scholarly journals Genetic Variation in Body Weight and Egg Production in an Experimental Line Selected Long Term for Increased Egg Production, a Commercial Dam Line, and Reciprocal Crosses Between Lines

2004 ◽  
Vol 83 (7) ◽  
pp. 1055-1059 ◽  
Author(s):  
K.E. Nestor ◽  
J.W. Anderson ◽  
R.A. Patterson ◽  
S.G. Velleman
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Egg Production ◽  
Reciprocal Crosses ◽  
Experimental Line

Effect of long term selection for juvenile body weight and egg production on semen quality in broiler breeder dam line

2017 ◽  
Vol 52 (2) ◽  
pp. 222
Author(s):  
M. Shanmugam ◽  
M. Niranjan ◽  
K. Rakesh ◽  
T.K. Bhattacharya ◽  
B.L.N. Reddy ◽  
...  
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Semen Quality ◽  
Broiler Breeder ◽  
Term Selection ◽  
Selection For

Physiological genetics of dietary restriction: uncoupling the body temperature and body weight responses

2007 ◽  
Vol 293 (4) ◽  
pp. R1522-R1527 ◽  
Author(s):  
Brad A. Rikke ◽  
Thomas E. Johnson
Keyword(s):  
Body Weight ◽  
Genetic Variation ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Dietary Restriction ◽  
The Body ◽  
Strain Variation ◽  
Long Term Effects ◽  
Difficult Challenge

Numerous physiological and molecular changes accompany dietary restriction (DR), which has been a major impediment to elucidating the causal basis underlying DR's many health benefits. Two major metabolic responses to DR that potentially underlie many of these changes are the body temperature ( Tb) and body weight (BW) responses. These responses also represent an especially difficult challenge to uncouple during DR. We demonstrate in this study, using two recombinant inbred (RI) panels of mice (the LXS and LSXSS) that naturally occurring genetic variation serves as a powerful tool for modulating Tb and BW independently during DR. The correlation coefficient between the two responses was essentially zero, with R = −0.04 in the LXS and −0.03 in the LSXSS, the latter averaged across replicate cohorts. This study is also the first to report that there is highly significant ( P = 10−10) strain variation in the Tb response to DR in the LXS (51 strains tested), with strain means ranging from 2 to 4°C below normal. The results suggest that the strain variation in the Tb response to DR is largely due to differences in the rate of heat loss rather than heat production (i.e., metabolic rate). This variation can thus be used to assess the long-term effects of lower Tb independent of BW or metabolic rate, as well as independent of food intake and motor activity as previously shown. These results also suggest that murine genetic variation may be useful for uncoupling many more responses to DR.

scholarly journals Estimation of Additive and Non-Additive Genetic Variances of Body Weight, Egg Weight and Egg Production for Quails (Coturnix coturnix japonica) with an Animal Model Analysis

2006 ◽  
Vol 49 (3) ◽  
pp. 300-307 ◽  
Author(s):  
N. Mielenz ◽  
R. R. Noor ◽  
L. Schüler
Keyword(s):  
Animal Model ◽  
Body Weight ◽  
Egg Production ◽  
Additive Model ◽  
The Body ◽  
Phenotypic Variance ◽  
Egg Weight ◽  
Term Selection ◽  
Inbreeding Coefficients

Abstract. This study estimates the additive and non-additive variances for egg production and body weight traits of two lines of quails from a long-term selection with the help of the REML method. For the body weight of 42-day-old females (BW42f) and males (BW42m), a total of 7,934 records for line 1 and 7,214 records for line 2 from 21 generations were used in our analyses. Additionally, 1,717 records of females from line 1 and 1,671 records of females from line 2 contained information on their egg production at an age of 42 to 200 days (EN200), on the average egg weight for the first 11 weeks of their laying season (EW1), on the average egg weight from weeks 12 to 23 (EW2), and on their body weight at an age of 200 days (BW200f). A multivariate additive animal model and one-trait dominance models, which include the inbreeding coefficients as covariates, were fitted to the data. The estimates of the heritability gained from our dominance models were smaller than those from the additive model. For line 1, the heritability values decreased for EN200 from 0.35 to 0.32, for EW1 from 0.66 to 0.56, for BW200f from 0.42 to 0.38, and for BW200m from 0.51 to 0.49, respectively. For the first line, the respective ratio (d2) of the dominance variance to the phenotypic variance for EN200, EW1, BW200f and BW200m was 0.08, 0.22, 0.09 and 0.21, and the values for the second line were 0.12, 0.06, 0.001 and 0.23.

scholarly journals Direct and Correlated Responses to Long-Term Selection for Increased Body Weight and Egg Production in Turkeys

1996 ◽  
Vol 75 (10) ◽  
pp. 1180-1191 ◽  
Author(s):  
KARL E. NESTOR ◽  
D.O. NOBLE ◽  
J. ZHU ◽  
Y. MORITSU
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Correlated Responses ◽  
Term Selection ◽  
Selection For

THE LONG-TERM EFFECTS OF FEEDING GROUND AND WHOLE COTTONSEED TO LAYING HENS

1989 ◽  
Vol 69 (2) ◽  
pp. 425-431 ◽  
Author(s):  
R. C. FITZSIMMONS ◽  
MARK NEWCOMBE ◽  
I. E. MOUL
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Egg Production ◽  
Laying Hens ◽  
Egg Yolk ◽  
Long Term Effects ◽  
Commercial Diet ◽  
Voluntary Feed Intake ◽  
Whole Cottonseed

Laying hens were fed diets containing 0, 2.5, 5, 10, 15 and 20% whole or ground cottonseed. Birds fed the 15 and 20% ground cottonseed diets rapidly reduced voluntary feed intake and, as a result, suffered a loss in both body weight and egg production. The severity of the dietary effects of cottonseed on productivity and mottled yolks was positively correlated with the level of cottonseed and gossypol in the diet. Egg yolk discoloration was assessed both visually on fresh yolks and using a time exposure to ammonia fumes. Discoloration was easier to detect using the ammonia test. In all cases, egg yolk discoloration was no longer apparent after a maximum of 42 d of feeding a commercial diet. Key words: Cottonseed, gossypol, laying hen, yolk mottling, egg production, feed intake

Single crossing between White Leghorn and Australorp

1958 ◽  
Vol 9 (6) ◽  
pp. 842 ◽  
Author(s):  
JA Morris ◽  
F Skaller
Keyword(s):  
Body Weight ◽  
Artificial Insemination ◽  
Sexual Maturity ◽  
Egg Production ◽  
The Body ◽  
White Leghorn ◽  
Reciprocal Crosses ◽  
Related Data ◽  
Single Crossing ◽  
White Leghorns

Egg production and related data are presented for 1520 pullets resulting from nine generations of single crossing between White Leghorns and Australorps. Both types of reciprocal crosses were consistently superior to the better of the parental breeds (White Leghorn) in hatchability, chick viability, and egg production. This superiority became still more apparent when pure and crossbred half-sisters were compared. Crossbreeding was not effective in improving the viability of adult birds or the body weight, the latter remaining intermediate between that of the two pure breeds. The number of days required to reach sexual maturity was decreased as a result of crossbreeding. The crossbreds showed less variation in egg production and included in their sample a much smaller percentage of extremely low-producing pullets. A comparison between the two types of crossbreds shoved differences in individual years, but when viewed over the whole period of the experiment the only consistent differences were the superior hatchability and higher fertility, under artificial insemination conditions, when the White Leghorn served as the dam. There were no significant differences in production characters between the two types of crossbreds when housed on deep litter.

scholarly journals A comparison of the interaction, with two types of environment, of pure strains or strain crosses of poultry

1963 ◽  
Vol 4 (3) ◽  
pp. 370-381 ◽  
Author(s):  
P. Hull ◽  
R. S. Gowe ◽  
S. B. Slen ◽  
R. D. Crawford
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Environmental Effect ◽  
Egg Production ◽  
Genetic Variance ◽  
Environment Interaction ◽  
Reciprocal Crosses ◽  
Genotype Environment Interaction ◽  
Six Traits ◽  
Interaction Variance

In these experiments comparisons were made between the magnitude of the interaction of ‘pure’ strains and strain crosses of poultry with two types of environments—location effects and a restricted-feed versus a full-feed rearing programme. The ‘pure’ strains were closed flocks of White Leghorns that had been selected for increased egg production, while the strain crosses were the reciprocal crosses of all combinations of these pure strains. Data from four separate experiments in four consecutive years used for this study involved 8320 laying birds. Six traits of the adult laying birds were used for these analyses.It was expected that the ‘pure’ strains would differ in performance amongst themselves to a greater extent than the strain crosses, and for the two traits, body-weight at housing and sexual maturity, this was found to be the case in three out of four years. These two traits were affected to the greatest extent by the rearing treatment. Also, the genotype-environment interaction variance was found to be significant and of important magnitude relative to the genetic variance for these two traits. Where the environmental effect was found to be smaller, the interaction variance made up a smaller proportion of the genetic variance.

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