scholarly journals Effects of selection on growth, body composition and food intake in mice: II. Correlated responses in reproduction

1984 ◽  
Vol 44 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Forbes D. Brien ◽  
Gillian L. Sharp ◽  
William G. Hill ◽  
Alan Robertson
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Food Intake ◽  
Litter Size ◽  
Reproductive Performance ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Primary Reason ◽  
Correlated Responses ◽  
Fat Percentage

SummaryFemale reproductive performance is reported in mice selected for ten generations for one of three criteria: either appetite (A), fat percentage (F) or total lean mass (P). For each criterion lines were selected for high (H) or low (L) performance, with contemporary unselected controls (C). In the A and P lines, litter size changed in the direction of the selected criterion, the changes being larger and more rapidly established in the A than in the P lines. At generation 10, the differences in litter size between high and low lines were 2·6 live young born in the A lines, and 1·0 live young born in the P lines. The differences in 6-week weight between the high and low lines were 3·5 g in the A lines, 6·5 g in the P lines. Changes in ovulation rate were the primary reason for changes in litter size, the differences between the high and low lines being 3·8 corpora lutea for the A lines, and 3·1 corpora lutea for the P lines. Fitting body weight at mating as a covariate within lines in the analysis of ovulation rate and live foetus number removed the differences between the high and low selected P lines, but not those in the A lines. The high and low selected A and P lines did not differ in prenatal survival. There were no consistent differences in litter size, ovulation rate or pre-natal survival in the F lines.

THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR
Keyword(s):  
Body Weight ◽  
Mortality Rate ◽  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Ovulation Rate ◽  
Genetic Groups ◽  
Linear Regressions ◽  
Size At Birth

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities

scholarly journals Litter size components traits in two Algerian rabbit lines

2021 ◽  
Vol 29 (1) ◽  
pp. 51
Author(s):  
Rafik Belabbas ◽  
Maria de la Luz García ◽  
Hacina AinBaziz ◽  
Ali Berbar ◽  
Maria José Argente
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Principal Components ◽  
Local Population ◽  
The Body ◽  
Ovulation Rate ◽  
Phenotypic Correlation ◽  
Limiting Factor ◽  
Corpora Lutea ◽  
Synthetic Line

<p>The aim of this study was to estimate the limiting litter size components in rabbit females from a Synthetic line (n=32) and a Local population (n=34). Ovulation rate, number of implanted and live embryos were counted by laparoscopy at 12 d after mating. Prolificacy (total newborn, number born alive and mortality) and embryonic, foetal and prenatal survival at day of birth of the 3<sup>rd</sup> gestation were measured. The analysed traits were body weight of the female at mating, ovulation rate, implanted, live and resorbed embryos, embryonic, foetal and prenatal survival, as well as total newborn, number born alive and mortality at birth. Synthetic line females had a higher ovulation rate compared to the Local population (11.03±0.23 vs. 8.41±0.23 corpora lutea; <em>P</em>&lt;0.0001). Synthetic line displayed a higher number of implanted embryos (10.00±0.25 vs. 7.85±0.25 embryos; <em>P</em>&lt;0.0001). No difference was found between groups for number of resorbed embryos. Similar embryonic, foetal and prenatal survival rates were reported between the Synthetic line and the Local population. Additionally, total newborn was higher in the Synthetic line than in the Local population (+1.46 kits; <em>P</em>&lt;0.05). A principal components analysis was performed. The first four principal components (PC) explained more than 90% of the total variation in both lines. Total newborn, number born alive and live embryos were the main variables defining the 1<sup>st</sup> PC. Resorbed embryos and foetal survival were located in the 2<sup>nd</sup> PC. Ovulation rate and embryonic survival were the predominant variables defining the 3<sup>rd</sup> PC. The body weight of females was located in the 4<sup>th</sup> PC. The phenotypic correlation between total newborn and its components were high and positive in both lines, except for ovulation rate and total newborn, where it was moderate in Synthetic line. In conclusion, the females from Synthetic line have a higher total newborn than those from Local population, as a consequence of a higher number of released oocytes and embryos that successfully reach implantation. However, a higher uterine crowding in Synthetic line seems to limit survival of foetuses that reach term of gestation, while ovulation rate is the principal limiting factor of total newborn in Local population.</p>

The effect of food intake prior to farrowing on the body composition of first-litter sows

1988 ◽  
Vol 1988 ◽  
pp. 42-42
Author(s):  
B.P. Mullan ◽  
I.H. Williams
Keyword(s):  
Body Composition ◽  
Food Intake ◽  
Litter Size ◽  
Reproductive Performance ◽  
Composition Studies ◽  
Nutritional Stress ◽  
Quantitative Information ◽  
The Body ◽  
Body Reserves ◽  
Effect Of Food

Body reserves are important in reproduction because they can be used by the sow to buffer the nutritional stress through a low intake of food in lactation (Mullan and Williams, 1988). Quantitative information on the body composition of first-litter sows during lactation is clearly required to establish what body reserves are mobilized during lactation, and how this relates to subsequent reproductive performance. The aim of this study was to quantify the body reserves of first-litter sows at farrowing and to measure the change in these reserves during lactation.Animals selected for body composition studies were from the High-High, High-Low, Low-High and Low-Low groups of an experiment described by Mullan and Williams (1988). Animals were selected according to bodyweight, depth of backfat and litter size, with the object to have animals that were representative of those in the earlier experiment. Sows were removed from their litter, weighed and the depth of backfat measured by ultrasound at the P2. Within three hours of weaning animals were slaughtered and the head, trotters, tail, viscera one side of the carcass were frozen, minced and chemically analysed for lipid, protein, water and ash.

scholarly journals Effects of flush feeding strategy before breeding on reproductive performance of modern replacement gilts: impacts on ovulation rate and litter traits

2020 ◽  
Vol 98 (6) ◽  
Author(s):  
André L Mallmann ◽  
Lidia S Arend ◽  
Gabriela S Oliveira ◽  
Ana P G Mellagi ◽  
Rafael R Ulguim ◽  
...  
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Feeding Strategy ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Breeding Cycle ◽  
Corpora Lutea ◽  
Embryo Survival ◽  
Estrous Cycles ◽  
Litter Traits

Abstract AbstractThe effects of two feed levels offered during two estrous cycles before insemination were evaluated on the reproductive performance of gilts. A total of 93 gilts (PIC Hendersonville, TN) were individually housed and manually fed twice a day with 2.1 or 3.6 kg/d of a corn and soybean meal-based diet (3.15 Mcal ME/kg and 0.64% standardized ileal digestible lysine), during two estrous cycles before breeding (cycle 1, between first and second estrus; cycle 2, between second and third estrus). Gilts were weighed at the beginning of the experiment, at second and third estrus, and at slaughter (30.2 ± 1.2 d of gestation). Follicles were counted at second estrus, and the embryo-placental units and the corpora lutea were individually counted, measured, and weighed at slaughter. Gilts fed 3.6 kg/d had greater BW gain during cycle 1 and cycle 2 (P &lt; 0.001; + 9.8 kg and + 10.0 kg, respectively) becoming heavier at second and third estrus (P &lt; 0.001). At second estrus, gilts fed 3.6 kg/d had 1.6 more medium-large follicles (P = 0.074) but no difference in follicle size (P = 0.530) was observed. Gilts fed 3.6 kg/d in cycle 1 or cycle 2 had a greater ovulation rate at third estrus (P &lt; 0.016) than those receiving 2.1 kg/d. Also, 3.6 kg/d in cycle 2 increased early embryo mortality (P = 0.006; 2.3 vs. 1.1 dead embryos) and consequently reduced total embryo survival (P = 0.002; 84.6 vs. 90.1%). Gilts fed 3.6 kg/d during cycle 1 had two more total embryos (P &lt; 0.001; 17.2 vs. 15.1) and two more vital embryos on day 30 (P &lt; 0.001; 16.7 vs. 14.5) in comparison with gilts fed 2.1 kg/d. The coefficient of variation for placental length was greater for gilts fed 3.6 kg/d during cycle 1 (P = 0.003). No further significant effects of feeding levels were observed on embryo and placental traits (P ≥ 0.063). These results suggest that the feeding level during the first cycle after pubertal estrus is crucial to set ovulation rate and potential litter size for breeding at next estrus. However, flush feeding gilts before insemination can negatively impact litter size by reducing embryo survival when breeding at third estrus.

The effects of body weight and level of nutrition before, during, and after joining on ewe fertility

1967 ◽  
Vol 7 (25) ◽  
pp. 126 ◽  
Author(s):  
ID Killeen
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
Ovulation Rate ◽  
Multiple Birth ◽  
Corpora Lutea ◽  
Body Weights ◽  
Before And After ◽  
Independent Effects ◽  
Experimental Treatments ◽  
High Level

Four experiments were designed to assess the independent effects of body weight and nutritional level on the reproductive performance of Border Leicester x Merino ewes. Ewes in experiments 1, 2, and 3 were joined in summer (December-January) and in experiment 4 in autumn (March-April). The reproductive performance of two groups of ewes in experiment 1, joined at different body weights, was assessed from mating and lambing data. A factorial (3 x 2 x 2) design was used for experiments 2, 3, and 4. The experimental treatments consisted of different levels of nutrition applied before and after mating. The reproductive performance of ewes in experiment 2 was assessed from mating and lambing data. Ewes in experiments 3 and 4 were slaughtered 19-28 days after mating, and their genitalia were observed for presence of corpora lutea and embryos. Body weight at mating and level of nutrition during three weeks before mating independently affected the multiple birth or ovulation rate. High body weight at mating was consistent with a high multiple birth or ovulation rate, and a higher proportion of the ewes receiving a high level of nutrition during the three weeks before mating (i.e. flushed ewes) had multiple births or multiple ovulations. The results also demonstrated that above 90-100 lb, the proportion of ewes mating and becoming pregnant was relatively independent of body weight at joining. The level of nutrition and body weight had only minor effects on early reproductive failure, but there was a higher proportion of egg wastage from multiple ovulation ewes than from single ovulation ewes.

Food efficiency in relation to estimated growth of body components in cattle

1975 ◽  
Vol 20 (3) ◽  
pp. 315-335 ◽  
Author(s):  
L. S. Monteiro
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Linear Model ◽  
Unit Weight ◽  
Fat Percentage ◽  
Non Linear ◽  
The Difference ◽  
Maintenance Requirements

SUMMARYA model is proposed to establish a functional relationship between food intake, weight gain and body composition during growth, based on the differential energy requirements for fat, fat-free tissues and contents of the digestive tract. If constant specific nutrient requirements are assumed for fat and fat-free tissues, these requirements can be directly estimated from changes in food intake and body composition during growth. By introducing an allometric function relating changes in fat-free tissue to changes in body weight, the model is extended to include situations where direct measures of body composition are not available. This enabled the model to be fitted to data on food intake, body weight and growth rate up to 2 years of age in Friesians and Jerseys fed ad libitum on a complete diet. The nonlinear model is contrasted with a linear relationship where food intake i s related to body weight and weight gain. The linear model was unable to account for the changes in food intake over the whole period of growth. The non-linear model allowed a gradual decline n i maintenance requirements per unit weight and indicated an increase in the net conversion coefficient of food into gain, consistent with an increase from early to late growth in proportion of fat deposited.For the period studied the Jerseys were less efficient in transforming food into weight gain than Friesians. On the non-linear model, about half of the difference was attributable to the higher metabolic rate per unit weight of Jerseys, the remainder to poorer utilization of nutrients for weight gain. If, as the model indicated the conversion coefficients of food into body constituents were the same in the two breeds, the difference in efficiency may be attributable to a higher proportion of fat in the overall gain of Jerseys. The pattern of estimated fat deposition also differed in the two breeds with Jerseys appearing to be less mature in fat percentage at all stages.

scholarly journals Effects of selection on growth, body composition, and food intake in mice: III. Correlated responses:growth, body composition, food intake and efficiency and catabolism

1985 ◽  
Vol 46 (1) ◽  
pp. 57-74 ◽  
Author(s):  
S. C. Bishop ◽  
W. G. Hill
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Food Intake ◽  
Lean Mass ◽  
Growth Period ◽  
Carcass Composition ◽  
Fat Pad ◽  
Fat Percentage ◽  
Maintenance Requirements ◽  
Old Mice

SUMMARYWeekly food intake and body weight were measured from 3 to 17 weeks of age on mice selected 14 generations for increased and decreased values of one of three criteria: appetite (A) as measured by 4- to 6-week food intake, adjusted by phenotypic regression to minimize change in 4-week body weight; fat percentage (F), using the ratio of gonadal fat pad weight to body weight at 10 weeks of age and total lean mass (protein, P), using the index body weight in 10-week males— (8 × gonadal fat pad weight). Carcass composition analyses were undertaken on the 17-week-old mice, and are presented along with composition data for younger mice from earlier generations. The high intake A line mice are larger, eat more, have higher maintenance requirements and are slightly leaner than the low intake A line mice, but are no more efficient. The increased lean mass P line mice are much larger, eat more and are more efficient than the decreased lean mass P line mice, but show little difference in maintenance or carcass composition. The (much) fatter F line mice are larger, more efficient and eat more during the rapid growth period than their leaner F line counterparts, but show no difference in lean mass or maintenance requirements. These results provide implications about the relationships between the input (intake) and output (maintenance and lean and fat deposition) components of growth.

Body Composition Modifications Due to the “Search, Rescue and Survival Training” in Male Military Firefighter Cadets

2021 ◽  
Author(s):  
Thiago Ramos de Barros ◽  
Verônica Pinto Salerno ◽  
Thalita Ponce ◽  
Míriam Raquel Meira Mainenti
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Repeated Measures ◽  
Food Restriction ◽  
Physical Exertion ◽  
High Energy ◽  
The Body ◽  
Fat Free Mass ◽  
Sleep Restriction ◽  
Fat Percentage

ABSTRACT Introduction To train and prepare cadets for a career as firefighters in Rio de Janeiro, the second-year students of the Officers Training Course are submitted to a Search, Rescue, and Survival Training (SRST) course, which is characterized by long periods of high physical exertion and sleep restriction during a 9-day instruction module, and food restriction during a 7-day survival module. The present study investigated changes in the body composition of 39 male cadets submitted to SRST during training and 4 weeks of recovery with no restrictions in food consumption. Materials and Methods Each cadet was evaluated by anthropometric measurements at six time points: pre-SRST; after the first module; after the second module; and after 1, 2, and 4 weeks of recovery. Measurements included body girths and skinfolds, to estimate trunk (chest and waist) and limbs (arm and thigh) dimensions, as well as body composition. Repeated measures ANOVA and Friedman test were applied (depending on each data distribution). Results Statistically significant decreases in body weight (76.2; 69.8-87.2 to 63.9; 58.9-73.5 kg) and fat free mass (FFM, 69.2; 63.7-77.2 to 60.1; 56.2-68.0 kg) were observed following the second module of SRST. Following a single week of recovery, the FFM returned to pre-SRST values. Body weight returned to pre-training levels in 2 weeks. Body fat percentage and mass also significantly decreased during SRST (9.0; 7.7-12.3 to 6.5; 5.1-9.3% and 6.9; 5.6-10.0 to 6.9; 5.6-10.0 kg, respectively), which showed a slower and more gradual recovery that reached pre-SRST values after 4 weeks. The girths of arm, thigh, chest and waist significantly decreased due to SRST. The girths of the limbs (arm and thigh) returned to pre-training values after one month of recovery, while the girths of the trunk (chest and waist) did not return to pre-SRST values during the study period. Conclusions The findings suggest that men who experience periods of high energy demands and sleep restriction followed by a period of food restriction will endure unavoidable physical consequences that can be mostly reversed by a 1-month recovery.

Fertility in Cheviot ewes. 2. The effect of level of pre-mating nutrition on ovulation rate and early embryo mortality in North and South Country Cheviot ewes in moderately-good condition at mating

1979 ◽  
Vol 29 (1) ◽  
pp. 17-23 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney ◽  
W. F. Smith
Keyword(s):  
Food Intake ◽  
Good Condition ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Restricted Feeding ◽  
Embryo Mortality ◽  
The North ◽  
Breed Difference ◽  
High Level

ABSTRACTIn two experiments over 2 years, 57 North Country Cheviot and 82 South Country Cheviot hill ewes were differentially group-fed indoors over a 2-month period to achieve either good or moderate body con- dition. Over 5 weeks prior to mating, ewes in good condition were brought down in condition by restricted feeding and ewes in mod- erate condition were raised in condition by a high level of feeding. The ewes were thus in moderately-good condition at mating. After mating, ewes were maintained in this condition until killed either on return to service or at 29 ± 8 days for counts of corpora lutea and viable embryos.Ovulation rate in each breed was positively related to the level of pre-mating food intake at the condition level studied. Embryo mortality, as ova loss, was not influenced overall by the level of pre-mating food intake but loss of multiple-shed ova was greater than that of single-shed ova in ewes which had been on restricted feeding before mating. Although a greater proportion of ewes in the North Country Cheviot breed were not pregnant at slaughter, this could not be identified as a breed difference since the breeds were studied in different years.

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