DIRECT GENETIC AND POSTNATAL MATERNAL GENETIC EFFECTS ON BODY COMPOSITION IN MICE SELECTED FOR BODY WEIGHT

1979 ◽  
Vol 21 (1) ◽  
pp. 43-56 ◽  
Author(s):  
J. F. Hayes ◽  
E. J. Eisen
Keyword(s):  
Body Weight ◽  
Genetic Effects ◽  
The Body ◽  
Control Line ◽  
Ether Extract ◽  
Correlated Responses ◽  
Relative Growth Rates ◽  
Order Of Magnitude ◽  
Body Components ◽  
Water Percent

Line crossfostering techniques were used to study differences among selected and control lines of mice in direct genetic and postnatal maternal genetic influences on preweaning (day 12) body weight and composition. The lines were selected for high (H6) and low (L6) 6-week body weight and the control line (C2) was maintained by random selection. There were positive correlated responses to selection in both direct genetic and postnatal maternal genetic effects on body weight and weights of all body components (P < 0.01) except for water and ash weight in H6. The correlated responses in postnatal maternal genetic effects were of the same order of magnitude as those in direct genetic effects. Correlated responses were greater in L6 than in H6. Correlated responses in direct genetic effects were positive (P < 0.01) for water percent in H6 and ether extract percent in L6, and negative (P < 0.01) for water percent and lean percent in L6. Correlated responses in postnatal maternal genetic effects were positive for ether extract percent and negative for water percent (P < 0.01). Correlated responses were far greater in L6 than in H6 and were greater for postnatal maternal genetic effects than for direct genetic effects. Analyses of covariance results indicated line differences in the relative growth rates of the body components.

II.—Genetics of Gametes. II. Strain Differences in Characteristics of Rabbit Spermatozoa

1961 ◽  
Vol 68 (1) ◽  
pp. 17-24 ◽  
Author(s):  
R. A. Beatty ◽  
R. A. N. Napier
Keyword(s):  
Body Weight ◽  
Strain Differences ◽  
Genetic Effects ◽  
The Body ◽  
Size And Shape ◽  
Rabbit Spermatozoa

SynopsisThe study of genetic effects on the phenotype of gametes may be called the genetics of gametes. As evidence of such genetic effects, marked inter-strain differences have been demonstrated in characteristics of rabbit spermatozoa examined in nigrosin-eosin preparations. Strain differences have been found in the size and shape of the spermatozoan head, and in a measure of spermatozoan viability—the incidence of stained heads. A first comparison of the spermatozoa of specific breeds is given. The size of the spermatozoan head is to some extent independent of the body weight.

Body composition of young sheep: I. Body composition in merino and Border Leicester × Merino hoggets in relation to and at common empty body weight

1969 ◽  
Vol 72 (1) ◽  
pp. 65-75 ◽  
Author(s):  
H. R. Gharaybeh ◽  
W. R. McManus ◽  
G. W. Arnold ◽  
M. L. Dudzinski
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Chemical Composition ◽  
Total Energy ◽  
Crude Protein ◽  
Whole Body ◽  
Ether Extract ◽  
Internal Organs ◽  
Breed Differences ◽  
Body Components

SUMMARYFlocks of 9-month-old Merino and Border Leicester & Merino sheep were sampled over the full range of body weights present within flocks. Six pairs of ewes and wethers of equal body weight were taken. The sheep were weighed and slaughtered after a 36 h fast. Total weights of blood, skin, head, feet, internal organs and carcasses were obtained for each animal. Each component was analysed for ash, crude protein, ether extract and total energy. Half of each carcass was dissected into bone, muscle, fat and waste.The compositions of the sheep were compared by regression analyses of weights of body components on empty body weight (EBW) between the four groups and by means of percentages of EBW. There were highly significant linear relationships between both fresh and dry weights of body components, carcass components, and chemical components with EBW; moisture content was not related to EBW. Rates of change with EBW in weights of body components, or in amounts of ash, crude protein, ether extract and energy were the same for all groups of sheep with the exceptions of bone and skin ether extract (EE) weight. However, intercepts of regression lines frequently differed, indicating that body composition differed between groups at the same EBW.All groups had the same dry weight of blood, internal organs and muscle, weight of ether extract, and total energy in the whole body at the same EBW. Border Leicester × Merinos had lighter skins with less wool, but their carcass weights were higher than Merinos. There were other differences between breeds in the chemical composition of individual components. Wethers had heavier head + feet weights and carcass bone than had ewes. There were also some sex differences in chemical composition of body components. In general, there were fewer sex than breed differences in body composition. The breed differences cannot be explained on the basis of early and later maturing types.

The effect of pre- and post-natal nutrition on the growth of beef cattle. 3. The effect of severe restriction in early post-natal life on the development of the body components and chemical composition

1980 ◽  
Vol 31 (1) ◽  
pp. 191 ◽  
Author(s):  
GD Tudor ◽  
DW Utting ◽  
PK O'Rourke
Keyword(s):  
Body Weight ◽  
Carcass Composition ◽  
The Body ◽  
Fat Free Mass ◽  
Carcass Weight ◽  
Feeding Period ◽  
Castrate Male ◽  
Before And After ◽  
Body Components ◽  
Female Cattle

The effects of restricted growth of cattle both before and after birth, of the method of their realimentation, and of sex on (1) body and carcass composition, (2) the weights of visceral components, (3) the weights of selected individual muscles and bones, and (4) the heights of the animals at the withers and pelvis were ascertained. Castrate male and entire female cattle were slaughtered when their liveweights reached 400 and 370 kg respectively. Other male and female calves were slaughtered at 200 days of age following a controlled feeding period on either a high or a low plane diet. Although pre-natal nutrition significantly (P < 0.05) affected the height of the calves at 3 days of age, it had no lasting effect on this or other components. When adjusted to the same empty body weight or carcass weight, animals restricted in growth then intensively realimented had (P < 0.01) more fat and less protein, water and ash than animals unrestricted in growth and later fed intensively. Animals finished on pasture had (P < 0.01) less fat and more protein, water and ash than the intensively finished calves, but their composition was unaffected by the controlled feeding treatments. Significant differences (P < 0.01) between restricted and unrestricted animals in the percentage water or protein in the fat-free mass at the end of the controlled feeding period were eliminated when the animals had recovered. The weights of visceral components, individual muscles and bones were not influenced by the level of nutrition during the controlled feeding period. Animals finished on pasture had (P < 0.01) more blood, heavier livers, heavier individual muscles and bones than the intensively finished animals. They also had (P < 0.01) lighter fasted liveweight, empty body weight, hot carcass weight, dressing percentage and heavier wet rumen-reticulum contents than the intensively finished cattle. Although the pasture finished animals were (P < 0.01) shorter at 200 and 300 days of age than the intensively finished animals, they were (P < 0.01) taller just prior to slaughter. It is suggested that meat-producing animals can overcome restrictions imposed on growth immediately after birth to attain marketable weight on either pasture or intensive feeding.

GENETIC ANALYSIS OF NURSE DAMS SELECTED FOR SIX-WEEK BODY WEIGHT OR POSTWEANING GAIN IN MICE

1976 ◽  
Vol 18 (4) ◽  
pp. 611-623 ◽  
Author(s):  
J. Nagai ◽  
H. Bakker ◽  
E. J. Eisen
Keyword(s):  
Body Weight ◽  
Feed Intake ◽  
Selection Response ◽  
Genetic Effects ◽  
Control Group ◽  
Correlated Response ◽  
Population Differences ◽  
Correlated Responses ◽  
Maternal Performance ◽  
And Control

A modified crossfostering technique was developed to compare the performance of nurse dams in selected and control populations of mice. The H6 and M16 populations were selected for increased 6-week body weight and 3- to 6-week postweaning gain, respectively, while the C2 and ICR populations were the respective controls. Crossfostering was performed using H6, M16 and their reciprocal F1 crosses as nurse dams in the selected crossfostering group and C2, ICR and their reciprocals in the control group. Measurements recorded for nurse dams included mean body weight of 8 young within a nursed litter at birth (MWB) and 12 days of age (MW12). The latter was used as a measure of postnatal maternal performance. Other traits recorded for nurse dams were number born (NB), body weight at parturition (DWP) and 12 days postpartum (DW12), and weight gain (DWG), feed intake (FED) and efficiency (EFF = DWG/FED) for the first 12 days of lactation. The correlated response in MW12 was negative (P <.01) for M16 and essentially zero for H6. Both lines exhibited positive (P <.01) correlated responses in DWP and DW12 and no change in EFF. Only the H6 line increased significantly in DWG and FED as a result of selection. NB increased in M16 and H6, but was significant for the latter population only. Population differences in selection response [(M16-ICR)-(H6-C2)] were significant for FED only, primarily due to average direct genetic effects. Direct comparisons of M16 and H6 indicated that M16 was larger in DWP and DW12 but smaller in DWG and EFF. Average direct genetic effects favored M16 for NB, DWP, and DW12, whereas average maternal genetic effects favored H6 for NB, DWP, DW12 and FED. Percent direct heterosis in F1 crosses of the selected populations was significant for MW12 (13.7%), FED (10.8%) and NB (11.4%). Direct heterosis in F1 crosses of the controls was significant for MW12 (9.4%), NB(6.6%), DWP (3.5%), DW12 (3.3%) and FED (4.4%). The effects of MW12, DWG and metabolic body size (MBS) accounted for 47% of the variation in FED, pooled within populations. Of these variables, MW12 accounted for the highest proportion (32%) of variation in total feed intake.

Genetic relations between carcass fat and body weight in mice

1960 ◽  
Vol 55 (3) ◽  
pp. 317-321 ◽  
Author(s):  
P. Hull
Keyword(s):  
Body Weight ◽  
Genetic Relationship ◽  
Abdominal Fat ◽  
Carcass Composition ◽  
The Other ◽  
Theoretical Treatment ◽  
Control Line ◽  
Correlated Responses ◽  
Age Changes ◽  
Body Weights

Three different stocks of mice were selected for five generations for high body weight at 3, 4½, or 6 weeks of age. Changes in body weight at the three ages and in abdominal fat weight, an index of carcass composition, which occurred in the three lines were compared. It was found that the proportion of fat in the carcasses of the selected animals increased markedly in the lines selected for high 3-week weight, while in the other two lines the proportion remained the same as that in the control line.The theoretical treatment of the genetic relationship between body weights at different ages and between body weight and abdominal fat was reasonably adequate in accounting for the correlated responses actually observed.

Growth patterns in sheep: changes in the chemical composition of the empty body and its constituent parts during weight loss and compensatory growth

1984 ◽  
Vol 103 (1) ◽  
pp. 17-24 ◽  
Author(s):  
B. W. Butler-Hogg
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Chemical Composition ◽  
Chemical Constituents ◽  
Growth Patterns ◽  
The Body ◽  
Control Group ◽  
Relative Contribution ◽  
Body Components ◽  
Three Body

SummaryChemical compositional (protein, fat, ash and water) changes in the fleece-free empty body, carcass, viscera and ‘remainder’ components of Corriedale wether sheep were measured by serial slaughter of animals following five different growth paths.The composition of sheep, after losing up to 34% of body weight over 18 weeks at 125 g/day, was significantly different from a continuously growing control group at the same body weight, but the actual differences in the weights of tissues were small. At the end of weight loss all treatment sheep contained more fat and protein, and less water than controls.The different growth paths followed during weight loss led to differences in the proportions of protein, fat, ash and water lost and to differences between the three body components in the relative contribution made by each.The periods of weight loss led to changes in the relative growth coefficients for chemical constituents during realimentation, particularly those of fat and ash which were reduced, and of water which was increased.The response to realimentation differed between body components, particularly the carcass and viscera. Above the body weight at which weight loss was imposed the realimented sheep did not differ in chemical composition from the continuously ad libitum fed controls when compared at the same weight.

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON CORRELATED RESPONSES TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽  
1973 ◽  
Vol 74 (1) ◽  
pp. 157-170
Author(s):  
E J Eisen ◽  
J P Hanrahan ◽  
J E Legates
Keyword(s):  
Body Weight ◽  
Population Size ◽  
Effective Population Size ◽  
Litter Size ◽  
The Body ◽  
Selection Intensity ◽  
Correlated Responses ◽  
Effective Population ◽  
Population Sizes ◽  
Selection For

ABSTRACT Correlated responses to selection for postweaning gain in mice were studied to determine the influence of population size and selection intensity. Correlated traits measured were three-, six- and eight-week body weights, litter size, twelve-day litter weight, proportion infertile matings and two indexes of reproductive performance. In general, the results agreed with observations made on direct response: correlated responses in the body weight traits and litter size increased as (1) selection intensity increased and (2) effective population size increased. Correlated responses in the body weight traits and litter size were positive in the large population size lines (16 pairs), as expected from the positive genetic correlation between these traits and postweaning gain. However, several negative correlated responses were observed at small population sizes (one and two pairs). Within each level of selection intensity, traits generally associated with fitness tended to decline most in the very small populations (one and two pairs) and in the large populations (16 pairs) for apparently different reasons. The fitness decline at the small effective population sizes was attributable to inbreeding depression. In contrast, it was postulated that the fitness decline at the large effective population size was due to selection moving the population mean for body weight and a trait positively correlated genetically with body weight (i.e., percent body fat) away from an optimum

scholarly journals THE EFFECT OF FEEDING MULTI-NUTRIENT MINI BLOCKS AND PELLETED DIETS ON THE GROWTH OF RABBITS

2021 ◽  
Vol 24 (2) ◽  
pp. 147-149
Author(s):  
W. O. Biobaku ◽  
E. B. Oguntona
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Feed Efficiency ◽  
Crude Protein ◽  
Body Weight Gain ◽  
Basal Diet ◽  
The Body ◽  
Ether Extract ◽  
Crude Fibre ◽  
Effect Of Feeding

The effect of substituting pelleted diets with multinutrient block on the growth of weanling rabbits was studied. The pelleted diets and the multinutrient blocks contained crude protein 23.31% and 24.24%, crude fibre 21.65 and 23.00% ether extract 10.44% and 10.97% respectively. The body weight gain (10.58g/day), feed intake (110,20g/day) and feed efficiency ration (0.58) of rabbits fed multinutrient blocks were non-significantly higher by 8.50%, 10.65% and 10.34% respectively, that those rabbits fed with pelleted basal diet.  

scholarly journals PARTITIONING AVERAGE AND HETEROTIC COMPONENTS OF DIRECT AND MATERNAL GENETIC EFFECTS ON GROWTH IN MICE USING CROSSFOSTERING TECHNIQUES

Genetics ◽  
1976 ◽  
Vol 84 (1) ◽  
pp. 113-124
Author(s):  
J Nagai ◽  
H Bakker ◽  
E J Eisen
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Genetic Effects ◽  
Control Group ◽  
Correlated Responses ◽  
Secondary Importance ◽  
Body Weights ◽  
Weight Gains ◽  
The Individual ◽  
Linear Contrasts

ABSTRACT Crossfostering was performed using lines selected for increased 6-week body weight (H6) and increased 3-to 6-week postweaning gain (M16) and their reciprocal F1 crosses as nurse dams in the selected crossfostering group, and base population controls (C2, ICR) and their reciprocal F1 crosses in the control group. The offspring suckled were H6, M16 and F2 crosses in the selected group, and C2, ICR and their F2 crosses in the control group. Measurements taken on the individual offspring were body weights at birth (WB) and at 12, 21, 31, 42, and 63 days (W12, W21, W31, W42 and W63, respectively) and weight gains between adjacent ages (GB-12, G12–21, G21–31, G31–42 and G42–63, respectively). Least squares constants fitted to populations of genetic and nurse dams were used to calculate specific linear contrasts. Correlated responses to selection in average direct genetic effects were significant and positive for all traits examined in both H6 and M16, while the correlated responses in average maternal genetic effects were negative in M16 and negligible in H6. Selection response was primarily due to average direct genetic effects while the contribution of average maternal genetic effects was of secondary importance. The response in average direct genetic effects was smaller in M16 than in H6 through weaning (WB, W12 and W21), but was larger in M16 for postweaning weights (W31, W42 and W63). The correlated responses in average maternal genetic effects were consistently smaller in M16 than in H6. Direct heterosis was significant for all traits except for G12–21 and G42–63 in the control group, whereas maternal heterosis was significant for weight gains at early ages and for body weights. Direct heterosis tended to be larger than maternal heterosis in both selected and control crosses. Percent direct heterosis for body weight was larger in the selected crosses relative to the control crosses through 31 days of age, but the trend was reversed by 63 days. Percent maternal heterosis was consistently larger in the selected crosses.

Relative growth of the major body componrnts of the southern elephant seal. Mirounga leonina (L.)

1969 ◽  
Vol 17 (1) ◽  
pp. 153 ◽  
Author(s):  
MM Bryden
Keyword(s):  
Body Weight ◽  
Elephant Seal ◽  
The Body ◽  
Developmental Changes ◽  
Postnatal Life ◽  
Main Body ◽  
Mirounga Leonina ◽  
Suckling Period ◽  
Relative Growth ◽  
Body Components

Relative growth of the main body components (fat, muscle, bone, viscera, and skin) is dealt with in detail, particularly in animals which had not attained nutritional independence; a period of accelerated growth in these animals was followed by a complete fast of 5-7 weeks. Seal pups more than trebled their birth weight over the 23-day suckling period, a high percentage of this increase being attributed to deposition of the blubber. During the postweaning fast, muscle, fat, and viscera were lost at a rate similar to the rate of gain during the suckling period, whereas bone and skin did not alter significantly in weight during the fasting phase. After the pups attained nutritional independence, the main body components grew at the same rate as body weight, except that in males at puberty muscle weight increased relatively more quickly than the body weight, and at the expense of bone and viscera. Developmental patterns within the musculature were studied by dissecting the muscles individually, and grouping them according to anatomical location into 10 muscle groups. The development of the musculature during the suckling period tended to be reversed during the postweaning fast. During these two phases, elephant seal pups remained on land most of the time. Developmental changes in the musculature occurred after the seal entered the water, and were modified slightly in sexually mature bulls. These changes are associated with the ecology of this group of animals. Evidence is given that developmental changes within the musculature occurred in response to functional requirements, and it is proposed that this could be brought about by alteration of growth gradients, which are not necessarily reversible during body weight loss. Individually dissected bones were allotted to one of five major anatomical groups, and the weight of the bone groups expressed as a percentage of the total bone weight was used in assessing the results of the changes in bone weight distribution with age. The weight of the bone groups was compared with the corresponding groups in new-born animals. It was found that those bones which are most important structurally (enabling the seal to meet the demands placed on it by the force of gravity) grew most during postnatal life, and that developmental changes in the skeleton occurred in response to functional demands. The winter "rest" periods that immature animals spend ashore are apparently necessary to direct the development of the growing animal to meet these structural demands when it hauls out on land, which it must do later in life to moult and to breed.

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