scholarly journals Effect of selection for development rate on reproductive onset in female mice

1999 ◽  
Vol 74 (1) ◽  
pp. 55-64 ◽  
Author(s):  
C. A. ERNST ◽  
P. D. CRENSHAW ◽  
W. R. ATCHLEY
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Slow Growth ◽  
Body Weight Gain ◽  
Correlated Response ◽  
Balance Growth ◽  
Vaginal Opening ◽  
Reproductive Onset ◽  
Mature Weight ◽  
Selection For

This research reports analyses of correlated response in reproductive onset in ICR mice after 23 generations of restricted index selection for divergent body weight gain, early (birth–10 days) or later (28–56 days) in life. Long-term selection altered growth trajectories and 56 day body weight of individuals under different selection regimes in this study. Mice in lines under early selection have the same percentage mature weight at vaginal opening as controls (63%). Vaginal opening is delayed in mice selected for slow early growth, which take longer to reach what appears to be a weight threshold. In contrast, individuals in lines selected for later slow growth undergo vaginal opening at the same age as controls, but at a lower weight and increased percentage mature weight. Pre-compensation or ‘counter-balance growth’ is observed in these lines, with mice selected for late enhanced growth reaching 52% of mature weight at vaginal opening while mice with late slow growth attain 71% of mature weight prior to vaginal opening. Only 42% of mice with late slow growth attain first oestrus by 56 days. We speculate this is a function of growth rate and fat/lean ratio. Mice with early slow growth show compensatory growth, reaching first oestrus at a similar time to controls. We conclude that selection for growth rate has asymmetrically affected reproductive onset, with lines selected for suppressed gains experiencing delays in the reproductive onset traits measured.

Selection for components of efficient lean growth rate in pigs 2. Selection pressure applied and direct responses in a Landrace herd

1994 ◽  
Vol 59 (2) ◽  
pp. 263-269 ◽  
Author(s):  
N. D. Cameron ◽  
M. K. Curran
Keyword(s):  
Growth Rate ◽  
Genetic Correlations ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Direct Response ◽  
Lean Growth ◽  
Ad Libitum ◽  
Selection For ◽  
Ad Libitum Feeding

AbstractResponses to divergent selection for lean growth rate with ad-libitum feeding (LGA), for lean food conversion (LFC) and for daily food intake (DFI) in Landrace pigs were studied. Selection was practised for four generations with a generation interval ofl year. A total of 2642 pigs were performance tested in the high, low and control lines, with an average of 37 boars and 39 gilts performance tested per selection line in each generation. The average within-line inbreeding coefficient at generation four was equal to 0·04. There was one control line for the DFI and LFC selection groups and another control line for the LGA selection group. Animals were performance tested in individual pens with mean starting and finishing weights of 30 kg and 85 kg respectively with ad-libitum feeding. The selection criteria had phenotypic s.d. of 32, 29 and 274 units, for LGA, LFC and DFI, respectively, and results are presented in phenotypic s.d.Cumulative selection differentials (CSD) were 5·1, 4·5 and 5·5 phenotypic s.d. for LGA, LFC and DFI, respectively. Direct responses to selection were 1·4,1·1 and 0·9 (s.e. 0·20) for LGA, LFC and DFI. In each of the three selection groups, the CSD and direct responses to selection were symmetric about the control lines. The correlated response in LFC (1·1, s.e. 0·19) with selection on LGA was equal to the direct response in LFC. In contrast, the direct response in LGA was greater than the correlated response (0·7, s.e. 0·18) with selection on LFC. There was a negative correlated response in DFI (-0·6, s.e. 0·18) with selection on LFC, but the response with selection on LGA was not significant (0·2, s.e. 0·16).Heritabilities for LGA, LFC and DFI ivere 0·25, 0·25 and 0·18 (s.e. 0·03), when estimated by residual maximum likelihood, with common environmental effects of 0·12 (s.e. 0·02). Genetic correlations for LFC with LGA and DFI were respectively positive (0·87, s.e. 0·02) and negative (-0·36, s.e. 0·09), while the genetic correlation between DFI and LGA was not statistically different from zero, 0·13 (s.e. 0·10). Selection on components of efficient lean growth has identified LGA as an effective selection objective for improving both LGA and LFC, without a reduction in DFI.

Selection for lean growth rate and correlated responses in litter traits in a synthetic line of Yorkshire-Meishan pigs

2001 ◽  
Vol 81 (2) ◽  
pp. 205-214 ◽  
Author(s):  
P. Chen ◽  
T. J. Baas ◽  
J. C. M. Dekkers ◽  
L. L. Christian
Keyword(s):  
Growth Rate ◽  
Regression Coefficients ◽  
Correlated Response ◽  
Selection Line ◽  
Control Line ◽  
Correlated Responses ◽  
Lean Growth ◽  
Litter Traits ◽  
Selection For ◽  
Synthetic Line

Selection for lean growth rate (LGR) was conducted for four generations in a synthetic line of Yorkshire-Meishan pigs to study the effectiveness of selection for LGR and correlated responses in litter traits. Lean growth rate was estimated from ultrasound measurements of 10th-rib backfat thickness and longissimus muscle area. In the selection line, 7 boars and 20 gilts with the highest LGR were selected to produce the next generation. The generation interval was 13 mo and the average selection differential per generation was 1.1 phenotypic standard deviation units. A contemporaneous control line was maintained by randomly selecting 5 boars and 15 gilts. Data from a total of 1057 pigs sired by 58 boars and out of 133 sows were available from the two lines. Selection responses were estimated from deviations of the selection line from the control line using least squares (LS) and by multiple trait derivative-free restricted maximum likelihood analysis using an animal model (AM). The estimate of response to selection per generation using LS was 9.4 ± 0.95 g d–1 for LGR. The corresponding estimate from the AM was 9.8 ± 0.51 g d–1. Correlated responses in litter traits were regressed on generation. For the LS method, regression coefficients were negative but not significant (P > 0.05) for total number born, number born alive, and number at 21 d and at 42 d. Significant, positive correlated responses occurred in 42-d litter weight and 21-d piglet weight (P < 0.05). For the AM method, the regression coefficients were also negative, but were not significant (P > 0.05) for numberalive at birth, at 21 d, and at 42 d. A significant positive correlated response occurred only for 42-d litter weight (P < 0.05). Although results are based on a population of limited size, it can be concluded that selection for LGR in a synthetic line is effective and should have little effect on litter traits. Key words: Pigs, selection, lean growth rate, correlated response

scholarly journals Altering Developmental Trajectories in Mice by Restricted Index Selection

Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 629-640
Author(s):  
William R Atchley ◽  
Shizhong Xu ◽  
David E Cowley
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Weight Gain ◽  
Complex Traits ◽  
Body Weight Gain ◽  
Developmental Trajectories ◽  
Cell Number ◽  
Index Selection ◽  
Early Postnatal Development ◽  
Rate Of Development

A restricted index selection experiment on mice was carried out for 14 generations on rate of early postnatal development (growth rate from birth to 10 days of age) vs. rate of development much later in ontogeny (growth rate from 28 to 56 days of age). Early rate of development (E) approximates hyperplasia (changes in cell number) and later rate (L) reflects hypertropy (changes in cell size). The selection criteria were as follows: E+L0 was selected to increase early body weight gain while holding late body weight gain constant; E–L0 was selected to decrease early body gain while holding late gain constant; E0L+ was selected to increase late gain holding early gain constant; and E0L– was selected to decrease late gain holding early gain constant. After 14 generations of selection, significant divergence among lines has occurred and the changes in the growth trajectories are very close to expectation. The genetic and developmental bases of complex traits are discussed as well as the concept of developmental homoplasy.

scholarly journals DYNAMICS OF GROWTH IN THE GOUSES UNDER CONDITIONS OF THE COMBINED PHARMACOPROPHYLACTIC HOMOBIOTICS, PROBIOTICS BASED ON THE RECOMBINANT BASILL AND ENROFLOXACIN STRAIN

2019 ◽  
pp. 104-110
Author(s):  
G. A. Nozdrin ◽  
N. A. Gotovchikov ◽  
M. S. Yakovleva ◽  
N. S. Yakovleva ◽  
M. B. Lazareva
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Weight Gain ◽  
Body Weight Gain ◽  
Physiological State ◽  
Average Daily Gain ◽  
Live Weight ◽  
Absolute Weight ◽  
Probiotic Preparation ◽  
Daily Gain

The combined effect of homobiotics, probiotics based on recombinant strains of g. Bacillus, & enrofloxacin on the dynamics of body weight gain in geese was studied. According to the principle of steam-analogs, one control and five experimental groups of 10 goslings in each group were formed. Gosyatam experimental groups used homobiotics vetom 15.1; vetom 13.1 incombination with enrofloxacin followed by replacement with a probiotic preparation Vetom 1.2. The absolute body weight and average daily gain in geese under the influence of the studied drugs increases. The severity of the effect depended on the pharmacological composition of the drugs used. The maximum absolute weight gain was observed when using the drugs according to the scheme: vetom 13.1 at doses of 25–50 mg/kg for 16 days, with further use of a 10% enrofloxacin solution at a dose of 0.5 ml/kg for 5 days and in The experiment period was 1.2 at a dose of 50 mg/kg for 16 days. After the cessation of the use of drugs, the growth rate increased for 30 days when prescribing the drugs according to the scheme: veto 13.1 at a dose of 50 mg/kg for 16 days and with further introduction of homobiotic veto 1.2 into the bird in a dose of 50 mg/kg for 16 days. The maximum average daily gain in live weight of geese was observed in the period from the 16th to the 32nd day with the administration scheme: homobiotic vetom 13.1 at a dose of 25 mg/kg of body weight 1 time per day for 5 consecutive days, then every other day for 16 days, then daily 10 % solution of enrofloxacin at a dose of 0.5 ml/kg of body weight for 5 days, then vetom 1.2 at a dose of 25 mg/kg once a day for 16 days in a row. And the maximum average daily gain in the post using period of the drug was observed on the 32nd day of the study according to the scheme: homobiotic veto 15.1 at a dose of 50 mg/kg of body weight 1 time per day for 16 days, then daily with vetom 1.2 at the same dose 1 once a day for 16 days. The studied drugs in the applied doses did not have a toxic effect on the physiological state of geese.

Insulin, growth hormone, glucose, and fatty acids in gilts selected for rapid vs. slow growth rate

1989 ◽  
Vol 257 (4) ◽  
pp. E554-E560
Author(s):  
S. A. Norton ◽  
M. T. Zavy ◽  
C. V. Maxwell ◽  
D. S. Buchanan ◽  
J. E. Breazile
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Growth Rate ◽  
Slow Growth ◽  
Insulin Level ◽  
Growth Line ◽  
Slow Growth Rate ◽  
Selection For ◽  
Plasma Gh ◽  
Profile Area

Twelve-hour plasma profiles of growth hormone (GH), insulin, glucose, and nonesterified free fatty acids (NEFA), as well as GH, insulin, and glucose responses to saline, glucose, arginine, and human pancreatic growth hormone-releasing factor (GRF) infusion were examined in 15 crossbred gilts, selected for rapid vs. slow growth. For experiment 1 GH and insulin patterns differed (P less than 0.05) between the rapid growth line (RGL) and slow growth line (SGL). Mean GH concentrations in SGL and RGL gilts were 4.1 and 3.2 ng/ml, respectively (P less than 0.05). Plasma GH profile area was greater (P less than 0.08) for SGL than RGL gilts. Glucose level, glucose area, and insulin level were higher (P less than 0.05) for RGL than SGL gilts. Plasma NEFA levels and area were greater (P less than 0.05) for SGL gilts. In experiment 2 responses of GH, insulin, and glucose to saline, glucose, arginine, and GRF infusions varied (P less than 0.05) between and within lines relative to control values. These results indicate that selection for growth rate results in concomitant changes in endocrine and metabolic status.

scholarly journals Comparative Study On Nursing Of Different Strains Of Tilapia (Oreochromis niloticus) In Bangladesh

2016 ◽  
Vol 5 (2) ◽  
pp. 98-106
Author(s):  
MA Hossain ◽  
MJ Islam ◽  
MM Uddin ◽  
MM Hossain ◽  
M Kunda
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Survival Rate ◽  
Body Weight Gain ◽  
Stocking Density ◽  
Experimental Period ◽  
Mustard Oil ◽  
Feed Conversion ◽  
Different Strains ◽  
The Individual

This study was conducted to investigate and compare the growth performance of four Tilapia strains in hapa nursing with the aim to find out the best strain of tilapia. The research was conducted by four treatments with five replicates each. The tilapia fry were collected from, BFRI source from BFRI HQ, Mymensingh stocked in Treatment-1; unknown source from Hi-Tech Tilapia Hatchery Dagoanbhuiya, Feni in Treatment-2, Philipine strain from Green Field Tilapia Hatchery, Laxmipur in Treatment-3 and fry from Breeding Cohort, Sonar Bangla Hatchery, Bamna, Barguna in Treatment-4. The Individual stocking weight (g) of fry was average 0.01g. The fries were stocked in 12 hapa at same stocking density of 1200 fish/m2. Each of the hapa was 2m × 1m × 1m size and fixed in an earthen ponds. Supplementary feed with 31.29% of protein level consisting of rice bran (25%), mustard oil cake (15%), wheat flour (30%) and fish meal (30%) was given at the rate of 40% of their body weight per day manually, four times a day at the beginning of the experimental period and reduced to 25% of their body weight and continued up to harvesting period. The results showed that fry of Treatment-4 strain was the best strain and had significantly (p < 0.05) higher final mean body weight (FMBW), mean body weight gain (MBWG), specific growth rate (SGR) (9.75%), gross yield (GY) (2.13) and Net yield (NY) (2.12) than the Treatment-1 , Treatment-2 strains and Treatemnt-3 strain. Treatment-4 strain had the fastest growth rate, whereas the lowest performing strain was that from Treatment-2. We also analyzed survival rate of the fish from stocking to harvest, survival rate was highest in Treatment-4 strain (80%) where lowest is Treatment-3. Treatment-4 stain also showed the best feed conversion ratio (FCR) 1.62 than others. Considering the overall performance it can be concluded that tilapia strain collected from Breeding Cohort source is best among the four strains. However, further research may still be needed to compare more strains from different water body to evaluate the genetic potential for Tilapia.International Journal of Natural Sciences (2015), 5(2) 98-106

CORRELATED RESPONSES IN EGG QUALITY TRAITS TO SELECTION FOR EARLY BODY WEIGHT IN MEAT-TYPE CHICKENS

1972 ◽  
Vol 14 (3) ◽  
pp. 477-482 ◽  
Author(s):  
V. Buvanendran ◽  
E. S. Merritt
Keyword(s):  
Body Weight ◽  
Egg Quality ◽  
Correlated Response ◽  
Quality Traits ◽  
Correlated Responses ◽  
Egg Weight ◽  
Shell Color ◽  
Blood Spots ◽  
Selection For ◽  
Meat Type

The correlated responses in egg quality traits to selection for high early body weight were studied in seven meat-type populations comprising five selected and two control lines. Traits studied were specific gravity, egg weight, albumen height, Haugh units, shell color, egg shape, shell roughness, wrinkling and asymmetry, and incidence of blood spots, meat spots and double yolks. Significant (P < 0.05 or < 0.01) correlated changes, as determined by the regression of correlated response (egg quality traits) on primary response (body weight), were obtained for egg weight, albumen height, Haugh units, asymmetry of shell and blood spots. All but blood spots increased with selection for high body weight. Shell color showed a consistent trend towards a darker color with increasing body weight. Scores for roughness of shell and, with one minor exception, the incidence of double yolks, also showed consistent trends (positive) with increasing body weight. Estimates of genetic correlations, derived directly from intra-line genetic analyses of the six pedigreed populations in the experiment, were in most cases in reasonable agreement with realized estimates.

Effects of glucocorticoid on body growth and serum levels of somatomedin A in the rat

1982 ◽  
Vol 100 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Kumiko Asakawa ◽  
Kazue Takano ◽  
Megumi Kogawa ◽  
Yoko Hasumi ◽  
Kazuo Shizume
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Weight Gain ◽  
Body Weight Gain ◽  
Serum Levels ◽  
Radioreceptor Assay ◽  
Body Growth ◽  
Cortisone Acetate ◽  
Combined Administration ◽  
A Minor

Abstract. Serum levels of somatomedin A, as measured by radioreceptor assay, and body weight gain were 86.5 ± 9.2% and 166.9 ± 7.8% (N = 5) of the initial values, respectively, after 18 days administration of 2.5 mg cortisone acetate (CA). These values were significantly lower than those for saline treated rats (P < 0.005). Reduced serum somatomedin A and body growth rate were partially restored after halting the injection of CA. Combined administration of daily doses of 100 μg hGH with CA did not prevent the decrease in somatomedin activity in treated rats. This observation suggests that GH plays a minor (or no) role in the fall of serum somatomedin A in CA-treated rats. From these data we conclude that glucocorticoids reduce serum somatomedin by inhibiting the effect of GH on the generation of somatomedin.

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