scholarly journals GENETIC CORRELATION BETWEEN GROWTH RATE AND LITTER SIZE IN MICE

Genetics ◽  
1966 ◽  
Vol 54 (6) ◽  
pp. 1423-1429 ◽  
Author(s):  
G W Rahnefeld ◽  
R E Comstock ◽  
Madho Singh ◽  
S R NaPuket
Keyword(s):  
Growth Rate ◽  
Genetic Correlation ◽  
Litter Size

GENETIC CORRELATION BETWEEN GROWTH RATE AND LITTER SIZE IN MICE

1962 ◽  
Vol 4 (3) ◽  
pp. 289-295 ◽  
Author(s):  
G. W. Rahnefeld ◽  
W. J. Boylan ◽  
R. E. Comstock
Keyword(s):  
Growth Rate ◽  
Genetic Correlation ◽  
Litter Size

HERITABILITY AND GENETIC CORRELATION ESTIMATES IN A NEW BREED OF SWINE

1966 ◽  
Vol 46 (3) ◽  
pp. 211-216 ◽  
Author(s):  
C. W. F. Stockhausen ◽  
W. J. Boylan
Keyword(s):  
Growth Rate ◽  
Genetic Correlation ◽  
Litter Size ◽  
Negative Correlation ◽  
Backfat Thickness ◽  
Parameter Estimates ◽  
Regression Analyses ◽  
High Negative Correlation ◽  
Recent Origin

Heritability for litter size (total number born alive), postweaning growth rate, and live probe backfat thickness were estimated in a new breed of swine called Managra. The Managra is of recent origin and was developed from a crossbred foundation in which seven breeds were combined. All data used in analyses were from gilt litters. Estimates of heritability were obtained by paternal half-sib correlation and parent–offspring regression. Heritability of litter size was found to be.20 ±.15, growth rate.25 ±.04, and backfat.11 ±.04 from parent–offspring regression analyses. Estimates found by paternal half-sib correlation for the three traits were.59 ±.29,.30 ±.11, and.09 ±.19 respectively.Estimates of the genetic correlation between growth rate and backfat were obtained from the data and indicated that a moderately high negative correlation existed (about −.24).Comparisons of these parameter estimates were made with those reported from long established breeds.

A note on growth curves of rabbit lines selected on growth rate or litter size

1993 ◽  
Vol 57 (2) ◽  
pp. 332-334 ◽  
Author(s):  
A. Blasco ◽  
E. Gómez
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Growth Curves ◽  
Live Weight ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Standard Errors ◽  
Adult Weight ◽  
Weight Growth ◽  
Using Data

Two synthetic lines of rabbits were used in the experiment. Line V, selected on litter size, and line R, selected on growth rate. Ninety-six animals were randomly collected from 48 litters, taking a male and a female each time. Richards and Gompertz growth curves were fitted. Sexual dimorphism appeared in the line V but not in the R. Values for b and k were similar in all curves. Maximum growth rate took place in weeks 7 to 8. A break due to weaning could be observed in weeks 4 to 5. Although there is a remarkable similarity of the values of all the parameters using data from the first 20 weeks only, the higher standard errors on adult weight would make 30 weeks the preferable time to take data for live-weight growth curves.

Genetic relationships between wood quality traits and diameter growth of juvenile core wood in Sitka spruce

2013 ◽  
Vol 43 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S.G. Kennedy ◽  
A.D. Cameron ◽  
S.J. Lee
Keyword(s):  
Growth Rate ◽  
Genetic Correlation ◽  
Modulus Of Elasticity ◽  
Genetic Relationships ◽  
Wood Quality ◽  
Wood Properties ◽  
Sitka Spruce ◽  
Acoustic Velocity ◽  
Picea Sitchensis ◽  
Good Growth

The trend towards shorter rotations in planted conifer stands has resulted in a reduction in the proportion of mature wood relative to juvenile core wood, raising concerns that the mechanical performance of sawn battens will be affected. The potential to improve the wood quality of the juvenile core of Sitka spruce (Picea sitchensis (Bong.) Carrière) without compromising growth rate was investigated. Rapid and inexpensive indirect methods of assessing wood properties on standing trees using a Pilodyn gun and acoustic velocity were compared with direct measurements made on wood samples cut from the juvenile core. Strong genetic correlations were observed between Pilodyn gun values and direct measures of density (–0.76) and between the square of acoustic velocity and modulus of elasticity (0.73). The genetic correlation between the square of acoustic velocity and microfibril angle was also strong (–0.84). These results suggest that indirect assessments of wood properties within juvenile core wood are sufficiently reliable for these techniques to be used in the Sitka spruce breeding programme. Although a strong negative genetic correlation between diameter at breast height and density was noted (–0.79), sufficient variation exists within the breeding population to select families with both good growth rate and high modulus of elasticity wood.

scholarly journals THE EFFECT OF THE DOE WEIGHT ON HER REPRODUCTIVE EFFICIENY

2021 ◽  
Vol 22 (1) ◽  
pp. 131-142
Author(s):  
Mohammad Ebrahim Ahmed ◽  
Hussain Yawr Hussain
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Conception Rate ◽  
The Other ◽  
Gestation Period ◽  
Reproductive Efficiency ◽  
Litter Weight ◽  
The Third ◽  
Other Hand

Thirty-six local dose have been used and were divided in to three groups sacording to weight, in each group twelve dose. In the first group the weights of the dose were higher than ( 2.5 kgs) and less than (3 kgs). The second groups was higher than 3 kgs) and less than (3.5 kgs). The third group was higher than (3.5 kgs) and less than (4 kgs). The aim of this study was to obtain the effect of doe weight on her reproductive efficiency (gestation period, litter size, litter weight at birth and weaning, growth rate of offspring preweaning, conception rate and preweaning mortility).  The weight of the doe had no significant effect upon the gestation period and this period was 30.9, 31.2, 31.3 days for the three groups respectively, on the other hand the litter size was affected significantly by doe weight and litter size was at birth and preaweaning (5.1 , 5.8 and 6.2), (4.5, 5.3 and 5.7) for the three groups respectively. The offspring weight at birth and weaning was affected significantly by doe weight and this weight was (40.1 , 48.2 and 53.3 gms), (203.6, 227.5 and 233.8 gms) for the three groups respectively while the conception rate was not affected by doe weight. The mortility percentage in the prewaning period was not significantly by doe weight

Comparison of carcass and meat characteristics of three rabbit lines selected for litter size or growth rate

Meat Science ◽  
2006 ◽  
Vol 73 (4) ◽  
pp. 645-650 ◽  
Author(s):  
P. Hernández ◽  
B. Ariño ◽  
A. Grimal ◽  
A. Blasco
Keyword(s):  
Growth Rate ◽  
Litter Size

Relations between piglet weights and survival

1992 ◽  
Vol 15 ◽  
pp. 183-184 ◽  
Author(s):  
L. Rydhmer
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
Litter Size ◽  
Important Influence ◽  
Breeding Goal ◽  
Litter Traits ◽  
Size Number ◽  
Piglet Survival

The birth weight of the piglet has an important influence on many aspects of later performance. There are, for example, relations between birth weight and growth rate as well as between birth weight and litter traits at farrowing (Rydhmer, Eliasson, Stern, Andersson and Einarsson, 1989). In a shorter perspective, birth weight affects piglet survival during the first weeks of life.High Utter size (number born) is a common breeding goal. Piglet weight is related to the number of piglets in the Utter. Piglet weight is also related to survival; thus mortality increases with litter size.The aim of this work was to study variation in piglet weight, some factors that may influence piglet weight and relations between litter size, piglet weight and piglet survival.Individual piglet weights were registered in 747 litters from an experimental farm. Of the 8134 piglets born, 2326 were Swedish Yorkshire, 239 Swedish Landrace, and the rest were crosses between these two breeds. One-third of the piglets were born in gilt litters. The piglets were creep fed from the 2nd week and weaned at 6 weeks of age. They were individually weighed at birth and at 3, 6 and 9 weeks of age. Birth weight in this report refers to the weight of all piglets born, including those stillborn.

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