. Eighty nine ewes lambed in fall 2017 giving birth to 121 lambs (136% lambing rate) and eighty eight ewes lambed in 2018 giving birth to 126 lambs (143% lambing rate). Ninety seven percent of weaned lambs were maintained as an organic production status for marketing. Lamb birth weight, average daily gain weight, weaning weight, and 30 d post weaning weight, post weaning average daily gain weight were recorded for 2017 born lambs as 3.74±0.03 kg, 21.00±0.24 kg, 24.78±0.28 kg, 176±2 g/d respectively. Organic weaner lambs were sold for 5 to 15% higher price values (P &lt; 0.05) per unit than non-organic peer groups at a local livestock auction sale.

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