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.

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. 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.

scholarly journals PSIII-5 Effects of ingredient composition of oral drenches in small piglets post-farrowing on average daily gain and pre-wean mortality

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 238-238
Author(s):  
Olivia Harrison ◽  
Samantha Tauer ◽  
Brent Frederick
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
High Energy ◽  
Experimental Unit ◽  
Swine Industry ◽  
Bioactive Proteins ◽  
Randomized Design ◽  
Significant Difference ◽  
Key Factor ◽  
Daily Gain

Abstract Number of pigs born alive has been a key factor of the increasing efficiency of the U.S. swine industry. However, with increased pigs in the uterus, birth weight has been negatively impacted, with more small or at-risk pigs being born per litter. In order to overcome these changes, a study testing three commercial oral drenches against a control to determine which would increase average daily gain and decrease preweaning mortality. In a completely randomized design, 877 one-day-old suckling pigs from a high-health farm were selected for the experiment if they appeared to be in the bottom 20% of bodyweight compared to their contemporaries. Selected pigs were given one of four drenching treatments: 1) none (control), 2) bioactive proteins (BP), 3) high energy sugars (HES), and 4) immunoglobulins (IgY). Pigs were weighed on d 1 and d 19 of age (weaning), with mortality tracked during the suckling period. Data were analyzed using SAS v 9.4 (Cary, NC), with pig as the experimental unit and an accepted alpha of 0.05. Treatment had no detected effect on birth weight, weaning weight, ADG, or mortality (P = 0.79, 0.96, 0.86, 0.38 respectively). Likewise, statistical contrasts were used to determine there was no detected impact (P > 0.10) of drench, regardless of type, compared to the control in any measured response criteria. Interesting, pigs drenched with BP or IgY had numerically lower preweaning mortality (11.2 and 11.5% respectively), than those administered the control or HES (15.4 and 15.2%, respectively). In conclusion, this experiment showed no significant difference in the performance between piglets given no product vs. those drenched with bioactive proteins, high energy sugars, or immunoglobulins. However, additional research is warranted with greater replication or disease stressors to better understand if oral drenches may improve preweaning performance or mortality in different situations.

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.

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.

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

A note on the association between transferrin types and some productive traits in Iranian sheep

1976 ◽  
Vol 22 (1) ◽  
pp. 123-125 ◽  
Author(s):  
M. Pasdar ◽  
M. Makarechian ◽  
A. Farid
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
Significant Source ◽  
Weaning Weight ◽  
Productive Traits ◽  
Daily Gain

SummaryAn investigation was made of the association of transferrin types with birth weight, weaning weight and average daily gain from birth to weaning in three breeds of Iranian sheep. Transferrin type was not a significant source of variation in weight.

PRE- AND POST WEANING GROWTH OF CATTALO, HEREFORD, AND 1/4 BRAHMAN–3/4 HEREFORD CALVES

1976 ◽  
Vol 56 (3) ◽  
pp. 489-496
Author(s):  
J. E. LAWSON ◽  
D. G. KELLER
Keyword(s):  
Birth Weight ◽  
Average Daily Gain ◽  
Weaning Weight ◽  
Digestible Energy ◽  
Daily Gain

Hereford calves exceeded cattalo calves (averaging 1/7 bison–6/7 domestic and the product of matings of cattalo bulls of 1/14–3/16 bison to cattalo cows of 1/4–1/2 bison) by 3.8% in birth weight, based on data taken on 654 calves between 1958 and 1964. Hereford (72) and cattalo (164) calves born in 1961–1963 did not differ in average daily gain to weaning or in weaning weight, but Hereford calves exceeded cattalo calves by 15.5 and 4.7% in average daily gain in the feedlot and weight at the end of the 168-day feedlot test. In a comparison of calves born in 1962 and 1963, 32 1/4 Brahman–3/4 Hereford (1/4 Brahman calves were the result of backcrossing Hereford bulls to first-cross Brahman × Hereford cows), 110 cattalo, and 38 Hereford calves did not differ in birth weight; however, 1/4 Brahman calves showed evidence of the superior mothering ability of their dams by surpassing the cattalo by 19.2% and the Herefords by 24.3% in average daily gain to weaning, and excelling them by 17.9 and 14.0% in weaning weight. Hereford calves had 14.1 and 15.9% larger average daily gains in the feedlot and required only 86.6 and 73.2% as much digestible energy (Meal) per kilogram of gain as the cattalo and 1/4 Brahman calves. At the end of the 168-day feedlot test, 1/4 Brahman calves were 7.9% heavier than the cattalo but the 1/4 Brahman and Hereford calves did not differ statistically.

COMPARISONS OF CROSSBRED CALVES BY SOUTH DEVON, MAINE- ANJOU AND SIMMENTAL SIRES FOR SOME BEEF PRODUCTION TRAITS

1974 ◽  
Vol 54 (2) ◽  
pp. 197-203 ◽  
Author(s):  
J. A. NEWMAN ◽  
G. M. WEISS ◽  
B. SCHRADER
Keyword(s):  
Birth Weight ◽  
Significant Interaction ◽  
Statistical Significance ◽  
Average Daily Gain ◽  
Carcass Weight ◽  
Production Traits ◽  
Marbling Score ◽  
Weaning Weight ◽  
Slaughter Age ◽  
Daily Gain

Breed of sire comparisons are made amongst calves born to commercial Hereford cows and sired by bulls of the South Devon (SD, 10 bulls used), Maine-Anjou (MA, two bulls used) and Simmental (SIM, eight bulls used) breeds. Numbers of observations ranged from 239 bulls and 224 heifers for "ease of birth" to 98 bulls for carcass traits. The feedlot test period was 91 days and three feedlot treatments were imposed. Slaughter criteria were subjective and "breed-of-sire" differences in slaughter age and carcass weight were not statistically significant (P > 0.05). Differences amongst breed-of-sire means attained statistical significance for "birth weight" (MA > SIM > SD; P < 0.001), weaning weight of males (MA > SIM > SD; P < 0.001), "on-test" weight (MA > SIM > SD; P < 0.001), average daily gain on test (MA > SIM > SD; P < 0.001) average fat depth/100 kg carcass weight (SD > MA = SIM, P < 0.05), trimmed, de-boned, defatted primal cuts per day of age (MA > SIM > SD; P < 0.01), meat marbling score (SD more marbled than SIM more marbled than MA; P <.05). A significant interaction existed between breed of sire and feeding group for average daily gain on test (P < 0.01) and cutability (P < 0.025). Breed-of-sire differences did not attain statistical significance for weaning weight of female calves, loin area/100 kg carcass weight, cut-ability, or meat color score.

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