Direct and correlated responses to selection for weaning weight, post-weaning weight gain and six-week weight in mice

1984 ◽  
Vol 67 (2-3) ◽  
pp. 113-122 ◽  
Author(s):  
R. L. Baker ◽  
E. H. Cox ◽  
A. H. Carter
Keyword(s):  
Weight Gain ◽  
Correlated Responses ◽  
Weaning Weight ◽  
Selection For

Divergent breeding values for fatness or residual feed intake in Angus cattle. 5. Cow genotype affects feed efficiency and maternal productivity

2018 ◽  
Vol 58 (1) ◽  
pp. 80 ◽  
Author(s):  
M. L. Hebart ◽  
J. M. Accioly ◽  
K. J. Copping ◽  
M. P. B. Deland ◽  
R. M. Herd ◽  
...  
Keyword(s):  
Weight Gain ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Residual Feed Intake ◽  
Bodyweight Gain ◽  
High Fat ◽  
Low Fat ◽  
Weaning Weight ◽  
Angus Cattle ◽  
Selection For

Cow bodyweight gain, calf weaning weight, feed intake and maternal productivity of 500 Angus cows, in 64 replicate groups, were measured over three parities at two locations (Struan and Vasse) as part of the Beef CRC Maternal Productivity Project. The cows were sourced as heifers from the top and bottom 10% of BREEDPLAN Rib Fat EBV (High-Fat and Low-Fat), and from High and Low residual feed intake (RFI) selection lines (High-RFI and Low-RFI). Each of the four genotypes were run under High- and Low-Nutrition (measured as feed on offer) at both sites. The High-Fat cows were 7% more efficient at producing weaner calves under Low-Nutrition than were the Low-Fat cows. This was driven primarily by the 4% difference between the lines in weaning rate. When weaning rate differences were accounted for (as covariate), there was no difference between the Fat lines in the efficiency of weaner weight production. When the weight gain of the cow was included as an output in addition to calf weaning weight, there was also no difference between the Fat lines in efficiency. Low-RFI cows were always more efficient at producing weaner calves than were the High-RFI cows. This was primarily driven through a 7% reduction in annual feed intake (across both nutrition treatments). However, the Low-RFI cows were leaner, had 6.3% lower weaning rate and calved on average 5.4 days later than did the High-RFI cows. Furthermore, the largest differences in feed intake were in spring when feed availability is greatest. In the context of the results herein, a balanced breeding program should include selection for improved reproduction and low RFI.

RESPONSE TO SELECTION FOR WEIGHT-PER-DAY-OF-AGE IN RAMBOUILLET AND ROMNELET SHEEP

1975 ◽  
Vol 55 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J. A. VESELY ◽  
H. F. PETERS
Keyword(s):  
Genetic Correlations ◽  
Response To Selection ◽  
Correlated Responses ◽  
Weaning Weight ◽  
Two Generations ◽  
Selection For ◽  
Heritability Estimates

Responses to selection for weight-per-day-of-age (WPDA) to about 170 days in Rambouillet and Romnelet sheep over 5 yr, comprising two generations, were measured by two methods. Correlated responses in weaning weight (WW) at about 100 days, and postweaning gain (PWG) for 70 days were also estimated. The estimates of annual genetic increases in WPDA were quite similar in both breeds and from both methods. The improvements of this trait in Rambouillet and Romnelet were estimated as 9.7 and 6.0 g/yr from method 1, and 9.1 and 7.8 g/yr from method II. Estimates of correlated responses in PWG obtained by both methods and in both breeds were close to expected estimates, but correlated responses in WW appeared to be overestimated. Heritability estimates for WPDA using paternal half-sibs were 0.20 for Rambouillet and 0.18 for Romnelet. All genetic correlations among the three traits were positive. Realized heritabilities for WPDA were 0.28 and 0.20 in Rambouillet and Romnelet by method I, and 0.26 in both breeds by method II.

scholarly journals Genetic parameters and response to selection for post-weaning weight gain, visual scores and carcass traits in Hereford and Hereford×Nellore cattle

2011 ◽  
Vol 137 (1-3) ◽  
pp. 231-237 ◽  
Author(s):  
Fábio Luiz Buranelo Toral ◽  
Vanerlei Mozaquatro Roso ◽  
Cláudio Vieira de Araújo ◽  
João Cruz Reis Filho
Keyword(s):  
Weight Gain ◽  
Genetic Parameters ◽  
Carcass Traits ◽  
Response To Selection ◽  
Weaning Weight ◽  
Nellore Cattle ◽  
Selection For

scholarly journals CORRELATED RESPONSES IN WEIGHTS OF IMPROVED INDIGENOUS PIGS - NIGERHYB - IN NIGERIA

2021 ◽  
Vol 22 (2) ◽  
pp. 113-119
Author(s):  
O. A. Adebambo
Keyword(s):  
Weight Gain ◽  
Birth Weight ◽  
Genetic Correlations ◽  
Correlated Responses ◽  
Good Criterion ◽  
Phenotypic Correlations ◽  
Selection For ◽  
Heritability Estimates ◽  
Indigenous Pigs

Data collected on the weight of 1681 offsprings of improved indigenous pigs from 1984 to 1990 were used to obtain heritability estimates; genetic, environmental and phenotypic correlations among weights and gains from birth to mature and yearling weights. The estimates were used to predict expected change from correlated responses from single trait selection. Heritability estimates obtained from paternal half-sib analysis were birth weight 0.90 ±0. 08; gain from birth to weaning 0.14±0.11; 150 days weight 0.49±18; gain from weaning to 150 days 0.49±0.15; weight gain from.150 days to yearling weight 0.41 ± 026 and yearling weight 0.66±. Genetic correlations among all weights and gains were fairly high, ranging from 0.25 to 0.81. Selection for individual pig weight at 56 days appear to be a single good criterion for selection for growth at other ages with coheritabilities of 0.669 for 56 and 150 days weight and 0,856 for 56 days versus yearling weight.

Consequences of selection for weaning weight in zebu, Bos taurus and zebu × Bos taurus cattle in the tropics

1991 ◽  
Vol 42 (2) ◽  
pp. 295 ◽  
Author(s):  
HM Burrow ◽  
HM Burrow ◽  
GW Seifert ◽  
GW Seifert ◽  
DJS Hetzel ◽  
...  
Keyword(s):  
Birth Weight ◽  
Bos Taurus ◽  
Realized Heritability ◽  
Crossbred Cattle ◽  
Correlated Responses ◽  
Weaning Weight ◽  
Resistant Genotype ◽  
Selection For ◽  
Susceptible Populations ◽  
The Tropics

Direct and correlated responses to a single generation of divergent selection for weaning weight per day of age (WA/A) were examined in Bos taurus, zebu and zebu crossbred cattle in a tropical environment. Selection for high WW/A resulted in increased liveweights at all ages in all genotypes, with the exception of birth weight in the Bos taurus genotype. Preweaning daily gains were higher in all genotypes selected for high WW/A, but postweaning daily gains did not differ in two zebu crossbred genotypes. Overall parasite and heat resistance did not change significantly as a result of selection. However, selection within the more resistant genotype/sex populations resulted in higher tick and worm burdens, while in the more susceptible populations tick and worm loads decreased. An examination of lifetime cow fertility showed that cows with high preweaning growth reared more calves to weaning (P < 0.05), had fewer neonatal mortalities (P < 0.10) and also calved earlier (P < 0.01) than cows with low preweaning growth, leading to the conclusion that cows with high WW/A have improved lifetime fertility. Heritability of birth weight, WW/A and 18 month weight per day of age over all genotypes was estimated by parent-offspring regression to be 0.46, 0.21 and 0.22 for each of the traits respectively. The realized heritability of WW/A was 0.17 over all genotypes.

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