SCALING EFFECTS AND THE INHERITANCE OF JUVENILE BODY WEIGHT IN CHICKENS

1970 ◽  
Vol 12 (4) ◽  
pp. 724-727 ◽  
Author(s):  
I. F. Carte ◽  
P. B. Siegel
Keyword(s):  
Body Weight ◽  
High Weight ◽  
Scaling Effects ◽  
High Line ◽  
Low Weight ◽  
Selection For

Data are presented for 10 generations of selection for high and low body weight at 8 weeks of age. The response of males was greater than that of females in the high weight line, but not in the low weight line. The asymmetrical response of sexes in the high weight line was eliminated by adjustment for scaling effects. Although heritabilities were greater in the high line than in the low line, they were essentially equal for both sexes within a line.

SELECTION FOR SERUM CHOLESTEROL, VOLUNTARY PHYSICAL ACTIVITY, 56-DAY BODY WEIGHT AND FEED INTAKE IN RANDOMBRED MICE. II. CORRELATED RESPONSES

1981 ◽  
Vol 23 (3) ◽  
pp. 545-555 ◽  
Author(s):  
E. A. Dunnington ◽  
J. M. White ◽  
W. E. Vinson
Keyword(s):  
Physical Activity ◽  
Body Weight ◽  
Serum Cholesterol ◽  
Feed Intake ◽  
High Weight ◽  
Control Line ◽  
High Intake ◽  
Low Weight ◽  
Voluntary Physical Activity ◽  
High Feed

Randomly bred ICR mice were selected for five generations for high and low serum cholesterol (SC), voluntary physical activity, 56-day body weight and feed intake. An unselected, randomly bred control line was maintained with each pair of selection lines. Significant increases in mature body weight occurred in males of high weight and high intake lines and in females of high SC, high weight and high intake lines. Significant decreases in mature body weights occurred in males of low weight line and in females of low SC and low weight lines. Both high and low selected SC lines had greater (P<0.05) activity scores and consumed more feed than the SC control. Mice selected for high activity consumed more (P<0.05) feed than mice selected for low activity. Mice selected for high 56-day body weight consumed more (P<0.05) feed and had higher SC than mice selected for low 56-day body weight. Mice selected for high feed intake were heavier (P<0.05) and more active (P<0.05) than low feed intake mice but had significantly lower SC levels.

scholarly journals Cholesterol content in eggs produced by hens divergently selected for body weight (Short Communication)

2010 ◽  
Vol 53 (6) ◽  
pp. 701-707
Author(s):  
D. Terčič ◽  
A. Levart ◽  
A. Holcman
Keyword(s):  
Body Weight ◽  
Short Communication ◽  
Cholesterol Content ◽  
Weight Percent ◽  
Divergent Selection ◽  
Shell Weight ◽  
Low Weight ◽  
Selection For ◽  
Egg Components ◽  
Chicken Eggs

Abstract. In this work the cholesterol content of chicken eggs produced by two lines (high and low weight) representing the 31st generation of selection for divergent growth was studied. Divergent selection for body weight at 8 weeks of age resulted in changes in egg size and consequently in the weight of egg components. Higher values (P≤0.001) were observed in eggs from the high weight (D+) line for egg weight, albumen, yolk and shell weight. Percent yolk was greater (P≤0.001) and percent albumen was lower (P≤0.001) in eggs from the low weight (D−) line. Eggs from the D− line contained lower (P≤0.001) cholesterol content (mg/ egg, mg/g yolk, mg/g yolk dry matter) than eggs from the D+ line but when cholesterol was expressed in milligrams per gram of egg or per gram of edible egg, differences between the two lines were not significant. Divergent selection for body weight changed the albumen : yolk ratio and a change of this type affected the grams of cholesterol per gram of yolk values.

Reproductive performance, growth rate and body composition of broiler breeder hens differing in body weight at 21 weeks of age

1991 ◽  
Vol 71 (4) ◽  
pp. 1223-1231 ◽  
Author(s):  
F. E. Robinson ◽  
N. A. Robinson
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Reproductive Performance ◽  
High Weight ◽  
Embryo Viability ◽  
Broiler Breeder ◽  
Breeder Hens ◽  
Low Weight ◽  
Broiler Breeder Hens ◽  
Medium Weight

The effects of variation in body weight at 21 weeks of age on subsequent growth rate, body composition and reproductive performance were studied in broiler breeder hens from 22 to 62 weeks of age. Pullets were sorted into three groups on the basis of body weight (low, medium and high) at 21 weeks of age. Pullets of the low-weight group contained a greater percentage of carcass water and less carcass fat at 22 weeks of age than did the medium- and high-weight pullets, and less carcass protein than the high-weight birds. The relative difference in body weight between the three groups of hens was maintained to 62 weeks of age, the high-weight hens being heavier than the low- and medium-weight hens at the end of the study. The low-weight birds began to lay later than the medium- and high-weight pullets. The low- and medium-weight birds were lighter in weight compared to the high-weight pullets at sexual maturity. Total egg output was lower in the low-weight hens than in the medium- and high-weight hens. No difference was seen in sequence and intersequence pause parameters or in fertility, embryo viability or embryo production between the three groups of hens. On a percentage basis, there were no differences in body composition between groups of birds at 62 weeks of age. It was concluded that pullets which are underweight at 21 weeks of age exhibit a poorer production record than do pen-mates which are of normal or greater than normal body weight. Key words: Broiler breeder hens, egg production, body weight, body composition, sequence length, fertility, embryo viability

Artificial selection for intrinsic aerobic endurance running capacity in rats

2001 ◽  
Vol 5 (1) ◽  
pp. 45-52 ◽  
Author(s):  
LAUREN GERARD KOCH ◽  
STEVEN L. BRITTON
Keyword(s):  
Body Weight ◽  
Artificial Selection ◽  
High Capacity ◽  
Founder Population ◽  
Endurance Running ◽  
Family Selection ◽  
High Line ◽  
Selection For ◽  
Coefficient Of Inbreeding

Artificial selection for intrinsic aerobic endurance running capacity was started using genetically heterogeneous N:NIH stock of rats as a founder population ( n = 168). Selection for low and high capacity was based upon distance run to exhaustion on a motorized treadmill using a velocity-ramped running protocol. The starting velocity was 10 m/min and was increased by 1 m/min every 2 min (slope was constant at 15°). At each generation, within-family selection was practiced using 13 families for both the low and high lines. A rotational breeding paradigm maintained the coefficient of inbreeding at less than 1% per generation. On average the founder population ran to exhaustion in 355 ± 11 m. Six generations of selection produced lines that differed in running capacity by 171%, with most of the change occurring in the high line. At generation 6 the low line ran 310 ± 8 m and the high line 839 ± 21 m at exhaustion. Selection for running capacity produced changes in body weight as a correlated trait. By generation 6, the low-line females were 20% heavier than the high-line females, and the low-line males were 16% heavier than the high-line males.

ESTIMASI NILAI HERITABILITAS BOBOT IKAN MAS VARIETAS PUNTEN DALAM PROGRAM SELEKSI INDIVIDU

2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Base Population ◽  
Breeding Programs ◽  
Male And Female ◽  
Body Weight Trait ◽  
Population Selection ◽  
Selection For ◽  
Weight Trait ◽  
Selection Of

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).

scholarly journals SELECTION FOR BLOOD PRESSURE LEVELS IN MICE

Genetics ◽  
1974 ◽  
Vol 76 (3) ◽  
pp. 537-549
Author(s):  
Gunther Schlager
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Population Bottleneck ◽  
Control Line ◽  
Selected Lines ◽  
High Line ◽  
Selection For ◽  
Random Control

ABSTRACT Response to two-way selection for systolic blood pressure was immediate and continuous for about eight generations. In the twelfth generation, the High males differed from the Low males by 38 mmHG; the females differed by 39 mmHg. There was little overlap between the two lines and they were statistically significant from each other and from the Random control line. There appeared to be no more additive genetic variance in the eleventh and twelfth generations. Causes for the cessation of response are explored. This is probably due to a combination of natural selection acting to reduce litter sizes in the Low line, a higher incidence of sudden deaths in the High line, and loss of favorable alleles as both selection lines went through a population bottleneck in the ninth generation.—In the eleventh generation, the selected lines were used to produce F1, F2, and backcross generations. A genetic analysis yielded significant additive and dominance components in the inheritance of systolic blood pressure.

Influence of selection for body weight at different ages on growth of Turkeys

1963 ◽  
Vol 4 (1) ◽  
pp. 71-82 ◽  
Author(s):  
H. Abplanalp ◽  
F. X. Ogasawara ◽  
V. S. Asmundson
Keyword(s):  
Body Weight ◽  
Different Ages ◽  
Selection For
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